Effect Of High Voltage Electric Field Research Articles

Effect of High-Voltage Electric Field on Thawing Kinetics and Quality Characteristics of Frozen Beef

This study investigated the impact of high-voltage electric field (HVEF) thawing technology on the thawing rate, water retention characteristics, microstructure, and nutritional composition of thawed beef. Compared with the control group, in which thawing occurred under natural conditions, the experimental group, in which beef was thawed under HVEF (12 kV, 16 kV, 20 kV, 24 kV, 28 kV), showed a significantly shorter thawing time, and the higher the voltage was, the faster the thawing rate. The total loss rate of thawed beef reached its minimum value of (54.2 ± 0.62) % at 28 kV, and the water retention of the experimental group was significantly better than that of the control group (p < 0.05). Therefore, it can be concluded that HVEF thawing enhances the water retention ability of beef. In a color comparison, it was evident that the color of the beef thawed by HVEF was significantly better than that of the control group. The results of scanning electron microscopy (SEM) indicated that thawing beef by HVEF can reduce the damage to the myofibril structure. Low-field nuclear magnetic resonance (LF-NMR) showed that beef thawed by HVEF had a significantly increased bound water content. According to the determination of malondialdehyde content, beef thawed by HVEF had a reduced degree of lipid oxidation; the content at 16 kV was 2.4 mg/kg, and the degree of lipid oxidation was the lowest. Fourier transform infrared (FTIR) spectroscopy analysis revealed that the absorption peak positions of the beef samples did not show significant changes under different conditions. However, the absorption peak intensity in the experimental group was generally higher than that in the control group. Examination of the protein secondary structure via infrared spectroscopy revealed that, compared with the control group, HVEF thawing transformed the proteins from an ordered structure to a disordered structure. The increase in disordered structure reduced the fiber gap of the sample and improved the water retention of the beef. The above experimental results indicate that HVEF thawing can improve the water-holding capacity of the sample and reduce the thawing damage to the quality of the sample.

1.2\xa0MV/cm pulsed electric fields promote transthyretin aggregate degradation

Numerous theoretical studies have been conducted on the effects of high-voltage electric fields on proteins, but few have produced experimental evidence. To acquire experimental data for the amyloid disassemble theory, we exposed transthyretin aggregates to 1 ns 1.26 MV/cm pulsed electric fields (PEFs) to promote transthyretin degradation. The process produced no changes in pH, and the resulting temperature increases were < 1 °C. We conclude that the physical effects of PEFs, rather than thermal or chemical effects, facilitate aggregate degradation.

Effects of high-voltage electric field produced by an improved electrode system on freezing behaviors and selected properties of agarose gel

This work aimed at evaluating the effects of high-voltage electric field (HVEF) produced by an improved electrode system on the freezing behaviors and selected properties of agarose gel. The freezing of the agarose gel was realized by a Peltier cooler coupled with an improved electrode system. The electrode system was integrated with a dielectric spacer having high permittivity to avoid partial discharges. Results showed that HVEF combined with a low freezing rate significantly reduced the supercooling degree, enhanced the average freezing rate in particular the nucleation rate, and higher internal electric field intensity showed a better microstructure with smaller ice crystals in frozen samples. Under the highest applied voltage of 9 kV (Ein = 1.09 E+05 V/m) tested in this study, a 100% supercooling release was achieved. Maximum reductions of 78.83%, 25.79% and 28.75% were observed for the nucleation time, tempering time and total freezing time, respectively, while the phase transition time was prolonged by 14.86% as compared with the control (p < 0.05). Some reinforcement was detected in the gel strength by increasing internal electric field intensity, but not significant enough to prevent the structural damage and syneresis caused by freezing and thawing. This study suggested that HVEF-assisted freezing was able to reduce the size of ice crystals formed in semi-solid model foods, and the integration of a dielectric spacer with high permittivity to the electrode could be used as a potential method to solve the electrical discharge problem.

The effects of high-voltage electric field on microbial communities in paddy soil

The effects of high-voltage electric field on microbial communities in paddy soil

Effect of high-voltage electric field on formaldehyde diffusion within building materials

An experimental study concerning the diffusion of formaldehyde within building material in different high-voltage electric fields was conducted. Formaldehyde concentration was tested under electric field intensities of 0, 33.3, 66.6 and 100 kV/m. The Capsule Concentration Footprint Method (CCFM) was proposed to analyse the resulting experimental data. It was found that both equilibrium concentration and emission rate increased under greater electric field intensity. In addition, the experimental data indicated that high-voltage electric fields have a significant effect on partition coefficient, little effect on initial concentration and nearly no influence on diffusion coefficient. The partition coefficient decreased remarkably, while initial concentrations increased slowly due to the increasing electric field intensity. A formula was obtained to explain the relationship between partition coefficient and electric field intensity. A simulation of the adsorption between the formaldehyde and building material was conducted to illustrate the decrease in adsorption potential due to the greater electric field intensity, which helps to understand the principle established by the experimental data. The results of this study confirmed the feasibility of a new method for the reduction of formaldehyde in the man-made boards.

Laboratory Setup for Studying Cellular Responses to High-Voltage Pulsed Electric Field

A model of a device for studying the effects of high-voltage electric fields on biological objects in aqueous solution, showing the range of output parameters, is described. A scheme for the device was developed, on which basis an existing experimental model was assembled for subsequent testing in a laboratory setup.

High-voltage electric-field-induced growth of aligned “cow-nipple-like” submicro-nano carbon isomeric structure via chemical vapor deposition

In this study, a novel vertically aligned carbon material, named “cow-nipple-like” submicro-nano carbon isomeric structure, was synthesized by the thermal decomposition of C2H2 in a chemical-vapor deposition system with a high-voltage external electric field. The microstructures were characterized by using scanning electron microscopy, high-resolution transmission electron microscopy, and Raman spectroscopy, respectively. The results revealed that (1) the total height of the carbon isomeric structure was in a rang of 90-250 nm; (2) the carbon isomeric structure consisted of a submicro- or nano-sized hemisphere carbon ball with 30-120 nm in diameter at the bottom and a vertically grown carbon nanotube with 10-40 nm in diameter upon the carbon ball; (3) there was a sudden change in diameter at the junction of the carbon ball and carbon nanotube. In addition, the carbon isomeric structure showed an excellent controllability, that is, the density, height, and diameter could be controlled effectively by adjusting the precursor ferrocene concentration in the catalytic solution and C2H2 ventilation time. A possible growth model was proposed to describe the formation mechanism, and a theoretic calculation was carried out to discuss the effect of high-voltage electric field upon the growth of the carbon isomeric structure.

Improvement of Soft Clays by High-Voltage Electrokinetics

The theory of high-voltage electrokinetics in clay-water-electrolyte systems was developed. Upon application of a nonuniform high-voltage direct-current (DC) field to a clay-water-electrolyte system through electrically insulated electrodes, electrophoretic and dielectrophoretic forces are generated and imposed on clay particles. The former are induced by the interaction of a DC field with negatively charged clay particles, whereas the latter are induced by the interaction of the electrical diffuse double layer in a nonuniform electric field. The effects of high-voltage electric fields to the properties of a disturbed marine sediment were investigated in an experimental program. The primary experimental data indicate that high-voltage electrokinetics increased undrained shear strength of a marine sediment up to 267% and the pullout resistance of steel plates up to 88%. The effect of high-voltage electrokinetics was irreversible even long after withdrawal of the electric fields. The treatment was energy efficient and had minimal electrochemical reactions due to insulation of the electrodes.