Effects of Electromagnetic Fields on Mammalian Cells

The characteristics of mammalian cells can be influenced by electromagnetic fields (EMFs). The electromagnetic fields have a number of physiological effects on cells and tissues such as alteration of gene expression, cells viability, proliferation, apoptosis, number of mammospheres, cells cycle phase, and invasion. The existing literature proves that the impact of EMFs on mammalian cells depends on the density and uniformity of the field, frequency range, exposure time, cell types, culture environment, and culcuremedium. This paper presents a review of the impacts of EMFs on mammalian cells in vitro culture. In this article, we reviewed the contemporary understanding of the various form of electromagnetic radiation effect on cultured mammalian cells in vitro, EMF exposing systems, and internal field mechanism in the cells.DOI:http://dx.doi.org/10.11591/ijece.v2i2.26

Rectenna circuits for RF energy harvesting in miniature DBS devices.

 Development of an optimum rectenna for radio frequency energy harvesting in miniature head-mountable deep brain stimulation (DBS) devices. The designed miniature rectenna can operate a DBS device without battery for murine preclinical research. The battery-less operation of the device eliminates battery related difficulties

A STUDY ON CAUSES OF KNITTING MACHINE STOPPAGES AND THEIR IMPACT ON FABRIC PRODUCTION

Knitting machine stoppages cause loss of fabric production. The smooth running of knitting machine depends on yarn quality, knitting machine conditions and knitting production conditions. Knitting machine stops due to different causes. In this work it was found that the causes of stoppages are yarn breakages, set-off, machine cleaning and fabric roll cutting, yarn joining, needle breakages and oil problem. The major cause of knitting machine stoppage was machine cleaning and fabric roll cutting. It occupies almost 40.38% of total stoppage time. This cause lead to the production loss of 43.48 kg of fabric. Similarly, yarn breakages, set-offs, and other causes like yarn joining and needle breakages occupied 20.19%; 7.69% and 31.7% of total stoppage time respectively. The knitting machine was stopped for total 312 minutes among 24 hours or 1440 minutes of running due to all of the causes. The causes, combindly led to production loss of 107.66 kg of fabric in 24 hours. Due to the all of the causes total 21.66% of fabric production loss was realized

Parametric Investigation of Near End and Far End Crosstalks in Printed Circuit Board Lands

Multi-conductor transmission line and interconnect carry signals with wide rage of frequencies from sending end to receiving end. The signal in one transmission line may be interupted by the unwanted contributions from the neighboring line conductors. If data speed increases, high frequency effects occur and the signals suffer from difficulties such as ringing, crosstalk, reflections, and ground bounce that seriously hamper the quality of the received signal. In order to estimate the signal quality, signal integrity analysis is needed. In this paper, an attempt has been made to investigate the sensitivity of the near and far end crosstalk on the parameters such as physical geometry of the conductors, electrical property of the substrate and the rise and fall time of excitation signal. The method of moments (MOM) is used to calculate the line parameters for different geometries. The simulation studies are carried out in TNT. The time domain and frequency domain analyses are performed using transmission line model of PSPICE. Moreover, a model is developed and tested in the laboratory. It is observed that the coupling inductance and capacitance vary with the variation of physical geometry and the substrate parameter

Electromagnetic energy harvesting in a head-mountable DBS device using a circular PIFA

A circular planar inverted-F antenna (PIFA) is designed and simulated at the industrial, scientific, and medical (ISM) band of 915 MHz for energy harvesting in a head-mountable deep brain stimulation device. Moreover, a rectifier is designed, and also the interaction of the PIFA with a rat head model is investigated. In the proposed PIFA, the top radiating layer is meandered, and a substrate of FR-4 is used. The radius and the height of the antenna are 10 mm and 1.8 mm, respectively. The bottom conductive layer works as a ground plate, and a superstrate of polyethylene reduces the electromagnetic penetration into the rat head. The resonance frequency of the designed antenna is 915 MHz with a bandwidth of 18 MHz at the return loss of -10 dB in free space. The antenna parameters (e.g. reflection coefficient, gain, radiation efficiency), electric field distribution, and SAR value are evaluated within a seven-layer rat head model by using the finite difference time domain EM simulation software XFdtd. The interactions of the antenna and the rat head model are studied in both functional and biological aspects

