Measurement Of Electric Charge Research Articles

Numerical investigation of electric charge measurement by PWP method at solid and liquid interfaces

When a liquid contacts a solid, physicochemical reactions form an electrical double layer (EDL) at the interface. Understanding the EDL is crucial to prevent electrical device failures, but few experimental methods can access this charge distribution. Recently, the pressure wave propagation (PWP) method has been explored. This paper presents simulations of current generated by a pressure wave through the EDL using the finite difference time domain (FDTD) method. A parametric study investigates the effects of EDL parameters and stimulus properties on the signal. Simulations with EDL data obtained experimentally for both conductive and dielectric liquids are carried out.

Measurement of Electric Charge in a Charged Hydroxyapatite Dielectric Using Pendant Drop.

A simple noninvasive measurement method which allows one to determine the trapped charge in a biocompatible hydroxyapatite dielectric is developed. The hydroxyapatite samples are charged by electron beam with energy 30 keV and total irradiated charge ranging from 2 × 10-9 C to 2 × 10-7 C. The value of the trapped charge is determined by analyzing the shape change of a liquid droplet hanging from a needle in proximity of the charged sample surface. The shape change of the pendant drop in the field of gravity is commonly utilized in the measurements of the surface free tension (SFT) of liquids. The external electric field leads to a further modification of the droplet shape and to an effective change of the SFT. The change of the SFT as a function of distance between the droplet and sample and the critical distance at which the droplet detaches from the needle are measured for various values of the irradiated charge. These two quantities are also derived theoretically by considering the trapped charge as a single fitting parameter. We can thus determine the trapped charge in two independent noninvasive ways. It is noteworthy that our method is easily implementable into the standard pendant drop setups. As a practical application of the method, a long-term charge stability of the charged hydroxyapatite is demonstrated, thus paving the way toward quantitative studies of its bioactivity in dependence on the value of the trapped charge.

Towards plasma jet controlled charging of a dielectric target at grounded, biased, and floating potential

Electric field and surface charge measurements are presented to understand the dynamics in the plasma–surface interaction of a plasma jet and a dielectric surface. The ITO coated backside of the dielectric allowed to impose a DC bias and thus compare the influence of a grounded, biased and floating potential. When imposing a controlled potential at the back of the target, the periodical charging is directly dependent on the pulse length, irrespective of that control potential. This is because the plasma plume is sustained throughout the pulse. When uncontrolled and thus with a floating potential surface, charge accumulation and potential build-up prevents a sustained plasma plume. An imposed DC bias also leads to a continuous surface charge to be present accumulated on the plasma side to counteract the bias. This can lead to much higher electric fields (55 kV/cm) and surface charge (200 nC/cm^2) than observed previously. When the plasma jet is turned off, the continuous surface charge decreased to half its value in 25 ms. These results have implications for surface treatment applications.

Real-Time SoC Estimation for Li-Ion Batteries using Kalman Filter based on SBC Raspberry-Pi

Measurement of electric charge on the battery in real-time cannot be separated from external noise and disturbances such as temperature and interference. An optimal State of Charge (SoC) estimator model is needed to make the estimation more accurate. To obtain the model, the battery was tested under room temperature conditions and at a temperature of 40oC to obtain a second-order RC model for the Li-Ion battery used. Based on the test data obtained, the data will be tested first using the Kalman Filter method to get an estimate of the State of Charge (SoC). Tests were carried out using MATLAB software. After the method was tested, the online SoC Estimator design began using the Raspberry Pi Single Board Computer (SBC). After that, the estimator will be tested first using data from offline measurements and then used in real-time (online) SoC estimation measurements. The Voc before the battery discharge test was 13.16 V and after the test, the measured Voc was 11.58 V. During the discharge the Voc was reduced by 1.58 V. While the discharge data from the battery manufacturer showed the reduced Voc during the discharge was 1.2V.

Real-Time SoC Estimation for Li-Ion Batteries using Kalman Filter based on SBC Raspberry-Pi

Measurement of electric charge on the battery in real-time cannot be separated from external noise and disturbances such as temperature and interference. An optimal State of Charge (SoC) estimator model is needed to make the estimation more accurate. To obtain the model, the battery was tested under room temperature conditions and at a temperature of 40oC to obtain a second-order RC model for the Li-Ion battery used. Based on the test data obtained, the data will be tested first using the Kalman Filter method to get an estimate of the State of Charge (SoC). Tests were carried out using MATLAB software. After the method was tested, the online SoC Estimator design began using the Raspberry Pi Single Board Computer (SBC). After that, the estimator will be tested first using data from offline measurements and then used in real-time (online) SoC estimation measurements. The Voc before the battery discharge test was 13.16 V and after the test, the measured Voc was 11.58 V. During the discharge the Voc was reduced by 1.58 V. While the discharge data from the battery manufacturer showed the reduced Voc during the discharge was 1.2V.

