Effect Of High Electric Field Research Articles

Effect of low and high pulsed electric field on the quality and nutritional minerals in cold boned beef M. longissimus et lumborum

The present research investigated the effects of low PEF (LPEF, 2.5 kV, 200 Hz and 20 μs) and high PEF (HPEF, 10 kV, 200 Hz and 20 μs) on the quality of cold-boned beef loins at 1 and 14 days of post-treatment. HPEF increased (P < 0.001) the temperature of the beef M. longissimus et lumborum (LL) samples. HPEF samples had higher (P = 0.007) shear force than LPEF samples and control samples were not different from either. HPEF beef LL samples had higher L* values and lower a* values (P < 0.001) compared to LPEF and control samples. Higher lipid oxidation (P = 0.013) was found in HPEF samples compared to LPEF samples. Lower (P < 0.01) P, K and Fe concentrations were found in HPEF samples compared to LPEF samples. The results suggest that high intensity PEF treatment can negatively affect the quality of beef.

Time-Dependent Breakdown Mechanisms and Reliability Improvement in Edge Terminated AlGaN/GaN Schottky Diodes Under HTRB Tests

In this letter, we investigate the time-dependent breakdown mechanisms in edge terminated AlGaN/GaN lateral Schottky diodes under high-temperature reverse bias (HTRB) tests. Thanks to a combined experimental/simulation analysis, we ascribe the device failure to two distinct time-sequential breakdown mechanisms caused by a localized electric field peak at the edge termination corner. In particular, the combined effect of high electric field and temperature causes a first breakdown of the plasma-enhanced atomic layer deposition (PEALD)-Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> followed by a second one in the AlGaN barrier. To validate this hypothesis, a 2-D TCAD simulator was used, and the breakdown path in Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> was modeled by an inclusion of a narrow metal filament. The electrical simulations well reproduce the characteristics of the fresh and degraded GaN diodes. Finally, we demonstrate that the diode reliability under HTRB tests can be significantly improved by using a metalorganic chemical vapor deposition (MOCVD)-Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> dielectric in the edge termination. This reliability improvement is related to a better material quality of MOCVD-Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> , showing a higher breakdown field compared with the PEALD-Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> .

Effect of high voltage electric field on structure and property of PEDOT : PSS film

Low electrical conductivity of PEDOT : PSS film is to some extent a limit for its wide application. To solve this problem, the high voltage electric field was used to improve the film's electrical conductivity and its effects on the film's structure and properties were investigated. The PEDOT : PSS film was prepared on quartz substrate with spin coating. Visible light transmittance of the prepared film was tested with UV-Visible spectroscopy and chemical structure was measured with Fourier transform Raman spectroscopy (FTRM). The surface morphology was characterized with AFM, and electrical conductivity was measured with Hall effects measurement. The results showed that with the increase of the electric field, the electrical conductivity of PEDOT : PSS film was boosted rapidly at first, and then improved slowly when the electric field was above 200 kV/m. The film's electrical conductivity improved more than 17 times in total from 0.51&amp;#183;10-3 up to 8.92&amp;#183;10-3 S/m. However, the film's visible light transmittance decreased only a little with the increase of the electric field, not more than 3&amp;#37;. In addition, despite little change in the chemical structure of the PEDOT : PSS film, its surface roughness increased significantly with the increase of the electric field intensity. DOI: 10.21883/FTP.2017.12.45183.8553

Effects of High Intensity Pulsed Electric Fields or Thermal Treatments and Refrigerated Storage on Antioxidant Compounds of Fruit Juice-Milk Beverages. Part II: Carotenoids

