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1

Speciation of copper in a contaminated soil during H 3PO 4-assisted EKR  

Microsoft Academic Search

Speciation of copper in a contaminated soil during electrokinetic remediation (EKR) assisted by H3PO4 was studied by in situ X-ray absorption near edge structural (XANES) spectroscopy. The least-square fit of the XANES spectrum showed that CuCO3 (68%) and CuCl2 (32%) were the major copper species in the contaminated soil. In the presence of H3PO4 (40%), most of CuCl2 and about

S.-H. Liu; H. Paul Wang; M. Y. Yu; Y.-J. Huang; H.-C. Wang

2005-01-01

2

Hydrolysis of tetracalcium phosphate in H3PO4 and KH2PO4  

Microsoft Academic Search

The activity product of tetracalcium phosphate (TTCP, Ca4(PO4)2O), was determined at 37°C, and the hydrolysis of TTCP was investigated in 0.01–0.1 mol l-1 H3PO4 and KH2PO4 solutions by means of calcium and phosphorus analyses, X-ray diffraction and infrared analysis. The activity product, defined as Ksp=(Ca2+)4 (PO43-)2 (OH-)2, was 37.36 as pKsp, which was smaller than that previously reported (42.4). TTCP

S. Matsuya; S. Takagi; L. C. Chow

1996-01-01

3

Oscillation in the Kmno 4?NH 2CH 2COOH?H 3PO 4 Cstr system  

NASA Astrophysics Data System (ADS)

A novel chemical oscillating reaction in the KMnO 4?NH 2CH 2COOH?H 3PO 4 CSTR system in the presence and absence of Ag + has been described. The reaction kinetics in a closed Mn0 4-?NH 2CH 2COOH?H 3PO 4 system has been analyzed and a possible mechanism has been proposed. The catalytic effect of Ag + in the above reaction has also been studied.

Li, Hexing; Huang, Xiaojun; Deng, Jingfa

1996-08-01

4

Physical and chemical properties of carbons synthesized from xylan, cellulose, and Kraft lignin by H 3PO 4 activation  

Microsoft Academic Search

Physical and chemical properties of activated carbons produced from commercial xylan, cellulose, and Kraft lignin by H3PO4 activation at various process conditions were studied. The results show that the more reactive the precursor under acidic conditions, the easier the porosity development, particularly mesoporosity. In addition, Boehm titration and Fourier Transform Infrared Spectroscopy (FTIR) characterization results demonstrated that the functional groups

Yanping Guo; David A. Rockstraw

2006-01-01

5

A study of rosemary oil as a green corrosion inhibitor for steel in 2 M H3PO4  

Microsoft Academic Search

Purpose – To evaluate the effect of natural rosemary oil as non toxic inhibitor on the corrosion of steel in H3PO4 media at various temperatures. Design\\/methodology\\/approach – The oil was hydro-distilled. The oil was used as inhibitor in various corrosion tests. Gravimetric and electrochemical techniques were used to characterise the corrosion mechanism. Findings – Chromatographic analysis by GC showed that

M. Bendahou; M. Benabdellah; B. Hammouti

2006-01-01

6

Standard thermodynamic properties of H3PO4(aq) over a wide range of temperatures and pressures.  

PubMed

The densities and heat capacities of solutions of phosphoric acid, 0.05 to 1 mol kg-1, were measured using flow vibrating tube densitometry and differential Picker-type calorimetry at temperatures up to 623 K and at pressures up to 28 MPa. The standard molar volumes and heat capacities of molecular H3PO4(aq) were obtained, via the apparent molar properties corrected for partial dissociation, by extrapolation to infinite dilution. The data on standard derivative properties were correlated simultaneously with the dissociation constants of phosphoric acid from the literature using the theoretically founded SOCW model. This made it possible to describe the standard thermodynamic properties, particularly the standard chemical potential, of both molecular and ionized phosphoric acid at temperatures up to at least 623 K and at pressures up to 200 MPa. This representation allows one to easily calculate the first-degree dissociation constant of H3PO4(aq). The performance of the SOCW model was compared with the other approaches for calculating the high-temperature dissociation constant of the phosphoric acid. Using the standard derivative properties, sensitively reflecting the interactions between the solute and the solvent, the high-temperature behavior of H3PO4(aq) is compared with that of other weak acids. PMID:17201442

Ballerat-Busserolles, Karine; Sedlbauer, Josef; Majer, Vladimir

2007-01-11

7

Role of surface reactions in the transpassive dissolution of ferrous alloys in concentrated H 3PO 4  

NASA Astrophysics Data System (ADS)

The transpassive dissolution of a range of ferrous alloys (Fe-12% Cr, Fe-12% Cr-5% Mo, Fe-25% Cr, Fe-25% Cr-10% Mo) in concentrated H 3PO 4 was studied within the frames of an investigation of electropolishing mechanisms. Measurements by the contact electric resistance (CER) technique have demonstrated that in the transpassive region, the resistance of the anodic film first decreases with increasing potential due to enhanced conductivity of that film and then increases at higher potentials, indicating transpassive film growth. The release of soluble Cr(VI) as detected by rotating ring-disc measurements is the higher, the higher the Cr content in the alloy, and further increases upon addition of 10% Mo to the Fe-Cr alloys. Impedance spectra in the transpassive region have been found to include contributions both from the anodic film and a multistep transpassive dissolution reaction at the film/solution interface. The results were interpreted using a generalised model of transpassive dissolution. The kinetic parameters of the process were determined and the influence of alloy composition on their values is discussed in relation to the processes of anodic surface treatment.

Betova, Iva; Bojinov, Martin; Tzvetkoff, Tzvety

2003-12-01

8

Improvement in the etching performance of the acrylonitrile-butadiene-styrene resin by MnO2-H3PO4-H2SO4 colloid.  

PubMed

The present study aimed to evaluate the surface etching of the acrylonitrile-butadiene-styrene (ABS) resin in the MnO2-H3PO4-H2SO4 colloid. To enhance the soluble Mn(IV) ion concentration and improve the etching performance of ABS resin, H3PO4 was added as a complexing agent into the MnO2-H2SO4 etching system. The effects of the H2SO4 concentration and etching time on the surface topography, surface roughness, adhesion strength, and the surface chemistry of the ABS substrates were investigated. The optimal oxidation potentials of MnO2 in the colloids decreased from 1.426 to 1.369 V with the addition of H3PO4. Though the etching conditions changed from 70 °C for 20 min to 60 °C for 10 min, the adhesion strength between the ABS substrates and electroless copper film increased from 1.19 to 1.33 KN/m after etching treatment. This could be attributed to the significant increase of the soluble Mn(IV) ion concentration in the MnO2-H3PO4-H2SO4 colloid. The surface chemistry results demonstrated that the oxidation reaction of -C?C- bonds in the polybutadiene phase was accelerated in the etching process by the addition of H3PO4, and the abundant -COOH and -OH groups were formed rapidly on the ABS surface with the etching treatment. These results were in agreement with the results of surface scanning electron microscopic observations and adhesion strength measurement. The results suggested that the MnO2-H3PO4-H2SO4 colloid was an effective surface etching system for the ABS surface roughness. PMID:23611532

Zhao, Wenxia; Ding, Jie; Wang, Zenglin

2013-05-09

9

Studies on the identification of the heteropoly acid generated in the H 3PO 4–WO 3–Nb 2O 5 catalyst and its thermal transformation process  

Microsoft Academic Search

The precursor of the mixed metal oxide catalyst composed of H3PO4–WO3–Nb2O5, which exhibits excellent activity in Friedel–Crafts alkylations, was identified with 31P NMR. It was revealed that the Keggin-type mixed heteropoly acid, H4PNbW11O40, was spontaneously generated during preparation of the H3PO4–WO3–Nb2O5 catalyst. The partial decomposition of H4PNbW11O40 occurred in the temperature range of 673–823 K to give an amorphous oxide

Kazu Okumura; Katsuhiko Yamashita; Kazuhiro Yamada; Miki Niwa

2007-01-01

10

Dissolution mechanism of crystalline cellulose in H3PO4 as assessed by high-field NMR spectroscopy and fast field cycling NMR relaxometry.  

PubMed

Many processes have been proposed to produce glucose as a substrate for bacterial fermentation to obtain bioethanol. Among others, cellulose degradation appears as the most convenient way to achieve reliable amounts of glucose units. In fact, cellulose is the most widespread biopolymer, and it is considered also as a renewable resource. Due to extended intra- and interchain hydrogen bonds that provide a very efficient packing structure, however, cellulose is also a very stable polymer, the degradation of which is not easily achievable. In the past decade, researchers enhanced cellulose reactivity by increasing its solubility in many solvents, among which concentrated phosphoric acid (H(3)PO(4)) played the major role because of its low volatility and nontoxicity. In the present study, the solubilization mechanism of crystalline cellulose in H(3)PO(4) has been elucidated by using high- and low-field NMR spectroscopy. In particular, high-field NMR spectra showed formation of direct bonding between phosphoric acid and dissolved cellulose. On the other hand, molecular dynamics studies by low-field NMR with a fast field cycling (FFC) setup revealed two different H(3)PO(4) relaxing components. The first component, described by the fastest longitudinal relaxation rate (R(1)), was assigned to the H(3)PO(4) molecules bound to the biopolymer. Conversely, the second component, characterized by the slowest R(1), was attributed to the bulk solvent. The understanding of cellulose dissolution in H(3)PO(4) represents a very important issue because comprehension of chemical mechanisms is fundamental for process ameliorations to produce bioenergy from biomasses. PMID:19769370

Conte, Pellegrino; Maccotta, Antonella; De Pasquale, Claudio; Bubici, Salvatore; Alonzo, Giuseppe

2009-10-14

11

The effect of modification of KH 2PO 4 hardening liquid with H 3PO 4 and chitosan on setting reactions and compressive strength of calcium phosphate cement  

Microsoft Academic Search

The setting processes and mechanical properties of tetracalcium phosphate (TTCP) -monetite cements with H3PO4 and chitosan modified KH2PO4 hardening liquid have been studied. From XRD phase analysis, it was found that brushite was created in the first stage of the setting process by the interaction between phosphate compounds in hardening liquids and TTCP. Calcium deficient hydroxyapatite was the final product

?. Medvecký; R. Štulajterová; J. Brian?in; J. ?urišin

2009-01-01

12

Characterization and lead adsorption properties of activated carbons prepared from cotton stalk by one-step H 3PO 4 activation  

Microsoft Academic Search

Activated carbons were prepared from cotton stalk by one-step H3PO4 activation and used as adsorbent for the removal of lead(II). Taguchi experimental design method was used to optimize the preparation of the adsorbents. The results showed that the optimized conditions were: impregnation with a 50% (w\\/v) phosphoric acid solution with a mass ratio of 3:2 and activation temperature at 500°C

Kunquan Li; Zheng Zheng; Ye Li

2010-01-01

13

The corrosion of tantalum in oxidizing sub- and supercritical aqueous solutions of HCl, H2SO4 and H3PO4  

Microsoft Academic Search

The corrosion of tantalum was investigated in sub- and supercritical oxidizing solutions of hydrochloric, sulfuric and phosphoric acid at temperatures between 360 and 500 °C. The corrosion rates in HCl and H2SO4 increased strongly above the critical temperature of water, which was attributed to a phase transformation from vitreous to crystalline Ta2O5. Corrosion rates in H3PO4 were low at all

C. Friedrich; P. Kritzer; N. Boukis; G. Franz; E. Dinjus

1999-01-01

14

Solubility in the System (NH4)2HPO4-(NH4)2SO4-H2SO4-H3PO4-H2o.  

National Technical Information Service (NTIS)

Data in the literature are interpreted and solubility diagram of the system (NH4)2HPO4-(NH4)2SO4-H2SO4-H3PO4-H2O, the 25C isotherm, is constructed. Lines of common crystallization of (NH4)2SO4 + (NH4)3H(SO4)2; (NH4)2SO4 + NH4H2PO4.NH4HSO4; (NH4)2SO4 + NH4...

Y. S. Mishchenko M. L. Chepelevetskii

1966-01-01

15

Separative recovery with lime of phosphate and fluoride from an acidic effluent containing H3PO4, HF and/or H2SiF6.  

PubMed

Fluoride content and flow-rate of fertilizer plant wastewater from phosphoric acid and/or triple superphosphate (TSP) production lead to the discharge of several thousand tons of fluoride (F(-)) per year and even more for phosphate (PO4(3-)). Since sustainability is an important environmental concern, the removal methods should allow phosphorus and fluoride to be recycled as a sustainable products for use as raw materials either in agricultural or industrial applications. In the present work, separative recovery with lime of these two target species was investigated. A preliminary speciation study, carried out on the crude effluent, showed that two forms of fluoride: HF and H2SiF6 are present in a highly acidic medium (pH approximately 2). Evidence that fluoride is present under both free (HF) and combined (H2SiF6) forms, in the phosphate-containing effluent, was provided by comparing potentiometric titration curves of a crude wastewater sample and synthetic acid mixtures containing H3PO4, HF and H2SiF6. In a second step synthetic effluent containing mixtures of the following acids: HF, H2SiF6 and H3PO4, were treated with lime. The behaviour of these compounds under lime treatment was analysed. The data showed that fluoride has a beneficial effect on phosphate removal. Moreover, by acting on the precipitation pH, a "selective" recovery of fluoride and phosphate ions was possible either from phosphoric acid/hydrofluoric acid or phosphoric acid/hexafluorosilicic acid mixtures. Indeed, the first stage of the separative recovery, led to a fluoride removal efficiency of 97-98% from phosphoric acid/hydrofluoric acid mixture. It was of 93-95% from phosphoric acid/hexafluorosilicic acid mixture. During the second stage, the phosphate precipitation reached 99.8% from both acidic mixtures whereas it did not exceed 82% from a solution containing H3PO4 alone. The XRD and IR analyses showed that during lime treatment, a H2SiF6 hydrolysis occurred, instead of CaSiF6 solid formation, leading to CaF2 precipitate. Calcium fluoride and calcium phosphate based-by-products resulting from the two-step treatment process can be used as raw materials in several industrial sectors, such as ceramic and phosphate fertilizer industries. PMID:19524365

Gouider, Mbarka; Feki, Mongi; Sayadi, Sami

2009-05-21

16

Investigation of the inhibitive effect of triphenyltin 2-thiophene carboxylate on corrosion of steel in 2 M H3PO4 solutions  

NASA Astrophysics Data System (ADS)

A new organic compound was synthesised and tested as corrosion inhibitor of steel in phosphoric acid medium using gravimetric, electrochemical polarisation and electrochemical impedance spectroscopy (EIS) measurements. Results obtained show that the inhibitor studied is a good cathodic inhibitor. EIS results show that the change in the impedance parameters (RT and Cdl) with concentration of triphenyltin 2-thiophene carboxylate (TTC) is indicative of the adsorption of molecules leading to the formation of a protective layer on the surface of steel. The effect of the temperature on the steel corrosion in 2 M H3PO4 and with addition of various concentrations of TTC in the range of temperature 298 348 K was studied. The associated apparent activation corrosion energy has been determined.

Benabdellah, M.; Aouniti, A.; Dafali, A.; Hammouti, B.; Benkaddour, M.; Yahyi, A.; Ettouhami, A.

2006-09-01

17

Carbons prepared from coffee grounds by H3PO4 activation: characterization and adsorption of methylene blue and Nylosan Red N-2RBL.  

PubMed

Activated carbons were prepared by the pyrolysis of coffee grounds impregnated by phosphoric acid at 450 degrees C for different impregnation ratios: 30, 60, 120 and 180 wt.%. Materials were characterized for their surface chemistry by elemental analysis, "Boehm titrations", point of zero charge measurements, Infrared spectroscopy, thermogravimetric analysis (TGA); as well as for their porous and morphological structure by Scanning Electron Microscopy (SEM) and nitrogen adsorption at 77K. The impregnation ratio was found to govern the porous structure of the prepared activated carbons. Low impregnation ratios (<120 wt.%) led to essentially microporous and acidic activated carbons whereas high impregnation ratios (>120 wt.%) yielded to essentially mesoporous carbons with specific surface areas as high as 925 m(2)g(-1), pore volume as large as 0.7 cm(3)g(-1), and neutral surface. The activated carbons prepared from coffee grounds were compared to a commercial activated carbon (S(BET) approximately 1400 m(2)g(-1)) for their adsorption isotherms of methylene blue and "Nylosan Red N-2RBL", a cationic and anionic (azo) dye respectively. The mesoporous structure of the material produced at 180 wt.% H(3)PO(4) ratio was found to be appropriate for an efficient sorption of the latter azo dye. PMID:19942347

Reffas, A; Bernardet, V; David, B; Reinert, L; Lehocine, M Bencheikh; Dubois, M; Batisse, N; Duclaux, L

2009-10-30

18

Characterization and lead adsorption properties of activated carbons prepared from cotton stalk by one-step H3PO4 activation.  

PubMed

Activated carbons were prepared from cotton stalk by one-step H(3)PO(4) activation and used as adsorbent for the removal of lead(II). Taguchi experimental design method was used to optimize the preparation of the adsorbents. The results showed that the optimized conditions were: impregnation with a 50% (w/v) phosphoric acid solution with a mass ratio of 3:2 and activation temperature at 500 degrees C for 60 min with the rate of achieving the activation temperature equal to 10 degrees C min(-1). The cotton stalk activated carbon (CSAC) prepared at these conditions have 1.43 mmol g(-1) acidic surface groups and 1570 m(2) g(-1) BET surface area. Adsorption isotherms for lead(II) on the adsorbents were measured by conducting a series of batch adsorption experiments. The Langmuir maximum adsorption amount of lead(II) on CSAC was more than 119 mg g(-1), which was superior to the ordinary commercial activated carbon (CAC) on the market. Compared with the CAC, the CSAC had a wider applicable pH range from 3.5 to 6.5 for lead(II) uptake. The final pH values at equilibrium after adsorption were lower than the initial pH value, indicating that the ion-exchange process was involved in the adsorption. This is also confirmed by the result that the increase of acidic surface groups favored the adsorption process. Thermodynamic study indicated that the adsorption was a spontaneous and endothermic process. PMID:20542631

Li, Kunquan; Zheng, Zheng; Li, Ye

2010-05-13

19

Determination of traces of chloride and fluoride in H2SO4, H3PO4 and H3BO3 by in situ analyte distillation-ion chromatography.  

PubMed

A simple dual vessel in situ analyte distillation (IAD) system has been developed for suppressed ion chromatographic determination of chloride and fluoride ions in complex matrices. In IAD system, water vapours generated from the outer vessel reacts with sulfuric acid generating heat, thus favouring the quantitative distillation of chloride and fluoride within 30 min on water bath temperature (approximately 80 degrees C). The distilled analytes, as their respective acids in water, were directly injected into an ion-chromatograph. This newly developed method has been applied for analysis of trace impurities in H2SO4, H3PO4 and H3BO3. The detection limits for chloride is 8, 80 and 70ppb (w/w) for H2SO4, H3PO4 and H3BO3, respectively. For fluoride the detection limits are 6 and 60 ppb (w/w) for H2SO4 and H3PO4, respectively. The recovery of spikes for both the analytes ranged between 87 and 100%. PMID:15941060

Thangavel, S; Dash, K; Dhavile, S M; Chaurasia, S C; Mukherjee, T

2005-05-13

20

Preparation and surface characterization of activated carbons from Euphorbia rigida by chemical activation with ZnCl2, K2CO3, NaOH and H3PO4  

NASA Astrophysics Data System (ADS)

Preparation of activated carbons from Euphorbia rigida by chemical activation with different impregnation agents and ratios was studied. ZnCl2, K2CO3, NaOH and H3PO4 were used as chemical activation agents and four impregnation ratios (25-50-75-100%) by mass were applied on biomass. Activation is applied to impregnated biomass samples at 700 °C under sweeping gas in a fixed bed reactor. For determination of chemical and physical properties of the obtained activated carbons; elemental analysis was applied to determine the elemental composition (C, H, N, O) and FT-IR spectra was used to analyze the functional groups. BET equation was used to calculate the surface areas of activated carbons. For understanding the changes in the surface structure, activated carbons were conducted to Scanning Electron Microscopy (SEM). Maximum BET surface area (2613 m2/g) was reached with 75% K2CO3 impregnated biomass sample. Experimental results showed that impregnation types and ratios have a significant effect on the pore structure of activated carbon and E. rigida seems to be an alternative precursor for commercial activated carbon production.

K?l?ç, Murat; Apayd?n-Varol, Esin; Pütün, Ay?e Eren

2012-11-01

21

Bibliographies of Industrial Interest: Thermodynamic Measurements on the Systems CO2-H2O, CuCl2-H2O, H2SO4-H2O, NH3-H2O, H2S-H2O, ZnCl2-H2O, and H3PO4-H2O.  

National Technical Information Service (NTIS)

Contained herein are bibliographies of sources of experimental and correlated thermodynamic data for seven binary aqueous mixtures of industrial importance, namely mixtures of CO2, H2S, NH3, H2SO4, H3PO4, CuCl2 and ZnCl2 with water. The categories of equi...

B. R. Staples D. Garvin D. Smith-Magowan T. L. Jobe J. Crenca

1986-01-01

22

THE DISSOLUTION RATE OF Ca(OH)2 IN AQUEOUS SOLUTIONS  

Microsoft Academic Search

The dissolution rate of reagent grade Ca(OH)2 in aqueous solutions has been determined by means of a spinning disc method. The dissolution rate was found to be independent of disc velocity at a disc Reynold's Number above 9×l0. The dissolution rate is important for environmental applications such as flue gas desulfurization using Ca(OH)2 in wet scrubbers and spray dryer reactors,

JUN WANG; TIM C. KEENER; GUANG LI; SOON-JAI KHANG

1998-01-01

23

SO 2 reaction with Ca(OH) 2 at medium temperatures (300–425°C)  

Microsoft Academic Search

The study of the reaction between Ca(OH)2 and SO2 has been performed in the medium temperature range (300–450°C) under controlled dehydration conditions. The largest SO2 capture has been found at 450°C, 0.64 mol SO2 mol Ca-1, and no influence of the water vapour pressure on the sorbent utilization has been observed. The investigation of the internal porous structure of Ca(OH)2

Ignacio Fernández; Aurora Garea; Angel Irabien

1998-01-01

24

COMPARATIVE SO2 REACTIVITY OF CAO DERIVED FROM CACO3 AND CA(OH)2  

EPA Science Inventory

Experimental data on sulfation rates of CaO particles derived from CaCO3 are compared to those derived from Ca(OH)2 using a product layer diffusion control model differing only in the shape of the CaO grain. Both the model and the experimental data indicate slightly higher reacti...

25

COMPARATIVE SO2 REATIVITY OF CAO DERIVED FROM CACO3 AND CA(OH)2  

EPA Science Inventory

The paper gives results of a Comparison of experimental data on sulfation rates of CaO particles derived from CaC03 with those derived from Ca(OH)2 using a product layer diffusion control model differing only in the shape of the Cao grain. Both the model and the experimental data...

26

Nanostructure and irreversible colloidal behavior of Ca(OH)2: implications in cultural heritage conservation.  

PubMed

Although Ca(OH)2 is one of the oldest art and building material used by mankind, little is known about its nanostructural and colloidal characteristics that play a crucial role in its ultimate performance as a binder in lime mortars and plasters. In particular, it is unknown why hydrated lime putty behaves as an irreversible colloid once dried. Such effect dramatically affects the reactivity and rheology of hydrated lime dispersions. Here we show that the irreversible colloidal behavior of Ca(OH)2 dispersions is the result of an oriented aggregation mechanism triggered by drying. Kinetic stability and particle size distribution analysis of oven-dried slaked lime or commercial dry hydrate dispersions exhibit a significant increase in settling speed and particle (cluster) size in comparison to slaked lime putty that has never been dried. Drying-related particle aggregation also leads to a significant reduction in surface area. Electron microscopy analyses show porous, randomly oriented, micron-sized clusters that are dominant in the dispersions both before and after drying. However, oriented aggregation of the primary Ca(OH)2 nanocrystals (approximately 60 nm in size) is also observed. Oriented aggregation occurs both before and during drying, and although limited before drying, it is extensive during drying. Nanocrystals self-assemble in a crystallographically oriented manner either along the 100 or equivalent 110 directions, or along the Ca(OH)2 basal planes, i.e., along [001]. While random aggregation appears to be reversible, oriented aggregation is not. The strong coherent bonding among oriented nanoparticles prevents disaggregation upon redispersion in water. The observed irreversible colloidal behavior associated with drying of Ca(OH)2 dispersions has important implications in heritage conservation, particularly considering that nowadays hydrated lime is often the preferred alternative to portland cement in architectural heritage conservation. Finally, our study demonstrates that, fortuitously, hydrated lime could be one of the first nanomaterials used by mankind. PMID:16285758

Rodriguez-Navarro, C; Ruiz-Agudo, E; Ortega-Huertas, M; Hansen, E

2005-11-22

27

Effect of electrochemically reactive rust layers on the corrosion of steel in a Ca(OH) 2 solution  

Microsoft Academic Search

Electrochemical and gravimetric measurements are used to study the effect of rust layers on the corrosion of rusted steel in a saturated Ca(OH)2 solution imitating the liquid phase in concrete pores. The results indicate that the reduction of rust is the main cathodic reaction in the first phase of the corrosion process of rusted steel. Subsequently the oxygen reduction reaction

J. A. González; J. M. Miranda; E. Otero; S. Feliu

2007-01-01

28

THE EFFECT OF STORAGE CONDITIONS ON HANDLING AND SO2 REACTIVITY OF CA(OH)2-BASED SORBENTS  

EPA Science Inventory

The article gives results of an investigation of the effect of relative humidity (RH), time, and aeration during calcium hydroxide -- Ca(OH)2--storage for its effect on sorbent handling and reactivity with sulfur dioxide (SO2). nvestigated was the effect of sorbent storage condit...

29

Commercial Ca(OH)2 nanoparticles for the consolidation of immovable works of art  

NASA Astrophysics Data System (ADS)

Calcium hydroxide nanoparticles are effective components for the consolidation treatment of immovable works of art, such as carbonate stone and wall paintings that exhibit both surface and structural degradation. Several formulations have been recently developed, with different characteristics (dispersing solvent, particle size distribution and particle structure), which are expected to result in different long-term consolidating properties. In this contribution, the carbonation of a commercial Ca(OH)2 nanoparticle formulation (Nanorestore®) was characterized through Fourier transform infrared (FTIR) analysis. Nanoparticle films were laid on KBr pellets and stored at room temperature under controlled relative humidity and CO2 pressure. FTIR analysis was used to quantitatively detect the formation of calcium carbonate. Fitting of the experimental data allowed the description of the mechanism of carbonate nucleation and growth. The compatibility of the Nanorestore® formulation for wall painting consolidation was assessed through optical and electron microscopy, colorimetry and water absorption capillarity measurements. The formulation's effectiveness in consolidating powdering painted layers was assessed through application on site and on detached samples of Mesoamerican wall paintings belonging to the pre-Columbian archaeological sites of Ixcaquixtla and Calakmul (Mexico).

Baglioni, P.; Chelazzi, D.; Giorgi, R.; Carretti, E.; Toccafondi, N.; Jaidar, Y.

2013-08-01

30

Dissolution and Carbonation of Portlandite [Ca(OH)2] Single Crystals.  

PubMed

The dissolution and carbonation of portlandite (Ca(OH)2) single crystals was studied by a combination of in situ Atomic Force Microscopy, Scanning Electron Microscopy, and two-dimensional X-ray diffraction. The dissolution of portlandite {0001} surfaces in water proceeds by the formation and expansion of pseudohexagonal etch pits, with edges parallel to ?100? directions. Etch pits on {010} surfaces are elongated along ?001?, with edges parallel to ?101?. The interaction between carbonate-bearing solutions and portlandite results in the dissolution of the substrate coupled with the precipitation of thick islands of CaCO3 that appear oriented on the portlandite substrate. Ex situ carbonation of portlandite in contact with air results in the formation of pseudomorphs that fully preserve the external shape of the original portlandite single crystals. Our observations suggest that portlandite carbonation in contact with air and carbonate-bearing solutions occurs by a similar mechanism, i.e. coupled dissolution-precipitation. Calcite grows epitaxially on {0001} portlandite surfaces with the following orientation: ?001?Cc? ?001?Port. Apparently, no porosity is generated during the reaction, which progresses through the formation of fractures. Our results are of relevance to many processes in which the carbonation of portlandite takes place, such as CO2 capture and storage or the carbonation of cementitious materials. PMID:23915181

Ruiz-Agudo, Encarnación; Kud?acz, Krzysztof; Putnis, Christine V; Putnis, Andrew; Rodriguez-Navarro, Carlos

2013-09-11

31

Odor Control in Evaporation Ponds Treating Olive Mill Wastewater Through the Use of Ca(OH)2  

Microsoft Academic Search

Different amounts of Ca(OH)2 were added in 2 L beakers containing 1 L of olive mill wastewater (OMW). The mixture was stirred for 45 min and left to settle. Wastewater analysis was used in order to determine the effect of the different amounts of calcium hydroxide in the treating process, three days after the application. The Odor Detection Threshold was used for determining

E. Lagoudianaki; T. Manios; M. Geniatakis; N. Frantzeskaki; V. Manios

2003-01-01

32

Odor control in evaporation ponds treating olive mill wastewater through the use of Ca(OH)2.  

PubMed

Different amounts of Ca(OH)2 were added in 2 L beakers containing 1 L of olive mill wastewater (OMW). The mixture was stirred for 45 min and left to settle. Wastewater analysis was used in order to determine the effect of the different amounts of calcium hydroxide in the treating process, three days after the application. The Odor Detection Threshold was used for determining the effect of the treatment in the odors produced in the beakers, three and 30 days after. Both sets of measurements indicated an important reduction in wastewater pollutants and odor emission when 10 g/L of Ca(OH)2 were added. In order to evaluate these results in more realistic conditions. 10 L plastic containers were filled with 6 L of OMW, relevant amounts of Ca(OH)2 were added, the mixture was stirred manually and left to settle in the open. Again, 10 g/L of calcium hydroxide produced the best results in odor reduction and wastewater treatment. PMID:14533921

Lagoudianaki, E; Manios, T; Geniatakis, M; Frantzeskaki, N; Manios, V

2003-01-01

33

Efficient production of D-(-)-lactic acid from broken rice by Lactobacillus delbrueckii using Ca(OH)2 as a neutralizing agent.  

PubMed

Effects of Ca(OH)(2), NH(4)OH, and NaOH as neutralizing agents for efficient recovery of lactic acid was investigated. Lactic acid was produced from broken rice in a simultaneous saccharification and fermentation (SSF) process with Lactobacillus delbrueckii. Consumption of glucose (from broken rice) by the cells and the cell growth were the best with Ca(OH)(2) among the three neutralizing agents used. Maximum productivities of lactic acid reached with Ca(OH)(2), NH(4)OH, and NaOH were 3.59 g l(-1) h(-1), 1.51 g 1(-1) h(-1), and 1.40 g l(-1) h(-1), respectively. Ca(OH)(2) reduced the lactate molarity of the fermentation broth, and thus resulted in the highest lactic acid productivity. Furthermore, it was apparently clear that divalent cation (Ca(2+)) was more effective in neutralizing the cultures compared to monovalent (Na(+) and NH(3)(+)) cations. PMID:22093977

Nakano, Shinta; Ugwu, Charles U; Tokiwa, Yutaka

2011-10-28

34

The protective efficiency of galvanizing against corrosion of steel in mortar and in Ca(OH) 2 saturated solutions containing chlorides  

Microsoft Academic Search

The behaviour of galvanized steel in Ca(OH)2 saturated solutions containing either no additives, chloride or chloride plus nitrite has been studied. The behaviour of galvanized steel in mortar specimens containing the same types of additives has been simultaneously analysed. The results show that the critical chloride threshold for galvanized steel is higher than that for bare steel before the transition

E. Ramirez; J. A. González; A. Bautista

1996-01-01

35

Calcite precipitation from CO2 H2O Ca(OH)2 slurry under high pressure of CO2  

NASA Astrophysics Data System (ADS)

The formation of solid calcium carbonate (CaCO3) from aqueous solutions or slurries containing calcium and carbon dioxide (CO2) is a complex process of considerable importance in the ecological, geochemical and biological areas. Moreover, the demand for powdered CaCO3 has recently increased considerably in various fields of industry. The aim of this study was therefore to synthesize fine particles of calcite with controlled morphology by hydrothermal carbonation of calcium hydroxide at high CO2 pressure (initialP=55bar) and at moderate and high temperatures (30 and 90 °C). The morphology of precipitated particles was identified by transmission electron microscopy (TEM/EDS) and scanning electron microscopy (SEM/EDS). In addition, an X-ray diffraction analysis was performed to investigate the carbonation efficiency and purity of the solid product. Carbonation of dispersed calcium hydroxide (Ca(OH)2(s)+CO2(aq)?CaCO3(s)+H2O) in the presence of supercritical (PT=90 bar, T=90 °C) or gaseous (PT=55 bar, T=30 °C) CO2 led to the precipitation of sub-micrometric isolated particles (<1 ?m) and micrometric agglomerates (<5 ?m) of calcite. For this study, the carbonation efficiency (Ca(OH)2 CaCO3 conversion) was not significantly affected by pressure temperature (PT) conditions after 24 h of reaction. In contrast, the initial rate of calcium carbonate precipitation increased from 4.3 mol/h in the “90 bar 90 °C” system to 15.9 mol/h in the “55 bar 30 °C” system. The use of high CO2 pressure may therefore be desirable for increasing the production rate of CaCO3, carbonation efficiency and purity, to approximately 48 kg/m3 h, 95% and 96.3%, respectively, in this study. The dissipated heat for this exothermic reaction was estimated by calorimetry to be -32 kJ/mol in the “90 bar 90 °C” system and -42 kJ/mol in the “55 bar 30 °C” system.

Montes-Hernandez, G.; Renard, F.; Geoffroy, N.; Charlet, L.; Pironon, J.

2007-10-01

36

Antifungal coatings based on Ca(OH)2 mixed with ZnO/TiO2 nanomaterials for protection of limestone monuments.  

PubMed

The presence and deteriorating action of microbial biofilms on historic stone buildings have received considerable attention in the past few years. Among microorganisms, fungi are one of the most damaging groups. In the present work, antimicrobial surfaces were prepared using suspensions of Ca(OH)2 particles, mixed with ZnO or TiO2 nanoparticles. The antimicrobial surfaces were evaluated for their antifungal activity both in the dark and under simulated natural photoperiod cycles, using Penicillium oxalicum and Aspergillus niger as model organisms, and two limestone lithotypes commonly used in construction and as materials for the restoration of historic buildings. Both Ca(OH)2-ZnO and Ca(OH)2-TiO2 materials displayed antifungal activity: ZnO-based systems had the best antifungal properties, being effective both in the dark and under illumination. In contrast, TiO2-based coatings showed antifungal activity only under photoperiod conditions. Controls with coatings consisting of only Ca(OH)2 were readily colonized by both fungi. The antifungal activity was monitored by direct observation with microscope, X-ray diffraction (XRD), and scanning electron microscopy (SEM), and was found to be different for the two lithotypes, suggesting that the mineral grain distribution and porosity played a role in the activity. XRD was used to investigate the formation of biominerals as indicator of the fungal attack of the limestone materials, while SEM illustrated the influence of porosity of both the limestone material and the coatings on the fungal penetration into the limestone. The coated nanosystems based on Ca(OH)2-50%ZnO and pure zincite nanoparticulate films have promising performance on low porosity limestone, showing good antifungal properties against P. oxalicum and A. niger under simulated photoperiod conditions. PMID:23347459

Gómez-Ortíz, Nikte; De la Rosa-García, Susana; González-Gómez, William; Soria-Castro, Montserrat; Quintana, Patricia; Oskam, Gerko; Ortega-Morales, Benjamin

2013-02-19

37

Characterization of mesoporous carbon prepared from date stems by H3PO4 chemical activation  

NASA Astrophysics Data System (ADS)

The present work was focused on the determination of texture, morphology, crystanillity and oxygenated surface groups characteristics of an activated carbon prepared from date stems. Chemical activation of this precursor at different temperatures (450, 550 and 650 °C) was adopted using phosphoric acid as dehydrating agent at (2/1) impregnation ratio. Fourier transform infrared spectroscopy study was carried out to identify surface groups in date stems activated carbons. The microscopic structure was examined by nitrogen adsorption at 77 K. The interlayer spacing (d200 and d100), stack height (Lc), stack width (La) and effective dimension L of the turbostratic crystallites (microcrystallite) in the date stems activated carbons were estimated from X-ray diffraction data (XRD). Results yielded a surface area, SBET, and total pore volume of 682, 1455, 1319 m2/g and 0,343, 1,045 and 0.735 cm3/g, for the carbon prepared at 450, 550 and 650 °C, respectively. Scanning electron microscopy exhibits a highly developed porosity which is in good agreement with the porous texture derived from gas adsorption data and these results confirm that the activated carbon is dominated by network of slit-shaped mesopores morphology and in some cases by varied micropores morphologies.

Hadoun, H.; Sadaoui, Z.; Souami, N.; Sahel, D.; Toumert, I.

2013-09-01

38

Preparation and characterization of calcium hydroxyapatite and balloon-like calcium phosphate particles from forced hydrolysis of Ca(OH) 2–triphosphate solution  

Microsoft Academic Search

Calcium phosphate particles were prepared by aging a solution of dissolved Ca(OH)2 and sodium triphosphate (sodium tripolyphosphate, Natpp: Na5P3O10) at 100–150°C for 18h in a Teflon-lined screw-capped Pyrex test tube. Large spherical and\\/or small aggregated spherical particles were precipitated with an extremely fast rate of reaction under 100°C. The large spherical particles were amorphous and the small aggregated ones were

Kazuhiko Kandori; Kazuma Takeguchi; Masao Fukusumi; Yoshiaki Morisada

2009-01-01

39

Short-term effects of Ca(OH) 2 additions on phytoplankton biomass: A comparison of laboratory and in situ experiments  

Microsoft Academic Search

To identify mechanisms by which Ca(OH)2 additions reduce phytoplankton biomass in the short term (<20 d), we investigated changes in concentrations of chlorophyll a (chl a), total phosphorus (TP) and calcium (Ca), and pH and turbidity in four eutrophic hardwater lakes, two dugouts and limnocorrals. We also tested the potential effects of high pH and turbidity on biomass of three

Y. Zhang; E. E. Prepas

1996-01-01

40

Enhancement of anaerobic treatability of olive oil mill effluents by addition of Ca(OH)2 and bentonite without intermediate solid/liquid separation.  

PubMed

Previous work on the anaerobic treatment of olive oil mill effluents (OME) have shown: (a) lipids, even if more easily degraded than phenols, were potentially capable of inhibiting methanogenesis more strongly; (b) a pretreatment based on addition of Ca(OH)2 and bentonite removed lipids almost quantitatively; (c) preliminary biotreatability tests performed on the pretreated OME showed high bioconversion into methane at very low dilutions ratios, especially when the mixture (OME, Ca(OH)2 and bentonite) was fed to the biological treatment without providing an intermediate phase separation. This paper was directed towards two main aims: (a) to optimize pretreatment: the best results in terms of methane production were obtained by addition of Ca(OH)2 up to pH 6.5 and of 10 g L-1 of bentonite; (b) to evaluate the enhancement of anaerobic treatability of OME pretreated under optimized conditions in a lab-scale continuous methanogenic reactor fed with the substrate without intermediate solid/liquid separation: very satisfactory performances were obtained (at an organic load of 8.2 kg COD m-3 d-1 and at a dilution ratio of 1:1.5 total COD removal was 91%, biogas production was 0.80 g CH4 (as COD)/g tot. COD, lipids removal was 98%, phenols removal was 63%). The results confirm the double role played by bentonite (adsorption of the inhibiting substances and release of the adsorbed biodegradable matter in the methanogenic reactor). PMID:11443973

Beccari, M; Majone, M; Papini, M P; Torrisi, L

2001-01-01

41

Efficacy of a sustained-release device containing chlorhexidine and Ca(OH)2 in preventing secondary infection of dentinal tubules.  

PubMed

This study was conducted to evaluate the efficacy of the antibacterial activity of Ca(OH)2 and a sustained-release device containing chlorhexidine (SRD) in both sterilization and prevention of secondary infection of the root canal system. Bovine root dentine specimens previously incubated with Streptococcus faecalis were used in this experiment. Two different formulations of the SRD (differing in their cross-linkage), Ca(OH)2 and normal saline (control) were evaluated. The degree of bacterial infection of the root canal was tested after incubation periods of 24 h, 72 h and 7 days with these medicaments. Their efficacy in preventing secondary infection after recontamination was tested after 72 h and 7 days. The results demonstrated that both formulations of the SRD significantly reduced the bacterial population in the primary infected groups, as well as preventing secondary infection of the dentinal tubules in the recontaminated group. By contrast, Ca(OH)2 did not show any antibacterial activity, and failed to sterilize the dentinal tubules or prevent secondary infection after recontamination at the time periods examined. PMID:1399050

Heling, I; Steinberg, D; Kenig, S; Gavrilovich, I; Sela, M N; Friedman, M

1992-01-01

42

134Cs uptake by four plant species and Cs–K relations in the soil–plant system as affected by Ca(OH) 2 application to an acid soil  

Microsoft Academic Search

Three rates of Ca(OH)2 were applied to an acid soil and the 134Cs uptake by radish, cucumber, soybean and sunflower plants was studied. The 134Cs concentration in all plant species was reduced from 1.6-fold in the sunflower seeds to 6-fold in the soybean vegetative parts at the higher Ca(OH)2 rate. Potassium (K) concentration in plants was also reduced, but less

I. Massas; V. Skarlou; C. Haidouti; F. Giannakopoulou

2010-01-01

43

Synthesis, characterization, and electrochemical application of Ca(OH)2-, Co(OH)2-, and Y(OH)3-Coated Ni(OH)2 tubes.  

PubMed

We report on the synthesis, characterization, and electrochemical application of Ca(OH)2-, Co(OH)2-, and Y(OH)3-coated Ni(OH)2 tubes with mesoscale dimensions. These composite tubes were prepared via a two-step chemical precipitation within an anodic alumina membrane under ambient conditions. The morphology and structure of the as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) equipped with energy dispersive spectroscopy (EDS). The results showed that the size of the tubes was of mesoscale dimension and the proportion of the tube morphology was about 95%. The as-prepared composite tubes were further investigated as the positive-electrode materials of rechargeable alkaline batteries. Electrochemical measurements revealed that the Ni(OH)2 tubes coated with Ca(OH)2, Co(OH)2, and Y(OH)3 exhibited superior electrode properties including high discharge capacity, excellent high-temperature and high-rate discharge ability, and good cycling reversibility. The mechanism analysis suggests that both the coated layers and the unique hollow-tube structures play an indispensable role in optimizing the electrochemical performance of nickel hydroxide electrodes. PMID:16852761

Li, Weiyang; Zhang, Shaoyan; Chen, Jun

2005-07-28

44

Thermodynamics of mixing of liquids in the system Ca 3(PO 4) 2?CaCl 2?CaF 2?Ca(OH) 2  

NASA Astrophysics Data System (ADS)

Molten calcium halide and hydroxide salts may be used as flux and reactants in determining apatite exchange equilibria and solid solution behavior. New experimental data and published phase equilibria are used to determine a thermodynamic model of melts and solids along the binary joins of the anhydrous apatite system Ca 3(PO 4) 2?CaCl 2?CaF 2?Ca(OH) 2. In this model, melt components are expressed as Ca0.5X, where X is hydroxide or a halogen, or as Ca 1.5PO 4. The derived binary interaction parameters ( WG' s) are sufficient to describe deviations from Raoultian behavior for the data. Standard state data are derived for molten Ca(OH) 2 and Ca 3(PO 4) 2, and for the intermediate compounds CaClF, CaClOH, and Ca 2PO 4Cl. Melts in the CaCl 2?CaF 2 system show ideal mixing behavior, while the calcium hydroxide-bearing molten salts form asymmetric regular solutions. The hydroxide-bearing melts show the small positive enthalpies of mixing typical for mixed-anion salts. Similar behavior is measured in simpler molten salt mixtures. The positive deviations from Raoultian behavior are not a mathematical artifact of the model. Data are less extensive for the salt-phosphate systems but cover the essential portions of the systems where salt to phosphate ratios are high. The mixtures of the molten salts and phosphates salts show large negative enthalpy interaction parameters ( WH), as is expected in eutectic systems which mix a high-melting-point crystal with a low-melting-point flux. Adequate reproduction of the data requires that some entropy interaction parameters be negative, although small. This implies the presence of ordering in the melt, which is manifested in more polymerized phosphate liquids and glasses as halogenated and hydroxylated orthophosphate and pyrophosphate species. Results of the model indicate that the quaternary system is a good choice for determination of activity-composition relations for the apatites. Comparison of common sources of standard state thermodynamic data ( ROBIE et al., 1979; JANAF, CHASE et al., 1985; CODATA, GARVIN et al., 1987) shows that the data for the salts are very similar where they are not identical. At temperatures below 900°C in the ternary systems, liquid compositions will be on or near the apatite-crystalline salt cotectics, and dissolve less than 1 mol% Ca 3(PO 4) 2. This makes CaCl 2?CaF 2 mixtures excellent candidates for determination of unambiguous apatite activity-compositional relations. Only the Ca(OH) 2 liquidus is strongly affected by the addition of phosphate, but this effect is closely described by a regular solution model.

Tacker, R. C.; Stormer, J. C., Jr.

1993-10-01

45

H 3 PO 4 - and H 2 SO 4 -treated niobic acid as heterogeneous catalyst for methyl ester production  

Microsoft Academic Search

The activity of solid niobic acid treated with sulfuric acid and with phosphoric acid was tested in the catalytic esterification\\u000a of oleic acid and in transesterification of soybean oil with methanol. X-ray diffraction studies revealed niobic acid treated\\u000a with sulfuric acid to be an amorphous solid, while niobic acid treated with phosphoric acid presented a crystalline phase,\\u000a probably due to

Mendelssolm K. de Pietre; Luiz C. P. Almeida; Richard Landers; Rita C. G. Vinhas; Fernando J. Luna

2010-01-01

46

Mechanism of large oscillations of anodic potential during anodization of silicon in H 3PO 4\\/HF solutions  

Microsoft Academic Search

Effect of large oscillations of electrical potential during anodic polarization of silicon in electrolytes composed of phosphoric and hydrofluoric acids has been reported. The oscillations last hours without damping if experimental conditions are optimal. Changes of temperature, anodic current density, intensity of stirring, etc. quench them or convert into less periodic ones. The oscillations are of very high amplitude (typically

V Parkhutik; E Matveeva; R Perez; J Alamo; D Beltrán

2000-01-01

47

Preparation and Characterization of Titanium Dioxide (TiO2) from Sludge produced by TiCl4 Flocculation with FeCl3, Al2(SO4)3 and Ca(OH)2 Coagulant Aids in Wastewater  

Microsoft Academic Search

In this study, TiCl4 coagulant together with coagulant aids such as FeCl3, Al2(SO4)3, and Ca(OH)2 were investigated to improve the photoactivity of titanium dioxide (TiO2) produced from sludge and to increase the resulting low pH value. After TiCl4 flocculation with three coagulant aids, the settled floc (sludge) was incinerated at 600°C to produce TiO2 doped with Fe, Al, and Ca

H. K. Shon; S. Vigneswaran; J. Kandasamy; M. H. Zareie; J. B. Kim; D. L. Cho; J.-H. Kim

2009-01-01

48

Determination of the adsorption capacity of activated carbon made from coffee grounds by chemical activation with ZnCl 2 and H 3PO 4  

Microsoft Academic Search

In order to evaluate the adsorptive capacities of granular activated carbon produced from coffee grounds by chemical activation, the adsorption of different phenols and acid and basic dyes, has been carried out. The comparison with a commercial activated carbon has been made. Adsorption isotherms of phenols and dyes (acid and basic) onto produced and commercial granular activated carbons were experimentally

A. Namane; A. Mekarzia; K. Benrachedi; N. Belhaneche-Bensemra; A. Hellal

2005-01-01

49

Determination of the adsorption capacity of activated carbon made from coffee grounds by chemical activation with ZnCl2 and H3PO4.  

PubMed

In order to evaluate the adsorptive capacities of granular activated carbon produced from coffee grounds by chemical activation, the adsorption of different phenols and acid and basic dyes, has been carried out. The comparison with a commercial activated carbon has been made. Adsorption isotherms of phenols and dyes (acid and basic) onto produced and commercial granular activated carbons were experimentally determined by batch tests. Both Freundlich and Langmuir models are well suited to fit the adsorption isotherm data. As a result, the coffee grounds based activated carbon may be promising for phenol and dye removal from aqueous streams. PMID:15752865

Namane, A; Mekarzia, A; Benrachedi, K; Belhaneche-Bensemra, N; Hellal, A

2005-03-17

50

Carbons prepared from coffee grounds by H 3PO 4 activation: Characterization and adsorption of methylene blue and Nylosan Red N-2RBL  

Microsoft Academic Search

Activated carbons were prepared by the pyrolysis of coffee grounds impregnated by phosphoric acid at 450°C for different impregnation ratios: 30, 60, 120 and 180wt.%. Materials were characterized for their surface chemistry by elemental analysis, “Boehm titrations”, point of zero charge measurements, Infrared spectroscopy, thermogravimetric analysis (TGA); as well as for their porous and morphological structure by Scanning Electron Microscopy

A. Reffas; V. Bernardet; B. David; L. Reinert; M. Bencheikh Lehocine; M. Dubois; N. Batisse; L. Duclaux

2010-01-01

51

Corrosion behaviour of micro-plasma arc welded stainless steels in H 3PO 4 under flowing conditions at different temperatures  

Microsoft Academic Search

This paper studies the general corrosion behaviour of the micro-plasma arc welded AISI 316L stainless steel in phosphoric acid at different temperatures (25–60°C) and at a Reynolds number of 1456. Galvanic corrosion has been studied using zero-resistance ammeter (ZRA) measurements and polarization curves (by the mixed potential theory). Results show that the microstructure of the stainless steel is modified due

R. Sánchez-Tovar; M. T. Montañés; J. García-Antón; A. Guenbour; A. Ben-Bachir

2011-01-01

52

Supercapacitor Behavior with KCl Electrolyte  

Microsoft Academic Search

Amorphous MnO2·nH2O in a mild 2 M KCl aqueous electrolyte proves to be an excellent electrode for a faradaic electrochemical capacitor cycled between ?0.2 and +1.0 V versus SCE. In this potential range, it had ideal behavior with a specific capacitance ofca. 200 F\\/g, excellent cyclability at 2 mA\\/cm2over 100 cycles, and a short-circuit initial current density of 0.23 A\\/cm2with

Hee Y. Lee; J. B. Goodenough

1999-01-01

53

Boron removal and recovery from concentrated wastewater using a microwave hydrothermal method  

Microsoft Academic Search

Boron compounds are widely-used raw materials in industries. However, elevated boron concentrations in aqueous systems may be harmful to human and plants. In this study, calcium hydroxide (Ca(OH)2) alone and Ca(OH)2 with phosphoric acid (H3PO4) addition (P-addition) were used to remove and recover boron from wastewater using hydrothermal methods. A microwave (MW) hydrothermal method was used and compared with the

Hao-Cheng Tsai; Shang-Lien Lo

2011-01-01

54

Effect of mixing ratio and pH on the reaction between Ca4(PO4)2O and CaHPO4.  

PubMed

The reaction of Ca(PO4)2O (TTCP) and CaHPO4 (DCPA) in an aqueous solution has been shown to be responsible for the hardening of a calcium phosphate cement. This reaction was investigated by monitoring pH changes and composition of solid phases. In the first set of experiments (no attempt to control pH), 2.5 g each of mixtures of TTCP/DCPA, molar ratio from 0.25 to 2, was placed in 12.5 mL of 0.15 mol/L KCl solution, at initial pH about 7, and the pH was allowed to drift for 24 h. Results show that at any time up to 24 h, the pHs were higher for slurries with higher TTCP/DCPA molar ratios. For the slurries with TTCP/DCPA molar ratio of >/= 0.83, the 24 h pHs of the slurries were 9 to 11, whereas for those with TTCP/DCPA of KCl solution. The pH values were kept constant (6, 8 or 10) by using H3PO4 and \\Ca(OH)2 or HCl and KOH as titrant solutions. At pH 8, DCPA and TTCP dissolved at about the same rate, whereas at pH 10, DCPA was consumed more rapidly than TTCP. At both pHs, OHAp was the only product formed. However, at pH 6, the composition of reaction products depended on the types of the titrants used. Specifically when H3PO4 and Ca(OH)2 were used, hydrolysis of TTCP was the predominant reaction and both octacalcium phosphate and OHAp were formed. But, when HCl and KOH were used, only OHAp was formed. In this case hydrolysis of TTCP and DCPA appeared to proceed independently with TTCP hydrolysis beginning immediately and progressing slowly through 48 h while the DCPA hydrolysis began several hours after the reaction started but was completed in 24 h. PMID:15348028

Matsuya, S; Takagi, S; Chow, L C

2000-05-01

55

Laser characteristics of KCL:O2(-)  

NASA Astrophysics Data System (ADS)

Amplified spontaneous emission and laser action have been observed at 77 K in KCl crystals containing the superoxide ion (O2/-/). The laser operates in two bands of width approximately 50 A centered at 6350 A and 5984 A. These bands are the (lattice) phonon sidebands of vibronic transitions of the superoxide ion. At lower temperatures (approximately 6 K) amplified spontaneous emission is observed in the zero phonon line at 6294 A.

Wilk, S. R.; Boyd, R. W.; Teegarden, K. J.

1983-10-01

56

Activity coefficients of KCl in highly concentrated protein solutions  

Microsoft Academic Search

As a contribution to the understanding of the thermodynamic state of single salts in living systems, the activity coefficients of KCl were determined in concentrated bovine serum albumin (BSA) solutions. The concentration range studied was 0.01 to 0.5 M KCl and zero to 18% wt BSA, thus amply covering physiological conditions. The activity coefficients of the salt were measured using

P. Ocon; C. Acerete; M. D. Reboiras

1987-01-01

57

KCl stimulation increases norepinephrine transporter function in PC12 cells.  

