Series Circuit Research Articles

An analytical method for solving the problem of heat network load flow

The author aimed to develop an analytical solution to the problem of the load flow of a six-, eleven- and twelve-circuit heat network, as well as to solve the problem of optimisation of a multi-circuit heat network, including the choice of the objective function and the determination of a number of variable technical parameters. For accelerating the optimisation process, the method of decomposition of the heat network graph was used. Decomposition involves is cutting the network graph at some nodes for the transition of a multi-circuit scheme to a branched scheme in the form of a tree. Optimisation of each branched circuit was carried out by the dynamic programming method, as a result of which new values of the variable parameters were obtained at the current iteration. Next, the author returned to the multi-circuit scheme to solve the load flow problem and calculate the value of the objective function. The iterative convergence of the decomposition method was not mathematically proven. The author proposed a method for splitting the graph, which eliminates the decomposition procedure when optimising a heat network. The following methods were applied: mathematical modelling of the hydraulic circuit, graph splitting method and the analytical method for solving the algebraic equation of the fourth degree. The following results were achieved: a scheme of the minimum element of a multi-circuit heat network was determined, the possibility of series and parallel circuits of minimum elements was shown, and analytical dependencies for the problem of load flow of a heat network of these schemes were obtained. The proposed analytical solution of the load flow problem for a multi-circuit heat network allows the problem of calculating a complex network to be reduced to the calculation of several minimum elements, which significantly reduces the amount of computational work when modelling a hydraulic circuit. The provided examples show that the calculation error does not exceed 3%.

Collagen and Carbon-ferrous Nanoparticles Used as a Green Energy Composite Material for Energy Storage Devices

Background:: Chrome shavings, a bioactive material, are generated from tannery as waste material. These chrome shaving can be used for the preparation of many value-added products. Objective:: One such attempt is made to use these chrome shaving wastes as a composite bio-battery to produce DC voltage, an alternate green energy source and cleaner technology. Methods:: Chrome shavings are hydrolyzed to make collagen paste and mixed with the ferrous nanoparticles of Moringa oleifera leaves and Carbon nanoparticles of Onion peels to form electrolyte paste as base. Then, the electrolyte base was added to the aluminum paste and conducting gel, and mixed well to form composite material for bio-battery. Results:: The composite material of bio-battery has been characterized using Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). Series and parallel circuit testing were done using Copper and Zinc electrodes or Carbon and Zinc electrodes as the battery terminals in the electrolyte paste. The surface area of these electrodes needs standardization from bench to pilot scale. The power generated, for an AA battery size, using a single bio-battery cell has produced a DC voltage of 1.5 V; current of 900 mA. Circuit testing on 1 ml of 80 well-cells connected in series has produced DC output of 18 V and 1100 mA whereas 48 V and 1500 mA were obtained from a series-parallel connection. Conclusion:: The glass transition temperature (Tg) of electrolyte of the bio-battery at 53°C indicated that at this temperature, all the substances present in the bio-battery were well spread and consistently contributed to the electrolyte activity where Fe-C-nano-particles were able to form strong chemical bonds on the flanking hydroxyl group sites of the collagen leading to reduced mobility of polymers and increased Tg. The results instigate promising trends for commercial exploitation of this composite for bio-battery production.

Detection of Gadolinium with an Impedimetric Platform Based on Gold Electrodes Functionalized by 2-Methylpyridine-Substituted Cyclam.

Gadolinium is extensively used in pharmaceuticals and is very toxic, so its sensitive detection is mandatory. This work presents the elaboration of a gadolinium chemical sensor based on 2-methylpyridine-substituted cyclam thin films, deposited on gold electrodes, using electrochemical impedance spectroscopy (EIS). The 2-methylpyridine-substituted cyclam (bis-N-MPyC) was synthesized in three steps, including the protection of cyclam by the formation of its CH2-bridged aminal derivative; the product was characterized by liquid 1H and 13C NMR spectroscopy. Spin-coated thin films of bis-N-MPyC on gold wafers were characterized by means of infrared spectroscopy in ATR (Attenuated Total Reflectance) mode, contact angle measurements and atomic force microscopy. The impedimetric chemical sensor was studied in the presence of increasing concentrations of lanthanides (Gd3+, Eu3+, Tb3+, Dy3+). Nyquist plots were fitted with an equivalent electrical circuit including two RC circuits in series corresponding to the bis-N-MPyC film and its interface with the electrolyte. The main parameter that varies with gadolinium concentration is the resistance of the film/electrolyte interface (Rp), correlated to the rate of exchange between the proton and the lanthanide ion. Based on this parameter, the detection limit obtained is 35 pM. The bis-N-MPyC modified gold electrode was tested for the detection of gadolinium in spiked diluted negative urine control samples.

