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1 – 10 of over 2000
Article
Publication date: 19 December 2017

Mohammad Malikan

The purpose of this paper is to predict the mechanical behavior of a piezoelectric nanoplate under shear stability by taking electric voltage into account in thermal environment.

Abstract

Purpose

The purpose of this paper is to predict the mechanical behavior of a piezoelectric nanoplate under shear stability by taking electric voltage into account in thermal environment.

Design/methodology/approach

Simplified first-order shear deformation theory has been used as a displacement field. Modified couple stress theory has been applied for considering small-size effects. An analytical solution has been taken into account for various boundary conditions.

Findings

The length scale impact on the results of any boundary conditions increases with an increase in l parameter. The effect of external electric voltage on the critical shear load is more than room temperature effects. With increasing aspect ratio the critical shear load decreases and external electric voltage becomes more impressive. By considering piezoelectric nanoplates, it is proved that the temperature rise cannot become a sensitive factor on the buckling behavior. The length scale parameter has more effect for more flexible boundary conditions than others. By considering nanosize, the consideration has led to much bigger critical load vs macro plate.

Originality/value

In the current paper for the first time the simplified first-order shear deformation theory is used for obtaining governing equations by using nonlinear strains for shear buckling of a piezoelectric nanoplate. The couple stress theory for the first time is applied on the nonlinear first-order shear deformation theory. For the first time, the thermal environment effects are considered on shear stability of a piezoelectric nanoplate.

Details

Multidiscipline Modeling in Materials and Structures, vol. 14 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 2 August 2018

Mohammad Malikan

Thermal buckling of double-layered piezoelectric nanoplates has been analyzed by applying an external electric voltage on the nanoplates. The paper aims to discuss this issue.

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Abstract

Purpose

Thermal buckling of double-layered piezoelectric nanoplates has been analyzed by applying an external electric voltage on the nanoplates. The paper aims to discuss this issue.

Design/methodology/approach

Double-layered nanoplates are connected to each other by considering linear van der Waals forces. Nanoplates are placed on a polymer matrix. A comprehensive thermal stress function is used for investigating thermal buckling. A linear electric function is used for taking external electric voltages into account. For considering the small-scale effect, the modified couple stress theory has been applied. An analytical solution has been used by taking various boundary conditions.

Findings

EEV has a considerable impacted on the results of various half-waves in all boundary conditions. By increasing EEV, the reduction of critical buckling temperature in higher half-waves is remarkably slower than lower half-waves. By considering long lengths, the effect of EEV on the critical temperature will be markedly decreased.

Originality/value

This paper uses electro-thermal stability analysis. Double-layered piezoelectric nanoplates are analyzed. A comprehensive thermal stress function is applied for taking into account critical temperature.

Article
Publication date: 7 October 2014

Alexander S. Tonkoshkur and Alexander V. Ivanchenko

The purpose of this paper is to develop a generalized model of the nonlinear conductivity of varistor ceramic suitable for solving problems of prediction and control of ceramic…

Abstract

Purpose

The purpose of this paper is to develop a generalized model of the nonlinear conductivity of varistor ceramic suitable for solving problems of prediction and control of ceramic nonlinearity, stability of varistor properties.

Design/methodology/approach

The modeling of current-voltage characteristic of the intergranular barrier in metal oxide varistor ceramics is based on the development of the algorithm. It includes all the known mechanisms of electrotransfer in a wide range of voltages and currents of the current-voltage characteristics, and also takes into account the deviation of the barrier form the Schottky barrier.

Findings

The models of double Schottky barrier and double barrier of arbitrary form, as well as the algorithms for calculating the current-voltage characteristics of a single intergranular potential barrier and a separate “microvaristor” with the use of the most well-established understanding of the main mechanisms of electrical are developed. The results of current-voltage characteristics modeling correspond to the existing understanding of the nonlinear electrical conductivity varistor ceramics are based on zinc oxide. The model of double barrier of arbitrary form takes into account the deviation of the barrier form the Schottky barrier which is important in predicting the deformation of the current-voltage characteristics of the varistor products in the process of degradation.

Originality/value

The relation between the form of the current-voltage characteristic and the distribution profile of the donor concentration in the surface regions of the semiconductor crystallites constituting the intergranular potential barrier is established. The accumulation of donors in the space charge region leads to the increase in the current on the prebreakdown region of the current-voltage characteristic and the reduction of voltage corresponding to the breakdown region beginning of the current-voltage characteristic. The significant role of the interlayer in the formation of current-voltage characteristic of the intergranular potential barrier is shown.