PubMed

The norepinephrine transporter (NET) plays a pivotal role in terminating noradrenergic signaling and conserving norepinephrine (NE) through the process of re-uptake. Recent evidence suggests a close association between NE release and regulation of NET function. The present study evaluated the relationship between release and uptake, and the cellular mechanisms that govern these processes. KCl stimulation of PC12 cells robustly increased [3H]NE uptake via the NET and simultaneously increased [3H]NE release. KCl-stimulated increases in uptake and release were dependent on Ca2+. Treatment of cells with phorbol-12-myristate-13-acetate (PMA) or okadaic acid decreased [3H]NE uptake but did not block KCl-stimulated increases in [3H]NE uptake. In contrast, PMA increased [3H]NE release and augmented KCl-stimulated release, while okadaic acid had no effects on release. Inhibition of Ca2+-activated signaling cascades with KN93 (a Ca2+ calmodulin-dependent kinase inhibitor), or ML7 and ML9 (myosin light chain kinase inhibitors), reduced [3H]NE uptake and blocked KCl-stimulated increases in uptake. In contrast, KN93, ML7 and ML9 had no effect on KCl-stimulated [3H]NE release. KCl-stimulated increases in [3H]NE uptake were independent of transporter trafficking to the plasma membrane. While increases in both NE release and uptake mediated by KCl stimulation require Ca2+, different intracellular mechanisms mediate these two events. PMID:16879714

Mandela, Prashant; Ordway, Gregory A

2006-07-31

58

Sorption of Radioactive Iodine and Fluoride Ion on Hydroxyapatite from the Aqueous Phase  

Microsoft Academic Search

Sorption of the 131I-, 131IO3-, and F- ions on various samples of hydroxyapatite (HAP) from aqueous solutions was studied. The HAP samples were prepared by the following reactions: Ca(OH)2 + H3PO4 ? HAP?, CACl2 + Na3PO4 + NaOH ? HAP?, and Ca(NO3)2 + HAP seed + (NH4)2HPO4 + NH3 ? HAP?. None of the HAP samples sorb ionic species of

S. A. Kulyukhin; E. P. Krasavina; L. V. Mizina; V. B. Krapukhin; V. V. Kulemin; I. A. Rumer; N. V. Tanashchuk

2004-01-01

59

Equations of state for solid NaCl-KCl and liquid NaCl-KCl-H(sub 2)O.  

National Technical Information Service (NTIS)

The equilibrium between the solid solution of NaCl-KCl and the ternary liquid NaCl-KCl-H(sub 2)O is both scientifically interesting and geologically important. Equations of the Margules type have been derived for the two phases that accurately reproduce t...

K. S. Pitzer S. M. Sterner

1991-01-01

60

Composition gradients in electrolyzed LiCl-KCl eutectic melts  

NASA Astrophysics Data System (ADS)

Analysis of transport in a mixed electrolyte has previously predicted significant composition gradients in the LiCl-KCl electrolyte of high temperature LiS/ batteries. Composition gradients in quenched electrolyzed LiCl-KCl eutectic contained in yttria felt are measured with high distance resolution by scanning electron microscopy with energy dispersive X-ray spectroscopy. The reported results include composition profiles of LiCl-KCl coontained in porous Y2O3 and electrolyzed in three cells, two with solid Li-Al electrodes and one with a porous Li-Al anode.

Vallet, C. E.; Heatherly, D. E.; Braunstein, J.

1983-12-01

61

Effect of KCl addition method on the Pt/KL catalyst for the aromatization of hexane  

SciTech Connect

The influence of the method for loading platinum precursor and adding KCl, KCl loading content, calcination temperature, KCl addition procedure, various additives, and water washing on the activity and selectivity of Pt/KL catalysts for hexane reforming reaction has been investigated. The catalyst preparation methods involve ion exchange (IE), incipient wetness impregnation (IWI), and coimpregnation with KCl (IWI-KCl). The Pt/KL catalysts prepared by ion exchange with [Pt(NH[sub 3])[sub 4

Dai, Lian-Xin; Sakashita, Haru; Tatsumi, Takashi (Univ. of Tokyo (Japan))

1994-05-01

62

Separation of Pure LiCl-KCl Eutectic Salt from a Mixture of LiCl-KCl Eutectic Salt and Rare-Earth Precipitates by Vacuum Distillation  

Microsoft Academic Search

In this study, the vacuum distillation of LiCl-KCl eutectic salt in a mixture of LiCl-KCl eutectic salt and rare-earth precipitates was carried out to evaluate the vaporization characteristics of LiCl-KCl eutectic salt. It was confirmed that the required time for salt vaporization was reduced by a reduction in the pressure. It appeared that the vaporization of LiCl-KCl eutectic salt containing

Hee-Chul EUN; Hee-Chul YANG; Yong-Jun CHO; Hwan-Seo PARK; Eung-Ho KIM; In-Tae KIM

2007-01-01

63

F Centers in Additively Colored KCl:NaCl Crystals  

Microsoft Academic Search

Two centers have been investigated which, like the FA center, are produced by optical conversion from F centers in sodium-doped KCl crystals. They each have one absorption band on the long-wavelength side of the F band, and they each contain one F center. One of these, the FB center, absorbs at around 636 nm and luminesces at 1240 nm, while

Irwin Schneider

1969-01-01

64

Phototransferred Thermoluminescence of KCL:Eu2+ Dosemeters  

Microsoft Academic Search

The phototransferred thermoluminescence (PTTL) of KCl:Eu2+ crystals was studied after exposure to X -rays or beta radiation. The main thermoluminescence (TL) peaks were found around 370, 390 and 470 K. The 470 K highest intensity peak is considered to be the dosimetric peak due to its low fading and linear dose behavior. The main dosimetric peak is sharply decreased after

M. Barboza-Flores; R. Meléndrez; V. Chernov; R. Bernal; T. M. Piters; R. Pérez-Salas; R. Aceves; M. Pedroza-Montero; B. Castañeda

2001-01-01

65

Faraday Rotation of the Z1 Center in Kcl.  

National Technical Information Service (NTIS)

Using a 50 kilogauss superconductive magnet, the Faraday Rotation of Z1 centers in KCl crystals doped with Ca(++) and Sr(++) was measured. The spectral dependence of the rotation follows the expectation for a rigid shift model of the Z1 band, with negativ...

F. Luty H. Paus

1968-01-01

66

Study of silver atoms in anionic position in KCL  

NASA Astrophysics Data System (ADS)

The local geometry and electronic distribution of silver atoms trapped in anionic centres (Ag-a(0)) of KCl has been studied by means of Density Functional Theory (DFT) and cluster models involving up to 123 ions. This leads to an important outwards relaxation of the metal-ligand distance of about 13.1% with respect to the pure lattice (RK-Cl =3.14 Angstrom), which plays an important role for understanding experimental EPR data. The higher stability and more localised nature of this centre, compared to Ag-0 at a cationic site (Ag-c(0)), is shown to be related to the energy difference between the Ag(5s) level and the conduction band. The charge distribution in the a(1g) level for Ag-a(0) and Ag-c(0) are compared. These results allow one to understand the different hyperfine constants due to both centres in KCl.

Garcia-Fernandez, P.; Aramburu, J. A.; Barriuso, M. T.; Moreno, M.

67

Phase transformation rate in shock-loaded KCL  

NASA Astrophysics Data System (ADS)

Previous experimental data on shocked single crystal KCl, between 20 and 40 kbar, displayed the B1-->B2 phase transformation. Stress histories at the impact surface provided information on phase change kinetics: very rapid transformation to a non-equilibrium, metastable state followed by a slower transformation to the equilibrium state. In the current study, we analyzed the transmitted wave profiles, which yielded additional insight on the phase transformation kinetics of KCl. Our analyses do not conclusively determine these rates as different methods of analysis give different estimates. It is clear, however, that the transformation rate for [100] crystals was larger than estimated previously. The study also demonstrates that strength effects may play an important role on both the P2 arrival time and on the transient drop in stress observed behind the P1 wave as measured at the rear quartz gauge, and that transformation rate effects may be confounded with strength effects in these experiments behind P1 wave. .

Ding, Jow-Lian; Hayes, Dennis

2000-04-01

68

Thermal Activation Energies in NaCl and KCl Crystals  

Microsoft Academic Search

Thermal activation energies were computed from various glow peaks of NaCl and KCl single crystals. The method developed in the preceding paper has been used successfully in these calculations. Good agreement was obtained with the results calculated from the initial rise of the glow peaks. Activation energies varied from 0.3 to 1.5 ev for various peaks in the glow curve

A. Halperin; A. A. Braner; A. Ben-Zvi; N. Kristianpoller

1960-01-01

69

Positron states in KCL crystals before and after radiation exposure  

NASA Astrophysics Data System (ADS)

The features of positron annihilation in KCl crystals before and after radiation exposure is investigated. A significant increase in the efficiency of the “ortho-vapor” process of positronium state conversion is detected. A model is proposed for taking part in the “ortho-vapor” conversion of conduction electrons drawn into the conduction band by a positron field that affords a qualitative interpretation of the results obtained and permits values of the electron concentration in a spur to be obtained.

Aref'ev, K. P.; Boev, O. V.; Bondarenko, A. L.

1988-07-01

70

Morphological and structural investigation of ?-sexithiophene grown on KCl (100)  

NASA Astrophysics Data System (ADS)

?-sexithiophene was deposited on KCl (100) by hot wall epitaxy technique at different substrate temperatures (60 °C 135 °C). The morphological investigation was performed by AFM and optical microscopy, revealing terraced islands and needle-like anisotropic structures. Structural investigations were performed by specular XRD scans. Upright standing molecules have been detected, which could be related to the terraced islands ((100) crystal contact plane). Furthermore, (010) and (-411) crystal planes have been observed, which explains the observed nano-needles (flat lying molecules). The texture was investigated by XRD pole figures, showing that all three crystal types exhibit a well defined azimuthal alignment with respect to KCl high symmetry directions. Interestingly, the epitaxial orientation of the islands could be explained by ledge directed epitaxy, which describes the nucleation of crystallites on existing topographic features on the substrate (nano-needles). A real space model of the crystallites was developed with the help of XRD pole figures and single crystal data. Surprisingly, the azimuthal orientation of the long moleculear axis is exactly the same for needles with (010) and (-411) contact planes. This observation represents a hint that the adsorption geometry of single molecules seems to be decisive for the organic crystal nucleation. Additionally, the substrate surface symmetry is nicely reflected by the multiplicity of formed needle orientations.

Schwabegger, Günther; Djuric, Tatjana; Sitter, Helmut; Resel, Roland; Simbrunner, Clemens

2013-09-01

71

Ultra low loss coatings of KCl laser windows  

NASA Astrophysics Data System (ADS)

In the last few years, several low optical absorption 10.6 micrometer AR coatings for KCl have been developed at Hughes Research Laboratories (HRL) and at other laboratories. The objective of this program was the development of 9.27 micrometer AR coatings which have a film absorption loss of less than 0.01% and a reflection of less than 0.1% per surface. The achievement of the program objective will permit the development of a 9.27 micrometer AR coating for a 32.5 cm diameter polycrystalline KCl window. Because previous studies had shown that castings deposited under ultra-high vacuum (UHV) conditions had lower absorption losses than did coatings deposited in conventional vacuum systems, the present study was limited to UHV-deposited films. Mass spectrometer analysis had shown that impurities were evolved occasionally during the evaporation of film materials. As a consequence, residual gas analysis (RGA) was performed to ensure that impurities were not present in the system. Also if impurities were located in the film materials, either they were removed by reactive atmosphere processing (RAP) or techniques were developed to prepare clean material.

Zuccaro, D.

1978-03-01

72

Lattice Parameter Method for Determining the Composition of NH4Cl04/KCl04 Solid Solution.  

National Technical Information Service (NTIS)

The lattice parameters of eight samples of NH4ClO4, KClO4, and NH4ClO4/KClO4 solid solutions were determined by photographic powder x-ray diffraction. With the aid of a computer, the parameters were calculated utilizing both least squares analysis and suc...

A. J. Bracuti

1971-01-01

73

Morphological and Structural Investigation of Sexithiophene Growth on KCl (100)  

PubMed Central

The morphology and structure of sexithiophene deposited on KCl (100) substrates was investigated by scanning force microscopy and specular X-ray diffraction measurements. Two different needle-like structures with {010} and {4?11} contact planes have been observed as well as islands of almost upright standing sexithiophene molecules with a {100} contact plane. Furthermore an azimuthal alignment of all three crystal orientations was observed by X-ray diffraction pole figure measurements, and the growth directions reflect the 4-fold rotational symmetry of the substrate surface. In addition the analysis of crystals with {4?11} and {100} contact planes unveiled that they share a common crystallographic direction which is explained by ledge directed epitaxy.

2012-01-01

74

Morphological and Structural Investigation of Sexithiophene Growth on KCl (100).  

PubMed

The morphology and structure of sexithiophene deposited on KCl (100) substrates was investigated by scanning force microscopy and specular X-ray diffraction measurements. Two different needle-like structures with {010} and {4?11} contact planes have been observed as well as islands of almost upright standing sexithiophene molecules with a {100} contact plane. Furthermore an azimuthal alignment of all three crystal orientations was observed by X-ray diffraction pole figure measurements, and the growth directions reflect the 4-fold rotational symmetry of the substrate surface. In addition the analysis of crystals with {4?11} and {100} contact planes unveiled that they share a common crystallographic direction which is explained by ledge directed epitaxy. PMID:23413362

Schwabegger, Günther; Djuric, Tatjana; Sitter, Helmut; Resel, Roland; Simbrunner, Clemens

2012-12-24

75

Phototransferred Thermoluminescence of KCL:Eu2+ Dosemeters  

NASA Astrophysics Data System (ADS)

The phototransferred thermoluminescence (PTTL) of KCl:Eu2+ crystals was studied after exposure to X -rays or ? radiation. The main thermoluminescence (TL) peaks were found around 370, 390 and 470 K. The 470 K highest intensity peak is considered to be the dosimetric peak due to its low fading and linear dose behavior. The main dosimetric peak is sharply decreased after illumination with UV light of a previously irradiated specimen. The PTTL is wavelength dependent and has been shown to peak in the 220 - 230 nm region and 650 nm in previously non irradiated and irradiated samples, respectively. The PTTL spectral response is always a broad band around 390 - 490 nm peaked at 425 nm, which is related to the well-known Eu2+ emission.

Barboza-Flores, M.; Meléndrez, R.; Chernov, V.; Bernal, R.; Piters, T. M.; Pérez-Salas, R.; Aceves, R.; Pedroza-Montero, M.; Castañeda, B.

2001-04-01

76

Concentration and precipitation of NaCl and KCl from salt cake leach solutions by electrodialysis  

SciTech Connect

Electrodialysis was investigated for cost-effective recovery of salt from salt cake leach solutions. (Salt cake is a waste stream generated by the aluminum industry during treatment of aluminum drosses and scrap.) We used a pilot-scale electrodialysis stack of 5 membrane pairs, each with an effective area of 0.02 m{sup 2}. The diluate stream contained synthetic NaCl, KCl,mixtures of NaCl and KCl, and actual salt cake leach solutions (mainly NaCl and KCl, with small amounts of MgCl{sub 2}). We concentrated and precipitated NaCl and KCl salts from the concentrate steam when the initial diluate stream concentration was 21.5 to 28.8 wt% NaCl and KCl. We found that water transferring through the membranes was a significant factor in overall efficiency of salt recovery by electrodialysis.

Sreenivasarao, K; Patsiogiannis, F.; Hryn, J.N.

1997-02-09

77

LETTER TO THE EDITOR: Luminescence from KCl co-doped with Eu2+ and Eu3+ ions  

NASA Astrophysics Data System (ADS)

Distinct holes are found in the blue emission from KCl co-doped with divalent and trivalent europium ions. This extraordinary emission feature is associated with the process of reabsorption from Eu2+ to Eu3+ ions in KCL.

Jun-Gill, Kang; Min-Kook, Nah; Youngku, Sohn

2000-03-01

78

H2O activity in concentrated KCl and KCl-NaCl solutions at high temperatures and pressures measured by the brucite-periclase equilibrium  

NASA Astrophysics Data System (ADS)

H2O activities in supercritical fluids in the system KCl-H2O-(MgO) were measured at pressures of 1, 2, 4, 7, 10 and 15 kbar by numerous reversals of vapor compositions in equilibrium with brucite and periclase. Measurements spanned the range 550-900°C. A change of state of solute KCl occurs as pressures increase above 2kbar, by which H2O activity becomes very low and, at pressures of 4kbar and above, nearly coincident with the square of the mole fraction (xH2O). The effect undoubtedly results primarily from ionic dissociation as H2O density (?H2O) approaches 1gm/cm3, and is more pronounced than in the NaCl-H2O system at the same P-T-X conditions. Six values of solute KCl activity were yielded by terminal points of the isobaric brucite-periclase T-xH2O curves where sylvite saturation occurs. The H2O mole fraction of the isobaric invariant assemblage brucite-periclase-sylvite-fluid is near 0.52 at all pressures, and the corresponding temperatures span only 100°C between 1 and 15kbar. This remarkable convergence of the isobaric equilibrium curves reflects the great influence of pressure on lowering of both KCl and H2O activities. The H2O and KCl activities can be expressed by the formulas: aH2O=?H2O[xH2O+(1+(1+?)xKCl)], and aKCL=?KCl[(1+?)xKCl/(xH2O+(1+?)xKCl)](1+?), where ? is a degree of dissociation parameter which increases from zero at the lowest pressures to near one at high pressures and the ?'s are activity coefficients based on an empirical regular solution parameter W: ln ?i=(1-xi)2W. Least squares fitting of our H2O and KCl activity data evaluates the parameters: ?=exp(4.166 -2.709/?H2O) - 212.1P/T, and W=(-589.6-23.10P) /T, with ?H2O in gm/cm3, P in kbar and T in K. The standard deviation from the measured activities is only +/-0.014. The equations define isobaric liquidus curves, which are in perfect agreement with previous DTA liquidus measurements at 0.5-2kbar, but which depart progressively from their extrapolation to higher pressures because of the pressure-induced dissociation effect. The great similarity of the NaCl-H2O and KCl-H2O systems suggests that H2O activities in the ternary NaCl-KCl-H2O system can be described with reasonable accuracy by assuming proportionality between the binary systems. This assumption was verified by a few reconnaissance measurements at 10kbar of the brucite-periclase equilibrium with a Na/(Na+K) ratio of 0.5 and of the saturation temperature for Na/(Na+K) of 0.35 and 0.50. At that pressure the brucite-periclase curves reach a lowest xH2O of 0.45 and a temperature of 587°C before salt saturation occurs, values considerably lower than in either binary. This double-salt eutectic effect may have a significant application to natural polyionic hypersaline solutions in the deep crust and upper mantle in that higher solute concentrations and very low H2O activities may be realized in complex solutions before salt saturation occurs. Concentrated salt solutions seem, from this standpoint, and also because of high mechanical mobility and alkali-exchanging potential, feasible as metasomatic fluids for a variety of deep-crust and upper mantle processes.

Aranovich, L. Y.; Newton, R. C.

79

Thermodynamic analysis of TiH\\/sub x\\/\\/KClOâ combustion in a closed system  

Microsoft Academic Search

The combustion of TiH\\/sub x\\/\\/KClOâ in a closed system with densities of 50 to 85 percent of the theoretical void free density is investigated. The thermodynamic properties are determined assuming equilibrium conditions using the TIGER computer program. Assuming complete combustion of the TiH\\/sub x\\/\\/KClOâ and a constant volume for the closed system, the calculated results indicate an equilibrium pressure that

A. Razani; M. Shahinpoor

1988-01-01

80

Current-induced composition gradients in molten LiCl-KCl battery electrolytes  

Microsoft Academic Search

Current induced composition gradients were demonstrated in molten LiCl-KCl eutectic mixture, the electrolyte of a LiAl\\/LiCl-KCl\\/FeS\\/sub x\\/ battery. The gradients were produced by electrolysis of the salt between LiAl electrodes at currents of 50-100 mA cm⁻², and quenching. Analysis of composition profiles in quenched samples was by atomic absorption spectroscopy (AA), which gave good precision, and by x-ray fluorescence spectroscopy

J. Braunstein; S. Cantor; C. E. Vallet

1985-01-01

81

Distribution behavior of plutonium and americium in LiCl–KCl eutectic\\/liquid cadmium systems  

Microsoft Academic Search

The thermodynamics of plutonium and americium in LiCl–KCl eutectic\\/liquid cadmium systems was studied with interest in the oxidation state of americium in the salt phase. The standard potential of plutonium vs. the Ag\\/AgCl (1 wt% AgCl) electrode, E0Pu\\/Pu(III), in the LiCl–KCl eutectic was measured in the temperature range of 400–500°C and given by the equation with a standard deviation, ?=0.0009

Y Sakamura; O Shirai; T Iwai; Y Suzuki

2001-01-01

82

Solubility of NaCl and KCl in aqueous HCl from 20 to 85??C  

USGS Publications Warehouse

The solubilities of NaCl and KCl in aqueous HCl solutions were determined from 20 to 85??C at concentrations ranging from 0 to 20 g of HCl/100 g of solution. Equations are given that describe the solubilities over the range of conditions studied. For NaCl and KCl respectively measured solubilities show an average deviation from these equations of ??0.10 and ??0.08 g/100 g of saturated solution.

Potter, II, R. W.; Clynne, M. A.

1980-01-01

83

Proprietes Thermodynamiques du Chlorure D 'argent Dans le Melange Eutectique Fondu Kcl-LiCl (Thermodynamic Properties of Silver Chloride in the Molten Kcl-LiCl Eutectic).  

National Technical Information Service (NTIS)

The e.m.f. of the cell: Ag/AgCl(X).KCl-LiCl(eut)/Cl2/C was measured for mole fractions of between 0.0001 and 1, and for temperatures of between 400 and 500C. From the function E = F (X,T) are deduced: (1) the partial molar entropy of silver chloride; (2) ...

P. Jarny

1966-01-01

84

Calculation of the standard partial molal thermodynamic properties of KCl{sup 0} and activity coefficients of aqueous KCl at temperatures and pressures to 1000{degree}C and 5 kbar  

SciTech Connect

Regression of experimental activity coefficient and dissociation constant data reported in the literature with the Hueckel and Setchenow equations and the revised HKF equations of state generated parameters and thermodynamic properties of dissociated KCl and KCl{sup 0} at 25{degrees}C and bar that can be used to calculate the standard partial molal thermodynamic properties of KCl{sup 0} and the activity coefficients of KCl at temperatures and pressures to 1000{degrees}C and 5 kbar. 46 refs., 6 figs., 4 tabs.

Pokrovskii, V.A. [ETH Zentrum, Zuerich (Switzerland); Helgeson, H.C. [Univ. of California, Berkeley, CA (United States)

1997-06-01

85

Ionic mobility and dielectric relaxation in supercooled liquid KCl-glycerol solutions  

NASA Astrophysics Data System (ADS)

Measurements of the electrical conductivities of liquid and supercooled liquid KCl-glycerol solutions between + 50·6°C and -89·1°C are described. Time domain measurements of dielectric relaxation in pure glycerol between -78·1°C and -91·0°C, and in KCl-glycerol solutions between -77·5°C and -89·1°C are also described. Empirical equations are presented which in each case describe the non-Arrhenius temperature dependence over more than 12 decades in value with a r.m.s. deviation of less than 15 per cent. A 'power law' fit is found to be slightly better than a 'Vogel-Tammann-Fulcher' fit in each case. The temperature dependence of Walden product for KCl-glycerol solutions is discussed, and the relaxation data for pure glycerol is discussed in the light of the Kauzmann paradox.

Champeney, D. C.; Ould Kaddour, F.

86

Preparation and Humidity Sensing Properties of KCl/MCM-41 Composite  

NASA Astrophysics Data System (ADS)

KCl/mobil composition of matter-41 (MCM-41) composite has been synthesized via a heat-treating process and characterized by x-ray diffraction, high resolution transmission electron microscopy, and nitrogen adsorption/desorption isotherms. In contrast with pure MCM-41, KCl/MCM-41 composite exhibits improved humidity sensing properties within the relative humidity range of 11-95%. The impedance of KCl/MCM-41 composite changes by about four orders of magnitude over the whole humidity range with the response time and the recovery times are about 30 s and 35 s, respectively. Small humidity hysteresis and good stability are also observed based on our product. These results make our product a good candidate in fabricating humidity sensors with high performances and low synthetic complexity.

Liu, Li; Kou, Li-Ying; Zhong, Zhi-Cheng; Wang, Lian-Yuan; Liu, Li-Fang; Li, Wei

2010-05-01

87

Density and surface tension of melts in the system NaCl-KCl-UCl/sub 3/  

SciTech Connect

The results of a study of the density and surface tension of melts in the system NaCl-KCl-UCl/sub 3/ is reported over wide ranges of temperature and concentration. Data on densities of melts of equimolar components of the system are available only in the literature. Density and surface tension data for melts of the binary mixtures, NaCl-KCl, NaCl-UCl/sub 3/, and KCl-UCl/sub 3/ are also literature values. Analysis of results shows that mixing of Na, K and uranium chlorides in melts is accompanied by complex formation of the type UCl/sub 5//sup 2 -/, and that their stability is greater than in the binary melts. 9 references, 3 figures, 1 table.

Katyshev, S.F.; Dubinin, B.V.; Desyatnik, V.N.

1983-09-01

88

Thermodynamic re-optimization of the DyCl 3–KCl system  

Microsoft Academic Search

The intermediate compounds, K3DyCl6, K2DyCl5 and KDy2Cl7, in the DyCl3–KCl system, are confirmed by X-ray powder diffraction method. With CALPHAD technology the phase diagram of the DyCl3–KCl system is re-optimized and calculated using ChemSage software. A set of thermodynamic functions has been optimized based on an interactive computer-assisted analysis. The calculated phase diagram and optimized thermodynamic parameters are thermodynamically self-consistent.

Xianran Xing; Shuyu Dai; Zhenqi Zhu; Toshihiro Tanaka

2002-01-01

89

Theoretical and empirical investigations of KCl:Eu{sup 2+} for nearly water-equivalent radiotherapy dosimetry  

SciTech Connect

Purpose: The low effective atomic number, reusability, and other computed radiography-related advantages make europium doped potassium chloride (KCl:Eu{sup 2+}) a promising dosimetry material. The purpose of this study is to model KCl:Eu{sup 2+} point dosimeters with a Monte Carlo (MC) method and, using this model, to investigate the dose responses of two-dimensional (2D) KCl:Eu{sup 2+} storage phosphor films (SPFs). Methods: KCl:Eu{sup 2+} point dosimeters were irradiated using a 6 MV beam at four depths (5-20 cm) for each of five square field sizes (5x5-25x25 cm{sup 2}). The dose measured by KCl:Eu{sup 2+} was compared to that measured by an ionization chamber to obtain the magnitude of energy dependent dose measurement artifact. The measurements were simulated using DOSXYZnrc with phase space files generated by BEAMnrcMP. Simulations were also performed for KCl:Eu{sup 2+} films with thicknesses ranging from 1 {mu}m to 1 mm. The work function of the prototype KCl:Eu{sup 2+} material was determined by comparing the sensitivity of a 150 {mu}m thick KCl:Eu{sup 2+} film to a commercial BaFBr{sub 0.85}I{sub 0.15}:Eu{sup 2+}-based SPF with a known work function. The work function was then used to estimate the sensitivity of a 1 {mu}m thick KCl:Eu{sup 2+} film. Results: The simulated dose responses of prototype KCl:Eu{sup 2+} point dosimeters agree well with measurement data acquired by irradiating the dosimeters in the 6 MV beam with varying field size and depth. Furthermore, simulations with films demonstrate that an ultrathin KCl:Eu{sup 2+} film with thickness of the order of 1 {mu}m would have nearly water-equivalent dose response. The simulation results can be understood using classic cavity theories. Finally, preliminary experiments and theoretical calculations show that ultrathin KCl:Eu{sup 2+} film could provide excellent signal in a 1 cGy dose-to-water irradiation. Conclusions: In conclusion, the authors demonstrate that KCl:Eu{sup 2+}-based dosimeters can be accurately modeled by a MC method and that 2D KCl:Eu{sup 2+} films of the order of 1 {mu}m thick would have minimal energy dependence. The data support the future research and development of a KCl:Eu{sup 2+} storage phosphor-based system for quantitative, high-resolution multidimensional radiation therapy dosimetry.

Zheng Yuanshui; Han Zhaohui; Driewer, Joseph P.; Low, Daniel A.; Li, H. Harold [Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 (United States)

2010-01-15

90

Laser-stimulable transparent KCl:Eu crystals for erasable and rewritable optical memory utilizing photostimulated luminescence  

NASA Astrophysics Data System (ADS)

Intense photostimulated luminescence (PSL) with a peak at 420 nm is observed in ultraviolet (UV)-light-irradiated europium-doped potassium chloride (KCl:Eu) single crystals. The PSL characteristics of UV-irradiated KCl:Eu for optical memory application are studied. The excitation and emission mechanisms of the 420 nm PSL, which are consistent with the results obtained, are discussed.

Nanto, Hidehito; Murayama, Kazuhiko; Usuda, Takayuki; Endo, Fumitaka; Hirai, Yoshiaki; Taniguchi, Shin-Ichi; Takeuchi, Nozomu

1993-07-01

91

A comparison of 10. 6 micrometer pulsed laser damage in sputtered vs electron beam deposited Ge-coated KCl  

SciTech Connect

Germanium films deposited on KCl substrates by electron beam and sputter techniques have been irradiated at 10.6 ..mu..m. A comparative damage study of germanium films prepared by these techniques under pulsed apparatus was used for this study. Well characterized RAP Bridgeman and Czochralski grown KCl substrates with (100) and (111) orientation were used.

Golubovic, A.; Ewing, W.; Bruce, J.; Comer, J.; Milam, D.

1975-06-18

92

Determination of the absolute specific conductance of primary standard KCl solutions  

Microsoft Academic Search

A determination of the absolute specific conductance of KCl solutions is demonstrated. The measurement is based on the conductance cell with a well defined geometry, having a difference in the removable center tube of accurately measured dimensions. The specific conductance of the solution is obtained from the measured resistances of the cell with and without the center tube and the

Y. C. Wu; K. W. Pratt; W. F. Koch

1989-01-01

93

Corrosion and Microstructure Correlation in Molten LiCl-KCl Medium  

Microsoft Academic Search

Pyrochemical reprocessing in molten chloride salt medium has been considered as one of the best options for the reprocessing of spent metallic fuels of future fast breeder reactors. The unit operations such as salt preparation, electrorefining, and cathode processing involve the presence of molten LiCl-KCl eutectic salt from 673 to 1373 K (400 to 1100 °C). The present work discusses

A. Ravi Shankar; S. Mathiya; K. Thyagarajan; U. Kamachi Mudali

2010-01-01

94

Atomic-scale study of the nonmelting, wetting, and freezing behavior of KCl(100)  

Microsoft Academic Search

The objective of this work is to study the thermodynamic properties of the KCl(100) surface by means of Molecular Dynamics (MD) simulation based on the Fumi-Tosi potential. The reliability of this potential model was tested to be quite accurate from the calculated bulk melting temperature Tm . The latter quantity was derived from the coexistence procedure of both solid and

A. Zaoui; W. Sekkal

2004-01-01

95

The Enthalpy of Solution of SRM 1655 (KCl) in H2O.  

National Technical Information Service (NTIS)

The value for the enthalpy of solution of SRM 1655 (KCl), delta H(500 H2O, 298.15 K)=(235.86 + or - 0.23)J/g-1 or (17.584 + or - 0.017)kJ/mol-1, was obtained from measurements in an adiabatic calorimeter, and confirmed by measurements in an isoperibol cal...

M. V. Kilday

1980-01-01

96

Adsorption of PTCDA on NaCl(100) and KCl(100)  

NASA Astrophysics Data System (ADS)

The adsorption of PTCDA on KCl and NaCl(100) surfaces has been investigated by means of first principles calculations. Besides a variety of adsorbate structures for single molecules and a monolayer of flat lying molecules on plain terraces, the influence of monoatomic steps and the different defect site at step edges has been studied in detail.

Aldahhak, H.; Schmidt, W. G.; Rauls, E.

2013-11-01

97

Quantitative megavoltage radiation therapy dosimetry using the storage phosphor KCl:Eu2+  

PubMed Central

This work, for the first time, reports the use of europium doped potassium chloride (KCl:Eu2+) storage phosphor for quantitative megavoltage radiation therapy dosimetry. In principle, KCl:Eu2+ functions using the same photostimulatated luminescence (PSL) mechanism as commercially available BaFBr0.85I0.15:Eu2+ material that is used for computed radiography (CR) but features a significantly smaller effective atomic number—18 versus 49—making it a potentially useful material for nearly tissue-equivalent radiation dosimetry. Cylindrical KCl:Eu2+ dosimeters, 7 mm in diameter and 1 mm thick, were fabricated in-house. Dosimetric properties, including radiation hardness, response linearity, signal fading, dose rate sensitivity, and energy dependence, were studied with a laboratory optical reader after irradiation by a linear accelerator. The overall experimental uncertainty was estimated to be within ±2.5%. The findings were (1) KCl:Eu2+ showed satisfactory radiation hardness. There was no significant change in the stimulation spectra after irradiation up to 200 Gy when compared to a fresh dosimeter, indicating that this material could be reused at least 100 times if 2 Gy per use was assumed, e.g., for patient-specific IMRT QA. (2) KCl:Eu2+ exhibited supralinear response to dose after irradiation from 0 to 800 cGy. (3) After x ray irradiation, the PSL signal faded with time and eventually reached a fading rate of about 0.1%?h after 12 h. (4) The sensitivity of the dosimeter was independent of the dose rate ranging from 15 to 1000 cGy?min. (5) The sensitivity showed no beam energy dependence for either open x ray or megavoltage electron fields. (6) Over-response to low-energy scattered photons was comparable to radiographic film, e.g., Kodak EDR2 film. By sandwiching dosimeters between low-energy photon filters (0.3 mm thick lead foils) during irradiation, the over-response was reduced. The authors have demonstrated that KCl:Eu2+ dosimeters have many desirable dosimetric characteristics that make the material conducive to radiation therapy dosimetry. In the future, a large-area KCl:Eu2+-based CR plate with a thickness of the order of a few microns, created using modern thin film techniques, could provide a reusable, quantitative, high-resolution two-dimensional dosimeter with minimal energy dependence.

Han, Zhaohui; Driewer, Joseph P.; Zheng, Yuanshui; Low, Daniel A.; Li, H. Harold

2009-01-01

98

Performance of KCl:Eu2+ storage phosphor dosimeters for low-dose measurements  

NASA Astrophysics Data System (ADS)

Recent research has demonstrated that europium doped potassium chloride (KCl:Eu2+) storage phosphor material has the potential to become the physical foundation of a novel and reusable dosimetry system using either film-like devices or devices similar to thermoluminescent dosimeter chips. The purposes of this work are to quantify the performance of KCl:Eu2+ prototype dosimeters for low-dose measurements and to demonstrate how it can be incorporated into clinical application for in vivo peripheral dose measurements. Pellet-style KCl:Eu2+ dosimeters, 6 mm in diameter, and 1 mm thick, were fabricated in-house for this study. The dosimeters were read using a laboratory photostimulated luminescence detection system. KCl:Eu2+ prototype storage phosphor dosimeter was capable of measuring a dose-to-water as low as 0.01 cGy from a 6 MV photon beam with a signal-to-noise ratio greater than 6. A pre-readout thermal annealing procedure enabled the dosimeter to be read within an hour post-irradiation. After receiving large accumulated doses (?10 kGy), the dosimeters retained linear response in the low-dose region with only a 20% loss of sensitivity comparing to a fresh sample (zero Gy history). The energy dependence encountered during low-dose peripheral measurements could be accounted for via a single point outside-field calibration per each beam quality. With further development the KCl:Eu2+?-based dosimeter could become a versatile and durable dosimetry tool with large dynamic range (sub-cGy to 100 Gy).

Li, H. Harold; Xiao, Zhiyan; Hansel, Rachael; Knutson, Nels; Yang, Deshan

2013-06-01

99

Calcium-independent phospholipase A2 participates in KCl-induced calcium sensitization of vascular smooth muscle  

PubMed Central

In vascular smooth muscle, KCl elevates intracellular free Ca2+ ([Ca2+]i), myosin light chain kinase activity and tension (T), but also can inhibit myosin light chain phosphatase activity by activation of rhoA kinase (ROCK), resulting in Ca2+ sensitization (increased T/[Ca2+]i ratio). Precisely how KCl causes ROCK-dependent Ca2+ sensitization remains to be determined. Using fura-2-loaded isometric rings of rabbit artery, we found that the Ca2+-independent phospholipase A2 (iPLA2) inhibitor, bromoenol lactone (BEL), reduced the KCl-induced tonic but not early phasic phase of T and potentiated [Ca2+]i, reducing Ca2+ sensitization. The PKC inhibitor, GF-109203X (? 3?M) and the pseudosubstrate inhibitor of PKC? produced a response similar to BEL. BEL reduced basal and KCl-stimulated myosin phosphatase phosphorylation. Whereas BEL and H-1152 produced strong inhibition of KCl-induced tonic T (~50%), H-1152 did not induce additional inhibition of tissues already inhibited by BEL, suggesting that iPLA2 links KCl stimulation with ROCK activation. The cPLA2 inhibitor, pyrrolidine-1, inhibited KCl-induced tonic increases in [Ca2+]i but not T, whereas the inhibitor of 20-HETE production, HET0016, acted like the ROCK inhibitor H-1152 by causing Ca2+ desensitization. These data support a model in which iPLA2 activity regulates Ca2+ sensitivity.

Ratz, Paul H.; Miner, Amy S.; Barbour, Suzanne E.

2009-01-01

100

Deficiency of Src family kinases Fgr and Hck results in activation of erythrocyte K/Cl cotransport.  

PubMed Central

Src-family kinases play a central role in regulation of hematopoietic cell functions. We found that mouse erythrocytes express the Src-family kinases Fgr and Hck, as well as Lyn. To directly test whether Fgr and Hck play any role in erythrocyte function, we analyzed red cells isolated from fgr-/-, hck-/-, and fgr-/- hck-/- knock-out mice. Mean corpuscular hemoglobin concentration and median density are increased, while K content is decreased, in fgr-/- hck-/- double-mutant erythrocytes compared with wild-type, fgr-/-, or hck-/- erythrocytes. Na/K pump and Na/K/Cl cotransport were not altered, but K/Cl cotransport activity was significantly and substantially higher (approximately three-fold) in fgr-/- hck-/- double-mutant erythrocytes. This enhanced K/Cl cotransport activity did not depend on cell age. In fact, in response to bleeding, K/Cl cotransport activity increased in parallel with reticulocytosis in wild-type erythrocytes, while abnormal K/Cl cotransport did not change as a consequence of reticulocytosis in fgr-/- hck-/- double-mutant erythrocytes. Okadaic acid, an inhibitor of a phosphatase that has been implicated in activation of the K/Cl cotransporter, inhibited K/Cl cotransport in wild-type and fgr-/- hck-/- double-mutant erythrocytes to a comparable extent. In contrast, staurosporine, an inhibitor of a kinase that has been suggested to negatively regulate this same phosphatase enhanced K/Cl cotransport in wild-type but not in fgr-/- hck-/- double-mutant erythrocytes. On the basis of these findings, we propose that Fgr and Hck are the kinases involved in the negative regulation of the K/Cl cotransporter-activating phosphatase. Abnormality of erythrocyte K/Cl cotransport in fgr-/- hck-/- double-mutant animals represents the first demonstration that Src-family kinases may be involved in regulation of membrane transport.

De Franceschi, L; Fumagalli, L; Olivieri, O; Corrocher, R; Lowell, C A; Berton, G

1997-01-01

101

Molecular to ionic transition of BiCl3 in LiCl KCl eutectic melt  

NASA Astrophysics Data System (ADS)

The local structures of molten BiCl3 and its mixtures in LiCl KCl eutectic melt were investigated by X-ray absorption fine structure (XAFS) technique. The first Bi Cl correlation in molten pure BiCl3 shows covalent nature, since the distance was almost the same as sum of the covalent radii of Bi and Cl and the coordination number was almost 3. The similar property was also observed in the mixture of 75% BiCl3 with LiCl KCl eutectic melt. Drastic change was detected in 25% BiCl3 mixture melt. The first Bi Cl distance was the sum of the ionic radii in molten 25% BiCl3 melt. The results suggest that BiCl3 changes from molecular liquid to ionic by mixing with alkali chlorides.

Okamoto, Yoshihiro; Yaita, Tsuyoshi; Minato, Kazuo

2005-07-01

102

Effect of NaCl and KCl doping on the growth of sulphamic acid crystals.  

PubMed

The nonlinear optical single crystals of doped sulphamic acid (SA) were grown from aqueous solution by doping with NaCl and KCl using slow evaporation method. Powder X-ray diffraction studies confirm that the grown crystals belong to orthorhombic system. The density and melting point measurements of the grown crystals were determined by floatation technique and capillary tube method, respectively. The range of optical transmittance was ascertained by recording the UV-Vis-NIR spectrum. Atomic absorption study reveals the presence of dopants in the doped crystals. The thermal analyses indicated that the doped SA crystals are more stable than pure crystals. The Vicker's microhardness studies revealed that the dopants increased the hardness of the crystals. SHG efficiency studies of the crystals are found to be increased in the presence of NaCl and KCl dopants. PMID:21855404

Thaila, T; Kumararaman, S

2011-08-02

103

Redox electrochemistry of europium fluoride complexes in an equimolar NaCl–KCl melt  

Microsoft Academic Search

The electrochemical behavior of europium fluoride complexes was studied by different electrochemical methods at a glassy carbon electrode in the temperature range 973–1100K in the NaCl–KCl melt. The diffusion coefficients of Eu(III) and Eu(II) were determined by linear sweep voltammetry. The standard rate constants of charge transfer for the Eu(III)\\/Eu(II) redox couple were found on the base cyclic voltammetry, impedance

S. A. Kuznetsov; M. Gaune-Escard

2011-01-01

104

Neurotransmitters, KCl and antioxidants rescue striatal neurons from apoptotic cell death in culture  

Microsoft Academic Search

Striatal neurons grown in low density culture on serum-free media and in the absence of glia die within 3 days of plating. In this study, we sought to determine the mechanism of cell death (e.g., apoptosis) and whether trophic influences, such as, growth factors, neurotransmitters, antioxidants or KCl-mediated depolarization could improve their survival. We found that striatal neurons grown in

Lorraine Iacovitti; Natalie D Stull; Amanda Mishizen

1999-01-01

105

Anodic behavior of a carbon plate in an LiCl-KCl binary molten salt  

Microsoft Academic Search

The behavior of a negative pole of a carbon plate (a mixture of graphite with glassy carbon) in a eutectic LiCl-KCl binary molten salt has been investigated at 360–500 °C, as a fundamental study on high temperature lithium secondary cells. Both cyclic voltammetric and galvanostatic charge\\/discharge data suggested that reversible insertion\\/extraction of lithium can take place accompanied by stage formation.

Atsushi Adachi; Yasushi Katayama; Takashi Miura; Tomiya Kishi

1997-01-01

106

Electrodeposition Characteristics of Uranium in Molten LiCl-KCl Eutectic and its Salt Distillation Behavior  

Microsoft Academic Search

Electrorefining experiments with a crucial anode containing U, elemental rare earths; Gd, Nd and Ce or Nd2O3 were carried out in KCL-LiCL eutectic melt at 500°C. Partitioning behavior of the components according to the applied voltage or current was investigated at various initial U concentrations in a molten salt. Elemental REs concentrations in the cathode deposits increased as the applied

Jong-Hyeon LEE; Young-Ho KANG; Sung-Chan HWANG; Joon-Bo SHIM; Byung-Gil AHN; Eung-Ho KIM; Seong-Won PARK

2006-01-01

107

Electrode reaction of the Np3+\\/Np couple in LiCl–KCl eutectic melts  

Microsoft Academic Search

The electrochemical behaviour of the Np3+\\/Np couple in the LiCl–KCl eutectic salt was investigated by electromotive force measurements, cyclic voltammetry and chronopotentiometry in the temperature region between 723 and 823 K. The standard redox potential of the Np3+\\/Np couple vs Ag\\/AgCl (1.00 wt %) was measured and given by the equation, ENp3+\\/Np° = -2.0298 + 0.000706 T, where E is

O. Shirai; M. Iizuka; T. Iwai; Y. Arai

2001-01-01

108

Electrochemical behavior of actinide ions in LiCl–KCl eutectic melts  

Microsoft Academic Search

The electrodeposition and dissolution of uranium and plutonium in LiCl–KCl eutectic salt on tungsten and molybdenum working electrodes were investigated by cyclic voltammetry at 723, 773 and 823K. It is suggested from the voltammograms that the electrodeposition and dissolution of U and Pu, U3+\\/U and Pu3+\\/Pu, may be quasi-reversible, while the redox reaction of U4+\\/U3+ is reversible. The adsorption and

O. Shirai; T. Iwai; Y. Suzuki; Y. Sakamura; H. Tanaka

1998-01-01

109

Investigation of the evaporation of rare earth chlorides in a LiCl–KCl molten salt  

Microsoft Academic Search

Uranium dendrites which were deposited at a solid cathode of an electrorefiner contained a certain amount of salts. These\\u000a salts should be removed for the recovery of pure metal using a cathode processor. In the uranium deposits from the electrorefining\\u000a process, there are actinide chlorides and rare earth chlorides in addition to uranium chloride in the LiCl–KCl eutectic salt.\\u000a The

Sung Bin Park; Dong Wook Cho; Moon Sik Woo; Sung Chan Hwang; Young Ho Kang; Jeong Guk Kim; Hansoo Lee

2011-01-01

110

Study on the distillation rates of LiCl–KCl eutectic salt under different vacuum conditions  

Microsoft Academic Search

A study on the distillation rate of LiCl–KCl eutectic salt under different vacuums from 0.5 to 50Torr was performed by using thermogravimetric (TG) method. A distillation rate of the order of 10?4–10?5molcm?2s?1 was obtainable at temperatures of 1200–1300K and vacuums of 5–50Torr. Based on the non-isothermal TG data, model distillation flux equations could be derived as a function of temperature.

H.-C. Yang; H.-C. Eun; I.-T. Kim

2009-01-01

111

Electrolysis of plutonium nitride in LiCl–KCl eutectic melts  

Microsoft Academic Search

The electrolysis of plutonium nitride, PuN, was investigated in the LiCl–KCl eutectic salt with 0.54 wt% PuCl3 at 773 K in order to understand the dissolution of PuN at the anode and the deposition of metal at the cathode from the viewpoint of the application of a pyrochemical process to nitride fuel cycle. It was found from cyclic voltammetry that

O. Shirai; T Iwai; K Shiozawa; Y Suzuki; Y Sakamura; T Inoue

2000-01-01

112

Stabilization of rare earth nuclides in LiCl-KCl eutectic salt wastes  

Microsoft Academic Search

Distillation and condensation characteristics of LiCl-KCl eutectic salts containing rare earth precipitates were investigated\\u000a and a conversion of the rare earth oxychlorides to oxides was performed. The distillation flux was increased by about 1,000\\u000a times by reducing the pressure from 760 Torr to 0.5 Torr. The composition of the recovered salts was changed according to\\u000a the condensed spot. The conversion

H. C. Eun; H. C. Yang; Y. Z. Cho; H. S. Park; H. S. Lee; I. T. Kim

2009-01-01

113

Corrosion and Microstructure Correlation in Molten LiCl-KCl Medium  

Microsoft Academic Search

Pyrochemical reprocessing in molten chloride salt medium has been considered as one of the best options for the reprocessing\\u000a of spent metallic fuels of future fast breeder reactors. The unit operations such as salt preparation, electrorefining, and\\u000a cathode processing involve the presence of molten LiCl-KCl eutectic salt from 673 to 1373 K (400 to 1100 °C). The present\\u000a work discusses the corrosion

A. Ravi Shankar; S. Mathiya; K. Thyagarajan; U. Kamachi Mudali

2010-01-01

114

First-principles super-cell investigation of the rattling effect in Li-doped KCl  

Microsoft Academic Search

We have studied by the first-principles total energy method the off-center instability of a substitutional Li impurity in KCl. We report here the results of super-cell calculations of the energy associated with displacing the Li along , and directions relative to the K vacancy. To understand the influence of relaxations, we performed three levels of relaxations—only first nearest neighbors of

Xing Gao; Murray S Daw

2009-01-01

115

Ideal Paraelectric Refrigeration in KCl: OH and RbCl: CN  

Microsoft Academic Search

The Carnot-cycle refrigeration characteristics of two probable paraelectric refrigerators KCl: OH and RbCl: CN are studied, according to a thermodynamic model which appears to be basically correct for describing electrocaloric phenomena in these doped salts. A high-temperature reservoir at 1.11°K is assumed for comparison with actual magnetic and He-dilution refrigerators, and the operating characteristics of the paraelectric refrigerators are optimized

W. N. Lawless

1969-01-01

116

Electrolysis of Burnup-Simulated Uranium Nitride Fuels in LiCl-KCl Eutectic Melts  

Microsoft Academic Search

The electrochemical behavior of burnup-simulated uranium nitride fuels containing representative solid fission product elements, UN+Mo (Mo = 2.84 wt%), UN+Pd (Pd = 4.6 wt%) and (U, Nd)N (NdN = 8.0 wt%), was investigated in the molten LiCl-KCl eutectic salt with 0.54 wt% UCl3 in order to clarify the effects of fission products on the dissolution of actinide nitrides and the

Takumi SATOH; Takashi IWAI; Yasuo ARAI

2009-01-01

117

Magnetic properties of Sr-ferrites synthesized in molten ( NaCl + KCl ) flux  

Microsoft Academic Search

The Sr-ferrite powders, SrFe12O19, were synthesized by the molten salt method using (NaCl+KCl) mixture. Particle morphology was homogeneous and hexagonal platelet like. Both particle size and thickness increased as the reaction temperature and time increased. The sintering density of Sr-ferrite magnet prepared with powders by the molten salt method showed the maximum value at the sintering temperature of 1200?C. The

Si-Dong Kim; Jung-Sik Kim

2006-01-01

118

Electrochemical studies on the redox mechanism of uranium chloride in molten LiCl–KCl eutectic  

Microsoft Academic Search

The reduction and oxidation processes on platinum and glassy carbon electrodes in molten LiCl–KCl eutectic containing UCl3 were investigated by cyclic voltammetry (CV), chronopotentiometry and electrochemical impedance spectroscopy (EIS) in the temperature range 660–780K. Two redox peaks have been observed in the cyclic voltammograms corresponding to the two redox reactions U(IV)\\/U(III) and U(III)\\/U which are found to be reversible and

B Prabhakara Reddy; S Vandarkuzhali; T Subramanian; P Venkatesh

2004-01-01

119

Molecular Model for U Centers in NaCl and KCl  

Microsoft Academic Search

In the harmonic approximation, the molecular model has been used to study the vibrations of U centers in NaCl and KCl where we have considered an impurity ion and its nearest neighbors moving while the rest of the crystal is at rest. For interactions we have used the rigid-ion model with short-range forces limited to nearest neighbors only. The 21×21

S. S. Jaswal

1965-01-01

120

Catalytic oxidation of methane over KCl-LnCl 3 eutectic molten salts  

Microsoft Academic Search

The study of the partial oxidation of methane (POM) over KCl-LnCl3 (Ln=La, Ce, Sm, Dy, Yb) eutectic molten salts was undertaken. The reaction main products were hydrocarbons (primarily C2, selectivity >70%). The formation of hydrogen was never detected. The catalytic performance is clearly dependent on the rare earth ions properties and the factors that seem to contribute to the variation

Joaquim B. Branco; Gonçalo Lopes; Ana C. Ferreira

2011-01-01

121

KCl cotransport activity in light versus dense transferrin receptor-positive sickle reticulocytes.  

PubMed Central

A subset of sickle cells becomes K(+)-depleted and dehydrated before or soon after leaving the bone marrow. These young cells may be identified in blood as transferrin receptor-positive (TfR+) dense reticulocytes. KCl cotransport, which is normally active in young erythroid cells with a maximum at pH 6.8, is a candidate pathway for K+ depletion of sickle reticulocytes. In this investigation, KCl cotransport activity was evaluated in young, TfR+ cells which had become dense in vivo and in age-matched cells which had retained normal hydration. Sickle erythrocytes were first separated into three primary density fractions, with care taken to preserve the in vivo hydration state. After normalization of intracellular hemoglobin concentration with nystatin, the cells were incubated at 37 degrees C for 20 min at pH 6.8 and 7.4. Before and after incubation, each primary fraction was separated into four secondary density fractions. The percentage of TfR+ cells in each secondary fraction was measured and a density distribution for TfR+ cells was determined for each primary fraction before and after incubation. The density shift during incubation was a measure of KCl cotransport. TfR+ cells from the denser primary fractions II and III had significantly more density shift than TfR+ cells from the light fraction I. Although the shifts were larger at low pH, differences between primary fractions were also observed at pH 7.4. These data indicate that the cells which become dense quickly in vivo have more KCl cotransport activity than those which remain light in vivo, and support this pathway as a primary mechanism for dehydration of young sickle cells.

Franco, R S; Palascak, M; Thompson, H; Joiner, C H

1995-01-01

122

Modulation characteristics of volume holographic gratings recorded in KCl:Ca crystals  

Microsoft Academic Search

Modulation characteristics of volume holographic gratings stored in KCl:Ca crystals utilizing the F - Z1 color-center conversion have been studied. By means of the Hurter-Driffield curve the absorption and refractive-index modulation amplitudes have been determined at the optimum working point. Further, the experimental and calculated diffraction-efficiency values obtained by using two dissimilar solutions of the coupled wave equations are given.

J. Ruuskanen

1979-01-01

123

Characterization of Fe/KClO4 heat powders and pellets.  

SciTech Connect

Pellets of Fe/KClO{sub 4} mixtures are used as a heat source for thermally activated ('thermal') batteries. They provide the energy necessary for melting the electrolyte and bringing the battery stack to operating temperature. The effects of morphology of the Fe and the heat-pellet density and composition on both the physical properties (flowability, pelletization, and pellet strength) and the pyrotechnic performance (burn rate and ignition sensitivity) were examined using several commercial sources of Fe.

Reinhardt, Frederick William; Guidotti, Ronald Armand; Odinek, Judy Gail

2005-04-01

124

Methane hydrate phase equilibrium in the presence of salt (NaCl, KCl, or CaCl 2) + ethylene glycol or salt (NaCl, KCl, or CaCl 2) + methanol aqueous solution: Experimental determination of dissociation condition  

Microsoft Academic Search

In this communication, we report dissociation conditions of methane hydrates in the presence of salt (NaCl, KCl, or CaCl2)+ethylene glycol or salt (NaCl, KCl, or CaCl2)+methanol aqueous solutions at different temperatures. The equilibrium data were generated using an isochoric pressure-search method. These data are compared with some selected experimental data from the literature on dissociation conditions of methane hydrates in

Amir H. Mohammadi; Dominique Richon

2009-01-01

125

Diffusion coefficients of cerium and gadolinium in molten LiCl-KCl  

SciTech Connect

The most important step in the pyrometallurgical reprocessing is the electrorefining in molten chlorides. In this step, spent metal fuel is anodically dissolved into LiCl-KCl eutectic melt, and the actinides are selectively recovered at the cathodes due to the differences among the redox potentials of the elements, while fission products remain in the anode and in the electrolyte salt. The diffusion coefficients of Ce(III) and Gd(III) in LiCl-KCl eutectic melt were determined in the temperature range between 673 and 823 K by chronopotentiometry. A new method was devised to minimize the error in defining the surface area of the working electrode. The immersed depth of the working electrode was changed by stages, and the relation between the change in the square root of the transition time and that in the surface area of the working electrode was substituted into the Sand equation instead of their absolute values. The activation energies for diffusion and the diffusion coefficients of lanthanide ions in LiCl-KCl are discussed in connection with their ionic radii and the stability of their complex ions.

