Amount Of Electric Charge Research Articles

Deterioration of static mechanical properties of RC beams due to bond damage induced by electrochemical rehabilitation

Electrochemical rehabilitation (ER) techniques are very efficient and non-destructive methods to improve the durability of existing concrete structures. However, the induced bond damage between steel bar and concrete will affect the mechanical properties. In order to investigate the effect of ER on the static mechanical properties of concrete structures, three types of tests after electrochemical chloride extraction and bidirectional electromigration were carried out in this study. Based on the desired constitutive models, finite element analysis was then used to verify the effect of bond damage on the static mechanical properties of RC beams. Results showed that the spacing and width of cracks both increased with increasing current density and duration. The yield bearing capacity of beams decreased by 20% when the electrical parameters were 3 A/m2 for 4 weeks and 5 A/m2 for 2 weeks. Careful investigation with experiments, finite element simulations, and theoretical explanation demonstrated that bond damage was the main reason. As a result, a modified flexural stiffness model of concrete beams considering the electrification parameters was established. Combined with data from the relevant literature, the optimal quantity of electric charge for ER balancing chlorine removal efficiency and flexural stiffness was finally determined as 500–1400 Ah/m2.

MR Imaging Enables Real-Time Monitoring ofInVitro Electrolytic Ablation of Hepatocellular Carcinoma.

To evaluate the capability of T2-weighted magnetic resonance (MR) imaging to monitor electrolytic ablation-induced cell death in real time. Agarose phantoms arranged as an electrolytic cell were exposed to varying quantities of electric charge under constant current to create a pH series. The pH phantoms were subjected to T2-weighted imaging with region of interest quantitation of the acquired signal intensity. Subsequently, hepatocellular carcinoma (HCC) cells encapsulated in an agarose gel matrix were subjected to 10 V of electrolytic ablation for variable lengths of time with and without concurrent T2-weighted MR imaging. Cellular death was confirmed by a fluorescent reporter. Finally, to confirm that real-time MR images corresponded to ablation zones, 10 V electrolytic ablations were performed followed by the addition of pH-neutralizing 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer. Analysis of MR imaging from agarose gel pH phantoms demonstrated a relationship between signal intensity and pH at the anodes and cathodes. The steep negative phase of the anode model (pH < 3.55) and global minimum of the cathode model (pH ≈ 11.62) closely approximated established cytotoxic pH levels. T2-weighted MR imaging demonstrated a strong correlation of ablation zones with regions of HCC cell death (r= 0.986; R2= 0.916; P < .0001). The addition of HEPES buffer to the hydrogel resulted in complete obliteration of MR imaging-observed ablation zones, confirming that change in pH directly caused the observed signal intensity attenuation of the ablation zone. T2-weighted MR imaging enabled the real-time detection of electrolytic ablation zones, demonstrating a strong correlation with histologic cell death.

Evaluation on the acidification damage of the external anode mortar induced by impressed current cathodic protection

Impressed current cathodic protection (ICCP) can cause acidification damage in the external anode mortar and influence its durability and service life. The caused acidification effect was only experimentally investigated in the simulated pore solution and the dissolution of hydration product during the process was not considered. In this study, the acidification damage induced by ICCP treatment was investigated in the external anode mortar. The results indicated that the applied current reduced the corrosion resistance of Ti mesh embedded in the mortar; this negative effect was more pronounced in the presence of chlorides. When the external current was applied, Ca(OH)2 content at Ti mesh/secondary mortar interface decreased, leading to a lower Ca/Si ratio and increased porosity of the mortar matrix. Based on the experiment results, the acidification damage occurred at Ti mesh/secondary mortar interface was quantitatively evaluated in terms of the electric charge quantity during the treatment.

Mechanical response of the isolated cantilever with a floating potential in steady electrostatic field