Мікрокулонометр – вимірювач електричних зарядів

The most difficult problem in the laboratory practice of the educational process for the demonstration of electrostatics and electromagnetism is the measurement of electric charges on the surface of bodies and in the airspace of the environment. The fundamental property of electric charges is determined by their type, which are conditionally called positive and negative, they are attracted or repelled, have an electromagnetic interaction. Characterized by an elementary charge i.e. the smallest value of electric charge, regardless of type. The electric charge can take only a discrete value proportional to the smallest charge, which can only be expressed as an integer regardless of the type of charge. Depending on the surface on which they are located, they can have different concentrations, which can be described by linear, surface or bulk density. Electric charges are subject to the law of conservation of charges – the sum of charges in an isolated system is constant. Measurement of electric charges is complex, devices – galvanometers and electroscopes, which are used for this purpose, require certain conditions that are not always convenient to use, do not provide the necessary accuracy of measurement. Methods and devices using the circuitry of a microcoulometer for measuring electric charges in electrostatics and electromagnetism, which is built on a modern element base with the use of operational amplifiers and microcontrollers, are proposed.

Electro-exchange in the system of the condensed dispersed phase and a heated titanium particle

The results of studies of titanium particles with diameters from 10 to 100 microns heated above the melting point in air are presented. A diagram and photographs of an experimental facility are shown. It consists of a generator of heated titanium particles, a temperature measurement unit, which includes a photoelectric temperature sensor for moving particles, an electric charge measurement unit, consisting of vertical flat parallel charged metal plates, and a unit for measuring particle velocity. It has been experimentally established that around such particles when they move in air a condensed dispersed phase – c-phase – consisting of titanium oxides nanoparticles is formed. The results of electron microscopy studies of the condensed dispersed phase has shown that the particle size of the condensed dispersed phase lies in the range of 5 - 100 nm and depends on the initial conditions. Theoretical calculations that determine the electro-exchange in the system of a heated spherical particle and the condensed dispersed phase surrounding it has shown the agreement with the experimental data within the measurement error, and the particle charge was on the order of hundreds of thousands – a million of electron charges. A theoretical study of the kinetics of thermionic charging of titanium particles has shown that the accumulation time of 95% of the equilibrium particle charge at temperatures of 3000–2200 K was 14 ns – 33 μs, respectively. At the temperature of 2000 K, the accumulation time of 85% of the equilibrium charge was 240 μs. At the temperature of 1400 K, the accumulation time of 91% of the equilibrium charge of the same particle was 610 μs. Estimates have shown that during a charge relaxation time for a titanium particle at temperatures greater than 1400 K the time of charging practically does not change. This allows us to consider the process of thermionic charging of particles under these conditions as quasistationary. The results can be used in studies of the processes of electro-exchange in aerodispersive systems at high temperatures. The developed model of thermionic charging of particles allows its further use to simulate the behavior of the c-phase around heated particles, as well as for other purposes. The obtained results show a satisfactory agreement between the experimental and calculated values of the charge.

System electro-neutralizer of agrochemicals contained in food and water samples through electrons trap

Abstract This study presents a system to electro-neutralize agrochemicals in food and water samples based on the properties of a controlled electron trap, the related apparatus is protected under patent application (WO/2018/090110; INPI: BR 10 2016 0268486) / (PCT / BR 2017/050115). The efficacy of the system was verified as to the type, quantity, surface tension charge, temperature, pH and static energy loading of the electrolyte for both solid and liquid samples. It also took into consideration the retention and accumulation measurement of electric charges, verification of electrical potential differences and also accumulation by applying pulsed high voltage in according to the Daniell Cell method. The proposed technology is able to provide the electron-neutralization of acidic and alkaline chemicals and their toxic byproducts by modifying the pH of the liquid or solid medium. This is justified by the action of the electron trap using different polarities and electrodes in the range of 8 to 100 kV.

Precision measurement of few charges in cavity optoelectromechanical system

An efficient scheme for detecting charge numbers of nearby charged body is presented in the cavity optoelectromechanical system. This is realized by means of the sensitive relationship between the charge number and the measured photon number. The proposed scheme is feasible with experimentally accessible values and is applicable to precision measurement of electrical charge.