Synthesis and study of the structural and dielectric properties of La0.67Ca0.2Ba0.13Fe1−xMnxO3 ferrites (x = 0, 0.03 and 0.06)

The La0.67Ca0.2Ba0.13Fe1−xMnxO3 perovskite compounds with different manganese concentrations (x = 0.0, 0.03, 0.06) were synthesized by the autocombustion method and annealed at 700 °C. The X-ray diffraction (XRD) data indicated that all obtained compounds crystallize in the cubic structure with the Pm $$\overline{3}$$ m space group. The increase in the substitution rate has been found to lead to the decrease in the crystallite size value characterized by X-ray diffraction. The dielectric properties of these samples, using a complex impedance spectroscopy technique, were also performed as a function of frequency and temperature. A suitable equivalent electrical circuit was used to assess the contributions of electrode, grains, and grain boundaries in the complex impedance results. Activation energies were determined from different methods. Nyquist plots were consistent with three circuits in series, each one with a capacitance in parallel with a resistance. The conduction mechanism follows the NSPT model for the three samples at T < 280 K, in which the rise in substitution rate increases the binding energy of carriers. Above 280 K, the appropriate model is the Correlated Barrier Hopping (CBH) for x = 0, while the overlapping large polaron tunneling (OLPT) process has been confirmed for both samples x = 0.03 and x = 0.06. Our compounds have high electrical properties, and good thermal and chemical stability. They are susceptible to many technological applications, such as gas sensors, capacitors, filters, resonators, new read heads, and solid oxide fuel cells.

Nonlinear dynamics of a RLC series circuit modeled by a generalized Van der Pol oscillator

Abstract In this paper, nonlinear dynamics study of a RLC series circuit modeled by a generalized Van der Pol oscillator is investigated. After establishing a new general class of nonlinear ordinary differential equation, a forced Van der Pol oscillator subjected to an inertial nonlinearity is derived. According to the external excitation strength, harmonic, subharmonic and superharmonic oscillatory states are obtained using the multiple time scales method. Bifurcation diagrams displayed by the model for each system parameter are performed numerically through the fourth-order Runge–Kutta algorithm.

Second-Order Analytic Extension of Eigenvalues for Fast Frequency Sweep Analysis of RF Circuits

A second-order analytic extension of eigenvalue (AEE) method is presented and investigated for efficiently computing the Z- parameters of passive RF circuits over a wide frequency band with full-wave accuracy. The Z- parameters of an RF circuit are first extracted based on a full-wave simulation on sampling frequencies and then decomposed into eigenmodes, whose eigenvalues are analytically extended to all other frequencies within the frequency band of interest based on functional equations constructed from second-order series and parallel RLC circuits. An eigenvector-eigenvalue identity is adopted to compute the frequency-dependent eigenvectors from the eigenvalues of the submatrices, which are used in the expansion of the Z- parameters. A comparison with full-wave solutions is given for the second-order AEE where four frequencies are employed to accurately approximate the Z- parameters and predict the frequency response over the entire band of interest that goes to much higher frequencies than the first-order AEE. With this, the previously developed first-order AEE for a quasi-static analysis is successfully extended to much higher frequencies. Numerical examples are provided to validate the accuracy and demonstrate the capability of the second-order AEE. It is found that the second-order AEE is very accurate for modeling RF circuits with electrical sizes up to one wavelength that possibly contains resonances, as compared to the first-order AEE, which is applicable only to RF circuits with electrical sizes smaller than one-tenth to one-fifth of a wavelength that contains no resonance.

Nondestructive Detection of the Gel State of Preserved Eggs Based on Dielectric Impedance.

After completing the production of preserved eggs, traditionally, the degree of gelling is judged by allowing workers to tap the preserved eggs with their fingers and sense the resulting oscillations. The amount of oscillation is used for the quality classification. This traditional method produces varying results owing to the differences in the sensitivity of the individual workers, who are not objective. In this study, dielectric detection technology was used to classify the preserved eggs nondestructively. The impedance in the frequency range of 2–300 kHz was resolved into resistance and reactance, and was plotted on a Nyquist diagram. Next, the diagram curve was fitted in order to obtain the equivalent circuit, and the difference in the compositions of the equivalent circuits corresponding to gelled and non-gelled preserved eggs was analyzed. A preserved egg can be considered an RLC series circuit, and its decay rate is consistent with the decay rate given by mechanical vibration theory. The Nyquist diagrams for the resistance and reactance of preserved eggs clearly showed that the resistance and reactance of gelled and non-gelled eggs were quite different, and the classification of the eggs was performed using Bayesian network (BN). The results showed that a BN classifier with two variables, i.e., resistance and reactance, can be used to classify preserved eggs as gelled or non-gelled, with an accuracy of 81.0% and a kappa value of 0.62. Thus, a BN classifier based on resistance and reactance demonstrates the ability to classify the quality of preserved egg gel. This research provides a nondestructive method for the inspection of the quality of preserved egg gel, and provides a theoretical basis for the development of an automated preserved egg inspection system that can be used as the scientific basis for the determination of the quality of preserved eggs.