Effects of high intensity pulsed electric fields (HIPEF) or thermal treatments over carotenoids of mixed beverages were evaluated after processing and during refrigerated storage. Nine carotenoids were identified in all samples, being β-carotene the major compound. Just after processing, concentration of most individual carotenoids diminished around 6–30% in fruit juice-skim milk (FJ-SM) and fruit juice-whole milk (FJ-WM) beverages; except, 9-cis-violaxanthin-neoxanthin, antheraxanthin and phytoene-phytofluene which increased in the thermally treated FJ-SM (5–19%) and 9-cis-violaxanthin-neoxanthin which also augmented in HIPEF processed FJ-SM (24%). Total carotenoid (TC) content decreased (6–13%) in both beverages, irrespectively of the treatment applied. Through the storage, individual carotenoid concentration varied widely in all beverages, depending on the carotenoid structure; however, TC tended to decrease. Nonetheless, changes observed HIPEF-treated beverages were less than those in the conventionally pasteurized ones. Hence, HIPEF is as effective treatment, or even more, than heat processing to preserve bioactive compounds in mixed beverages. Practical Applications Nowadays, modern population is claiming for products with high antioxidant properties and attractive flavor. In this sense, mixed beverages formulated with fruit juices and milk are attracting the attention of consumers due to their exotic taste and their elevated concentration of bioactive substances, such as carotenoids. However, these compounds are very susceptible to heat and are easily degraded during processing and storage. Hence, finding preservation technologies for mixed beverages capable to maintain their carotenoid concentration as high as possible after treatment and during shelf-life is one of the greatest challenges for the food industry. In this sense, the relevance of this study is to demonstrate that high intensity pulsed electric fields processing is a potential alternative to thermal pasteurization in order to obtain not only safe but nutritious fruit juice-mixed beverages with elevated concentration of carotenoids, especially those with pro-vitamin A activity, such as β-carotene.

Quantitative Analysis of Plant Growth Exposed to Electric Fields

Electromagnetic radiations present in the environment has a profound effect on the growth of vegetable plant primarily grown under the high power transmission lines. The high electric field generated due to ultra high voltage causes the increase and reduction in the size of the plants. Numerous research have been carried out to investigate the effect of electric field on the plants. However, the knowledge in term of quantitative analysis on the effect of electric field on the growth of vegetables is not entirely understood. Thus, this paper presents a study conducted to investigate the effect of high voltage DC electric fields on the young vegetables growth namely ‘Choy Sam’ and bean sprout. The experimental setup was designed which composed of two parallel plate electrodes. This research was focused on the percentage of germination and growing rate of young vegetables . The growth of the young vegetables during exposure was calculated by using statistical methods. The analysis of the results showed that the electric fields and the electric fields treated water have influenced the germination rate and height of stems of both young vegetables causing the increase in stem height.

Quantitative analysis of plant growth exposed to electric fields

Electromagnetic radiations present in the environment has a profound effect on the growth of vegetable plant primarily grown under the high power transmission lines. The high electric field generated due to ultra high voltage causes the increase and reduction in the size of the plants. Numerous research have been carried out to investigate the effect of electric field on the plants. However, the knowledge in term of quantitative analysis on the effect of electric field on the growth of vegetables is not entirely understood. Thus, this paper presents a study conducted to investigate the effect of high voltage DC electric fields on the young vegetables growth namely ‘Choy Sam’ and bean sprout. The experimental setup was designed which composed of two parallel plate electrodes. This research was focused on the percentage of germination and growing rate of young vegetables. The growth of the young vegetables during exposure was calculated by using statistical methods. The analysis of the results showed that the electric fields and the electric fields treated water have influenced the germination rate and height of stems of both young vegetables causing the increase in stem height.

A subnanosecond electric pulse exposure system for biological cells.

An exposure system adapted for use on a microscope stage was constructed for studying the effects of high electric field, subnanosecond pulses on biological cells. The system has a bandpass of 3GHz and is capable of delivering high-voltage electric pulses (6.2kV) to the electrodes, which are two tungsten rods (100μm in diameter) in parallel with a gap distance of 170μm. Electric pulses are delivered to the electrodes through a π network, which serves as an attenuator as well as an impedance matching unit to absorb the reflection at the electrodes. By minimizing the inductance of the pulse delivery system, it was possible to generate electric fields of up to 200kV/cm with a pulse duration of 500ps at the surface of the cover slip under the microscope. The electric field at the cover slip was found to be homogenous over an area of 50-70μm. Within this area, neuroblastoma cells placed on the cover slip were studied with respect to membrane potential changes caused by subnanosecond pulses. This allowed us, for the first time, to demonstrate depolarization of the cell membrane potential.

Ionic structure in liquids confined by dielectric interfaces.