Iizuka, Masatoshi [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

1998-01-01

126

On the electrochemical formation of Pu-Al alloys in molten LiCl-KCl  

NASA Astrophysics Data System (ADS)

Properties of Pu-Al alloys were investigated in connection with development of pyrochemical methods for reprocessing of spent nuclear fuel. Electroseparation techniques in molten LiCl-KCl are being developed in ITU to group-selectively recover actinides from the mixture with fission products. In the process, actinides are electrochemically reduced on solid aluminium cathodes, forming solid actinide-aluminium alloys. This article is focused on electro-chemical characterisation of Pu-Al alloys in molten LiCl-KCl, on electrodeposition of Pu on solid Al electrodes and on determination of chemical composition and structure of the formed alloys. Cyclic voltammetry and chronopotentiometry were used to study Pu-Al alloys in the temperature range 400-550 °C. Pu is reduced to metal in one reduction step Pu3+/Pu0 on an inert W electrode. On a reactive Al electrode, the reduction of Pu3+ to Pu0 occurs at a more positive potential due to formation of Pu-Al alloys. The open circuit potential technique was used to identify the alloys formed. Stable deposits were obtained by potentiostatic electrolyses of LiCl-KCl-PuCl3 melts on Al plates. XRD and SEM-EDX analyses were used to characterise the alloys, which were composed mainly of PuAl4 with some PuAl3. In addition, the preparation of PuCl3 containing salt by carbochlorination of PuO2 is described.

Mendes, E.; Malmbeck, R.; Nourry, C.; Sou?ek, P.; Glatz, J.-P.

2012-01-01

127

Supercooling of aqueous NaCl and KCl solutions under acoustic levitation.  

PubMed

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. PMID:17042605

Lü, Y J; Wei, B

2006-10-14

128

Phase relations in the hydrous CMAS pyrolite in presence of KCl at 2 GPa  

NASA Astrophysics Data System (ADS)

In the upper mantle, chlorides are constituents of concentrated aqueous solutions (brines), as well as chloride-carbonate and carbonatite melts. Mineral assemblages coming from diverse depth levels show that mobile (K, Na)Cl-bearing fluids are able to provoke intensive metasomatism of the peridotitic mantle accompanied by melting. Scarce experimental studies on influence of brines on mineral equilibria in the peridotitic mantle (Stalder et al., 2008; Chu et al., 2011) indicate that influence of chlorides on water activity in a fluid equilibrated with forsterite enstatite at pressures above 2 GPa is very similar to their effect at lower "crustal" pressures (e.g. Aranovich, Newton, 1997): decrease of the H2O activity with an increase of the salt content results in an increase of the melting temperature of silicates. Nevertheless, these experiments were performed in the Al-free systems. Presence of Al would provoke an active interaction of alkali chlorides, namely KCl, with silicates with formation of new K-Al-bearing phases, such as phlogopite (in presence of H2O), which would influence on the melting of complex assemblages. In order to investigate an effect of KCl on phase relations in the Al2O3, CaO, Na2O-rich hydrous peridotite and on stability of garnet, pyroxenes, and amphiboles, in particular, experiments on interaction of the model CMAS pyrolite Fo57En17Prp14Di12 (+0.3 wt. % of Na2O) with the H2O-KCl fluid were performed at 2 GPa in the temperature interval 900-1200. Mixtures of synthetic forsterite, diopside, enstatite and pyrope in the above weight ratio were mixed with 14 wt. % of Mg(OH)2 corresponding to 4.4 wt. % of H2O in the system. 2.4, 3.7, 5 and 10 wt. % of KCl were added to silicate-H2O mixture. Experiments were performed using a piston-cylinder apparatus with ½-inch talc high-pressure cells calibrated via brucite = periclase + H2O and albite = jadeite + quartz equilibria curves. Temperature was controlled with accuracy ?1 with the W95Re5/W80Re20 thermocouple. Spherical and tube Pt capsules with 0.2 mm-thick walls were used in the experiments. Run products were analyzed using CamScan MV2300 (VEGA TS 5130MM) electron microscope equipped with EDS INCA-Energy-250. The subsolidus assemblage of the model pyrolite (< 1025OC) containing 4.4 wt. % of H2O at 2.5 GPa includes forsterite (Fo), low-Al2O3 (below 0.5 wt. %) clinopyroxene (Cpx), orthopyroxene (Opx) with up to 7 wt. % of Al2O3, pargasite-tschermackite amphibole (Amp), pyrope-grossular garnet (Grt), and minute spinel (Spl). It is consistent with the results of experiments with amphibole-bearing lherzolite (e.g. Niida, Green, 1999). Reaction relations 3/2Opx + 1/2Fo + 1/2Amp = Grt + Cpx + 1/2H2O are observed in the run samples. Melting apparently begins in the temperature interval 1025-1050 and results in gradual disappearance of amphibole. In general, similar relations are available in presence of 2.4 wt. % of KCl. However, reaction 6Opx + Fo + Amp + KCl = [Cl-Phl + Phl] + Grt + 2Cpx results in formation of Cl-bearing phlogopite solid solution, Phl (up to 1 wt. % of Cl). It seems to be stable at higher temperatures (apparently, above 1200) with respect to amphibole, consistently with the experimental data on melting of phlogopite and amphibole-bearing peridotites at pressures >1.5 GPa (Modreski, Boettcher, 1973; Mysen, Boettcher, 1975; Mengel, Green, 1989). Garnet, orthopyroxene, and amphibole, i.e. all alumina-rich phases of the "starting" KCl-free peridotite, are totally disappear with addition of 3.7 wt. % and more of KCl, while the assemblage of Cl-bearing phlogopite with Al-poor clinopyroxene and olivine is stable. The solidus temperature of the H2O-bearing pyrolite with addition of KCl is about 900 at 2.4 wt.% of KCl and seems to be much lower at 10 wt. % of KCl. Anyway, these temperatures are more than by 100 lower of the melting temperature of the H2O-bearing pyrolite without KCl, as well as Cl-free Di+Phl assemblage (Modreski, Boettcher, 1973). Apparently, decrease of the temperature is related to solubility of Cl in

Safonov, O.

2012-04-01

129

[Application of ICP-MS to detecting ten kinds of heavy metals in KCl fertilizer].  

PubMed

With the rapid development of society, more and more attention has been focused on environmental safety, especially on the pollutions of heavy metals, pesticides, persistent organic pollutants and deleterious microorganism. Heavy metals are difficult to metabolize in human body are quite harmful, so research on the pollution of heavy metals is increasingly important. There are many pollution sources of heavy metals, including waste residue, waste water and exhaust gas from industry and automobile, and garbage from human life. The contents of 10 kinds of heavy metals (Cr, Ni, Cu, As, Cd, Sn, Sb, Hg, Tl and Pb) in potassium fertilizer (KCl) from Russia were analyzed by ICP-MS. The results showed that potassium fertilizer (KCl) contained less heavy metals than organic-inorganic compound fertilizer; the content of heavy metals Cr, Ni, Cu, As, Cd, Sn, Sb, Hg, Tl and Pb is 0.00, 65.54, 238.85, 190.60, 0.98, 14.98, 2.97, 10.04, 1.28 and 97.42 ng x g(-1), respectively, which accords with the correlative standards. All the data showed that if potassium fertilizer (KCl) is manufactured through normal channel, the content of heavy metals should be little and safe. PMID:19123423

Rui, Yu-kui; Shen, Jian-bo; Zhang, Fu-suo; Yan, Yun; Jing, Jing-ying; Meng, Qing-feng

2008-10-01

130

Electrochemical Removal of AlCl3 from LiCl-KCl Melts  

NASA Astrophysics Data System (ADS)

In order to remove impurity AlCl3 from LiCl-KCl melts before Li electrolysis, the Al3+ reduction potential on a tungsten electrode and the relation between Al3+ reduction peak current and AlCl3 concentration in LiCl-KCl-AlCl3 melts were determined by cyclic voltammetry (CV). Constant potential electrolysis at -1.6 V vs Cl2/Cl- on both solid Fe and liquid Zn cathodes was performed to remove AlCl3 impurity from the LiCl-KCl-AlCl3 melts. The removal rate of Al3+ from the melts was analyzed by both electrochemical methods and inductively coupled plasma-atomic emission spectrometry (ICP-AES) analysis. The results showed that 96.11 wt pct of Al were removed on a Fe cathode and 99.90 wt pct on a Zn cathode through 10 hours electrolysis, respectively. While stirring the melts by argon gas, 99.21 wt pct of Al3+ was separated from the melts by 4 hours of electrolysis at 723 K (450 °C), which effectively expedited the Al3+ electrochemical reduction rate and shortened the electrolysis time.

Shen, M.; Li, B.; Li, S. Z.; Yu, J. G.

2012-05-01

131

Electrochemical Removal of AlCl3 from LiCl-KCl Melts  

NASA Astrophysics Data System (ADS)

In order to remove impurity AlCl3 from LiCl-KCl melts before Li electrolysis, the Al3+ reduction potential on a tungsten electrode and the relation between Al3+ reduction peak current and AlCl3 concentration in LiCl-KCl-AlCl3 melts were determined by cyclic voltammetry (CV). Constant potential electrolysis at -1.6 V vs Cl2/Cl- on both solid Fe and liquid Zn cathodes was performed to remove AlCl3 impurity from the LiCl-KCl-AlCl3 melts. The removal rate of Al3+ from the melts was analyzed by both electrochemical methods and inductively coupled plasma-atomic emission spectrometry (ICP-AES) analysis. The results showed that 96.11 wt pct of Al were removed on a Fe cathode and 99.90 wt pct on a Zn cathode through 10 hours electrolysis, respectively. While stirring the melts by argon gas, 99.21 wt pct of Al3+ was separated from the melts by 4 hours of electrolysis at 723 K (450 °C), which effectively expedited the Al3+ electrochemical reduction rate and shortened the electrolysis time.

Shen, M.; Li, B.; Li, S. Z.; Yu, J. G.

2011-12-01

132

Interfacial tension between aluminum and NaCl-KCl-based salt systems  

NASA Astrophysics Data System (ADS)

Aluminum scrap is frequently remelted under a NaCl-KCl based salt flux cover to prevent oxidation, to aid in the stripping of oxide films, and to improve drop coalescence. In this process, the interfacial tension between the aluminum metal and the salt flux plays an important role. However, the measurement of interfacial tensions at high temperature is difficult and prone to errors. Therefore, an interfacial tension model, presented in this article, has been developed. The interfacial tension between aluminum and NaCl-KCl based melts does not change with the addition of chlorides or with variations in the composition of the NaCl-KCl melt. On the other hand, the addition of fluorides decreases the interfacial tension to various extents due to the adsorption of sodium and/or potassium at the interface. Addition of AlF3 is the least effective; additions of LiF, MgF2, CaF2, BaF2, or SrF2 are moderately effective; and additions of NaF or KF are the most effective in lowering the interfacial tension.

Roy, Raja R.; Utigard, Torstein A.

1998-08-01

133

Increased Proteolysis of Senescing Rice Leaves in the Presence of NaCl and KCl 1  

PubMed Central

NaCl and KCl enhanced the degradation of chlorophylls and proteins in detached rice (Oryza sativa) leaves in a concentration-dependent manner. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) accounted for 73 to 80% of the protein lost by day 4 in the light. NaCl at 50 millimolar increased proteolysis by 21% over the control in 4 days, but the addition of cycloheximide reduced the increase to about one-half. Cycloheximide alone had no effect on proteolytic activity during this period. Leaf segments taken from 10-day-old seedlings contained the highest proteolytic activity. Both NaCl and KCl increased the activity of Rubisco-degrading endoproteinases (the amount of ninhydrin-positive compounds measured from HCl-hydrolyzates of trichloroacetic acid-soluble supernatant), but decreased the activity of hemoglobin- and Rubisco-degrading exoproteinases (the amount of ninhydrin-positive compounds measured directly from trichloroacetic acid-soluble supernatant). Efflux of amino acids from senescing leaf segments into the incubation media increased 7- and 12-fold in the presence of KCl and NaCl, respectively. The increased efflux resulted in a negative correlation between salt concentration and amino acid content of leaf segments at the later stage of senescence. It is concluded that, in addition to the induction of new proteinase synthesis, the increased efflux of protein hydrolyzates may play a significant role in increasing proteolysis of salt-treated leaves, especially at the later stages of senescence.

Kang, Seong-Mo; Titus, John S.

1989-01-01

134

(Na--K-2Cl) and (K-Cl) co-transport in duck red cells  

SciTech Connect

(Na-K-2Cl) co-transport is associated with a concurrent 1:1 obligate cation exchange. In high potassium cells, the predominant mode is K/K (or K/Rb) exchange. In high sodium cells (nystatin technique), it is Na/Na (or Na/Li) exchange. We suggest these exchanges represent partial reactions of the co-transporter in which fully loaded forms cross the membrane, partially unload, then reload one or more ions, and return. Under all circumstances, regardless of the direction of movement, the stoichiometry of net transport is 1Na:1K:2Cl. We find no evidence for electrogenic and/or independent net movement of (Na-Cl) or (K-Cl), therefore partially loaded carriers are not transportable. The absolute ion requirements of the two modes differ markedly: K/K exchange operates in the absence of external sodium, but requires it internally, and must have the other co-ions (K, Cl) on both sides of the membrane. Na/Na exchange requires all three co-ions (Na, K, Cl) externally, but only sodium in the cell. {sup 36}Chloride influx studies suggest that the K/K mode is actually KCl/KCl exchange. Nontransportable lyotropic anions interfere with co-transport.

Lytle, C.Y.

1988-01-01

135

Enhancement by L-methionine of contractile responses to acetylcholine and high KCl in uterine segment.  

PubMed

The contractile responses of isolated uterine segments from 17 beta-estradiol-3-benzoate-treated ovariectomized rats to acetylcholine (ACh) and high KCl in Ca-depleted modified Locke-Ringer solution on addition of CaCl2 were used as indicators of Ca2+ influxes through ACh receptor- and voltage-operated Ca2+ channels, respectively. L-Methionine (L-Met) significantly enhanced these responses. The enhancement depended on the time of treatment with L-Met and concentration of L-Met. 3-Deazaadenosine (3-DAA) plus homocysteine thiolactone (HCTL), which inhibit S-adenosylmethionine-dependent methylation, caused dose-dependent inhibition of these contractile responses to ACh and high KCl. These inhibitory effects of 3-DAA plus HCTL were significantly attenuated in the presence of L-Met. Protein carboxylmethyltransferase and phospholipid methyltransferase activities were detected in the isolated uterine segment under conditions similar to those in which the contractile responses were observed. 3-DAA plus HCTL inhibited these enzyme activities. These findings suggest that S-adenosylmethionine-dependent methylations of protein and/or phospholipid in isolated uterine segment are involved in the contractile responses to ACh and high KCl in Ca-depleted modified Locke-Ringer solution on addition of CaCl2. PMID:3626184

Ichida, S; Moriyama, M; Yoshioka, K; Ariyoshi, S

1987-05-01

136

Cytotoxicity Inhibition Studies Using 3 M KCl Solubilized Murine Histocompatibility Antigens and a New Multiple Automated Sample Harvester.  

National Technical Information Service (NTIS)

Murine histocompatibility antigens were solubilized by hypertonic salt (3 M KCl) extraction of spleen cells from various inbred strains of mice. These solubilized extracts were applied to a Sephadex G-200 gel column and it was determined that the elution ...

A. Ahmed G. B. Thurman W. E. Vannier K. W. Sell D. M. Strong

1972-01-01

137

Influence of crystallographic structure on the humidity sensing properties of KCl-doped TiO 2 nanofibers  

Microsoft Academic Search

Pure and KCl-doped TiO2 nanofibers with different crystallographic structures are synthesized by electrospinning and calcination techniques, and their humidity sensing properties are investigated. KCl-doped TiO2 nanofibers with mixed anatase and rutile structures show the highest sensing performance. The impedance of this sample linearly decreases by more than four orders of magnitude with increasing relative humidity from 11% to 95% on

Qi Qi; Yingliang Feng; Tong Zhang; Xuejun Zheng; Geyu Lu

2009-01-01

138

Activity coefficients of actinide and rare-earth chlorides in molten LiCl\\/KCl eutectic salt  

Microsoft Academic Search

Using a numerical Gibbs free-energy minimization technique, the activity coefficients of actinide and rare-earth chlorides in molten LiCl\\/KCl eutectic at 450 C have been calculated. Laboratory tests of an electrochemical process for separating actinide metals from rare-earth metals in LiCl\\/KCl solvent at 450 C provided experimental concentration and cathode potential data. The generalized expansion by Wohl was used to express

Tom B. Bechtel; Truman S. Storvick

1999-01-01

139

Kinetics of DIDS inhibition of swelling-activated K-Cl contrasport in low K sheep erythrocytes  

Microsoft Academic Search

The inhibitory effect of various stilbene disulfonates was examined on the swelling-activated Cl-dependent K transport (K-Cl cotransport) in low K sheep erythrocytes. Both diisothiocy-anatostilbenes H2DIDS and DIDS were found to be potent inhibitors. The DIDS concentration yielding 50% inhibition (IC50) of KCl cotransport was 60 µm in the absence of external K and 3 µm at physiological K concentration. Other

E. Delpire; P. K. Lauf

1992-01-01

140

Ionic Molar Conductivities in Solutions of KCl, NaCl and LiCl in Glycerol at 25°C  

Microsoft Academic Search

Conductivities of solutions of KCl, NaCl and LiCl in glycerol at 25°C have been measured for concentrations in the range 0.0005 to 0.5 mol dm, and values of molar conductivity at infinite dilution obtained by extrapolation. Using previously measured transference numbers for KCl dissolved in glycerol, values of ionic molar conductivities at infinite dilution have been deducted for K, Na,

M. C. Blanco; D. C. Champeney; M. Kameche

1989-01-01

141

Incorporation of Lactobacillus casei in Iranian ultrafiltered Feta cheese made by partial replacement of NaCl with KCl.  

PubMed

Probiotic Iranian ultrafiltered Feta cheese was produced from ultrafiltration of milk with a volumetric concentration factor of 4.5:1. The heat-treated retentates were inoculated with 10(7) cfu of Lactobacillus casei LAFTI L26/mL. A mesophilic-thermophilic mixed culture of Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris, and Streptococcus thermophilus was also used. Three percent (wt/wt) salt with different ratios of NaCl:KCl (100% NaCl, 50% NaCl:50% KCl, 75% NaCl:25% KCl, and 25% NaCl:75% KCl) were used in cheese formulation. The viability of L. casei was determined in treatments during the ripening period (90d at 5°C) within 15-d intervals. The pH, titratable acidity, and redox potential changes were monitored throughout the mentioned period. The mean pH drop rate, mean acidity increase rate, and mean redox potential increase rate were calculated at the end of the storage period. Also, total nitrogen, water-soluble nitrogen, lactic acid, and acetic acid concentrations, and syneresis and sensory characteristics of the product were measured during the mentioned period every 30d. The maximum viability of L. casei was observed within d 15 to 30 of the ripening period in the treatment containing the lowest amount of sodium. Addition of KCl enhanced syneresis. Cheeses with NaCl alone and with only 25% replacement by KCl have the highest sensory acceptability. PMID:22818434

Karimi, R; Mortazavian, A M; Karami, M

2012-08-01

142

Simple large-scale synthesis of hydroxyapatite nanoparticles: in situ observation of crystallization process.  

PubMed

The noble synthesis method for hydroxyapatite (HAp) nanoparticles was exploited using a fairly simple reaction of Ca(OH)(2) and H(3)PO(4), which does not generate residual harmful anions and consequently does not need an additional washing process. HAp nanoparticles were found to yield from dicalcium phosphate dehydrate (DCPD) as the only intermediate phase, which was monitored by in situ observation study using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), (1)H and (31)P magic-angle spinning (MAS) NMR. Furthermore, we found that the phase evolution of HAp was preceded by heteronucleation of HAp onto the DCPD surface. The combination of scanning electron microscopy (SEM) and inductively coupled plasma atomic emission spectroscopy (ICP-ES) analysis gave more information on the HAp crystallization process, which was found to be retarded by the residual Ca(OH)(2) and slow diffusion process of Ca ions into the interface between HAp and DCPD. These results demonstrate that the synthesis of pure HAp nanoparticles with high throughput can be achieved by controlling the residual Ca(OH)(2) and diffusion process of Ca ions. PMID:19810677

Kim, Dong Wook; Cho, In-Sun; Kim, Jin Young; Jang, Hae Lin; Han, Gill Sang; Ryu, Hyun-Seung; Shin, Heungsoo; Jung, Hyun Suk; Kim, Hyungtak; Hong, Kug Sun

2010-01-01

143

Thermal Properties of LiCl-KCl Molten Salt for Nuclear Waste Separation  

SciTech Connect

This project addresses both practical and fundamental scientific issues of direct relevance to operational challenges of the molten LiCl-KCl salt pyrochemical process, while providing avenues for improvements in the process. In order to understand the effects of the continually changing composition of the molten salt bath during the process, the project team will systematically vary the concentrations of rare earth surrogate elements, lanthanum, cerium, praseodymium, and neodymium, which will be added to the molten LiCl-KCl salt. They will also perform a limited number of focused experiments by the dissolution of depleted uranium. All experiments will be performed at 500°C. The project consists of the following tasks. Researchers will measure density of the molten salts using an instrument specifically designed for this purpose, and will determine the melting points with a differential scanning calorimeter. Knowledge of these properties is essential for salt mass accounting and taking the necessary steps to prevent melt freezing. The team will use cyclic voltammetry studies to determine redox potentials of the rare earth cations, as well as their diffusion coefficients and activities in the molten LiCl-KCl salt. In addition, the team will perform anodic stripping voltammetry to determine the concentration of the rare earth elements and their solubilities, and to develop the scientific basis for an on-line diagnostic system for in situ monitoring of the cation species concentration (rare earths in this case). Solubility and activity of the cation species are critically important for the prediction of the salt's useful lifetime and disposal.

Kumar Sridharan; Todd Allen; Mark Anderson

2012-11-30

144

Evidence for a KCl-Stimulated, Mg2+-ATPase on the Golgi of Corn Coleoptiles 1  

PubMed Central

Membranes of corn (Zea mays, cv Trojan 929) coleoptiles were fractionated by sucrose density gradient centrifugation and the locations of organelles were determined using marker enzymes and electron microscopy. Latent IDPase (or UDPase) was selected as the Golgi marker and UDPG-sterol glucosyl transferase was selected as the plasma membrane (PM) marker, because they were clearly separable from markers for the other organelles. Golgi-rich and PM-rich fractions were studied in relation to their ATPase activities. The pH optimum of the KCl, Mg2+-ATPase of the PM-rich fraction from a step gradient was 6.0 to 6.5, while the Golgi-rich fraction had peaks at pH 6.0 to 6.5 and pH 7.5. It is hypothesized that the peak at pH 6.0 to 6.5 for the Golgi-rich fraction is due to PM-contamination, while the peak at pH 7.5 represents the activity of a Golgi ATPase. To reduce PM contamination, Golgi-rich fractions obtained from step or rate-zonal gradients were recentrifuged isopycnically on linear sucrose gradients. The distribution of KCl, Mg2+-ATPase activity was measured at pH 6.5 and 7.5. The pH 6.5 ATPase was coincident with UDPG-sterol glucosyl transferase, a PM marker, while the pH 7.5 ATPase overlapped with latent UDPase, a Golgi marker. These results provide strong evidence for a KCl, Mg2+-ATPase, active at pH 7.5, associated with the Golgi membranes of corn coleoptiles. Images Fig. 5

Chanson, Alain; McNaughton, Eugenia; Taiz, Lincoln

1984-01-01

145

Temperature dependence of fluorescence for EuCl3 in LiCl-KCl eutectic melt.  

PubMed

The fluorescence of EuCl(3) in LiCl-KCl eutectic melt according to temperature changes was investigated, and the spontaneous partial reduction of Eu(3+) to Eu(2+) at high temperature was confirmed by the fluorescence results. The fluorescence decreases when the temperature increases, and this was examined in detail. The studies of fluorescence provided information regarding the chemical and physical behavior of europium ions in the molten salt according to the temperature changes. It is applicable for monitoring species and concentrations and estimating the approximate chemical structure of the ions in molten salts. PMID:20678668

Im, Hee-Jung; Kim, Tack-Jin; Song, Kyuseok

2010-06-25

146

Grain boundary properties of ice doped with small concentrations of potassium chloride (KCl)  

NASA Astrophysics Data System (ADS)

The grain boundary (GB) migration rate was studied in ice bicrystals obtained from 1 to 10 µmol l-1 (0.02 to 0.2 ppm) potassium chloride (KCl) water solutions and annealed at temperatures above -20 °C for 170 days. GB mobility was determined as a function of annealing temperature and solute concentration. The GB mobility values obtained show a systematic dependence on the solute concentration. For the first time, it was observed in ice that small concentrations of impurity decrease the GB mobility, as occurs in other materials. The results also indicate possible changes of the GB structure in the annealing temperature range studied.

Nasello, O. B.; Di Prinzio, C. L.; Guzmán, P. G.

2007-06-01

147

Humidity sensing properties of KCl-doped Cu–Zn\\/CuO–ZnO nanoparticles  

Microsoft Academic Search

Cu–Zn alloy nanoparticles in mass production are synthesized through a wire electrical explosion (WEE) method. The atoms on the surface of the as-synthesized nanoparticles are oxidized to form the Cu–Zn\\/CuO–ZnO nanoparticles (CZ\\/CZNs). The humidity sensing properties of CZ\\/CZNs and KCl-doped Cu–Zn\\/CuO–ZnO nanoparticles (KCZ\\/CZNs) are investigated by screen-printing them on ceramic substrates with Ag–Pd interdigitated electrodes, respectively. The measurement results show

Qi Qi; Tong Zhang; Yi Zeng; Haibin Yang

2009-01-01

148

Acidity of KCl extracts from organic horizons of podzolic soils: Sources and possible equilibria  

NASA Astrophysics Data System (ADS)

Samples from the organic horizons of taiga podzolic soils of the Komi Republic were studied, and the possible equilibria established in the soil-KCl solution system ( c = 1 mol/l) at the determination of the exchangeable acidity by the Sokolov method were examined. It was shown that the exchangeable acidity was due to aluminum(III) ions in 6% of the samples with pHKCl?4 and due to the H+ ions formed during the dissociation of water-soluble organic acids in the other samples. A group of samples from the horizons in which Fe3+ ions could appreciably contribute to the soil acidity was discriminated.

Shamrikova, E. V.

2010-07-01

149

Deep Subthreshold ?- Production in Ar+KCl Reactions at 1.76AGeV  

NASA Astrophysics Data System (ADS)

We report first results on a deep subthreshold production of the doubly strange hyperon ?- in a heavy-ion reaction. At a beam energy of 1.76AGeV the reaction Ar+KCl was studied with the High Acceptance Di-Electron Spectrometer at SIS18/GSI. A high-statistics and high-purity ? sample was collected, allowing for the investigation of the decay channel ?-???-. The deduced ?-/(?+?0) production ratio of (5.6±1.2-1.7+1.8)×10-3 is significantly larger than available model predictions.

Agakishiev, G.; Balanda, A.; Bassini, R.; Belver, D.; Belyaev, A. V.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Braun-Munzinger, P.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; Díaz, J.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Fabbietti, L.; Fateev, O. V.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Golubeva, M.; González-Díaz, D.; Guber, F.; Hennino, T.; Holzmann, R.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kotte, R.; Krizek, F.; Krücken, R.; Kühn, W.; Kugler, A.; Kurepin, A.; Lang, S.; Lange, J. S.; Lapidus, K.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Morinière, E.; Mousa, J.; Müntz, C.; Naumann, L.; Otwinowski, J.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Sudol, M.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Wagner, V.; Weber, M.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y. V.; Zhou, P.; Zumbruch, P.

2009-09-01

150

Hyperon production in Ar + KCl collisions at 1.76A GeV  

NASA Astrophysics Data System (ADS)

We present transverse momentum spectra, rapidity distribution and multiplicity of ? -hyperons measured with the HADES spectrometer in the reaction Ar(1.76AGeV) + KCl . The yield of ?^{{-}}_{} is calculated from our previously reported ?^{{-}}_{}/( ? + ?^{{0}}_{}) ratio and compared to other strange particle multiplicities. Employing a strangeness balance equation the multiplicities of the yet unmeasured ?^{{±}}_{} -hyperons can be estimated. Finally a statistical hadronization model is used to fit the yields of ?-_{} , K+, K 0 s , K-, ? , ? and ?-_{} . The resulting chemical freeze-out temperature of T = (76±2) MeV is compared to the measured slope parameters obtained from fits to the transverse mass distributions of the different particles.

Agakishiev, G.; Balanda, A.; Bannier, B.; Bassini, R.; Belver, D.; Belyaev, A.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; D?az, J.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Epple, E.; Fabbietti, L.; Fateev, O.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Golubeva, M.; González-D?az, D.; Guber, F.; Gumberidze, M.; Heilmann, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Huck, P.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kotte, R.; Krizek, F.; Krücken, R.; Kühn, W.; Kugler, A.; Kurepin, A.; Lang, S.; Lange, J. S.; Lapidus, K.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Morinière, E.; Mousa, J.; Müntz, C.; Naumann, L.; Otwinowski, J.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pérez Cavalcanti, T.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Wagner, V.; Weber, M.; Wendisch, C.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y.; Zhou, P.; Zumbruch, P.

2011-02-01

151

An investigation of the critical liquid-vapor properties of dilute KCl solutions  

USGS Publications Warehouse

The three parameters that define the critical point, temperature, pressure, and volume have been experimentally determined by means of filling studies in a platinum-lined system for five KCl solutions ranging from 0.006 to 0.568 m. The platinum-lined vessels were used to overcome the problems with corrosion experienced by earlier workers. The critical temperature (tc), pressure (Pc), and volume (Vc) were found to fit the equations {Mathematical expression} from infinite dilution to 1.0 m. ?? 1976 Plenum Publishing Corporation.

Potter, II, R. W.; Babcock, R. S.; Czamanske, G. K.

1976-01-01

152

Fabrication of polyethersulfone (PES) membranes with nano-porous surface using potassium perchlorate (KClO 4) as an additive in the casting solution  

Microsoft Academic Search

Polyethersulfone (PES) membranes with nano-porous surface were fabricated by addition of potassium perchlorate (KClO4) as an additive in the casting solution. The membranes were prepared from PES\\/polyvinylpyrrolidone (PVP)\\/KClO4\\/dimethylacetamide (DMAc) via phase inversion induced by immersion precipitation technique. Mixture of water and isopropyl alcohol (IPA) was used as coagulation medium. The viscosity of PES casting solution increased with addition of KClO4.

Ahmad Rahimpour; Sayed Siavash Madaeni; Yaghoub Mansourpanah

2010-01-01

153

Phase relations in the system NaCl-KCl-H2O: IV. Differential thermal analysis of the sylvite liquidus in the KCl-H2O binary, the liquidus in the NaCl-KCl-H2O ternary, and the solidus in the NaCl-KCl binary to 2 kb pressure, and a summary of experimental data for thermodynamic-PTX analysis of solid-liquid equilibria at elevated P-T conditions  

USGS Publications Warehouse

The sylvite liquidus in the binary system KCl-H2O and the liquidus in the ternary system NaCl-KCl-H2O were determined by using isobaric differential thermal analysis (DTA) cooling scans at pressures up to 2 kbars. Sylvite solubilities along the three-phase curve in the binary system KCl-H2O were obtained by the intersection of sylvite-liquidus isopleths with the three-phase curve in a P-T plot. These solubility data can be represented by the equation Wt.% KCl (??0.2) = 12.19 + 0.1557T - 5.4071 ?? 10-5 T2, where 400 ??? T ??? 770??C. These data are consistent with previous experimental observations. The solidus in the binary system NaCl-KCl was determined by using isobaric DTA heating scans at pressures up to 2 kbars. Using these liquidus and solidus data and other published information, a thermodynamic-PTX analysis of solid-liquid equilibria at high pressures and temperatures for the ternary system has been performed and is presented in an accompanying paper (Part V of this series). However, all experimental liquidus, solidus, and solvus data used in this analysis are summarized in this report (Part IV) and they are compared with the calculated values based on the analysis. ?? 1992.

Chou, I. -M.; Sterner, S. M.; Pitzer, K. S.

1992-01-01

154

Multicomponent diffusion in molten LiCl-KCl: dynamical correlations and divergent Maxwell-Stefan diffusivities.  

PubMed

Multicomponent diffusional mechanisms in the ternary LiCl-KCl system are elucidated using the Green-Kubo formalism and equilibrium molecular dynamics simulations. The Maxwell-Stefan (MS) diffusion matrix is evaluated from the Onsager dynamical matrix that contains the diffusion flux correlation functions. From the temporal behavior of the correlation functions, we observe that the Li-Li and Li-Cl ion pairs have a pronounced cage dynamics that remains noticeably strong even at high temperatures. Even though the Onsager coefficients, which are the time integrals of the diffusion flux correlation functions, portray a relatively smooth variation across various compositions and temperatures, we observe a sign change and a divergent-like behavior for the MS diffusivity of the K-Li ion pair at a temperature of ~1100 K for the eutectic composition, and at a KCl mole fraction of ~0.49 at 1043 K. Negative MS diffusivities, while unusual, are however shown to satisfy the nonnegative entropic constraints. PMID:23767545

Chakraborty, Brahmananda; Wang, Jin; Eapen, Jacob

2013-05-30

155

A simplified model of TiH1.65/KClO4 pyrotechnic ignition.  

SciTech Connect

A simplified model was developed and is presented in this report for simulating thermal transport coupled with chemical reactions that lead to the pyrotechnic ignition of TiH1.65/KClO4 powder. The model takes into account Joule heating via a bridgewire, thermal contact resistance at the wire/powder interface, convective heat loss to the surroundings, and heat released from the TiH1.65- and KClO4-decomposition and TiO2-oxidation reactions. Chemical kinetic sub-models were put forth to describe the chemical reaction rate(s) and quantify the resultant heat release. The simplified model predicts pyrotechnic ignition when heat from the pyrotechnic reactions is accounted for. Effects of six key parameters on ignition were examined. It was found that the two reaction-rate parameters and the thermal contact resistance significantly affect the dynamic ignition process whereas the convective heat transfer coefficient essentially has no effect on the ignition time. Effects of the initial/ambient temperature and electrical current load through the wire are as expected. Ignition time increases as the initial/ambient temperature is lowered or the wire current load is reduced. Lastly, critical needs such as experiments to determine reaction-rate and other model-input parameters and to measure temperature profiles, time to ignition and burn-rate data for model validation as well as efforts in incorporating reaction-rate dependency on pressure are pointed out.

Chen, Ken Shuang

2009-04-01

156

Vacuum evaporation of KCl-NaCl salts. Part 1: Thermodynamic modeling of vapor pressures of solid and liquid solutions  

SciTech Connect

In electrorefining to purify plutonium scraps and alloys, typically an equal molar KCl-NaCl mixture is used as the molten electrolyte through which the oxidized Pu ions are transported to the cathode where the pure plutonium is produced and settles by gravity to the bottom of the molten salt. In molten salt extraction, molten KCl-NaCl salt or KCl-NaCl salt containing MgCl{sub 2} is used to extract Am from molten Pu. Over the years the spent salts from these processes have accumulated in substantial quantities throughout various Pu processing sites. A promising way to reduce storage space and disposal cost is by first converting the actinide species in the waste salts to oxides through oxygen sparging and then separating the salts from the actinides via a vacuum evaporation process. The separation is possible because of the large difference in the vapor pressure between the chloride salts and the actinide oxides. To aid the optimization of this evaporation separation process and process equipment design, an effort to model the evaporation-condensation process of molten KCl-NaCl solutions was initiated. This article presents the first part of the modeling work in developing vapor pressure relations of the KCl-NaCl system. The methodology of using fundamental thermodynamic relations and data to model the vapor pressure equations for the solid and liquid solutions of the KCl-NaCl system will be presented, and the vapor pressures calculated from the model equation will be compared with the available experimental data. How the model equations are useful in predicting condensate compositions will also be discussed.

Wang, L.L.; Wallace, T.C. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

1996-02-01

157

Development and study of cement and a phosphocalciques ceramic as medical use  

NASA Astrophysics Data System (ADS)

The hydroxyapatite (Ca{10}(PO{4})6(OH){2}) has a structure and a chemical composition very close to those of the mineral phase of calcified tissues. It is thus used for a long time in orthopedic and odontological surgery. In the past few years, cements which evolve toward the hydroxyapatite have been the object of several studies. This communication reports the synthesis and the study of new phosphocalcic cement, which evolves after hardening, towards a hydroxyapatite. The cement is composed of tricalcium phosphate a type (? -Ca{3}(PO{4})2), calcium hydroxide (Ca(OH){2}) and phosphoric acid (H{3}PO{4}). The sintering of hardened cement, leads to ceramics having a structure and chemical composition close to those of the bone's mineral phase. The trisodium phosphate is used as melting agent to increase the hardness of ceramics and to decrease the sintering temperature, without affecting the physicochemical properties of ceramics.

Abbaoui, E.; Essaddek, A.; Mejdoubi, E.; Elansari, L. L.; Elgadi, M.; Hammouti, B.

2005-03-01

158

Phase relations in the system NaCl-KCl-H2O. Part I: Differential thermal analysis of the NaCl-KCl liquidas at 1 atmosphere and 500, 1000, 1500, and 2000 bars  

USGS Publications Warehouse

A simple differential thermal analysis (DTA) technique has been developed to study phase relations of various chemical systems at elevated pressures and temperatures. The DTA system has been calibrated against known melting temperatures in the system NaCl-KCl. Isobaric sections of the liquidus in the system NaCl-KCl have been determined at pressures of 1 atmosphere and 500, 1000, 1500, and 2000 bars. Using the least-squares method, the following equation was used to fit the experimental data: T(??C)= ??? i=0 6aiXiKCl where T is the liquidus temperature, XKCl is mole fraction of KCl, and ai (listed below) are the derived empirical constants. {A table is presented}. The liquidus temperatures estimated from these equations are within ??3??C of experimental values. The measured liquidus temperatures at 1 atmosphere agree with the best available data to within 5??C. The melting temperatures for pure end members at higher pressures agree with the values calculated from the Simon equation (Clark, 1959) to within 3??C. No previous melting data are available for the intermediate compositions at elevated pressures. Using the data in both heating and cooling scans, the minimum melting temperature at 1 atmosphere in the system was located at 658?? ?? 3??C where the sample has an equimolar composition. ?? 1982.

Chou, I. -M.

1982-01-01

159

Physical Chemistry of Molten Salt Batteries. Final Report for Period October 1, 1979-September 30, 1980. Current-Induced Composition Gradients in Molten LiCl-KCl.  

National Technical Information Service (NTIS)

Current induced composition gradients were demonstrated in the molten LiCl-KCl eutectic mixture, the electrolyte of an LiAl/LiCl-KCl/FeS/sub x/ battery. The gradients were produced by electrolysis of the salt between LiAl electrodes at currents of 50 to 1...

J. Braunstein S. Cantor C. E. Vallet

1981-01-01

160

Characterization of Nano-Hydroxyapatite Synthesized from Sea Shells Through Wet Chemical Method  

NASA Astrophysics Data System (ADS)

Nano-hydroxyapatite (HA) was synthesized by a wet chemical reaction using powdered sea shells (CaO) as starting material which was converted to calcium hydroxide (Ca(OH)2) and subsequently reacted with phosphoric acid (H3PO4). Initially raw sea shells (CaCO3) were thermally converted to amorphous calcium oxide by heat treatment. Two sets of experiments were done; in the first experiment, HA powder was dried in an electric furnace and in the second experiment, the reactants were irradiated in a domestic microwave oven followed by microwave drying. In each set of experiments, the concentrations of the reactants were decreased gradually. HA was synthesized by slow addition of phosphoric acid (H3PO4) in to calcium hydroxide (Ca(OH)2) maintaining the pH of the solution at 10 to avoid the formation of calcium deficient apatites. In both the experiments, Ca:P ratio of 1.67 was maintained for the reagents. The synthesized samples showed X-ray diffraction (XRD) patterns corresponding to hydroxyapatite. The wet chemical process with furnace drying resulted in HA particles of size 7-34 nm, whereas microwave irradiated process yielded HA particles of size 34-102 nm as evidenced from XRD analyses. The above experimental work done by wet chemical synthesis to produce HA powder from sea shells is a simple processing method at room temperature. Microwave irradiation leads to uniform crystallite sizes as evident from this study, at differing concentrations of the reactants and is a comparatively easy method to synthesize HA. The high resolution scanning electron microscopy (HRSEM)/transmission electron microscopic (TEM) analyses revealed the characteristic rod-shaped nanoparticles of HA for the present study.

Santhosh, S.; Prabu, S. Balasivanandha

2012-10-01

161

Novel type of neutron image plates based on KCl:Eu2+-LiF  

NASA Astrophysics Data System (ADS)

Neutron image plates (NIP) provide a mean for the two-dimensional, position-sensitive detection of neutrons. They combine the advantages of a large dynamic range (up to 5 orders of magnitude), good spatial resolution (<=300?m) and large detection areas. NIPs are used at various instruments for powder or single-crystal diffraction in numerous radiation facilities. They have also found an application in neutron radiography and can be used for small-angle neutron scattering (SANS) such as at the Structure Powder DIffractometer (SPODI) at the FRM-II. In this study, the resolution of a novel type of ceramic NIPs based on KCl:Eu2+-LiF is presented and simulations on the applicability of NIPs for neutron detection at the SANS apparatus of SPODI are reported.

Schlapp, M.; Hoelzel, M.; Gilles, R.; Ioffe, A.; Brueckel, T.; Fuess, H.; Seggern, H. Von

2004-07-01

162

Corrosion resistance of steel materials in LiCl-KCl melts  

NASA Astrophysics Data System (ADS)

The corrosion behaviors of 304SS, 316LSS, and Q235A in LiCl-KCl melts were investigated at 450°C by Tafel curves and electrochemical impedance spectroscopy (EIS). 316LSS shows the best corrosion resistance behaviors among the three materials, including the most positive corrosion potential and the smallest corrosion current from the Tafel curves and the largest electron transfer resistance from the Nyquist plots. The results are in good agreement with the weight losses in the static corrosion experiments for 45 h. This may be attributed to the better corrosion resistance of Mo and Ni existing as alloy elements in 316LSS, which exhibit the lower corrosion current densities and more positive corrosion potentials than 316LSS in the same melts.

Wang, Le; Li, Bing; Shen, Miao; Li, Shi-yan; Yu, Jian-guo

2012-10-01

163

The formation of tin oxides in thin-film Sn/C/KCl(100) structures  

SciTech Connect

The formation of oxides upon the thermal annealing (both in air and vacuum) of island tin films grown on a KCl(100) substrate, which was coated by a thin layer of amorphous carbon, has been investigated by transmission electron microscopy. It is established that thermal annealing at temperatures below the tin melting point (T{sub m}) does not lead to phase transitions with the formation of new crystalline oxide phases. At the same time, the films undergo structural changes: the average size of blocks in the substrate plane decreases compared to those in an as-deposited film. Thermal annealing in air at temperatures above the tin melting point leads to the formation of multiphase oxide structures and increases the average size of blocks and islands in the substrate plane. It is shown that preliminary thermal annealing in air at temperatures below T{sub m} hinders oxidation upon subsequent heat treatment.

Yurakov, Yu. A., E-mail: ftt@phys.vsu.ru; Ryabtsev, S. V.; Chuvenkova, O. A.; Domashevskaya, E. P.; Nikitenko, A. S. [Voronezh State University (Russian Federation); Kannykin, S. V.; Kushchev, S. B., E-mail: kusheev@phis.vorstu.ru [Voronezh State Technical University (Russian Federation)

2009-01-15

164

Complexes responsible for ionic transport in LiCl-KCl eutectic melt  

SciTech Connect

DFT calculations using DMol software at the DNP/UHF/BLYP level were firstly performed in order to determine the more stable isolated chloro-complexes of lithium and/or potassium cations. An Inverse Isotropic Monte Carlo technique was then used for obtaining a 3-D model of this melt from the pair correlation functions computed by Lantelme and Turq. At last, DFT calculation derived complexes were looked for in the melt model using a lab-made software. This procedure showed the presence of LiCl{sub 2{sup {minus}}} and K{sub 2}Cl{sup +} complexes in molten KCl eutectic. This procedure allows a better understanding of the structure of melt and suggests answers to some phenomena that occur in molten salts such as the Chemla effect. {copyright} {ital 1996 American Institute of Physics.}

Hebant, P.; Picard, G.S. [Laboratoire d`Electrochimie et de Chimie Analytique (URA 216), Ecole Nationale Superieure de Chimie de Paris, 11 rue P & M Curie, 75231 Paris Cedex 05 (France); Mouron, L.; Legendre, J. [Laboratoire de Modelisation Appliquee a la Chimie]|[Ecole Nationale Superieure de Chimie de Paris, 11 rue P & M Curie, 75231 Paris Cedex 05 (France)

1996-04-01

165

Thermodynamic properties of iron and nickel chloride solutions in molten LiCl-KCl  

SciTech Connect

The thermodynamic properties of solutions of iron or nickel chlorides in mixed molten LiCl-KCl were determined by emf measurements of FeCl{sub 2} or NiCl{sub 2} formation cells. The concentration range examined was 0.015-2 mol %. The temperature dependence of the emf between 355 and 540{degree}C was used to calculate the enthalpy and entropy of formation of dissolved FeCl{sub 2} or NiCl{sub 2}. It was shown that, in the investigated concentration range, these solutions have a nearly ideal behavior. Simple empirical equations were derived to represent the emf of these formation cells with an accuracy of about {plus minus} 1.5 mV.

Lantelme, F.; Chemla, M. (Universite Pierre et Marie Curie, Paris (France)); Equey, J.F.; Mueller, S. (Paul Scherrer Institut, Villigen (Switzerland))

1991-01-24

166

Plutonium chemical properties in NaCl KCl and CaCl2 at 1073 K  

NASA Astrophysics Data System (ADS)

The electrochemical properties of plutonium have been studied in molten equimolar NaCl/KCl and CaCl2 at 1073 K by cyclic voltammetry. The respective standard potentials of Pu(III)/Pu redox couple, -2.54 V and -2.51 V (versus Cl-/Cl2 reference electrode), led to the calculation of the activity coefficients of Pu(III) in each electrolyte. In CaCl2 the complexation of Pu(III) ions is lower and the voltage gap between Pu(III)/Pu redox system and the solvent limit is higher. Use of these results to construct potential pO2- diagrams for plutonium at 1073 K gives a rational overview of plutonium properties in these media.

Lambertin, David; Ched'Homme, Séverine; Bourgès, Gilles; Sanchez, Sylvie; Picard, Gérard

2005-05-01

167

Dielectron production in Ar + KCl collisions at 1.76A GeV  

NASA Astrophysics Data System (ADS)

We present results on dielectron production in 40Ar+KCl collisions at 1.76A GeV. For the first time ? mesons could be reconstructed in a heavy-ion reaction at a bombarding energy which is well below the production threshold in free nucleon-nucleon collisions. The ? multiplicity has been extracted and compared to the yields of other particles, in particular of the ? meson. At intermediate e+e- invariant masses, we find a strong enhancement of the pair yield over a reference spectrum from elementary nucleon-nucleon reactions, suggesting the onset of nontrivial effects of the nuclear medium. Transverse-mass spectra and angular distributions have been reconstructed in three invariant mass bins. In the former unexpectedly large slopes are found for high-mass pairs. The latter, in particular the helicity-angle distributions, are largely consistent with expectations for a pair cocktail dominated at intermediate masses by ? Dalitz decays.

Agakishiev, G.; Balanda, A.; Belver, D.; Belyaev, A.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Epple, E.; Fabbietti, L.; Fateev, O.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Gilardi, C.; Golubeva, M.; González-Díaz, D.; Guber, F.; Gumberidze, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Huck, P.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kotte, R.; Krása, A.; Krizek, F.; Krücken, R.; Kuc, H.; Kühn, W.; Kugler, A.; Kurepin, A.; Lang, S.; Lange, J. S.; Lapidus, K.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Morinière, E.; Mousa, J.; Müntz, C.; Naumann, L.; Otwinowski, J.; Pachmayer, Y. C.; Palka, M.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Wagner, V.; Weber, M.; Wendisch, C.; Wisniowski, M.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y.

2011-07-01

168

The Equilibrium Between Titanium Ions and Titanium Metal in NaCl-KCl Equimolar Molten Salt  

NASA Astrophysics Data System (ADS)

The equilibrium between metallic titanium and titanium ions, 3Ti2+ ? 2Ti3+ + Ti, in NaCl-KCl equimolar molten salt was reevaluated. At a fixed temperature and an initial concentration of titanium chloride, the equilibrium was achieved by adding an excess amount of sponge titanium in assistant with bubbling of argon into the molten salt. The significance of this work is that the accurate concentrations of titanium ions have been obtained based on a reliable approach for taking samples. Furthermore, the equilibrium constant {{K}}_{{C}} = (x_{{{{Ti}}^{{ 3 { + }}} }}^{{eql}} )3 /(x_{{{{Ti}}^{{ 2 { + }}} }}^{{eql}} )2 was calculated through the best-fitting method under the consideration of the TiOCl dissolution. Indeed, the final results have disclosed that the stable value of KC could be achieved based on all modifications.

Wang, Qiuyu; Song, Jianxun; Hu, Guojing; Zhu, Xiaobo; Hou, Jungang; Jiao, Shuqiang; Zhu, Hongmin

2013-05-01

169

Effects of various dopants on NaCl and KCl glow curves  

NASA Astrophysics Data System (ADS)

We have measured the thermoluminescence of a number of NaCl and KCl crystals following irradiation at ambient temperature with the same dose (10 kGy) of Co-60 ? rays. We compare the TL of pure samples and of samples doped with europium and calcium ions. In the case of NaCl, additional impurities (Ni, Pb, Sr and Cr) have been investigated. The effects of irradiation are determined using optical absorption and thermoluminescence. Factors investigated include the effects of different dopants on TL glow curves and the effects of thermal annealing samples at 400 °C before the irradiation. Changes in TL glow curves relating to changes in the state of aggregation of the impurities produced by pre-irradiation annealing are reported in this paper. Perhaps the most significant effect is a temperature shift of the main glow peak in pre-annealed compared to not pre-annealed samples in the case of Eu doped NaCl. The magnitude of the shift depends on the concentration of the Eu dopant. Shifts are also observed for Ni and Sr impurities in NaCl, but not for Ca and Cr impurities in NaCl. In the case of KCl, glow peaks generally occur at similar temperatures in doped samples and do not shift when doped samples are pre-annealed. Here the main effect of different impurities is to influence the size of the emission and not the structure of the glow curve. Results are discussed in terms of current theories of thermoluminescence.

Davidson, A. T.; Kozakiewicz, A. G.; Derry, T. E.; Comins, J. D.; Suszynska, M.

2004-06-01

170

Comparative SO2 Reactivity of CaO Derived from CaCO3 and Ca(OH)2.  

National Technical Information Service (NTIS)

In an effort to develop a low-cost retrofit technology for control of sulfur dioxide (SO2) emissions from coal-fired utility plants, boiler injection of dry calcium-based sorbents to form calcium sulfate (CaSo4) has been widely studied. The effects of suc...

B. K. Gullett K. R. Bruce L. O. Beach

1989-01-01

171

The gasification of wet biomass using Ca(OH) 2 as CO 2 absorbent: The microstructure of char and absorbent  

Microsoft Academic Search

Aimed at the hydrogen production by gasification of wet biomass coupled CO2 absorption, the microstructures of chars produced from gasification of wet\\/pre-dried biomass and several possible stages of absorbent were studied with N2 adsorption, XRD and SEM. The results show that all the chars examined have essentially microporous structures of pore size less than 2nm, and the char obtained from

Hu Guoxin; Huang Hao; Li Yanhong

2008-01-01

172

Growth and Structure of Thin Chromium Films Condensed on UltraHigh Vacuum Cleaved NaCl and KCl Crystals  

Microsoft Academic Search

It has been shown that during the growth of thin Cr films condensed on Ultrahigh Vacuum cleaved NaCl and KCl crystals a New Modification of Cr (NMCr) appears, probably as a growth phase. On both substrates the NMCr appears in oriented structures closely related to the orientations of the substrate surface. Electron diffraction patterns caused by the NMCr can be

J. Forssell; B. Persson

1970-01-01

173

Elaboration and characterization of a KCl single crystal doped with nanocrystals of a Sb2O3 semiconductor  

NASA Astrophysics Data System (ADS)

Undoped and doped KCl single crystals have been successfully elaborated via the Czochralski (Cz) method. The effects of dopant Sb2O3 nanocrystals on structural and optical properties were investigated by a number of techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDAX) analysis, UV-visible and photoluminescence (PL) spectrophotometers. An XRD pattern of KCl:Sb2O3 reveals that the Sb2O3 nanocrystals are in the well-crystalline orthorhombic phase. The broadening of diffraction peaks indicated the presence of a Sb2O3 semiconductor in the nanometer size regime. The shift of absorption and PL peaks is observed near 334 nm and 360 nm respectively due to the quantum confinement effect in Sb2O3 nanocrystals. Particle sizes calculated from XRD studies agree fairly well with those estimated from optical studies. An SEM image of the surface KCl:Sb2O3 single crystal shows large quasi-spherical of Sb2O3 crystallites scattered on the surface. The elemental analysis from EDAX demonstrates that the KCl:Sb2O3 single crystal is slightly rich in oxygen and a source of excessive quantities of oxygen is discussed.

Bouhdjer, L.; Addala, S.; Chala, A.; Halimi, O.; Boudine, B.; Sebais, M.

2013-04-01

174

Phase formation in the LiCl-LiNO3-KCl-Sr(NO3)2 system  

NASA Astrophysics Data System (ADS)

The LiCl-LiNO3-KCl-Sr(NO3)2 four-component system was studied for the first time by a complex of physicochemical analysis methods, including differential thermal analysis, X-ray diffraction, visual-polythermal, and projection thermographic methods. Eutectic and peritectic invariant point characteristics were determined, and the phase diagram of the system was constructed.

