A NEW EXPERIMENTAL STUDY OF MAGNETIC FIELD CONFIGURATION IN THE VICINITY OF THE MEDIUMVOLTAGE ELECTRIC LINES

The limit of the magnetic field produced by the distribution power lines is calculated and measured in an urban area, and consideration of risk perception on the environment, recommends several analysis of this field. In this paper, the level of magnetic field is presented for three configurations of the medium-voltage electric lines (30 kV). The proposed computational method is based on the symmetrical configuration of these lines, applied to the three current-carrying conductor’s vectors. This approach leads to a simple formula involving the distance Ri from the conductor to the point of interest P in space. This theoretical and experimental study takes on consideration the real situations and was done at a 50 m as maximum distance from the tower at the height of 1m , 5m and 9m respectively from the ground. The measured and simulated results of magnetic field were assessed to verify the recommended limits and the possible hazard from exposure of the magnetic field configurations on the environment

A new design of an S/X dual band circular slot antenna for radar applications

International audienceA novel design of dual-band slot antenna with a circular patch for radar applications is presented and studied. It is fed by a micro-strip line and built on a FR-4 substrate with a whole size of 18 X 30 mm2. A dual band printed antenna is created by introducing slots on the radiating element. By this, two bandwidth, covering C and X band, are achieved. In order to obtain a good fundamental antenna design, the initial studies were carried out theoretically, using CST Microwave Studio simulation software. In this case, the frequency range at return loss <10 dB is 5.24 - 6.16 GHz for low frequency and is 7.9 -11.7 GHz for high frequency. In addition, the proposed antenna has good radiation characteristics and stable gains over the whole operating bands. A prototype of antenna is fabricated and tested. Experimental data show good agreement between simulated and measured results

New Design of Multi-Band PIFA Antenna with Reduced SAR for Mobile and Wireless Applications

WOS:000543046000001In this paper, a new multi-band PIFA antenna covering four frequency bands (GSM, Wifi/Bluetooth, 4G LTE and WIMAX) is presented. The proposed method in this work consists of two main phases. The first step consists in determining the electrical and radiation characteristics of the proposed antenna using HFSS simulator. The second step, the effects of this antenna on the human body is examined and the specific spatial peak absorption rate (SAR) in the human head caused by the use of mobile phone is reduced applying the adaptation technique. For this reason, experiments were carried out based on LC resonator placed between the generator and the load and put in series with the short circuit. After optimizing the values of L and C, theoretical and experimental results were compared and discussed to obtain a good compromise between some constraints: (1) simulation and measurement results are in good agreement on the return loss (RL) (= S11), (2) high bandwidth, (3) high radiation efficiency and (4) limited specific absorption rate

The Effect of Miniaturized Circular Antennas on the SAR Reduction for Wireless Applications

International audienc

Morphological, physico-chemical characteristics and effects of extraction solvents on UHPLC-DAD-ESI-MSn profiling of phenolic contents and antioxidant activities of five date cultivars (Phoenix dactylifera L.) growing in Algeria

The aim of this study was to evaluate the morphological, physico-chemical characteristics and in vitro antioxidant activity (DPPH, FRAP, total antioxidant activity, Fe2+-chelating activity and CUPRAC) of five date cultivars (Phoenix dactylifera L.) growing in Algeria. The fruits are characterized as being economically important via their PH values, weight and quality. The highest level of total phenolic and condensed tannins contents was found in 80% methanol extracts. This level ranged from 20.38–69.85 mg GAE/100 g DW and between 3.58 and 60.05 mg CE/100 g DW. The highest total flavonoid contents were found in acetonic extracts. The fruits exerted different antioxidant activities and they were influenced by the extraction solvent. Although they have low phenolic contents, 70% acetone extracts gave the highest antioxidant activities. Using UHPLC-DAD-ESI-MSn analysis, 19 compounds were identified, most detected compounds were found in 70% acetonic extracts. Thus, 70% acetone was found to be the best solvent to run such investigation. Due to date-pathogen, infected Tinnaser date synthesized more or new polyphenols such as O-p-coumaroylshikimic acid and apigenin pentosyl hexoside. Keywords: Antioxidant activity, Date fruit, Morphological, Physico-chemical, UHPLC-DAD-ESI-MSn, Solven