The behavior of ions in liquids confined between macromolecules determines the outcome of many nanoscale assembly processes in synthetic and biological materials such as colloidal dispersions, emulsions, hydrogels, DNA, cell membranes, and proteins. Theoretically, the macromolecule-liquid boundary is often modeled as a dielectric interface and an important quantity of interest is the ionic structure in a liquid confined between two such interfaces. The knowledge gleaned from the study of ionic structure in such models can be useful in several industrial applications, such as in the design of double-layer supercapacitors for energy storage and in the extraction of metal ions from wastewater. In this article, we compute the ionic structure in a model system of electrolyte confined by two planar dielectric interfaces using molecular dynamics simulations and liquid state theory. We explore the effects of high electrolyte concentrations, multivalent ions, dielectric contrasts, and external electric field on the ionic distributions. We observe the presence of non-monotonic ionic density profiles leading to a layered structure in the fluid which is attributed to the competition between electrostatic and steric (entropic) interactions. We find that thermal forces that arise from symmetry breaking at the interfaces can have a profound effect on the ionic structure and can oftentimes overwhelm the influence of the dielectric discontinuity. The combined effect of ionic correlations and inhomogeneous dielectric permittivity significantly changes the character of the effective interaction between the two interfaces.

Quantitative Analysis of Plant Growth Exposed to Electric Fields

&lt;p&gt;Electromagnetic radiations present in the environment has a profound effect on the growth of vegetable plant primarily grown under the high power transmission lines. The high electric field generated due to ultra high voltage causes the increase and reduction in the size of the plants. Numerous research have been carried out to investigate the effect of electric field on the plants. However, the knowledge in term of quantitative analysis on the effect of electric field on the growth of vegetables is not entirely understood. Thus, this paper presents a study conducted to investigate the effect of high voltage DC electric fields on the young vegetables growth namely ‘Choy Sam’ and bean sprout. The experimental setup was designed which composed of two parallel plate electrodes. This research was focused on the percentage of germination and growing rate of young vegetables. The growth of the young vegetables during exposure was calculated by using statistical methods. The analysis of the results showed that the electric fields and the electric fields treated water have influenced the germination rate and height of stems of both young vegetables causing the increase in stem height.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Effect of High Electric Field on Secondary Structure of Wheat Gluten

The effect of a high electric field on secondary structure conformation of fully hydrated (45.65% wet basis) gluten protein was studied by Fourier transform infrared spectroscopy. Three experimental conditions were evaluated including electric field intensity of 0 kV (no treatment), 3.5 kV, and 7kV and treatment time of 30, 60, and 90 min. Fourier transform infrared spectra of treated and non-treated hydrated gluten protein revealed that high electric field treatment resulted in irreversible changes in the secondary structures. For the 30 min treatment no variation was observed for electric field intensities 0 and 7 kV; but at 3.5 kV it showed slight reorganization and structural conversion of secondary structures. No variation in spectral pattern was observed for all the high electric field treatments for 60 min but major secondary structure reorganization took place for high electric field treatment at 90 min. Curve-fitting using Gaussian band shapes and principal component analysis further supported the results.

Effect of Thermal and High Electric Fields on Secondary Structure of Peanut Protein

This study evaluated the effect of the thermal and high electric field stresses on the secondary structure conformation of peanut protein using Fourier transform infrared spectroscopy. The amide I region between the wavelengths 1700–1600 cm–1 of the spectra were studied for different thermal and high electric field treatments. Within thermal treatments, both hot air roasting and microwave processing treatments were evaluated. Hot air treatments were performed at temperatures of 50, 75, and 100°C from 15, 30, and 45 min while the microwave treatments were conducted at the same temperatures, but for 5, 10, 15, and 20 min. Three experimental conditions were evaluated for the electric field intensity of 10, 15, and 20 kV for 60, 120, and 180 min. Changes were observed at 1654–1650 cm–1, indicating conformational changes in the α-helix secondary structure. Similar changes were observed at various other wavelengths indicating changes in the 3/10 helix, β-sheets and random coils present in the protein. With an increase in the treatment time, the secondary structure reorganizations increased with the creation of new random coils and aggregated strands. Curve-fitting using Gaussian band shapes further supported the observations. In vitro protein digestibility studies were also performed and the protein changes also supported the observations from the spectra.