Isolated micro structure, which is not directly connected to the electric circuit, can be excited into sustainable oscillation in steady electrostatic field. However, the underlying mechanism of the electrostatically self-excited oscillation is still unclear. In this work, the mechanical response of an isolated cantilever with a floating potential in steady electrostatic field is investigated. The electrically neutral cantilever is fixed to an insulating base and placed between positive and negative parallel electrodes. When a DC bias voltage is applied to the electrodes, the cantilever is observed to bend towards the positive electrode to initiate sustainable oscillation. Considering the electrostatic force applied on the cantilever is determined by the polarity and amount of electric charge, the mechanical response of the cantilever is investigated by analyzing the charge distribution on the cantilever. To explain the starting direction of the oscillation, an indirectly grounded theory is proposed with experimental validations. The free end of the cantilever carries initial negative charge due to the equivalent capacitor between the earth and the fixed end of the cantilever. Based on the oscillation mechanism, a theoretical model is developed by analyzing the equivalent capacitance of the system. The amount of charge carried by the cantilever and the corresponding electrostatic force are quantitatively analyzed to characterize of the onset DC bias voltage. Besides, the dynamic response of the cantilever during oscillation is also investigated by looking into the transferred charge by the cantilever. The modeling and test results lead to a comprehensive understanding of the electrostatic oscillator for the application in the field of micro actuation system.

Hydrogel Microchambers Integrated with Organic Electrodes for Efficient Electrical Stimulation of Human iPSC-Derived Cardiomyocytes.

A hydrogel-based microchamber with organic electrodes for efficient electrical stimulations of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) is described. The microchamber is made from molecularly permeable, optically transparent, and electrically conductive polyvinyl alcohol (PVA) hydrogel and highly capacitive carbon electrode modified with poly(3,4-ethylenedioxythiophene) (PEDOT). Spheroids of hiPSC-CMs are cultured in microchambers, and electrically stimulated by the electrode for maturation. The large interfacial capacitance of the electrodes enables several days of electrical stimulation without generation of cytotoxic bubbles even when the electrodes are placed near the spheroids. The spheroids can be cultivated in the closed microchambers because of the permeated nutrients through the hydrogel, thus the spheroids are stably addressable and the culture medium around the sealed microchambers can be simply exchanged. Synchronized beating of the spheroids can be optically analyzed in situ, which makes it possible to selectively collect electrically responsive cells for further use. As the hydrogel is electrically conductive, the amount of electrical charge needed for maturing the spheroids can be reduced by configuring electrodes on the top and the bottom of the microchamber. The bioreactor will be useful for efficient production of matured hiPSC-CMs for regenerative medicine and drug screening.

Identification on acidification damage of external anode system induced by impressed current cathodic protection for reinforced concrete.

Impressed current cathodic protection (ICCP) was widely applied for the corrosion control of reinforced concrete. During the ICCP treatment, the anodic reactions happened on the primary anode surface may induce acidification and subsequently pH drop in the vicinity of the anode, leading to damage of the external anode mortar. In this study, the relationship between the applied current (simulating ICCP treatment) on the Ti mesh anode and pH alterations in simulated concrete pore (SCP) solution (with/without chlorides) was investigated. It was found that the applied current slightly reduced the corrosion resistance of Ti mesh; this negative effect was more pronounced in the presence of chlorides. The pH value of SCP solution near Ti mesh anode decreased when the external current was applied. The consumption rate of OH- ion was higher in the chloride-containing SCP solution. A mathematical model was proposed between the electric charge quantity (Q) and OH- concentration (cOH-) in SCP solution near Ti mesh anode. This model is a useful tool to quantitatively identify the acidification damage induced by impressed current from the perspective of pH alternation near Ti mesh anode.

Effect mechanism of dielectric‐coated electrodes on metal particle lift‐off in SF 6 gas

In order to study the influence mechanism of dielectrically coated electrode in SF6 gas under DC electric field on metal particle lift-off, experimental platform is setup and motion trajectory is recorded by high-speed camera. The experiment shows that with the increasing of SF6 gas pressures, the lift-off field of metal particle is increased and the time to reach the high-voltage electrode shortened. Instantaneous displacement of metal particle is gained by image processing and computational method of charge quantity is raised, analysing of charge quantity shows that the metal particle's charge quantity decreases. Meanwhile, theoretical analysis model of field distribution around metal particle is established, result indicates that there is an enhance of electric field between coating and metal particle and a transform of charge density distribution, which leads to a downward polarisation force for metal particle. The decreasing of the electric charge quantity and the downward polarisation force results in the increasing of the lift-off field. This article maintains that partial discharge is the charging mechanism of metal particle; the enlargement of SF6 gas pressure brings about the raise of initial electric field of partial discharge, causing the increase of downward polarisation force with higher electric field to lift-off.

A simple method of dust charge estimation using an externally applied oscillating electric field

A new estimation method on the electric charge quantity of dust particles in a complex plasma is developed. This method estimates the mean electric charge of dust particles in a measurement domain. The measurement system is simple and there is not much influence on experimental conditions of a dust phenomenon in which we are interested. The experimental result obtained with this method is compared with theoretical estimations. It is confirmed that the new method provides a quantitatively correct electric charge of dust particles.