Gasanaliev, A. M.; Gamataeva, B. Yu.; Umarova, Yu. A.

2012-04-01

175

Industrial Applications of Powder X-Ray Diffraction Analysis to the TiH(x)-KClO4 Pyrotechnic System.  

National Technical Information Service (NTIS)

Powder x-ray diffraction techniques were utilized in the evaluation of locally synthesized TiH/sub x/ materials to assist in evolving the best method for preparing such hydride materials, in the production of baseline data for TiH/sub x/ and KClO sub 4 st...

D. B. Sullenger R. R. Eckstein R. S. Carlson

1976-01-01

176

Influences on the ?-muscle-spindle system from contralateral muscle afferents stimulated by KCl and lactic acid  

Microsoft Academic Search

The aim of the present study was to investigate whether increased concentrations of lactic acid and potassium chloride (KCl) in contralateral muscles can influence the sensitivity of primary and secondary muscle spindle afferents (MSAs) from ipsilateral extensor and flexor muscles. The experiments were performed on 7 cats anaesthetised with ?-chloralose. Recordings were made simultaneously from 2–12 single MSAs from the

Mats Djupsjöbacka; Håkan Johansson; Mikael Bergenheim; Per Sjölander

1995-01-01

177

Formation of Pb during epitaxial growth of PbS on KCl in a vitreous silica hot wall system  

Microsoft Academic Search

Thin monocrystalline films of PbS grown epitaxially from the vapour on KCl in a vitreous silica hot wall system, present lower specular reflectivity than expected. Electron micrography shows that the surfaces of the films are studded with a multitude of small blobs. They scatter partially the incident light. By electron probe microanalysis and Bragg diffractometry it was found that the

M. Paic; V. Pai?

1972-01-01

178

Electrochemical extraction of neodymium by co-reduction with aluminum in LiCl-KCl molten salt  

NASA Astrophysics Data System (ADS)

The electrochemical behavior of Nd(III) ions in LiCl-KCl and LiCl-KCl-AlCl3 melts on a Mo electrode at 723 K was studied by various electrochemical techniques. The results showed that Nd(III) ions are reduced to Nd(0) through two consecutive steps, and the underpotential deposition of neodymium on pre-deposited Al electrode formed two kinds of Al-Nd intermetallic compounds in LiCl-KCl-AlCl3 solutions. The electrochemical extraction of neodymium was carried out in LiCl-KCl-AlCl3 melts on a Mo electrode at 873 K by potentiostatic and galvanostatic electrolysis. The extraction efficiency was 99.25% after potentiostatic electrolysis for 30 h. Al-Li-Nd bulk alloy was obtained by galvanostatic electrolysis. X-ray diffraction (XRD) suggested that Al2Nd and Al3Nd phases were formed in Al-Li-Nd alloy. The microstructure and micro-zone chemical analysis of Al-Li-Nd alloy were characterized by scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), respectively.

Yan, Yong-De; Xu, Yan-Lu; Zhang, Mi-Lin; Xue, Yun; Han, Wei; Huang, Ying; Chen, Qiong; Zhang, Zhi-Jian

2013-02-01

179

Off-center effect on the diffusion coefficient of Cu(sup +) and Li(sup +) in the KCl lattice.  

National Technical Information Service (NTIS)

It is well known that the diffusion coefficients of the Cu(sup +) cation in the NaCl and KCl lattices exceeds by three or four orders of magnitude the corresponding self-diffusion coefficients in the intrinsic temperature regions. This fast diffusion of t...

F. Despa

1994-01-01

180

Brownian Migration of Crystallites on a Surface the Case of Aluminum on Kcl Clarification of the Slip Mechanism, Part 3.  

National Technical Information Service (NTIS)

It is shown experimentally that crystallites of aluminum are able to migrate on a (100) KCl substrate (contact plane (111)). The measurements give a free activation enthalpy of their diffusion which contains a term Delta G sub 0 which is independent of th...

J. J. Metois M. Gauch A. Masson R. Kern

1972-01-01

181

Volume changes and potential artifacts of epithelial cells of frog skin following impalement with microelectrodes filled with 3 m KCl  

Microsoft Academic Search

Summary  Cells of isolated frog skin epithelium were observed microscopically during impalement with standard microelectrodes of 5 to 20 M resistance, filled with 3m KCl. Impaled cells, as well as some neighboring cells, were seen to swell 10 to 100 sec after impalement, while the negative potential recorded by the microelectrode depolarized (open circuit conditions). Apparently, osmotic swelling of small epithelial

D. J. Nelson; J. Ehrenfeld; B. Lindemann

1978-01-01

182

Determination of Effective Conductivity of Porous Ceramic Separators of LiAl/LiCl-KCl/FeS Cells.  

National Technical Information Service (NTIS)

High-temperature (450 exp 0 C) lithium-aluminum/iron sulfide cells containing LiCl-KCl electrolyte are currently under development at Argonne National Laboratory (ANL). In this type of cell, electrodes are usually made by pressing mixtures of active mater...

H. Ohno H. Shimotake

1980-01-01

183

Corrosion and Microstructure Correlation in Molten LiCl-KCl Medium  

NASA Astrophysics Data System (ADS)

Pyrochemical reprocessing in molten chloride salt medium has been considered as one of the best options for the reprocessing of spent metallic fuels of future fast breeder reactors. The unit operations such as salt preparation, electrorefining, and cathode processing involve the presence of molten LiCl-KCl eutectic salt from 673 to 1373 K (400 to 1100 °C). The present work discusses the corrosion behavior of electroformed nickel (EF Ni) without and with nickel-tungsten (Ni-W) coating, 316L SS, and INCONEL 625 alloy in molten LiCl-KCl eutectic salt at 673 K, 773 K, and 873 K (400 °C, 500 °C, and 600 °C) in the presence of air. The weight percent loss of the exposed samples was determined by the weight loss method and surface morphology of the salt exposed, and product layers were examined by scanning electron microscopy (SEM). X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analysis were also carried out on the exposed and corrosion product layers to understand the phases present and the corrosion mechanism involved. The results of the present study indicated that INCONEL 625 alloy showed superior corrosion resistance compared to electroformed nickel (EF Ni), EF Ni with nickel-tungsten (Ni-W) coating (EF Ni-W), and 316L SS. The EF Ni with Ni-W coating exhibits better corrosion resistance than EF Ni without tungsten coating. Based on the surface morphology, XRD, and EDX analysis of corrosion product layers, the mechanism of corrosion of INCONEL 625 and 316L involves formation of chromium-rich compound at the surface and subsequent spallation. For the EF Ni, the porous thick NiO corrosion product allows the penetration of salt, thus accelerating the corrosion. Improved corrosion resistance of EF Ni-W was attributed to the W-rich NiO layer, while for INCONEL 625, the adherent and protective NiO layer improved the corrosion resistance. The article highlights the results of the present investigation.

Ravi Shankar, A.; Mathiya, S.; Thyagarajan, K.; Kamachi Mudali, U.

2010-07-01

184

Swelling activation of K-Cl cotransport in LK sheep erythrocytes: a three-state process  

PubMed Central

K-Cl cotransport in LK sheep erythrocytes is activated by osmotic swelling and inhibited by shrinkage. The mechanism by which changes in cell volume are transduced into changes in transport was investigated by measuring time courses of changes in transport after osmotic challenges in cells with normal and reduced Mg concentrations. When cells of normal volume and normal Mg are swollen, there is a delay of 10 min or more before the final steady-state flux is achieved, as there is for swelling activation of K-Cl cotransport in erythrocytes of other species. The delay was shown to be independent of the extent of swelling. There was also a delay after shrinkage inactivation of cotransport. Reducing cellular Mg concentration activates cotransport. Swelling of low-Mg cells activates cotransport further, but with no measurable delay. In contrast, there is a delay in shrinkage inactivation of cotransport in low-Mg cells. The results are interpreted in terms of a three-state model: [formula see text] in which A state, B state, and C state transporters have relatively slow, intermediate, and fast transport rates, respectively. Most transporters in shrunken cells with normal Mg are in the A state. Swelling converts transporters to the B state in the rate-limiting process, followed by rapid conversion to the C state. Reducing cell Mg also promotes the A-- >B conversion. Swelling of low-Mg cells activates transport rapidly because of the initial predominance of B state transporters. The results support the following conclusions about the rate constants of the three-state model: k21 is the rate constant for a Mg-promoted process that is inhibited by swelling; k12 is not volume sensitive. Both k23 and k32 are increased by swelling and reduced by shrinkage; they are rate constants for a single process, whereas k12 and k21 are rate constants for separate processes. Finally, the A-->B conversion entails an increase in Jmax of the transporters, and the B-->C conversion entails an increase in the affinity of the transporters for K.

1993-01-01

185

Measurement of standard potentials of actinides (U,Np,Pu,Am) in LiCl–KCl eutectic salt and separation of actinides from rare earths by electrorefining  

Microsoft Academic Search

Pyrochemical separation of actinides from rare earths in LiCl–KCl eutectic–liquid metal systems has been studied. The electromotive forces of galvanic cells of the form, Ag|Ag(I), LiCl–KCl?actinide(III), LiCl–KCl|actinide, were measured and standard potentials were determined for uranium, neptunium and plutonium to be ?1.283 V, ?1.484 V and ?1.593 V (at 450°C vs. Ag\\/AgCl (1wt%–AgCl)), respectively. A typical cyclic voltammogram of americium

Y. Sakamura; T. Hijikata; K. Kinoshita; T. Inoue; T. S. Storvick; C. L. Krueger; J. J. Roy; D. L. Grimmett; S. P. Fusselman; R. L. Gay

1998-01-01

186

Protein-salt binding data from potentiometric titrations of lysozyme in aqueous solutions containing KCl  

SciTech Connect

An existing method for potentiometric titrations of proteins was improved, tested and applied to titrations of the enzyme hen-egg-white lysozyme in aqueous solutions containing KCl at ionic strengths from 0.1 M to 2.0 M at 25 C. Information about the protein`s net charge dependence on pH and ionic strength were obtained and salt binding numbers for the system were calculated using a linkage concept. For the pH range 2.5--11.5, the net charge slightly but distinctly increases with increasing ionic strength between 0.1 M and 2.0 M. The differences are most distinct in the pH region below 5. Above pH 11.35, the net charge decreases with increasing ionic strength. Preliminary calculation of binding numbers from titration curves at 0.1 M and 1.0 M showed selective association of chloride anions and expulsion of potassium ions at low pH. Ion-binding numbers from this work will be used to evaluate thermodynamic properties and to correlate crystallization or precipitation phase-equilibrium data in terms of a model based on the integral-equation theory of fluids which is currently under development.

Engmann, J.; Blanch, H.W.; Prausnitz, J.M. [Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering]|[Lawrence Berkeley National Lab., CA (United States). Chemical Sciences Div.

1997-03-01

187

Dielectron production in Ar + KCl collisions at 1.76A GeV  

SciTech Connect

We present results on dielectron production in {sup 40}Ar+KCl collisions at 1.76A GeV. For the first time {omega} mesons could be reconstructed in a heavy-ion reaction at a bombarding energy which is well below the production threshold in free nucleon-nucleon collisions. The {omega} multiplicity has been extracted and compared to the yields of other particles, in particular of the {phi} meson. At intermediate e{sup +}e{sup -} invariant masses, we find a strong enhancement of the pair yield over a reference spectrum from elementary nucleon-nucleon reactions, suggesting the onset of nontrivial effects of the nuclear medium. Transverse-mass spectra and angular distributions have been reconstructed in three invariant mass bins. In the former unexpectedly large slopes are found for high-mass pairs. The latter, in particular the helicity-angle distributions, are largely consistent with expectations for a pair cocktail dominated at intermediate masses by {Delta} Dalitz decays.

Agakishiev, G.; Belyaev, A.; Chernenko, S.; Fateev, O.; Zanevsky, Y. [Joint Institute of Nuclear Research, RU-141980 Dubna (Russian Federation); Balanda, A.; Dybczak, A.; Michalska, B.; Otwinowski, J.; Przygoda, W.; Salabura, P.; Trebacz, R.; Wisniowski, M. [Smoluchowski Institute of Physics, Jagiellonian University of Cracow, PL-30-059 Krakow (Poland); Belver, D.; Cabanelas, P.; Castro, E.; Garzon, J. A. [Departamento de Fisica de Particulas, Univ. de Santiago de Compostela, E-15706 Santiago de Compostela (Spain); Blanco, A.; Fonte, P.; Lopes, L. [LIP-Laboratorio de Instrumentacao e Fisica Experimental de Particulas, P-3004-516 Coimbra (Portugal)

2011-07-15

188

Separation of plutonium from lanthanum by electrolysis in LiCl KCl onto molten bismuth electrode  

NASA Astrophysics Data System (ADS)

This work presents a study on the electroseparation of plutonium from lanthanum using molten bismuth electrodes in LiCl KCl eutectic at 733 K. The reduction potentials of Pu3+ and La3+ ions were measured on a Bi thin film electrode using cyclic voltammetry (CV). A difference between the peak potentials for the formation of PuBi2 and LaBi2 of approximately 100 mV was found. Separation tests were then carried out using different current densities and salt phase compositions between a plutonium rod anode and an unstirred molten Bi cathode in order to evaluate the efficiency of an electrolytic separation process. At a current density of 12 mA/cm2/wt% (Pu3+), only Pu3+ ions are reduced into the molten Bi electrode, leaving La3+ ions in the salt melt. Similar results were found at two different Pu/La concentration ratios ([Pu]/[La] = 4 and 10). At a current density of 26 mA/cm2/wt% (Pu3+), co-reduction of Pu and La was observed as expected by the large negative potential of the Bi cathode during the separation test.

Serp, J.; Lefebvre, P.; Malmbeck, R.; Rebizant, J.; Vallet, P.; Glatz, J.-P.

2005-04-01

189

?-p femtoscopy in collisions of Ar+KCl at 1.76A GeV  

NASA Astrophysics Data System (ADS)

Results on ?p femtoscopy are reported at the lowest energy so far. At a beam energy of 1.76A GeV, the reaction Ar+KCl was studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. A high-statistics and high-purity ? sample was collected, allowing for the investigation of ?p correlations at low relative momenta. The experimental correlation function is compared to corresponding model calculations allowing the determination of the space-time extent of the ?p emission source. The ?p source radius is found to be slightly smaller than the pp correlation radius for a similar collision system. The present ?p radius is significantly smaller than that found for Au+Au/Pb+Pb collisions in the AGS, SPS, and RHIC energy domains but larger than that observed for electroproduction from He. Taking into account all available data, we find the ?p source radius to increase almost linearly with the number of participants to the power of one-third.

Agakishiev, G.; Balanda, A.; Bassini, R.; Belver, D.; Belyaev, A. V.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Braun-Munzinger, P.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; Díaz, J.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Fabbietti, L.; Fateev, O. V.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Golubeva, M.; González-Díaz, D.; Guber, F.; Hennino, T.; Holzmann, R.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kotte, R.; Krizek, F.; Krücken, R.; Kühn, W.; Kugler, A.; Kurepin, A.; Lang, S.; Lange, J. S.; Lapidus, K.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Morinière, E.; Mousa, J.; Müntz, C.; Naumann, L.; Otwinowski, J.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Sudol, M.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Wagner, V.; Weber, M.; Wendisch, C.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y. V.; Zhou, P.; Zumbruch, P.

2010-08-01

190

First-principles super-cell investigation of the rattling effect in Li-doped KCl.  

PubMed

We have studied by the first-principles total energy method the off-center instability of a substitutional Li impurity in KCl. We report here the results of super-cell calculations of the energy associated with displacing the Li along [Formula: see text], [Formula: see text] and [Formula: see text] directions relative to the K vacancy. To understand the influence of relaxations, we performed three levels of relaxations-only first nearest neighbors of the vacancy, first and second nearest neighbors, and full relaxation. Our calculations show that the relaxation significantly affects the energy surface and that the relaxation of the nearest neighbors to the vacancy accounts for most of the trend. The position of minimum energy for the Li was found to be along the [Formula: see text] direction. The calculated well along [Formula: see text] is 102 meV deep relative to the on-center energy and lies about 0.86 Å off-center. Minima along adjacent [Formula: see text] directions are separated by a saddle-point barrier of 44 meV along the [Formula: see text] direction. Our calculated results are in agreement with prior model calculations and we believe our calculated potential surfaces are the best theoretical result so far. PMID:21715802

Gao, Xing; Daw, Murray S

2008-12-15

191

Electrolytic LiCl precipitation from LiCl-KCl melt in porous Li-Al anodes  

NASA Astrophysics Data System (ADS)

Composition gradients such as those predicted to occur during discharge of porous Li-Al negative electrodes of Li/S batteries with LiCl-KCl eutectic electrolyte were generated and measured in the LiCl-KCl anolyte of an electrolysis cell with Li-Al electrodes. Precipitation of lithium chloride during electrolysis was observed by two-dimensional scanning of electrolyte composition in the front part of quenched porous Li-Al anode sections using SEM/EDX. The distribution of sites of increased or decreased LiCl concentration, LiCl saturation and precipitation was mapped. Cathodic regions were observed near the cell walls. Preliminary results of analysis by Auger spectroscopy confirm LiCl precipitation in the porous anode.

Vallet, C. E.; Heatherly, D. E.; Heatherly, L., Jr.; Braunstein, J.

1983-12-01

192

Recycling of LiCl-KCl eutectic based salt wastes containing radioactive rare earth oxychlorides or oxides  

NASA Astrophysics Data System (ADS)

Recycling of LiCl-KCl eutectic salt wastes containing radioactive rare earth oxychlorides or oxides was studied to recover renewable salts from the salt wastes and to minimize the radioactive wastes by using a vacuum distillation method. Vaporization of the LiCl-KCl eutectic salt was effective above 900 °C and at 5 Torr. The condensations of the vaporized salt were largely dependent on temperature gradient. Based on these results, a recycling system of the salt wastes as a closed loop type was developed to obtain a high efficiency of the salt recovery condition. In this system, it was confirmed that renewable salt was recovered at more than 99 wt.% from the salt wastes, and the changes in temperature and pressure in the system could be utilized to understand the present condition of the system operation.

Eun, H. C.; Cho, Y. Z.; Son, S. M.; Lee, T. K.; Yang, H. C.; Kim, I. T.; Lee, H. S.

2012-01-01

193

Decomposition of di-tert-butyl peroxide on the surface of KCl/SiO/sub 2/  

SciTech Connect

A study was carried out on carbon deposition on the surface of 5% KCl/SiO/sub 2/ upon the decomposition of di-tert-butyl peroxide, (DTBP). The EPR spectra of the paramagnetic sites in the carbon deposit depend on the amount of peroxide decomposed. The EPR spectrum of the RO/sub 2/ radicals stabilized on KCl crystals was recorded. Carbonization of the surface as a result of the decomposition of DTBP is responsible for the chemical reactions, including the reactions of adsorbed RO/sub 2/ radicals, the formation of carbon deposits with strongly delocalized electrons in the conductance band, and the reaction of the radicals with localized paramagnetic sites, which should hinder the removal of the radicals from the surface into the gas phase.

Chaltykyan, M.T.; Lazarev, E.G.; Aliev, R.K.; Gazaryan, K.G.; Garibyan, T.A.; Nalbandyan, A.B.; Gencheva, L.; Kotsev, N.K.; Shopov, D.M.

1989-02-01

194

Activity coefficients of actinide and rare-earth chlorides in molten LiCl/KCl eutectic salt  

SciTech Connect

Using a numerical Gibbs free-energy minimization technique, the activity coefficients of actinide and rare-earth chlorides in molten LiCl/KCl eutectic at 450 C have been calculated. Laboratory tests of an electrochemical process for separating actinide metals from rare-earth metals in LiCl/KCl solvent at 450 C provided experimental concentration and cathode potential data. The generalized expansion by Wohl was used to express the concentration dependence of the excess Gibbs free energy. The activity coefficients were expressed in terms of the Wohl volume and interaction energy parameters. The Wohl parameters for the activity coefficient expansions were obtained by minimizing the total Gibbs free energy expressed in terms of the experimental mole fractions. This thermodynamic model will be valuable for process design and scale-up calculations.

Bechtel, T.B.; Storvick, T.S. [Univ. of Missouri, Columbia, MO (United States). Dept. of Chemical Engineering

1999-04-01

195

Preliminary results on the identification of ultraviolet and beta radiation exposure in KCl:Eu2+ single crystals by thermoluminescence  

NASA Astrophysics Data System (ADS)

The thermoluminescence (TL) sensitivity to ionising (beta source) and non-ionising (UV) radiation on KCl:Eu2+ single crystals has been investigated. The different shapes of the TL glow curves allow us to detect specific peaks (over 220-250 °C) due to UV exposure that exhibit a negligible contribution associated with ionising radiation. The UV-induced TL emission could be deconvoluted into five groups of components peaked at about 120, 150, 210, 250 and 330 °C assuming first order kinetic processes. Dose saturation and linearity region have been determined for a wavelength of 254.7 nm. The effect of several cycles of UV irradiation processes on the linearity of the high energy ultraviolet KCl:Eu2+ dosimeter has been also studied to determine the potential reusability.

Aguirre de Carcer, I.; Correcher, V.; Barboza-Flores, M.; D'Antoni, H. L.; Jaque, F.

2009-09-01

196

Electromotive force responses of Cl[sub 2] gas sensor using BaCl[sub 2]-KCl solid electrolyte  

SciTech Connect

Chlorine is the most important halogen in industrial production. Chlorine exhaust gas has become a serious problem with regard to air pollution and acid rain in recent years. Solid electrolyte-type gas sensors are superior for SO[sub x] or CO[sub 2] detection because of their rapid response. A Cl[sub 2] gas sensor using BaCl[sub 2]-KCl solid electrolyte was investigated. The conductivity was greatly enhanced by KCl doping of the (1 [minus] x)BaCl[sub 2][minus]x KCl system, and a maximum conductivity of 5.6 [times] 10[sup [minus]5]S [times] cm[sup [minus]1] at 573 K was obtained for x = 0.02. The sensor probe was prepared by a melting method at 1,373 K. The electromotive force (EMF) measurement with the Cl[sub 2] gas sensor using the 0.97BaCl[sub 2]-0.03KCl solid electrolyte was performed with an Ag-AgCl solid reference electrode and an RuO[sub 2] measuring electrode. Good agreement between the measured and the calculated EMF values was obtained for Cl[sub 2] gas concentrations from 50 to 10,000 ppm at 623 K. The EMF response time with a change in Cl[sub 2] concentration is ca. 1 min for above 100 ppm and 2 to 5 min for lower concentrations. The measured EMF was not influenced by O[sub 2] or CO[sub 2] gas concentration. This sensor probe was very stable in the presence of water vapor at 623 K during a 90 day test period.

Aono, Hiromichi; Sugimoto, Eisuke (Niihama National Coll. of Technology, Ehime (Japan). Dept. of Industrial Chemistry); Mori, Yoshiaki; Okajima, Yasuhiro (Sumitomo Metal Mining Co., Ltd., Ehime (Japan). Niihama Research Lab.)

1993-11-01

197

Ion-pair Formation and Ion Mobilities in Aqueous NaCl and KCl at High Temperatures from Conductance Data  

Microsoft Academic Search

The electrical conductivity of aqueous solutions of NaCl have been measured at 651 K and 670 K at 28 MPa for molalities up to 1.0 mol\\/kg. These conductivities plus the results of Hwang et al.(1970), Ritzert and Franck (1968), and Mangold and Franck (1969) for aqueous KCl have been fit to the conductance equation of Turq, et al. (1995) with

V. N. Balashov; R. H. Wood; A. V. Sharygin; G. H. Zimmerman

2001-01-01

198

Effect of KCl-medium on succinate oxidation and hydrogen peroxide generation in mitochondria of sugar beet taproot  

Microsoft Academic Search

The effect of substitution of KCl for sucrose in the reaction medium on succinate oxidation and hydrogen peroxide generation\\u000a was investigated in the mitochondria isolated from stored taproots of sugar beet (Beta vulgaris L.). In a sucrose-containing medium, oxidation of succinate was inhibited by oxaloacetate; this inhibition was especially\\u000a pronounced upon a decrease in substrate concentration and eliminated in the

A. G. Shugaev; N. A. Shugaeva; D. A. Lashtabega; E. I. Vyskrebentseva

2010-01-01

199

Speciation of the vanadium(III)–acetylacetone system in 3.0 M KCl ionic medium at 25°C  

Microsoft Academic Search

A study of the H-acetylacetone (acac, HC) and H–V-acetylacetone systems using emf(H) and UV–Vis measurements in 3.0 M KCl ionic medium at 25°C is presented here. As the initial case, the acetylacetone pKa value was determined under similar experimental conditions as reported a few years ago, finding very similar values. Subsequently, in the study of the H–V-acetylacetone system, the stability

F. Brito; M. L. Araujo; J. D. Martínez; Y. Hernández; A. Moh; V. Lubes

2009-01-01

200

Adsorption of eutectic LiCl-KCl into zeolite 4A using a mechanically fluidized vacuum system  

Microsoft Academic Search

A high-temperature mixer has been used to absorb LiCl-KCl eutectic salt powders into zeolite 4A. In situ sampling has been performed, allowing for a time-resolved view of the adsorption reaction. The weight percent free (nonabsorbed) chloride ions has been used as a measure of the effectiveness of the adsorption process. Using zeolite 4A powder with no binder, the free chloride

Michael F. Simpson; Terry J. Battisti

1999-01-01

201

Interaction Between Aluminum Nitride-Based Composite Materials and a CaCl2 – KCl Eutectic Molten Salt Solution  

Microsoft Academic Search

The interaction between composite materials based on aluminum nitride and a phosphate binder (PB) and a CaCl2 – KCl molten salt solution is studied as a function of time (10 – 220 h) by a gravimetric method. The test specimens studied were sintered (AlN + PB)-based composite, hot-pressed Y2O3-doped aluminum nitride, graphite, and (AlN + PB)-coated graphite. The concentration of

L. B. Khoroshavin; A. R. Beketov; D. A. Beketov; Yu. P. Zaikov; V. V. Chebykin

2002-01-01

202

Influences on the gamma-muscle spindle system from muscle afferents stimulated by KCl and lactic acid.  

PubMed

It is known that accumulation of contraction metabolites in muscles stimulates group III and IV afferents and induces excitation of gamma-efferents to the homonymous muscle. The aim of the present study was to investigate whether increased concentrations of lactic acid and KCl in one muscle may influence the activity in primary and secondary muscle spindle afferents (MSAs) from the chemically affected muscle and from surrounding muscles. The experiments were made on 7 cats anesthetized with alpha-chloralose. Recordings were made simultaneously from 2-8 single MSAs from the triceps surae (GS) and the posterior biceps and semitendinosus muscles (PBSt). The mean rate of firing and the depth of modulation of MSA responses to sinusoidal stretching of the receptor-bearing muscles were determined. Responses of 27 primary MSAs (11 from PBSt and 16 from GS) were recorded. On 24 of these clear-cut alterations in sinusoidal response were evoked by injection of 1 ml of KCl (50-600 mM) or 1 ml of lactic acid (20-200 mM) into the artery supply of the GS muscle. Also, all secondary MSAs recorded (4 from PBSt and 1 from GS) showed sizable effects to increased intramuscular concentrations of KCl and/or lactic acid. On both primary and secondary MSAs, from GS as well as from PBSt muscles, nearly all effects observed were compatible with activation of static fusimotor neurons. Effects on MSAs were completely abolished when the ipsilateral L7-L6 ventral roots were cut and when the GS nerve was anesthetized. Intravenous injections of KCl and lactic acid, as well as arterial injections of 0.9% NaCl, were ineffective in changing the MSA responses.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8387164

Johansson, H; Djupsjöbacka, M; Sjölander, P

1993-01-01

203

Characterization of AgInTe 2 films grown by a hot wall epitaxy technique on KCl substrates  

Microsoft Academic Search

AgInTe2 films have been grown by a hot wall epitaxy technique onto KCl substrates kept at different temperatures in a vacuum of 1.3×10?3 Pa. Experimental conditions were optimized to obtain better crystallinity in the films. The films thus prepared were studied for their electrical conductivity, Hall mobility, carrier concentration, as well as structural and optical properties. Observations reveal that the

Amarjit Singh; R. K Bedi

2001-01-01

204

Growth and properties of aluminium antimonide films produced by hot wall epitaxy on single-crystal KCl  

Microsoft Academic Search

Aluminium antimonide (AlSb) films have been grown by hot wall epitaxy on KCl substrates kept at different temperatures in vacuum of 1 × 10?5 Torr. The experimental conditions are optimised to obtain better crystallinity of the films. The electrical conductivity. Hall mobility and carrier concentration are determined. The films appear to be p-type: thus, indicating holes as dominant charge carriers.

Taminder Singh; R. K. Bedi

1998-01-01

205

Optical Constants and Excition States in KCl Single Crystals. III. The Spectra of Conductivity and of Energy Loss  

Microsoft Academic Search

The spectra of conductivity sigma(E) and of energy loss Im {\\\\varepsilon(E)-1} of KCl single crystals are studied as functions of temperature of the ranged of 10°K to 573°K in the intrinsic region to 12 eV. It is shown that sigma(E)-spectra in the chlorine doublet region can be decomposed in the whole range of temperature into the two components of asymmetric

Tetsuhiko Tomiki

1969-01-01

206

Modeling ATP protonation and activity coefficients in NaCl aq and KCl aq by SIT and Pitzer equations  

Microsoft Academic Search

The acid–base properties of Adenosine 5?-triphosphate (ATP) in NaCl and KCl aqueous solutions at different ionic strengths (0

Concetta De Stefano; Demetrio Milea; Alberto Pettignano; Silvio Sammartano

2006-01-01

207

Luminescent characteristics of pure and Ce doped K2LaCl5 phase in KCl host  

NASA Astrophysics Data System (ADS)

The formation of Ce3+ doped K2LaCl5 microphase has been revealed for the KCl-LaCl3-CeCl3 system. Luminescent characteristics of pure and Ce3+ doped K2LaCl5 microcrystals, embedded in KCl matrix, are studied in comparison with those of bulk K2LaCl5:Ce(0.1%) crystal. For both the micro- and bulk K2LaCl5:Ce crystals the bands peaked at 344 and 373 nm are attributed to Ce3+ emission revealing a 24 ns time constant for the main decay component upon the excitation within the Ce3+ f-d absorption range. The method elaborated for the synthesis of the activated K2LaCl5 microphase in the KCl-LaCl3-CeCl3 system provides the possibility of producing large-size homogeneous scintillation elements possessing efficient emission of rare earth doped A2LaX5 micro- and nano-phases embedded in AX matrices (A = Cs, K, Rb; X = F, Cl, Br, I).

Voloshinovskii, A.; Stryganyuk, G.; Zimmerer, G.; Rodnyi, P.; Antonyak, O.; Myagkota, S.; Savchyn, P.

2005-07-01

208

Electrolysis of uranium nitride containing fission product elements (Mo, Pd, Nd) in a molten LiCl-KCl eutectic  

SciTech Connect

The electrolysis of burnup-simulated uranium nitride, UN, containing representative solid fission product elements (Mo, Pd, Nd) was investigated in the molten LiCl-KCl eutectic salt with 0.54 wt% UCl{sub 3} from the view point of application of pyrochemical reprocessing to nitride fuel cycle. It was found from cyclic voltammetry and anodic polarization curve measurement that anodic dissolution of UN began at about -0.75 V vs. Ag/AgCl reference electrode in all samples. After the electrolysis at the constant anodic potential of -0.65 {approx} -0.60 V vs. Ag/AgCl, most of UN was dissolved into LiCl- KCl as UCl{sub 3} at the anode, and U was recovered in the liquid Cd cathode in all samples. Further, Nd was dissolved into LiCl-KCl as NdCl{sub 3}, while Mo and Pd were not dissolved but remained at the anode. (authors)

Satoh, Takumi; Iwai, Takashi; Arai, Yasuo [Japan Atomic Energy Agency, Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki-ken, 311-1393 (Japan)

2007-07-01

209

Protective roles of bacterioruberin and intracellular KCl in the resistance of Halobacterium salinarium against DNA-damaging agents.  

PubMed

Halobacterium salinarium, a member of the extremely halophilic archaebacteria, contains a C50-carotenoid namely bacterioruberin. We have previously reported the high resistance of this organism against the lethal actions of DNA-damaging agents including ionizing radiation and ultraviolet light (UV). In this study, we have examined whether bacterioruberin and the highly concentrated salts in this bacterium play protective roles against the lethal actions of ionizing radiation, UV, hydrogen peroxide, and mitomycin-C (MMC). The colourless mutant of H. salinarium deficient in bacterioruberin was more sensitive than the red-pigmented wild-type to all tested DNA-damaging agents except MMC. Circular dichroism (CD) spectra of H. salinarium chromosomal DNA at various concentrations of KCl (0-3.5 M) were similar to that of B-DNA, indicating that no conformational changes occurred as a result of high salt concentrations. However, DNA strand-breaks induced by ionizing radiation were significantly reduced by the presence of either bacterioruberin or concentrated KCl, presumably due to scavenging of free radicals. These results suggest that bacterioruberin and intracellular KCl of H. salinarium protect this organism against the lethal effects of oxidative DNA-damaging agents. PMID:10196780

Shahmohammadi, H R; Asgarani, E; Terato, H; Saito, T; Ohyama, Y; Gekko, K; Yamamoto, O; Ide, H

1998-12-01

210

Exploring Io's Atmospheric Composition with APEX: First Measurement of 34SO2 and Tentative Detection of KCl  

NASA Astrophysics Data System (ADS)

The composition of Io's tenuous atmosphere is poorly constrained. Only the major species SO2 and a handful of minor species have been positively identified, but a variety of other molecular species should be present, based on thermochemical equilibrium models of volcanic gas chemistry and the composition of Io's environment. This paper focuses on the spectral search for expected yet undetected molecular species (KCl, SiO, S2O) and isotopes (34SO2). We analyze a disk-averaged spectrum of a potentially line-rich spectral window around 345 GHz, obtained in 2010 at the APEX 12 m antenna. Using different models assuming either extended atmospheric distributions or a purely volcanically sustained atmosphere, we tentatively measure the KCl relative abundance with respect to SO2 and derive a range of 4 × 10-4-8 × 10-3. We do not detect SiO or S2O and present new upper limits on their abundances. We also present the first measurement of the 34S/32S isotopic ratio in gas phase on Io, which appears to be twice as high as the Earth and interstellar medium reference values. Strong lines of SO2 and SO are also analyzed to check for longitudinal variations of column density and relative abundance. Our models show that, based on their predicted relative abundance with respect to SO2 in volcanic plumes, both the tentative KCl detection and SiO upper limit are compatible with a purely volcanic origin for these species.

Moullet, A.; Lellouch, E.; Moreno, R.; Gurwell, M.; Black, J. H.; Butler, B.

2013-10-01

211

Bulk and surface absorptions in the 9.2-10.8-micron region in NaCl and KCl  

NASA Astrophysics Data System (ADS)

The technique of tunable CO2 laser calorimetry was used to study the wavelength dependence of optical absorption in the range 9.2 to 10.8 microns in NaCl and KCl. Samples grown with reactive atmosphere processing (RAP) and those cut from large diameter ingots prepared commercially for fabrication of high-power CO2 laser windows were studied. Total absorption coefficient data at 9.27 and 10.61 microns on monocrystalline and polycrystalline commercially available NaCl were given. Measured bulk absorption values in RAP-grown NaCl are lower than commonly used values for the intrinsic absorption limit in the 10.1 to 10.8 micron wavelength region, and these measured values define a new operational multiphonon absorption limit for NaCl. Bulk absorption in RAP-grown KCl is nearly intrinsic at 10.61 microns, but increases to an order of magnitude above intrinsic near 9.2 microns. The residual bulk absorption observed in KCl crystals may be related to impurities of the ClO3 type.

Vora, H.; Ohmer, M. C.; Stoebe, T. G.

1979-07-01

212

Investigation of a LiCl–KCl–UCl3 system using a combination of X-ray diffraction and differential thermal analyses  

NASA Astrophysics Data System (ADS)

Electrorefining is one of the main steps in pyroreprocessing where spent nuclear fuels are recycled. Electrorefining is conducted in a molten salt of a LiCl–KCl eutectic (59:41 mol%) containing actinide chlorides (AnCl3) at 773 K. In order to operate and maintain the electrorefiner, it is necessary to accumulate fundamental data on the LiCl–KCl–AnCl3 salt, such as its melting point. In this study, based on X-ray diffraction and differential thermal analyses, partial phase diagrams of (LiCl–KCl)eut.–UCl3 pseudo-binary and LiCl–KCl–UCl3 systems, in which the UCl3 concentration was up to 20 mol%, were developed.

Nakayoshi, Akira; Kitawaki, Shinichi; Fukushima, Mineo; Murakami, Tuyoshi; Kurata, Masaki

2013-10-01

213

The phase diagrams and Pitzer model representations for the system KCl + MgCl2 + H2O at 50 and 75°C  

NASA Astrophysics Data System (ADS)

The solubilities in the KCl-MgCl2-H2O system were determined at 50 and 75°C and the phase diagrams and the diagram of refractive index vs composition were plotted. Two invariant point, three univariant curves, and three crystallization zones, corresponding to potassium chloride, hexahydrate (MgCl2 · 6H2O) and double salt (KCl · MgCl2 · 6H2O) showed up in the phase diagrams of the ternary system, The mixing parameters ?K, Ca and ?K, Ca, Cl and equilibrium constant K sp were evaluated in KCl-MgCl2-H2O system by least-squares optimization procedure, in which the single-salt Pitzer parameters of KCl and MgCl2 ?(0), ?(1), ?(2), and C ? were directly calculated from the literature. The results obtained were in good agreement with the experimental data.

Yang, Ji-min; Peng, Jing; Duan, Yu-xia; Tian, Chong; Ping, Mei

2012-12-01

214

Physical chemistry of molten salt batteries. Final report for period October 1, 1979September 30, 1980. Current-induced composition gradients in molten LiCl-KCl  

Microsoft Academic Search

Current induced composition gradients were demonstrated in the molten LiCl-KCl eutectic mixture, the electrolyte of an LiAl\\/LiCl-KCl\\/FeS\\/sub x\\/ battery. The gradients were produced by electrolysis of the salt between LiAl electrodes at currents of 50 to 100 mA cm⁻², and quenching. Analysis of composition profiles in quenched samples was by atomic absorption spectroscopy, which gave good precision, and by x-ray

J. Braunstein; S. Cantor; C. E. Vallet

1981-01-01

215

Vacuum distillation of a mixture of LiCl–KCl eutectic salts and RE oxidative precipitates and a dechlorination and oxidation of RE oxychlorides  

Microsoft Academic Search

In this study, a vacuum distillation of a mixture of LiCl–KCl eutectic salt and rare-earth oxidative precipitates was performed to separate a pure LiCl–KCl eutectic salt from the mixture. Also, a dechlorination and oxidation of the rare-earth oxychlorides was carried out to stabilize a final waste form. The mixture was distilled under a range of 710–759.5Torr of a reduced pressure

Hee Chul Eun; Hee Chul Yang; Yung Zun Cho; Han Soo Lee; In Tae Kim

2008-01-01

216

Evaluation of 2.25Cr1Mo Alloy for Containment of LiCl\\/KCl Eutectic during the Pyrometallurgical Processing of Used Nuclear Fuel  

Microsoft Academic Search

Recovery of uranium from the Mk-IV and Mk-V electrorefiner vessels containing a LiCl\\/KCl eutectic salt has been on-going for 14 and 12 years, respectively, during the pyrometallurgical processing of used nuclear fuel. Although austenitic stainless steels are typically utilized for LiCl\\/KCl salt systems, the presence of cadmium in the Mk-IV electrorefiner dictates an alternate material. A 2.25Cr-1Mo alloy (ASME SA-387)

B. R. Westphal; S. X. Li; G. L. Fredrickson; D. Vaden; T. A. Johnson; J. C. Wass

2011-01-01

217

UV–vis absorption spectroscopic study for on-line monitoring of uranium concentration in LiCl–KCl eutectic salt  

Microsoft Academic Search

UV–vis absorption spectroscopy of uranium in LiCl–KCl eutectic salt at 773K was studied for the on-site use in pyrochemical process. Uranium(III) chloride was electrochemically prepared from uranium metal in LiCl–KCl eutectic salt at 773K by using chronopotentiometry. Three absorption peak positions were selected and calibrated for the quantitative analysis of uranium in the molten salt medium. The molar absorptivity and

Y. J. Park; S. E. Bae; Y. H. Cho; J. Y. Kim; K. Song

2011-01-01

218

Electrochemical Study on the Electrodeposition of U, Nd, Ce, La and Y on a Liquid Cadmium Cathode in a LiCl-KCl Eutectic Salt  

Microsoft Academic Search

Electro-depositions of U, Nd, Ce, La and Y on a liquid cadmium cathode in a LiCl-KCl eutectic salt were studied by using an electrolytic cell. For the LiCl-KCl-UCl- NdCl-CeCl-LaCl-YCl\\/Cd system, cyclic voltammograms and polarization curves were measured and the electrochemical properties of the system were discussed. From the results of the electro-depositions of U and rare earth metals on the

Sung Bin Park; Jong Hyeon Lee; Sung Chan Hwang; Young Ho Kang; Joon Bo Shim; Han Soo Lee; Eung Ho Kim; Seong Won Park

2007-01-01

219

Clustering of Neuronal K+-Cl? Cotransporters in Lipid Rafts by Tyrosine Phosphorylation*  

PubMed Central

The neuronal K+-Cl? cotransporter (KCC2) is a membrane transport protein that extrudes Cl? from neurons and helps maintain low intracellular [Cl?] and hyperpolarizing GABAergic synaptic potentials. Depolarizing ?-aminobutyric acid (GABA) responses in neonatal neurons and following various forms of neuronal injury are associated with reduced levels of KCC2 expression. Despite the importance for plasticity of inhibitory transmission, less is known about cellular mechanisms involved in more dynamic changes in KCC2 function. In this study, we investigated the role of tyrosine phosphorylation in KCC2 localization and function in hippocampal neurons and in cultured GT1-7 cells. Mutation to the putative tyrosine phosphorylation site within the long intracellular carboxyl terminus of KCC2(Y1087D) or application of the tyrosine kinase inhibitor genistein shifted the GABA reversal potential (EGABA) to more depolarized values, indicating reduced KCC2 function. This was associated with a change in the expression pattern of KCC2 from a punctate distribution to a more uniform distribution, suggesting that functional tyrosine-phosphorylated KCC2 forms clusters in restricted membrane domains. Sodium vanadate, a tyrosine phosphatase inhibitor, increased the proportion of KCC2 associated with lipid rafts membrane domains. Loss of tyrosine phosphorylation also reduced oligomerization of KCC2. A loss of the punctuate distribution and oligomerization of KCC2 and a more depolarized EGABA were seen when the 28-amino-acid carboxyl terminus of KCC2 was deleted. These results indicate that direct tyrosine phosphorylation of KCC2 results in membrane clusters and functional transport activity, suggesting a mechanism by which intracellular Cl? concentrations and GABA responses can be rapidly modulated.

Watanabe, Miho; Wake, Hiroaki; Moorhouse, Andrew J.; Nabekura, Junichi

2009-01-01

220

Evidence for KCl Brine Metasomatism in Mafic Xenoliths from the Lower Crust  

NASA Astrophysics Data System (ADS)

The occurrence of Kfs micro-veins in high-grade felsic gneisses has been interpreted as evidence for migrating alkali-rich fluids in the deep crust which may be responsible for melt-absent dehydration of high-grade rocks from amphibolite to granulite facies. Here we present new data on the occurrence of K-feldspar in mafic granulites found as xenoliths in recent alkaline lavas from Western Sardinia, Italy. The xenoliths originated from the underplating of subduction-related basaltic liquids which underwent cooling and recrystallisation in the deep crust (T = 850-900 C, P = 800-1000 MPa). They consist of quartz-free metagabbronorites characterised by Opx + Cpx + Plg porphyroclasts (An50-66) in a granoblastic recrystallized matrix composed of Pyx + Plg (An56-72) + Fe-Ti oxides +/- Kfs +/- Bt +/- FAp +/- Ti-Prg. Texturally, the Kfs occurs in a variety of different modes. These include: (1) rods, blebs, and irregular patches in a random scattering of Plg grains, (2) micro-veins along Plg-Plg and Plg-Pyx grain rims, (3) myrmekite-like intergrowths with Ca-rich Plg along Plg-Plg grain boundaries, and (4) discrete anhedral grains (sometimes microperthitic). The composition of each type of Kfs is characterized by relatively high Ab contents (16-33 mol.%). Increasing An content in the Plg towards the contact with the Kfs micro-vein and myrmekite-like intergrowths into the Kfs along the Plg-Kfs grain boundary are also observed. Small amounts of Bt (TiO2 = 4.7-6.5 wt.%; F = 0.24-1.19 wt.%; Cl = 0.04-0.20 wt.%) in textural equilibrium with the granulite facies assemblage is present in both Kfs-bearing and Kfs-free xenoliths. These Kfs textures, e.g. the randomly scattered and relatively rare antiperthitic plagioclase grains, suggest a likely metasomatic origin due to solid-state infiltration of KCl-rich fluids/melts. The presence of such fluids is supported by the FAp in these xenoliths which is enriched in Cl (Cl = 6-50 % of the total F+Cl+OH). These lines of evidence suggest that formation of Kfs in the mafic xenoliths reflects metasomatic processes, requiring an external K-rich fluid source, which operated in the lower crust during in situ high-T recrystallization of relatively dry rocks.

Montanini, A.; Harlov, D. E.

2004-12-01

221

Purification of used eutectic (LiCl-KCl) salt electrolyte from pyroprocessing  

NASA Astrophysics Data System (ADS)

The separation characteristics of surrogate rare-earth fission products in a eutectic (LiCl-KCl) molten salt were investigated. This system is based on the eutectic salt used for the pyroprocessing treatment of used nuclear fuel (UNF). The investigation was performed using an integrated rare-earth separation apparatus comprising a precipitation reactor, a solid detachment device, and a layer separation device. To separate rare-earth fission products, a phosphate precipitation method using both Li3PO4 and K3PO4 as a precipitant was performed. The use of an equivalent phosphate precipitant composed of 0.408 molar ratio-K3PO4 and 0.592 molar ratio-Li3PO4 can preserve the original eutectic ratio, LiCl-0.592 molar ratio (or 45.2 wt%), as well as provide a high separation efficiency of over 99.5% under conditions of 550 °C and Ar sparging when using La, Nd, Ce, and Pr chlorides. The mixture of La, Nd, Ce, and Pr phosphate had a typical monoclinic (or monazite) structure, which has been proposed as a reliable host matrix for the permanent disposal of a high-level waste form. To maximize the reusability of purified eutectic waste salt after rare-earth separation, the successive rare-earth separation process, which uses both phosphate precipitation and an oxygen sparging method, were introduced and tested with eight rare-earth (Y, La, Ce, Pr, Nd, Sm, Eu and Gd) chlorides. In the successive rare-earth separation process, the phosphate reaction was terminated within 1 h at 550 °C, and a 4-8 h oxygen sparging time were required to obtain over a 99% separation efficiency at 700-750 °C. The mixture of rare-earth precipitates separated by the successive rare-earth separation process was found to be phosphate, oxychloride, and oxide. Through the successive rare-earth separation process, the eutectic ratio of purified salt maintained its original value, and impurity content including the residual precipitant of purified salt can be minimized.

Cho, Yung-Zun; Lee, Tae-Kyo; Eun, Hee-Chul; Choi, Jung-Hoon; Kim, In-Tae; Park, Geun-Il

2013-06-01

222

Further studies on the partial double Donnan. Is isosmotic KCl solution isotonic with cells of respiratory trees of the holothurian Isostichopus badionotus Selenka?  

PubMed

As potassium, chloride and water traverse cell membranes, the cells of stenohaline marine invertebrates should swell if exposed to sea water mixed with an isosmotic KCl solution as they do when exposed to sea water diluted with water. To test this hypothesis respiratory tree fragments of the holothurian Isostichopus badionotus were exposed to five isosmotic media prepared by mixing artificial sodium sea water with isosmotic (611 mmol/l) KCl solution to obtain 100, 83, 71, 60 and 50% sea water, with and without 2 mmol/l ouabain. For comparison, respiratory tree fragments were incubated in sea water diluted to the same concentrations with distilled water, with and without ouabain. Cell water contents and potassium and sodium concentrations were unaffected by KCl-dilution or ouabain in isosmotic KCl-sea water mixtures. In tissues exposed to H(2)O-diluted sea water, cell water increased osmometrically and potassium, sodium and chloride concentrations decreased with dilution; ouabain caused a decrease in potasium and an increase in sodium but no effect on chloride concentrations. The isotonicity of the isosmotic KCl solution cannot be adscribed to impermeability of the cell membrane to KCl as both ions easily traverse the cell membrane. Rather, operationally immobilized extracellular sodium ions, which electrostatically hold back anions and consequently water, together with the lack of a cellward electrochemical gradient for potassium, resulting from membrane depolarization caused by high external potassium concentration, would explain the isotonicity of isosmotic KCl solution. The high external potassium concentration also antagonizes the inhibitory effect of ouabain on the Na(+)/K(+) ATPase responsible for sodium and potassium active transport. PMID:10742500

Herrera; Herrera; López

2000-05-01

223

Influences on the gamma-muscle-spindle system from contralateral muscle afferents stimulated by KCl and lactic acid.  

PubMed

The aim of the present study was to investigate whether increased concentrations of lactic acid and potassium chloride (KCl) in contralateral muscles can influence the sensitivity of primary and secondary muscle spindle afferents (MSAs) from ipsilateral extensor and flexor muscles. The experiments were performed on 7 cats anaesthetised with alpha-chloralose. Recordings were made simultaneously from 2-12 single MSAs from the triceps surae (GS) and/or the posterior biceps and semitendinosus muscles (PBSt). The mean rate of firing and the amplitude of a fitted sine curve of MSA responses to sinusoidal stretching of the receptor bearing muscles were determined. Responses of 42 primary MSAs (17 from PBSt and 25 from GS) were recorded. On 33 of these, clear-cut alterations in sinusoidal response were evoked by injection of 1 ml KCl (200-400 mM) or 1 ml lactic acid (20-50 mM) into the arterial supply of the contralateral GS or PBSt muscles. Six out of 8 secondary MSAs showed sizeable effects to increased intramuscular concentrations of KCl and/or lactic acid (3 from PBSt and 3 from GS). On both primary and secondary MSAs, from GS as well as from PBSt muscles, the large majority of effects were excitatory. All effects on secondary MSAs were compatible with reflex actions on static fusimotor neurones, whereas on primary MSAs different types of reflex responses were observed (i.e. pure static, pure dynamic and mixtures of static and dynamic fusimotor actions). Stimuli related alterations in MSA responses were completely abolished when the contralateral GS or PBSt nerves were anaesthetised.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7777220

Djupsjöbacka, M; Johansson, H; Bergenheim, M; Sjölander, P

1995-02-01

224

Intrinsic shortening speed of temperature-jump-activated intact muscle fibers. Effects of varying osmotic pressure with sucrose and KCl.  

PubMed Central

Effects of intracellular ionic strength on the isotonic contraction properties of both intact fibers and skinned fibers give insights into the cross-bridge mechanism, but presently there is fundamental disagreement in the results on the two fiber preparations. This paper, which studies the effects on contraction of varying the osmotic pressure of the bathing medium with impermeant and permeant solutes, explains the above controversy and establishes the physiological significance of the previous results on skinned fibers. Fast-twitch fibers, isolated singly from tibialis and semitendinosus muscles of frogs, were activated by a temperature-jump technique in hyperosmotic solutions with either 100 or 150 mM sucrose (impermeant), or 50 or 75 mM KCl (permeant). Intracellular ionic strength was expected to rise in these solutions from the standard value of approximately 190 to 265 mM. Cell volume and the speed of unloaded shortening both decreased with sucrose and were constant with KCl. On the other hand, isometric force decreased equally with equiosmolar addition of either solute; this is additional evidence that contractile force decreases with ionic strength and is independent of fiber volume. Therefore, for the main cross-bridges, force per bridge is constant with changes in the lateral separation between the myofilaments. The next finding, that at a fixed cell volume the contraction speed is constant with KCl, provides clear evidence in intact fibers that the intrinsic speed of shortening is insensitive to increased ionic strength. The data with KCl are in agreement with the results on skinned fibers. The results suggest that in the cross-bridge kinetics in vivo the rate-limiting step is different for force than that for shortening. On the other hand, the decrease in speed with sucrose is associated with the shrinkage in cell volume, and is explained by the possibility of an increased internal load. A major fraction of the internal load may arise from unusual interactions between the sliding filaments; these interactions are enhanced in the fibers compressed with sucrose, but this does not affect the intrinsic kinetics of the main cross-bridges. Images FIGURE 2 FIGURE 4 FIGURE 6 FIGURE 7

Gulati, J; Babu, A

1984-01-01

225

Electrochemical and spectroscopic investigations of Tb(III) in molten LiCl–KCl eutectic at high temperature  

Microsoft Academic Search

Electrochemical and spectroscopic properties of Tb(III) in molten LiCl–KCl eutectic at high temperature were investigated by cyclic voltammetry and time-resolved laser-induced fluorescence spectroscopy (TRLFS). The diffusion coefficient of Tb(III) and the formal standard potential of Tb(III)\\/Tb0 were determined to be 2.06±0.4×10?5cm2 s?1 and ?2.83±0.03V vs. Cl2\\/Cl? at 887K, respectively. Additionally, visible fluorescence of Tb(III) due to the electronic transitions from

Bong Young Kim; Dong Hyoung Lee; Jun-Yeop Lee; Jong-Il Yun

2010-01-01

226

Electroconductivity of molten mixtures of LiCl-KCl eutectics with chlorides of rare-earth elements  

NASA Astrophysics Data System (ADS)

The temperature dependences of the specific and molar electroconductivities of LiCl-KCl-LnCl3 (Ln-La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb) molten mixtures were studied. It was shown that the isotherms (1070 K) of molar electroconductivity (?) for most of the studied saline systems have an S-shaped form. The observed patterns of ? isotherms and their dependence on the ratio of components in the saline mixtures under investigation are explained in the context of complex structure of ionic melts.

Kovalevskii, A. V.; Shishalov, V. I.