The influence of low frequency of external electric field on nucleation enhancement of hen egg-white lysozyme (HEWL)

Protein crystal nucleation processes are drawing increasing interests in both academic and industrial communities. Electric field is a promising means, due to its versatility and easy application, among various external fields that may lead to controllable desired protein crystal nucleation. Different from literature reported experimental and theoretical studies that examined the effects of high frequency electric fields; this work was focused on the low frequency range. For this purpose, Hen-White Lysozyme crystal nucleation from its aqueous solution was used as the model system. We found by experiments that the nucleation rate is non-monotonously dependent on electric field frequency less than 1kHz, which may be ascribed to the mutual orientation modification between neighbor protein molecules induced by the external low frequency, and is different from the case of high frequencies that influence the intermolecular interactions.

The influence of interfaces and intra-band transitions on the band gap of CdS/HgS and GaN/X (X=InN, In0.33Ga0.67N) core/shell/shell quantum dot quantum well – A theoretical study

A theoretical model is presented to calculate the 1s–1s transition energy of an exciton in spherically layered semiconductor quantum-dot quantum-well (QDQW), based on the LCAO variational method using effective mass approximation. The confinement energies of electron and hole and the Coulombic interaction energy between them are calculated for CdS/HgS/CdS, GaN/X/GaN (X=InN, In0.33Ga0.67N) (QDQW) with core/shell/shell structures. The results of the proposed model effectively accommodates the polarization effects at the interfaces of different semiconductor materials in a core/shell/shell structure and elucidates the significant influence of interfaces on the band gap with consistency among previous theoretical and experimental results. The wave function of exciton studied shows significant differences with other theory. The change in the band gap of QDQW is attributed to the exciton excitations by thermal occupation of the lowest dark exciton states at different temperatures. In addition, based on Quantum Confined Stark Effect (QCSE) the effect of high electric field on the charge carriers and the corresponding changes in the band gap has been investigated. The applied electric field provides strong overlap between the electron and hole wave functions as well as increases the binding energy of the exciton, which eventually decreases the band gap.

Fluorinated Graphene FETs Controlled by Ionic Liquid Gate

Fluorinated graphene field effect transistors (FETs) with an ionic liquid (IL) top-gate are demonstrated. Fluorinated graphene functionalized with different fluorine concentrations were prepared. Highly fluorinated graphene FETs controlled by ionic liquid gating (ILG) exhibited higher on/off ratios than pristine (non-fluorinated) graphene FET, while conventional back gating (BG) configuration resulted in lower on/off ratios. ILG can induce high charge density in fluorinated graphene with localized states because of extremely high electric field effect of an electric double layer between IL and fluorinated graphene. Thus, a higher on/off ratio was obtained by the combination of graphene fluorination and ILG.

Effects of high electric field on low-velocity gas-solid two-phase flow movement

It is of significance to study the movement of solid - gas mixed flow of small particle size in the high electric field region for explaining such insulation accidents as contamination deposition, gap breakdown, unknown flashovers, and the like occurring on power line insulators surface. Based on artificial simulation experiments, we applied the particle image velocimetry (PIV) technology to investigate the flow-electric field coupling movement of low-speed mixed flow, comprehensively compare the effects of electric field uniformity, voltage levels, wind speed and other factors on the distribution of flow field. The results show that the effect of non-uniform electric field on the flow field is apparently stronger than that of uniform electric field. It increases with the applied electric field increasing, and decreases a little with the wind speed increasing. In the uniform electric field, the particles have a trend to move to the cathode plate, while in the non-uniform electric field, they are evidently charged under the action of corona and prone to moving toward the anode plate. In contrast, the effect of the AC electric field on the flow field is weaker than that of the DC electric field. However, it still has obvious manifestation. These relevant conclusions play an active role for in-depth research on the external insulation characteristics of HV power grid in sand dust environments such as pollution deposition and distribution on the surface of insulation string, breakdown of the air gap, etc., especially the charged mechanism of small sized dust and sand particles.

The effect of high frequency electric field on enhancement of chondrogenesis in human adipose-derived stem cells.

