A study of changes to specific absorption rates in the human eye close to perfectly conducting spectacles within radio frequency range 1.5 to 3.0GHZ

This paper investigates changes in specific absorption rates due to metallic spectacles in close proximity with a head of representative electrical properties. Here, the FDTD method is used with a Z directed plane wave to simulate a personal digital assistant held in front of the face. Results confirm that metallic spectacles can significantly change SAR levels at frequencies between 1.5 and 3GHz. Specific attention is given to the energy interaction in the eyes and the nose. Results are given for several common spectacle frame shapes as well as whole head energy absorption comparisons

A multi-band printed monopole antenna

In this paper, we present an antenna design for multiband applications which can cover the GSM 900 (890-960 MHz), DCS (1710– 1880 MHz) and PCS (1850–1990 MHz), UMTS (1920– 2170 MHz), and WLAN2.4GHz (2400-2484MHz) frequency bands. A prototype is built and measured. Results of return loss, radiation patterns, and efficiency are given. The antenna is small, cheap to manufacture, has a low profile and would be suitable for wearable applications, mobile phones and base stations

Specific Absorption Rates in the human head due to circular metallic earrings at 1800MHz

This paper investigates Specific Absorption Rates (SAR) in the human head due to circular metallic earrings at 1800MHz. A Finite-Difference Time-Domain (FDTD) code was used to analyse different sizes and positions of circular earrings near a homogenous cubic phantom. Results showed good agreement with measurements using the flat section of the SAM twin phantom with the DASY4 measurement system. The excitation was a half wave dipole. Metallic loops with a circumference of approximately one wavelength and positioned 14mm away from the phantom increased the 10g SAR by 5 times. The FDTD code has also been used to analyse the effect of metallic earrings when ‘pierced’ through the ear of an anatomically realistic digital human head based on the Visible Human Project. The head is not symmetric and both ears were considered to allow comparison between different heads. The shape of the ear and the size of the earring were found to be very significant when earrings were hung from the human ear

The SAR effects of popular jewellery on the human head

This paper investigates the effects of metallic jewellery on the SAR in the human head. A CW dipole is placed in front of the head to represent a mobile enabled personal data assistant. The FDTD method has been used to simulate an eyebrow ring near a homogeneous SAM phantom at 1.8GHz. Measurements were made on the Loughborough SAM head with the DASY4 measurement system. Simulations were also made with eyebrow rings on the surface of the skin and pierced through the eyebrow of a heterogeneous anatomically realistic human head. Common sizes of eyebrow ring and eyebrow stud have been considered over the frequency range 0.6 to 4.6GHz. Jewellery which was small compared to a wavelength had little effect on the SAR in the head

A study of the effects of metallic pins on SAR using a Specific Anthropomorphic Mannequin (SAM) Head Phantom

This paper presents the effects of facial metallic pins on the Specific Absorption Rate (SAR) in the head, when radiated by a microwave source placed in front of the face. A Specific Anthropomorphic Mannequin (SAM) is adapted for use with a DASY4 and a digitised SAM head is modelled using inhouse Finite-Difference Time-Domain (FDTD) code, enabling comparisons between measurements and simulations. A continuous wave (CW) half-wave dipole is placed in front of the face, representing a communications enabled personal data assistant mobile communications equipment (PDAMCE). Parametric studies have shown that metallic pins that are roughly half a wavelength long placed along the eyebrow, increase the 1g and 10g SARs at 900MHz by around five fold. A greater than five fold increase is seen at 1800MHz. Measurements show very good agreement with simulations

Dilatancy transition in a granular model

We introduce a model of granular matter and use a stress ensemble to analyze shearing. Monte Carlo simulation shows the model to exhibit a second order phase transition, associated with the onset of dilatancy.Comment: Future versions can be obtained from: http://www.ma.utexas.edu/users/radin/papers/shear2.pd

A study of the effects of metallic pins on SAR using a specific anthropomorphic mannequin (SAM) head phantom

This paper presents the effects of facial metallic pins on the Specific Absorption Rate (SAR) in the head, when radiated by a microwave source placed in front of the face. A Specific Anthropomorphic Mannequin (SAM) is adapted for use with a DASY4 and a digitised SAM head is modelled using inhouse Finite-Difference Time-Domain (FDTD) code, enabling comparisons between measurements and simulations. A continuous wave (CW) half-wave dipole is placed in front of the face, representing a communications enabled personal data assistant mobile communications equipment (PDAMCE). Parametric studies have shown that metallic pins that are roughly half a wavelength long placed along the eyebrow, increase the 1g and 10g SARs at 900MHz by around five fold. A greater than five fold increase is seen at 1800MHz. Measurements show very good agreement with simulations

Random close packing of granular matter

We propose an interpretation of the random close packing of granular materials as a phase transition, and discuss the possibility of experimental verification.Comment: 6 page

The ZEPLIN II dark matter detector: data acquisition system and data reduction

ZEPLIN-II is a two-phase (liquid/gas) xenon dark matter detector searching for WIMP-nucleon interactions. In this paper we describe the data acquisition system used to record the data from ZEPLIN-II and the reduction procedures which parameterise the data for subsequent analysis.Comment: 11 pages, 10 figure