Electric Current Values Research Articles

Measurement of Void Fraction in a Two-Phase Flow for Unstable Liquid Conductivity in Multi-Electrode Voltage–Current System Using a Normalization Equation With Two Correction Parameters

The normalization equation with two correction parameters ${\beta }$ and ${\gamma }$ is proposed to estimate the void fraction of liquid–gas flow under the condition of unstable liquid conductivity using a multi-electrode voltage–current (me-VC) system. The variation of electrical current value due to change in liquid conductivity of liquid phase is corrected using parameter ${\beta }$ . While ${\gamma }$ is the gradient correction parameter, which corrects the different variation rate of normalized electrical current affected by liquid conductivity and the void fraction ${\alpha }$ in liquid–gas flow. A lookup table for ${\beta }$ and ${\gamma }$ is created based on the normalized electrical current obtained at four liquid conductivity and six void fraction conditions. From the experimental results, the proposed normalization equation with ${\beta }$ and ${\gamma }$ shows better performance in estimating void fraction than conventional normalization equation when the conductivity of liquid in liquid–gas flow is unstable. Through the results, it is found that the proposed normalization equation successfully measures the void fraction ${\alpha }$ within a 5% error rate.

Simulation of Distributed Current Sensor Based on Optical Fiber Deformation

Due to the development of automation and control systems, methods and devices for measuring of electric current large values are of great interest. The aim of the work was to develop a schematic diagram of a distributed current strength sensor based on the Brillouin optical frequency domain analysis; to create a mathematical model of the sensor to demonstrate its work and to calculate the basic parameters of the sensor. To provide the measurement optical fiber with conductive coating is used. Between the current bus, where current is measured, and conductive coating the Ampere force arises. Strain occurs in optical fiber due to this force. Stimulated Brillouin scattering has the strain dependent characteristic frequency. Shift of the characteristic frequency allows to measure current in the bus. To measure the characteristic frequency and the location of its shift Brillouin optical frequency domain analysis is used.The mathematical model of sensor operation based on tree-wave model of stimulated Brillouin scattering is demonstrated. This model allows calculating intensity of optical signal in the fiber in dependence of characteristic frequency shift. Brillouin optical frequency domain analysis uses inverse Fourier transform to obtain pulse response.A schematic diagram of a distributed current sensor based on the method of Brillouin optical frequency domain analysis is presented. An a priori estimate of parameters of the measuring system was carried out on the basis of the mathematical model of stimulated Brillouing scattering in an optical fiber. The spatial resolution of the sensor when determining the length and location of fiber sections was 0.06 m. The resolution of the sensor was 0.22 kA, the maximum value of the current strength was 25 kA. Dependence of the sensor operation at different powers of the laser used was investigated. The refractive index change influence on the result of measurements was estimated.

Tribological Behavior of a Contact Pin on Cylinder CuSn7 Bronze Rubbing Against 20MnCr5 Steel in Dry Sliding with Electrical Current

The tribological behavior of CuSn7 Bronze and Steel 20MnCr5 couple was studied as a function of mechanical and electrical parameters and the contact geometry (pin on cylinder) under ambient environment. To do this, a pin on cylinder tribometer (the test machine is a kind of pin-on-slip ring) was used. Experimental results show that these parameters have a significant effect on the friction and on the wear. Indeed, the load has a significant influence on the tribological behavior of the couple both with and without electrical current. In the other hand, the friction coefficient and wear of the pin against the cylinder decreases especially at high values of electrical current. Moreover, the observed wear mechanisms are: adhesion, abrasion, oxidation, arc erosion and plastic deformation. At high applied electrical current and loads, the main wear mechanism is the arc erosion and severe plastic deformation. The discussion of the obtained results is based on examination of the worn surfaces and analysis performed on interfacial phenomena observed during the friction process.

Numerical study of electro-vortex flow in long cylinder with localized current supply

Numerical simulations of the electrovortex flow (EVF) of the GaSnZn alloy in a closed cylindrical volume are performed. The electric current is applied with two localized opposed electrodes on the cylinder side wall. It is shown that in the entire considered range of electric current values from 50 to 1000 A the EVF arises in a cylinder, in a form of the two-toroidal flow. The flow intensity increases with increasing current values and its maximum intensity is 12 cm/s (at 1000 A). Even at the lowest electric current value of 50 A, a non-stationary behavior of EVF is observed. However, the two-toroidal flow pattern is present in all considered regimes. It is shown that with increasing current the velocity pulsations in the near-electrode region have a frequency up to 0.26 Hz.