A new approach for modelling the damped Helmholtz oscillator: applications to plasma physics and electronic circuits

In this paper, a new approach is devoted to find novel analytical and approximate solutions to the damped quadratic nonlinear Helmholtz equation (HE) in terms of the Weiersrtrass elliptic function. The exact solution for undamped HE (integrable case) and approximate/semi-analytical solution to the damped HE (non-integrable case) are given for any arbitrary initial conditions. As a special case, the necessary and sufficient condition for the integrability of the damped HE using an elementary approach is reported. In general, a new ansatz is suggested to find a semi-analytical solution to the non-integrable case in the form of Weierstrass elliptic function. In addition, the relation between the Weierstrass and Jacobian elliptic functions solutions to the integrable case will be derived in details. Also, we will make a comparison between the semi-analytical solution and the approximate numerical solutions via using Runge–Kutta fourth-order method, finite difference method, and homotopy perturbation method for the first-two approximations. Furthermore, the maximum distance errors between the approximate/semi-analytical solution and the approximate numerical solutions will be estimated. As real applications, the obtained solutions will be devoted to describe the characteristics behavior of the oscillations in RLC series circuits and in various plasma models such as electronegative complex plasma model.

The effect of addition of vegetable waste on microbial fuel cell performance

In the past few years the fuel cell has become the centre of attention of the scientific community for the possibility of converting organic waste into electricity directly through redox reactions with the help of bacteria or enzymes. The purpose of this study was to determine the value of MFC performance due to the influence of adding vegetable waste. The soil media used is obtained from agricultural areas. The system used in the MFC is a single chamber of a vessel with a volume of 500 mL. The types of electrodes used are carbon fibres with anode thickness of 0.5 cm and cathode 1.0 cm, as well as anode diameter of 8.0 cm and cathode 8.5 cm. Vegetable wastes were given 5 mg / L each in the MFC single chamber. The results showed that the highest power was generated from a microbial fuel cell with spinach vegetable waste. The power produced is 250 mW (49 mW/cm2). The incubation period for MFC can reach 30 days. Variation of the second rinse with a concentration of 499 ppm will have a pH value having a pretty good linear correlation of 0.9536 to the more electric power generated. The power produced by the MFC 6 series circuit is 1.00 mW, while the power generated by the parallel series is 0.831mW.

Smart Cementitious Composites for Road Traffic Monitoring and Weighing in Motion

The addition of electrically conductive materials at micro scale, such as carbon fibres (CF) or steel fibres (SF), to conventional cementitious materials makes piezo-resistive behaviours possible in terms of changes in electrical resistivity due to applied stresses. Smart cementitious composites (SCCs) may thus be able to detect traffic density and sense weight in motion thanks to such piezo-resistive property. Three types of cement-based sensors, with CF, SF, or a hybrid of CF and SF, were experimentally evaluated by applying quasi-static and dynamic load cycles after seven days of curing in different load directions reflecting the electrodes and different circuit type connections of the specimens. The performance of each type of sensor was assessed based on measuring the changes in electrical resistivity (ER) under compressive and flexure stresses, with test results revealing that the use of CF in these composites was the best choice because this generated more sensitivity to applied loads in terms of the change in ER compared with other types. These results were achieved when the applied load was parallel to the electrode direction. The findings also indicated arrangement of specimens as an electric series circuit type was the best setup configuration for traffic monitoring and weight in motion measurement.

The study on model of variable and motors resistance on series circuit in the stalled DC motor

The stall phenomenon which happens in loaded motor is unqualification in application. Meanwhile it may measure the maximum property of DC (direct current) motor in manufacture. So the phenomenon is analyzed to find a simulation of electrical state to predict the maximum currency and torque which is a necessary method to be proceeded up to now before design. We find that the simulation fits well to the reference. The conditions of t=6s, R2=25Ω, U=20V result in the biggest stall force according to rotation to change time and voltage. Then it is t=8s, R2=20Ω, U=16V; t=10s, R2=15Ω, U=12V and t=12s, R2=10Ω, U=8V in turns. As for torque it is t=6s, R2=25Ω, U=20V; t=8s, R2=20Ω, U=16V; t=6s, R2=25Ω, U=20V and t=12s, R2=10Ω, U=8V in turns. With increasing resistance R1 the power increases to 4W with 8V, and then to 6WËŽ 7WËŽ 10W with 12VËŽ16VËŽ20V respectively. With the increasing voltage and resistance R2 and decreasing time the power will be bigger.

