Frequency Tunable Graphene Metamaterial Reflectarray

Wireless Personal Communications - In this paper, the radiation characteristics of frequency tunable graphene based metamaterial reflectarray have been investigated. The unit-cell consists of...     

InSb Based Microstrip Patch Antenna Temperature Sensor for Terahertz Applications

Reconfigurable sensing antennas (RSA) play a significant role in modern internet-of-things (IOT) applications. The RSAs are capable of transmiting and receiving electromagnetic waves besides sensing different enviroment parameters. This paper introduces a reconfigurable sensing microstrip patch antenna desinged to sense high temperature variations in harsh environment. The indium antimonide (InSb) semiconductor material is a temperature sensitive material employed in RSA designs in the Terahertz (THz) frequency band. An investigation of the temperature dependency of the electrical properties of the InSb-material is introduced. The proposed sensing antenna introduces high sensitivity of 1.588 GHz shift in resonance frequency per unit change in temperature (Kelvin). The resonance frequency of the InSb sensor antenna is changed according to the surrounding environment temperature from 264 GHz to 502.2 GHz with a broadband tuning range of 90.2%. The InSb patch sensor have temperature sensing range of 150 K starting from 250 up-to 400 K. At 300 K the InSb sensor antenna proposes a peak gain of 6.4 dBi with impedance matching bandwidth of 9.57%. An equivalent circuit consists of five lumped elements is estimated for the InSb sensor antenna using particle swarm optimization (PSO) technique at different temperatures. At T?=?250 K the maximum radiation efficiency is 2.5% and is increased up to 86.3% at T?=?400 K.

     

Circularly Polarized SIW DRA Fed by Ridge Gap Waveguide for 60 GHz Communications

Wireless Personal Communications - A compact planar dielectric resonator antenna (DRA) is designed based on the substrate integrated waveguide (SIW) technology for 60 GHz communications....     

Circularly/Linearly Polarized Low-Profile Plasma Microstrip Antenna for MIMO Applications

Wireless Personal Communications - A polarization reconfigurable square microstrip patch antenna (SMSPA) based on plasma is introduced in this paper. The antenna is designed for mobile...     

Beam-shaping technique for plasma magneto-electric dipole planar array based on time-modulation and particle swarm optimization

Wireless Networks - In this paper, an approach for the synthesis of desired pattern in 4D antenna linear and planar arrays is proposed, taking into account practical element models. The element of...     

Determination of Chlorantraniliprole Residues in Grape by High-Performance Liquid Chromatography

An effective analytical method for the residue analysis of a novel insecticide chlorantraniliprole and its dissipation in grape were studied. Chlorantraniliprole residues were extracted from grape samples with ethyl acetate. The extract was cleaned up with QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method and determined by high-performance liquid chromatography with photodiode array detector (HPLC-DAD). At fortification levels of 0.06, 0.5, and 1.0 mg kg^?1 in grape, it was shown that recoveries ranged from 95.11 to 102 % with relative standard deviation (RSD) of 6 to 11 %. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.02 and 0.06 mg kg^?1, respectively. The dissipation half-life time of chlorantraniliprole residues in grape was 2.70 days. According to maximum residue limit (MRL), the preharvest interval (PHI) of chlorantraniliprole on grape was 4 days after the treatment. Based on the results of this study and the relevant residue regulation, chlorantraniliprole residue levels will be acceptable when applied to grape in Egypt.     

Residue Levels,Profiles, Emission Source and Daily Intake of Polycyclic Aromatic Hydrocarbons Based on Smoked Fish Consumption,An Egyptian Pilot Study

Residue levels and spectrum of polycyclic aromatic hydrocarbons (PAHs) were determined in smoked fish, and canned smoked fish, collected from grocery shops from Cairo, Giza, Menoufya, and Ismailia governorates, Egypt. Residues of PAHs were monitored using gas liquid chromatography, equipped with a flame ionization detector. The concentrations of ∑13 PAHs in the smoked fish and the canned smoked fish ranged from 36.06–547.1 μg/kg, respectively. Benzo(a)pyrene was not detected in smoked canned fish, while its mean residues in smoked fish amounted to 1.1 μg/kg, corresponding to one fifth of the maximum tolerable limit of 5 μg/kg established by EU. The congeners profile showed that the sources of PAHs in the two brands of smoked fish are mainly petrogenic. Based on smoked fish the daily intake of 13 PAHs and benzo(a)pyrene were 45.59 μg/day and 0.092 μg/day, respectively, while for canned smoked fish the intake was fifteen times lower (3 μg/day), and the intake of benzo(a) pyrene is zero μg/day. Results showed that the consumption of smoked fish would pause some risk to consumers; meanwhile canned smoked fish showed no risk to Egyptian consumers.     

Elements Failure Detection and Radiation Pattern Correction for Time-Modulated Linear Antenna Arrays Using Particle Swarm Optimization

Wireless Personal Communications - Array elements failure detection and pattern correction for time-modulated linear array antennas (TMLAA) are investigated in this paper. The particle swarm...