Details

Multidiscipline Modeling in Materials and Structures, vol. 10 no. 3
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 9 November 2015

Alexander Sergeevich Tonkoshkur and Alexander Vladimirovich Ivanchenko

– The purpose of this paper is modeling the effect of negative capacitance in the capacitance-voltage characteristic of the intergranular potential barrier of varistor structure.

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Abstract

Purpose

The purpose of this paper is modeling the effect of negative capacitance in the capacitance-voltage characteristic of the intergranular potential barrier of varistor structure.

Design/methodology/approach

The modeling of the capacitance-voltage characteristic of the intergranular barrier in metal oxide varistor ceramics is based on the development of the algorithm. It includes all the known mechanisms of electrotransfer in a wide range of voltages and currents, and also takes into account the voltage drop on the intergranular interlayer of intergranular potential barrier.

Findings

The models and algorithms for calculating the capacitance-voltage characteristics of a single intergranular potential barrier with the use of the most established understanding used at the interpretation of the nonlinear conductivity intergranular barrier are developed. The results of the capacitance-voltage characteristics modeling correspond to the existing understanding of the electrical properties on the ac current varistor ceramics are based on zinc oxide. The model allows to predict the behavior of varistors on the alternating current (voltage).

Originality/value

It is established that the recharge of the surface localized states occurs when a voltage is applied to the varistor structure, it can lead to a relaxation decrease in the width of the potential barrier overcome by tunneling electrons in the field emission from the conduction band of the one crystallite in the conduction band of the other crystallite and thus to the current backlog of applied voltage on the phase (i.e. the expression of the negative capacitance effect).

Details

Multidiscipline Modeling in Materials and Structures, vol. 11 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 16 March 2010

Yi Lin and Xiaoya He

The purpose of this paper is to use the general systemic yoyo model to illustrate why electric fields and magnetic fields can manifest each other and interact with each other.

Abstract

Purpose

The purpose of this paper is to use the general systemic yoyo model to illustrate why electric fields and magnetic fields can manifest each other and interact with each other.

Design/methodology/approach

The coordinated interaction of eddy and meridian fields of spinning yoyos is employed as our methodology for the investigation in this paper. At the end, the First Law on State of Motion is beautifully utilized.

Findings

Among many new theoretical discoveries, systemic yoyo models are provided to understand electric currents and the induced magnetic fields, which lead to a distinction between the yoyo structures of permanent magnets and those of the magnetic field induced by electric currents. It is theoretically shown why all fields in nature, such as electric, magnetic, universal, gravitational, and nuclear fields, have to exist in pairs of opposite polarities, even though one polarity might not be visible or recognizable with the current technology. Using the quark structures of spinning yoyos, an explanation is provided for why protons carry positive electric fields, while neutrons are electrically neutral.

Originality/value

One of the originalities of this paper is about its unified theory underlying many observed phenomena of electric and magnetic fields.

Details

Kybernetes, vol. 39 no. 2
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 14 September 2010

Andrej Stermecki, Oszkár Bíró, Kurt Preis, Siegfried Rainer, Klaus Krischan and Georg Ofner

The purpose of this paper is to define a time‐efficient numerical procedure for the extraction of load‐dependent equivalent circuit (EC) parameters of induction machines. The…

Abstract

Purpose

The purpose of this paper is to define a time‐efficient numerical procedure for the extraction of load‐dependent equivalent circuit (EC) parameters of induction machines. The parameters are determined for every operating point, thus their variation due to skin effect and material saturation under arbitrary load condition is taken into consideration.

Design/methodology/approach

Two methods are presented and compared. The first one is based on the numerical simulation of the standard measurement process, yielding an EC with constant parameters. A time‐harmonic finite element analysis is applied in the second method to calculate the load‐dependent EC parameters. Material linearization and the superposition principle for the magnetic flux are employed to define the leakage inductances.

Findings

A distinct load dependence of all EC parameters has been proven as well as the clear disparity between stator and rotor leakage inductances. These effects can only be taken accurately into account by the EC obtained by the second numerical procedure proposed.

Originality/value

The presented method successfully overcomes typical problems of the measurement process and of the standard numerical procedure for EC parameter estimation, thus the obtained EC parameters are load‐dependent while the physical interpretation of the variables and parameters remains straightforward. Hence, the paper of the internal machine variables is enabled.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 18 July 2024

Anindya Bose, Sarthak Sengupta and Sayori Biswas

This study aims to provide a microfluidic blood glucose sensing platform based on integrated interdigitated electrode arrays (IDEAs) on a flexible quartz glass substrate, adhering…

Abstract

Purpose

This study aims to provide a microfluidic blood glucose sensing platform based on integrated interdigitated electrode arrays (IDEAs) on a flexible quartz glass substrate, adhering closely to pertinent electrochemical characterizations.

