scholarly journals Densities and electrochemical potential window of the BaCl2-NaCl-NaF-AlF3 electrolyte

2020 ◽  
Vol 48 (5-6) ◽  
pp. 413-422
Author(s):  
VERONIKA KESTOUTCHE LAURINAVICHYUTE ◽  
LEONID VITAL’EVICH PUGOLOVKIN ◽  
EDUARD EVGEN’EVICH LEVIN ◽  
DMITRY ALEXANDROVICH SIMAKOV
Keyword(s):  
Experimental Design ◽  
Electrochemical Potential ◽  
Redox Potentials ◽  
Cryolite Ratio ◽  
Electrode Processes ◽  
Linear Behavior ◽  
Melt Density ◽  
Melt Composition ◽  
Main Electrode ◽  
Three Factor

The effect of melt composition (BaCl2-NaCl-NaF-AlF3) on its density, resistivity and redox potentials of the main electrode processes is reported. A three-factor two-level experimental design was used to study the effects of cryolite ratio (1.1-1.6) and BaCl2 (0-60wt%) or NaCl (0-10wt%) content on the melt density. The obtained equation satisfactorily describes the measured melt densities. The observed non-linear behavior of melt density with BaCl2 additions is assigned to the formation of BaClF complex. Unlike BaCl2, additions of 0-10 wt% NaCl have little effect on the melt density, however, affect the melt conductivity significantly.

A Critical Evaluation of the Redox Properties of Uranium, Neptunium and Plutonium Ions in Acidic Aqueous Solutions

1999 ◽  
Vol 71 (9) ◽  
pp. 1771-1807 ◽  
Author(s):  
Sorin Kihara ◽  
Zenko Yoshida ◽  
Hisao Aoyagi ◽  
Kohji Maeda ◽  
Osamu Shirai ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Redox Reactions ◽  
Critical Evaluation ◽  
Redox Properties ◽  
Redox Processes ◽  
Redox Potentials ◽  
Electrode Processes ◽  
Reversible Redox ◽  
Reduction Mechanisms ◽  
Current Potential

Standard redox potentials, E0s, and redox processes of U, Np and Pu ions in acidic aqueous solutions are reviewed and evaluated critically. The E0sof reversible redox processes, MO22+/MO2+ and M4+/M3+ (M: U, Np or Pu) adopted are those proposed mainly by Riglet et al. on the basis of the precise correction of formal potentials, E0's, according to the improved theoretical approach to estimate the activity coefficient. Electrode processes of the U, Np and Pu ions are discussed in terms of current-potential curves, measured so far by polarography, voltammetry or flow coulometry. Special attention is payed to the irreversible MO2+/M4+ reactions. Disproportionation reactions of MO2+ are also discussed. New substances are introduced as intermediates during reductions of MO2+ to M4+ or disproportionations of MO2+.CONTENTSIntroductionStandard redox potentials for uranium, neptunium and plutonium ions in acidic aqueous solutions2.1 Evaluation of E0 from E0' determined by electrochemical measurements2.2 Temperature dependence of E0Redox reactions of uranium, neptunium and plutonium in acidic aqueous solutions investigated by polarography or voltammetry3.1 Uranium3.2 Neptunium3.3 Plutonium3.4 Disproportionation of NpO2+, PuO2+, Np4+ and Pu4+3.5 Reduction of MO2+ and reduction intermediatesRedox reactions of uranium, neptunium and plutonium in acidic aqueous solutions investigated by flow coulometry4.1 Electrode processes of the uranium, neptunium and plutonium ions investigated by flow coulometry at the column electrode at the column electrode4.2 Disproportionation of MO2+ during the electrolysis by flow coulometry4.3 Reduction mechanisms of MO2+ (M = Np or Pu) and reduction intermediates investigated by flow coulometryConclusionsList of abbreviationsAppendixReferences

scholarly journals Effects of Solospun Roller on Properties of Cotton/Polyester Solo-Sirofil Composite Yarn

