scholarly journals Electric Volume Resistivity for Biopolyimide Using 4,4′-Diamino-α-truxillic acid and 1,2,3,4-Cyclobutanetetracarboxylic dianhydride

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1552 ◽  
Author(s):  
Shunsuke Kato ◽  
Fitri Adila Amat Yusof ◽  
Toyohiro Harimoto ◽  
Kenji Takada ◽  
Tatsuo Kaneko ◽  
...  
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Film Thickness ◽  
Electric Field Strength ◽  
Dimethyl Ester ◽  
Volume Resistivity ◽  
Electric Resistivity ◽  
Experimental Conditions ◽  
Drying Time ◽  
Truxillic Acid

Biopolyimides poly(ATA-CBDA), made from of 4,4′-diamino-α-truxillic acid dimethyl ester (ATA) and 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), is synthesized and measured its electric volume resistivity at various experimental conditions. The effects of film size, thickness, drying time, and the electric field strength on electric resistivity are investigated and compared with polyimide (Kapton). The electric resistivity for all polyimide and biopolyimide are distributed in the range of 1015–1016 Ωcm, which shows that biopolyimide has high electrical insulation as well as polyimide. The electric resistivity strongly depends on film thickness, which suggests that electric resistivity is a function of electric field strength. The critical electric field for polyimide and biopolyimide films are determined to be 5.8 × 107 V/m and 3.2 × 107 V/m, respectively. Humidity was found to strongly affect the electric resistivity; ~1016 Ωcm at 34% RH and ~1013 Ωcm at 60% RH for both polyimide and biopolyimide films.

Dependence of Paper Surface and Volume Resistivity on Electric Field Strength

2008 ◽  
Vol 52 (3) ◽  
pp. 030501 ◽  
Author(s):  
P. Sirviö ◽  
K. Backfolk ◽  
R. Maldzius ◽  
J. Sidaravicius ◽  
E. Montrimas
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Volume Resistivity ◽  
Paper Surface

scholarly journals Pulsed electric field pre-treatment efficiency analysis in processes of biomaterials drying

2019 ◽  
Vol 80 (4) ◽  
pp. 49-54 ◽  
Author(s):  
I. A. Shorstkii ◽  
D. A. Khudyakov
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Mathematical Models ◽  
Electric Field Strength ◽  
Pulsed Electric Field ◽  
Convective Drying ◽  
Efficient Production ◽  
Drying Process ◽  
Drying Time ◽  
Pre Treatment

The transition to an efficient economy and efficient production requires building the foundations for the development of energy efficient technologies and the drying of biomaterials to convert them into useful products. The purpose of this work is to analyze the effectiveness of pretreatment with a pulsed electric field (PEF) in the process of convective drying of biomaterials. The PEF was processed with electric field strength of 2, 4 and 6 kV/cm, the number of pulses 500, with a pulse duration of 50 ?s. Based on the electrical conductivity data of the biomaterial, the index of the disintegration 56% was determined before and after the PEF treatment, which confirms the existence of an electroporation mechanism of the material structure. The drying process is presented with a description of various mathematical models. PEF pre-treatment with the parameters of electric field strength 4 and 6 kV / cm and the number of impulses 500 allowed to reduce the drying time by 13.8% for the value E = 0.02. Total time spent on the drying process reduced by 20-25 minutes. It should be noted that the total energy spent on PEF pre-treatment (<150 W / kg) compared with the energy spent on the drying process is incommensurably small. Statistical analysis of the considered mathematical models showed good convergence of most models with experimental data. The considered technology of pretreatment of PEF can ensure the effective processing of biomaterials in the required amount to obtain high-quality and safe products. Obtained data of the kinetics process can be used to the mathematical model of the drying process design with the use of preliminary treatment processing.

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.

scholarly journals Cell Permeabilisation, Microstructure and Quality of Dehydrated Apple Slices Treated with Pulsed Electric Field During Blanching

2018 ◽  
Vol 4 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Om Prakash Chauhan ◽  
Shima Shayanfar ◽  
Stefan Topefl
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Pulsed Electric Field ◽  
Cell Permeabilization ◽  
Electron Microscopic ◽  
Drying Time ◽  
Apple Slices ◽  
Microscopic Studies

ABSTRACTEffect of pulsed electric field as a blanching pretreatment on cell permeabilization, microstructure and quality of dehydrated apple slices was studied. Apple slices were pulsed electric field pretreated (1.0, 1.5 and 2.0 kV/cm using 25 and 75 pulses) at a temperature of 60 and 80°C in water followed by dehydration at 60°C in a cabinet dryer. Cell disintegration index was found to increase significantly (p<0.05) with increase in the electric field strength, number of pulses and blanching temperature and thereby reducing the drying time. The dehydrated slices showed lower hardness and higher lightness (L*) values for the samples treated at higher electric field strength for longer durations. Scanning electron microscopic studies of samples revealed better retention of cellular integrity when pre-treated at a low level of PEF (1.0 kV/cm using 25 pulses) and blanched at low temperature (60°C). However, the samples treated to a level of 1.5 kV/cm and 75 pulses of PEF with subsequent blanching temperature 80°C was found to yield optimum cell permeabilization. The study suggests that PEF can be used as an effective blanching pretreatment for achieve good quality dehydrated apple slices in less drying time. 

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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