2011-01-01

227

Dissociation Constants for Citric Acid in NaCl and KCl Solutions and their Mixtures at 25 °C  

Microsoft Academic Search

The constants for the dissociation of citric acid (H3C) have been determined from potentiometric titrations in aqueous NaCl and KCl solutions and their mixtures as a function of ionic strength (0.05–4.5 mol-dm-3) at 25 °C. The stoichiometric dissociation constants (Ki*)\\u000a\\u000a$$\\\\eqalign{\\u000a & {\\\\text{H}}_3 {\\\\text{C}} \\\\rightleftharpoons {\\\\text{H}}^ + + {\\\\text{H}}_2 {\\\\text{C}}^ - ,\\\\quad {\\\\text{K}}_{\\\\text{1}}^{\\\\text{*}} = {{{\\\\text{K}}_1 \\\\gamma ({\\\\text{H}}_3 {\\\\text{C}})} \\\\mathord{\\\\left\\/\\u000a {\\\\vphantom

Francesco Crea; Concetta De Stefano; Frank J. Millero; Virender K. Sharma

2004-01-01

228

Transport of ions across bipolar membranes. 1. Theoretical and experimental examination of the membrane potential of KCl solutions  

SciTech Connect

A calculation method was derived for ionic transport across a bipolar membrane in dialysis systems of mixed salt solutions containing multivalent ions. The calculation of the total membrane potential in the solutions containing KCl alone by this method shows that the potential-salt concentration curve depends both on the direction of the arrangement of the membrane charged layers to the concentration gradient of the salt solutions and on the ratio of the charge densities of the two charged layers. The simulations based on experimentally determined parameters agree with the potential measurements for bipolar membranes produced so that the transport properties depend mainly on their charges. 40 refs., 4 figs., 1 tab.

Higa, Mitsuru; Kira, Akira [Inst. of Physical and Chemical Research (RIKEN), Saitama (Japan)

1995-04-06

229

Plant growth and responses of antioxidants of Chenopodium album to long-term NaCl and KCl stress  

Microsoft Academic Search

The effects of long-term NaCl and KCl treatment on plant growth and antioxidative responses were investigated in Chenopodium album, a salt-resistant species widely distributed in semi-arid and light-saline areas of Xinjiang, China. Growth parameters [plant\\u000a height, branch number, leaf morphology and chlorophyll (Chl) content], the level of oxidative stress [superoxide anion radical\\u000a (O2\\u000a ?), hydrogen peroxide (H2O2) and malondialdehyde (MDA)

Shixiang Yao; Shasha Chen; Dongsheng Xu; Haiyan Lan

2010-01-01

230

Synthesis, Structure, and Properties of Sodium or Potassium-Doped Lanthanum Orthomanganites from NaCl or KCl Flux  

Microsoft Academic Search

Lanthanum and oxygen-deficient La1?x?yAxMnO3??(A=Na or K) ferromagnetic oxide phases have been synthesized from NaCl or KCl flux, starting from La2O3and MnCO3at 900°C. Composition of the final product could be varied by varying initial composition LayMnO3(0.7

Ram Niwas Singh; C. Shivakumara; N. Y. Vasanthacharya; S. Subramanian; M. S. Hegde; H. Rajagopal; A. Sequeira

1998-01-01

231

Ideal Supercapacitor Behavior of Amorphous V 2O 5· nH 2O in Potassium Chloride (KCl) Aqueous Solution  

Microsoft Academic Search

Amorphous a-V2O5·nH2O in mild KCl aqueous electrolyte proves to be an excellent electrode for a faradaic electrochemical capacitor. Cyclic voltammograms versus SCE give ideal capacitor behavior between 0.0 and +0.8 V at pH 6.67 and between ?0.2 and +0.8 V at pH 2.32 with, respectively, a constant specific capacitance over 100 cycles of ca. 350 and 290 F\\/g, respectively. On

Hee Y. Lee; J. B. Goodenough

1999-01-01

232

Studies of some acid–base equilibria in the molten eutectic mixture KCl–LiCl at 700°C  

Microsoft Academic Search

The reversibility of a membrane oxygen electrode Pt(O2)?ZrO2(Y2O3) and acid–base reactions in molten LiCl–KCl at 700°C have been studied by the potentiometric method. The calibration plot has been found to consist of three regions — with predominant effect of oxygen admixtures, with the region at pO>2 and (?E\\/?pO)=2.303RT\\/2F and one region at pO<2 with (?E\\/?pO)=2.303RT\\/F×F. Solubility products of CoO(pP=4.43+0.11), NiO

V. L. Cherginets; T. P. Rebrova

1999-01-01

233

Low temperature CEMS determination of the morphology of rust layers on an iron plate corroded in KCl solution  

NASA Astrophysics Data System (ADS)

CEMS and X-ray diffraction of rust layers on an iron coupon corroded in a 0.02 M KCl solution show that there exists a magnetite layer below an outer lepidocrocite layer. The 10 K spectrum displays three ferric sextets in its lepidocrocite part with fields of 448, 422 and 387 kOe respectively. They are attributed to Fe3+ ions having zero, one and more Cl- ions as first nearest neighbours. The Cl- ions do not seem to be ordered.

Refait, Ph.; Bauer, Ph.; Génin, J.-M. R.

1992-04-01

234

LPE growth of Bi2Sr2CaCu2O(y) from KCl solution  

NASA Astrophysics Data System (ADS)

Superconducting films of Bi2Sr2CaCu2O(y) were epitaxially grown on MgO (001) single crystals using a KCl solvent. Grown layers were characterized by microscope, XRD, and vibrating sample magnetometry. The film was grown on most of the substrate surface, and the surface morphology was fairly smooth. Typical layer thickness was 4 microns. Critical temperature was 85 K from the resistance and the ac susceptibility. Critical current density estimated from magnetization curves was 590 A/sq cm for the ab planet at zero magnetic field and 77 K.

Yasui, Koji; Ido, Toshiyuki; Terada, Hiroshi; Muto, Saburo

1992-12-01

235

Electrochemical behavior of zirconium in molten NaCl-KCl-K 2 ZrF 6 system  

Microsoft Academic Search

The electrochemical reduction of Zr4+ (complex) ions in NaCl-KCl-K2ZrF6 molten salt on Pt electrode was investigated using cyclic voltammetry and square wave voltammetry at 1023 K. Two cathodic\\u000a reduction peaks related to Zr4+\\/Zr2+ and Zr2+\\/Zr steps were observed in the cyclic voltammograms. The result was also confirmed by square wave voltammetry. The diffusion\\u000a coefficient of Zr4+ (complex) ions at 1023

Yanke Wu; Zhigao Xu; Song Chen; Lijun Wang; Guoxun Li

2011-01-01

236

Phase relations in the system NaCl-KCl-H2O: V. Thermodynamic-PTX analysis of solid-liquid equilibria at high temperatures and pressures  

USGS Publications Warehouse

The Gibbs energies of mixing for NaCl-KCl binary solids and liquids and solid-saturated NaCl-KCl-H2O ternary liquids were modeled using asymmetric Margules treatments. The coefficients of the expressions were calibrated using an extensive array of binary solvus and solidus data, and both binary and ternary liquidus data. Over the PTX range considered, the system exhibits complete liquid miscibility among all three components and extensive solid solution along the anhydrous binary. Solid-liquid and solid-solid phase equilibria were calculated by using the resulting equations and invoking the equality of chemical potentials of NaCl and KCl between appropriate phases at equilibrium. The equations reproduce the ternary liquidus and predict activity coefficients for NaCl and KCl components in the aqueous liquid under solid-saturation conditions between 673 and 1200 K from vapor saturation up to 5 kbar. In the NaCl-KCl anhydrous binary system, the equations describe phase equilibria and predict activity coefficients of the salt components for all stable compositions of solid and liquid phases between room temperature and 1200 K and from 1 bar to 5 kbar. ?? 1992.

Sterner, S. M.; Chou, I. -M.; Downs, R. T.; Pitzer, K. S.

1992-01-01

237

A Density Model for Multicomponent Liquids Based on the Modified Quasichemical Model: Application to the NaCl-KCl-MgCl2-CaCl2 System  

NASA Astrophysics Data System (ADS)

A theoretical model based on the modified quasichemical model is presented for the density of multicomponent inorganic liquids such as molten salts. By introducing in the Gibbs energy of the liquid phase temperature-dependent molar volume expressions for the pure components and pressure-dependent excess parameters for the binary (and, if necessary, higher-order) interactions, it is possible to reproduce and eventually predict the molar volume and the density of the multicomponent liquid phase using standard interpolation methods. The model is applied to the NaCl-KCl-MgCl2-CaCl2 liquid solutions. No ternary pressure-dependent model parameters were required; the binary pressure-dependent parameters suffice to reproduce satisfactorily the experimental density data available for the NaCl-KCl-MgCl2, NaCl-KCl-CaCl2, NaCl-MgCl2-CaCl2, KCl-MgCl2-CaCl2, and NaCl-KCl-MgCl2-CaCl2 liquids. This is the first of two articles on the density model. In a subsequent article, the model is applied to the NaF-AlF3-CaF2-Al2O3 base electrolyte used for the electroreduction of alumina in Hall-Héroult cells.

Robelin, Christian; Chartrand, Patrice; Eriksson, Gunnar

2007-12-01

238

Overcoming CML acquired resistance by specific inhibition of Aurora A kinase in the KCL-22 cell model  

PubMed Central

Serine/threonine kinase Aurora A is essential for regulating mammalian cell division and is overexpressed in many types of human cancer. However, the role of Aurora A in chemoresistance of chronic myelogenous leukemia (CML) is not well understood. Using the KCL-22 cell culture model we have recently developed for studying mechanisms of CML acquired resistance, we found that Aurora A expression was partially reduced in these cells upon treatment with the tyrosine kinase inhibitor imatinib, which accompanied the acquisition of BCR-ABL mutation for imatinib resistance. Gene knockdown of BCR-ABL also reduced Aurora A expression, and conversely, Aurora A expression increased in hematopoietic progenitor cells after BCR-ABL expression. Inhibition of Aurora A induced apoptosis of CML cells with or without T315I BCR-ABL mutation and suppressed CML cell growth. Inhibition of Aurora A by gene knockdown or a highly specific small molecule inhibitor sensitized CML cells to imatinib treatment and effectively blocked acquisition of BCR-ABL mutations and KCL-22 cell relapse on imatinib, nilotinib or dasatinib. Our results show that Aurora A plays an important role for facilitating acquisition of BCR-ABL mutation and acquired resistance to tyrosine kinase inhibitors in the culture model and suggest that inhibition of Aurora A may provide an alternative strategy to improve CML treatment to overcome resistance.

Yuan, Hongfeng; Wang, Zhiqiang; Zhang, Hao; Roth, Mendel; Bhatia, Ravi; Chen, Wen Yong

2012-01-01

239

Electrodeposition of Mg-Li-Al-La Alloys on Inert Cathode in Molten LiCl-KCl Eutectic Salt  

NASA Astrophysics Data System (ADS)

Electrochemical preparation of Mg-Li-Al-La alloys on inert electrodes was investigated in LiCl-KCl melt at 853 K (580 °C). Cyclic voltammograms (CVs) and square wave voltammograms (SWVs) show that the existence of AlCl3 or AlF3 could promote La deposition on an active Al substrate, which is predeposited on inert electrodes. All electrochemical tests show that the reduction of La3+ is a one-step reduction process with three electrons exchanged. The reduction of La(III)?La(0) occurred at -2.04 V, and the underpotential deposition (UPD) of La was detected at -1.55 V ( vs Ag/AgCl). The same phenomena concerning La UPD were observed on two inert cathodes, W and Mo. In addition, Mg-Li-Al-La alloys were obtained by galvanostatic electrolysis on the W cathode from La2O3 in LiCl-KCl-MgCl2-KF melts with aluminum as the anode. X-ray diffraction (XRD) measurements indicated that various phases like the Al2La, Al12Mg17, and ?Li phase (LiMg/Li3Mg7) existed in the Mg-Li-Al-La alloys. The distribution of Mg, Al, and La in Mg-Li-Al-La alloys from the analysis of a scan electron micrograph (SEM) and energy dispersive spectrometry (EDS) indicated that the elements Mg, Al, and La distributed homogeneously in the alloys.

Han, Wei; Chen, Qiong; Sun, Yi; Jiang, Tao; Zhang, Milin

2011-12-01

240

In vivo effects of different antispasmodic drugs on the rat bladder contractions induced by topically applied KCl.  

PubMed

The model originally proposed by Postius and Szelenyi for in vivo screening of spasmolytic compounds on the rat urinary bladder, has been modified and tested to verify its predictivity. The topically applied KCl induced reproducible contractions of the bladder that were dose dependently inhibited by i.v. administration of calcium antagonists like nifedipine, nicardipine, and verapamil. The other spasmolytics tested (oxybutynin, terodiline, flavoxate, and papaverine), showed a non-dose-related inhibition of the contractions. The in vivo potency of the calcium antagonists was related to their in vitro activity on the agonist-induced contractions of rat bladder strips, whereas the activity of the other spasmolytics appeared higher than that predicted on the basis of their in vitro efficacy. Nicardipine showed a dose-dependent inhibition of KCl-induced contractions also after oral administration, whereas oxybutynin and papaverine behaved as after i.v. administration. The described model represents, therefore, a good, quantitative, and reproducible tool of screening at the bladder level only for antispasmodic drugs endowed with strong calcium antagonistic activity. PMID:1581612

Angelico, P; Guarneri, L; Fredella, B; Testa, R

1992-03-01

241

Ultra low loss coatings of KCl laser windows. Final report, 1 June 1976--31 December 1977  

SciTech Connect

In the last few years, several low optical absorption 10.6 micrometer AR coatings for KCl have been developed at Hughes Research Laboratories (HRL) and at other laboratories. The objective of this program was the development of 9.27 micrometer AR coatings which have a film absorption loss of less than 0.01% and a reflection of less than 0.1% per surface. The achievement of the program objective will permit the development of a 9.27 micrometer AR coating for a 32.5 cm diameter polycrystalline KCl window. Because previous studies had shown that castings deposited under ultra-high vacuum (UHV) conditions had lower absorption losses than did coatings deposited in conventional vacuum systems, the present study was limited to UHV-deposited films. Mass spectrometer analysis had shown that impurities were evolved occasionally during the evaporation of film materials. As a consequence, residual gas analysis (RGA) was performed to ensure that impurities were not present in the system. Also if impurities were located in the film materials, either they were removed by reactive atmosphere processing (RAP) or techniques were developed to prepare clean material.

Zuccaro, D.

1978-03-01

242

Effect of KCl on melting in the Mg 2 SiO 4 –MgSiO 3 –H 2 O system at 5 GPa  

Microsoft Academic Search

To examine the effect of KCl-bearing fluids on the melting behavior of the Earth’s mantle, we conducted experiments in the\\u000a Mg2SiO4–MgSiO3–H2O and Mg2SiO4–MgSiO3–KCl–H2O systems at 5 GPa. In the Mg2SiO4–MgSiO3–H2O system, the temperature of the fluid-saturated solidus is bracketed between 1,200–1,250°C, and both forsterite and enstatite\\u000a coexist with the liquid under supersolidus conditions. In the Mg2SiO4–MgSiO3–KCl–H2O systems with molar Cl\\/(Cl + H2O) ratios

Linglin Chu; Andreas Enggist; Robert W. Luth

2011-01-01

243

Monosodium glutamate, disodium inosinate, disodium guanylate, lysine and taurine improve the sensory quality of fermented cooked sausages with 50% and 75% replacement of NaCl with KCl.  

PubMed

Fermented cooked sausages were produced by replacing 50% and 75% of NaCl with KCl and adding monosodium glutamate, disodium inosinate, disodium guanylate, lysine and taurine. The manufacturing process was monitored by pH and water activity measurements. The sodium and potassium contents of the resulting products were measured. The color values (L*, a* and b*), texture profiles and sensory profiles were also examined. Replacing 50% and 75% NaCl with KCl depreciated the sensory quality of the products. The reformulated sausages containing monosodium glutamate combined with lysine, taurine, disodium inosinate and disodium guanylate masked the undesirable sensory attributes associated with the replacement of 50% and 75% NaCl with KCl, allowing the production of fermented cooked sausages with good sensory acceptance and approximately 68% sodium reduction. PMID:24008059

Dos Santos, Bibiana Alves; Campagnol, Paulo Cezar Bastianello; Morgano, Marcelo Antônio; Pollonio, Marise Aparecida Rodrigues

2013-08-17

244

A thermodynamic study of electroneutral K-Cl cotransport in pH- and volume-clamped low K sheep erythrocytes with normal and low internal magnesium  

PubMed Central

Swelling-induced human erythrocyte K-Cl cotransport is membrane potential independent and capable of uphill transport. However, a complete thermodynamic analysis of basal and stimulated K-Cl cotransport, at constant cell volume, is missing. This study was performed in low K sheep red blood cells before and after reducing cellular free Mg into the nanomolar range with the divalent cation ionophore A23187 and a chelator, an intervention known to stimulate K- Cl cotransport. The anion exchange inhibitor 4,4'diisothiocyanato- 2,2'disulfonic stilbene was used to clamp intracellular pH and Cl or NO3 concentrations. Cell volume was maintained constant as external and internal pH differed by more than two units. K-Cl cotransport was calculated from the K effluxes and Rb (as K congener) influxes measured in Cl and NO3, at constant internal K and external anions, and variable concentrations of extracellular Rb and internal anions, respectively. The external Rb concentration at which net K-Cl cotransport is zero was defined as flux reversal point which changed with internal pH and hence Cl. Plots of the ratio of external Rb concentrations corresponding to the flux reversal points and the internal K concentration versus the ratio of the internal and external Cl concentrations (i.e., the Donnan ratio of the transported ions) yielded slopes near unity for both control and low internal Mg cells. Thus, basal as well as low internal Mg-stimulated net K-Cl cotransport depends on the electrochemical potential gradient of KCl.

1996-01-01

245

Electronic absorption spectra of nickel dichloride and nickel oxide solutions in the 2CsCl-NaCl and KCl-NaCl metls  

Microsoft Academic Search

The electronic absorption spectra of nickel dichloride and nickel oxide dilute solutions in the 2CsCl-NaCl and KCl-NaCl melts\\u000a have been measured by ultraviolet reflection absorption spectroscopy in the range 250–2500 nm. The spectroscopic data demonstrate\\u000a the formation of stable Ni(II)-based tetrahedral groups (NiCl\\u000a 4\\u000a 2?\\u000a ) in solutions of nickel dichloride in the 2CsCl-NaCl melt, whereas in the KCl-NaCl melt,

A. A. Khokhryakov; M. V. Mikhaleva; A. S. Paivin

2006-01-01

246

Characteristics of 45 Ca uptake stimulated by high KCl of differentiated and undifferentiated NG108-15 and PC12h cells  

Microsoft Academic Search

The characteristics of KCl-stimulated45Ca uptake by neuroblastoma x glioma hybrid NG108-15 cells induced to differentiate with dibutyryl cAMP (Bt2cAMP) and of PC12h pheochromocytoma cells induced to differentiate with nerve growth factor (NGF) were studied. The extent and rate of KCl-stimulated45Ca uptake by differentiated NG108-15 cells induced with Bt2cAMP were significantly higher than those of the undifferentiated cells. However, differentiation of

Seiji Ichida; Naruhisa Matsuda; Satori Nakazaki; Hiroyuki Kishino; Tetsuyuki Wada; Takafumi Akimoto

1993-01-01

247

Time-resolved laser-induced fluorescence spectroscopy of Nd3+ in molten LiCl-KCl eutectic  

NASA Astrophysics Data System (ADS)

The characteristics of the laser-induced fluorescence of Nd3+ in LiCl-KCl eutectic in the wavelength region of 360-900 nm were investigated for information concerning the chemical speciation of Nd-chloride complexes. When pumped at either 355 or 532 nm, Nd3+ in molten salt emits visible and near-IR fluorescence. The fluorescence peaks at 750 nm (4F7/2 + 4S3/2 ? 4I9/2) and 810 nm (4F5/2 + 2H9/2 ? 4I9/2) were particularly prominent at temperatures above the melting point. The fluorescence decay of these transition lines showed a bi-exponential behaviour of the fluorescence lifetime. These results provide evidence that two different chemical species of Nd3+ coexist in this system.

Jung, E. C.; Bae, S.-E.; Park, Y. J.; Song, K.

2011-11-01

248

Adsorption of eutectic LiCl-KCl into zeolite 4A using a mechanically fluidized vacuum system  

SciTech Connect

A high-temperature mixer has been used to absorb LiCl-KCl eutectic salt powders into zeolite 4A. In situ sampling has been performed, allowing for a time-resolved view of the adsorption reaction. The weight percent free (nonabsorbed) chloride ions has been used as a measure of the effectiveness of the adsorption process. Using zeolite 4A powder with no binder, the free chloride concentration leveled off at 0.4--0.5 wt % in less than 5 h at 500 C. Zeolite 4A granules ({minus}60 + 200 mesh) containing binder yielded a free chloride concentration of 0.02 wt % after 5 h at 500 C. It is concluded that the improved performance from the granulated zeolite can be attributed to better mixing within the retort. A 50% reduction in the free chloride concentration below the melting point of the salt suggests that solid-state adsorption of the salt into the zeolite is possible.

Simpson, M.F.; Battisti, T.J. [Argonne National Lab., Idaho Falls, ID (United States)

1999-06-01

249

Voluntary Consumption of NaCl, KCl, CaCl 2 , and NH 4 Cl Solutions by 28 Mouse Strains  

Microsoft Academic Search

Male mice from 28 inbred strains (129P3\\/J, A\\/J, AKR\\/J, BALB\\/cByJ, BUB\\/BnJ, C3H\\/HeJ, C57BL\\/6J, C57L\\/J, CAST\\/Ei, CBA\\/J, CE\\/J, DBA\\/2J, FVB\\/NJ, I\\/LnJ, KK\\/H1J, LP\\/J, NOD\\/LtJ, NZB\\/B1NJ, P\\/J, PL\\/J, RBF\\/DnJ, RF\\/J, RIIIS\\/J, SEA\\/GnJ, SJL\\/J, SM\\/J, SPRET\\/Ei, and SWR\\/J) were tested with NaCl (75–450 mM), KCl (30–300 mM), CaCl2 (3–100 mM), and NH4Cl (10–300 mM) solutions using two-bottle preference tests with water as the

Alexander A. Bachmanov; Gary K. Beauchamp; Michael G. Tordoff

2002-01-01

250

Electrochemistry and Spectroelectrochemistry of Europium(III) Chloride in 3LiCl-2KCl from 643 to 1123 K.  

PubMed

The electrochemical and spectroelectrochemical behavior of europium(III) chloride in a molten salt eutectic, 3LiCl-2KCl, over a temperature range of 643-1123 K using differential pulse voltammetry, cyclic voltammetry, potential step chronoabsorptometry, and thin-layer spectroelectrochemistry is reported. The electrochemical reaction was determined to be the one-electron reduction of Eu(3+) to Eu(2+) at all temperatures. The redox potential of Eu(3+/2+) shifts to more positive potentials, and the diffusion coefficient for Eu(3+) increases as temperature increases. The results for the number of electrons transferred, redox potential, and diffusion coefficient are in good agreement between the electrochemical and spectroelectrochemical techniques. This research extends our ability to develop a spectroelectrochemical sensor for lanthanides and actinides into molten salt media. PMID:24016214

Schroll, Cynthia A; Chatterjee, Sayandev; Levitskaia, Tatiana G; Heineman, William R; Bryan, Samuel A

2013-09-30

251

Determination of uranium and rare-earth metals separation coefficients in LiCl KCl melt by electrochemical transient techniques  

NASA Astrophysics Data System (ADS)

The main step in the pyrometallurgical process of spent nuclear fuel recycling is a molten salt electrorefining. The knowledge of separation coefficients of actinides (U, Np, Pu and Am) and rare-earth metals (Y, La, Ce, Nd and Gd) is very important for this step. Usually the separation coefficients are evaluated from the formal standard potentials of metals in melts containing their own ions, values obtained by potentiometric method. Electrochemical experiments were carried out at 723 823 K in order to estimate separation coefficients in LiCl KCl eutectic melt containing uranium and lanthanum trichlorides. It was shown that for the calculation of uranium and lanthanum separation coefficients it is necessary to determine the voltammetric peak potentials of U(III) and La(III), their concentration in the melt and the kinetic parameters relating to U(III) discharge such as transfer and diffusion coefficients, and standard rate constants of charge transfer.

Kuznetsov, S. A.; Hayashi, H.; Minato, K.; Gaune-Escard, M.

2005-09-01

252

pp and ?? intensity interferometry in collisions of Ar+KCl at 1.76A GeV  

NASA Astrophysics Data System (ADS)

Results on pp, ?+?+, and ?-?- intensity interferometry are reported for collisions of Ar+KCl at 1.76 A GeV beam energy, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. The experimental correlation functions as a function of the relative momentum are compared to model calculations allowing the determination of the space-time extent of the corresponding emission sources. The ?? source radii are found significantly larger than the pp emission radius. The present radii do well complement the beam-energy dependences of Gaussian source radii of the collision system of size A + A ? 40 + 40 . The pp source radius at fixed beam energy is found to increase linearly with the cube root of the number of participants. From this trend, a lower limit of the pp correlation radius is deduced.

Agakishiev, G.; Balanda, A.; Bannier, B.; Bassini, R.; Belver, D.; Belyaev, A. V.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; D?az, J.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Epple, E.; Fabbietti, L.; Fateev, O. V.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Golubeva, M.; González-D?az, D.; Guber, F.; Gumberidze, M.; Heilmann, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Huck, P.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kotte, R.; Krizek, F.; Krücken, R.; Kühn, W.; Kugler, A.; Kurepin, A.; Lang, S.; Lange, J. S.; Lapidus, K.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Morinière, E.; Mousa, J.; Müntz, C.; Naumann, L.; Otwinowski, J.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pérez Cavalcanti, T.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Wagner, V.; Weber, M.; Wendisch, C.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y. V.; Zhou, P.; Zumbruch, P.

2011-05-01

253

Stress corrosion cracking of Ag-20Au in HCLO4, AgCLO4, and KCL solutions by surface mobility  

NASA Astrophysics Data System (ADS)

Slow, intermediate, and ultrafast strain-rate experiments were performed on Ag-20Au (atomic percent) wire samples in 1 M HC1O4, AgClO4, and KCl solutions. Intergranular stress corrosion cracking was found in all of the solutions tested. In the ultrafast strain-rate experiments, 9.6 s-1, in HC1O4 and in AgClO4 solutions, the size of the cracks proved to be a function of the electric charge circulated before straining. AgClO4 was also found to specifically induce stress corrosion cracking (SCC) in the Ag-20Au alloy. The surface mobility SCC mechanism was concluded to be the only one that accounted for all of the experimental observations made in the present work.

Duffó, Gustavo S.; Galvele, José R.

1993-02-01

254

Electronic and Ionic Interactions Analyzed throughConcentration and Charge Fluctuations in KxKCL(1-x) Mixtures  

NASA Astrophysics Data System (ADS)

A deeper insight into short, medium and long ranges behaviour of partial structure factors (PSF) measured in the rich metal domain of KxKCL(1-x) solutions as a function of composition shows up that structural changes are characterised by a non-linear perturbation of the screening properties prevailing in the pure metal liquid. Pseudopotential theory for describing the anion-conduction electron interaction, and perturbation calculations must be dropped. The correlation between long wavelength limits of PSF and thermodynamic is particularly difficult to unravel at k=0. The structural changes observed in neutron diffraction indicate that a better understanding of these correlations consists in treating the correlation between charge fluctuations and atomic concentration fluctuations.

Hily, L.; Dupuy-Philon, J.; Jal, J. F.; Chieux, P.

255

Phosphoregulation of the Na-K-2Cl and K-Cl cotransporters by the WNK kinases  

PubMed Central

Precise regulation of the intracellular concentration of chloride [Cl-]i is necessary for proper cell volume regulation, transepithelial transport, and GABA neurotransmission. The Na-K-2Cl (NKCCs) and K-Cl (KCCs) cotransporters, related SLC12A transporters mediating cellular chloride influx and efflux, respectively, are key determinants of [Cl-]i in numerous cell types, including red blood cells, epithelial cells, and neurons. A common "chloride/volume-sensitive kinase", or related system of kinases, has long been hypothesized to mediate the reciprocal but coordinated phosphoregulation of the NKCCs and the KCCs, but the identity of these kinase(s) has remained unknown. Recent evidence suggests the WNK (with no lysine = K) serine-threonine kinases directly or indirectly via the downstream Ste20-type kinases SPAK/OSR1, are critical components of this signaling pathway. Hypertonic stress (cell shrinkage), and possibly decreased [Cl-]i, triggers the phosphorylation and activation of specific WNKs, promoting NKCC activation and KCC inhibition via net transporter phosphorylation. Silencing WNK kinase activity can promote NKCC inhibition and KCC activation via net transporter dephosphorylation, revealing a dynamic ability of the WNKs to modulate [Cl-]. This pathway is essential for the defense of cell volume during osmotic perturbation, coordination of epithelial transport, and the gating of sensory information in the peripheral system. Commiserate with their importance in serving these critical roles in humans, mutations in WNKs underlie two different Mendelian diseases, pseudohypoaldosteronism type II (an inherited form of salt-sensitive hypertension), and hereditary sensory and autonomic neuropathy type 2. WNKs also regulate ion transport in lower multicellular organisms, including Caenorhabditis elegans, suggesting their functions are evolutionarily-conserved. An increased understanding of how the WNKs regulate the Na-K-2Cl and K-Cl cotransporters may provide novel opportunities for the selective modulation of these transporters, with ramifications for common human diseases like hypertension, sickle cell disease, neuropathic pain, and epilepsy.

Kahle, Kristopher T.; Rinehart, Jesse; Lifton, Richard P.

2012-01-01

256

DC electrical conductivity measurements on KCl and KNO3-added MgSO4·7H2O single crystals  

NASA Astrophysics Data System (ADS)

Pure and impurity-added (with KCl and KNO3) MgSO4·7H2O single crystals were grown by the free-evaporation method and characterized by density and DC electrical conductivity measurements. The present study indicates that the conductivity increases with temperature but does not vary systematically with impurity concentration. Activation energies were also estimated.

Mahadevan, C. K.

2008-01-01

257

Experimental investigation on moving chemical reaction boundary theory for weak-acid–strong-base system with background electrolyte KCl in large concentration  

Microsoft Academic Search

In this report, the moving chemical reaction boundary (MCRB) was formed with the weak acid of acetic acid (HAc) and the strong alkali of NaOH, coupled with the excess of background electrolyte KCl. The experiments were compared with the predictions by the moving chemical reaction boundary equation (MCRBE). It is very interesting that (1) the experimental results are in good

Cheng-Xi Cao; Shu-Lin Zhou; Yi-Tai Qian; You-Zhao He; Li Yang; Qi-Shu Qu; Wen-Kui Chen

2001-01-01

258

Stability of CO 2 clathrate hydrate + CO 2 liquid + CO 2 vapour + aqueous KCl-NaCl solutions: Experimental determination and application to salinity estimates of fluid inclusions  

Microsoft Academic Search

The dissociation temperature of CO 2 clathrate hydrate ( Tm cla ) in the presence of CO 2 liquid + CO 2 vapour + aqueous KCl-NaCl solutions has been determined by microthermometry of fluid inclusions synthesized in quartz. The reliability of the experimental method as a means to examine clathrate equilibria in this four-phase (Q 2 ) assemblage has been

Larryn W. Diamond

1992-01-01

259

Effect of partial NaCl substitution with KCl on the texture profile, microstructure, and sensory properties of low-moisture mozzarella cheese.  

PubMed

The effect of partial substitution of NaCl with KCl on texture profile, soluble Ca, K, Na, and P, and microstructure of low-moisture mozzarella cheese (LMMC) was investigated. LMMC batches were prepared using four combinations of NaCl and KCl salt viz., NaCl only, NaCl:KCl, 3:1, 1:1 and 1:3 (w/w); all used at of 46 g/kg curd and plasticised in 4% brine containing the above salt mixtures. Texture profile, microstructure, and percentages of soluble Ca, K, Na, and P were determined. There were no significant differences in hardness, cohesiveness, adhesiveness, and gumminess among the experimental LMMC batches. Environmental scanning electron microscopy images showed compact and homogeneous structure of LMMC at day 27 of storage; however, no significant difference was observed among the experimental LMMC batches. Hardness increased significantly in all experimental LMMC during storage. LMMC salted with NaCl/KCl mixtures had almost similar sensory properties compared with the control. There was no significant difference in creaminess, bitterness, saltiness, sour-acid, and vinegary taste among the experimental LMMC at the same storage period. PMID:22998741

Ayyash, Mutamed M; Sherkat, Frank; Shah, Nagendra P

2012-09-24

260

Okadaic acid inhibition of KCl cotransport. Evidence that protein dephosphorylation is necessary for activation of transport by either cell swelling or N-ethylmaleimide  

PubMed Central

The mechanism of activation of KCl cotransport has been examined in rabbit red blood cells. Previous work has provided evidence that a net dephosphorylation is required for activation of transport by cell swelling. In the present study okadaic acid, an inhibitor of protein phosphatases, was used to test this idea in more detail. We find that okadaic acid strongly inhibits swelling-stimulated KCl cotransport. The IC50 for okadaic acid is approximately 40 nM, consistent with the involvement of type 1 protein phosphatase in transport activation. N- Ethylmaleimide (NEM) is well known to activate KCl cotransport in cells of normal volume. Okadaic acid, added before NEM, inhibits the activation of transport by NEM, indicating that a dephosphorylation is necessary for the NEM effect. Okadaic acid added after NEM inhibits transport only very slightly. After a brief exposure to NEM and rapid removal of unreacted NEM, KCl cotransport activates with a time delay that is similar to that for swelling activation. Okadaic acid causes a slight increase in the delay time. These findings are all consistent with the idea that NEM activates transport not by a direct action on the transport protein but by altering a phosphorylation- dephosphorylation cycle. The simplest hypothesis that is consistent with the data is that both cell swelling and NEM cause inhibition of a protein kinase. Kinase inhibition causes net dephosphorylation of some key substrate (not necessarily the transport protein); dephosphorylation of this substrate, probably by type 1 protein phosphatase, causes transport activation.

1991-01-01

261

Chemical mechanical planarization of amorphous Ge2Sb2Te5 using KClO4 as oxidizer in acidic slurry  

NASA Astrophysics Data System (ADS)

Amorphous Ge2Sb2Te5 (a-GST) chemical mechanical planarization (CMP) using KClO4 as the oxidizer in an acidicslurry is investigated in the present work. It is shown that the removal rate (RR ) of the a-GST firstly increases and thentends to saturate when the KClO4 concentration is greater than 0.8 wt%, but the static etch rate (SER) linearly increasesfrom low to high KClO4 concentration. To understand the oxidation-reaction capability of Ge, Sb and Te, depth profilesof composition of elements and etch morphology of a-GST immersed in the slurry for some time are measured,respectively. It is found that selective corrosion occurs among Ge, Sb and Te, and an accumulation of Te and loss of Gein a-GST surface region are obvious observed, especially at high KClO4 concentrations. Temperature dependent sheetresistance measurements of all the samples pre- and post-CMP reveal a similar trend, which implies a-GST CMP is ableto keep its characteristic well.

He, Aodong; Song, Zhitang; Bo, Liu; Zhong, Min; Weili, Liu; Wang, Liangyong; Yan, Weixia; Lei, Yu; Wu, Guangping

262

The neuronal K-Cl cotransporter KCC2 influences postsynaptic AMPA receptor content and lateral diffusion in dendritic spines  

PubMed Central

The K-Cl cotransporter KCC2 plays an essential role in neuronal chloride homeostasis, and thereby influences the efficacy and polarity of GABA signaling. Although KCC2 is expressed throughout the somatodendritic membrane, it is remarkably enriched in dendritic spines, which host most glutamatergic synapses in cortical neurons. KCC2 has been shown to influence spine morphogenesis and functional maturation in developing neurons, but its function in mature dendritic spines remains unknown. Here, we report that suppressing KCC2 expression decreases the efficacy of excitatory synapses in mature hippocampal neurons. This effect correlates with a reduced postsynaptic aggregation of GluR1-containing AMPA receptors and is mimicked by a dominant negative mutant of KCC2 interaction with cytoskeleton but not by pharmacological suppression of KCC2 function. Single-particle tracking experiments reveal that suppressing KCC2 increases lateral diffusion of the mobile fraction of AMPA receptor subunit GluR1 in spines but not in adjacent dendritic shafts. Increased diffusion was also observed for transmembrane but not membrane-anchored recombinant neuronal cell adhesion molecules. We suggest that KCC2, likely through interactions with the actin cytoskeleton, hinders transmembrane protein diffusion, and thereby contributes to their confinement within dendritic spines.

Gauvain, Gregory; Chamma, Ingrid; Chevy, Quentin; Cabezas, Carolina; Irinopoulou, Theano; Bodrug, Natalia; Carnaud, Michele; Levi, Sabine; Poncer, Jean Christophe

2011-01-01

263

Role of the neuronal K-Cl co-transporter KCC2 in inhibitory and excitatory neurotransmission  

PubMed Central

The K-Cl co-transporter KCC2 plays multiple roles in the physiology of central neurons and alterations of its function and/or expression are associated with several neurological conditions. By regulating intraneuronal chloride homeostasis, KCC2 strongly influences the efficacy and polarity of the chloride-permeable ?-aminobutyric acid (GABA) type A and glycine receptor (GlyR) mediated synaptic transmission. This appears particularly critical for the development of neuronal circuits as well as for the dynamic control of GABA and glycine signaling in mature networks. The activity of the transporter is also associated with transmembrane water fluxes which compensate solute fluxes associated with synaptic activity. Finally, KCC2 interaction with the actin cytoskeleton appears critical both for dendritic spine morphogenesis and the maintenance of glutamatergic synapses. In light of the pivotal role of KCC2 in the maturation and function of central synapses, it is of particular importance to understand the cellular and molecular mechanisms underlying its regulation. These include development and activity-dependent modifications both at the transcriptional and post-translational levels. We emphasize the importance of post-translational mechanisms such as phosphorylation and dephosphorylation, oligomerization, cell surface stability, clustering and membrane diffusion for the rapid and dynamic regulation of KCC2 function.

Chamma, Ingrid; Chevy, Quentin; Poncer, Jean Christophe; Levi, Sabine

2012-01-01

264

{Lambda}-p femtoscopy in collisions of Ar+KCl at 1.76A GeV  

SciTech Connect

Results on {Lambda}p femtoscopy are reported at the lowest energy so far. At a beam energy of 1.76A GeV, the reaction Ar+KCl was studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. A high-statistics and high-purity {Lambda} sample was collected, allowing for the investigation of {Lambda}p correlations at low relative momenta. The experimental correlation function is compared to corresponding model calculations allowing the determination of the space-time extent of the {Lambda}p emission source. The {Lambda}p source radius is found to be slightly smaller than the pp correlation radius for a similar collision system. The present {Lambda}p radius is significantly smaller than that found for Au+Au/Pb+Pb collisions in the AGS, SPS, and RHIC energy domains but larger than that observed for electroproduction from He. Taking into account all available data, we find the {Lambda}p source radius to increase almost linearly with the number of participants to the power of one-third.

Agakishiev, G.; Destefanis, M.; Gilardi, C.; Kirschner, D.; Kuehn, W.; Lange, J. S.; Metag, V.; Mishra, D.; Pechenova, O.; Spataro, S.; Spruck, B. [II.Physikalisches Institut, Justus Liebig Universitaet Giessen, D-35392 Giessen (Germany); Balanda, A.; Dybczak, A.; Michalska, B.; Otwinowski, J.; Przygoda, W.; Salabura, P.; Trebacz, R.; Wisniowski, M.; Wojcik, T. [Smoluchowski Institute of Physics, Jagiellonian University of Cracow, PL-30-059 Krakow (Poland)

2010-08-15

265

Electrochemical behaviors of PuN and (U, Pu)N in LiCl KCl eutectic melts  

NASA Astrophysics Data System (ADS)

Electrochemical behaviors of PuN and (U, Pu)N in the LiCl KCl eutectic melts at 773 K were investigated by cyclic voltammetry. The electrochemical dissolution of PuN and (U, Pu)N began nearly at -0.90±0.05 and -0.95±0.05 V (vs. Ag+/Ag), respectively. The rest potentials of PuN and (U, Pu)N were observed at about 0.15 V more negative potential than that of UN, in the present experimental condition. The observed rest potentials of (U, Pu)N depended on the equilibrium potential of the Pu3+/PuN. In the cyclic voltammogram measured by use of (U, Pu)N as the working electrode, a steep rise of the positive current was observed at potentials more positive than -0.45 V in analogy with the cyclic voltammogram measured by use of UN as the working electrode. These indicate that UN and PuN in (U, Pu)N would be dissolved independently irrespective of forming the solid solution.

Shirai, O.; Kato, T.; Iwai, T.; Arai, Y.; Yamashita, T.

2005-02-01

266

Electrochemical Study on the Electrodeposition of U, Nd, Ce, La and Y on a Liquid Cadmium Cathode in a LiCl-KCl Eutectic Salt  

SciTech Connect

Electro-depositions of U, Nd, Ce, La and Y on a liquid cadmium cathode in a LiCl-KCl eutectic salt were studied by using an electrolytic cell. For the LiCl-KCl-UCl{sub 3}- NdCl{sub 3}-CeCl{sub 3}-LaCl{sub 3}-YCl{sub 3}/Cd system, cyclic voltammograms and polarization curves were measured and the electrochemical properties of the system were discussed. From the results of the electro-depositions of U and rare earth metals on the LCC, separation factors and recovery ratios of U and REs were obtained and co-electro-depositions of U and REs were investigated. (authors)

Sung Bin Park; Jong Hyeon Lee; Sung Chan Hwang; Young Ho Kang; Joon Bo Shim; Han Soo Lee; Eung Ho Kim; Seong Won Park [Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

2007-07-01

267

Effect of a smooth muscle relaxant from the stonefish, Synanceia trachynis, on KCl-induced responses in the guinea-pig vas deferens.  

PubMed

Stonefish skin secretion contains a smooth muscle relaxant, synancein II, that selectively inhibits tonic responses of KCl-induced contractions of the guinea-pig vas deferens. Synancein II (5-50 micrograms/ml) and nifedipine (10(-8)-10(-7) M) reduced tonic responses equally. Over these concentrations, synancein II inhibited phasic responses more than did nifedipine. Rapid inhibition of phasic responses by synancein II (low concentrations) but its inability to block this response at high concentrations suggests that more than one extracellular and/or intracellular Ca2+ source may contribute to the generation of the phasic response. Some calcium antagonists selectively inhibit tonic responses induced by KCl in many different organs, whilst others inhibit phasic responses. Whereas we previously reported that synancein II selectively inhibits phasic rather than tonic responses in the guinea-pig ileum, the present results reveals a reversal of this selectivity. PMID:3770070

Hoy, A W; Cameron, A M

1986-09-23

268

Consequence of condensed-phase formation in transient burning of TiH\\/sub x\\/\\/KClOâ in a closed system  

Microsoft Academic Search

Transient burning of TiH\\/sub X\\/\\/KClOâ in a closed system is formulated including the effect of condensed species. Thermodynamic properties are evaluated using both BLAKE and TIGER computer codes. Three different equations of state for gaseous species are used and their effect on the burning rate is evaluated. For more accurate transient burning analysis, a pressure dependent covolume for gaseous species

A. Razani; M. Shahinpoor; S. L. Hingorani-Norenberg

1989-01-01

269

Determination of effective conductivity of porous ceramic separators of LiAl\\/LiCl-KCl\\/FeS cells. [BN felt and MgO powder  

Microsoft Academic Search

High-temperature (450°C) lithium-aluminum\\/iron sulfide cells containing LiCl-KCl electrolyte are currently under development at Argonne National Laboratory (ANL). In this type of cell, electrodes are usually made by pressing mixtures of active material powder and electrolyte on a current collecting substrate, thus forming porous electrode structure. Both the negative and positive electrodes are isolated by a porous separator composed of a

H. Ohno; H. Shimotake

1980-01-01

270

Physico-chemical investigations on the electronic partial conductivity of molten electrolytes, especially of the eutectic mixture LiCl-KCl  

NASA Astrophysics Data System (ADS)

The self-discharge of lithium-sulfur batteries caused by the electronic partial conductivity of the electrolyte was estimated. Stationary polarization measurements were used to determine the electronic conductivity in the eutectic melt LiCl-KCl at temperatures from 400 to 500 C. From investigations on the solubility of lithium in the melt, the diffusion coefficient of the conducting particles was obtained using a coulometric titration method.

Rickert, H.; Meyer, M.

1984-09-01

271

LIQUEFACTION OF BEYPAZARI LIGNITE USING NiCl2-KCl-LiCl CATALYSTS. 1. DIFFERENCE IN SOLID AND MOLTEN SALT CATALYSIS  

Microsoft Academic Search

Liquefaction of Beypazan lignite in tetralin using NiCl2-KCl-LiCl (14:36:50 molar percentages) as catalyst was investigated. Effects of the catalyst\\/lignite ratio and temperature were determined in experiments done at 275°C, 300°C and 360°C. Liquid products were separated into oils, asphaltenes and asphaltols by a solvent extraction method. Yield of liquefaction increased with temperature in all experiments, the highest yield was observed

Y. Yürüm; J. Özkisacik; S. Bekta?

1990-01-01

272

Low temperature molten salt synthesis of SrTiO 3 submicron crystallites and nanocrystals in the eutectic NaCl–KCl  

Microsoft Academic Search

An eutectic NaCl–KCl molten salts method has been developed for the synthesis of SrTiO3 submicron crystallites and nanocrystals from SrO2 and two kinds (submicron and nano-sized) of TiO2 powders at 700°C, which was much lower than that (generally>1000°C) of the conventional solid state reactions. The characterization results from X-ray diffraction and X-ray photoelectron spectroscopy revealed that the obtained products were

Hui-Ling Li; Zhen-Ni Du; Gen-Lin Wang; Yong-Cai Zhang

2010-01-01

273

Distillation and condensation of LiCl–KCl eutectic salts for a separation of pure salts from salt wastes from an electrorefining process  

Microsoft Academic Search

Salt separation and recovery from the salt wastes generated from a pyrochemical process is necessary to minimize the high-level waste volumes and to stabilize a final waste form. In this study, the thermal behavior of the LiCl–KCl eutectic salts containing rare earth oxychlorides or oxides was investigated during a vacuum distillation and condensation process. LiCl was more easily vaporized than

Hee Chul Eun; Hee Chul Yang; Han Soo Lee; In Tae Kim

2009-01-01

274

Synthetic fluid inclusions. V. Solubility relations in the system NaCl-KCl-H sub 2 O under vapor-saturated conditions  

Microsoft Academic Search

Vapor-saturated solubility relationships in the system NaCl-KCl-HâO have been determined by experimentally synthesizing fluid inclusions in quartz in the presence of known brine compositions and then measuring the dissolution temperatures of halite and\\/or sylvite daughter crystals within the inclusions using a microscope equipped with a heating stage. These data, along with other literature values have been used in a stepwise

S. M. Sterner; D. L. Hall; R. J. Bodnar

1988-01-01

275

Synthetic fluid inclusions. V. Solubility relations in the system NaCl-KCl-H 2 O under vapor-saturated conditions  

Microsoft Academic Search

Vapor-saturated solubility relationships in the system NaCl-KCl-H 2 O have been determined by experimentally synthesizing fluid inclusions in quartz in the presence of known brine compositions and then measuring the dissolution temperatures of halite and\\/or sylvite daughter crystals within the inclusions using a microscope equipped with a heating stage. These data, along with other literature values have been used in

S. Michael Sterner; Donald L. Hall; Robert J. Bodnar

1988-01-01

276

Evaluation of the Electrochemical Behavior of CeCl3 in Molten LiCl-KCl Eutectic Utilizing Metallic Ce as an Anode  

Microsoft Academic Search

A study of the electrochemical behavior of CeCl3 in LiCl-KCl eutectic was performed in the temperature range 653-973K to ascertain if CeCl3 is a suitable surrogate for UCl3 in the development of nuclear fuel cycle technologies. Reduction of cerium occurs in a single 3-electron step that is quasi-reversible. The diffusion coefficient of Ce(III) was determined by linear sweep voltammetry and

K. C. Marsden; B. Pesic

2011-01-01

277

Study on the preparation of Mg–Li–Zn alloys by electrochemical codeposition from LiCl–KCl–MgCl 2–ZnCl 2 melts  

Microsoft Academic Search

Electrochemical codeposition of Mg, Li, and Zn on a molybdenum electrode in LiCl–KCl–MgCl2–ZnCl2 melts at 943K to form Mg–Li–Zn alloys was investigated. Cyclic voltammograms (CVs) showed that the potential of Li metal deposition, after the addition of MgCl2 and ZnCl2, is more positive than the one of Li metal deposition before the addition. Chronopotentiometry measurements indicated that the codeposition of

Yong De Yan; Mi Lin Zhang; Yun Xue; Wei Han; Dian Xue Cao; Shu Quan Wei

2009-01-01

278

Preparing different phases of Mg-Li-Sm alloys by molten salt electrolysis in LiCl-KCl-MgCl 2-SmCl 3 melts  

Microsoft Academic Search

Different phases of Mg-Li-Sm alloys were prepared by galvanostatic electrolysis in LiCl-KCl-MgCl2-SmCl3 melts at 670 °C. The electrolysis process and phase control of Mg-Li-Sm alloys were studied. The microstructures of ?, ?+?, ? phases of Mg-Li-Sm alloys were characterized by X-ray diffraction (XRD) and optical microscope (OM). Analysis of scanning electron microscopy (SEM) and EDS mapping analysis showed that Mg

Wei HAN; Yang TIAN; Milin ZHANG; Ke YE; Quanyou ZHAO; Shuquan WEI

2010-01-01

279

Thermochemical properties of lanthanides (Ln = La, Nd) and actinides (An = U, Np, Pu, Am) in the molten LiCl KCl eutectic  

NASA Astrophysics Data System (ADS)

The electrochemical reduction of actinides (U, Pu, Np and Am) and lanthanides (La and Nd) chlorides was investigated by cyclic voltammetry and chronopotentiometry at different temperatures in LiCl KCl eutectic. The diffusion coefficients of these metallic cations were estimated as well as their apparent standard potentials. These values of potentials are compared with existing data measured also by transient electrochemical techniques or e.m.f. measurements.

Masset, Patrick; Konings, Rudy J. M.; Malmbeck, Rikard; Serp, Jérôme; Glatz, Jean-Paul

2005-09-01

280

Thermodynamics of brine-salt equilibria -- II. The system NaCl-KCl-H 2 O from 0 to 200°C  

Microsoft Academic Search

Thermodynamic functions describing salt solubilities and activities in the system NaCl-KCl-H 2 O have been obtained over the temperature range 0-200°C using existing isopiestic and solubility data. The two-parameter equation used previously at 25°C was sufficient to characterize the activity coefficient of the aqueous binary systems from infinite dilution to saturation, and the mixing behavior could be described by Harned's

James R. Wood

1976-01-01

281

Phonon dispersion in K0.5Rb0.5Cl and KCl0.5Br0.5 mixed crystals  

Microsoft Academic Search

Phonon dispersion relations in K0.5Rb0.5Cl and KCl0.5Br0.5 have been measured by coherent inelastic neutron scattering at 300 K. Some of the acoustic phonons and most of the optical phonons are split and show two peaks of nearly equal weight around the mean position. Both the observed maxima show a similar dispersion against the wave vector. The observed phonon frequencies are

M. M. Beg; M. Kobbelt

1982-01-01

282

Oxidative Activation of K-Cl Cotransport by Diamide in Erythrocytes from Humans with Red Cell Disorders, and from Several Other Mammalian Species  

Microsoft Academic Search

.   Red blood cells (RBCs) from different mammalian species were investigated for the presence of diamide-induced oxidative activation\\u000a of K-Cl cotransport reported to be present in sheep but absent in human RBCs. K efflux was measured in RBCs from human with\\u000a hemoglobin (Hb) A or S, glucose-phosphate dehydrogenase (G6PDH) and a cytoskeletal deficiency, and from rat, mouse and rabbit.\\u000a RBCs

N. C. Adragna; P. K. Lauf

1997-01-01

283

Electron-spin-resonance study of Tl atom defects in KCl and relativistic many-body analysis of the hyperfine structure  

Microsoft Academic Search

Two thallium atom defects of tetragonal symmetry around are produced by x irradiation above 230 K in KCl: TlCl. Their electron-spin-resonance spectra are characterized by comparable and large g shifts but quite different hyperfine parameters. A relativistic many-body calculation of the Tl0 atom hyperfine interaction including the effect of a tetragonal crystal field permits a quantitative analysis of the spin-Hamiltonian

E. Goovaerts; J. Andriessen; S. V. Nistor; D. Schoemaker

1981-01-01

284

Sensory characterisation and consumer acceptability of small calibre fermented sausages with 50% substitution of NaCl by mixtures of KCl and potassium lactate.  

PubMed

The effect of six mixtures with 50% molar substitution of KCl (0-50%) and potassium lactate (0-50%) as NaCl substitutes in small calibre fermented sausages on some sensory parameters and on the acceptability was studied. Also, the relationship between sensory profile and consumer acceptability using external preference mapping was investigated. The results showed that as the K-lactate substitution increased, pH, sweetness, crumbliness and pastiness also increased, and piquantness, hardness, cohesiveness, ripened flavour, acid taste and saltiness decreased. However, the treatments prepared with a high level of salt substitution by KCl showed scores of sensory attributes similar to those of the control. Consumer segmentation showed differences in acceptability between genders, place of residence, educational level and age group. Consumers rejected fermented sausages with high K-lactate substitution but not those with a high KCl substitution. External preference mapping split consumers up into four clusters with different preference patterns. According to these results and from a sensory point of view, it is possible to achieve a reduction of 50% of NaCl in small calibre fermented sausages and to obtain a product acceptable to most consumers. PMID:22063862

Guàrdia, M D; Guerrero, L; Gelabert, J; Gou, P; Arnau, J

2008-06-03

285

Vacuum distillation of a mixture of LiCl-KCl eutectic salts and RE oxidative precipitates and a dechlorination and oxidation of RE oxychlorides.  

