This research aimed at fabricating solar array concentrator. It is one of the best options for solar energy concentration. Compared with other systems, because of the higher concentration ratios and high control focal length, good accept angles, higher efficiency, rigid with high wind, and low cost, the system has been locally designed and fabricated to produce steam. The dimensions of the active aperture area of 3.25 m2 were studied. The absorber receiver, which conveyed water as heat in a closed cycle with an appropriate pump, produced steam at a higher temperature and with more efficiency. The best characterizations of the system are the focal length 1.25 m, concentration ratio 103, optical power 1.2 kW, losses 0.2 kW, and efficiency 60–70%.

In this paper were prepared Magnesium – Zinc ferrites having the chemical formula (Mg1-xZnxFe2O4) ,(X=0.0, 0.4 and 0.6) were prepared by using chemical precipitation method and these samples were annealing at 700ºC for (3hr). Then the structural and physical properties have been measured for the samples prepared. XRD analysis showed that all the samples having face-centered cubic (FCC) structure and is miller indices (220),(331),(222) (400),(422),(511),(440) The Lattice constant (a) increased with the Zinc concentration (8.36 ـــ 8.67 ºA) increase and also increasing of the homogeneous surface structure caused best in the physical properties, while the Microscope examinations showed that the average roughness surface and Grain size (Dnm) were decreasing with the increase in Zn-concentration .

The aim of  present paper to find the contamination  selected area in Salahdin governorate where the radon gas concentration elevated and they are :Al-Qadasaia quarter ,Hamad Shahab village (communication center in past),Al-douloyea town –Youths center, Dijala town ,samara city (in house garden) and finally in Beji city (communication tower) .In this study ,we had employed the trace detector of CR-39, the obtained results shows the radon concentration exceeds the permissible limits which issues by ICRP which is about 200 – 800 Bq/m3  while the concentration in Salah din governorate  is - which refers to the high ratio of depleted  Uranium all over the gubernator