Application of Electromagnetic Shunt Damper to Subharmonic Resonance of Superconducting Magnetic Levitation System

This study investigates the effectiveness of the electromagnetic shunt damper for reducing the amplitude of nonlinear resonance of a superconducting magnetic levitation system by numerical calculation. An electromagnetic shunt damper, a type of dynamic vibration absorber, can suppress mechanical vibration of the main system by converting a part of its vibration energy into electric energy of a subsystem consisting of an electric circuit. Since the electromagnetic force caused by superconductors has nonlinearity, complicated nonlinear resonance can occur in the superconducting magnetic levitation system in addition to its main resonance. This study especially focuses on 1/2-order subharmonic resonance, which can generate a larger vibration component at half the excitation frequency. Numerical calculations were carried out to examine how two types of electromagnetic shunt dampers consisting of LCR series and parallel circuits can effectively suppress this nonlinear resonance. As a result, it was confirmed that the parallel type electromagnetic shunt damper is more effective in reducing the amplitude of the subharmonic resonance than the series type, even under the condition of a larger excitation amplitude.

Design of spike voltage generation system for tank gun ammunition setting test

In order to test the voltage spike interference of the tank gun ammunition setter, a spike voltage generation system is designed in this paper. The system adopts rectifier filter and series voltage stabilizing circuit, combined with single chip microcomputer control circuit, and converts 220V, 50HZ alternating current into spike voltage through post-stage RLC series circuit, and studies the influence of post-stage circuit inductance value on spike voltage rise time. Theoretical calculations and simulations verify that the system can generate spike voltages that comply with GJB298-87, which is of great significance to the test of voltage spike interference of tank artillery ammunition mounters and other military vehicle electronic equipment.

Learning Ohm's Law through Electric Puzzle Media

Electrical circuit components or electronic circuits can be connected with series and parallel circuits. The arrangement of the circuit can affect the desired lamp characteristics. This study aims to measure the magnitude of resistance in an electrical circuit, analyze the flame of a series and parallel resistance, explore the relationship between voltage (V) with current (I) in series and parallel circuits. The method research used quantitative methods based on the problem-solving laboratory. The laboratory equipment used consists of a battery, incandescent lamps, resistors, stacking and zinc puzzles, multimeters, jumper cables. The laboratory equipment assembled and measured the intensity of the light produced using the physics toolbox application on a handphone. The data has obtained, then presented in a table and calculated using a formula, and analyzed the uncertainty in its measurement. The result showed the intensity of light in a series of different magnitude, the power of the light was more significant in lamp one, and in lamp two, the power was smaller. The intensity of the light in the parallel circuit was the same magnitude. Still, the value of the light intensity in the parallel circuit was smaller than the intensity in the lamps arranged in series. The relationship between voltage (V) and current (I) in both series and parallel circuits was comparable and directly proportional. Thus, the developed series of electric puzzles can adequately explain Ohm’s law. Ohm’s law learning with electric puzzles can be used in school and learned by students quickly.

저등급 열원으로 구동되는 직렬 열병합 발전시스템의 엑서지와 엔트랜시 성능 특성

저등급 열원으로 구동되는 직렬 열병합 발전시스템의 엑서지와 엔트랜시 성능 특성

Pembuatan KIT Sederhana Rangkaian Listrik Dinamis Sebagai Produk Akhir Pada Mata Kuliah Praktikum IPA

Learning physics is of course a part of science and should be able to facilitate students to do lab sessions or experiments to prove the concepts learned. One of them relates to dynamic electricity at the secondary level. However, there are still many schools that do not have practical tools that can assist students in learning dynamic electricity equipment. Therefore, the writing of this article is to explain the process of making a simple KIT dynamic electrical circuit as the final product in the science practicum course. The process to create this KIT consists of three stages, namely preparation, implementation and testing. Based on the work carried out, this appears 1). The process of making a dynamic electrical circuit KIT is divided into two parts, namely making tool sets and storage boxes, and 2). Practical activities that can use this electrical circuit KIT include measuring the size of GGL on the battery, measuring the voltage and electrical current, as well as series and parallel circuits

