Separation of vanadium(V) using N235 by three-phase system in concentrated HCl media

2017 ◽  
Vol 95 (6) ◽  
pp. 717-722 ◽  
Author(s):  
Chun Shen ◽  
Yimin Zhang ◽  
Jing Huang ◽  
Shenxu Bao ◽  
Xiao Yang ◽  
...  
Keyword(s):  
Organic Phase ◽  
Extraction Efficiency ◽  
Inhibitory Effect ◽  
Phase System ◽  
Phase Form ◽  
The Third ◽  
Third Phase ◽  
Vanadium Extraction ◽  
Three Phase ◽  
Ftir Spectral Analysis

The third phase formed in the process of extracting vanadium in a N235/HCl system was usually regarded as a limit to the throughput of the plant. To have a deep insight on this problem, the formation of the third phase in the extraction of vanadium by tertiary amine N235 in the concentrated HCl system was studied. The optimum parameters of three-phase system extraction were determined, and FTIR analysis was carried out to characterize the structure of extracted complexes and analyze the mechanism of formation and elimination of the third phase. The results showed that vanadium extraction efficiency was 86.5% with 20% v/v N235 and a phase ratio (O:A) of 1:2 in 2 min at 25 °C, though an obvious third phase was found within the experimental HCl concentration range. Cl− is the participant in the process of increasing the vanadium extraction efficiency, whereas H+ has an inhibitory effect on vanadium extraction. Meanwhile, the structure of the extracted complex was confirmed as (R3N)m(HCl)m+x·([Formula: see text])·(H2O)n through a solvation mechanism with molecular association, which was further proved by FTIR spectral analysis. Furthermore, the limited solubility of the ion-extracted complexes in the nonpolar solvent kerosene made the third-phase form. The third phase disappeared when phase modifier (about 5% v/v TBP) was added into the organic phase, as the polarity of the organic phase increased.

An Analytical Model for the Effective Dielectric Constant of a 0-3-0 Composite

2010 ◽  
Author(s):  
K. A. Cook-Chennault ◽  
S. Banerjee
Keyword(s):  
Dielectric Constant ◽  
Aspect Ratio ◽  
Analytical Model ◽  
Experimental Results ◽  
Effective Dielectric Constant ◽  
The Third ◽  
Third Phase ◽  
Three Phase ◽  
Phase 0 ◽  
Experimental Values

An analytical expression for prediction of the effective dielectric constant of a three phase 0-3-0 ferroelectric composite is presented. The analytical results are verified with the experimental results from Nan et al [1]. We extend the analytical model, so that the influence of the shape of the third phase inclusion, on the effective dielectric constant of the composite, can be investigated. The results indicate that the dielectric constant increases ∼7 times, when the aspect ratio of the conductive inclusion is increased from 1 (sphere) to 10 (spheroid). The analytical predictions compare favorably with the experimental values.

N,N,N′,N′-Tetra-Methyl-3-Oxy-Pentane-1,5-Diamide (TMPDA): A Promising Back Extractant for Ln(III) and Zr(IV)

2010 ◽  
Author(s):  
Meng Wei ◽  
Qian’ge He ◽  
Xuegang Liu ◽  
Jing Chen
Keyword(s):  
Crystal Structure ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Extraction Efficiency ◽  
Phase Distribution ◽  
Decomposition Temperature ◽  
Water Soluble ◽  
Phase System ◽  
Acid System ◽  
Equilibrium Aqueous Phase

Water-soluble oxa-diamide ligand, N,N,N′,N′-tetra-methyl-3-oxy-pentane-1,5-diamid (TMPDA) has been synthesized and purified. Its crystal structure, melting point, decomposition temperature, solubilities in aqueous phase and organic phase, distribution ratio between aqueous and organic phase, etc. are reported. The effect of TMPDA concentration in aqueous phase and HNO3 concentration in the equilibrium aqueous phase on the extraction efficiency of La(III), Ce(III), Pr(III), Nd(III), Zr(IV), Fe(III), Y(III), Mo(VI), Ru(III) and Pd(II) by 30% TRPO/kerosene have been studied. The results indicate that TMPDA dissolve well in aqueous phase but almost insoluble in kerosene or 30%TRPO/kerosene in the bi-phase system. It can effectively reduce the extraction of Ln(III), Y(III) and Zr(IV) into 30%TRPO/kerosene at a moderate acid system (0.24mol/L∼0.27mol/L HNO3). TMPDA is a promising stripping agent for Ln(III), Y(III) and Zr(IV) from loaded TRPO.

