Mohamed I. Ibrahim

Metamaterial-Inspired Pentaband Monopole Antenna

In this letter, a systematic approach to design a multiband planar monopole antenna loaded with composite right/left-handed (CRLH) unit cells and, as an example, a five-band monopole antenna loaded with three CRLH unit cells are proposed. The five resonant frequencies are located at 950 MHz (LTE-Band 8), 1.31 GHz (GPS-1.227 GHz), 1.58 GHz (GPS-1.57 GHz) (LTE-Band 4, 10, 21, and 24), 1.97 GHz (LTE-Band 1, 23, and 34), and 2.2 GHz (LTE-Band 1, 4, 10, 23, and 40). The proposed antenna is characterized by omnidirectional radiation pattern at the five operating frequencies.

Cardiovascular risk of circulating endotoxin level in prevalent hemodialysis patients

Background Cardiovascular diseases (CVDs) are a major cause of morbidity and mortality in patients with end stage renal disease (ESRD). Circulating endotoxins may have toxic effect on myocardial functions and are speculated as pathogens of accelerated atherosclerosis and hemodialysis (HD) patients. Objective We aimed to assess the possible relation between circulating endotoxin levels and left ventricular functions parameters, common carotid artery intimal media thickness (CIMT) in prevalent HD patients. Patients and Methods Forty stable prevalent HD patients with mean age (47.97 ± 14.42) year using regular conventional hemodialysis sessions in Ain shams university hemodialysis unit, Cairo, Egypt were randomly selected. Diabetics, congestive heart failure and those with history of myocardial infarction or coronary artery disease were excluded from the study. All patients were studied by CBC and routine chemistry, as well as hs CRP, Intact PTH, lipid profile and endotoxin level by ELISA before and after the HD session, Delta change of endotoxin (pre dialysis endotoxin-post dialysis endotoxin) was calculated, resting Doppler echocardiographic and carotid duplex. Results Mean of Pre-HD session serum endotoxin level was (0.356 ± 0.090) EU/mL and the mean of post -HD endotoxin levels was (0.367 ± 0.110) EU/mL. Significant positive correlation between post dialysis endotoxin, MV E/A ratio and grades of left ventricular diastolic dysfunction (P < 0.05) and significant correlation between delta change in endotoxin and EF% (r = −0.36,P = 0.02). By stepwise linear regression analysis for determinants of MVE/A post –HD endotoxin level independently associated with MV E/A ratio (ß = 0.350, P = 0.027). We did not detect any significant correlation between CCA atherosclerosis and neither pre nor post- HD endotoxin level nor with delta change of pre and post HD endotoxin levels. Conclusion Acute increase in post dialytic circulating endotoxin level in prevalent HD patients may be associated with both left ventricular systolic and diastolic dysfunction and that attempts to reduce endotoxin level may have a positive impact on cardiovascular complications in HD Patients.

Design and Performance Analysis of a Miniature, Dual-Frequency, Millimeter Wave Linear Phased Array Antenna

A dual-band phased array antenna prototype for the Federal Communication Commission automotive short-range radar and long-range radar operating at 25.5 and 76.5 GHz with a scaling factor of 1:20 is presented in this paper. A complete design methodology for dual-band phased array antenna is also proposed. A dual-band bowtie antenna that satisfies the application requirements is designed and fabricated. An isolation technique is adopted to minimize the coupling between the closely spaced elements in the array. A full scaled prototype is fabricated on FR4 substrate. The simulated and measured results are in good agreement.

Single/dual-band CSRR-loaded differential-fed square patch antenna with monopolar radiation pattern

A Complementary Split Ring Resonator (CSRR)-loaded differential-fed microstrip square patch antenna with monopolar radiation pattern is proposed. The antenna is based on the TM11 mode of patch antennas. Single band and dual band designs are proposed. The antennas operate at 2.4 GHz Band for Wireless Body Area Networks (WBAN) applications with quasi omni-directional radiation pattern in the antenna plane. The areas of the two antennas are 4.5 cm × 4.5 cm and they have reflection coefficients better than -10 dB.

Pin-Count and Wire Length Optimization for Electrowetting-on-Dielectric Chips: A Metaheuristics-Based Routing Algorithm

Electrowetting-on-dielectric chips are gaining momentum as efficient alternatives to conventional biochemical laboratories due to their flexibility and low power consumption. In this chapter, we present a novel two-stage metaheuristic algorithm to optimize electrode interconnect routing for pin-constrained chips. The first stage models channel routing as a traveling salesman problem and solves it using the ant colony optimization algorithm. The second stage provides detailed wire routes over a grid model. The algorithm is benchmarked over a set of real-life chip specifications. On average, comparing our results to previous work, we obtain reductions of approximately 39 % and 35 % on pin-count and total wire length, respectively.