Design/methodology/approach

Sensors are the key elements of the modern electronics era through which all the possible physical quantities can be detected and converted into their equivalent electrical form and processed further. But to make the sensing environment better, various types of innovative architectures are being developed nowadays and among them interdigitated electrodes are quite remarkable in terms of their sensing capability. They are a well-qualified candidate in the field of gas sensing and biosensing, but even their sensitivities are getting saturated due to their physical dimensions. Most of the thin film IDEAs fabricated by conventional optical lithographic techniques do not possess a high surface-to-volume ratio to detect the target specified and that reduces their sensitivity factor. In this context, a classic conductive carbon-based highly sensitive three dimensional (3D) IDEA-enabled biosensing system has been conceived on a transparent and flexible substrate to measure the amount of glucose concentration present in human blood. 3D IDEA possesses a way better capacitive sensing behavior compared to conventional thin film microcapacitive electrodes. To transmit the target biological analyte sample property for the detection purpose to the interdigitated array-based sensing platform, the design of a microfluidic channel is initiated on the same substrate. The complex 3D Inter Digital array structure improves the overall capacitance of the entire sensing platform and the reactive surface area as well. The manufactured integrated device displays a decent value of sensitivity in the order of 5.6 µA mM−1 cm−2.

Findings

Development of a low-cost array-based integrated and highly flexible microfluidic biochip to extract the quantity of glucose present in human blood.

Originality/value

Potential future research opportunities in the realm of integrated miniaturized, low-cost smart biosensing systems may arise from this study.

Details

Sensor Review, vol. 44 no. 5
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 20 August 2019

Hanan Rosli, Nordiana Azlin Othman, Nor Akmal Mohd Jamail and Muhammad Nafis Ismail

This paper aims to present simulation studies on voltage and electric field characteristics for imperfect ceramic insulators using QuickFieldTM software. Based on previous…

Abstract

Purpose

This paper aims to present simulation studies on voltage and electric field characteristics for imperfect ceramic insulators using QuickFieldTM software. Based on previous studies, it is accepted that string insulator can still serve the transmission line although imperfect of certain insulator exist in a string. However, different materials of porcelain and glass type had made these insulators own different abilities to carry electricity to be transferred to the consumers.

Design/methodology/approach

Cap and pin type of porcelain and glass insulators are used as the main subject for comparison. The simulation works begins with modeling a single insulator, followed by string of ten insulators with their respective applied voltage, that is, 11 and 132 kV. The insulator was modeled in alternate current conduction analysis problem type using QuickField Professional Software. Technical parameters for porcelain and glass insulator were manually inserted in the modeling.

Findings

This paper presents an investigation on the influence of broken porcelain and glass insulators in string for voltage and electric field characteristics. For single insulator, the voltage distribution may literally reduce when experiencing external damages; whereby the broken porcelain insulator condition is worse than the glass insulator. In terms of electric field distribution, the glass insulator is badly affected compared with the porcelain insulator, as it is pulverized comprehensively.

Research limitations/implications

Further work needs to be done to establish whether the experiments of these simulations study will present coequal outcomes. This study endeavors in promoting a good example of voltage and electric field characteristics across high voltage (HV) insulator with the presence of broken insulator in the string.

Practical implications

This study is beneficial to future researchers and manufacturing companies in strategic management and research planning when they involve in the field of HV insulators. It will also serve as a future reference for academic and study purposes. This research will also educate many people on how HV insulators work.

Social implications

This study will be helpful to the industry and business practitioners in training for the additional results and knowledge to be updated in the area of HV insulators.

Originality/value

This paper presents the analysis of porcelain and glass insulators according to their respective logic conditions when broken. Consequently, the existence of a damage insulator in a string may alter the distribution of voltage and electric field which may ultimately lead to the insulation breakdown after some time. This is because the broken insulator may cause other insulators to withstand the remaining voltage allocated for that particular insulator and may affect the insulators in terms of the life span. Therefore, the distribution of voltage and electrical field characteristics in the presence of broken insulators had been studied in this project.

Details

World Journal of Engineering, vol. 16 no. 4
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 1 June 2000

A. Savini

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community…

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Abstract

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 June 2000

K. Wiak

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines;…

Abstract

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

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