Chemoenzymatic Epoxidation of α-Pinene Catalyzed by Novozym 435

2013 ◽  
Vol 634-638 ◽  
pp. 896-900 ◽  
Author(s):  
Cheng Zou ◽  
You Yan Liu ◽  
Yi Ming Qin ◽  
Ai Xing Tang ◽  
Li Na Lan
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Phase ◽  
Octanoic Acid ◽  
Novozym 435 ◽  
Phase System ◽  
In Situ Oxidation ◽  
Novozyme 435 ◽  
Three Phase ◽  
Novozym 435 Lipase

The synthesis of α-pinene oxide mediated by Novozym 435 (lipase from Candida antarctica) in a three-phase system was studied in this work. Novozyme 435 catalysed the formation of peroxyoctanoic acid directly from octanoic acid and hydrogen peroxide, which was then applied for in situ oxidation of α-pinene. The highest conversion of a-pinene (approximately 80%) was obtained when the reaction was performed at 30°C and initial hydrogen peroxide concentration in the water phase was set to be 30%. The parameters affecting the lipase activity were also investigated，where the peracid generated in organic phase was obvserved to greatly inactivate the enzyme compared to other components in the organic phase.

scholarly journals ω-Transaminase-Mediated Asymmetric Synthesis of (S)-1-(4-Trifluoromethylphenyl)Ethylamine

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 307
Author(s):  
Carlos J. C. Rodrigues ◽  
Manuel Ferrer ◽  
Carla C. C. R. de Carvalho
Keyword(s):  
Enzyme Activity ◽  
Organic Phase ◽  
Process Development ◽  
Enzyme Reaction ◽  
Building Blocks ◽  
Inhibitory Effect ◽  
Chiral Amines ◽  
Phase System ◽  
Two Phase ◽  
Chiral Amine

The pivotal role played by ω-transaminases (ω-TAs) in the synthesis of chiral amines used as building blocks for drugs and pharmaceuticals is widely recognized. However, chiral bulky amines are challenging to produce. Herein, a ω-TA (TR8) from a marine bacterium was used to synthesize a fluorine chiral amine from a bulky ketone. An analysis of the reaction conditions for process development showed that isopropylamine concentrations above 75 mM had an inhibitory effect on the enzyme. Five different organic solvents were investigated as co-solvents for the ketone (the amine acceptor), among which 25–30% (v/v) dimethyl sulfoxide (DMSO) produced the highest enzyme activity. The reaction reached equilibrium after 18 h at 30% of conversion. An in situ product removal (ISPR) approach using an aqueous organic two-phase system was tested to mitigate product inhibition. However, the enzyme activity initially decreased because the ketone substrate preferentially partitioned into the organic phase, n-hexadecane. Consequently, DMSO was added to the system to increase substrate mass transfer without affecting the ability of the organic phase to prevent inhibition of the enzyme activity by the product. Thus, the enzyme reaction was maintained, and the product amount was increased for a 62 h reaction time. The investigated ω-TA can be used in the bioconversion of bulky ketones to chiral amines for future bioprocess applications.

scholarly journals Meso Trajectories in the National Innovation System and Their Regulation

2020 ◽  
Author(s):  
Oleg Golichenko
Keyword(s):  
Public Policy ◽  
Innovation System ◽  
Evolutionary Selection ◽  
The Third ◽  
Third Phase ◽  
Three Phase ◽  
Knowledge Rules ◽  
Innovative Behaviour ◽  
Two Phases ◽  
Phase Process

The mesotrajectory is presented as a three-phase process of the development of mesopopulations: emergence (origination), diffusion (acceptance, assimilation and adaptation) and retention of a new rule (innovation). The central category of the NIS, i.e. knowledge, is considered from two positions: as a set of specific rules and as the most critical innovation resource. The proposed methodology also describes the three phases of mesostructure dividing each of them into two series–parallel sub-phases and incorporating them in the design of niches, technological and market ones. The methodology allows specifying the effect of the evolutionary selection and intermittent development of meso-units in the first two phases, as well as the mechanisms of changing the socio-technological regime in the third phase. The study set and analyse policy for creating motivation for innovative behaviour at different phases of the mesotrajectory. The actors’ mesopopulation are represented as carriers of the properties of knowledge-rules-resources. The knowledge of the actor is taking into account not only as a rule but a factor breaking the mesotrajectory. Among other characteristics of mesotrajectory discontinuity, intermittent equilibrium is taken into consideration in the study. The problem of regulating trajectory continuity is analysed in the framework of public policy.