2012 ◽  
Vol 7 (3) ◽  
pp. 155892501200700 ◽  
Author(s):  
Rui-Hua Yang ◽  
Wei-Mian Wu ◽  
Hong-Bo Wang ◽  
Yu-Qin Wan ◽  
Chun-Ping Xie ◽  
...  
Keyword(s):  
Experimental Design ◽  
Surface Characteristics ◽  
Groove Depth ◽  
Groove Width ◽  
Orthogonal Experimental Design ◽  
Composite Yarn ◽  
Roller Diameter ◽  
Polyester Composite ◽  
Three Factor

The surface characteristics of a solospun roller are important to the properties of solo-sirofil yarns. In this research, a three-level, three-factor, orthogonal experimental design (33) was used to investigate the effect of a solospun roller diameter, groove width and groove depth on the hairiness of cotton/polyester composite yarn. Solo-sirofil yarns with different solospun rollers were produced, and the hairiness was tested. It was shown that the hairiness of the solo-sirofil composite yarn was reduced by 44% compared to that of the sirofil. The structure of the solo-sirofil was improved when the thickness of the groove is 0.2 mm, with an alternating depth of 0.3 mm and 0.4 mm, a width of 0.5 mm and a roller diameter of 13 mm.

Tuning the Electrochemical Potential of Perfunctionalized Dodecaborate Clusters Through Vertex Differentiation

2018 ◽  
Author(s):  
Alex I. Wixtrom ◽  
Zeeshan Parvez ◽  
Miles A. Savage ◽  
Elaine A. Qian ◽  
Dahee Jung ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Electrochemical Potential ◽  
Oxidation States ◽  
Redox Potentials ◽  
New Class ◽  
Redox Active ◽  
Active Vertex ◽  
Post Functionalization

We report a new class of redox-­‐active vertex-­‐differentiated dodecaborate clusters featuring pentafluoroaryl groups. These [B12(OR)11NO2] clusters share several unique photophysical properties with their [B12(OR)12] analogues, while exhibiting significantly higher (+0.5 V) redox potentials. This work describes the synthesis, characterization, and isolation of [B12(O-­‐CH2C6F5)11NO2] clusters in all 3 oxidation states (dianion, radical, and neutral). Reactivity to post-­‐functionalization with thiol species via SNAr on the pentafluoroaryl groups is also demonstated.

scholarly journals Fermentation characteristics of elephant grass silages with macaúba cake

2018 ◽  
Vol 40 (1) ◽  
pp. 42523 ◽  
Author(s):  
Cíntia Gonçalves Guimarães ◽  
Caroline Salezzi Bonfá ◽  
Antônio Ricardo Evangelista ◽  
Alexandre Soares dos Santos ◽  
Lílian De Araújo Pantoja ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Experimental Design ◽  
Filamentous Fungi ◽  
Fermentation Process ◽  
Anaerobic Fermentation ◽  
The Other ◽  
Elephant Grass ◽  
Linear Behavior ◽  
Randomized Experimental Design ◽  
Different Levels

 The elephant grass presents problems during the fermentation of the ensiled material, being necessary use of additives. This study aimed to evaluate the population of yeast and filamentous fungi, enterobacterias, contents of acetic and butyric acids and ethanol production, in elephant grass silages added with different levels of macaúba cake at opening times. This was a 3 x 6 factorial completely randomized experimental design, with three inclusion levels of the macaúba cake (0, 10 and 20%) and six opening times (1, 5, 10, 20, 40 and 60 days after ensiling), with four replications. For all the studied variables, there was a difference in the interaction among levels and times, and an increasing linear behavior only for the contents of acetic acid, for the other variables, the behavior was quadratic. The elephant grass silages produced acetic acid, which in turn inhibited the production of yeast and filamentous fungi. There was a small development of enterobacterias only in the first opening times, and low production of butyric acid and ethanol, which indicated a material with good fermentative characteristics. The macaúba cake contributed to improve the anaerobic fermentation process, but it was not as expressive for the parameters evaluated in this work. 

