Response Surface Method Analysis on Electro-Enhanced Technique for Remediation of Cadmium Contaminated Soil

2020 ◽  
Vol 980 ◽  
pp. 502-511
Author(s):  
Yu Shan Wan ◽  
Ju An Zhai ◽  
An Wei Wang
Keyword(s):  
Energy Consumption ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Water Content ◽  
Contaminated Soil ◽  
Removal Rate ◽  
Electrokinetic Remediation ◽  
Surface Method ◽  
Remediation Time

In view of the problems of long remediation time, high energy consumption and low remediation efficiency in electrokinetic remediation of heavy metal contaminated soil, Cd was used to simulate heavy metals in contaminated soil, and response surface method (RSM) was used to optimize the factors influencing electrokinetic remediation. Central Composite (CCD) experimental design method was taken to study the effects of electric field strength, remediation time and water content on removal rate of Cd in soil. Also, polynomial regression mathematical model and optimal reaction conditions were provided for Cd pollution in electrokinetic soil remediation. The simulated equation F was 15.67, the correlation coefficient was 0.9338, and the adjustment correlation coefficient was 0.9042, indicating good regression and strong significance of the equation. The model results showed that, for the optimal experimental conditions, electric field strength was 2.25V·cm-1, the remediation time was 120.79h, and the water content was 17.06%. On the basis of such reaction condition, intermittent current flow method was adopted d to further enhance the electrokinetic remediation effect. The cadmium removal rate in the soil was increased by 3.17%, 2.86% and 2.43%, respectively, and the electric energy consumption was decreased by 10.54%, 11.28% and 9.97%, respectively, suggesting that the method could effectively improve the removal rate of Cd and reduce energy consumption.

Water-Activated Bacterial Cellulose-Based Electrorheological Fluids and Electromechanical Response of Artificial Muscle Based on Electrorheological Fluids and Siloxane Gel

2009 ◽  
Vol 87-88 ◽  
pp. 143-148
Author(s):  
Nai Xu ◽  
De Min Jia
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Water Content ◽  
Bacterial Cellulose ◽  
Yield Stress ◽  
Particle Concentration ◽  
Electrorheological Fluids ◽  
Water Yield ◽  
Composite Gel

Electrorheological (ER) characteristics of ER fluids (ERF) containing bacterial cellulose (BC) particles in silicone oil was investigated as a function of particle water content, DC electric field strength and particle concentration. It was found that the existence of water in BC particles strongly influenced the performance of water-activated ERF based on BC particles. Around 8.8 wt% water, yield stress reached its maximum valve of 1118 Pa after which it decreased with increasing water content. At the same water content, yield stress increased linearly with increasing in either electric field strength or particle concentration. The ERF based on BC particles was introduced into the poly (dimethylsiloxane) (PDMS) gels to prepare electric field sensitive composite gel. Electric fields were applied to these composite gels using flexible electrodes. Compressions of these gels with varying PDMS/ERF ratios were confirmed by the electrode displacement. It was found that 50/50 PDMS/ERF gel exhibited the maximum displacement of 102um at 2 kV/mm electric field.

scholarly journals Experimental Study on the Performance of a Novel Compact Electrostatic Coalescer with Helical Electrodes

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1733
Author(s):  
Yi Shi ◽  
Jiaqing Chen ◽  
Zehao Pan
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Water Content ◽  
Water Droplet ◽  
Separation Process ◽  
Water Droplets ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water

