A conducting domain surface boundary applied to hybrid FEM-FDTD Electromagnetic Models

A modified boundary surface between the two domains in the hybrid FEM-FDTD technique is presented. This permits a heterogeneous surface to be imposed, allowing selected parts to be represented as being conducting or non-conducting. This enables a reduced surface size to be used in cases where an antenna is above a conducting plane, as well as facilitating a range of other practical scenarios. Examples presented show stable results and good agreement with published data

A conducting domain surface boundary applied to hybrid FEM-FDTD Electromagnetic models

A modified boundary surface between the two domains in the hybrid FEM-FDTD technique is presented. This permits a heterogeneous surface to be imposed, allowing selected parts to be represented as being conducting or non-conducting. This enables a reduced surface size to be used in cases where an antenna is above a conducting plane, as well as facilitating a range of other practical scenarios. Examples presented show stable results and good agreement with published data

Mathematical Model for Calibration of Potential Detection of Nonlinear Responses in Biological Media Exposed to RF Energy

An efficient way to test for potential unsymmetrical nonlinear responses in biological tissue samples exposed to a microwave signal is to observe the second harmonic in a cavity resonant at the two frequencies, with collocated antinodes. Such a response would be of interest as being a mechanism that could enable demodulation of information-carrying waveforms. In this work, an electric circuit model is proposed to facilitate calibration of any putative nonlinear RF energy conversion inside a high quality-factor resonant cavity with a known nonlinear loading device. The first and second harmonic responses of the cavity due to loading with the nonlinear and lossy material are also demonstrated. The results from the proposed mathematical model give a good indication of the input power required to detect any very weak second harmonic signal in relation to the sensitivity of the measurement equipment. Hence, this proposed mathematical model will assist in determining the level of the second harmonic signal in the detector as a function of the specific input power applied

Mathematical Model for Calibration of Potential Detection of Nonlinear Responses in Biological Media Exposed to RF Energy

An efficient way to test for potential unsymmetrical nonlinear responses in biological tissue samples exposed to a microwave signal is to observe the second harmonic in a cavity resonant at the two frequencies, with collocated antinodes. Such a response would be of interest as being a mechanism that could enable demodulation of information-carrying waveforms. In this work, an electric circuit model is proposed to facilitate calibration of any putative nonlinear RF energy conversion inside a high quality-factor resonant cavity with a known nonlinear loading device. The first and second harmonic responses of the cavity due to loading with the nonlinear and lossy material are also demonstrated. The results from the proposed mathematical model give a good indication of the input power required to detect any very weak second harmonic signal in relation to the sensitivity of the measurement equipment. Hence, this proposed mathematical model will assist in determining the level of the second harmonic signal in the detector as a function of the specific input power applied

Cancer incidence in kidney transplant recipients: a study protocol

<p>Abstract</p> <p>Background</p> <p>Different publications show an increased incidence of neoplasms in renal transplant patients. The objective of this study is to determine the incidence of cancer in the recipients of renal transplants performed in the A Coruña Hospital (Spain) during the period 1981–2007.</p> <p>Methods/Design</p> <p>During the study period 1967 kidney transplants were performed, corresponding to 1710 patients. Patients with neoplasms prior to the transplant will be excluded (n = 38). A follow-up study was carried out in order to estimate cancer incidence after transplantation.</p> <p>For each patient, information included donor and recipient characteristics, patients and graft survival and cancer incidence after transplantation. Incident cancer is considered as new cases of cancer after the transplant with anatomopathological confirmation. Their location will be classified according to the ICD-9.</p> <p>The analysis will be calculated using the indirect standardisation method. Age-adjusted cancer incidence rates in the Spanish general population will be obtained from the Carlos III Health Institute, the National Epidemiology Centre of the Ministry of Science and Technology. Crude first, second and third-year post-transplantation cancer incidence rates will be calculated for male and female recipients. The number of cases of cancer at each site will be calculated from data in the clinical records. The expected number of cancers will be calculated from data supplied by the Carlos III Health Institute. For each tumour location we will estimate the standardized incidence ratios (SIRs), using sex-specific cancer incidence rates, by dividing the incidence rate for the transplant patients by the rate of the general population. The 95% confidence intervals of the SIRs and their associated p-values will be calculated by assuming that the observed cancers follow a Poisson distribution. Stratified analysis will be performed to examine the variation in the SIRs with sex and length of follow-up.</p> <p>Competing risk survival analysis methods will be applied to estimate the cumulative incidence of cancer and to identify variables associated to its occurrence.</p> <p>Discussion</p> <p>Information about cancer incidence in kidney transplant patients could be useful to adapt the guidelines on post-kidney transplant follow-up on tumour screening, and evaluate the impact of intervention measures for the prevention of cancer in these patients.</p

Preventing AVF thrombosis: the rationale and design of the Omega-3 fatty acids (Fish Oils) and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED) study

Background: Haemodialysis (HD) is critically dependent on the availability of adequate access to the systemic circulation, ideally via a native arteriovenous fistula (AVF). The Primary failure rate of an AVF ranges between 20-54%, due to thrombosis or failure of maturation. There remains limited evidence for the use of anti-platelet agents and uncertainty as to choice of agent(s) for the prevention of AVF thrombosis. We present the study protocol for a randomised, double-blind, placebo-controlled, clinical trial examining whether the use of the anti-platelet agents, aspirin and omega-3 fatty acids, either alone or in combination, will effectively reduce the risk of early thrombosis in de novo AVF

Designing Augmented Reality Games for Mobile Learning using an Instructional-Motivational Paradigm

Abstract In this paper, several Augmented Reality (AR

Bandwidth enhancement of balanced folded loop antenna design for mobile handsets using genetic algorithms”, National URSI symposium

Abstract-In this paper, a simple folded loop antenna (FLA) for handsets with relatively wideband impedance, designed and optimized using genetic algorithms (GA). The FLA dimensions were optimized and evaluated using GA in collaboration with NEC-2 source code. Configuration of optimal FLA with excellent VSWR covering entirely the required GSM1800 frequency bands was found within the maximum generation. A prototype antenna was tested to verify and validate the GA-optimized antenna structure. The measured data have shown good agreement with predicted ones. Moreover, the capabilities of GA are shown as an efficient optimisation tool for selecting globally optimal parameters to be used in simulations with an electromagnetic antenna design code, seeking convergence to designated specifications

HYBRID

Abstract � A modified boundary surface between the two domains in the hybrid FEM-FDTD technique is presented. This permits a heterogeneous surface to be imposed, allowing selected parts to be represented as being conducting or non-conducting. This enables a reduced surface size to be used in cases where an antenna is above a conducting plane, as well as facilitating a range of other practical scenarios. Examples presented show stable results and good agreement with published data

Dual-Frequency Planar Inverted F-L-Antenna (PIFLA) for WLAN and Short Range Communication Systems

The design and analysis is presented of a low profile and dual- frequency inverted L-F antenna for WLAN and short range wireless communications, providing a compromise between size reduction and attainable bandwidth. The optimum (minimized) volume of 30 x 30 x 8 mm of the proposed antenna gives 8% bandwidth at lower resonant mode of 2400 MHz, while at the higher resonant mode of 5500 MHz a bandwidth of 12.2% is obtained. Both the simulated and measured characteristics of the proposed antenna are shown