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Article
Publication date: 1 June 2000

P.Di Barba

Introduces the fourth and final chapter of the ISEF 1999 Proceedings by stating electric and magnetic fields are influenced, in a reciprocal way, by thermal and mechanical…

Abstract

Introduces the fourth and final chapter of the ISEF 1999 Proceedings by stating electric and magnetic fields are influenced, in a reciprocal way, by thermal and mechanical fields. Looks at the coupling of fields in a device or a system as a prescribed effect. Points out that there are 12 contributions included ‐ covering magnetic levitation or induction heating, superconducting devices and possible effects to the human body due to electric impressed fields.

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: 7 September 2012

Arkadiusz Miaskowski, Andrzej Krawczyk and Yoshiyuki Ishihara

The purpose of this paper is to use numerical methods and modelling to estimate the effect of a passive, metallic (conducting) implant on eddy currents distribution in a…

Abstract

Purpose

The purpose of this paper is to use numerical methods and modelling to estimate the effect of a passive, metallic (conducting) implant on eddy currents distribution in a human knee model. There exists a concern among wearers of such implants that they alter electromagnetic field (eddy currents) significantly and there is a need for standardization of that problem.

Design/methodology/approach

The numerical model of a human knee has been built on the base of Visual Human Project and electromagnetic field calculations were carried out using Meep FDTD engine. In total, two scenarios have been considered: the knee model with and without a metallic implant. The knee implant model has been prepared as the knee model with overestimated electrical parameters of bone tissues by titanium metal. Alternating eddy current distribution has then been evaluated for both models using FDTD low frequency algorithm.

Findings

The highest values of eddy currents occurred on the interface between skin and muscle tissues when the model without an implant is considered. However, when the bone tissues have been replaced with titanium metal, the highest values have occurred in the implant (about 100 times higher than the previous one). This means that an implant can be heated by external electromagnetic fields and that the location of the highest values of eddy currents can be shifted to the proximity of the implant. Moreover, one should realize that in this model the implant is like a knee bone with all anatomical details. It has emerged from this that the implant's shape and size are essential when evaluating its effect on eddy currents distribution.

Practical implications

The interaction of electromagnetic field with implants should be generally further investigated, at least for the presumable worst cases. Such investigation has already been done by some researches but they have been devoted to radio frequencies. The authors believe that the presented research will be helpful in the standardization process, when talking about low frequency electromagnetic field.

Originality/value

The presented methodology can be used in the development of computer aid diagnosis systems. Overestimation of electrical parameters of some parts of the model allows us to predict the distribution of electromagnetic field in the model under investigation very quickly. The results presented in the paper can be used during the standardization process.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 July 2015

Alberto Nájera López, Jesus Gonzalez-Rubio, José Manuel Villalba Montoya and Enrique Arribas Garde

Since first small personal exposimeters became available, some studies have characterized personal exposition to radio frequency electromagnetic fields. The effect of body…

Abstract

Purpose

Since first small personal exposimeters became available, some studies have characterized personal exposition to radio frequency electromagnetic fields. The effect of body and relative position of the exposimeter have been also analyzed but some questions are still unanswered. The paper aims to discuss these issues.

Design/methodology/approach

Using three personal exposimeters in four different subjects, the authors characterized and compared measurements in a controlled experiment.

Findings

The authors found statistically significance differences between exposimeters and subjects due to relative position (right and left) and a control position far from the body (center). It should indicate that body and relative position of the exposimeter affect directly to the measurement, conditioning final and average results.

Research limitations/implications

Measurements using personal exposimeters have to be reconsidered and controlled.

Originality/value

The authors test personal exposimeters limitations in real conditions.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 24 July 2019

Dejan B. Jovanovic, Vladimir Stankovic, Nenad N. Cvetkovic, Dejan Krstic and Dragan Vuckovic

The purpose of this paper is to determine the impact of human age on the distribution of electric field and absorbed energy that originates from a mobile phone.

97

Abstract

Purpose

The purpose of this paper is to determine the impact of human age on the distribution of electric field and absorbed energy that originates from a mobile phone.

Design/methodology/approach

This research was performed for frequencies of 900, 1800 and 2100 MHz, which are used in a mobile communication system. To obtain the most accurate results, 3 D realistic model of the child’s head has been created whereby the dimensions of this model correspond to the dimensions of a seven-year-old child. Distribution of the electric field and specific absorption rate (SAR) through the child’s head was obtained by numerical analysis based on the finite integration technique.

Findings

The results discover that amount of absorbed energy is greater in the surface layers of the child’s head model when the electromagnetic (EM) characteristics of tissues are adjusted for the child. This deviation corresponds to different EM characteristics of biological tissues and organs of an adult person compared to a child.

Research limitations/implications

The study deals with penetrated electrical field and absorbed EM field energy. There is space for further studies of other EM field effects (e.g. thermal effects).

Practical implications

The analysis of obtained results leads to idea that mobile phones and devices aimed for children using should be modified to provide SAR values inside prescribed standards.

Social implications

The obtained results are foundation for future research on influence of EM fields of mobile devices on human health.

Originality/value

The proposed procedure offers the model for accurate estimation and quality analysis of SAR and EM field distribution inside child head tissue.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 38 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 July 2012

N. Vidal, J.M. Lopez‐Villegas and J. Sieiro

The purpose of this paper is to study the interaction of electromagnetic fields with biological tissues in the presence of antennas implanted subcutaneously for…

Abstract

Purpose

The purpose of this paper is to study the interaction of electromagnetic fields with biological tissues in the presence of antennas implanted subcutaneously for biotelemetry applications. The authors examined the influence of these radiative devices on energy absorption and also their effects as reflective metal surfaces when incoming radiofrequency energy was present.