Thermally induced vibration and strength failure analysis of thermoelectric generators

Thermal vibration and the strength failure of a thermoelectric generator (TEG) subjected to the time-dependent heat flux is discussed in this paper. The heat flux is considered as varying along the circumference of the circular cross section of the TEG, which consists a series of n-type and p-type thermoelectric elements. Vibrations that are parallel and perpendicular to the gravity direction are analyzed, respectively. Analytical and simplified solutions of the vibration deflections of the TEG are given. The maximum principal stress in the TEG is derived analytically. Based on the criterion of maximum principal stress, the envelop curve of heat flux and electric current density corresponding to failure strength of the TEG is obtained. It is found that the vibration deflection is proportional to the heat flux and the value of square electric current. The thermal vibration reduces the output power of the TEG but it only has effect on the output power in a very short time. A bigger damping ration results in a smaller maximum principal stress. The maximum principal stress does not vary with the damping ratio if the length of TEG is small. The critical heat flux and electric current density increase and finally trend to constants with damping ratio.

Role of Clathrin Protein to Increase Electric Current on Dye-Sensitized Solar Cell (DSSC) Based Natural Dyes

Dye-Sensitized Solar Cell (DSSC) has the cost of fabrication is relatively cheap, easy to produce, work on the area of the visible light and environmentally friendly. The shortage of DSSC, namely the efficiency is still low compared with solar cells of silicon. In this study, have been successfully fabricated DSSC with clathrin protein deposited. The method used in this research is to deposit clathrin protein in porous TiO2 semiconductors with a concentration of 0%, 25%, 50%, and 75%. Tests carried out on the DSSC that has been made current testing electricity using a solar simulator to determine the changes in electrical current that occur in DSSC. The conclusion from this research is that with increasing concentration of the addition of the clathrin protein in the DSSC leads to an increase in the electric current generated by DSSC. From the results of testing using a solar simulator obtained the value of electric current is the highest, namely 5.247 mA with the addition of the concentration of the clathrin protein by 75%.

A measurement method for determining the correlation between the amount of haemolysis and the electric current in low‐temperature plasma treatment

We have developed a low‐temperature plasma apparatus as a surgical device for haemostasis. A quantitative measurement method and system that analyses the relationship between the properties of low‐temperature plasma and blood components are necessary to evaluate the performance and safety of plasma apparatuses. In a previous study, we revealed that low‐temperature plasma haemolyses erythrocytes, and the released haemoglobin contribute to clot formation; haemolysis by low‐temperature plasma occurs when the value of the current originating from low‐temperature plasma exceeds a certain threshold. In the current study, we examined the correlation between the haemoglobin concentration and the electric current value through experiments using our improved measurement system. We propose a method to control the haemolysis effect by adjusting the plasma current value.

PULSED ELECTROMAGNETIC GAS VALVES FOR HIGH-CURRENT PLASMA ACCELERATORS

The paper describes the design features of a gas valve for the axial (parallel to the axis of the accelerator) working gas supply into the accelerator channel. The results of gas-dynamic studies of the injectors are presented. The amount of the working gas inlet was investigated as a function of gas pressure under the blocking valve element. A strong dependence of the amount of the injected working gas on the electric current value in the control coil was found.

Solar photovoltaic-battery system as a green energy for driven electrochemical wastewater treatment technologies: Application to elimination of Brilliant Blue FCF dye solution

This study investigate the feasibility of using solar photovoltaic cell (PV) – battery system as a renewable energy source for driven electrochemical treatment of acidic solution of food colorant Brilliant Blue FCF (E133) dye using boron-doped diamond (BDD) anode and carbon-felt cathode. The average solar irradiation intensity of over 20,000 kJ m−2 day‒1 was recorded and the PV cells produced more than 10 A current intensity for 8.5–9 h a day, which was sufficient for completely charge two 12 V batteries during the day. Irrespective of slight fluctuation of solar irradiation, constant electric current values (100–500 mA) were able to selected for the electrooxidation with H2O2 (EO-H2O2) and EF treatment of E133 solution. Complete decolorization and mineralization of the E133 solutions was achieved with either process at higher current, whereas only total color removal was obtained at lower current with excellent COD removal. The initial N in the E133 molecule was recovered in the treated solutions mainly as NH4+ along with significant proportion of NO3‒, whereas SO32‒ in the molecule was released into the solution as SO42‒ without detecting SO32‒. The solar PV-battery system is a suitable green energy source for efficient electrochemical treatment of organic polluted wastewater.