Non-contact measurement of electric charges on water surface supplied with plasma

Transferred charges in water associated with discharges are measured using an electrostatic voltmeter, without any physical contact between the electrode and water. Unlike the method that uses a voltage probe, this method allows for the estimation of charges in water under an electrically floating state. In this paper we introduce a needle-water discharge system which uses the needle electrode over the ultrapure water surface. First, we evaluated our needle-water discharge system with various applied voltages by analysing the current waveforms. Thereafter, by synchronising an oscilloscope and a data logger, the surface potential and discharge waveforms were obtained simultaneously at different time scales. It was found that the measured surface potential of water is proportional to the transferred charges. Two types of materials, namely, glass and polystyrene, were used as the water container material, and it was observed that when the glass container is used, the characteristic decay time of the potential is 2.02 s, which is much shorter than in the case of a polystyrene container. This is due to a much lower surface resistivity of polystyrene. This finding is important because when a DC voltage is applied to the needle electrode, discharging is terminated due to the charges accumulated in water. The termination tendency is, however, varies based on the container material used, even when the same voltage conditions are applied.

Precision measurement of electrical charge in a hybrid optomechanical system with Michelson interferometer

In this work, we present a scheme to measure electrical charge by combining a cavity optomechanical system with Michelson interferometer. The optomechanical cavity with a charged movable mirror is placed in one arm of a Michelson interferometer, in which the cavity length is modified due to the Coulomb force between the charged moveable mirror with the unknown charge and the charged body with the known charge, leading to a change in the output of the cavity mode. In addition, a perfectly reflecting mirror is rigidly fixed in the other arm. The unknown electrical charge can be measured by the difference of output intensities in both arms of the Michelson interferometer. The theoretical derivation and the numerical simulation indicate our scheme is more sensitive to the external Coulomb force and the precision of the scheme can reach unity charge, due to resorting to the Michelson interferometer. Besides, the effect of temperature on the sensitivity of electrical charge detector is also discussed.

Measurement of total electric charge of submicrometer particles using a DBD charger coupled with a capacitive sensor

The objective of this experimental research work is to evaluate the efficiency of a capacitive system for particles charge measurement. The obtained results are used to assess the performance of an aerosol DBD charger based on the particle losses. The charge measurement system consists of a sensitive electrometer that determines the total charge of the particles flowing through a capacitive sensor, and a DBD charger that is used to charge particles at elevated levels. The results are compared to that obtained using an Electrical Low Pressure Impactor (ELPI+). Experimental results show similar behavior of both detection instruments employed in this study. In particular, equivalent trend, order of magnitude and polarity of total charge are obtained for different status of the DBD charger (different frequency, voltage and geometry).

Generation and enhancement of sum sideband in a quadratically coupled optomechanical system with parametric interactions.

We investigate theoretically the generation and enhancement of sum sideband in a quadratically coupled optomechanical system with parametric interactions. It is shown that the generation of frequency components at the sum sideband stems from the nonlinear optomechanical interactions via two-phonon processes in the quadratically coupled optomechanical system, while an optical parametric amplifier (OPA) inside the system can considerably improve the sum sideband generation (SSG). The dependence of SSG on the system parameters, including the power of the control field, the frequency detuning of the probe fields and the nonlinear gain of OPA are analyzed in detail. Our analytic calculation indicates that the SSG can be obtained even under weak driven fields and greatly enhanced via meeting the matching conditions. The effect of SSG may have potential applications for achieving measurement of electric charge (or other weak forces) with higher precision and on-chip manipulation of light propagation.

Measurement of Electrical Charges for the Control of the Air External Environment

The concentration of charged parts of the airspace (atmosphere) affects air quality and human health. This is due to the need to control the state of airspace for compliance with sanitary and hygiene standards. Measurement of electrical charges in the airspace of the environment has its own characteristics and differs from the measurement of those charges induced on the surface of materials of different nature. Requires specific sensors, depending on which environment parameters to be evaluated: volumetric, plane or other. Also important is the mode of measurement: permanent, single or reshort-term. These features and determine the method of measuring electric charges in the atmosphere of the environment. This article presents one of the methods of continuous measurement of charged parts of airspace, and also shows how the parameters of the sensor can specify the range of measurement of the concentration of electrical charges in the airspace of the environment.

Holographic deflection imaging measurement of electric charge on aerosol particles

We propose a simple noninvasive technique called holographic deflection imaging (HDI) to measure electric charge on individual aerosol particles. Particles in many flows such as atmospheric turbulence can carry electric charges, which add forces that compete with turbulence and affect particle dynamics. To measure particle charges, we devised a novel technique for polydispersed particles with bipolar charge distributions. The technique uses common optical hardware and a novel particle sizing algorithm for polydispersed size distributions. A charged particle sample is introduced into a vertical channel air flow and a horizontal electric field. For each particle, In-line digital holography is used to simultaneously track particle positions over successive holograms and decode size information from hologram interference fringes. This enables measurement of the electric-force-induced horizontal component of terminal velocity and the particle size. From velocity and size, particle charge is calculated using a force balance, assuming Stokes drag on spherical particles. Two experiments were conducted, one to validate HDI measurements of a bipolarly charged particle sample against an electrometer, and the other to demonstrate particle size effect on triboelectric charging of aerosols in a fan-driven isotropic turbulence chamber. The HDI setup was configured for each experiment, and measurement uncertainty was estimated. Experiment 1 found good agreement (< 5%) in mean charge between measurements by HDI and the electrometer. Experiment 2 found nearly symmetric bipolar charge distributions, which broadened with increasing particle surface area, as expected for triboelectric charging by the symmetrically installed fans.