As most of the light and easy oil fields have been produced or are nearing their end-life, the emulsion stability is enhanced and water cut is increasing in produced fluid which have brought challenges to oil–water separation in onshore and offshore production trains. The conventional solution to these challenges includes a combination of higher chemical dosages, larger vessels and more separation stages, which often demands increased energy consumption, higher operating costs and larger space for the production facility. It is not always feasible to address the issues by conventional means, especially for the separation process on offshore platforms. Electrostatic coalescence is an effective method to achieve demulsification and accelerate the oil–water separation process. In this paper, a novel compact electrostatic coalescer with helical electrodes was developed and its performance on treatment of water-in-oil emulsions was investigated by experiments. Focused beam reflectance measurement (FBRM) was used to make real-time online measurements of water droplet sizes in the emulsion. The average water droplet diameters and number of droplets within a certain size range are set as indicators for evaluating the effect of coalescence. We investigated the effect of electric field strength, frequency, water content and fluid velocity on the performance of coalescence. The experimental results showed that increasing the electric field strength could obviously contribute to the growth of small water droplets and coalescence. The extreme value of electric field strength achieved in the high-frequency electric field was much higher than that in the power-frequency (50 Hz) electric field, which can better promote the growth of water droplets. The initial average diameters of water droplets increase with higher water content. The rate of increment in the electric field was also increased. Its performance was compared with that of the plate electrodes to further verify the advantages of enhancing electrostatic coalescence and demulsification with helical electrodes. The research results can provide guidance for the optimization and performance improvement of a compact electrocoalescer.

scholarly journals Optimum Shape Design of Metal-Enclosed 550 kV Disconnectors Based on Response Surface Method and Finite Element Analysis

2015 ◽  
Vol 5 (4) ◽  
pp. 818-824
Author(s):  
R. Gong ◽  
S. Wang ◽  
X. Luo ◽  
M. Danikas
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Response Surface ◽  
Optimum Shape ◽  
Shape Design ◽  
Optimal Result ◽  
Surface Method

In this paper, the optimum shape design of 550 kV disconnectors in Gas Insulated Switchgears (GIS) are firstly presented employing the Finite Element Method (FEM) for electric field analysis coupled with an optimal design method. For effective analysis, the FEM is conducted in transient quasistatic electric field, using a finite element FORTRAN code. The structure parameters of disconnectors that provide the required electric field strength are obtained by the Response Surface Method (RSM) and the optimal values are presented by the variation in maximal electric field strength. The RSM and optimal design methods are also conducted by FORTRAN codes. The optimal result reveals that a uniform electric field distribution is achieved in 550 kV disconnectors. Additionally, the optimal result of disconnectors is verified by the proposed disconnector undertaken power frequency withstanding voltage of 740 kV for 1 minute, lightening impulse of 1675 kV, and operating impulse of 1300 kV, respectively.

Effect of Pulsed Electric Field on Freeze-Drying of Potato Tissue

2014 ◽  
Vol 10 (4) ◽  
pp. 857-862 ◽  
Author(s):  
Yali Wu ◽  
Dongguang Zhang
Keyword(s):  
Energy Consumption ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Pulse Width ◽  
Unit Area ◽  
Pulsed Electric Field ◽  
Pulse Number ◽  
Drying Rate ◽  
Drying Time

Abstract The influence of pulsed electric field (PEF) on the drying behavior of potato was investigated, and the optimal parameters were determined. Drying experiments were conducted with different PEF pre-treatments. The effects of process parameters of PEF pre-treatment were examined with respect to drying rate, drying time, productivity per unit area, and energy consumption. Results showed that the three parameters investigated were significant in the following sequence: pulse number, electric field strength, and pulse width. The optimal electric field strength, pulse width, and pulse number were 1,500 V cm−1, 120 μs, and 45 pulses, respectively. Under these optimal conditions, productivity per unit area increased by 32.28%, specific energy consumption decreased by 16.59%, drying time was shortened by 31.47%, and drying rate improved by 14.31% compared with the control group.

Optical Measurement of the Electric Field Strength in a Gel Insulator

2016 ◽  
Vol 136 (10) ◽  
pp. 1420-1421
Author(s):  
Yusuke Tanaka ◽  
Yuji Nagaoka ◽  
Hyeon-Gu Jeon ◽  
Masaharu Fujii ◽  
Haruo Ihori
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Optical Measurement

Effect of external magnetic field on lane formation in driven pair-ion plasmas

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Swati Baruah ◽  
U. Sarma ◽  
R. Ganesh
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Coupling Parameter ◽  
Critical Parameters ◽  
Coulomb Coupling ◽  
Lane Formation ◽  
Parameter Values

