د.فاضل عبد الزهرة مراد العارضي

Abstract. A New Microstrip PIFA antenna is proposed for wireless applications. The proposed antenna structure is consisting of microstrip antenna with T shaped slots on the patch and two parallel slots in the ground for bandwidth enhancement. This antenna has been design based on a FR-4. The PIFA antenna design have two an operating frequency of 2.34 GHz and 25.4 GHz with S11 -25 and -15.2 dB, while peak gain is about 2.82 dB, 9.654 dB and directivity is 3.122 dB, 9.776 dB over the operating frequency, respectively. Therefore, it suitable for applications of wireless communication with good matching and return loss characteristics. The proposed design model and performance evaluation of PIFA antenna has been executed by CST Microwave Studio.

Abstract: A bending effect of the multimode optical fiber on the signal that transferred within it has been studied for tow wavelengths 850 and 1550 nm. The bending losses were measured for each wavelength with different bending curvature radii. In addition, the critical radius of curvature was calculated for both wavelengths, it was 0.34 and 0.26 mm of wavelength 850 and 1550 nm, respectively. The results appeared that the bending loses of 1550 nm was less than of 850 nm.

Abstract: Relationships between the variability of annual, seasonal NAO and the annual and seasonal temperatures and relative humidity over Iraq have been investigated. The NCEP/NCAR reanalysis data of the monthly mean surface air temperature and relative humidity over Iraq for the periods (1949-2011), (1949- 2007) have been used in present paper. The corresponding monthly mean values of NAO index, SOI, and have been also used. Monte Carlo methodology as a linear correlation analysis has been used to obtain the correlation co-efficient between the mean surface air temperature and relative humidity over Iraq. The results show that surface air temperature in Iraq is significantly correlated with the climatic index NAO only for northern parts of Iraq. There is a significant negative correlation (-0.7) between surface air temperature over north part of Iraq in winter season and NAO index.

This study aims to find out the effect of increasing the length of the arm of the antenna on the amount of electric and magnetic fields generated between the ends of optical nano antenna and choose the best values, We have been using optiFDTD program to test the effect of change the length of the arms of the antenna on the electric and magnetic fields generated , The results show that the electric and magnetic fields inside the antenna have increased when the length of the arm of the antenna decreased, while the penetration and reflection fields have an increased when the length of the antenna arm increased. Therefore, we can concluded that the decrease in the length of the antenna arm enhancement the reflection and dispersion field generated between the antenna on both ends of the domain account

Abstract Bending effect was studied on reached signal through single mode fiber by two light sources ( Infrared LED model IR333C-A with wavelength 940nm andpure red laser Diode model RLD63NZC5 with wavelength rate 635nm) , Measurements were conducted contacts Postal Service and the communication in Najaf the bending losses were calculated in addition to the critical radius of curvature. These results were compared to theoretical results to find out that both results were very close.