Osteoarthritis (OA) is globally one of the most common diseases from the middle age onwards. Cartilage is an avascular tissue therefore it cannot be repaired in the body. Conservative treatments have failed as a good remedy and cell therapy as a decisive cure is needed. One of the best and easily accessible cell sources for this purpose is adipose-derived stem cells which can be differentiated into chondrocytes by tissue engineering techniques. Chemical and physical inducers have a key role in stem cell - chondrocyte differentiation. We have tried to determine the role of electric fields (EF) in promoting this kind of chondrogenesis process. Human adipose derived stem cells (ADSCs) were extracted from subcutaneous abdominal adipose tissue during cesarean section. A high frequency (60 KHz) EF (20 mv/cm), as a physical inducer for chondrogenesis in a 3D micromass culture system of ADSCs was utilized. Also, MTT, ELISA, flow cytometry, and real-time PCR techniques were used for this study. We found that using physical electric fields leads to chondrogenesis. Furthermore, results show that using both physical (EF) and chemical (TGFβ3) inducers simultaneously, has best outcomes in chondrogenesis, and expression of SOX(9) and type II collagen genes. It also causes significant decreased expression of type I and X collagen genes in pure EF group compared with control group. The EF was found as a proper effective inducer in chondrogenic differentiation of human ADSCs micromass culture.

Surface potential decay dynamic characteristics of negative-corona-charged fibrous dielectric materials

The dielectric behavior of an insulating material is commonly characterized by exposing its surface to a DC corona discharge for relatively short duration and then recording the decay of the electric potential Vs at its surface, Vs = f(t). The representation of the surface potential decay (SPD) by using tdVs/dt = f(log t) plots has already been used to perform a finer analysis of the dielectric response of film insulators. The present paper takes advantage of this peculiar way of representing the SPD in view of characterizing the dielectric behavior of fibrous electrets negatively-charged from a triode-type (wire-gridplate) electrode system. The experiments were performed in ambient air (temperature: 20 ± 1 °C), at various values of the relative humidity (range 25 % to 65%). This paper reports experimental data collected on a polypropylene (PP) film (sheet thickness: 250 μm) and two types of PP non-woven media (fabric thickness: 300 μm), characterized by different fiber diameters (20 μm and 4 μm). The initial surface potential and the dynamics of SPD of fibrous dielectric materials were found to be affected by the corona charging conditions (relative humidity of the ambient air, grid voltage and grid current), as well as by the properties of the fibers and the structure of the non-woven media. An appropriate model of SPD should take into account charge injection from the media-electrode interface, charge transport controlled by bulk mechanisms and local high electric field effects due to the porous structure of the media.

Effects of High Electric Fields on the Magnitudes of Current Steps Produced by Single Particle Displacement Damage

Measurements of single particle displacement damage are presented as discrete increases in reverse-biased diode leakage current, or current steps, caused by individual heavy ions in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">252</sup> Cf-irradiated JFET diodes. The maximum size of measured current steps agrees with calculations obtained from the expression for Shockley-Read-Hall generation when the radiation-induced defect density is derived from Monte Carlo simulations of atomic displacements and the electric field enhancement of defect emission is taken into account. The distribution of the current steps shows good agreement with experimental data.

The High DC Electric Field Effects on the Dielectric Behavior of Barium Strontium Titanate Ceramics

BaxSr1-xTiO3 (x=0.4, 0.5, 0.6) ceramics were fabricated by the conventional solid-state reactions method. The temperature dependences of the dielectric constant and tunability were investigated under high DC electric field. It was found that the change of dielectric constant and tunability under the applied electric field were closely related to ferroelectric phase, phase transition region and paraelectric phase states. The Curie temperature (Tc) was gradually shifted to higher temperature and were broadened and depressed with increasing of DC electric field. The tunability dependence of temperature exhibits different trends in a wide temperature range and reaches a maximum value near the ferroelectric-paraelectric phase transition. These results may be helpful in understanding the mechanism of dielectric response under higher electric field.

Distortion of Uniform Electric Field by Human Body of Technical Personal in Substations with Super High Voltages 330-500 kv

For protection electric substations personnel from harmful effects of the super high voltage electric field, it is need to measure the level and time of electric field exposition of personal by using mobile electric field measurement instrument. The instrument are placed in mans helmet close to a head in area of high electric field intensity. Standards for limited vales of electric field intensity are estimated for undistorted electric field. As a conductor, the human body distorts the original electric field around the body and device shows distorted value of electric field. Investigation of level distortion by the finite element method and the experimental measurements shows that the maximum distortion appears with change of height of the person and at change parameters of foot ware soil. These parameters, height of the person and foot ware soil data should be used for design of a measurement devise and for adjustment the device before measurements. Change of other person parameters can be ignored because of very law level of changes field distortion.