scholarly journals Performance Analysis of Signaled Intersections to Improve Safety in Depok Intersection, Depok City

2019 ◽  
Author(s):  
Sony Widyawan ◽  
Darul Prayogo ◽  
Rukman . ◽  
Diajeng Ayu D P ◽  
Abdul Rokhim
Keyword(s):  
Traffic Congestion ◽  
Good Condition ◽  
Phase 3 ◽  
Service Levels ◽  
The Third ◽  
Third Phase ◽  
Three Phase ◽  
Traffic Conflicts ◽  
Traffic Conflict ◽  
Selection Of

Transportation problems are one of the issues faced in Depok, especially at intersections. The problems of traffic congestion and conflict often occur at intersections, especially at Depok intersection in which one of the efforts made to reduce the conflicts is made by managing the intersection. The method used in analyzing intersection performance is the use of calculations at IHCM, while the analysis of traffic conflicts to determine the seriousness of traffic conflicts is to use traffic conflict techniques (TCT) compared to the conflicts. Recommendations are made with a scheme using the selection of 3 phases and 3.5 phases then making a comparison with the third phase and choosing the most appropriate scenario. From the recommendation scheme made using the VISSIM 10 PTV software, the most appropriate scheme is obtained by using three-phase settings. The results of phase 3 simulations are effective in reducing the number of traffic conflicts and service levels are still in good condition.

scholarly journals A Three-Phase Multiobjective Mechanism for Selecting Retail Stores to Close

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Rong-Chang Chen ◽  
Shu-Ping Suen
Keyword(s):  
Genetic Algorithm ◽  
Information System ◽  
Clustering Algorithm ◽  
Retail Store ◽  
Second Phase ◽  
Considerable Influence ◽  
Multiobjective Genetic Algorithm ◽  
The Third ◽  
Third Phase ◽  
Three Phase

To operate a successful and growing business, a retail store manager has to make tough decisions about selectively closing underperforming stores. In this paper, we propose using a three-phase multiobjective mechanism to help retail industry practitioners determine which stores to close. In the first phase, a geographic information system (GIS) andk-means clustering algorithm are used to divide all the stores into clusters. In the second phase, stores can be strategically selected according to the requirements of the company and the attributes of the stores. In the third phase, a neighborhood-based multiobjective genetic algorithm (NBMOGA) is utilized to determine which stores to close. To examine the effectiveness of the proposed three-phase mechanism, a variety of experiments are performed, based partly on a real dataset from a stock-list company in Taiwan. Results from the experiments show that the proposed three-phase mechanism can help efficiently decide which store locations to close. In addition, the neighborhood radius has a considerable influence on the results.

Investigation of Viscosity and Thermodynamic Properties on the Bioleaching Solution with and without Mesophilic Bacteria

2007 ◽  
Vol 20-21 ◽  
pp. 149-151
Author(s):  
Mei Lin Liu ◽  
Ren Man Ruan ◽  
Jian Kang Wen ◽  
Dian Zuo Wang
Keyword(s):  
Thermodynamic Properties ◽  
Extraction Efficiency ◽  
Free Energies ◽  
Mesophilic Bacteria ◽  
The Third ◽  
Third Phase ◽  
Third Phase Formation ◽  
The Mean ◽  
Mean Ionic Activity Coefficients ◽  
Ubbelohde Viscometer

In this study, the viscosities and conductivities of bioleaching solution were determined by Ubbelohde viscometer and conductivity meter, respectively. The mean ionic activity coefficients, relative partial molar free energies of copper bioleaching solution at above experimental temperatures ranging from 298 K to 313 K have been calculated. Simultaneously, these characters of copper bioleaching solution were compared with and without mesophilic bacteria. The experimental data showed that the viscosities and thermodynamic properties for bioleaching solution would be crucial to minimize the third phase formation so as to increase extraction efficiency.

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