PubMed

In this study, a vacuum distillation of a mixture of LiCl-KCl eutectic salt and rare-earth oxidative precipitates was performed to separate a pure LiCl-KCl eutectic salt from the mixture. Also, a dechlorination and oxidation of the rare-earth oxychlorides was carried out to stabilize a final waste form. The mixture was distilled under a range of 710-759.5Torr of a reduced pressure at a fixed heating rate of 4 degrees C/min and the LiCl-KCl eutectic salt was completely separated from the mixture. The required time for the salt distillation and the starting temperature for the salt vaporization were lowered with a reduction in the pressure. Dechlorination and oxidation of the rare-earth oxychlorides was completed at a temperature below 1300 degrees C and this was dependent on the partial pressure of O2. The rare-earth oxychlorides (NdOCl/PrOCl) were transformed to oxides (Nd2O3/PrO2) during the dechlorination and oxidation process. These results will be utilized to design a concept for a process for recycling the waste salt from an electrorefining process. PMID:18440139

Eun, Hee Chul; Yang, Hee Chul; Cho, Yung Zun; Lee, Han Soo; Kim, In Tae

2008-03-22

286

Oriented silver chloride microcrystals and nanocrystals embedded in a crystalline KCl matrix, as studied by means of electron paramagnetic resonance and optically detected magnetic resonance  

NASA Astrophysics Data System (ADS)

Self-trapped holes (STH), self-trapped excitons (STE) and shallow electron centres in small AgCl crystals embedded in a KCl crystalline matrix have been observed by means of optically detected magnetic resonance (ODMR). The existence of the impurity clusters in heavily doped KCl:AgCl single crystals, ranging from single and paired Ag ions to AgCl nanometre- and micrometre-size crystals (nanocrystals and microcrystals) retaining the orientation of the matrix, was confirmed. ODMR spectra were used as a fingerprint of the embedded AgCl microcrystals and a signature of their crystallinity. For AgCl nanocrystals the anisotropy of the g-factor both for isolated STH and for STH forming STE was found to be substantially reduced compared with those of bulk AgCl crystals and AgCl microcrystals embedded in KCl. This implies a considerable suppression of the Jahn-Teller effect in nanoparticles. A rather general mechanism of the suppression of the Jahn-Teller effect in nanocrystals is developed, taking into account the additional deformation field appearing because of the strong vibronic interaction at the interface. It allows evaluation of the critical size of the embedded AgCl nanocrystals, at which the suppression of the Jahn-Teller effect has its onset; the value obtained is ?10 nm, in agreement with experiment.

Baranov, P. G.; Romanov, N. G.; Khramtsov, V. A.; Vikhnin, V. S.

2001-03-01

287

Vapor pressure of ZrCl{sub 4} and HfCl{sub 4} over melt systems KCl + AlCl{sub 3} (1:1.04 mol) + ZrCl{sub 4} and KCl + AlCl{sub 3} (1:1.04 mol) + HfCl{sub 4}  

SciTech Connect

The vapor pressures of ZrCl{sub 4} and HfCl{sub 4} over a molten salt mixture of KCl + AlCl{sub 3} (1:1.04 mol) + XCl{sub 4} (X = Zr, Hf) was determined in the temperature range of 485--627 K by the transpiration technique. The compositions of ZrCl{sub 4} and HfCl{sub 4} in the molten salt system were chosen such that it would be useful for vapor phase separation of ZrCl{sub 4} from Zr(Hf)Cl{sub 4} by an extractive distillation technique employing KCl + AlCl{sub 3} as the fused salt solvent. The relative volatility factor of p{sub HfCl{sub 4}}/p{sub ZrCl{sub 4}} over the KCl + AlCl{sub 3} + XCl{sub 4} (X = Zr, Hf) molten salt systems was determined to be 1.5 in the composition range of 16--30 mol % HfCl{sub 4} or ZrCl{sub 4}. This indicated the possibility of separation of ZrCl{sub 4} and HfCl{sub 4} by extractive distillation with KCl + AlCl{sub 3} molten salt solvent at ambient pressure. Zirconium, with some minor alloy addition, is primarily used in nuclear power reactors as core structural materials due to its low thermal neutron cross section, excellent high-temperature strength, and resistance to corrosion in water.

Tangri, R.P.; Bose, D.K.; Gupta, C.K. [Bhabha Atomic Research Centre, Bombay (India). Materials Group

1995-07-01

288

Thermodynamics of mixing of liquids in the system Ca 3 (PO 4 ) 2 CaCl 2 CaF 2 Ca(OH) 2  

Microsoft Academic Search

Molten calcium halide and hydroxide salts may be used as flux and reactants in determining apatite exchange equilibria and solid solution behavior. New experimental data and published phase equilibria are used to determine a thermodynamic model of melts and solids along the binary joins of the anhydrous apatite system Ca 3 (PO 4 ) 2 ---CaCl 2 ---CaF 2 ---Ca(OH)

R. C. Tacker; J. C. Stormer Jr.

1993-01-01

289

Thermal analysis of binary mixtures of CaO, CaO 2 , Ca(OH) 2 , and Mg(OH) 2 with sodium and potassium perchlorates  

Microsoft Academic Search

The catalytic activity of magnesium oxide, calcium oxide, and calcium peroxide in reactions of dioxygen evolution from sodium and potassium perchlorates has been studied. Additives of CaO facilitate the complete decomposition of perchlorates within the same temperature range as that found for additives of Mn, Co, Ni, and Cu oxides. Tile data oil the low catalytic activity of calcium oxide

V. V. Klyucharev; M. Sinel'nikov; A. P. Razumova; V. D. Sasnovskaya

1996-01-01

290

CO 2 reaction with Ca(OH) 2 during SO 2 removal with convective pass sorbent injection and high temperature filtration  

Microsoft Academic Search

The Kyoto Protocol calls for greenhouse gas emission reductions which could affect the use of coal for producing electricity. Carbon credits are being explored as a method for countries to meet their reduction commitments. Carbon dioxide removal in flue gas desulfurization (FGD) systems should be considered if and when the concept of carbon credits are implemented. This paper addresses the

Guang G. Li; Tim C. Keener; Antoinette W. Stein; Soon J. Khang

2000-01-01

291

Physical chemistry of molten-salt batteries. Final report, October 1, 1981September 30, 1982. LiCl precipitation from LiCl-KCl anolyte in porous Li-Al electrodes  

Microsoft Academic Search

Composition gradients such as those predicted to occur during discharge of porous Li-Al negative electrodes of Li\\/S batteries with LiCl-KCl eutectic electrolyte were generated and measured in the LiCl-KCl anolyte of an electrolysis cell with Li-Al electrodes. LiCl precipitation during electrolysis was observed by two-dimensional scanning of electrolyte composition in the front part of quenched porous Li-Al anode sections using

C. E. Vallet; D. E. Heatherly; L. Jr. Heatherly; J. Braunstein

1983-01-01

292

Enhanced expression of the neuronal K+/Cl- cotransporter, KCC2, in spontaneously depressed Flinders Sensitive Line rats.  

PubMed

We used Flinder Sensitive Line (FSL) rats, a genetic model of unipolar depression, to examine whether changes in central GABAergic transmission are associated with a depressed phenotype. FSL rats showed an increased behavioral response to low doses of diazepam, as compared to either Sprague Dawley (SD) or Flinder Resistant Line (FRL) rats used as controls. Diazepam at a dose of 0.3 mg/kg, i.p., induced a robust impairment of motor coordination in FSL rats, but was virtually inactive in SD or FRL rats. The increased responsiveness of FSL rats was not due to changes in the brain levels of diazepam or its active metabolites, or to increases in the number or affinity of benzodiazepine recognition sites, as shown by the analysis of [(3)H]-flunitrazepam binding in the hippocampus, cerebral cortex or cerebellum. We therefore examined whether FSL rats differed from control rats for the expression levels of the K(+)/Cl(-) cotransporter, KCC2, which transports Cl(-) ions out of neurons, thus creating the concentration gradient that allows Cl(-) influx through the anion channel associated with GABA(A) receptors. Combined immunoblot and immunohistochemical data showed a widespread increase in KCC2 expression in FSL rats, as compared with control rats. The increase was more prominent in the cerebellum, where KCC2 was largely expressed in the granular layer. These data raise the interesting possibility that a spontaneous depressive state in animals is associated with an amplified GABAergic transmission in the CNS resulting from an enhanced expression of KCC2. PMID:20153734

Matrisciano, F; Nasca, C; Molinaro, G; Riozzi, B; Scaccianoce, S; Raggi, M A; Mercolini, L; Biagioni, F; Mathè, A A; Sanna, E; Maciocco, E; Pignatelli, M; Biggio, G; Nicoletti, F

2010-02-11

293

Activity-Dependent Regulation of the K/Cl Transporter KCC2 Membrane Diffusion, Clustering, and Function in Hippocampal Neurons.  

PubMed

The neuronal K/Cl transporter KCC2 exports chloride ions and thereby influences the efficacy and polarity of GABA signaling in the brain. KCC2 is also critical for dendritic spine morphogenesis and the maintenance of glutamatergic transmission in cortical neurons. Because KCC2 plays a pivotal role in the function of central synapses, it is of particular importance to understand the cellular and molecular mechanisms underlying its regulation. Here, we studied the impact of membrane diffusion and clustering on KCC2 function. KCC2 forms clusters in the vicinity of both excitatory and inhibitory synapses. Using quantum-dot-based single-particle tracking on rat primary hippocampal neurons, we show that KCC2 is slowed down and confined at excitatory and inhibitory synapses compared with extrasynaptic regions. However, KCC2 escapes inhibitory synapses faster than excitatory synapses, reflecting stronger molecular constraints at the latter. Interfering with KCC2-actin interactions or inhibiting F-actin polymerization releases diffusion constraints on KCC2 at excitatory but not inhibitory synapses. Thus, F-actin constrains KCC2 diffusion at excitatory synapses, whereas KCC2 is confined at inhibitory synapses by a distinct mechanism. Finally, increased neuronal activity rapidly increases the diffusion coefficient and decreases the dwell time of KCC2 at excitatory synapses. This effect involves NMDAR activation, Ca(2+) influx, KCC2 S940 dephosphorylation and calpain protease cleavage of KCC2 and is accompanied by reduced KCC2 clustering and ion transport function. Thus, activity-dependent regulation of KCC2 lateral diffusion and clustering allows for a rapid regulation of chloride homeostasis in neurons. PMID:24068817

Chamma, Ingrid; Heubl, Martin; Chevy, Quentin; Renner, Marianne; Moutkine, Imane; Eugène, Emmanuel; Poncer, Jean Christophe; Lévi, Sabine

2013-09-25

294

Electrochemical formation of Dy alloy films in a molten LiCl-KCl-DyCl3 system  

NASA Astrophysics Data System (ADS)

As to the electrochemical formation of Dy-Ni alloy films in a molten LiCl-KCl-DyCl3 system at 700 K, the growth of DyNi2 film and behavior of anodic dissolution of Dy from the formed DyNi2 film were investigated. The DyNi2 films were formed by potentiostatic electrolysis at 0.55, 0.62 and 0.70 V with Ni electrodes. The growth rates of DyNi2 films are higher at less noble potential, i.e., 0.47 8m min-1 at 0.55 V, 0.32 8m min-1 at 0.62 V and 0.14 8m min-1 at 0.70 V. From RBS analysis, it was suggested that the Dy-Ni alloy film was formed for 10 or 30 s during electrodepositing Dy at 0.30 V with a Ni electrode. Moreover, the growth rate of Dy-Ni alloy film was faster than that of Dy-Fe alloy film. Anodic electrolysis of the formed DyNi2 film with thickness of 15 ?m was conducted at 0.90 V, 1.30 V and 1.90 V, respectively. The formed DyNi2 were transformed to other phases, i.e., DyNi3, DyNi5 and Ni, by selective anodic dissolution of Dy. The transformed Ni film was about 10 ?m in thickness and had a porous structure with a pore diameter of 1~2 ?m.

Konishi, H.; Usui, T.; Nohira, T.; Ito, Y.

2009-05-01

295

Thermal-gradient migration of brine inclusions in salt crystals. [Synthetic single crystals of NaCl and KCl  

SciTech Connect

It has been proposed that high-level nuclear waste be disposed in a geologic repository. Natural-salt deposits, which are being considered for this purpose, contain a small volume fraction of water in the form of brine inclusions distributed throughout the salt. Radioactive-decay heating of the nuclear wastes will impose a temperature gradient on the surrounding salt which mobilizes the brine inclusions. Inclusions filled completely with brine migrate up the temperature gradient and eventually accumulate brine near the buried waste forms. The brine may slowly corrode or degrade the waste forms which is undesirable. In this work, thermal gradient migration of both all-liquid and gas-liquid inclusions was experimentally studied in synthetic single crystals of NaCl and KCl using a hot-stage attachment to an optical microscope which was capable of imposing temperature gradients and axial compressive loads on the crystals. The migration velocities of the inclusions were found to be dependent on temperature, temperature gradient, and inclusion shape and size. The velocities were also dictated by the interfacial mass transfer resistance at brine/solid interface. This interfacial resistance depends on the dislocation density in the crystal, which in turn, depends on the axial compressive loading of the crystal. At low axial loads, the dependence between the velocity and temperature gradient is non-linear.At high axial loads, however, the interfacial resistance is reduced and the migration velocity depends linearly on the temperature gradient. All-liquid inclusions filled with mixed brines were also studied. For gas-liquid inclusions, three different gas phases (helium, air and argon) were compared. Migration studies were also conducted on single crystallites of natural salt as well as in polycrystalline natural salt samples. The behavior of the inclusions at large angle grain boundaries was observed. 35 figures, 3 tables.

Yagnik, S.K.

1982-09-01

296

Stability of CO 2 clathrate hydrate + CO 2 liquid + CO 2 vapour + aqueous KCl-NaCl solutions: Experimental determination and application to salinity estimates of fluid inclusions ?  

NASA Astrophysics Data System (ADS)

The dissociation temperature of CO 2 clathrate hydrate ( Tmcla) in the presence of CO 2 liquid + CO 2 vapour + aqueous KCl-NaCl solutions has been determined by microthermometry of fluid inclusions synthesized in quartz. The reliability of the experimental method as a means to examine clathrate equilibria in this four-phase (Q 2) assemblage has been confirmed by reproducing independent results in the literature on the NaCl-CO 2-H 2O system. Regression fitting of the new experimental measurements and interpolation with published NaCl-CO 2-H 2O data allows the stability of CO 2 clathrate in the Q 2 assemblage of the KCl-NaCl-CO 2-H 2O quaternary system to be described as follows: wt% ( KCl + NaCl) = 15.5296 + 4.2947 XKCL + 0.5061 ( XKCL) 2 -1.0709 TmCLA - 0.4751 TmCLA - 0.048( TmCLA) 2 (1) where wt% (KC1 + NaCl) denotes the total salt concentration in the aqueous liquid (with respect to the salt-H 2O subsystem), TmCLA is in °C, and XKCL denotes the relative weight fraction of salts: wt% KCl/ (wt% KCl + wt% NaCl). This equation is valid over the range 0-19 wt% (KC1 + NaCl), and 0-1 XKCL When coupled with fluid inclusion KCl/NaCl ratios analyzed by methods other than microthermometry, Eqn. (1) yields compositions in terms of individual electrolyte concentrations. In natural fluid inclusions, depending on their bulk compositions and densities, clathrate may dissociate as part of the Q 2 assemblage (for which ThCO2> TmCLA), or in either of two three-phase assemblages (for which ThCO2< TmCLA). The new experimental data on the Q 2 assemblage, and those in the literature, may be applied to natural three-phase assemblages as well. This is enabled by the following functions which relate TmCLA, and ThCO2 measured in the metastable absence of clathrate, to equivalent wt% NaCl in the salt-H 2O subsystem of the aqueous liquid. For inclusions in which CO 2 homogenizes via a bubblepoint transition ( ThCO2< TmCLA): eq. wt% NaCl = 15.6151 - 0.03627 x + 0.00164 x2 - 0.9491 y - 0.00287 xy - 0.02464 y2 - 0.00107 xy2 - 0.00222 y3. (2) For inclusions in which CO 2 homogenizes via a dew-point transition ( ThCO2dew < TmCLA): eq. wt% NaCl = 15.5131 + 0.065705 x - 0.00778 x2 - 1.05135 y + 0.02687 xy - 0.04717 y2 + 0.00138 xy2 - 0.00411 y3 (3) where x denotes ThCO2 between -20 and + 10°C, y denotes TmCLA, and eq. NaCl concentration is between 0 and 21 wt%. Equations (2) and (3) thus permit salinities to be estimated for the large class of natural KCl-NaCl-CO 2-H 2O fluid inclusions in which ThCO2is higher than the clathrate nucleation temperature.

Diamond, Larryn W.

1992-01-01

297

Statistical optimization of medium components for the production of biosurfactant by Bacillus licheniformis K51.  

PubMed

The nutritional medium requirement for biosurfactant production by Bacillus licheniformis K51 was optimized. The important medium components, identified by the initial screening method of Plackett-Burman, were H3PO4, CaCl2, H3BO3, and Na-EDTA. Box-Behnken response surface methodology was applied to further optimize biosurfactant production. The optimal concentrations for higher production of biosurfactants were (g/l): glucose, 1.1; NaNO3, 4.4; MgSO4 x 7H2O, 0.8; KCl, 0.4; CaCl2, 0.27; H3PO4, 1.0 ml/l; and trace elements (mg/l): H3BO3, 0.25; CuSO4, 0.6; MnSO4, 2.2; Na2MoO4, 0.5; ZnSO4, 6.0; FeSO4, 8.0; CoCl2, 1.0; and Na-EDTA, 30.0. Using this statistical optimization method, the relative biosurfactant yield as critical micelle dilution (CMD) was increased from 10x to 105x, which is ten times higher than the non-optimized rich medium. PMID:18051763

Joshi, Sanket; Yadav, Sanjay; Nerurkar, Anuradha; Desai, Anjana J

2007-02-01

298

a Modified Denitrifying Bacteria Method for Dual Stable Isotopic Analysis of of Soil Nitrate in Kcl Extracts: Identification of Bioindicators of Nitrogen Deposition Along a Gradient in the Sonoran Desert  

NASA Astrophysics Data System (ADS)

Previous studies performing dual isotopic analysis of nitrate in KCl soil extracts using denitrifying bacteria have not incorporated alterations in the method to compensate for the increased N2O blank produced when the bacteria are exposed to KCl in solution. When 1M KCl is used as a blank, the amount of N2O released from the concentrated bacteria solution is more than four times as high as when using a DI water blank. The excess N2O produced is not an artifact of nitrate impurity in the KCl, although the blank increases with the molarity of KCl up to 1M. The introduction of N2O gas is significant enough to alter the values of IAEA USGS standards (3 ?g in 3ml KCl) which in turn results in an inaccurate regression for unknown samples. We reduced the size of the KCl blank and its effect on the standards by adding 3ml of KCl to the bacteria solution prior to purging the sample with He gas. This removes the N2O gas which is released by the bacteria when they initially come in contact with the KCl, and allows for standards to be calibrated to a precision of ± 0.1 % ?15N and ± 0.2 % ?18O. Using this new method, we measured ?15N and ?18O of nitrate in 1M KCl soil extracts taken from surface soil (5cm cores) along a nitrogen deposition gradient spanning the Coachella Valley in the western Sonoran Desert during the summer. Early germinating winter annual plant species (Schismus barbatus, Chaenactic fremontii, and Malacothrix glabrata) were collected as seedlings early in the growing season and again in late spring before senescence. Leaves from the dominant shrub, Larrea tridentata, were also collected from each site. Soil nitrogen from sites on the eastern edge of the valley had ?18O values between +30 and +41%, indicating an influence of atmospheric nitrate in plant available nitrate. There was an inverse correlation (r2=0.907) between soil ?18O and the ?15N of the C.fremontii leaf tissue, which suggests that in areas of high N deposition, some seedlings are able to take up excess nitrogen deposited to the soil surface in the summer. Leaf tissue from L. tridentata had a similar relationship with calculated summer atmospheric nitrogen deposition. These results indicate anthropogenic nitrate is only evident in the soils in areas of high deposition and that isotopic composition of the leaf tissue of some widespread species may be able to be used as a bioindicator of deposition.

Bell, M. D.; Sickman, J. O.; Allen, E. B.

2011-12-01

299

Ion-pair Formation and Ion Mobilities in Aqueous NaCl and KCl at High Temperatures from Conductance Data  

NASA Astrophysics Data System (ADS)

The electrical conductivity of aqueous solutions of NaCl have been measured at 651 K and 670 K at 28 MPa for molalities up to 1.0 mol/kg. These conductivities plus the results of Hwang et al.(1970), Ritzert and Franck (1968), and Mangold and Franck (1969) for aqueous KCl have been fit to the conductance equation of Turq, et al. (1995) with a consensus mixing rule and either mean spherical approximation or Debye - Hückel activity coefficients. Except at one state point, where the Coulomb interactions are the strongest ( ? *}= (e2)/(4??0 ? k T a) = 17.8, where ? and a are the dielectric constant of water and the closest distance of ions approach, respectively), the simplest model that fits the experimental results reasonably well (± 2-3 %) at molalities up to 4.5 moles/kg is one with only the limiting equivalent conductance and a pair association constant adjusted. Activity coefficients calculated with either the MSA and ionic diameters or with the Debye - Hückel equation of Oelkers and Helgeson (with no salting out) can be used with similar accuracy. At high concentrations this model predicts strong redisociation of the ion pairs which form at low concentrations. The cluster model of Laria, et al.(1990) for the restricted primitive model is consistent with the qualitative predictions of our preferred model of pair association only. The model of Oelkers and Helgeson (1993) with substantial multi-ion association (triplets and quartets) does not fit the data without the physically unrealistic salting out coefficient so this model is not recommended. For the state point with the highest betastarr (NaCl at 670 K and 28 MPa), more complex models are needed at concentrations above 0.05 mol/kg. Good fits to the data were found for multi-ion association models (5 adjustable parameters) and reasonable fits were found with only pair association and more complex activity models (4 adjustable parameters) so that the models are about equally accurate at equal complexities for this solution.

Balashov, V. N.; Balashov, V. N.; Wood, R. H.; Sharygin, A. V.; Zimmerman, G. H.

2001-12-01

300

Phorbol ester attenuates the KCl-induced increase in (Ca/sup 2 +/) and inhibits spontaneous sarcoplasmic reticulum Ca/sup 2 +/ release, in rat cardiac myocytes  

SciTech Connect

Partial membrane depolarization induced by increasing the KCl concentration of the medium bathing cardiac myocytes leads to an increase in cell (Ca/sup 2 +/), and accelerates the frequency of spontaneous contractile waves (W) caused by periodic sarcoplasmic reticulum (SR) Ca/sup 2 +/ release. In suspensions of myocytes bathed in 1.0mM Ca/sup 2 +/ at 37 (pH 7.4) and loaded with the fluorescent Ca/sup 2 +/ - indicator Fura-2, by incubation with 2 ..mu..M acetoxymethyl ester for 30 min, the addition of KCl to raise (K/sup +/) from 5 to 30 mM is associated with a rapid (< 10 sec) increase in fluorescence, corresponding to an increased cell (Ca/sup 2 +/). Prior exposure (3 min) to 10/sup -7/ M phorbol myristate acetate (PMA) diminishes this response to 44 +/- 10% of that in control suspensions (n = 9). Under the same conditions W frequency (min/sup -1/) in individual cells in 30 mM KCl averaged 8.3 +/- 0.6. Addition of PMA abolished W within 1 min. Diacylglycerol (10 ..mu..M L..cap alpha..-1,2-dioctanoylglycerol, di C8) had a similar effect on W frequency. The thesis is that PMA attenuates cell Ca/sup 2 +/ overload and its associated potentiation of spontaneous SR Ca/sup 2 +/ oscillations. In view of the efficacy of PMA and di C8, it is suggested that the effect is mediated by protein kinase c, and it may involve an alteration in the intracellular distribution of this enzyme.

Hansford, R.G.; Capogrossi, M.C.; Kaku, T.; Pelto, D.J.; Filburn, C.H.; Lakatta, E.G.

1986-03-01

301

Extraction of europium and electrodeposition of Al–Li–Eu alloy from Eu 2O 3 assisted by AlCl 3 in LiCl–KCl melt  

Microsoft Academic Search

The work presents an electrochemical study on preparation of Al–Li–Eu alloys on a tungsten electrode in molten LiCl–KCl–AlCl3–Eu2O3 system at 753K and 953K. Gibbs energy shows that AlCl3 can chloridize Eu2O3, with a discharge in the form of Eu(??I) ions on the cathode. The electrochemical behavior of Al(???), Li(?) and Eu(??I) and alloy formation processes were investigated by cyclic voltammetry,

Yong De Yan; Hao Tang; Mi Lin Zhang; Yun Xue; Wei Han; Dian Xue Cao; Zhi Jian Zhang

302

The properties of the surface of molten mixtures of the LiCl-KCl eutectic with praseodymium, samarium, erbium, and ytterbium chlorides  

NASA Astrophysics Data System (ADS)

The temperature dependence of surface tension was studied and the excess Gibbs energy of the surface of a sphere with a molar volume of molten quasi-binary mixtures of the LiCl-KCl eutectics with LnCl3 (Ln = Pr, Sm, Er, and Yb) was calculated. The influence of rare-earth and alkali metal cations on the surface properties of the systems studied was considered. Deviations from ideal surface tension isotherms and excess Gibbs energy of the surface of a sphere with a molar volume are explained by the complex structure of melts.

Shishalov, V. I.; Kovalevskii, A. V.

2011-01-01

303

Synthesis of plate-like ?-Al 2O 3 single-crystal particles in NaCl–KCl flux using Al(OH) 3 powders as starting materials  

Microsoft Academic Search

Plate-like ?-Al2O3 single-crystal particles were successfully synthesized in NaCl–KCl flux using Al(OH)3 powders as starting materials, and the influence of pre-calcining of Al(OH)3 powders on the phase formation and morphology of ?-Al2O3 powders was focused. When Al(OH)3 powders are used as starting materials, the synthesized product at 900°C is mainly composed of ?-Al2O3 and ?-Al2O3, and most synthesized particles show

Li-Hui Zhu; Qing-Wei Huang; Wei Liu

2008-01-01

304

Cation occupancy at the A1\\/A2 sites in strontium barium niobate micro-crystals grown from molten NaCl and KCl salts  

Microsoft Academic Search

The cation chemistry in two sets of strontium barium niobate (SBN) micro-crystals, synthesized at 1100°C via molten NaCl and KCl salts was investigated using analytical electron microscopy. Na+ and K+ ions were found to enter the tungsten bronze (TB) structure to form the filled TB phase Sr4?mBamNa2Nb10O30 or the partially filled TB phase (Sr,Ba)4+nK2?2n?n Nb10O30. Small Na+ ions fill the

Xian-Hao Wang; Hui Gu; Qing-Wei Huang; Miran ?eh

2007-01-01

305

Characteristics of Oxidation Reaction of Rare-earth Chlorides for Precipitation in LiCl-KCl Molten Salt by Oxygen Sparging  

Microsoft Academic Search

The precipitation reaction of some rare earth chlorides (La\\/Ce\\/Nd\\/GdCl3) in a LiCl-KCl molten salt has been carried out by using the oxygen sparging method. In this study, regardless of the oxygen sparging time and the molten salt temperature, oxychlorides (REOCl) for LaCl3, NdCl3 and GdCl3, and an oxide (REO2) for CeCl3 are formed as a precipitate. The conversion of rare-earth

Yong-Jun CHO; Hee-Chul YANG; Hee-Chul EUN; Eung-Ho KIM; In-Tae KIM

2006-01-01

306

Electrochemical Formation of Mg–Li–Sm Alloys by Codeposition from LiCl–KCl–MgCl 2 –SmCl 3 Molten Salts  

Microsoft Academic Search

In this article, the electrochemical method of preparing Mg–Li–Sm alloys by codeposition in LiCl–KCl–MgCl2–SmCl3 melts was investigated. Transient electrochemical techniques, such as cyclic voltammetry, chronopotentiometry, and chronoamperometry\\u000a were used to explore the electrochemical formation of Mg–Li–Sm alloys. Chronopotentiograms demonstrated that the codepositon\\u000a of Mg, Li, and Sm occurred when current densities were more negative than ?0.31 A cm?2. Chronoamperograms indicated that the

Wei Han; Fengli Wang; Yang Tian; Milin Zhang; Yongde Yan

307

Neutron diffraction study of the Li-Cl distance in molten mixture systems (Li, K)Cl and (Li, Cs)Cl  

Microsoft Academic Search

Neutron diffraction with a time-of-flight method has been performed for the molten binary systems (7Li, K)Cl and (7Li, Cs)Cl at 1073 K and 973 K, respectively, with the main aim of determining the change in the nearest neighbour Li-Cl distance with concentration; the concentrations investigated were xLiCl (mole fraction of LiCl)=0, 0·20, 0·35, 0·50, 0·65 and 0·80 for the former,

Yasushi Miyamoto; Susumu Okazaki; Osamu Odawara; Isao Okada; Masakatsu Misawa; Toshiharu Fukunaga

1994-01-01

308

[Study of the metal precipitation from decontamination leachates of municipal wastes fly ash incinerators].  

PubMed

This research work focuses on the development of a new process for the decontamination of municipal wastes incinerators fly ashes. The objective of this study was to evaluate different total and selective precipitation methods for metals removal from ash decontamination leachates. The tested options include 1) use of hydrated lime and caustic soda for selective (pH 5.0) and total (pH 8.5) metal precipitation; 2) addition of different chemicals (H3PO4, Na2S and FeCl3) in a pH range from 6.0 to 9.0. Fly ash decontamination assays using alkaline and acid washing steps were initially performed using optimal conditions previously established. Treated fly ashes respected the standards based on the TCLP leaching test for all studied metals and SPLP. Total metal precipitation tests carried out at pH 8.5 achieve removal yields for all metals > or = 90% using hydrated lime and > or = 83% using caustic soda. Selective precipitation tests alone at pH 5.0 show removal yields > or = 97% for Cr and between 75 and 87% for Al and Pb. Moreover, assays carried out using a stoechiometric addition of Na2S have allowed the separation of Cd (> or = 99%) and Zn (> or = 71%) as metal sulphides (CdS and ZnS). From an economical point of view, the most interesting option seems to be the leachates neutralization at pH 7.0 using Ca(OH)2 combined with the reuse of the treated leachates in the fly ash leaching steps. Metal precipitation cost at pH 7.0 has been estimated to be 22.7 CAN dollars tct-1 using Ca(OH)2, and 26.7 CAN dollars tct-1 using NaOH. PMID:15906494

Levasseur, B; Blais, J F; Mercier, G

2005-04-01

309

Evaluation of the Electrochemical Behavior of CeCl3 in Molten LiCl-KCl Eutectic Utilizing Metallic Ce as an Anode  

SciTech Connect

A study of the electrochemical behavior of CeCl3 in LiCl-KCl eutectic was performed in the temperature range 653-973K to ascertain if CeCl3 is a suitable surrogate for UCl3 in the development of nuclear fuel cycle technologies. Reduction of cerium occurs in a single 3-electron step that is quasi-reversible. The diffusion coefficient of Ce(III) was determined by linear sweep voltammetry and chronopotentiometry. The standard potential of Ce(III)/Ce(0) was measured and used to calculate Gibbs free energy and the activity coefficient. The nucleation of cerium on a tungsten substrate was determined to be instantaneous with hemispherical nuclei whose growth is controlled by linear or hemispherical diffusion. The order of magnitude of the exchange current density was determined by the linear polarization method. The electrochemical characteristics of CeCl3 were compared with those of UCl3 in LiCl-KCl to evaluate the potential of cerium as a surrogate for uranium electrorefining development.

K. C. Marsden; B. Pesic

2011-04-01

310

Solubilities of salts in the ternary systems NaCl + CaCl2 + H2O and KCl + CaCl2 + H2O at 75°C  

NASA Astrophysics Data System (ADS)

The solubility in the NaCl-CaCl2-H2O and KCl-CaCl2-H2O systems were determined at 75°C and the phase diagrams and the diagram of physicochemical property vs composition were plotted. One invariant point, two univariant curves, and two crystallization zones, corresponding to potassium chloride, dihydrate (CaCl2 · 2H2O) showed up in the phase diagrams of the ternary systems. The mixing parameters ?M, Ca and ?M, Ca, Cl (M = Na or K) and equilibrium constant K sp were evaluated in NaCl-CaCl2-H2O and KCl-CaCl2-H2O systems by least-squares optimization procedure, in which the single-salt Pitzer parameters of NaCl, KCl, and CaCl2 ?(0), ?(1), ?(2), and C ? were directly calculated from the literature. The results obtained were in good agreement with the experimental data.

Yang, Ji-Min; Liu, Xiao-Lin; Liang, Pei-Pei

2011-07-01

311

Comparative study of various pretreatment reagents on rice husk and structural changes assessment of the optimized pretreated rice husk.  

PubMed

The performance of alkalis (NaOH and Ca(OH)2) and acids (H2SO4, HCl, H3PO4, CH3COOH, and HNO3) in the pretreatment of rice husk was screened, and a suitable reagent was assessed for subsequent optimization using response surface methodology. From the assessment, HCl that hydrolysed rice husk well was optimized with three parameters (HCl loading, pretreatment duration, and temperature) using Box-Behnken Design. The optimized condition (0.5% (w/v) HCl loading, 125 °C, 1.5 h) is relatively mild, and resulted in ~22.3mg TRS/ml hydrolysate. The reduced model developed has good predictability, where the predicted and experimental results differ by only 2%. The comprehensive structural characterization studies that involved FT-IR, XRD, SEM, and BET surface area determination showed that the pretreated rice husk consisted mainly of cellulose and lignin. Compared to untreated rice husk, pretreated rice husk possessed increased pore size and pore volume, which are expected to be beneficial for fungal growth during fermentation. PMID:23138072

Ang, Teck Nam; Ngoh, Gek Cheng; Chua, Adeline Seak May

2012-09-24

312

An experimental study of the solubility of molybdenum in H[subscript 2]O and KCl?H2O solutions from 500 [degrees]C to 800 [degrees]C, and 150 to 300 MPa  

SciTech Connect

The solubility of molybdenum (Mo) was determined at temperatures from 500 C to 800 C and 150 to 300 MPa in KCl-H{sub 2}O and pure H{sub 2}O solutions in cold-seal experiments. The solutions were trapped as synthetic fluid inclusions in quartz at experimental conditions, and analyzed by laser ablation inductively coupled plasma mass spectrometry (LA ICPMS). Mo solubilities of 1.6 wt% in the case of KCl-bearing aqueous solutions and up to 0.8 wt% in pure H{sub 2}O were found. Mo solubility is temperature dependent, but not pressure dependent over the investigated range, and correlates positively with salinity (KCl concentration). Molar ratios of {approx}1 for Mo/Cl and Mo/K are derived based on our data. In combination with results of synchrotron X-ray absorption spectroscopy of individual fluid inclusions, it is suggested that Mo-oxo-chloride complexes are present at high salinity (>20 wt% KCl) and ion pairs at moderate to low salinity (<11 wt% KCl) in KCl-H{sub 2}O aqueous solutions. Similarly, in the pure H{sub 2}O experiments molybdic acid is the dominant species in aqueous solution. The results of these hydrothermal Mo experiments fit with earlier studies conducted at lower temperatures and indicate that high Mo concentrations can be transported in aqueous solutions. Therefore, the Mo concentration in aqueous fluids seems not to be the limiting factor for ore formation, whereas precipitation processes and the availability of sulfur appear to be the main controlling factors in the formation of molybdenite (MoS{sub 2}).

Ulrich, Thomas; Mavrogenes, John (Australian National University)

2008-04-22

313

Temperature dependence of the f?f hypersensitive transitions of Ho 3+ and Nd 3+ in molten salt solvents and the structure of the LaCl 3–KCl melts  

Microsoft Academic Search

The electronic absorption spectra of the hypersensitive transitions 5G6?5I8 of Ho3+ and 4G5\\/2?4I9\\/2 of Nd3+ have been measured in molten LiCl–KCl eutectic and in LaCl3–KCl molten mixtures. The ligand field components of the above transitions in octahedral symmetry have been identified and the molar absorptivity changes with temperature and composition have been measured. The spectra are discussed in terms of

A. Chrissanthopoulos; G. N. Papatheodorou

2006-01-01

314

Vapor-liquid phase equilibria of potassium chloride-water mixtures: Equation-of-state representation for KCl-H sub 2 O and NaCl-H sub 2 O  

SciTech Connect

Measurements of isothermal vapor-liquid compositions for KCl-H{sub 2}O as a function of pressure are reported. An equation of state, which was originally proposed by Pitzer and was improved and used by Tanger and Pitzer to fit the vapor-liquid coexistence surface for NaCl-H{sub 2}O, has been used for representation of the KCl-H{sub 2}O system from 300 to 410{degree}C. Improve parameters are also reported for NaCl-H{sub 2}O from 300 to 500{degree}C.

Hovey, J.K.; Pitzer, K.S.; Tanger, J.C. IV (Lawrence Berkeley Lab., CA (USA)); Bischoff, J.L.; Rosenbauer, R.J. (Geological Survey, Menlo Park, CA (USA))

1990-02-08

315

Vapor-liquid phase equilibria of potassium chloride-water mixtures: Equation-of-state representation for KCl-H2O and NaCl-H2O  

USGS Publications Warehouse

Measurements of isothermal vapor-liquid compositions for KCl-H2O as a function of pressure are reported. An equation of state, which was originally proposed by Pitzer and was improved and used by Tanger and Pitzer to fit the vapor-liquid coexistence surface for NaCl-H2O, has been used for representation of the KCl-H2O system from 300 to 410??C. Improved parameters are also reported for NaCl-H2O from 300 to 500??C. ?? 1990 American Chemical Society.

Hovey, J. K.; Pitzer, K. S.; Tanger, IV, J. C.; Bischoff, J. L.; Rosenbauer, R. J.

1990-01-01

316

Novel furostanol saponins from the bulbs of Allium macrostemon B. and their bioactivity on [Ca2+]i increase induced by KCl.  

PubMed

Chemical reinvestigation of the ethanol extract of the dried bulbs of Allium macrostemon B. led to the isolation of two novel furostanol saponins, named macrostemonoside M (1) and macrostemonoside N (2), together with six known saponins. The structures of new compounds were elucidated on the basis of extensive spectroscopic analysis including 1D and 2D NMR as (25R)-22-hydroxy-5beta-furostane-1beta,2beta,3beta,6alpha-tetraol-26-O-beta-D-glucopyranoside and 22-hydroxy-5beta-furost-25-(27)-ene-1beta,2beta,3beta,6alpha-tetraol-26-O-beta-D-glucopyranoside, respectively. The pharmacological activities of all the saponins on [Ca2+]i increase induced by KCl were evaluated. PMID:16753778

Chen, Hai-Feng; Wang, Nai-Li; Sun, Hong-Li; Yang, Bao-Feng; Yao, Xin-Sheng

317

Environmentally friendly growth of single-crystalline K{sub 2}Ti{sub 6}O{sub 13} nanoribbons from KCl flux  

SciTech Connect

Single-crystalline K{sub 2}Ti{sub 6}O{sub 13} nanoribbons with typical width ranging from one hundred nanometers to a few hundred nanometers and length up to tens of microns were prepared from KCl flux. The nanoribbons were characterized by a range of methods including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, selected area electron diffraction and high-resolution transmission electron microscopy. Ultraviolet-visible experiments showed that the K{sub 2}Ti{sub 6}O{sub 13} nanoribbons were wide-band semiconductors with a band width E{sub g} = 3.4 eV. The mechanism of one-dimensional growth of the nanoribbons was attributed to the oriented attachment mechanism.

Xu Lianqiang, E-mail: xuwenqiang998@126.com [Department of Physics and Information Technology, Ningxia Teachers University, Guyuan Ningxia, 756000 (China); Cheng Li [Department of Physics and Information Technology, Ningxia Teachers University, Guyuan Ningxia, 756000 (China)

2010-02-15

318

Seizure sensitivity is ameliorated by targeted expression of K+-Cl- cotransporter function in the mushroom body of the Drosophila brain.  

PubMed

The kcc(DHS1) allele of kazachoc (kcc) was identified as a seizure-enhancer mutation exacerbating the bang-sensitive (BS) paralytic behavioral phenotypes of several seizure-sensitive Drosophila mutants. On their own, young kcc(DHS1) flies also display seizure-like behavior and demonstrate a reduced threshold for seizures induced by electroconvulsive shock. The product of kcc shows substantial homology to KCC2, the mammalian neuronal K(+)-Cl(-) cotransporter. The kcc(DHS1) allele is a hypomorph, and its seizure-like phenotype reflects reduced expression of the kcc gene. We report here that kcc functions as a K(+)-Cl(-) cotransporter when expressed heterologously in Xenopus laevis oocytes: under hypotonic conditions that induce oocyte swelling, oocytes that express Drosophila kcc display robust ion transport activity observed as a Cl(-)-dependent uptake of the K(+) congener (86)Rb(+). Ectopic, spatially restricted expression of a UAS-kcc(+) transgene was used to determine where cotransporter function is required in order to rescue the kcc(DHS1) BS paralytic phenotype. Interestingly, phenotypic rescue is largely accounted for by targeted, circumscribed expression in the mushroom bodies (MBs) and the ellipsoid body (EB) of the central complex. Intriguingly, we observed that MB induction of kcc(+) functioned as a general seizure suppressor in Drosophila. Drosophila MBs have generated considerable interest especially for their role as the neural substrate for olfactory learning and memory; they have not been previously implicated in seizure susceptibility. We show that kcc(DHS1) seizure sensitivity in MB neurons acts via a weakening of chemical synaptic inhibition by GABAergic transmission and suggest that this is due to disruption of intracellular Cl(-) gradients in MB neurons. PMID:19884312

Hekmat-Scafe, Daria S; Mercado, Adriana; Fajilan, Adriel A; Lee, Ann W; Hsu, Richard; Mount, David B; Tanouye, Mark A

2009-11-02

319

Deep sub-threshold K*(892)0 production in collisions of Ar + KCl at 1.76 A GeV  

NASA Astrophysics Data System (ADS)

Results on the deep sub-threshold production of the short-lived hadronic resonance K*(892)0 are reported for collisions of Ar + KCl at 1.76A GeV beam energy, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. The K*(892)0 production probability per central collision of P_{K^{*0}}=(4.4± 1.1 ± 0.5)× 10^{-4} and the K*(892)0/K0 ratio of P_{K^{*0}}/P_{K^0}=(1.9± 0.5± 0.3)× 10^{-2} are determined at the lowest energy so far ( i.e. deep below the threshold for the corresponding production in nucleon-nucleon collisions, sqrt{s_{NN}}-sqrt{s_{thr}}=-340 MeV). The K*0/K0 ratio is compared with results of other experiments and with the predictions of the UrQMD transport approach and of the statistical hadronization model. The experimental K*0 yield and the K*0/K0 ratio are overestimated by the transport model by factors of about five and two, respectively. In a chemically equilibrated medium the ratio corresponds to a temperature of the thermalized system being systematically lower than the value determined by the yields of the stable and long-lived hadrons produced in Ar + KCl collisions. From the present measurement, we conclude that sub-threshold K* production either cannot be considered to proceed in a system being in thermal equilibrium or these short-lived resonances appear undersaturated, for example as a result of the rescattering of the decay particles in the ambient hadronic medium.

Agakishiev, G.; Balanda, A.; Bassini, R.; Belver, D.; Belyaev, A. V.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; Díaz, J.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Epple, E.; Fabbietti, L.; Fateev, O. V.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Golubeva, M.; González-Díaz, D.; Guber, F.; Gumberidze, M.; Heilmann, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Huck, P.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kotte, R.; Krizek, F.; Krücken, R.; Kühn, W.; Kugler, A.; Kurepin, A.; Lang, S.; Lange, J. S.; Lapidus, K.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Morinière, E.; Mousa, J.; Müntz, C.; Naumann, L.; Otwinowski, J.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pérez Cavalcanti, T.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Wagner, V.; Weber, M.; Wendisch, C.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y. V.; Zumbruch, P.

2013-03-01

320

The use of the concept of solvation excesses for studying the mutual distribution of solution component particles in the H2O-KCl-NaCl and H2O-KNO3-NaNO3 systems  

NASA Astrophysics Data System (ADS)

The data on component activities and salt solubilities were analyzed to determine solvation excesses in the H2O-KCl-NaCl and H2O-KNO3-NaNO3 systems. Some rules governing the solvation of ions were discussed.

Pendin, A. A.; Kazak, A. S.

2010-08-01

321

Chalcogenide chemistry in molten salts. I. Selenium(IV) acido-basic and redox properties in the LiCl–KCl eutectic melt at 450, 500, 550 and 600 °C  

Microsoft Academic Search

Molten salt chemistry of chalcogenides has become a major concern in relation to two current great application domains which are (i) nuclear energy (pyrochemical nuclear waste treatment and molten salt reactors) and (ii) electrodeposition of functional material thin films (photovoltaic, magnetism, supraconductivity, etc.). This paper reports experimental data relevant to the molten salt chemistry of selenium in the molten LiCl–KCl

Sylvie Rouquette-Sanchez; Gérard S. Picard

2004-01-01

322

Thermodynamic properties and single-electrode Peltier heats of a Li-Al alloy in a LiCl-KCl eutectic melt  

SciTech Connect

Thermodynamic properties of a Li-Al alloy in the two-phase ({alpha}Al + {beta}LiAl), ({beta}LiAl + {gamma}Li{sub 3}Al{sub 2}), and ({gamma}Li{sub 3}Al{sub 2} + liquid) regions, and in the single {beta}LiAl phase region were determined from electromotive force measurements in a LiCl-KCl eutectic melt at temperatures from 650 to 76f0 K. From the obtained thermodynamic properties, the single-electrode Peltier heat of a Li-Al alloy electrode was evaluated as a function of the alloy composition. It turned out that the single-electrode Peltier heat of a Li-Al alloy electrode exhibits discontinuities at the compositions of coexisting-single phase boundaries. The change of the single-electrode Peltier heat on a phase boundary was interpreted thermodynamically and was found to follow from thermodynamic data for the single phases and the phase diagram data.

Amezawa, Koji; Yamamoto, Naoichi; Tomii, Yoichi; Ito, Yasuhiko [Kyoto Univ. (Japan)

1999-03-01

323

Synchronously pumped mode locked 1.73-2.10-micron tunable laser operation of (F2(+)) sub AH centers in KCl:Na(+):O2 crystals  

NASA Astrophysics Data System (ADS)

Using synchronous pumping with about 100-psec-wide 1.32 micron Nd(3+):YAG laser pulses, mode-locked KCl:Na(+):O2(-) (F2(+)) sub AH color center laser operation with nearly-transform-limited about 5-10 psec-wide pulses throughout a 1.73-2.10-micron tuning range are realized. Pulses shorten continuously with increasing pump power levels. At maximum available pump power (about 2.3 W), average output power up to about 380 mW is obtained in the peak of the tuning curve at 1.83 micron. Pulse shape and width measurements show that stable-mode-locked operation is relatively insensitive toward cavity-length detuning. All observed mode-locking characteristics are in good qualitative agreement with theoretical predictions for a synchronously pumped material in which the fluorescence-decay-time is large compared with the cavity round trip time. The new laser provides a high average-power picosecond light source in a wavelength range where only few competing laser systems exist.

Moellmann, K.; Mitschke, F.; Welling, H.; Gellermann, W.

324

Visible and near-IR spectroscopic studies of uranium(IV) oxychloride in a MgCl{sub 2}-KCl melt  

SciTech Connect

Although the chemistry of uranium(IV) chloride complexes in molten chloride melts has been widely investigated, no studies of uranium(IV) oxychloride complexes in these melts have appeared, with the exception of a recent paper from this laboratory. In that paper, visible and near-IR absorption bands overlapping with those of the uranium(IV) chloride complex are attributed to oxychloride species. Attempts have been made to prepare solutions containing uranium oxychloride by a direct dissolution of UOCl{sub 2} into solvents such as water, acids, and molten pyridinium chloride. However, only uranium(IV) chloride complex species are recovered. This led Ewing to conclude that the uranium-oxygen bond in UOCl{sub 2} is stabilized only in the solid state probably by the lattice energy of the crystal. Here the authors want to report, for the first time, the visible and near-IR spectra of uranium oxychloride in molten MgCl{sub 2}-KCl without interference from those of uranium(IV) chloride complexes. In addition, experimental evidence is provided to confirm that the new uranium(IV) species is an oxygen-containing chloride complex.

Dai, S.; Toth, L.M.; Del Cul, G.D.; Metcalf, D.H. [Oak Ridge National Lab., TN (United States)

1995-01-04

325

Experimental Na/K exchange between alkali feldspar and an NaCl-KCl salt melt: chemically induced fracturing and element partitioning  

NASA Astrophysics Data System (ADS)

The exchange of Na+ and K+ between alkali feldspar and a NaCl-KCl salt melt has been investigated experimentally. Run conditions were at ambient pressure and 850 °C as well as 1,000 °C. Cation exchange occurred by interdiffusion of Na+ and K+ on the feldspar sub-lattice, while the Si-Al framework remained unaffected. Due to the compositional dependence of the lattice parameters compositional heterogeneities resulting from Na+/K+ interdiffusion induced coherency stress and associated fracturing. Depending on the sense of chemical shift, different crack patterns developed. For the geometrically most regular case that developed when potassic alkali feldspar was shifted toward more sodium-rich compositions, a prominent set of cracks corresponding to tension cracks opened perpendicular to the direction of maximum tensile stress and did not follow any of the feldspar cleavage planes. The critical stress needed to initiate fracturing in a general direction of the feldspar lattice was estimated at ?0.35 GPa. Fracturing provided fast pathways for penetration of salt melt or vapor into grain interiors enhancing overall cation exchange. The Na/K partitioning between feldspar and the salt melt attained equilibrium values in the exchanged portions of the grains allowing for extraction of the alkali feldspar mixing properties.

Neusser, G.; Abart, R.; Fischer, F. D.; Harlov, D.; Norberg, N.

2012-08-01

326

Optical properties of Eu2+-ions immersed as substitutional impurities in a novel spatially-coherent composite host obtained from a melt of KCl, KBr and KI  

NASA Astrophysics Data System (ADS)

The optical properties of doping Eu2+-ions in a novel composite host, consisting of a spatially-coherent aggregate of crystallites of KBr(0.097):KI(0.903) and KBr(0.459):KCl(0.511):KI(0.030), are investigated. The absorption spectrum consists of two broad absorption bands peaking at 353 and 279 nm while the fluorescence spectrum has a single emission band peaking at 422 nm. These spectra, formed by the spectral contributions from the phases in the composite, are similar in overall shape to the spectra of the Eu2+-doped alkali halides used as mother salts, indicating that they are similar in electronic origin. However, in relation to these alkali halides, the phases in the Eu2+-doped composite have low 10Dq-splittings (5684 and 8034 cm-1), low 5d-level barycentre shifts (corresponding to decrements of about -3351, -2839, and -1823 cm-1, respectively, for one of the phases in the composite, and -2411, -1899 and -916 cm-1, respectively, for the other) and low Stokes shifts (4632 and 5496 cm-1). Such low values are discussed to be due to the effect of the mixed ionic character of the impurity environment on the local crystal field as well as to an impurity preference for host cation lattice sites where an iodide ion is nearby to lie at.

Cordero-Borboa, A. E.; Flores-Jiménez, C.; Campos-González, M. A.; Hernández-Alcántara, J. M.; Murrieta-Sánchez, H.

2012-10-01

327

Application of a boron doped diamond (BDD) electrode as an anode for the electrolytic reduction of UO2 in Li2O-LiCl-KCl molten salt  

NASA Astrophysics Data System (ADS)

A boron doped diamond thin film electrode was employed as an inert anode to replace a platinum electrode in a conventional electrolytic reduction process for UO2 reduction in Li2O-LiCl molten salt at 650 °C. The molten salt was changed into Li2O-LiCl-KCl to decrease the operation temperature to 550 °C at which the boron doped diamond was chemically stable. The potential for oxygen evolution on the boron doped diamond electrode was determined to be approximately 2.2 V vs. a Li-Pb reference electrode whereas that for Li deposition was around -0.58 V. The density of the anodic current was low compared to that of the cathodic current. Thus the potential of the cathode might not reach the potential for Li deposition if the surface area of the cathode is too wide compared to that of the anode. Therefore, the ratio of the surface areas of the cathode and anode should be precisely controlled. Because the reduction of UO2 is dependent on the reaction with Li, the deposition of Li is a prerequisite in the reduction process. In a consecutive reduction run, it was proved that the boron doped diamond could be employed as an inert anode.

Park, Wooshin; Kim, Jong-Kook; Hur, Jin-Mok; Choi, Eun-Young; Im, Hun Suk; Hong, Sun-Seok

2013-01-01

328

WNK Protein Kinases Modulate Cellular ClÃÂ Flux by Altering the Phosphorylation State of the Na-K-Cl and K-Cl Cotransporters  

NSDL National Science Digital Library

Precise control of cellular ClÃÂ transport is necessary for many fundamental physiological processes. For example, the intracellular concentration of ClÃÂ, fine-tuned through the coordinated action of cellular ClÃÂ influx and efflux mechanisms, determines whether a neuronÃÂs response to GABA is excitatory or inhibitory. In epithelia, synchrony between apical and basolateral ClÃÂ flux, and transcellular and paracellular ClÃÂ transport, is necessary for efficient transepithelial ClÃÂ reabsorption or secretion. In cells throughout the body, coordination of ClÃÂ entry and exit mechanisms help defend against changes in cell volume. The Na-K-Cl and K-Cl cotransporters of the SLC12 gene family are important molecular determinants of ClÃÂ entry and exit, respectively, in these systems. The WNK serine-threonine kinase family, members of which are mutated in an inherited form of human hypertension, are components of a signaling pathway that coordinates ClÃÂ influx and efflux through SLC12 cotransporters to dynamically regulate intracellular ClÃÂ activity.

Dr. Gerardo Gamba (Universidad Nacional Autónoma de México Molecular Physiology Unit, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán)

2006-10-01

329

A regulatory role of K(+)-Cl(-) cotransporter in the cell cycle progression of breast cancer MDA-MB-231 cells.  