Enhancement in the dielectrics of poly(o-toluidine)/single wall carbon nanotubes (POT/SWCNTS) polymer nanocomposites for electrical energy storage

Present study focuses on influence of carbon nanotubes in POT polymer, in order to improve performance of energy storage devices. (POT/SWCNTS) nanocomposites are synthesized by situ polymerization with different concentrations of SWCNTS. POT had long chain of qunoid and benzoined rings provide together large transport of charge along with SWNTs resulting to store large amount of electric charge. Synthesized samples are characterized by dc conductivity; UV–Vis studies, FTIR, X-ray diffraction (XRD) and dielectric techniques. Electrical conductivity enhances up to four orders with dopant concentrations. Incorporation of dopant into polymer matrix is confirmed by FTIR studies. XRD analysis revealed crystallinity of nanocomposites. Present consequences of synthesized polymer nanocomposites shows meaningful impact with changes in dielectric properties due to better dispersion of SWCNTS in polymer matrix. As results enhancements in dielectric parameters values, highlights their great potential for supercapacitors. These nanocomposites do not need any binding substance that is an important practical advantage.

Dose-response study for the highly aggressive and metastatic primary F3II mammary carcinoma under direct current.

Electrochemical treatment has been suggested as an effective alternative to local cancer therapy. Nevertheless, its effectiveness decreases when highly aggressive primary tumors are treated. The aim of this research was to understand the growth kinetics of the highly aggressive and metastatic primary F3II tumor growing in male and female BALB/c/Cenp mice under electrochemical treatment. Different amounts of electric charge (6, 9, and 18 C) were used. Two electrodes were inserted into the base, perpendicular to the tumor's long axis, keeping about 1 cm distance between them. Results have shown that the F3II tumor is highly sensitive to direct current. The overall effectiveness (complete response + partial response) of this physical agent was ≥75.0% and observed in 59.3% (16/27) of treated F3II tumors. Complete remission of treated tumors was observed in 22.2% (6/27). An unexpected result was the death of 11 direct current-treated animals (eight females and three males). It is concluded that direct current may be addressed to significantly affect highly aggressive and metastatic primary tumor growth kinetics, including the tumor complete response. Bioelectromagnetics. 39:460-475, 2018. © 2018 Wiley Periodicals, Inc.

Estimation of Battery Soc for Hybrid Electric Vehicle using Coulomb Counting Method

Abstract:The autonomy of the Battery Electric Vehicle is a key point in the development and commercialization of this kind of vehicle. The requested autonomy is directly linked to the amount of the stored and remaining energy in the battery which is the State of Charge (SOC).This paper presents battery state of charge (SOC) estimation using coulomb counting method. So, the quantity of electric charge is calculated during the battery cycle of charge and discharge and compared to the estimated value based on the battery generic model. Also, experimental results are carried out in order to validate this study.

Force and Motion Characteristics of Contamination Particles near the High Voltage End of UHVDC Insulator

It is important to reveal the relations of physical factors to deposition of contaminants on insulator. In this paper, the simulation model of high voltage end of insulator was established to study the force and motion characteristics of particles affected by electric force and airflow drag force near the ultra-high voltage direct current (UHVDC) insulator. By finite element method, the electric field was set specially to be similar to the one near practical insulator, the steady fluid field was simulated. The electric force and air drag force were loaded on the uniformly charged particles. The characteristics of the two forces on particles, the relationship between quantity of electric charge on particles and probability of particles contacting the insulator were analyzed. It was found that, near the sheds, airflow drag force on particles is significantly greater than electric force with less electric charge. As the charge multiplies, electric force increases linearly, airflow drag force grows more slowly. There is a trend that the magnitude of electric force and drag force is going to similar. Meanwhile, the probability of particles contacting the insulator is increased too. However, at a certain level of charge which has different value with different airflow velocity, the contact probability has extremum here. After exceeding the value, as the charge increasing, the contact probability decreases gradually.