Novel concept for a neutron electric charge measurement using a Talbot-Lau interferometer at a pulsed source

A concept to measure the neutron electric charge is presented which employs a precision Talbot-Lau interferometer in a high-intensity pulsed neutron beam. It is demonstrated that the sensitivity for a neutron charge measurement can be improved by up to two orders of magnitude compared to the current best direct experimental limit.

Adsorption of hydrogen and hydrogen–containing gases on Pd– and Ag–single atoms doped on anatase TiO2 (1 0 1) surfaces and their sensing performance

The Pd– and Ag–doped anatase TiO2 (1 0 1) surfaces were investigated and the binding energies of single atom of Pd (−2.15 eV) and Ag (−2.38 eV) on the anatase (1 0 1) surfaces, respectively denoted as Pd/TiO2 and Ag/TiO2, were obtained. Binding sites for Pd and Ag atoms toward the TiO2 surface atoms are three atoms (Ti5C and two O2C atoms) and two O2C atoms of the TiO2 (1 0 1) surface, respectively. Due to adsorptions of H2 and hydrogen–containing (H2O, NH3, and CH4) gases on the Pd/TiO2 and Ag/TiO2, adsorption abilities on the Pd/TiO2 and Ag/TiO2 are in decreasing orders: NH3 > H2O > H2 > CH4 and NH3 > H2O > CH4 > H2, respectively. Mulliken–charge transfers from the Pd and Ag atoms to adsorption atoms of the anatase TiO2 (1 0 1) surface and the adsorption of hydrogen and hydrogen–containing gases to the Pd/TiO2 and Ag/TiO2 were observed. The Pd/TiO2 and/or Ag/TiO2 have high potentials to be NH3 sensing materials based on the electric conductivity measurement. The Pd/TiO2 has high potential to be CH4 sensing device based on the electric conductivity and surface charge measurements.

Highly Sensitive Optical Detector for Precision Measurement of Coulomb Coupling Strength Based on a Double-Oscillator Optomechanical System

An optomechanical system combining a Coulomb interaction degree of freedom provides a unique platform for precision measurement of electrical charges via the optomechanically induced transparency. A new property of a second-order sideband in a double-oscillator optomechanical system is investigated beyond the conventional linearized description of optomechanical interaction. The results show that the single-second-order sideband will split into the double-second-order sideband under a weak driving field, and the separation of the split second-order sideband shows a strong dependence on the Coulomb coupling strength. Based on the current experimental conditions, such a Coulomb-interaction-induced split of the second-order sideband may enable an all-optical sensor for precision measurement of the Coulomb coupling strength with lower power.

Modification of surface characteristic and tribo-electric properties of polymers by DBD plasma in atmospheric air

The aim of this paper is to quantify the effects of dielectric barrier discharge (DBD) exposure on the physico-chemical and tribo-electric properties of polymers. The study was conducted in atmospheric air on polypropylene, polyethylene and polyvinyl-chloride. These three types of polymers are widely used in industry. The polymers were characterized by means of an optical profilometer, a fourier-transform infrared (FTIR) spectrometer and an electric charge measurement system. The latter is composed of a Faraday pail connected to an electrometer. The profilometer analyses showed that the DBD plasma treatment has increased the surface roughness of the three polymers. FTIR revealed that oxygen atoms and polar groups were grafted on their surfaces, thereby conferring them a hydrophilic character. The short (2 sec) DBD plasma treatment has considerably improved the electrostatic charge acquired by the polymers during electrostatic tribo-charging, while longer exposures conferred the polymer anti-static properties and decreased its tribo-charging capability. The correlation between the results of the physico-chemical analyses and the tribo-electric behavior has been discussed.

Highly sensitive optical sensor for precision measurement of electrical charges based on optomechanically induced difference-sideband generation.

Difference-sideband generation in an optomechanical system coupled to a charged object is investigated beyond the conventional linearized description of optomechanical interactions. An exponential decay law for difference-sideband generation in the presence of electric interaction is identified which exhibits more sensitivity to electrical charges than the conventional linearized effects. Using the exact same parameters with previous work based on the linearized dynamics of the optomechanical interactions, we show that optomechanically induced difference-sideband generation may enable an all-optical sensor for precision measurement of electrical charges with higher precision and lower power. The proposed mechanism is especially suited for on-chip optomechanical devices, where nonlinear optomechanical interaction in the weak coupling regime is within current experimental reach.