PENGEMBANGAN PANDUAN PRAKTIKUM LABORATORIUM VIRTUAL PADA MATERI ARUS LISTRIK SEARAH

Abstract: The rapid development of technology has an influence on the world of education. Physics is one of the subjects that are considered difficult so that the need for supporting activities is practicum activities. Practicum activities can be done using a virtual laboratory. This study aims to develop a virtual laboratory practical guide for direct current electric material in class XII semester 1 at SMA Negeri 4 Metro Tejo Sari, Metro Timur District which is expected to support the physics learning process, especially the subject of series circuits, parallel circuits and Kirchhoff's law. The type of research used is research and development (R&amp;D). The model used is a 4D model developed by Thiagarajan. This model consists of 4 stages, namely define (analyze needs), design (design a product), development (develop the designed product), and finally desseminate (disseminate the product). The instrument used is an assessment questionnaire. There are two types of questionnaires used, the first is a material and media expert validation questionnaire, and the second is a student and teacher response questionnaire. The practical guide used for virtual laboratory practicum activities is made in web format (.html) using Articulate Storyline 3 media. The results of the material and media expert validation test obtained an average percentage value of 84.59% with a very decent category. The practicality of the virtual laboratory practicum guide obtained an average percentage value of 82.05% in the very practical category. This proves that the virtual laboratory practical guide on direct current electric material can be used in learning activities at school. The virtual laboratory practicum guide should be operated using a computer with a fairly stable internet connection.

Liquid-solid triboelectric nanogenerators array and its applications for wave energy harvesting and self-powered cathodic protection

A new type of array combination for liquid-solid triboelectric nanogenerators is constructed by using polytetrafluoroethylene ultrafiltration membrane as the friction layer with water to collect wave energy to self-power the cathodic protection system in marine environment. The dual liquid-solid triboelectric nanogenerator array shows the output performance with a short current circuit of 2.68 μA and output voltage of 105 V. Meanwhile, a self-powered corrosion protection system with liquid-solid triboelectric nanogenerators array as the power supply is achieved for A3 carbon steel in 3.5 wt% NaCl solution. The electrochemical measurements results show that compared with the bare carbon steel, the open circuit potential drop of the carbon steel coupled with the liquid-solid triboelectric nanogenerators is about 330 mV. Compared with photocathodic protection and other new energy-based methods, the solid-liquid triboelectric nanogenerator could realize all-weather protection of metals by utilizing natural energy and through parallel or series circuit design, it could be used to achieve more efficient cathodic protection for metal materials. The intelligent self-powered system possesses great potential in the area of all-weather cathodic protection and power supply by utilizing liquid-solid friction energy for the ships, buoys, and marine equipments in ocean conditions.

Investigation of Hybrid-Magnet-Circuit Variable Flux Memory Machines With Different Hybrid Magnet Configurations

This article investigates and compares the electromagnetic performance of two novel hybrid-magnetic-circuit variable flux memory machines (HMC-VFMMs) with different hybrid permanent magnet (PM) configurations. The investigated HMC-VFMMs are both geometrically characterized by a combination of series and parallel magnetic circuit topologies, but with different positions of series and parallel PM branches. The developed HMC design can combine the merits of wide flux adjustment range in parallel structure and excellent unintentional demagnetization withstand capability in series structure. The topologies, features, and working principles of the studied HMC-VFMMs with different hybrid magnet configurations are described, respectively. The magnetic circuit model is utilized to analytically reveal the performance metrics of the two machines. The electromagnetic characteristics of the radially magnetized (RM) and circumferentially magnetized LCF types of HMC-VFMMs are evaluated and compared by the finite-element method. Furthermore, the performance comparison of the proposed RM-type HMC-VFMM with a benchmark interior PM machine is conducted. The experiments on RM-type HMC-VFMM prototype with RM-structure are carried out to validate the FE analyses.

A New Approach for Solving the Undamped Helmholtz Oscillator for the Given Arbitrary Initial Conditions and Its Physical Applications

In this paper, a new analytical solution to the undamped Helmholtz oscillator equation in terms of the Weierstrass elliptic function is reported. The solution is given for any arbitrary initial conditions. A comparison between our new solution and the numerical approximate solution using the Range Kutta approach is performed. We think that the methodology employed here may be useful in the study of several nonlinear problems described by a differential equation of the form z ″ = F z in the sense that z = z t . In this context, our solutions are applied to some physical applications such as the signal that can propagate in the LC series circuits. Also, these solutions were used to describe and investigate some oscillations in plasma physics such as oscillations in electronegative plasma with Maxwellian electrons and negative ions.