Antibacterial TiCu/TiCuN Multilayer Films with Good Corrosion Resistance Deposited by Axial Magnetic Field-Enhanced Arc Ion Plating.

In order to develop a novel kind of antibacterial Cu-containing TiN film with good corrosion resistance, impressive mechanical properties, and low cytotoxicity, three differently designed multilayer films of TiCu/TiCuN multilayer (M1, M2, M3) were deposited on the surface of 316L stainless steel surface using the axial magnetic field-enhanced arc ion plating (AMFE-ARP) method, in which the interlayer of TiCu was first introduced for Cu-containing TiN film in order to improve comprehensive properties, especially the corrosion resistance of the film. The performance of the TiCu/TiCuN multilayer films was compared with that of the two single layers, TiN and TiCuN, which were deposited by the same method and the same total deposition time. The results indicated that the TiCu/TiCuN multilayer film of M2 revealed the best comprehensive corrosion resistance with low electric current values, high pitting potential, and high polarization resistance due to the proper thickness of TiCu interlayers and larger number of TiCu/TiCuN bilayers. In addition, the TiCu/TiCuN multilayer film of M2 also possesses comparable mechanical properties, excellent antibacterial and antibiofilm abilities, as well as good biocompatibility. Consequently, the antibacterial TiCu/TiCuN multilayer films with good corrosion resistance deposited by using the axial magnetic field-enhanced arc ion plating (AMFE-ARP) method are promising for application in biomedical antibacterial film for implants.

MONITORING OF ELECTRICAL SYSTEM USING INTERNET OF THINGS WITH SMART CURRENT ELECTRIC SENSORS

Electricity is one of the most important human needs. In the presence of electricity it can facilitate human work. But it should be noted that too large and uncontrolled electricity use will be wasteful and get high costs. The problem is that electricity is not monitored accurately, easily and efficiently. This study aims to design an electric current monitoring device with an IoT system. IoT is a concept with the ability to transfer data by network, no need humans to humans or humans to PCs. In this concept, the SCT 013-000 electric current sensor is connected to the load, it will be show electric current value in the LCD, if the electric current which is determined exceeds the capacity, Wemos D1 including Wifi ESP 8266 will be sending a notification to the telegram. The system has been implemented with ironing load for 3.29%, the dispenser load is 0.20% and Magicom's get load for 1.07%. The delay time also has been implemented in the relay for 1.50 second when relay is on and 0.78 second when relay is off. When the notification send to the telegram also have a delay for 6.2 second. So, monitoring of electrical system using internet of things with smart current electric sensors has been done.

The effect of welded joint properties on the surface characteristics of laser-welded 2205 duplex stainless steel

Welded joints of poor welding surface quality are sensitive to stress concentrations, affecting both the tensile strength of workpieces and the fluidity of liquids and gases in pressure and liquid containers. Orthogonal experiments involving the laser welding of 1-mm-thick duplex stainless steel sheets were conducted using different electric current, pulse width and frequency values in order to analyse the effect of welding properties on the surface characteristics of the welded joints. Rapid judgement regarding the welded joint properties was made based on the observed welding surface quality. The results show that an even phase proportion and grain refinement are not necessarily guaranteed to provide good welding surface quality. A satisfactory welding surface quality characterised by a smaller spot pitch or spot pitch difference, smaller weld width, reduced surface roughness and valley depth of surface waviness implies better welded joint mechanical characteristics and a more even microstructure. The specimen with the most suitable welding parameters and the greatest heat input can reach the lowest volume fraction of ferrite phase of 42.5% and the highest tensile strength of 848 MPa, and its surface quality is the best.