Silver as anode in cryolite—alumina-based melts

2007 ◽  
Vol 61 (2) ◽  
Author(s):  
M. Kucharík ◽  
P. Chamelot ◽  
L. Cassayre ◽  
P. Taxil
Keyword(s):  
Melting Point ◽  
Oxygen Evolution ◽  
Anodic Process ◽  
Cryolite Ratio ◽  
Working Temperature ◽  
Lower Melting Point ◽  
Anodic Behaviour ◽  
Acidic Electrolyte ◽  
The Stability ◽  
Melt Composition

AbstractThe anodic behaviour of silver was investigated in cryolite—alumina-based melt. Silver has a lower melting point (ca. 960°C) than the other metals considered as possible inert materials for aluminium electrolysis. The working temperature used in aluminium industry is approximately 960°C, depending on the melt composition. Therefore, the stability of silver during the anodic process was tested at 870°C in an acidic electrolyte consisting of 65.5 mass % Na3AlF6 + 22.9 mass % AlF3 + 5.7 mass % CaF2 + 3.9 mass % LiF + 2 mass % Al2O3 with the melting point ca. 850°C. The electrolyte without alumina was prepared as well, with the melting point ca. 860°C. The resulting cryolite ratio (CR = n(NaF)/n(AlF3)) for both electrolytes was equal to 1.6. The behaviour of the silver anode was studied by voltammetry measurements. The electrochemical study showed that an oxidation reaction occurred at a potential below the oxygen evolution potential. Silver was not found to be stable under oxygen evolution. The degradation of the silver anode was apparent after electrolysis.

scholarly journals A Mathematical Model for the Alkylation of o-Cresol with Cyclohexanol

1970 ◽  
Vol 44 (2) ◽  
pp. 181-186
Author(s):  
M Ashaduzzaman ◽  
Manoranjan Saha ◽  
Shams Tania Afroza Islam ◽  
Mohammad Ismail ◽  
Nashid Sharif ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Experimental Design ◽  
Perchloric Acid ◽  
Molar Ratio ◽  
Suggested Model ◽  
Critical Response ◽  
Stirring Time ◽  
Main Effects ◽  
Factor Interaction ◽  
Three Factor

A mathematical model was developed for the alkylation of o-cresol with cyclohexanol in the presence of perchloric acid as a catalyst. A set of trials was planned according to a 3 factor 2-level Yates pattern experimental design. The variables chosen for the study were temperature, molar ratio of o-cresol to cyclohexanol and amount of perchloric acid. The critical response was the yield of cyclohexyl o-cresol. Main effects as well as two-and three-factor interaction effects were statistically significant. The adequacy of the suggested model was checked up. The highest experimentally found yield was 89.3% while the estimated yield was found to be 89.09%. The experimentally settings were temperature, 140O C; molar ratio of o-cresol to cyclohexanol, 6:1; amount of catalyst, 5% by wt. of o-cresol; addition time, 2 h; stirring time, 1 h. Keywords: o-Cresol, Cyclohexanol, Experimental design, Alkylation. DOI: 10.3329/bjsir.v44i2.3669 Bangladesh J. Sci. Ind. Res. 44(2), 181-186, 2009

scholarly journals Optimization of Slow Pyrolysis of Bamboo for Biochar Production using Taguchi’s L9 Orthogonal Array

2021 ◽  
Vol 287 ◽  
pp. 02004
Author(s):  
MNZ Moni ◽  
Suzana Yusuf ◽  
ASA Manaf ◽  
Waqiuddin Rahman
Keyword(s):  
Particle Size ◽  
Experimental Design ◽  
Reaction Temperature ◽  
Flow Rate ◽  
Orthogonal Array ◽  
Char Yield ◽  
Nitrogen Flow ◽  
Signal To Noise ◽  
Nitrogen Flow Rate ◽  
Three Factor

This paper investigates the effects of three parameters (reaction temperature, feedstock particle size and nitrogen flow rate) towards the solid (char) yield from the pyrolysis of bamboo. Three-factor, three-level Taguchi’s L9 Orthogonal Array was used as the experimental design. The char yield at reaction temperatures of 300-500°C, feedstock particle size of 100-1000 μm, and nitrogen flow rate of 100-300 ml min−1 were investigated. The maximum solid yield was predicted based on signal-to-noise (S/N) ratio and was found to be at 300°C reaction temperature, 1000 μm feedstock particle size and 100 ml min−1 of nitrogen flow rate. Confirmation runs were conducted to validate the prediction at corresponding predicted conditions.

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