Laboratory study on impulse current characteristics of clay

Lightning is recognised as one of the most detrimental natural disasters. While numerous research studies were carried out on the lightning impulse characteristics of the grounding system and the critical breakdown characteristics of soil, little attention was paid to the impulse current characteristics of soils when lightning strikes. In this study, the performance of typical soft soil in Shanghai under the action of lightning is analyzed. Different factors, including the impulse current waveforms, the front time and half peak time of impulse current, the quantity of electric charge and absorption of unit heat, have been studied by performing a series of laboratory tests. The test results show that the variation of impulse current due to lightning strike is time dependent. The higher the soil temperature, the larger the peak impulse current produced during lightning strike. The value of the front time decreases exponentially, while the value of the half peak time decreases linearly with the rise of soil temperature. Novel empirical relationships between the impulse current characteristics of soil and soil temperature are proposed, with the aim of providing useful practical references for the design of a grounding system for lightning strikes.

Memristive Behavior Based on Ba-Doped SrTiO3 Films**Supported by the National Natural Science Foundation of China under Grant No 61473177, the Research Fund for the Doctoral Program of Higher Education of China under Grant Nos 2013371812009 and 20133718110011, the Natural Science Foundation of Shandong Province under Grant No ZR2014FQ006, the China Postdoctoral Science Foundation under Grant No 2015M582114, the Shandong Postdoctoral

The Sr0.95Ba0.05TiO3 (SBT) nanometer film is prepared on the commercially available Pt/TiO2/SiO2/Si substrate by radio-frequency magnetron sputtering. The x-ray diffraction pattern and the scanning electron microscope image of the cross-sectional profile of the SBT nanometer film are depicted. The memristive mechanism is inferred. The mathematical model is calculated, where M(q) denotes the memristance depending on the quantity of electric charge, and q(t) denotes the quantity of electric charge depending on the time. The theoretical I–V characteristics of the SBT nanometer film are obtained by the mathematical model. The results show that the theoretical I–V characteristics are consistent with the measured I–V characteristics. Moreover, the mathematical model could guide the research on applications of the memristor.

Effect of corona discharge on the structure and photoluminescence properties of nanocomposites based on polypropylene (PP) and zirconium dioxide (ZrO2) nanoparticles

ABSTRACTThe influence of corona discharge on the structure and photoluminescence properties of nanocomposites based on polypropylene and zirconium dioxide nanoparticles has been studied. It is shown that after the polarization under the influence of corona discharge surface roughness of polarized sample was for 40–60 nm whereas for unpolarized compositions it was 80–120 nm, i.e. the grinding of structural element took place. It was found that, after the polarization, the intensity of the photoluminescence increases depending the concentration. In order to determine the cause of the increase in the intensity of the luminescence by TSD method the stored charge at the interface between the components of the nanocomposite was studied. It has been shown that the polarization process led to accumulation of sufficiently large amount of electric charges at the interface between the components of the nanocomposite PP + ZrO2. The intensity of the internal local field of charges was calculated, and it was found that it creates a high internal local field due to the border charges. As a result, the luminescence intensity rose after increasing the value of the polarization.

基于TLS-ESPRIT算法的雾霾影响下的绝缘子泄漏电流高频特性的分析

近年来，大气污染的日趋严重导致雾霾天气在中国频繁出现。雾霾影响中的绝缘子处于极为不利的运行状态，闪络事故发生的可能性大大增加。为研究雾霾天气对绝缘子运行造成的影响，本文模拟了燃煤和汽车尾气导致的雾霾环境，测量了在不同雾霾成分作用下绝缘子表面的泄漏电流。采用TLS-ESPRIT算法分析，比较了无污秽、清洁雾喷淋的污秽绝缘子、以硝酸盐为主和以硫酸盐为主的污雾喷淋的污秽绝缘子泄漏电流高频段的频率特性。当绝缘子表面被盐溶液污染时，泄漏电流的幅值更大。高斯拟合结果显示，以硝酸盐为主的情况的幅频特性分别在f1 = 1.318 MHz和f2 = 1.468 MHz频率处存在峰值，以硫酸盐为主的情况的幅频特性在f1 = 0.199 MHz、f2 = 0.266 MHz、f3 = 0.498 MHz、f4 = 0.603 MHz频率处存在峰值。由于离子淌度和电荷量不同，以硝酸盐为主的情况峰值频率较高，表示泄漏电流能量更大。 Fog and haze weathers appear frequently in recent years in China due to atmosphere pollution. In-sulator under fog and haze is functioning in extremely poor condition, and the possibility of flash over accident is greatly increased. In order to study the impact of fog and haze on the performance of insulator, this paper simulated a fog and haze environment caused by coal burning and automo-bile exhaust, and tested leek current under different conditions. TLS-ESPRIT is applied, and fre-quency characteristics of leakage current is compared between clean insulator, insulator with clear-fog, insulator with mainly sulfate fog and mainly nitrate fog. Leek current is increased if insu-lator is polluted by salt solution. Gaussian fitting showed that nitrate condition has peak frequency at f1 = 1.318 MHz and f2 = 1.468 MHz, while sulfate condition has peak frequency at f1 = 0.199 MHz, f2 = 0.266 MHz, f3 = 0.498 MHz, f4 = 0.603 MHz. Nitrate condition has higher peak frequency due to dif-ferences in ion mobility and quantity of electric charge.

