In the present work , radon concentration was measured indoor buildings in the College of Education for Pure Science/ Ibn Al- Haitham University of Baghdad using detector (CR-39) by counting track of alpha  resulting from decay series of uranium on the detectors which have exposure to air inside the rooms for (30) days , have been applied the equation (1) and (2) to calculate concentrations of Radon and the results showed that all samples were within the allowable range globally except two samples F1 and F2 where concentrations were (445.868Bq/m³) and (436.791Bq/m³) respectively , they were higher than allowable range globally which was (200-300) Bq/m³ recorded by (ICRP) [1] .

In this paper the behavior of the quality of the gradient that implemented on an image as a function of noise error is presented. The cross correlation coefficient (ccc) between the derivative of the original image before and after introducing noise error shows dramatic decline compared with the corresponding images before taking derivatives. Mathematical equations have been constructed to control the relation between (ccc) and the noise parameter.

In this study, concentrations of radon and uranium were measured for twenty six samples of soil. The radon concentrations in soil samples measured by registrant alpha-emitting radon (²²²Rn) by using CR-39 track detector. The uranium concentrations in soil samples measured by using registrar fission fragments tracks in CR-39 track detector that caused by the bombardment of U with thermal neutrons from ²⁴¹ Am-Be neutron source that has flux of 5 ×10³n cm^-2 s^-1.
The concentrations values were calculated by a comparison with standard samples The results show that the radon concentrations are between (91.931-30.645Bq/m³).
The results show that also the uranium concentrat

Background: preparation of root canals is an important step in root canal treatment. Mechanical instrumentation of root canals cause an irregular layer of debris, known as the smear layer. As a result, several studies reported that preferring the removal of the smear layer. Objective: To study the influence of the energy (100 mJ) of Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser at short pulse duration (60 μs)  on smear layer removal of apical third after using Photon induced photoacoustic streaming technique. Materials and methods: Eighteen straight single-rooted mandibular premolars were used. The roots length were uniform to 14mm from the anatomic apex and

The fractional free volume (Fh) in polystyrene (PS) as a function of neutron -irradiation dose has been measured, using positron annihilation lifetime (PAL) method. The results show that Fh values decreased with increasing n-irradiation dose up to a total dose of 501.03× 10-2 Gy.
A percentage reduction of 2.14 in Fh values is noticed after the initial n-dose corresponding to a percentage reduction in the free volume equal to 42.14/Gy.
The total n-dose induces a percentage reduction of 7.26, corresponding to a percentage reduction of 1.45/Gy. These results indicate that cross -linking is the predominant process induced by n-irradiation.
The results suggest that n-irradiation induces structure changes in PS, causing cross-linking

A simple, precise and accurate spectrophotometric method has been developed for simultaneous estimation of sulfanilamide and furosemide in their mixture by using first and second order derivative method in the ultraviolet region. The method depends on first and second derivative spectrophotometry, with zero-crossing and peak to base line and peak area measurements. The first derivative amplitudes at 214, 238 and 266 nm were selected for the assay of sulfanilamide and 240, 260, 284, 314 and 352 nm for furosemide. Peak area at 201222, 222-251 and 251-281 nm selected for estimation of sulfanilamide and at 229-249, 249270, 270-294, 294-333 and 333-382 nm for furosemide. The second derivative amplitudes at 220, 252 and 274 nm for sulfanilamid