The interaction of a helical antenna, mounted on a mobile handset, with a human head phantom is investigated in this paper. Using the Genetic Algorithms (GA) technique combined with the Method of Moments (MoM), an optimization of the antenna structure is achieved regarding the input impedance at the operating frequency. The Finite Difference Time Domain (FDTD) method is then applied to simulate...

OBJECTIVES Our two objectives were to evaluate the feasibility of fetal brain magnetic resonance imaging (MRI) using a fast spin echo sequence at 3.0T field strength with low radio frequency (rf) energy deposition (as measured by specific absorption rate: SAR) and to compare image quality, tissue contrast and conspicuity between 1.5T and 3.0T MRI. METHODS T2 weighted images of the fetal brain...

The specific absorption rate (SAR) estimates the amount of power absorbed by tissue and is determined electrical conductivity E-field. Conductivity can be estimated using Electric Properties Tomography (EPT) but only E-field component associated with $B_{1}^+$</te...

In this paper we propose to attach radio frequency (RF) shields on mobile phone to reduce Specific Absorption Rate (SAR) in the spherical head model. Shields made of ferrimagnetic materials are used to suppress surface currents on the mobile phone. Many kinds of simulation are performed to investigate the effect of various parameters like location, size, shape and thickness of the shield on the...

A two-element phased antenna array for a mobile handset is investigated using the Finite Difference Time Domain (FDTD) method. The array is designed to provide a spatial null in the near field zone in the direction of the human head. The optimisation algorithm to obtain the minimum peak specific absorption rate (SAR) is addressed. The dynamic range of the feeding voltages in relation to the red...

Forty-eight water samples (30 groundwater and 18 surface samples) were collected from the study region. Physical chemical examinations performed on to determine values of various variables. Several graphs, sheets, statistical measures, including sodium solubility percentage (SSP), absorption ratio (SAR), Piper’s diagram, used plot concentration principal ions chloride mass balance (CMB). The co...

Abstract This study reported the results of groundwater quality for drinking and irrigation purposes in Kurukshetra district, Haryana, India. Twelve parameters, namely pH, TDS, TH, sodium (Na+), magnesium (Mg2+), calcium (Ca2+), potassium (K+), chloride (Cl−), sulfate (SO42−), bicarbonate (HCO3−), nitrate (NO3−), fluoride (F−) were evaluated Water Quality Index (WQI) was calculated. Based on WQ...

Salinity is a major limitation ecological factor for plant development in arid and semi-arid regions. The ionic imbalance, deficiency of nutrients and degradation of plant metabolites are caused by saline conditions, are affected by the reduction ratio of potassium (K) then sodium (Na). In this research foliar applications of humic acid (HA) for improve the absorption of K under salt stress was...

INTRODUCTION A multi-antenna transmitter, e.g. in Multi-Input Multi-Output (MIMO) systems, will be implemented in the user equipment (UE) of mobile communication systems in the near future [1]. Applying the standardized procedures [2][3] for obtaining the maximum average Specific Absorption Rate (SAR), which is an evaluation index for RF exposure to human, requires the measurement of the three-...