PubMed

K(+)-Cl(-) cotransporter (KCC) has been shown to be involved in cell proliferation as well as cell volume regulation. A regulatory role of KCC in cell cycle progression of breast cancer MDA-MB-231 cells was explored by using synchronized MDA-MB-231 cells and dihydro-indenyloxy-alkanoic acid (DIOA), a potent inhibitor of KCC. MDA-MB-231 cells cultured in the presence of DIOA exhibited an increase in cell volume, a decrease in intracellular Cl(-) concentration, and reduction in cell proliferation with the G0/G1 phase arrest, which was accompanied with down-regulation of cyclin D1 and cyclin E2, and up-regulation of p21. Among these molecules, the expression of cyclin E2, a molecule essential for the transition from G1 to S phase, was markedly suppressed by DIOA treatment. DIOA-mediated up- or down-regulation of these molecules occurred at the transcriptional level. These findings suggest that KCC plays an important role in the early phase of cell cycle progression by regulating the expression of cyclin D1, cyclin E2, and p21, the molecules essential for the cell cycle progression. PMID:23831333

Kitagawa, Maki; Niisato, Naomi; Shiozaki, Atsushi; Ohta-Fujimoto, Mariko; Hosogi, Shigekuni; Miyazaki, Hiroaki; Ichikawa, Daisuke; Otsuji, Eigo; Marunaka, Yoshinori

2013-07-02

330

Corrosion inhibition of mild steel by natural product compound  

Microsoft Academic Search

Corrosion inhibition of mild steel in H3PO4 containing chloride or sulphate ions have been studied using different electrochemical techniques. The corrosion and hydrogen evolution of mild steel alloy in 2M H3PO4 acid containing 0.5M NaCl can be effectively inhibited by addition of natural product compound, Thymol (IPMP), of different concentrations. However, in 2M H3PO4 containing 0.5M Na2SO4 corrosion cannot be

M. A. Ameer; A. M. Fekry

2011-01-01

331

Speciation of the Ternary Complexes of Vanadium(III)–Dipicolinic Acid with the Amino Acids Glycine, Proline, ? Alanine and ? Alanine Studied in 3.0 mol?dm ?3 KCl at 25?°C  

Microsoft Academic Search

In this paper we present speciation results for the ternary vanadium(III)–dipicolinic acid (H2dipic) systems with the amino acids glycine (Hgly), proline (Hpro), ?-alanine (H?-ala), and ?-alanine (H?-ala), obtained by means of electromotive forces measurements emf(H) using 3.0 mol?dm?3 KCl as the ionic medium and a temperature of 25?°C. The experimental data were analyzed by means of the computational least-squares\\u000a program LETAGROP,

Carmen Batista; José Daniel Martínez; Mary Lorena Araujo; Felipe Brito; Giuseppe Lubes; Mildred Rodríguez; Vito Lubes

2011-01-01

332

Gas hydrates of methane, ethane, propane, and carbon dioxide in the presence of single NaCl, KCl, and CaCl 2 aqueous solutions: Experimental measurements and predictions of dissociation conditions  

Microsoft Academic Search

Experimental dissociation data for methane, ethane, propane, and carbon dioxide simple hydrates in the presence of NaCl, KCl, and CaCl2 aqueous solutions with different concentrations of single salt are reported in this communication. The experimental data were generated using a reliable isochoric technique. Some of the experimental hydrate dissociation data measured in this study are compared with some selected experimental

Amir H. Mohammadi; Waheed Afzal; Dominique Richon

2008-01-01

333

Activity coefficients of glycine in aqueous electrolyte solutions: experimental data for (H 2 O + KCl + glycine) at T = 298.15 K and (H 2 O + NaCl + glycine) at T = 308.15 K  

Microsoft Academic Search

Electrochemical cells with two ion-selective electrodes against a single-junction reference electrode were used to obtain the activity coefficients of glycine in aqueous electrolyte solutions. Activity coefficient data were presented for {H2O + KCl (mS) + glycine (mA)}, and {H2O + NaCl (mS) + glycine (mA)} atT= 298.15 K and T= 308.15 K, respectively. The results show that the presence of

M. K. Khoshkbarchi

2001-01-01

334

RAPID COMMUNICATION: Electrical transport properties of bulk MgB2 materials synthesized by electrolysis on fused mixtures of MgCl2, NaCl, KCl and MgB2O4  

Microsoft Academic Search

Bulk MgB2 materials have been synthesized electrochemically from fused mixtures of MgCl2, NaCl, KCl and MgB2O4 under an Ar flow at 600 °C. Electrical resistivity measurements for the samples show an onset of superconducting transition at ~37 K in the absence of an applied magnetic field. This temperature is quite close to that observed from magnetic measurements. The resistivity decreases

Kenji Yoshii; Hideki Abe

2002-01-01

335

Detection of antibodies to hepatitis C virus (anti-HCV) in patients with various liver diseases, by an ELISA (KCL-163) test consisting of synthetic peptides corresponding to an HCV genome  

Microsoft Academic Search

Summary  In 1989, the Chiron group developed an enzyme immunoassay system (C100) for detecting antibodies to hepatitis C virus (anti-HCV).\\u000a In our examinations, the postivie rate was 65.3% of the total number of patients (199) with non-A, non-B (NANB) liver disease.\\u000a Additionally, a specific ELISA system (KCL-163) was developed by Kaketsuken (Kumamoto, Japan) based on synthetic peptides\\u000a corresponding to an HCV

Shin-ichi Kawano; Shigetoshi Fujiyama; Shinjiro Sato; Ken Yoshida; Junji Shibata; Hiroshi Murata; Tetsuo Kawahara; Kyosuke Mizuno; Saneo Nonaka; Tatsuo Sato

1991-01-01

336

Experimental and simulation study of salt effects and pressure\\/density effects on oxygen and hydrogen stable isotope liquid-vapor fractionation for 4–5 molal aqueous NaCl and KCl solutions to 400°C  

Microsoft Academic Search

Liquid-vapor equilibrium fractionation factors for D\\/H and 18O\\/16O exchange between concentrated (4.0 to 4.8 molal) aqueous solutions of NaCl and KCl and their respective equilibrium vapor phases have been determined experimentally up to 413°C. In both cases, strong deviations from the pure water liquid-vapor fractionation curves are observed. The D\\/H fractionation curves of the two salt solutions are almost identical

T. Driesner; T. M Seward

2000-01-01

337

Electrodeposition of Lu on W and Al electrodes: Electrochemical formation of Lu–Al alloys and oxoacidity reactions of Lu(III) in the eutectic LiCl–KCl  

Microsoft Academic Search

The electrodeposition of lutetium on inert electrodes and the formation of lutetium–aluminium alloys were investigated in the eutectic LiCl–KCl in the temperature range 673–823K. On a tungsten electrode, the electroreduction of Lu(III) proceeds in a single step and electrocrystalization plays an important role. Experimental current–time transients are in good agreement with theoretical models based on either instantaneous or progressive nucleation

M. R. Bermejo; E. Barrado; A. M. Martínez; Y. Castrillejo

2008-01-01

338

A high-pressure conductivity and laser Raman spectroscopic study of aqueous orthophosphate solutions at 25 °C  

Microsoft Academic Search

Conductivities of aqueous solutions of H3PO4, KH2PO4, and Na3PO4 (0.001–1 M), and Raman spectra of 0.1, 0.5, 10, and 15.5 M H3PO4, 1 M KH2PO4, and 0.1M Na3PO4, have been obtained at 25 °C, and pressures up to 200 MPa. Pressure enhanced the first dissociation of H3PO4 (?p\\/??, measured by conductivity vs [H3PO4] goes through a maximum), and reduced the

W. A. Adams; Caroline M. Preston; H. A. M. Chew

1979-01-01

339

A high-pressure conductivity and laser Raman spectroscopic study of aqueous orthophosphate solutions at 25 °C  

Microsoft Academic Search

Conductivities of aqueous solutions of H3PO4, KH2PO4, and Na3PO4 (0.001-1 M), and Raman spectra of 0.1, 0.5, 10, and 15.5 M H3PO4, 1 M KH2PO4, and 0.1M Na3PO4, have been obtained at 25 °C, and pressures up to 200 MPa. Pressure enhanced the first dissociation of H3PO4 (kappap\\/kappa?, measured by conductivity vs [H3PO4] goes through a maximum), and reduced the

W. A. Adams; Caroline M. Preston; H. A. M. Chew

1979-01-01

340

Reactivity of NH4H2PO4 toward LaCl3 in LiCl-KCl melt flux. Step by step formation of monazite-like LaPO4.  

PubMed

The synthesis of lanthanum phosphates in molten LiCl-KCL eutectic was chosen to address the preliminary treatment of chlorinated wastes containing fission products that are already present in a Li/Cl eutectic. The obtained monazite compound shows interesting properties to be considered as a good candidate to trap lanthanum for a long-time. The synthesis route based on LaCl(3) reaction with NH(4)H(2)PO(4) in a stoichiometric amount is a key point to obtain monazite as a pure phase. Hence, the salt composition is not modified during the synthesis reaction. The chemical reactivity of ammonium dihydrogenphosphate (NH(4)H(2)PO(4), hereafter abbreviated ADP) toward lanthanum chloride (LaCl(3)) in molten LiCl-KCl eutectic is probed by NMR spectroscopy to follow the formation of LaPO(4). Formally, a direct transformation of the two aforementioned precursors into LaPO(4), NH(4)Cl and HCl can be discarded on the basis of the low thermal stability of ADP. To shed some light on the formation of LaPO(4), in situ and ex situ NMR experiments were carried out on LiCl-KCl/LaCl(3)/ADP, as well as LiCl-KCl/ADP, KCl/ADP, and LiCl/ADP mixtures. First, the reactivity of the precursors in contact with the eutectic was studied from room temperature to 600 degrees C by means of (31)P, (35)Cl, and (139)La high temperature NMR. Second, ex situ room temperature magic angle spinning (MAS) and RadioFrequency driven recoupling (RFDR) (31)P solid-state NMR experiments were carried out on solid samples prepared in different conditions (i.e., temperature and atmosphere) and quenched at room temperature to identify frozen intermediate species in their metastable state. On the basis of this approach, we propose a model for the LaPO(4) formation based on a multistep mechanism which highlights the strong reactivity of ADP toward the alkaline salts but without final change in the composition of the solvent. PMID:19572720

Hudry, Damien; Rakhmatullin, Aydar; Bessada, Catherine; Bardez, Isabelle; Bart, Florence; Jobic, Stéphane; Deniard, Philippe

2009-08-01

341

Role of an apical K,Cl cotransporter in urine formation by renal tubules of the yellow fever mosquito (Aedes aegypti).  

PubMed

The K,Cl cotransporters (KCCs) of the SLC12 superfamily play critical roles in the regulation of cell volume, concentrations of intracellular Cl(-), and epithelial transport in vertebrate tissues. To date, the role(s) of KCCs in the renal functions of mosquitoes and other insects is less clear. In the present study, we sought molecular and functional evidence for the presence of a KCC in renal (Malpighian) tubules of the mosquito Aedes aegypti. Using RT-PCR on Aedes Malpighian tubules, we identified five alternatively spliced partial cDNAs that encode putative SLC12-like KCCs. The majority transcript is AeKCC1-A(1); its full-length cDNA was cloned. After expression of the AeKCC1-A protein in Xenopus oocytes, the Cl(-)-dependent uptake of (86)Rb(+) is 1) activated by 1 mM N-ethylmaleimide and cell swelling, 2) blocked by 100 ?M dihydroindenyloxyalkanoic acid (DIOA), and 3) dependent upon N-glycosylation of AeKCC1-A. In Aedes Malpighian tubules, AeKCC1 immunoreactivity localizes to the apical brush border of principal cells, which are the predominant cell type in the epithelium. In vitro physiological assays of Malpighian tubules show that peritubular DIOA (10 ?M): 1) significantly reduces both the control and diuretic rates of transepithelial fluid secretion and 2) has negligible effects on the membrane voltage and input resistance of principal cells. Taken together, the above observations indicate the presence of a KCC in the apical membrane of principal cells where it participates in a major electroneutral transport pathway for the transepithelial secretion of fluid in this highly electrogenic epithelium. PMID:21813871

Piermarini, Peter M; Hine, Rebecca M; Schepel, Matthew; Miyauchi, Jeremy; Beyenbach, Klaus W

2011-08-03

342

Kinetics of activation and inactivation of swelling-stimulated K+/Cl- transport. The volume-sensitive parameter is the rate constant for inactivation  

PubMed Central

Red blood cells of several species are known to exhibit a ouabain- insensitive, anion-dependent K+ (Rb+) flux that is stimulated by cell swelling. We have used rabbit red cells to study the kinetics of activation and inactivation of the flux upon step changes in tonicity. Sudden hypotonic swelling (210 mosmol) activates the flux after a lag period of 10 min at 37 degrees C and 30-50 min at 25 degrees C. In cells that were preswollen to activate the transporter, sudden shrinkage (by addition of hypertonic NaCl) causes a rapid inactivation of the flux; the time lag for inactivation is less than 2 min at 37 degrees C. A minimal model of the volume-sensitive KCl transport system requires two states of the transporter. The activated (A) state catalyzes transport at some finite rate (turnover number unknown because the number of transporters is unknown). The resting (R) state has a much lower or possibly zero transport rate. The interconversion between the states is characterized by unimolecular rate constants R k12 in equilibrium with k21 A. The rate of relaxation to any new steady state is equal to the sum of the rate constants k12 + k21. Because the rate of transport activation in a hypotonic medium is lower than the rate of inactivation in an isotonic medium, we conclude that the volume- sensitive rate process is inactivation (the A to R transition); that is, cell swelling activates transport by lowering k21. Three phosphatase inhibitors (fluoride, orthovanadate, and inorganic phosphate) all inhibit the swelling-activated flux and also slow down the rate of approach to the swollen steady state. This finding suggests that a net dephosphorylation is necessary for activation of the flux and that the net dephosphorylation takes place as a result of swelling- induced inhibition of a kinase rather than stimulation of a phosphatase.

1990-01-01

343

I-NERI ANNUAL TECHNICAL PROGRESS REPORT: 2006-002-K, Separation of Fission Products from Molten LiCl-KCl Salt Used for Electrorefining of Metal Fuels  

SciTech Connect

An attractive alternative to the once-through disposal of electrorefiner salt is to selectively remove the active fission products from the salt and recycle the salt back to the electrorefiner (ER). This would allow salt reuse for some number of cycles before ultimate disposal of the salt in a ceramic waste form. Reuse of ER salt would, thus, greatly reduce the volume of ceramic waste produced during the pyroprocessing of spent nuclear fuel. This final portion of the joint I-NERI research project is to demonstrate the separation of fission products from molten ER salt by two methods previously selected during phase two (FY-08) of this project. The two methods selected were salt/zeolite contacting and rare-earth fission product precipitation by oxygen bubbling. The ER salt used in these tests came from the Mark-IV electrorefiner used to anodically dissolved driver fuel from the EBR-II reactor on the INL site. The tests were performed using the Hot Fuel Dissolution Apparatus (HFDA) located in the main cell of the Hot Fuels Examination Facility (HFEF) at the Materials and Fuels complex on the INL site. Results from these tests were evaluated during a joint meeting of KAERI and INL investigators to provide recommendations as to the future direction of fission product removal from electrorefiner salt that accumulate during spent fuel treatment. Additionally, work continued on kinetic measurements of surrogate quaternary salt systems to provide fundamental kinetics on the ion exchange system and to expand the equilibrium model system developed during the first two phases of this project. The specific objectives of the FY09 I-NERI research activities at the INL include the following: • Perform demonstration tests of the selected KAERI precipitation and INL salt/zeolite contacting processes for fission product removal using radioactive, fission product loaded ER salt • Continue kinetic studies of the quaternary Cs/Sr-LiCl-KCl system to determine the rate of ion exchange during the salt/zeolite contacting process • Compare the adsorption models to experimentally obtained, ER salt results • Evaluate results obtained from the oxygen precipitation and salt/zeolite ion exchange studies to determine the best processes for selective fission-product removal from electrorefiner salt.

S. Frank

2009-09-01

344

Speciation of the Ternary Complexes of Vanadium(III)–Dipicolinic Acid and the Amino Acids Cysteine, Histidine, Aspartic and Glutamic Acids in 3.0 mol?dm ?3 KCl at 25?°C  

Microsoft Academic Search

In this work we present results for the speciation of the ternary complexes formed in the aqueous vanadium(III)–dipicolinic\\u000a acid and the amino acids cysteine (H2cys), histidine (Hhis), aspartic acid (H2asp) and glutamic acid (H2glu) systems (25?°C; 3.0 mol?dm?3 KCl as ionic medium), determined by means of potentiometric measurements. The potentiometric data were analyzed with the\\u000a least-squares program LETAGROP, taking into

Isaida Shiozawa; Giuseppe Lubes; Mildred Rodríguez; Vito Lubes

2011-01-01

345

Salting effect of NaCl and KCl on the liquid-liquid equilibria of water plus ethyl acetate plus ethanol system and interaction parameters estimation using the genetic algorithm  

Microsoft Academic Search

Salting effect of NaCl and KCl on the liquid-liquid equilibria (LLE) of\\u000a water-ethyl acetate-ethanol system was investigated experimentally at\\u000a 293.15 K and 1 atm. The salt mass percentages considered were 5 and\\u000a 10\\\\%. The results show that the two electrolytes significantly affected\\u000a the solubility of the solute in the organic phase, since its\\u000a distribution coefficient increased with rising amount of

A. Hasseine; A. Kabouche; A.-H. Meniai; M. Korichi

2011-01-01

346

Temperature dependence of the f?f hypersensitive transitions of Ho3+ and Nd3+ in molten salt solvents and the structure of the LaCl3 KCl melts  

NASA Astrophysics Data System (ADS)

The electronic absorption spectra of the hypersensitive transitions 5G6?5I8 of Ho3+ and 4G5/2?4I9/2 of Nd3+ have been measured in molten LiCl KCl eutectic and in LaCl3 KCl molten mixtures. The ligand field components of the above transitions in octahedral symmetry have been identified and the molar absorptivity changes with temperature and composition have been measured. The spectra are discussed in terms of the coordination geometries of the probe cations Ho3+ and Nd3+ in these molten salt solvents. The Boltzmann thermal factor appears to be responsible in part for the variation of the ‘hot’ band intensities. The data suggest that the predominant factors affecting the oscillator strength of the Ho3+ and Nd3+ hypersensitive transitions is the degree of octahedral distortions in conjunction with the overall charge asymmetry around the LnCl63- (Ln=Ho, Nd). It appears that no drastic changes occur in the coordination of the probe cations as we go from dilute in LaCl3 to pure LaCl3 melts; this suggests that in the host melt the coordination of La3+ is more likely to be six-fold. A further evidence for the six-fold coordination is given by the measured Judd Ofelt parameters of Nd3+ in both molten NdCl3 and La(Nd)Cl3.

Chrissanthopoulos, A.; Papatheodorou, G. N.

2006-01-01

347

Enhanced bioactivity and osteoconductivity of hydroxyapatite through chloride substitution.  

PubMed

The effect of chloride-substitution on bioactivity and osteoconductivity of hydroxyapatite (OHAp) was newly investigated. Chloride-substituted hydroxyapatites (ClAp) with low and high chloride concentrations were synthesized by reacting Ca(OH)2 and H3 PO4 with NH4 Cl of low and high concentrations, with subsequent sintering. As a control, pure OHAp was prepared under the same conditions but without addition of NH4 Cl. The ClAp showed markedly enhanced bioactivity in simulated body fluid (SBF) as the chloride substitution was increased. In contrast, OHAp did not show any bioactivity at all within the testing period. The solubility tests in deionized water also showed that the higher the chloride-substituting amount, the higher the dissolution amounts of the constituent elements of apatite, which directly affect bioactivity by increasing the degree of supersaturation of apatite in SBF. In addition, ClAp also showed noticeably higher osteoconductivity within the 4 weeks of implantation in calvarial defects of New Zealand white rabbits, compared with that of OHAp. The total system energy of the apatite calculated by the ab initio method showed that the higher the chloride-substituting amount, the higher the total system energy, which suggests that the ClAp was energetically less stable compared with OHAp. This result demonstrates the higher solubility of ClAp over that of OHAp in SBF and deionized water. The improved solubility of the OHAp enhances its bioactivity and consequent osteoconductivity. Taken together, it can be concluded that ClAp has encouraging potential for use as a bone grafting material due to its highly enhanced bioactivity and osteoconductivity compared with pure OHAp. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. PMID:23533198

Cho, Jung Sang; Yoo, Dong Su; Chung, Yong-Chae; Rhee, Sang-Hoon

2013-03-27

348

Viscosities of l-Histidine/ l-Glutamic Acid/ l-Tryptophan/Glycylglycine + 2 M Aqueous KCl/KNO3 Solutions at T = (298.15 to 323.15) K  

NASA Astrophysics Data System (ADS)

Viscosity values of l-histidine/ l-glutamic acid/ l-tryptophan/glycylglycine + 2 M aqueous KCl/KNO3 solutions have been determined experimentally as a function of molal concentration of amino acid/peptide at different temperatures: (298.15, 303.15, 308.15, 313.15, 318.15, and 323.15) K. Using the viscosity values of the solvent and solution, the relative viscosity, specific viscosity, and viscosity B-coefficient values have been computed. The trends of the variation of experimental and computed parameters with the solute concentration and temperature have been interpreted in terms of zwitterions-ions, zwitterions-water dipoles, ions-water dipoles, and ions-ions interactions operative in the systems.

Riyazuddeen; Altamash, Tausif

2011-06-01

349

Molten salt extraction (MSE) of americium from plutonium metal in CaCl{sub 2}-KCl-PuCl{sub 3} and CaCl{sub 2}-PuCl{sub 3} salt systems  

SciTech Connect

Molten salt extraction (MSE) of americium-241 from reactor-grade plutonium has been developed using plutonium trichloride salt in stationary furnaces. Batch runs with oxidized and oxide-free metal have been conducted at temperature ranges between 750 and 945C, and plutonium trichloride concentrations from one to one hundred mole percent. Salt-to-metal ratios of 0.10, 0.15, and 0 30 were examined. The solvent salt was either eutectic 74 mole percent CaCl{sub 2}{endash}26 mole percent KCl or pure CaCl{sub 2}. Evidence of trivalent product americium, and effects of temperature, salt-to-metal ratio, and oxide contamination on the americium extraction efficiency are given. 24 refs, 20 figs, 13 tabs.

Dodson, K.E.

1992-06-11

350

The effect of NaCl substitution with KCl on Akawi cheese: chemical composition, proteolysis, angiotensin-converting enzyme-inhibitory activity, probiotic survival, texture profile, and sensory properties.  

PubMed

The effect of partial substitution of NaCl with KCl on Akawi cheese with probiotic bacteria was investigated during 30 d of storage at 4 °C. Chemical composition, the survival of probiotic and lactic acid bacteria, proteolytic activity, and texture profile analysis were analyzed and sensory analysis was carried out to determine the effects of substitution. No significant differences were observed in moisture, protein, fat, and ash contents among the experimental Akawi cheeses at the same storage period. Significant differences were observed in water-soluble nitrogen and phosphotungstic-soluble nitrogen between experimental cheeses at the same of storage period. No significant difference was observed in the growth of Lactobacillus delbrueckii ssp. bulgaricus between experimental cheeses at the same storage period. However, the growth of Streptococcus thermophilus, Lactobacillus casei, and Lactobacillus acidophilus was significantly affected among experimental cheeses. A significant difference was observed in soluble Ca among experimental cheeses at the same storage period. In general, no significant differences existed in hardness and adhesiveness among experimental cheeses at the same storage period. No significant differences existed in sensory attributes, including creaminess, bitterness, saltiness, sour-acid, and vinegar taste among experimental Akawi cheeses at the same storage period. PMID:22916878

Ayyash, M M; Sherkat, F; Shah, N P

2012-09-01

351

Phosphate-induced metal immobilization in a contaminated site  

Microsoft Academic Search

To assess the efficiency of P-induced metal immobilization in soils, a pilot-scale field experiment was conducted at a metal contaminated site located in central Florida. Phosphate was applied at a P\\/Pb molar ratio of 4.0 with three treatments: 100% of P from H3PO4, 50% of P from H3PO4+ 50% of P from Ca(H2PO4)2, and 50% of P from H3PO4+5% phosphate

Rocky X. Cao; Lena Q. Ma; Ming Chen; Satya P. Singh; Willie G. Harris

2003-01-01

352

Melting behavior of fluid inclusions in laboratory-grown halite crystals in the systems NaCl?H 2O, NaCl?KCl?H 2O, NaCl?MgCl 2?H 2O, and NaCl?CaCl 2?H 2O  

NASA Astrophysics Data System (ADS)

The chemical composition of aqueous fluid inclusions in crystals of halite can be accurately determined from observed melting behaviors of ice, hydrohalite, and sylvite. Some fluid inclusion melting behaviors observed in laboratory-grown halite crystals (systems NaCl?H 2O, NaCl?KCl?H 2O, NaCl?MgCl 2? H 2O, and NaCl?CaCl 2?H 2O) differ from predicted stable equilibrium relations. In the NaCl?H 2O and NaCl?KCl?H 2O systems, observed first melt temperatures are up to 15°C below the equilibrium eutectic temperatures of -21.2° and -22.9°C, respectively. The final melting temperature of ice, in the presence of hydrohalite, and the final melting temperature of hydrohalite are reproducible and match predicted melting temperatures. The limit of detection of sylvite daughter crystals in the NaCl?KCl?H 2O system is approximately 5 wt% (? 1 molal) KCl. Final melting temperatures of sylvite match published equilibrium data to within 0.3°C. In the NaCl?KCl?H 2O system at halite saturation, m KCl can be determined from the final sylvite dissolution temperature or from the final melting temperature of hydrohalite. Fluid inclusions in the NaCl?MgCl 2?H 2O and NaCl?CaCl 2?H 2O systems that form stable salt hydrates (MgCl 2 · 12H 2O and CaCl 2 · 6H 2O) during freezing first melt within 3°C of predicted eutectic temperatures (-37° and -52°C). However, fluid inclusions with MgCl 2 or CaCl 2 may also start melting at temperatures as low as -80°C. Such low first melt temperatures indicate the presence of metastable salt hydrates (presumably MgCl 2 · 8H 2O, MgCl 2 · 6H 2O or CaCl 2 · 4H 2O). The formation of metastable phases during freezing of fluid inclusions can lead to misinterpretation of the chemical composition of fluid inclusions in natural samples. This is especially true for fluid inclusions with first melt temperatures below -37°C which may be erroneously interpreted as being rich in CaCl 2. The final melting of ice in the presence of hydrohalite may vary by more than 15°C in fluid inclusions of different size but identical bulk composition, and occurs at lower temperatures than predicted in fluid inclusions from the NaCl?MgCl 2?H 2O and NaCl?CaCl 2?H 2O systems. However, the final melting temperature of ice in inclusions which fail to nucleate hydrohalite, and the final melting temperature of hydrohalite are reproducible to within ±0.1 ° C and can be used to determine MgCl 2 and CaCl 2 molalities.

Davis, Daniel W.; Lowenstein, Tim K.; Spencer, Ronald J.

1990-03-01

353

FEATHER AND HAIR MEALS FOR RUMINANTS. IV. EFFECTS OF CHEMICAL TREATMENTS OF FEATHERS AND PROCESSING TIME ON DIGESTIBILITY 1'2  

Microsoft Academic Search

Summary Chicken feathers were treated with various concentrations of NaOH or H3PO4 and then steam processed in a laboratory autoclave. In vitro pepsin digestibility (IVPD) of laboratory hydrolyzed feather meal (FM) increased (P<.05) as processing time and as NaOH (P<.O05) or H3PO4 (P<.05) concentration increased. There was an interaction (P<.05) between chemical treatment and processing time. Crude protein (CP) levels

R. J. Steiner; R. O. Kellems; D. C. Church

354

Phosphoric acid activation of Morrocan oil shale of Timahdit: Influence of the experimental conditions on yield and surface area of adsorbents  

NASA Astrophysics Data System (ADS)

The use of Moroccan oil shale for the preparation of adsorbents by chemical activation with phosphoric acid is analysed. The results indicate that this material is promising for this application. The effect of different conditions of preparation on the yield and surface area is discussed. These parameters are H{3}PO{4}/shale weight ratio, carbonisation temperature, carbonisation time and concentration of H{3}PO{4}.

Ichcho, S.; Khouya, E.; Abourriche, A.; Ezzine, M.; Hannache, H.; Naslain, R.; Pailler, R.

2005-03-01

355

Modeling the electric transport of sulfuric and phosphoric acids through anion-exchange membranes  

Microsoft Academic Search

The electric transport of the H2SO4 and H3PO4 mixture through two types of anion-exchange membranes (strong base: ACM; weak base: AAV) was investigated. The H2SO4 removal efficiency from the mixture and the H3PO4 retention efficiency were calculated. It was found that the effectiveness of the separation process is diminished by the association of phosphoric anions with the fixed charges which

Stanis?aw Koter; Monika Kultys

2010-01-01

356

Textural Characterization of Activated Carbons Prepared from Oil-palm Stones Pre-treated with Various Impregnating Agents  

Microsoft Academic Search

Activated carbons with relatively high densities and well-developed porosities were prepared from oil-palm stones which were pre-treated with different types of impregnating agents (ZnCl2, H3PO4 or KOH). The benefits derived from impregnation in terms of higher BET surface areas were generally in the following order: 20% ZnCl2 > 40% H3PO4 > 10% KOH. The textural properties such as density and

Jia Guo; Aik Chong Lua

2000-01-01

357

The dissolution forms of YIG single crystal spheres  

NASA Astrophysics Data System (ADS)

Single crystal spheres of yttrium iron garnet have been dissolved in solvents of H3PO4 and HBr at 140 and 126°C, respectively. The final dissolution form was a tetrahexahedron in H3PO4 and an octahedron in HBr. In the latter case the faces were built up of terraces. The observed dissolution forms could be explained using the theory of Lacmann, Franke and Heimann.

Beregi, E.; Sterk, E.; Tanos, F.; Hartmann, E.; Lábár, J.

1983-12-01

358

Thermal degradation properties of solid polymer electrolyte (poly(vinyl alcohol)+phosphoric acid)\\/methylene blue composites  

Microsoft Academic Search

The thermal stability and degradation of poly(vinyl alcohol) (PVA), PVA+H3PO4 (solid polymer electrolyte, SPE), PVA containing methylene blue (MB) dye and SPE (PVA+H3PO4)+MB were studied by TG\\/DTA\\/DTG and DSC techniques. The FTIR and UV–vis study of these materials indicates that MB forms a complex with the polymer by a hydrogen bonding interaction between the –OH group of the polymer and

Prakash R Somani; R Marimuthu; A. K Viswanath; S Radhakrishnan

2003-01-01

359

An Experimental Study of Magnetite Solubility as a Function of Pressure Along the Dewpoint Curve in the NaCl-, KCl-, HCl-H2O-Melt System.  

NASA Astrophysics Data System (ADS)

Magnetite (Mt) is a ubiquitous phase in magmatic-hydrothermal ore deposits and, thus, any model which aims to predict the evolving physical chemistry of porphyry-ore deposit environments must incorporate data on the equilibria that control the precipitation of Mt in such systems. Extant experimental data indicate that Mt solubility is controlled via the equilibrium Fe3O4Mt + 6HClV + H2V = 3FeCl2V + 4H2OV (Chou and Eugster, 1977, AJS, p 1296); however their experiments were performed at T=500-650° C by equilibrating Mt with a HCl-bearing supercritical aqueous fluid (NaCl-, KCl-free). Conversely, data from some natural Fe-bearing fluid inclusions have evinced that initial temperatures of magmatic volatile phases (MVP) in magmatic-hydrothermal environments may exceed 800° C, possibly even approaching 900° C, in the presence of melt (Clark and Arancibia, 1995, Giant Ore Deposits-II Conference, p. 511). Thus, there currently are no data constraining Mt solubility in the high-temperature regime obtained in natural magmatic systems. Additionally, there are no data on Mt solubility as a function of changes in the chemistry of the MVP. In the system NaCl-H2O, the composition and, thus, the density of brine-saturated vapor change significantly as a function of pressure along a given isotherm and the components KCl and HCl act to shift the limbs of the solvii (Bodnar et al., 1985, GCA, p 1861; Anderko and Pitzer, 1993, GCA, p 1657; Shinohara and Fujimoto, 1994, GCA, p 4857). The absence of data constraining Mt solubility as a function of pressure along a given isotherm, the resultant change in composition and density, as well as deviations in the Na:K:H ratio of the MVP hinder the development of forward models of magmatic-hydrothermal systems. In order to provide these critical data constraining Mt solubility in geologically reasonable magmatic systems we have performed a set of experiments as a function of pressure in the vapor-only field near the 800° C isotherm in the NaCl-H2O system. Natural Mt (aFe3O4 ~1), a synthetic haplogranitic minimum melt (100 MPa) and an aqueous phase (molar K:Na:H=1) were reacted in Au capsules in rapid-quench Stellite-25 vessels, using water as the pressure medium, at 800° C, log fO2 controlled by the NNO buffer, pressures of 100 and 120 MPa, and aqueous salinities of 1.8 and 3.0 wt. % NaCl equivalent, respectively. In all experiments the mass ratio of Mt:melt:fluid was 1:1:4. Detailed petrographic examination of run products did not reveal the presence of brine inclusions; however, fluid inclusions do contain opaque phases. Using the newly determined mFeCl2 (0.0345 at 100 MPa and 0.0359 at 120 MPa) and mHCl (0.0769 at 100 MPa and 0.0947 at 120 MPa) in the quenched MVP and the known fugacities of H2O (? =1) and H2 (? =1) at P and T, apparent equilibrium constants were calculated as log K' = (CFeCl2)3 \\times (fH2O)4 \\div (CHCl)6 \\times fH2. The values of log K' are 1.605 at 100 MPa and 13.01 at 120 MPa. K is fixed for a given P and T except for the effect of activity coefficients for HCl and FeCl2. The values of log K obtained in this study will facilitate more detailed characterization of the chemistry of magmatic-hydrothermal MVPs; both fossil MVPs and those that obtain in modern geothermal reservoirs. Determination of P, T, fH2 and mFeCl2 in fluid inclusions will allow for the direct calculation of a model HCl concentration in the MVP.

Simon, A. C.

2001-12-01

360

Theoretical study on the mechanisms of cellulose dissolution and precipitation in the phosphoric acid-acetone process.  

PubMed

Phosphoric acid-acetone fractionation was applied to pretreat lignocellulose for production of cellulosic ethanol. Cellulose solubility properties in H(2)O, H(3)PO(4) and CH(3)COCH(3) were simulated. Atomic geometry and electronic properties were computed using density functional theory with local-density approximation. H(3)PO(4) molecule is adsorbed between two cellulose segments, forming four hydrogen bonds with E(B) of -1.61 eV. Density of state for cellulose in H(3)PO(4)-cellulose system delocalizes without obvious peak. E(gap) of 4.46 eV is much smaller than that in other systems. Molecular dynamics simulation indicates that fragments of double glucose rings separate in the cellulose-H(3)PO(4) interaction system. Icy CH(3)COCH(3) addition leads to re-gathering of separated fragments. Reaction energy of cellulose in three solvents is around 3.5 eV, implying that cellulose is chemically stable. Moreover, theoretical results correspond to the experiments we have performed, showing that cellulose dissolves in H(3)PO(4), flocculates after CH(3)COCH(3) addition, and finally becomes more liable to be hydrolyzed into glucoses. PMID:22944446

Kang, Peng; Qin, Wu; Zheng, Zong-Ming; Dong, Chang-Qing; Yang, Yong-Ping

2012-08-01

361

Bacterial Quantification in Teeth with Apical Periodontitis Related to Instrumentation and Different Intracanal Medications: A Randomized Clinical Trial  

Microsoft Academic Search

The antibacterial efficacy of intracanal medication with calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX), and a combination of both [Ca(OH)2\\/CHX] was assessed in teeth with chronic apical periodontitis. Thirty-three canals were instrumented, randomly divided into three groups, and medicated with either Ca(OH)2, CHX, or Ca(OH)2\\/CHX. Bacteriological samples obtained from the operative field and the root canals before (S1) and after

Aldo Manzur; Ana Maria González; Amaury Pozos; Daniel Silva-Herzog; Shimon Friedman

2007-01-01

362

Tissue-dissolution capacity and dentin-disinfecting potential of calcium hydroxide mixed with irrigating solutions  

Microsoft Academic Search

ObjectiveThe goal of this study was to compare the tissue-dissolution potential and antibacterial effectiveness of a conventional Ca(OH)2\\/saline paste with equivalent Ca(OH)2\\/NaOCl and Ca(OH)2\\/chlorhexidine digluconate medications.

Matthias Zehnder; Matthias Grawehr; Gunnar Hasselgren; Tuomas Waltimo

2003-01-01

363

Effect of level of acidification by phosphoric acid, storage temperature, and length of storage on the chemical and biological stability of ground poultry mortality carcasses.  

PubMed

Two experiments were conducted to evaluate the addition of feed-grade H3PO4 in comparison to lactic acid fermentation as a means of preserving ground poultry mortality carcasses. Mortality silage quality in both experiments was evaluated by measuring the rise in pH after initial acidification (deltapH) and the content of nonprotein N (NPN), volatile nitrogen (VN), NH3-N, and fecal coliform bacteria in the silage treatments. Preliminary work in Experiment 1 evaluated the preservative effects of six initial levels of acidification with H3PO4 (pH 2.0, 2.5, 3.0, 4.0, or 5.0) at two storage temperatures (21 and 45 C). Experiment 2 compared silages preserved with different levels of feed-grade 74.5% H3PO4 (4.13, 5.52, 6.90, and 8.28% wt/wt, concentrated acid basis) to silages made by lactic acid fermentation. Based on the evaluations in Experiment 1, acidification with H3PO4 to pH < or = 3.0, when incubated at 45 C, or pH < or = 2.0, when incubated at ambient temperatures, produced the most biologically favorable poultry mortality silage for subsequent use as a feed ingredient. In Experiment 2, mortality silages containing 8.28% H3PO4 (wt/wt, concentrated acid basis) contained significantly (P < 0.05) lower levels of the protein degradation by-products VN and NH3-N than silages prepared by lactic acid fermentation. Therefore, feedstuffs manufactured from mortality silages prepared using 8.28% H3PO4 would be expected to result in improved animal performance vs. feedstuffs manufactured using silages prepared by lactic acid fermentation. PMID:11495467

Middleton, T F; Ferket, P R

2001-08-01

364

The solvent extraction of zinc, cadmium and chromium from phosphoric acid solutions by tri- n butyl phosphate in kerosene diluent  

Microsoft Academic Search

In this paper, the solvent extraction of zinc(II), cadmium(II) and chromium(III) from phosphoric acid solutions by tri-n butyl phosphate (TBP) in kerosene as diluent was investigated. The distribution coefficients were determined and the results showed clearly a maximum values at 5.5mol\\/L H3PO4 concentration and a minimum values at 1.0mol\\/L H3PO4 concentration. The apparent standard molar enthalpies ?H° for extraction of

Abdelhamid Mellah; Djafer Benachour

2007-01-01

365

Proposed New Electrolytic Conductivity Primary Standards for KCl Solutions.  

National Technical Information Service (NTIS)

An absolute determination of aqueous electrolytic conductivity has been made for 0.01 molal (m) and 0.1 m potassium chloride solutions, over the temperature range of 0 to 50 C in 5 degree intervals. A cell with a removable center section of accurately kno...

Y. C. Wu W. F. Koch K. W. Pratt

1991-01-01

366

Hat das M -Zentrum in KCL ein magnetisches Moment?  

Microsoft Academic Search

Zusammenfassung Bestrahlt manF-Zentren in Alkalihalogeniden bei Zimmertemperatur mit Licht von der Wellenlänge ihrer Absorptionsbande, so wandeln sie sich in eine Reihe von Folgezentren um; das erste dieser Folgezentren ist dasM-Zentrum. In der vorliegenden Arbeit wird gezeigt, daß dieses Störzentrum kein meßbares Elektronen-spinresonanz-(ESR-) Signal liefert. Hierzu wurden drei voneinander unabhängige Meßmethoden angewendet: 1. Die aus ESR-Absorptionsmessungen bestimmbare Spindichte wurde mit der

H. Gross

1961-01-01

367

Coloration of KCl and KBr Crystals by Far Ultraviolet Radiation.  

National Technical Information Service (NTIS)

F center production by far ultraviolet radiation has been studied in the range of photon energies 40 to 150 eV. Synchrotron radiation was used both for color center production and as a light source for detection. The temperature dependence and efficiency ...

C. Gaehwiller F. C. Brown M. Elango

1970-01-01

368

Characterization of flue gas cleaning residues from European solid waste incinerators: assessment of various Ca-based sorbent processes.  

PubMed

For the first time, a set of samples of European flue gas cleaning residues, mainly from the incineration of municipal solid waste (MSW), has undergone a mineralogical study. The residues are the result of the neutralization of acid flue gases by lime, the predominant method adopted in Europe, using dry and semi-dry washing processes. The study protocol combines physico-chemical analytical techniques (XRD, FTIR, DSC/TGA) and global chemical analysis enabling identification of the chemical composition of the main constituents, particularly chlorinated Ca-based phases, as well as establishment of modal distributions of the represented phases, both crystalline and amorphous. The samples are slightly hydrated and values vary for trapped Cl, S and even CO(2). The main crystalline phases are NaCl, KCl, CaSO(4), CaCO(3), Ca(OH)(2) and calcium hydroxychloride CaOHCl. CaOHCl is the main chlorine phase, regardless of the treatment process, filtration mode, and specific surface of the Ca-based sorbent. This phase develops during neutralization of HCl by excess lime present according to the reaction Ca(OH)(2)+HCl-->CaOHCl+H(2)O, to the detriment of a complete yield involving the two lime OH groups with formation of CaCl(2).2H(2)O. In addition, it seems that gas temperatures above 150 degrees C increase competition between lime-based neutralization of HCl, SO(2) acid flue gases and CO(2) trapping, thus reducing washing efficiency. PMID:12597999

Bodénan, F; Deniard, Ph

2003-05-01

369

Calculated spectroscopy and atmospheric photodissociation of phosphoric acid.  

PubMed

Detection of phosphine (PH(3)) gas in the upper troposphere suggests that the biogeochemical P cycle also includes an atmospheric component that consists of volatile phosphorus-containing molecules. A reasonable end product for the oxidation of PH(3) in the atmosphere is phosphoric acid (H(3)PO(4)). We propose that H(3)PO(4) may be photodissociated into HOPO(2) and H(2)O in the stratosphere, where H(3)PO(4) is likely to be present in gaseous form. We have calculated the energy barrier of this reaction and show that in addition to electronic transitions, OH-stretching overtone transitions can also provide the necessary energy. OH-stretching fundamental and overtone transitions were calculated with the use of an anharmonic oscillator local mode model. The probability of overtone induced photodissociation was estimated with molecular dynamical reaction coordinate simulations. Electronic transitions were calculated with the equation of motion coupled cluster singles doubles method. We have calculated the photodissociation rate constants for absorption of visible, UV, and Lyman-alpha radiation at altitudes from 20 to 100 km. We show that at altitudes between 30 and 70 km, the photodissociation of H(3)PO(4) is likely to proceed via absorption in the UV region by electronic transitions. PMID:20578768

Yekutiel, Mivsam; Lane, Joseph R; Gupta, Priyanka; Kjaergaard, Henrik G

2010-07-22

370

Characterization of adsorbent materials prepared from avocado kernel seeds: Natural, activated and carbonized forms  

Microsoft Academic Search

The development, characterization and application of adsorbents prepared from avocado kernel seeds are described. The preparation comprises physical activation at temperatures up to 1000°C and chemical activation with and without H3PO4, with and without carbonization. The resultant adsorbents have high oxygen content and the main inorganic components are silicon and potassium. After carbonization the surface retains acidic groups, mainly phenolic

María P. Elizalde-González; J. Mattusch; Alejandra A. Peláez-Cid; R. Wennrich

2007-01-01

371

Polysaccharides isolated from sugar beet pulp by quaternization under acidic conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sugar beet pulp was extracted and chemically modified under acidic conditions using glycidyltrimethylammonium chloride in the presence of trifuoroacetic (TFA), HCl or H3PO4. The goal was to find out how the type of acid used and quaternization could affect the yield of soluble polysaccharide, its mo...

372

Polyvinylpyrrolidone and polyethylenimine as inhibitors for the corrosion of a low carbon steel in phosphoric acid  

Microsoft Academic Search

Polarization and weight loss studies showed that both polyvinylpyrrolidonc and polyethylenimine are effective for the inhibition of low carbon steel over a wide concentration range of aqueous phosphoric acid (H3PO4) solutions. Both polymers retard the anodic and cathodic corrosion reactions with emphasis on the former. The results for uninhibited acid confirm the kinetic expression proposed by Mathur and Vasudevan.

Y. Jianguo; W. Lin; V. Otieno-Alego; D. P. Schweinsberg

1995-01-01

373

The Effect on Surface Enamel Fluoride and Dental Caries of Semi-Annual Topical Applications of 0.62 Ammonium Fluoride.  

National Technical Information Service (NTIS)

No inhibition of total caries experience could be detectd after two years as a result of semi-annual topical application of (1) 0.62M NH4F, pH 4.4, preceded by .05M H3PO4 or (2) the standard acidulated phosphate fluoride agent. There may have been a favor...

P. F. DePaola F. Bookstein S. Foley Y. Bakhos P. Soparkar

1975-01-01

374

Influence of the organic solvents on the properties of the phosphoric acid dopant emulsion deposited on multicrystalline silicon wafers  

NASA Astrophysics Data System (ADS)

This study is devoted to the formation of an n+p emitter for multicrystalline silicon (mc-Si) solar cells for photovoltaic (PV) application. The atomization technique has been used to make the emitter from H3PO4 phosphoric acid as a doping source. The doping emulsion has been optimized using several organic solvents. H3PO4 was mixed with one of these solutions: ethanol, 2-butanol, isopropanol alcohol and deionized water. The volume concentration of H3PO4 does not exceed 20% of the total volume emulsion. The deposit characteristics of the emulsion change with the organic solvent. H3PO4 : 2-butanol gives the best deposited layer with acceptable adherence and uniformity on silicon surface. Fourier transform infrared characterizations show the presence of organic and mineral phosphorous bonds in the formed layer. The obtained emitters are characterized by a junction depth in the range 0.2-0.75 µm and a sheet resistance of about 10-90 ?/square. Such a low cost dopant source combined with a continuous spray process can effectively reduce the cost per Wp of the PV generator.

Bouhafs, D.; Moussi, A.; Boumaour, M.; Abaïdia, S. E. K.; Mahiou, L.; Messaoud, A.

2007-05-01

375

Corrosion of Commercial Alloys in Three Environments Simulating Phosphate Rock Acidulation.  

National Technical Information Service (NTIS)

The Bureau of Mines conducted corrosion tests of 18 commercial alloys in H3PO4-phosphate rock or Al2O3 slurry, in 10 pct HF, and in 25 pct H2SiF6 to simulate three environments anticipated in a Bureau process to extract fluoride values from phosphate rock...

L. L. Oden B. D. Nash

1974-01-01

376

Investigation of the phosphoric acid -N,N-dimethylformamide system as potential solvent for cellulose  

Microsoft Academic Search

Viscosity, density, conductivity, solution and mixing enthalpies of the phosphoric acid - N,N-dimethylformamide system were measured over the whole concentration range at temperatures of 25–65°C. The conclusions on the dissociation of phosphoric acid and formation of complexes of H3PO4\\/DMF=21 in the system under investigation were performed.

J. Fadeeva; L. Shmukler; L. Safonova

2003-01-01

377

A comparative study of the thermal decomposition of apple pulp in the absence and presence of phosphoric acid  

Microsoft Academic Search

Apple pulp pyrolysis in the presence of phosphoric acid (chemical activation) represents a promising way for utilisation of this residue from apple juice and cider production. Thermogravimetry and infrared spectroscopy have been used to compare the pyrolysis behaviour of apple pulp, alone and impregnated with 60 wt.% H3PO4. Phosphoric acid promotes the degradation of the biopolymers constituting apple pulp, lowering

F Suárez-Garc??a; A Mart??nez-Alonso; J. M. D Tascón

2002-01-01

378

New iodination of cellulose in phosphoric acid  

Microsoft Academic Search

Microcrystalline cellulose was dissolved at ambient temperature in 85% H3PO4, and KIO3 was added together with KI to the solution thereby obtained. After 24 h, a white product was isolated by adding cold ethanol. The product has a large specific weight and a high content of iodine. On the basis of IR and NMR spectroscopy data, it is suggested that

Mario Pagliaro

1999-01-01

379

Preparation of activated carbon from cattail and its application for dyes removal  

Microsoft Academic Search

Activated carbon was prepared from cattail by H3PO4 activation. The effects influencing the surface area of the resulting activated carbon followed the sequence of activated temperature > activated time > impregnation ratio > impregnation time. The optimum condition was found at an impregnation ratio of 2.5, an impregnation time of 9 hr, an activated temperature of 500°C, and an activated

Qianqian Shi; Jian Zhang; Chenglu Zhang; Cong Li; Bo Zhang; Weiwei Hu; Jingtao Xu; Ran Zhao

2010-01-01

380

New effects in the kinetics of the electrochemical oxidation of silicon  

Microsoft Academic Search

The present work describes new effects in the kinetics of the electrochemical oxidation of silicon observed recently by the author. One is the observation of very large oscillations of anodic potential during anodization of silicon in H3PO4\\/HF electrolyte and another is the effect of externally applied mechanical stress onto the kinetics of the Si anodization in concentrated and diluted HF.

Vitali Parkhutik

2000-01-01

381

Electron impact cross sections for surrogates of DNA sugar phosphate backbone  

NASA Astrophysics Data System (ADS)

Ionization and elastic cross sections by electron impact on H3PO4 and OP(OCH3)3 which are substitutes for the components of DNA phosphate group. We have employed the Complex Scattering Potential-ionization contribution (CSP-ic) formalism to calculate the cross sections in the energy range from ionization threshold to 2000 eV.

Bhowmik, Pooja; Joshipura, K. N.; Pandya, Siddharth

2012-11-01

382

Enhanced xylose recovery from oil palm empty fruit bunch by efficient acid hydrolysis.  

PubMed

Oil palm empty fruit bunch (EFB) is abundantly available in Malaysia and it is a potential source of xylose for the production of high-value added products. This study aimed to optimize the hydrolysis of EFB using dilute sulfuric acid (H2SO4) and phosphoric acid (H3PO4) via response surface methodology for maximum xylose recovery. Hydrolysis was carried out in an autoclave. An optimum xylose yield of 91.2 % was obtained at 116 °C using 2.0 % (v/v) H2SO4, a solid/liquid ratio of 1:5 and a hydrolysis time of 20 min. A lower optimum xylose yield of 24.0 % was observed for dilute H3PO4 hydrolysis at 116 °C using 2.4 % (v/v) H3PO4, a solid/liquid ratio of 1:5 and a hydrolysis time of 20 min. The optimized hydrolysis conditions suggested that EFB hydrolysis by H2SO4 resulted in a higher xylose yield at a lower acid concentration as compared to H3PO4. PMID:23709290

Tan, Hooi Teng; Dykes, Gary A; Wu, Ta Yeong; Siow, Lee Fong

2013-05-26

383

Deuterium and Solvent Effects on Benzaldehyde Phosphorescence.  

National Technical Information Service (NTIS)

The phosphorescence lifetime and spectra of benzaldehyde, benzaldehyde-d1 and benzaldehyde-d6 have been measured in methylcyclohexane, EPA, and 85% H3PO4 glasses at 77K. The measurements are consistent with a triplet state assignement of triplet n, pi* in...

J. Simpson H. Offen

1970-01-01

384

Influence of flue gas cleaning system on the energetic efficiency and on the economic performance of a WTE plant  

Microsoft Academic Search

Gas cleaning systems of MSW (Municipal Solid Waste) incinerators are characterised by the process employed to remove acid gases. The commonly used technologies for acid gas removal are: (1) dry treatment with Ca(OH)2 or (2) with NaHCO3, (3) semi-dry process with Ca(OH)2 and (4) wet scrubbing. In some recent plants beside a wet cleaning system, a dry neutralization with Ca(OH)2

A. Poggio; E. Grieco

2010-01-01

385

Dechlorination of auto shredder residues  

Microsoft Academic Search

Dechlorination of ASR (auto shredder residual) wastes has been studied in the present work. ASR was predechlorinated with Ca(OH)2 extraction as well as dechlorinated with Ca(OH)2 during incineration or pyrolysis. Experimentally, pre-dechlorination of ASR via extraction of Cl with a Ca(OH)2 solution (pH 12.5) may reduce Cl contain in the ASR by 15%. Extraction of Cl at elevated temperatures (such

Hua-Shan Tai; Chia-Ming Liu; Yun-Jou Wu

2007-01-01

386

Removal of Inorganic Contaminants From Simulated Stormwater by Three Sorbents in Columns Under Intermittent Runoff Condition  

Microsoft Academic Search

Combined removal of inorganic contaminants from a synthetic stormwater was investigated by their sorption on hydrous ferric oxide (HFO) (5%), HFO +Ca(OH)2(6%), and HFO +Ca(OH)2+MnO2 (7%) in columns containing 93-95% anthracite, conducted under seven intermittent runoffs, each of 8 h duration with a 40 h (drying) period between them. At the initial period when Ca(OH)2 produced elevated pHs, the HFO column removed

T. Mohammed; S. Vigneswaran; P. Loganathan; J. Kandasamy; R. Aryal

2012-01-01

387

Influence of calcium hydroxide dressing and acid etching on the push-out bond strengths of three luting resins to root canal dentin.  

PubMed

OBJECTIVES: This study aims to investigate the effects of calcium hydroxide (Ca(OH)2) dressing in root canals and the effects of subsequent acid etching on the adhesion of luting resins to root canals. MATERIALS AND METHODS: Root specimens were prepared from extracted human permanent molars. Specimen canals were (1) filled with etch-and-rinse (Nexus® third generation (NX3)) and two self-adhesive (RelyX Unicem, Maxcem Elite) luting resins, respectively; (2) dressed with Ca(OH)2 before Ca(OH)2 removal and luting resin filling; (3) dressed with Ca(OH)2 before Ca(OH)2 removal and post-cementation; or (4) treated as described in item (2) except that the canals were further etched with phosphoric acid before luting resin filling. Push-out bond strengths were measured and analyzed using one-way analysis of variance, and Fisher's multiple comparison tests provided a follow-up comparison among these four canal treatments. Attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were used to analyze the specimen surfaces. RESULTS: Ca(OH)2 dressing adversely affected the bond strengths to canal dentin of the three luting resins tested. Acid etching did not increase the bond strengths. Infrared analysis revealed that Ca(OH)2 dressing caused no structural changes on the dentin surface. XPS and SEM analyses revealed Ca(OH)2 remnants as the ultimate chemical cause leading to the decrease in bond strength. CONCLUSIONS: The bond strength of luting resin to dentin was affected by Ca(OH)2 dressing. Acid etching treatment could not increase the bond strength. CLINICAL RELEVANCE: Adhesion of the fiber post to the root canal wall may be compromised after Ca(OH)2 dressing. An effective method for complete removal of Ca(OH)2 dressing or increase of bond strength for luting resin needs to be developed. PMID:23686133

Lee, Bor-Shiunn; Lin, Yu-Chen; Chen, Sing-Fu; Chen, Shu-Yu; Chang, Che-Chen

2013-05-18

388

The dissociation of phosphoric acid in NaCl and NaMgCl solutions at 25°C  

Microsoft Academic Search

The pK1*, pK1* and pK3* for the dissociation of H3PO4 have been measured in NaCl solutions from 0.5 to 6m at 25°C. The results have been used to evaluate Pitzer interaction parameters ?(NaClH2PO4)=-0.028±0.005, ?(NaH3PO4)=-0.075±0.025, ?(HPO4Cl)=0.105±0.009, ?(PO4Cl)=-0.59±0.02 and ?(NaClHPO4)=-0.003±0.004, ?(PO4NaClH)=0.110±0.008. These parameters yield values of pK1*, pK2* and pK3* in NaCl that agree with the measured values with average deviations of

J. Peter Hershey; Marino Fernandez; Frank J. Millero

1989-01-01

389

Influence of the experimental conditions on porosity and structure of adsorbents elaborated from Moroccan oil shale of Timahdit by chemical activation.  