Lane formation dynamics in externally driven pair-ion plasma (PIP) particles is studied in the presence of external magnetic field using Langevin dynamics (LD) simulation. The phase diagram obtained distinguishing the no-lane and lane states is systematically determined from a study of various Coulomb coupling parameter values. A peculiar lane formation-disintegration parameter space is identified; lane formation area extended to a wide range of Coulomb coupling parameter values is observed before disappearing to a mixed phase. The different phases are identified by calculating the order parameter. This and the critical parameters are calculated directly from LD simulation. The critical electric field strength value above which the lanes are formed distinctly is obtained, and it is observed that in the presence of the external magnetic field, the PIP system requires a higher value of the electric field strength to enter into the lane formation state than that in the absence of the magnetic field. We further find out the critical value of electric field frequency beyond which the system exhibits a transition back to the disordered state and this critical frequency is found as an increasing function of the electric field strength in the presence of an external magnetic field. The movement of the lanes is also observed in a direction perpendicular to that of the applied electric and magnetic field directions, which reveals the existence of the electric field drift in the system under study. We also use an oblique force field as the external driving force, both in the presence and absence of the external magnetic field. The application of this oblique force changes the orientation of the lane structures for different applied oblique angle values.

scholarly journals Investigating the feasibility of cerebellar transcranial direct current stimulation to facilitate post-stroke overground gait performance in chronic stroke: a partial least-squares regression approach

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Dhaval Solanki ◽  
Zeynab Rezaee ◽  
Anirban Dutta ◽  
Uttama Lahiri
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Chronic Stroke ◽  
Least Squares Regression ◽  
Significance Level ◽  
Gait Performance ◽  
Wilcoxon Rank Sum Test ◽  
Gait Parameters ◽  
The Mean

Abstract Background Investigation of lobule-specific electric field effects of cerebellar transcranial direct current stimulation (ctDCS) on overground gait performance has not been performed, so this study aimed to investigate the feasibility of two lobule-specific bilateral ctDCS montages to facilitate overground walking in chronic stroke. Methods Ten chronic post-stroke male subjects participated in this repeated-measure single-blind crossover study, where we evaluated the single-session effects of two bilateral ctDCS montages that applied 2 mA via 3.14 cm2 disc electrodes for 15 min targeting (a) dentate nuclei (also, anterior and posterior lobes), and (b) lower-limb representations (lobules VIIb-IX). A two-sided Wilcoxon rank-sum test was performed at a 5% significance level on the percent normalized change measures in the overground gait performance. Partial least squares regression (PLSR) analysis was performed on the quantitative gait parameters as response variables to the mean lobular electric field strength as the predictors. Clinical assessments were performed with the Ten-Meter walk test (TMWT), Timed Up & Go (TUG), and the Berg Balance Scale based on minimal clinically important differences (MCID). Results The ctDCS montage specific effect was found significant using a two-sided Wilcoxon rank-sum test at a 5% significance level for 'Step Time Affected Leg' (p = 0.0257) and '%Stance Time Unaffected Leg' (p = 0.0376). The changes in the quantitative gait parameters were found to be correlated to the mean electric field strength in the lobules based on PLSR analysis (R2 statistic = 0.6574). Here, the mean electric field strength at the cerebellar lobules, Vermis VIIIb, Ipsi-lesional IX, Vermis IX, Ipsi-lesional X, had the most loading and were positively related to the 'Step Time Affected Leg' and '%Stance Time Unaffected Leg,' and negatively related to the '%Swing Time Unaffected Leg,' '%Single Support Time Affected Leg.' Clinical assessments found similar improvement in the TMWT (MCID: 0.10 m/s), TUG (MCID: 8 s), and BBS score (MCID: 12.5 points) for both the ctDCS montages. Conclusion Our feasibility study found an association between the lobular mean electric field strength and the changes in the quantitative gait parameters following a single ctDCS session in chronic stroke. Both the ctDCS montages improved the clinical outcome measures that should be investigated with a larger sample size for clinical validation. Trial registration: Being retrospectively registered.

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