Design and analysis of efficient rectifiers for wireless power harvesting in DBS devices

This paper presents an analysis of optimum rectifier circuits for wireless energy harvesting in deep brain stimulation (DBS) devices. Since DBS demands compact and low power consumption devices, small, high conversion efficient, and high output voltage rectifiers need to be developed. The investigation that is presented in this paper is analytical and simulated based. Analysis on a variety of circuit configurations brings more evidence to improve the performance of rectifiers. Analytical parameters influencing the output DC voltage and the efficiency of the rectifiers are described. The operating frequency of the 915 MHz industrial, scientific and medical (ISM) radio band is used in this study. The maximum conversion efficiency of the LC matched half wave rectifier, the Greinacher voltage doubler, the Delon doubler, and the 2-stage voltage multiplier is obtained as 56.34%, 74.45%, 71.48%, and 31.44%, respectively, at the 30 dBm input power level. The corresponding maximum output DC voltages are 6.27 V, 16.83 V, 13.36 V, and 9.20 V. Thus the Greinacher voltage doubler is deemed as the best configuration according to the conversion efficiency and the output voltage measurements

Multi-layer implantable antenna for closed loop deep brain stimulation system

A multi-layer circular planar inverted-F antenna is designed and simulated at the industrial, scientific, and medical (ISM) band of 915 MHz for closed loop deep brain stimulation implant. The ISM band is considered due to the capabilities of small antenna size, high data rate, and long transmission range. In the proposed four-layer antenna, the top three radiating layers are meandered, and a high permittivity substrate and superstrate materials are used to limit the radius and the height of the antenna to 3.5 mm and 2.2 mm, respectively. The bottom layer works as a ground plate. The Roger RO3210 of εr = 10.2 and δ = 0.003 is used as a dielectric substrate and superstrate. The resonance frequency of the proposed antenna is 915 MHz with a bandwidth of 12 MHz at the return loss of -10 dB in free space. The stacked layered structure reduces the antenna size, and the circular shape makes it easily implantable into the human head. The antenna parameters (e.g. 3D gain pattern), SAR value, and electric field distribution within a six layers spherical head model are evaluated by using the finite element method (FEM). The feasibility of the wireless transmission of power, control and command signal to the implant in the human head is also examined. © 2012 IEEE

Parametric investigation and measurement of near end and far end crosstalk in multiconductor microstrip transmission lines

This paper investigates and measures the near end and far end crosstalk in the multiconductor transmission line (MTL) mounted on the PCB by varying the parameters which are associated with physical dimension, characteristic of the substrate and the nature of input signal. With the variation of these factors, the coupling inductance and capacitance vary causing crosstalk. By using the method of moment (MoM), the per unit length parameters are calculated for microstrip lines. Subcircuit model is used to investigate the time domain and frequency domain analysis of near field and far field crosstalk. This parametric investigation is very useful for designing high speed interconnectors on PCB substrates. Some experimental results are presented to validate the analytical findings

Antimicrobial uses for livestock production in developing countries

Antimicrobial is an indispensable part of veterinary medicine used for the treatment and control of diseases as well as a growth promoter in livestock production. Frequent use of antimicrobials in veterinary practices may lead to the residue in animal originated products and creates some potential problems for human health. The presence of antimicrobial residues in animal originated foods may induce serious health problems such as allergic reaction, antimicrobial resistance (AMR), and lead to carcinogenic and mutagenic effects in the human body. The misuse or abuse of antibiotics in human medicine is thought to be a principal cause of AMR but some antimicrobial-resistant bacteria and their resistant genes originating from animals are also responsible for developing AMR. However, the residual effect of antimicrobials in feed and food products of animal origin is undeniable. In developing countries, the community is unaware of this residual effect due to lack of proper information about antibiotic usage, AMR surveillance, and residue monitoring system. It is imperative to reveal the current situation of antimicrobial use in livestock production and its impacts on public health. Moreover, the safety levels of animal feeds and food products of animal origin must be strictly monitored and public awareness should be developed against the indiscriminate use of antimicrobial in animal production. Therefore, the current review summarizes the literature on antimicrobial use in livestock production and its hazardous residual impacts on the human body in developing countries