Electrically Controllable Microparticle Synthesis and Digital Microfluidic Manipulation by Electric-Field-Induced Droplet Dispensing into Immiscible Fluids.

The dispensing of tiny droplets is a basic and crucial process in a myriad of applications, such as DNA/protein microarray, cell cultures, chemical synthesis of microparticles, and digital microfluidics. This work systematically demonstrates droplet dispensing into immiscible fluids through electric charge concentration (ECC) method. It exhibits three main modes (i.e., attaching, uniform, and bursting modes) as a function of flow rates, applied voltages, and gap distances between the nozzle and the oil surface. Through a conventional nozzle with diameter of a few millimeters, charged droplets with volumes ranging from a few μL to a few tens of nL can be uniformly dispensed into the oil chamber without reduction in nozzle size. Based on the features of the proposed method (e.g., formation of droplets with controllable polarity and amount of electric charge in water and oil system), a simple and straightforward method is developed for microparticle synthesis, including preparation of colloidosomes and fabrication of Janus microparticles with anisotropic internal structures. Finally, a combined system consisting of ECC-induced droplet dispensing and electrophoresis of charged droplet (ECD)-driven manipulation systems is constructed. This integrated platform will provide increased utility and flexibility in microfluidic applications because a charged droplet can be delivered toward the intended position by programmable electric control.

Experimental investigation on water migration mechanism of macroporous silica gel in the coupling process of moisture adsorption and electro-osmosis regeneration

Electro-osmosis regeneration (EOR) of solid desiccant is a promising alternative method for dehumidification. Macroporous silica gel (MSG) has good performance on both moisture adsorption capacity and EO effect. In this paper an experimental bench is set up to investigate the water migration character and mechanism between the air and MSG in the coupling process of moisture adsorption and EOR. Through several continuous and oft-repeated experiments under different voltages, the experimental results validate that water can be transferred to a higher relative humidity environment through MSG by EO effect. It is found that the saturated water content around the anode decreases about 1.71% and 2.76% after twice EOR processes respectively. This phenomenon means the moisture re-adsorption capacity of MSG around the anode gets weaker after EOR. Based on the experimental results, the water migration mechanism of the coupling process is analyzed. Moreover, EO effect of MSG is studied from a new perspective. The water mass induced by EO has a near linear relationship with the electric charge transport with a certain EO starting value. The coefficient between the migration water mass and quantity of electric charge is about 0.0536g/C under the experimental condition.

Effects of nonmetal (F, Si, B, and P) doping on the electronic structure and elastic properties of CeO2: A first-principles study

The electronic structure and elastic properties of pure CeO2 and the nonmetal doped system CeO2–X (X = F, Si, B, and P) were investigated using plane-wave pseudopotential method and generalized gradient approximation (GGA+U) by first-principles. The calculated lattice constant, band gaps and elasticity of pure CeO2 are in good agreement with the experimental results. F-doped CeO2 exhibits increased band gap at the Fermi level and enhanced nonmetal characteristics. Conversely, P-doped CeO2 features reduced nonmetal characteristics. Moreover, Si- and B-doped systems manifest disappearing band gap and metal characteristics. In nonmetal doped systems, the quantity of electric charge transferred by atom decreases, covalent binding is enhanced, and covalent bond length shortens. After nonmetal doping, the system presents mechanical stability and decreased elastic constants (C11, C12, and C44) and elastic moduli (B, G, and E). Si, B, and P doping enhances the ductility of CeO2 and the elastic anisotropy of the system. Furthermore, F doping slightly reduces the ductility but enhances the elastic isotropy of the system.

Photoinduced enhancement of a triboelectric nanogenerator based on an organolead halide perovskite

We report a methylammonium lead triiodide (MAPbI3) perovskite-based photoenhanced triboelectric nanogenerator (TENG).