Design/methodology/approach

The research was carried out using electromagnetic modeling based on the finite difference time domain method and the calculations were performed to determine the electric field and specific absorption rate. The implanted antenna operated in the Medical Implant Communication Service band. The incoming external electric fields considered included different frequency bands covering most current telecommunications standards.

Findings

Levels of absorbed energy with and without the implanted device.

Practical implications

The paper offers an analysis of results and comparison with current dosimetric standards and guidelines for limiting electromagnetic exposure.

Originality/value

The paper studies the interactions of implanted antennas with biological tissues, taking into account two behaviors: radiative and passive.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 20 June 2016

Boquan Liu, Yicheng Zeng and Pinghua Tang

This paper aims to propose a noise-robust method to estimate the frequency of the reflective echo to reduce the negative effects of noise and improve the accuracy and…

Abstract

Purpose

This paper aims to propose a noise-robust method to estimate the frequency of the reflective echo to reduce the negative effects of noise and improve the accuracy and resolution of a resonant surface acoustic wave (SAW) sensor.

Design/methodology/approach

The proposed approach exploits the singular value decomposition to obtain the frequency information of a SAW response signal and overcome the noise influences.

Findings

Compared with the commonly used Fourier transform (FT) method, the accuracy and resolution improvement of the proposed method used in the SAW sensor is validated.

Originality/value

The system using the proposed method delivers lesser standard deviation, that is, delivers higher performance than the conventional system using the fast FT method.

Details

Sensor Review, vol. 36 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 26 October 2017

Boquan Liu and Pinghua Tang

This paper aims to present an context evaluation and frequency measurement method for surface acoustic wave (SAW) resonant sensor.

Abstract

Purpose

This paper aims to present an context evaluation and frequency measurement method for surface acoustic wave (SAW) resonant sensor.

Design/methodology/approach

This method is based on a signal subspace construction, which, along with assembling optional value set, provides the results.

Findings

The method can assess the application context and improve the resolution and accuracy of the passive wireless SAW resonator sensor system.

Originality/value

Passive wireless SAW resonators have been used as sensor elements for different physical parameters such as temperature, pressure and force in a number of industrial and medical applications. Various wireless channel environments introduce different application contexts.

Details

Sensor Review, vol. 37 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 9 October 2019

Elham Ali Shammar and Ammar Thabit Zahary

Internet has changed radically in the way people interact in the virtual world, in their careers or social relationships. IoT technology has added a new vision to this…

4740

Abstract

Purpose

Internet has changed radically in the way people interact in the virtual world, in their careers or social relationships. IoT technology has added a new vision to this process by enabling connections between smart objects and humans, and also between smart objects themselves, which leads to anything, anytime, anywhere, and any media communications. IoT allows objects to physically see, hear, think, and perform tasks by making them talk to each other, share information and coordinate decisions. To enable the vision of IoT, it utilizes technologies such as ubiquitous computing, context awareness, RFID, WSN, embedded devices, CPS, communication technologies, and internet protocols. IoT is considered to be the future internet, which is significantly different from the Internet we use today. The purpose of this paper is to provide up-to-date literature on trends of IoT research which is driven by the need for convergence of several interdisciplinary technologies and new applications.

Design/methodology/approach

A comprehensive IoT literature review has been performed in this paper as a survey. The survey starts by providing an overview of IoT concepts, visions and evolutions. IoT architectures are also explored. Then, the most important components of IoT are discussed including a thorough discussion of IoT operating systems such as Tiny OS, Contiki OS, FreeRTOS, and RIOT. A review of IoT applications is also presented in this paper and finally, IoT challenges that can be recently encountered by researchers are introduced.

Findings

Studies of IoT literature and projects show the disproportionate importance of technology in IoT projects, which are often driven by technological interventions rather than innovation in the business model. There are a number of serious concerns about the dangers of IoT growth, particularly in the areas of privacy and security; hence, industry and government began addressing these concerns. At the end, what makes IoT exciting is that we do not yet know the exact use cases which would have the ability to significantly influence our lives.

Originality/value

This survey provides a comprehensive literature review on IoT techniques, operating systems and trends.

Details

Library Hi Tech, vol. 38 no. 1
Type: Research Article
ISSN: 0737-8831

Keywords

Article
Publication date: 1 April 1985

William E. Murray

During the past decade, the use of video display terminals (VDTs) in information processing and related applications has grown exponentially. Recent estimates place the…

Abstract

During the past decade, the use of video display terminals (VDTs) in information processing and related applications has grown exponentially. Recent estimates place the number of terminals in the workplace at more than ten million. Along with this rapid growth there has been a concomitant increase in concern about the radiation emissions from the VDT. Several types of radiation can be emitted by the terminal. Cataracts, reproductive problems, and skin rashes have been reported by VDT operators and are alleged to result from radiation exposure. However, measurements of the radiation emissions, when compared to the present occupational exposure standards, lead to the conclusion that the terminal does not present a radiation hazard to the VDT operator.

Details

Library Hi Tech, vol. 3 no. 4
Type: Research Article
ISSN: 0737-8831

Article
Publication date: 1 December 2004

George K. Stylios

Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…

3063

Abstract

Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 16 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

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