Comparison of light emitting capacitors with textured and polished silicon substrates towards the understanding of the emission mechanisms

We experimentally compare the optical and electrical characteristics of Light Emitting Capacitors (LECs) using textured and polished silicon surface. The goal of this work is focused to investigate the influence of the roughening of the surface of the silicon substrates in the electro-optical properties of LECs fabricated with off-stoichiometric silicon oxide (SiOx). The textured surface is produced by reactive ion etching using Ar and SF6 as ion sources. It exhibits an average roughness of 4.0 ± 0.2 nm, with a spike density of 3.7 ± 1.8 × 1010 cm−2. The SiOx is deposited by low-pressure chemical vapor deposition on polished and textured substrates. The turn-on electric field of LECs using textured substrate is reduced from 8.5 MV/cm to 7.0 MV/cm, and the power conversion is improved 4.1 times compared with LECs with polished substrate. Furthermore, in LECs fabricated over textured substrates, the electrical current value increases at low voltages and once it reaches the high current regime, this value remains constant. Then, the spikes on the silicon substrate improve carrier injection towards the SiOx at low electric fields, causing more trapping of electrons in the SiOx and enhancing the electroluminescence response at high electric fields. An explanation of the enhanced electro-emission mechanisms is given. Also, a figure of merit that allows the comparison with LECs with different technological characteristics is proposed.

Load Disaggregation via Pattern Recognition: A Feasibility Study of a Novel Method in Residential Building

In response to the need to improve energy-saving processes in older buildings, especially residential ones, this paper describes the potential of a novel method of disaggregating loads in light of the load patterns of household appliances determined in residential buildings. Experiments were designed to be applicable to general residential buildings and four types of commonly used appliances were selected to verify the method. The method assumes that loads are disaggregated and measured by a single primary meter. Following the metering of household appliances and an analysis of the usage patterns of each type, values of electric current were entered into a Hidden Markov Model (HMM) to formulate predictions. Thereafter, the HMM repeatedly performed to output the predicted data close to the measured data, while errors between predicted and the measured data were evaluated to determine whether they met tolerance. When the method was examined for 4 days, matching rates in accordance with the load disaggregation outcomes of the household appliances (i.e., laptop, refrigerator, TV, and microwave) were 0.994, 0.992, 0.982, and 0.988, respectively. The proposed method can provide insights into how and where within such buildings energy is consumed. As a result, effective and systematic energy saving measures can be derived even in buildings in which monitoring sensors and measurement equipment are not installed.

Measurement of Anode Arc Attachment Movement in DC Arc Plasma Torch at Atmospheric Pressure

Direct current (DC) arc plasma torches are widely used in various industrial applications. Studying processes in their anode area helps to extend their lifetime, and stabilize the plasma flow for plasma applications. This paper reports detailed observations of the fast movement (above 100 m/s) of the anode arc attachment in a hybrid water-argon DC arc plasma torch with an external anode. We measured a mean electrical conductivity of a plasma volume above the anode and found a relation between the attachment movement and the anode erosion. Further, we measured average attachment speed, the average period of the restrike process and the average distances travelled by the attachment under different experimental conditions such as different values of the arc electric current, argon flow rate and different anode configurations. For our measurements, we used a high-speed camera and a high-voltage probe. Our results are in agreement with a model of plasma generated by a hybrid plasma torch and with spectroscopy measurements. The results describe the movement of the anode arc attachment in detail and provide experimental data on average plasma electrical conductivity in hot anode areas. Both the measurements of the mean electrical conductivity and the procedure for quantitative comparisons of anode erosion can be used also in water plasma torches and theoretically also in gas plasma torches.

Linear correlation between pH value of stimulated beef and electrical current intensity

ABSTRACTThe aim of the present study was to determine mathematical relationships between pH changes in beef 24 h post-slaughter and changes in the intensity of electrical current flowing through bull and heifer carcasses during high-voltage electrical stimulation. The electrical stimulation was applied 40 min postmortem for 120 s. The pH values of m. longissimus thoracis et lumborum were analyzed in the function of electrical current intensity changes and its change during electrical stimulation. Mathematical linear correlations of the y = ax ± b type were demonstrated between pH values at 2, 6, and 24 h postmortem and the initial (Ii) and ultimate (Iu) electrical current intensity values, the difference between them and the initial pH values determined before electrical stimulation. High multiple correlation coefficients (R2 = 0.416, α ≤ 0.001) between Iu and pH values 24 h post-slaughter enabled concluding that there is a possibility to predict a pH value of stimulated carcass with high accuracy, and thus also beef quality, based merely on the ultimate electrical current intensity values.