PubMed

This study records experiments undertaken to determine the suitable conditions for the use of the oil shale of Timahdit, as an adsorbent for water treatment. A simple process was proposed based on chemical activation. The preparation has been carried out by carbonization after impregnation of the precursor with phosphoric acid. The effect of different conditions of preparation on the specific surface area is discussed. These parameters are H3PO4/shale weight ratio, carbonization temperature, carbonization time and concentration of H3PO4. The properties and surface structure of the adsorbent were investigated by XPS and FT-IR. Their total surface acidity and basicity were also determined. The retention process of methylene blue (MB) by adsorbents has been studied. It was found that MHP2 and MHP7 have relatively high retention ability as compared to activated carbons. PMID:15721527

Ichcho, S; Khouya, E; Fakhi, S; Ezzine, M; Hannache, H; Pallier, R; Naslain, R

2005-02-14

390

Variation of nanopore diameter along porous anodic alumina channels by multi-step anodization.  

PubMed

In order to form tapered nanocapillaries, we investigated a method to vary the nanopore diameter along the porous anodic alumina (PAA) channels using multi-step anodization. By anodizing the aluminum in either single acid (H3PO4) or multi-acid (H2SO4, oxalic acid and H3PO4) with increasing or decreasing voltage, the diameter of the nanopore along the PAA channel can be varied systematically corresponding to the applied voltages. The pore size along the channel can be enlarged or shrunken in the range of 20 nm to 200 nm. Structural engineering of the template along the film growth direction can be achieved by deliberately designing a suitable voltage and electrolyte together with anodization time. PMID:21456152

Lee, Kwang Hong; Lim, Xin Yuan; Wai, Kah Wing; Romanato, Filippo; Wong, Chee Cheong

2011-02-01

391

Flame retardancy of polyaniline-deposited paper composites prepared via in situ polymerization.  

PubMed

Polyaniline-deposited paper composites doped with three inorganic acids were prepared via in situ polymerization, and their flame-retardant properties were investigated. Both the conductivity and flame retardancy of the composite increased with the increase of the amount of the polyaniline deposited. The doping acid played a very key role in both the conductivity and flame retardancy of the composite. The comprehensive properties of the composite could be improved when codoped with an equimolar mixture of H(3)PO(4) and H(2)SO(4) or H(3)PO(4) and HCl. The decay of the flame retardancy of the composite in atmosphere was due to the dedoping of the polyaniline deposited on cellulose fibers. PMID:23218317

Wu, Xianna; Qian, Xueren; An, Xianhui

2012-09-24

392

Effect of preparation conditions of activated carbon from bamboo waste for real textile wastewater.  

PubMed

This study deals with the use of activated carbon prepared from bamboo waste (BMAC), as an adsorbent for the removal of chemical oxygen demand (COD) and color of cotton textile mill wastewater. Bamboo waste was used to prepare activated carbon by chemical activation using phosphoric acid (H(3)PO(4)) as chemical agent. The effects of three preparation variables activation temperature, activation time and H(3)PO(4):precursor (wt%) impregnation ratio on the color and COD removal were investigated. Based on the central composite design (CCD) and quadratic models were developed to correlate the preparation variables to the color and COD. From the analysis of variance (ANOVA), the most influential factor on each experimental design response was identified. The optimum condition was obtained by using temperature of 556 degrees C, activation time of 2.33 h and chemical impregnation ratio of 5.24, which resulted in 93.08% of color and 73.98% of COD. PMID:19765899

Ahmad, A A; Hameed, B H

2009-08-31

393

EFFECT OF LASER LIGHT ON MATTER. LASER PLASMAS: Effects of CO2 laser radiation on large orthophosphoric acid and water drops and on spherical ice crystals  

NASA Astrophysics Data System (ADS)

An experimental investigation is reported of the conditions present during evaporation of suspended orthophosphoric acid and water drops, and of spherical ice crystals with a radius of the order of 1 mm when the laser radiation power density was 20-104 W cm-2 at the wavelength of 10.6 ?m. The lower limit of explosive evaporation was determined for H3PO4 drops and ice crystals. Only one evaporation mechanism of H3PO4 drops was observed (this mechanism was explosive), but there were two mechanisms in the case of water drops (convective with vapour ejection and explosive) and spherical ice crystals (melting followed by evaporation of a water drop and explosive evaporation). Repeated explosions of H2O drops were observed for a power density w = 104 W cm-2 when the beam diameter was 10 mm.

Rudash, V. K.

1994-02-01

394

Thermodynamic Study of Corrosion and Inhibitor Adsorption Processes onto C38 Steel/piperazines/phosphoric Acid Systems  

NASA Astrophysics Data System (ADS)

This paper describes the inhibition effect of 1-benzyl piperazine (P1) and bis(1-benzyl piperazine) thiuram disulfide (P2) towards the corrosion of C38 steel in 5.5 M H3PO4 solution by potentiodynamic polarization and weight loss methods. The influence of inhibitor concentration and temperature on inhibitory behavior of P2 were investigated. The inhibition efficiency (IE) was found to be dependent on the type of piperazine and its concentration. The IE for 10-3 M P2 in 5.5 M H3PO4 is greater than 98%. Polarization studies clearly revealed that both P1 and P2 act as mixed-type inhibitors. Adsorption isotherms were fitted by the Langmuir isotherm. Adsorption energies (? Go{ ads} and ? Ho{ ads}) were evaluated. Kinetic parameters were determined.

Ousslim, A.; Ouniti, A.; Bekkouch, K.; Elidrissi, A.; Hammouti, B.

395

LiFePO 4 doped with magnesium prepared by hydrothermal reaction in glucose solution  

Microsoft Academic Search

Lithium iron phosphate (LiFePO4) doped with magnesium was hydrothermally synthesized from commercial LiOH, FeSO4, H3PO4 and MgSO4 with glucose as carbon precursor in aqueous solution. The samples were characterized by X-ray powder diffraction, scanning electron microscopy and constant charge–discharge cycling. The results show that the synthesized powders have been in situ coated with carbon precursor produced from caramel reaction of

Xiu Qin Ou; Guang Chuan Liang; Jin Sheng Liang; Sheng Zhao Xu; Xia Zhao

2008-01-01

396

Licorice residue and Pistachio-nut shell mixture: A promising precursor for activated carbon  

Microsoft Academic Search

As a continuation of previous research concerning preparation of activated carbon from agricultural by-products, applying a mixture of two kinds of lignocellulosic by-products with complementary properties as the parent material is investigated. Two kinds of activated carbons are prepared by chemical activation of the parent mixture – including residues of licorice and pistachio-nut shells – with H3PO4 and ZnCl2 solutions,

T. Kaghazchi; N. Asasian Kolur; M. Soleimani

2010-01-01

397

Reactions of stereocontrolled intramolecular carbocyclization of levoglucosenone adduct with isoprene  

Microsoft Academic Search

An intramolecular carbocyclization was found of levoglucosenone adduct with isoprene providing a fused cyclobutane. The intramolecular\\u000a oxacyclization of the adduct was performed under the treatment with I2, H3PO4, SOCl2, and Pd\\/C leading to 1,4-epoxide. Methods were developed of radical and anionic (by Ferrier method) transformation of the\\u000a adduct into chiral trans- and cis-decalins.

B. T. Sharipov; O. Yu. Krasnoslobodtseva; L. V. Spirikhin; F. A. Valeev

2010-01-01

398

Liquefaction of corn stover and preparation of polyester from the liquefied polyol  

Microsoft Academic Search

This research investigated a novel process to prepare polyester from corn stover through liquefaction and crosslinking processes.\\u000a First, corn stover was liquefied in organic solvents (90 wt% ethylene glycol and 10 wt% ethylene carbonate) with catalysts\\u000a at moderate temperature under atmospheric pressure. The effect of liquefaction temperature, biomass content, and type of catalyst,\\u000a such H2SO4, HCl, H3PO4, and ZnCl2, was

Fei Yu; Yuhuan Liu; Xuejun Pan; Xiangyang Lin; Chengmei Liu; Paul Chen; Roger Ruan

2006-01-01

399

Determination of Fluoxetine and Norfluoxetine in Plasma by a Modified High Performance Reversed Phase Liquid Chromatographic Method with Fluorescence Detection  

Microsoft Academic Search

A simple and rapid reversed phase liquid chromatographic method for the determination of fluoxetine (F) and norfluoxetine (NF) in plasma has been developed and validated. Protriptyline (P) was used as internal standard. Plasma samples were extracted from alkaline pH with hexane–isoamyl alcohol 98:2 v\\/v on a rotator drive for 10 min. The organic phase was back extracted with H3PO4 0.1 M and the

P. Fraskou; M. Koupparis

2005-01-01

400

Supramolecular interaction of ethylenediamine linked ?-cyclodextrin dimer and berberine hydrochloride by spectrofluorimetry and its analytical application  

Microsoft Academic Search

The supramolecular interaction of ?-cyclodextrin dimer with berberine hydrochloride was studied in aqueous KH2PO4–H3PO4 buffer solution of pH 2.00 at room temperature by spectrofluorimetry. The apparent association constant of the complex was 1.53×104Lmol?1. Based on the significant enhancement of fluorescence intensity of supramolecular sandwich complexes, a spectrofluorimetric method with high sensitivity and selectivity was developed for the determination of berberine

Fang Liu; Hui-ling Liang; Ke-hua Xu; Li-li Tong; Bo Tang

2007-01-01

401

Recovery of volatile aroma components from aqueous waste streams using an activated carbon column  

Microsoft Academic Search

The solid phase adsorption of aroma components depleted from essential oils and drained with the condensed water water during the distillation of aromatic plants onto granular activated carbon (GAC) is reported. A mini-column packed with laboratory-prepared activated carbon, derived from pistachio shells, which were previously treated with H3PO4 and pyrolysed at 500 °C, was used. Three aromatic waste waters (peppermint, lemongrass,

Amr E. Edris; Badie S. Girgis; Hoda H. M. Fadel

2003-01-01

402

The synthesis and physicochemical parameters of new nonionic surfactants based on 1,2-propylene glycol, epichlorohydrin, and orthophosphoric acid  

Microsoft Academic Search

1,2-Propylene glycol has been chloroxypropylated with epichlorohydrin. The structures and compositions of synthesized oligomers\\u000a having different average degrees of chloroxypropylation have been determined by IR and 1H NMR spectroscopy. The physicochemical parameters of the oligomers have been determined, and their surface activity has been\\u000a studied. The same characteristics have been found for 1,2-propylene glycol chloroxypropylates phosphatized with H3PO4. The ability

G. A. Ahmedova

2009-01-01

403

Synergistic effect of I ? ions on the corrosion inhibition of Al in 1.0 M phosphoric acid solutions by purine  

Microsoft Academic Search

The effect of purine, as a safe inhibitor, was investigated by measuring the corrosion of Al in 1.0M deaerated stirred H3PO4 solution at 25°C. Measurements were conducted under various experimental conditions using polarization and impedance measurements, complemented with EDX examinations of the electrode surface. According to these results, purine alone showed a poor inhibition effect. Addition of I? ions enhanced

Mohammed A. Amin; Q. Mohsen; Omar A. Hazzazi

2009-01-01

404

Deposition of gold–titanium and gold–nickel coatings on electropolished 316L stainless steel bipolar plates for proton exchange membrane fuel cells  

Microsoft Academic Search

The effects of electropolishing and coating deposition on electrical resistance and chemical stability were studied for the stainless steel bipolar plates in proton exchange membrane fuel cell (PEMFC). A series of 316L stainless steel plates, selected as the substrate for a proton exchange membrane fuel cell (PEMFC) bipolar plate, were electropolished with a solution of H2SO4 and H3PO4 at temperatures

Young-Hoon Yun

2010-01-01

405

Applicability of Activated Carbon to Treatment of Waste Containing Iodine-Labeled Compounds  

Microsoft Academic Search

A timber industry waste was transformed to activated carbon by a one-step chemical activation process using H3PO4 (H). The used activated carbon (SDH) was characterized by N2 adsorption, FTIR, density, pH, point of zero charge pHpzc, moisture and ash content. Methylene blue (MB) and the iodine number were calculated by adsorption from the solution. The applicability of the different activated

H. M. H. Gad; N. R. A. El-Mouhty; H. F. Aly

2009-01-01

406

Effect of PPTA preimpregnation with phosphoric acid on the porous texture of carbons prepared by CO 2 activation of PPTA chars  

Microsoft Academic Search

Activated carbon fibers (ACFs) were prepared by CO2 gasification to different burn-offs of chars from the polyaramid fiber, poly(p-phenylene terephthalamide) (PPTA) pre-impregnated with 5wt.% H3PO4. Thermogravimetric analysis showed that the addition of phosphoric acid produces a significant increase in the yield of solid residue. While the char yield of the pure polymer at 1000°C amounted to 39.5wt.%, it rose to

Alberto Castro-Muñiz; Amelia Martínez-Alonso; Juan M. D. Tascón

2009-01-01

407

Preparation of activated carbon from bituminous coal with phosphoric acid activation  

Microsoft Academic Search

Activated carbons were prepared from an Australian bituminous coal in this study. The preparation process consisted of phosphoric acid impregnation followed by carbonization in nitrogen at 400–600°C for 1–3hours. The results reveal that the surface area and pore volume of the resulting carbons increase with the chemical ratio, H3PO4\\/coal. Within the ranges of carbonization temperature and time, the chemically activated

Hsisheng Teng; Tien-Sheng Yeh; Li-Yeh Hsu

1998-01-01

408

The effect of phosphoric acid concentration on resin tag length and bond strength of a photo-cured resin to acid-etched enamel  

Microsoft Academic Search

Objectives: To determine the relationship between depth of penetration and tensile bond strength of a photo-cured resin to phosphoric acid etched enamel, and the efficacy of enamel etchants that are less aggressive than a concentration of 10% H3PO4.Methods: The tensile bond strength and length of tags produced by a photo-cured (20s) resin consisting of pre-polymerized TMPT\\/silica in 3% HNPM–TEGDMA on

M. J. Shinchi; K. Soma; N. Nakabayashi

2000-01-01

409

Study of the hydrolysis of sugar cane bagasse using phosphoric acid  

Microsoft Academic Search

In the present work, samples of sugar cane bagasse were hydrolysed with phosphoric acid under mild conditions (H3PO4 2–6%, time 0–300min and 122°C) to study the feasibility of using the liquid phase as fermentation media. Solid yield, sugar concentrations and decomposition product concentrations were measured. The composition of hydrolysates, their purity and the ratio sugars\\/inhibitors were analyzed. Kinetic models were

Sara Gámez; Juan Jose González-Cabriales; José Alberto Ramírez; Gil Garrote; Manuel Vázquez

2006-01-01

410

Effect of phosphoric acid concentration on wet-bonding to etched dentin  

Microsoft Academic Search

Objective. This study was conducted to investigate the influence of phosphoric acid (H3PO4) demineralization of dentin during smear layer removal prior to dentin bonding.Methods. Bovine dentin was pre-treated with either 10 wt% or 35 wt% phosphoric acid for 30 s. Substrates were then rinsed and either kept moist or air-dried before a light-cured bonding system was applied. The adhesive system

Gen Kato; Nobuo Nakabayashi

1996-01-01

411

Corrosion of zirconia ceramics in acidic solutions at high pressures and temperatures  

Microsoft Academic Search

Changes in microstructure and phase composition of ceria stabilized tetragonal zirconia polycrystals (Ce-TZP), magnesia and yttria partially stabilized zirconia [(Mg,Y)-PSZ] and magnesia partially stabilized zirconia (Mg-PSZ) were studied in diluted aqueous HCl, H2SO4 or H3PO4 solutions at a temperature of 390°C and a pressure of 27MPa. Ce-TZP is corrosion resistant under these conditions in HCl, while Mg-PSZ is attacked severely

Michael Schacht; Nikolaos Boukis; Eckhard Dinjus; Klaus Ebert; Rolf Janssen; Frank Meschke; Nils Claussen

1998-01-01

412

Effect of Level of Acidification by Phosphoric Acid, Storage Temperature, and Length of Storage on the Chemical and Biological Stability of Ground Poultry Mortality Carcasses1  

Microsoft Academic Search

Two experiments were conducted to eval- uate the addition of feed-grade H3PO4 in comparison to lactic acid fermentation as a means of preserving ground poultry mortality carcasses. Mortality silage quality in both experiments was evaluated by measuring the rise in pH after initial acidification (?pH) and the content of nonprotein N (NPN), volatile nitrogen (VN), NH3-N, and fecal coliform bacteria

T. F. Middleton; P. R. Ferket

413

Effect of Strong Acids on Mechanical Properties of Glass\\/Polyester GRP Pipe at Normal and High Temperatures  

Microsoft Academic Search

The effects of hydrochloric acids (HCl), sulfuric acids (H2SO4), nitric acids (HNO3), and phosphoric acids (H3PO4) on the physical and mechanical properties of glass fiber\\/polyester composite pipes internally lined with C glass were investigated. Specimens cut from the pipes were immersed for various periods—30, 60, and 90 days in 20% acid concentration at room temperature and 100°C. The pipes consisted

Mahmoud K. Mahmoud; S. H. Tantawi

2003-01-01

414

Effect of activation method on the pore structure of activated carbon from date pits application to the treatment of water  

Microsoft Academic Search

Four active carbons have been prepared by carbonisation without adjuvant (DC) and by chemical activation of date pits with ZnCl2 (DZ), KOH (DK), and H3PO4 (DP) in order to show the effect of variables such as the nature of the chemical reagent, extent of impregnation on the adsorbent surface area, and porosity of the resulting activated carbons. The pore structure

Zoulikha Merzougui; Yacine Azoudj; Naima Bouchemel; Fatima Addoun

2011-01-01

415

Activated Carbon Production from Date Stones Using Phosphoric Acid  

Microsoft Academic Search

The effects of activation time and activation temperature on the yield and the adsorptive capacity towards iodine were studied. The yield and the quality of the activated carbon prepared by using H3PO4 were compared with that prepared from date stones using the same equipment, and under similar conditions by using ZnCl2 as an oxidizing agent. The iodine number for the

F. Al-Qaessi; L. Abu-Farah

2010-01-01

416

Porosity development in activated carbons obtained from date pits under chemical activation with phosphoric acid  

Microsoft Academic Search

Date pits, a low-cost agricultural by-product, was tested as a precursor for the production of porous carbons in a chemical scheme using phosphoric acid. The raw material was impregnated with increasing concentrations of H3PO4 (30–70 vol.%) followed by pyrolysis at 300, 500 or 700 °C. Texture characteristics of the products were determined by adsorption of N2 at 77 K, as

Badie S. Girgis; Abdel-Nasser A. El-Hendawy

2002-01-01

417

The effect of temperature and impregnation ratio on the active carbon porosity  

Microsoft Academic Search

Three active carbons were prepared starting from Algerian date pits by chemical activation with the H3PO4, ZnCl2 and by the method combined in the presence of ZnCl2\\/CO2. A systematic study of certain parameters (temperature of activation and impregnation ratio) was undertaken. The active carbons obtained were followed by the evaluation of the yield and the physisorption of nitrogen at 77

Naïma Bouchemal; Meriem Belhachemi; Zoulikha Merzougui; Fatima Addoun

2009-01-01

418

Chemical Extraction of Arsenic from Contaminated Soil  

Microsoft Academic Search

A series of batch extraction experiments were conducted using a fortified soil with different extracting solutions such as inorganic acids (hydrochloric acid (HCl), sulfuric acid (H2SO4), phosphoric acid (H3PO4), perchloric acid (HClO4), or nitric acid (HNO3)), organic acids (acetic acid (C2H4O2), citric acid (C6H8O7)) and alkaline agent (NaOH). Various concentrations were used to investigate the removal efficiency and to optimise

M. G. M. ALAM; S. TOKUNAGA

2006-01-01

419

The solubility of ozone in aqueous solutions of sulfuric, phosphoric, and perchloric acids  

Microsoft Academic Search

The solubility of ozone in pure water and aqueous solutions of sulfuric, phosphoric, and perchloric acids was determined at\\u000a 20°C. An increase in the concentration of H3PO4 and HClO4 (to 14.8 and 9.5 M, respectively) caused a monotonic decrease in the solubility of ozone. The solubility of ozone in sulfuric\\u000a acid was minimum at a 12 M concentration; the solubility

A. V. Levanov; I. V. Kuskov; E. E. Antipenko; V. V. Lunin

2008-01-01

420

The use of catalytic hydrogenation to intercept carbohydrates in a dilute acid hydrolysis of biomass to effect a clean separation from lignin  

Microsoft Academic Search

Biomass carbohydrates are fractionated very cleanly (>99%) from unreacted insoluble lignin by a dilute acid hydrolysis (0.35–1.5% H3PO4), wherein the incipient aldoses are intercepted by catalytic hydrogenation (Ru\\/C) to produce a solution of C5–C6 polyols (xylitol, sorbitol) and anhydro polyols (sorbitan) in which no phenols could be detected (<100ppm). A screen removes granular catalyst and lignin is simply filtered from

J. Michael Robinson; Caroline E. Burgess; Melissa A. Bently; Chris D. Brasher; Bruce O. Horne; Danny M. Lillard; José M. Macias; Hari D. Mandal; Samuel C. Mills; Kevin D. O'Hara; Justin T. Pon; Annette F. Raigoza; Ernesto H. Sanchez; José S. Villarreal

2004-01-01

421

Kinetic catalytic determination of trace levels of iodide based on the oxidation of basic dyes with hydrogen peroxide monitored potentiometrically using simple PVC electrodes  

Microsoft Academic Search

Four sensitive catalytic potentiometric methods have been developed for trace levels determination of iodide based on its catalytic effects on the oxidation of four dyes: viz. variamine blue (VB), rhodamine B (RB), methylene blue (MB) and malachite green (MG), with H2O2 in H3PO4 medium at 25±0.5°C. The catalyzed reaction rates were estimated potentiometrically by monitoring the potential of the corresponding

Elmorsy Khaled; M. A. El-Ries; F. I. Zidane; S. A. Ibrahim; M. S. Abd-Elmonem

2011-01-01

422

Interaction of UO 2 2+ with Sodium Dodecyl Sulfate Micelles: Association of Phenols to Micelles through Fluorescence Quenching Data  

Microsoft Academic Search

Time-resolved laser-induced fluorescence (TRLIF) has been used to study the interaction of uranyl ion with sodium dodecyl sulfate (SDS) micelles in H3PO4 1 M. The titration curve consists of two curved regions with different slopes, one of them more pronounced at low concentration of SDS and the other, with a less pronounced positive slope at larger [SDS] until a plateau

Walter A Massad; Patricia Repossi; Gerardo A Argüello

2002-01-01

423

A machine for simultaneous electrolytical polishing and flattening with rotating cathode  

Microsoft Academic Search

A device with horizontal rotating cathode for electrolytical polishing of copper samples is described. This machine allows a thin layer of electrolyte (H3PO4, 50%) whose thickness is adjustable between 0·1 and 0·2 mm to be maintained on the cathode. The anodical sample is immersed into this layer. On account of the small distance between the cathode and anode the sample

H. Fehmer; W. Uelhoff

1969-01-01

424

Variation in the FTIR spectra of a biomass under impregnation, carbonization and oxidation conditions  

Microsoft Academic Search

The FTIR spectra of untreated date pits (DP) and their H3PO4-preimpregnated sample together with their chars as well as samples subjected to different activation schemes were determined. These activated carbons were prepared using phosphoric acid, steam one and two steps and potassium hydroxide. This series of activated carbons were oxidized with HNO3 and their surface modifications were detected by using

Abdel-Nasser A. El-Hendawy

2006-01-01

425

Effect of sulfuric and phosphoric acid pretreatments on enzymatic hydrolysis of corn stover  

Microsoft Academic Search

The pretreatment of corn stover with H2SO4 and H3PO4 was investigated. Pretreatments were carried out from 30 to 120 min in a batch reactor at 121°C, with acid concentrations\\u000a ranging from 0 to 2% (w\\/v) at a solid concentration of 5% (w\\/v). Pretreated corn stover was washed with distilled water until\\u000a the filtrate was adjusted to pH 7.0, followed by

Byung-Hwan Um; M. Nazmul Karim; Linda L. Henk

2003-01-01

426

Interactive effects of salinity and phosphorus nutrition on tepary and common bean cultivars  

Microsoft Academic Search

Increasing plant phosphorus (P) supply has been shown to either increase or decrease the salt tolerance of many crops. A hydroponic culture experiment was conducted in the greenhouse using aerated Hoagland nutrient solution to examine interactive effects of salinity (10, 50, and 100 mM of NaCl) and P (1, 10, and 100 ?M of H3PO4) on shoot and root growth,

H. Z. Zaiter; M. Saade

1993-01-01

427

Porous polyaniline films with high conductivity  

Microsoft Academic Search

Porous polyaniline (PANI) films with high conductivity at room temperature have been prepared by a new method called ‘doping-dedoping-redoping’. The room-temperature conductivity of the resulting PANI films doped with HCl, HClO4, H2SO4, H3PO4 and p-toluene sulfonic acid (p-TSA), can reach 200–300 S cm?1, which is comparable with the results of PANI films doped with camphor sulfonic acid (CSA) in m-cresol.

Wenguang Li; Meixiang Wan

1998-01-01

428

Mechanistic Investigation of Phosphate Ester Bond Cleavages of Glycylphosphoserinyltryptophan Radical Cations under Low-Energy Collision-Induced Dissociation  

NASA Astrophysics Data System (ADS)

Under the conditions of low-energy collision-induced dissociation (CID), the canonical glycylphosphoserinyltryptophan radical cation having its radical located on the side chain of the tryptophan residue ([G p SW]•+) fragments differently from its tautomer with the radical initially generated on the ?-carbon atom of the glycine residue ([G• p SW]+). The dissociation of [G• p SW]+ is dominated by the neutral loss of H3PO4 (98 Da), with backbone cleavage forming the [b2 - H]•+/y1 + pair as the minor products. In contrast, for [G p SW]•+, competitive cleavages along the peptide backbone, such as the formation of [G p SW - CO2]•+ and the [c2 + 2H]+/[z1 - H]•+ pair, significantly suppress the loss of neutral H3PO4. In this study, we used density functional theory (DFT) to examine the mechanisms for the tautomerizations of [G• p SW]+ and [G p SW]•+ and their dissociation pathways. Our results suggest that the dissociation reactions of these two peptide radical cations are more efficient than their tautomerizations, as supported by Rice-Ramsperger-Kassel-Marcus (RRKM) modeling. We also propose that the loss of H3PO4 from both of these two radical cationic tautomers is preferentially charge-driven, similar to the analogous dissociations of even-electron protonated peptides. The distonic radical cationic character of [G• p SW]+ results in its charge being more mobile, thereby favoring charge-driven loss of H3PO4; in contrast, radical-driven pathways are more competitive during the CID of [G p SW]•+.

Quan, Quan; Hao, Qiang; Song, Tao; Siu, Chi-Kit; Chu, Ivan K.

2013-04-01

429

Effect of interface chloride ion perturbation on oscillatory electrodissolution  

Microsoft Academic Search

This paper investigated the effect of chloride ion perturbation on the electrodissolution behavior of carbon steel in 5.0M H3PO4 solution. The results indicated that the oscillatory electrodissolution changes significantly when the electrode\\/electrolyte interface was disturbed by injecting small quality of chloride ion-containing solution. The mode of current oscillations changed from the mono-periodic to the nonperiodic behavior with higher frequencies but

L. Li; J. L. Luo; B. T. Lu; S. H. Chen

2005-01-01

430

Chemical synthesis of bone-like carbonate hydroxyapatite from hen eggshells and its characterization  

Microsoft Academic Search

Carbonate hydroxyapatite (CHAp) was synthesized from domestic hen eggshells by using three alternative wet chemical methods at room temperature. In the first method, the powdered eggshells were reacted directly with H 3PO4. In the other two methods, calcium acetate was obtained in a first step by dissolving the eggshells in acetic acid. Then, calcium acetate was reacted with Na3PO4·12H2O and

J. L. ACEVEDO-DÁVILA; J. MÉNDEZ-NONELL

431

Structure and antibacterial activity of silver-supporting activated carbon fibers  

Microsoft Academic Search

In this paper, several kinds of silver supporting activated carbon fibers (ACF-Ag) were prepared by the reduction adsorption\\u000a on activated carbon fiber (ACF) activated with steam or H3PO4 using sisal, viscose and pitch fiber as precursors. Their pore structure and surface chemistry were characterized using nitrogen\\u000a adsorption, XPS, WXRD and ICP quantitative analysis. Their antibacterial activities were tested. The results

Shuixia Chen; Jinrong Liu; Hanmin Zeng

2005-01-01

432

Proximal direct composite restorations and chairside CAD\\/CAM inlays: Marginal adaptation of a two-step self-etch adhesive with and without selective enamel conditioning  

Microsoft Academic Search

The aim of this study was to evaluate the marginal adaptation of CEREC ceramic inlays, CEREC composite inlays and direct composite\\u000a restorations in unbeveled proximal slot cavities under artificial aging conditions. Two groups of each restoration type were\\u000a prepared (n?=?6), one group with a self-etch adhesive, the other group with H3PO4 enamel etching before the self-etch adhesive application. Replicas were

T. Bortolotto; I. Onisor; I. Krejci

2007-01-01

433

Beneficial effects of phosphoric acid as an additive in the preparation of activated carbon fibers from Nomex aramid fibers by physical activation  

Microsoft Academic Search

Activated carbon fibers (ACFs) were prepared by CO2 activation of chars obtained by pyrolyzing Nomex [poly (m-phenylene isophthalamide)], either alone or pre-impregnated with phosphoric acid (impregnation ratio of 7 wt.% H3PO4). The resulting materials were characterized by elemental analysis, X-ray diffraction, SEM-EDX, thermogravimetry and N2 (77 K) and CO2 (273 K) adsorption. Nomex impregnation with phosphoric acid produced an increase

F Suárez-Garc??a; A Mart??nez-Alonso; J. M. D Tascón

2002-01-01

434

Advancing the manufacturing process of zirconia vessels for installations for nickel evaporation  

Microsoft Academic Search

The effect of activating additives of H3PO4 and zirconium oxychloride and a sintering additive of A12O3 on the properties of zirconia concrete mixtures containing colloidal suspensions and vibroshaped articles on their base is\\u000a described. The optimum amounts of the additives and the principal physicomechanical properties of the articles are determined.\\u000a The effect of the heat treatment temperature of zirconia vibroshaped

A. G. Karaulov; N. M. Chudnova; N. V. Pashchenko

1998-01-01

435

Amphibious hybrid nanostructured proton exchange membranes  

Microsoft Academic Search

Amphibious proton exchange membranes (PEMs) which could be used under both wet and dry conditions were prepared by sol–gel method in this work. Those novel hybrid PEMs were constructed by three parts: (1) polysiloxane with two basic sites (–NH– on the pendant and N– in the triazole); (2) H3PO4 as the proton source; (3) poly(vinyl alcohol) (PVA) which had good

Songjun Zeng; Lei Ye; Sijia Yan; Guoliang Wu; Yuanqin Xiong; Weijian Xu

2011-01-01

436

Rapid Methods of Staining Bacterial Spores at Room Temperature  

PubMed Central

Lechtman, M. D. (University of Southern California, Los Angeles), J. W. Bartholomew, A. Phillips, and M. Russo. Rapid methods of staining bacterial spores at room temperature. J. Bacteriol. 89:848–854. 1965.—Spores of Bacillus subtilis var. niger were stained in 2 min at room temperature, after suitable pretreatment, with a dye reagent composed of 2% crystal violet in 1% phenol and 26% ethanol. Pretreatments included heat fixation to 260 C, mechanical rupture, and hydrolysis at room temperature in 44 n H3PO4 for 5 min, 33.4 n H3PO4 for 10 min, 12 n HCl for 5 sec, 6 n HCl for 2 min, 12 n HNO3 for 5 sec, and 6 n HNO3 for 60 sec. Acid hydrolysis at 60 C enabled the lowering of both acid concentration and time: 33.4 n H3PO4 for 15 sec, 25.9 n H3PO4 for 60 sec, 2 n HCl for 30 sec, 1 n HCl for 30 sec, 2 n HNO3 for 15 sec, and 1 n HNO3 for 30 sec. After acid treatment, 1 n NaOH was used as a neutralization agent. The cytological manifestations of these pretreatments, examined in an electron microscope after replication, showed definite degradation of spore coats, which probably explains the increase in dye permeability. The pretreatments were evaluated for use in a differential staining procedure for spores and vegetative cells. They were found to be too drastic in that they resulted in replacement of the primary dye by the 0.25% safranine counter stain in both vegetative cells and endospores. Less drastic pretreatments, such as 6 n HNO3 for 10 sec at room temperature, gave good differential stains, but failed to stain some free spores. The staining techniques above were evaluated with six species of Bacillus and were found to apply to all. Images

Lechtman, M. D.; Bartholomew, J. W.; Phillips, A.; Russo, M.

1965-01-01

437

Preliminary surface analysis of etched, bleached, and normal bovine enamel  

SciTech Connect

X-ray photoelectron spectroscopic (XPS) and secondary ion-mass spectroscopic (SIMS) analyses were performed on unground un-pumiced, unground pumiced, and ground labial enamel surfaces of young bovine incisors exposed to four different treatments: (1) immersion in 35% H2O2 for 60 min; (2) immersion in 37% H3PO4 for 60 s; (3) immersion in 35% H2O2 for 60 min, in distilled water for two min, and in 37% H3PO4 for 60 s; (4) immersion in 37% H3PO4 for 60 s, in distilled water for two min, and in 35% H2O2 for 60 min. Untreated unground un-pumiced, unground pumiced, and ground enamel surfaces, as well as synthetic hydroxyapatite surfaces, served as controls for intra-tooth evaluations of the effects of different treatments. The analyses indicated that exposure to 35% H2O2 alone, besides increasing the nitrogen content, produced no other significant change in the elemental composition of any of the enamel surfaces investigated. Exposure to 37% H3PO4, however, produced a marked decrease in calcium (Ca) and phosphorus (P) concentrations and an increase in carbon (C) and nitrogen (N) concentrations in unground un-pumiced specimens only, and a decrease in C concentration in ground specimens. These results suggest that the reported decrease in the adhesive bond strength of resin to 35% H2O2-treated enamel is not caused by a change in the elemental composition of treated enamel surfaces. They also suggest that an organic-rich layer, unaffected by acid-etching, may be present on the unground un-pumiced surface of young bovine incisors. This layer can be removed by thorough pumicing or by grinding. An awareness of its presence is important when young bovine teeth are used in a model system for evaluation of resin adhesiveness.

Ruse, N.D.; Smith, D.C.; Torneck, C.D.; Titley, K.C. (Univ. of Toronto, Ontario (Canada))

1990-09-01

438

The Use of Activated Carbon Prepared from Jackfruit (Artocarpus heterophyllus) Peel Waste for Methylene Blue Removal  

Microsoft Academic Search

Jackfruit peel waste which has no economic value has been utilized for activated carbon preparation. The preparation of the activated carbon was carried out using chemical activation with phosphoric acid as activating agent. The impregnation ratio was 4:1 (g H3PO4\\/g raw material) and semi carbonization process was conducted at 200oC and followed with carbonization at 550oC. The applicability of this

Devarly PRAHAS; Yoga KARTIKA; Nani INDRASWATI; Suryadi ISMADJI

439

Corrosion inhibition of aluminum 6063 using some pharmaceutical compounds  

Microsoft Academic Search

The corrosion inhibition characteristics of some pharmaceutical compounds on aluminium 6063 in 0.5 mol l?1 H3PO4 has been studied using weight loss and galvanostatic polarization techniques. Results showed that the inhibition occurs through\\u000a adsorption of the inhibitor molecules on the metal surface. The inhibition efficiency increased with increasing inhibitor\\u000a concentration, but decreased with increasing temperature. The adsorption of first group

A. S. Fouda; A. A. Al-Sarawy; F. Sh. Ahmed; H. M. El-Abbasy

2009-01-01

440

Corrosion inhibition of aluminum 6063 using some pharmaceutical compounds  

Microsoft Academic Search

The corrosion inhibition characteristics of some pharmaceutical compounds on aluminum 6063 in 0.5moll?1 H3PO4 has been studied using weight loss and galvanostatic polarization techniques. Results showed that the inhibition occurs through adsorption of the inhibitor molecules on the metal surface. The inhibition efficiency increased with increasing inhibitor concentration, but decreased with increasing temperature. The adsorption of first group pharmaceutical compounds

A. S. Fouda; A. A. Al-Sarawy; F. Sh. Ahmed; H. M. El-Abbasy

2009-01-01

441

On the corrosion resistance of the Delhi iron pillar  

Microsoft Academic Search

The nature of the protective passive layer on the corrosion resistant Delhi iron pillar (DIP) has been addressed based on a detailed characterization of its rust. Rust characterization clearly established that the major constituents of the scale were crystalline iron hydrogen phosphate hydrate (FePO4·H3PO4·4H2O), ?-, ?-, ?-FeOOH and magnetite. The iron oxide\\/oxyhydroxides were present in the amorphous form. The role

R. Balasubramaniam

2000-01-01

442

Extraction studies of Pu(IV) with octylphenyl acid phosphate  

Microsoft Academic Search

Octylphenyl acid phosphate, the commercially available mixture of monooctylphenylphosphoric acid (MOPPA) and dioctylphenylphosphoric acid (DOPPA) in xylene medium has been employed as an extractant for distribution studies on Pu(IV) in different mineral acids including phosphoric acid. It was found possible to extract Pu quantitatively from an acid mixture comprising 2.5M H3PO4, 0.75M H2SO4 and 0.5M HNO3. Quantitative stripping was observed

P. D. Mithapara; V. K. Manchanda; P. R. Natarajan

1984-01-01

443

Organometallic catalysts for primary phosphoric acid fuel cells: Final report, 1981-1985  

SciTech Connect

Cathode improvement, both in performance and cost, available through the use of a class of organometallic cathode catalysts, the tetraazaannulenes (TAAs), was investigated. A new mixed catalyst was identified which provides improved cathode performance without the need for the use of a noble metal. This mixed catalyst was tested under load for 1000 h in full cell at 160 to 200C in phosphoric acid (H3PO4), and was shown to provide stable performance.

Walsh, F.

1987-03-01

444

Effects of topography and composition of titanium surface oxides on osteoblast responses  

Microsoft Academic Search

To investigate the roles of composition and characteristics of titanium surface oxides in cellular behaviour of osteoblasts, the surface oxides of titanium were modified in composition and topography by anodic oxidation in two kinds of electrolytes, (a) 0.2m H3PO4, and (b) 0.03m calcium glycerophosphate (Ca-GP) and 0.15m calcium acetate (CA), respectively. Phosphorus (P: ca.10at%) or both calcium (Ca: 1–6at%) and

Xiaolong Zhu; Jun Chen; Lutz Scheideler; Rudolf Reichl; Juergen Geis-Gerstorfer

2004-01-01

445

Catalytic graphitization of Mo-B-doped polyacrylonitrile (PAN)-based carbon fibers  

Microsoft Academic Search

A novel carbon fiber pretreatment was proposed. Polyacrylonitrile (PAN)-based carbon fibers were first anodized in H3PO4 electrolyte to achieve an active surface, and then coated with Mo-B catalysts by immersed the carbon fibers in a uniformly\\u000a dispersed Mo-B sol. The as-treated carbon fibers were then graphitized at 2 400 °C for 2 h. The structural changes were characterized\\u000a by X-ray

Shi-hai Xu; Feng-ying Zhang; Shao-huan Liu; Dong-mei He; Qing-yun Cai

2010-01-01

446

Patterning of pyramidal recesses in (1 0 0)InP substrate  

Microsoft Academic Search

Symmetrical pyramidal recesses were etched into (100)InP substrate in 3HCl:1H3PO4 at (16±0.05)°C via 20?m×20?m square windows opened in InGaAs. The windows had sides aligned in ?001? and corners tapered along [011] and [01¯1]. The recesses had each of the four sides at the square edges composed of a large ordinary facet (called pyramidal) and a small re-entrant facet. The pairs

P. Eliáš; I. Kosti?; J. Šoltýs

2011-01-01

447

Effect of calcination temperature on the morphology and surface properties of TiO 2 nanotube arrays  

Microsoft Academic Search

Well-ordered TiO2 nanotube arrays were prepared by electrochemical anodization of titanium in aqueous electrolyte solution of H3PO4+NH4F at a constant voltage of 20V for 3h, followed by calcined at various temperatures. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and Photoluminescence (PL) were used to characterize the samples. The results showed that the as-prepared nanotube

Gang Li; Zhong-Qing Liu; Jing Lu; Lei Wang; Zhao Zhang

2009-01-01

448

Hydride vapour phase epitaxy growth and characterization of thick GaN using a vertical HVPE reactor  

Microsoft Academic Search

Growth of 2-inch diameter bulk GaN layers with a thickness up to 2mm is demonstrated in a vertical hydride vapour phase growth reactor. Morphology, dislocations, optical and electrical properties of the material have been investigated using atomic force microscopy, optical microscopy, decorative etching in hot H3PO4, Hall measurements and low-temperature photoluminescence. Atomic force microscopy reveals a two-dimensional step flow growth

C. Hemmingsson; P. P. Paskov; G. Pozina; M. Heuken; B. Schineller; B. Monemar

2007-01-01

449

Agave sisalana, a biosorbent for the adsorption of Reactive Red 120 from aqueous solution  

Microsoft Academic Search

The textile industry is one of the largest producers of dye effluent. Treatment of these effluents has to be cost effective hence a number of precursors have been studied as a viable alternative adsorbent. Sisal fibre was converted to activated carbon by chemical methods. Sisal fibre was activated with different activating agents such as H3PO4, HCl, HNO3, NaOH and KOH.

Venkateshwarapuram Rengaswami Giri Dev; Jayarama Reddy Venugopal; Thamdiannan Senthil Kumar; Lima Rose Miranda; Seeram Ramakrishna

2010-01-01

450

Dechlorination of auto shredder residues.  

PubMed

Dechlorination of ASR (auto shredder residual) wastes has been studied in the present work. ASR was predechlorinated with Ca(OH)(2) extraction as well as dechlorinated with Ca(OH)(2) during incineration or pyrolysis. Experimentally, pre-dechlorination of ASR via extraction of Cl with a Ca(OH)(2) solution (pH 12.5) may reduce Cl contain in the ASR by 15%. Extraction of Cl at elevated temperatures (such as 373 K), interestingly, led to a further reduction of Cl in the ASR to 33.5%. A small amount of HCl and light hydrocarbons (C(1)-C(5)) were yielded during pyrolysis of the ASR in the presence of Ca(OH)(2) at 773 K. On the contrary, 75-85% of Cl may be mineralized (CaCl(2)) with Ca(OH)(2) (or CaO) during incineration at 1100 K. PMID:16996209

Tai, Hua-Shan; Liu, Chia-Ming; Wu, Yun-Jou

2006-08-15

451

Effect of chemical etching on the morphology of anodic aluminum oxides in the two-step anodization process  

NASA Astrophysics Data System (ADS)

Morphological features of the anodic aluminum oxide (AAO) templates fabricated by electrochemical oxidation under different chemical etching conditions were investigated. The chemical etching treatment had a paramount impact on the morphological features of the AAO templates produced with the two-step anodization process. Increasing the etching treatment time was found to be favourable, provided that the ratio of the etching treatment time to that of anodization must be at least one half. Etching solutions based merely on H3PO4 fail to remove the aluminum oxides from the first anodization step. The addition of as much as 2% CrO3 offers a marked improvement in the AAO pore features. Increasing the H3PO4 concentration in H3PO4-CrO3 mixtures improves the pore features while an increase in the CrO3 concentration has no effect. The temperature of the etching solution also affects the morphology of AAO pores remarkably. An etching solution temperature of 55 °C is the optimum.

Erdogan, Pembe; Yuksel, Behiye; Birol, Yucel

2012-03-01

452

Improving the Selectivity of the Phosphoric Acid ?-Elimination on a Biotinylated Phosphopeptide  

NASA Astrophysics Data System (ADS)

This study aims at improving the MALDI-TOF detection of a phosphorylated peptide containing a cysteine residue by ?-elimination of H3PO4 hardly enriched by classical methods. The experimental conditions were optimized on this phosphopeptide (biot-pAdd) and its nonphosphorylated counterpart (biot-Add). The major side-reactions were H2S elimination on the cysteine residues and H2O elimination on the non phosphorylated serine residue of biot-Add. The former dilutes the MALDI-TOF signal for the desired species. The latter gives a product similar to what is obtained by H3PO4 elimination and should prompt to caution when working with a mixture between phosphorylated and non phosphorylated peptides. Modifications on the solvent, the reaction temperature and time, the nature, and concentration of the base were made. Major improvement of the selectivity of the reaction was observed in 30 % ACN, at room temperature for 4 h. However, these optimizations are specific to these sequences and should be performed anew for different peptides. The selectivity of the reaction towards H3PO4 elimination is improved, but the persistence of side-reactions renders a previous sample fractionation necessary. In these optimized conditions, the ionization enhancement is 3-fold and the detection limits for biot-pAdd are similar to biot-Add (100 fmol).

Matheron, Lucrèce; Clavier, Séverine; Diebate, Oumar; Karoyan, Philippe; Bolbach, Gérard; Guianvarc'h, Dominique; Sachon, Emmanuelle

2012-11-01

453

Formation and Dissociation of Phosphorylated Peptide Radical Cations  

NASA Astrophysics Data System (ADS)

In this study, we generated phosphoserine- and phosphothreonine-containing peptide radical cations through low-energy collision-induced dissociation (CID) of the ternary metal-ligand phosphorylated peptide complexes [CuII(terpy) p M]·2+ and [CoIII(salen) p M]·+ [ p M: phosphorylated angiotensin III derivative; terpy: 2,2':6',2''-terpyridine; salen: N, N '-ethylenebis(salicylideneiminato)]. Subsequent CID of the phosphorylated peptide radical cations ( p M·+) revealed fascinating gas-phase radical chemistry, yielding (1) charge-directed b- and y-type product ions, (2) radical-driven product ions through cleavages of peptide backbones and side chains, and (3) different degrees of formation of [M - H3PO4]·+ species through phosphate ester bond cleavage. The CID spectra of the p M·+ species and their non-phosphorylated analogues featured fragment ions of similar sequence, suggesting that the phosphoryl group did not play a significant role in the fragmentation of the peptide backbone or side chain. The extent of neutral H3PO4 loss was influenced by the peptide sequence and the initial sites of the charge and radical. A preliminary density functional theory study, at the B3LYP 6-311++G(d,p) level of theory, of the neutral loss of H3PO4 from a prototypical model— N-acetylphosphorylserine methylamide—revealed several factors governing the elimination of neutral phosphoryl groups through charge- and radical-induced mechanisms.

Kong, Ricky P. W.; Quan, Quan; Hao, Qiang; Lai, Cheuk-Kuen; Siu, Chi-Kit; Chu, Ivan K.

2012-12-01

454

Formation of titanium phosphate composites during phosphoric acid decomposition of natural sphene  

NASA Astrophysics Data System (ADS)

Decomposition of mineral sphene, CaTiOSiO4, by H3PO4 is investigated in detail. During the dissolution process, simultaneous calcium leaching and formation of titanium phosphate (TiP) take place. The main product of decomposition is a solid titanium phosphate silica composite. The XRD, solid-sate NMR, IR, TGA, SEM and BET data were used to identify and characterize the composite as a mixture of crystalline Ti(HPO4)2·H2O and silica. When 80% phosphoric acid is used the decomposition degree is higher than 98% and calcium is completely transferred into the liquid phase. Formation of Ti(HPO4)2·H2O proceeds via formation of meta-stable titanium phosphate phases, Ti(H2PO4)(PO4)·2H2O and Ti(H2PO4)(PO4). The sorption affinities of TiP composites were examined in relation to caesium and strontium ions. A decrease of H3PO4 concentration leads to formation of composites with greater sorption properties. The maximum sorption capacity of TiP is observed when 60% H3PO4 is used in sphene decomposition. The work demonstrates a valuable option within the Ti(HPO4)2·H2O SiO2 composite synthesis scheme, to use phosphoric acid flows for isolation of CaHPO4·2H2O fertilizer.

Maslova, Marina V.; Rusanova, Daniela; Naydenov, Valeri; Antzutkin, Oleg N.; Gerasimova, Lidia G.

2008-12-01

455

Comparing different salt forms of rotigotine to improve transdermal iontophoretic delivery.  

PubMed

The transdermal delivery of a new salt form of the dopamine agonist rotigotine, rotigotine.H(3)PO(4) is presented and compared to rotigotine.HCl. A comparison was made on the level of solubility, passive and iontophoretic delivery. Different aspects of the delivery were investigated: delivery efficiency, maximum flux, donor pH, electro-osmotic contribution and transport number. Changing the salt form from rotigotine.HCl to rotigotine.H(3)PO(4) increases significantly the solubility and rules out the influence of NaCl on the solubility by the absence of the common-ion effect. At low donor concentration, no difference in transdermal delivery was observed between the salt forms. Due to an increase in the maximum solubility of rotigotine.H(3)PO(4), a 170% increase in maximum flux, compared to rotigotine.HCl, was achieved. A balance between solubility and delivery efficiency can be obtained by choosing the correct donor pH between 5 and 6. A slight increase in electro-osmotic contribution and transport number was observed. Using the parameters, determined by modeling the in vitro transport, in vivo simulations revealed that with iontophoresis therapeutic levels can be achieved with a rapid onset time and be maintained in a controlled manner by adjusting the current density. PMID:19969079

Ackaert, O W; Eikelenboom, J; Wolff, H M; Bouwstra, J A

2009-12-05

456

Partial molal volumes and compressibilities of phosphoric acid and sodium phosphates in 0.725 molal NaCl at 25 °C.  

PubMed

The apparent molal volume V(?) and adiabatic compressibility ?(?) of H(3)PO(4), NaH(2)PO(4), Na(2)HPO(4), and Na(3)PO(4) have been determined from density and sound speed measurements in 0.725 m NaCl solutions at 25 °C. The partial molal volumes V(i)* and compressibilities ?(i)* have been determined by extrapolating the values of V(?) and ?(?) to infinite dilution in the NaCl media. The results have been compared to earlier measurements made on a number of electrolytes in NaCl media. The phosphate results showed correlations between the values of V(i)* and ?(i)* as found for other electrolytes. The values for the volume ?V(i) and compressibility ??(i) changes for the dissociation of H(3)PO(4) in 0.725 m NaCl have been calculated from the measurements. The calculated values of ?V(i) and compressibility ??(i) have been used to estimate the effect of pressure K(P)/K(0) on the dissociation of H(3)PO(4) in the oceans using RT ln[K(P)/K(0)] = -?V(i)P + 0.5??(i)P(2), where P is the applied pressure in bars. The results are in reasonable agreement with directly measured values. PMID:21141930

Millero, Frank J; Huang, Fen; Lo Surdo, Antonio; Vinokurova, Faina

2010-07-27

457

Extraction procedures for chemical speciation of arsenic in atmospheric total suspended particles.  

PubMed

An arsenic chemical speciation study was performed in 2000, using air filters on which total suspended particles (TSP) were collected, from the city of Huelva, a medium size city with huge industrial influence in SW Spain. Different procedures for extraction of the arsenic species were performed using water, NH2OH.HCl, and H3PO4 solutions, with either microwave or ultrasonic radiation. The best optimised extraction methods were use of 100 mmol L(-1) NH2OH.HCl and 10 mmol L(-1) H3PO4 and microwave radiation for 4 min. High-performance liquid chromatography coupled with hydride generation and atomic fluorescence spectrometry (HPLC-HG-AFS) was employed for determination of the arsenic species. The results from 12 TSP air filters collected on a monthly basis showed extraction was quantitative (94% with NH2OH.HCl and 86% H3PO4). Only inorganic arsenic species (arsenite and arsenate) were detected. The mean arsenite concentration was 1.2+/-0.3 ng m(-3) (minimum 0.3 ng m(-3), maximum 1.8 ng m(-3)). The mean arsenate concentration was 10.4+/-1.8 ng m(-3), with greater monthly variations than arsenite (minimum 2.1 ng m(-3), maximum 30.6 ng m(-3)). The high level of arsenic species in the TSP samples can be related to a copper smelter located in the region. PMID:15827716

Oliveira, Vanesa; Gómez-Ariza, José Luis; Sánchez-Rodas, Daniel

2005-04-13

458

Exchange of oxygen isotopes in carbon dioxide-phosphoric [correction of phosporic] acid systems.  

PubMed

The rate of exchange of isotopes of oxygen between solutions of concentrated phosphoric acid and CO2 was measured as a function of temperature, acid strength (pressure of water in equilibrium with the solution), pressure of CO2, and surface area of the reaction vessel. At 75 degrees C, significant exchange was found to occur even for the "anhydrous" phosphoric acids, those in which the nominal percentage of H3PO4 in solution is equal to or exceeds 100%. Exchange is much slower at 25 degrees C, but isotopic shifts as large as 0.1% can be observed in 95% H3PO4 at equilibration times approaching 1000 hr. Rates of exchange were found to be dependent upon the vapor pressure of water in equilibrium with the acid solutions. Exchange was found to occur primarily on the surface of the reaction vessel above the solution, with no dependence on total CO2 pressure. These observations indicate that phosphoric acids with nominal concentrations of H3PO4 approaching 105% are preferable for the minimization of exchange between CO2 samples and acid solutions during phosphorolyses of carbonate materials. Moreover, with such acids, significant time--temperature trade-offs are possible, allowing rapid preparation of CO2 at elevated temperatures. PMID:11542004

Wachter, E A; Hayes, J M

1985-01-01

459

Absolute determination of electrolytic conductivity for primary standard KCl solutions from 0 to 50°C  

Microsoft Academic Search

An absolute determination of aqueous electrolytic conductivity has been made for primary standards 0.01D and 0.1D (demal) potassium chloride solutions over the temperature range of 0 to 50°C in 5 degree intervals. A cell with a removable center section of accurately known length and area was used for the measurements. Values were adjusted to be in conformity with the ITS-90

Y. C. Wu; W. F. Koch

1991-01-01

460

Volume regulation and KCl cotransport in reticulocyte populations of sickle and normal red blood cells  

Microsoft Academic Search

The potassium chloride co-transporter (KCC) is a member of the electroneutral cation chloride family of cotransporters found in multiple tissues that are involved in transepithelial ion transport and regulation of intracellular ion content and cell volume. We have shown previously that three of the four KCC genes – KCC1, KCC3, and KCC4 – are expressed in red blood cells (RBC)

Maa-Ohui Quarmyne; Mary Risinger; Andrew Linkugel; Anna Frazier; Clinton Joiner

2011-01-01