Pseudomonas aeruginosa Membrane Capacitive Characteristic and Frequency Relative Power Consumptions

Introduction: Study the electrical properties of microorganisms is a great importance to control their hostile effect especially, some organisms such as Pseudomonas aeruginosa (PA), when infection with this type of bacteria causes high percentage of patients' mortality in hospitals. Depending on interaction differences between bacterial cell with electrical current and human cell with electrical current, bactericidal effect may be achieved. This study observed the behavior of PA when it was exposed to different frequency values of clinically safe alternative current to prove the capacitive characteristic of bacterial membrane and find difference between powers consumed by bacterial sample for each frequency value. Method: PA isolates were activated by using Trypticase Soya Broth (TSB), 10 percent of 3.24 × 108 cfu/ml of PA mixed with agarose and poured in petri dish to solidify at room temperature. Electrical current of 20 Vp-p applied to the sample via movable Nichrome electrodes or built in Nickel electrodes, 2 cm apart between anode and cathode electrodes, electrical current measured and recorded during stimulation using multi-function voltmeter. Results: The results proved that in general when the frequency of electrical current increased (analysis of variance (ANOVA) P>0.05), the current pass through PA samples increased relatively which refer to decrease in samples' impedance due to increase in frequency from 0.366 Hz and reach maximum at 40 KHz where it become constant until 60 KHz then began to reduced again until it reaches constant value at 120 KHz. Conclusion: Clinically accepted electrical current values of different frequencies values interact in different manner with PA samples, and the electrical current consumption by PA affected and in general increased by increasing its frequency. This study also shows that there is different impedance values to different electrical current frequencies values which prove some part of impedance affected by frequency change which prove that PA membrane has a capacitive effect.

Smart materials activation analysis on example of nickel and titanium alloys

This paper is focused on research concerning activation time of elements made of Ni-Ti alloy (55/45% vol.) The activation time is a period of time required for alloy to reach it’s austenitic transformation (Af) temperature. For examined wire it reached values up to 60 °C. Heating of NiTi wire was conducted by retaining heat. In this paper the influence of wire length and electric current power on heating time is presented. This research allows to determine the correlation between the increase of temperature and time. For given electric current values. This data is useful for effective design of SMA actuators‥

A proposal for an alternative use of prompt-Self Powered Neutron Detectors: Online spectral-deconvolution for monitoring high-intensity neutron flux in LFRs

Self-Powered Neutron Detectors (SPNDs) are currently used in reactors’ environment to sense the magnitude of neutron-fluxes, usually for spatial-distribution mapping of the fuel region as to optimize burn-up strategies. During the development of tailored instrumentation for Lead-cooled Fast Reactors, the possibility to perform online spectral deconvolution of fast neutron-fluxes was recognized. Seven geometrically similar SPNDs with different neutron-sensitive materials, have been characterized by the Monte Carlo transport code MCNPX. Thanks to a database of spectral sensitivities vs. neutrons’ energy, a mathematical deconvolution process from 7 electric current values virtually measured by SPNDs was started, retrieving spectral information, in terms of 7 energy windows, of the neutron-flux the detectors are subjected by. This paper describes the procedure that led to those results, prefiguring future development to improve proposed method.

Influence of the Parameters of Electrodynamic Actions on the Stressed State of Welded Joints of Sheets of AMg6 Alloy

We study the influence of the parameters responsible for different durations of the electrodynamic actions on the decrease in residual stresses in welded joints of the sheets made of AMg6 aluminum alloy after electrodynamic treatment. It is discovered that as the time of electrodynamic action increases as a result of the increase in the inductance of the discharge contour in the course of electrodynamic treatment performed for constant amplitude values of impulsive electric currents, the period of decay of impulsive electric current is longer than the period of its growth. In this case, the efficiency of electrodynamic treatment increases. It is established that, for the duration of electrodynamic treatment t Σ ≥ 4.5 msec, the decrease in residual stresses is determined both by the intensity of the electrodynamic influence and by the local heat treatment as a result of the Joule heating of the surface of the plate.