Journal of Kufa - physics

Positron Annihilation Lifetime (PAL) technique has been employed to investigate the effect of low doses of -irradiation (in air and vacuum) on the type of polymers namely: polystyrene (PS). A conventional fast-slow coincidence system was used for measuring the positron lifetime spectra. The time resolution of the system was 422±20 ps (the full width at half maximum (FWHM)) at 22Na energy window. The lifetime spectra were resolved into three components by using PFPOSFIT program. The irradiation performed in air (in the presence of oxygen) and under vacuum with β--rays by using (90Sr/90Y) source at room temperature for ten different total dose, ranging from (0.3-12.3) Gy. The o-Ps lifetime parameters were used to determine the microstructure properties, namely: free volume hole size (Vh) and free volume hole fraction (Fh). The parameters were measured as a function of -irradiation dose. The results of -irradiation show that, the influence of -irradiation on o-Ps lifetime, hence the Vhand Fhvalues for samples irradiated in air are less than their values for samples irradiated under vacuum, due to the effect of peroxy and hydroperoxide radicals formed in the presence of oxygen. The results show that cross-linking process is the predominant process as a result of -irradiation PS

In the present work, we have measured the radon gas concentration in ten fertilizers samples for three kinds {mixed fertilizer (M.F), triple super phosphate (T.S.P), single super phosphate (S.S.P)}by using alpha-emitters registrations which are emitted form radon gas in (CR-39) nuclear track detector.The results obtained have shown that the highest averageradon gas concentration in fertilizer sampleswas found in triple super phosphatesample(T.S.P), which was (177.5 Bq/m3) (Iranorigin), while the lowest averageradon gas concentration was found in single super phosphate (S.S.P)sample, which was (72.2 Bq/m3) (Iraqorigin) .Thepresent results show that the radon gas concentration in all fertilizers samples is below the allowed limit from (International Commission of Radiation Protection) (ICRP) agency

The level schemes and transition rates B(E2;) of eve-even 4856Ti isotopes were studied by performing large-scale shell model calculations with FPD6 and GXPF1 effective interactions. Very good agreement were obtained by comparing the first 2+level for all isotopes with the recently available experimental data, but studying the transition strengths B(E2;1..20sg) for all Ti isotopes using constant proton-neutron effective charges prove the limitations of the present large-scale calculations to reproduce the experiment in detail

n this work, Tellurium thin film hasbeen prepared by chemical spray pyrolysis deposition on glass substrates. X-ray diffraction spectrumhave shown that the prepared film has polycrystalline structure and peaks for Tellurium hexagonal structure. Also, the microstructure analysis using optical microscope illustrated the contrast of topography of this thin film which showed highest homogeneity and regularity. The obtained results of this workare in good agreement with the standard X-ray published data [1].Optical properties involved measurement of transmittance, absorptance, and calculation of extinction coefficient in addition to calculation of the absorption coefficient and energy band gap. Optical measurements results showed that optical band gapof prepared thin filmis( 0.5) ev withabsorption coefficient of 104cm-1.

The influence of SiC particles on the physical and mechanical properties for MgO/SiC composites was investigated. MgO matrix was reinforced with (2 wt%,4 wt%,6 wt% and 8 wt% ) of SiC particles which synthesized using powder technology technique. Five samples of each patch have been prepared and supplied to physical properties (green density (G.D) and bulk density (B.D)) and mechanical properties (hardness and compressive strength) were measured. It was observed that the green density of all samples were decreases with increasing SiC particles content. This due to the lower density of SiC than MgO particles. Prepared samples were sintered at different temperatures (800 ̊C, 1100 ̊C, and 1450 ̊C). The bulk density reviled the unaffecting property for samples sintered at 800C and 1100 ̊C, but it was observed a significant increasing in B.D for samples sintered at higher temperature (1450 ̊C). It has been found that Vickers hardness, compressive strength and diametrical strength values increases with increasing sintering temperatureand decreasing with SiC particles content. The purpose of this study was to confirm the influence of SiC addition on some physical and mechanical properties of MgO matrix

In this research we studied some atomic properties of the like ions of the He-atom in the closed shells by using Hartree-Fock(HF)wave function,In this research we calculated(i)non-relativistic energy (Hartree-Fock energy ) for the( O6+,and F7+and we found the correlation energy of the -44.73664 Hartree , O6+-ion-59.11233 Hartree and for the F7+-ion -75.486 Hartree) and we compared these results with some experimental results. we found large agreement .(ii)Nuclear Magnetic Shielding dia for N5+ =1.187X10-4,O6+=1.365X10-4and for F7+ = 1.542X10-4),and (iii) we examined the influence of the atomic number on some atomic properties where Z=7 for Z=8 for O6+-ion and Z=9 forF7

In this work, theenergy levels and reduced electric transition for 182Wisotope hadbeen studied using interacting boson model-1. Also, the nucleus shape was determined through studying potential energy surface;the square of rotational energy and the moment of inertia were calculated. In the present research , the spin and paritywasfoundfor some energy levels which not determined practically , such asthe levels (1.6234, 1.9592, 1.7563) MeV with spin and parity (15, 23and 26)respectively .According to the (IBM-1)itwas found that 182Wisotope involved in symmetry ofSU(3)

In this study Uranium concentration average absorbed dose and average external effective dose were calculated for dusty strom at 8/9/2007 and 27/4/2008 for some middle and west parts in Iraq.The results for specific activity of uranium was in range of (4.44-10.409 Bg/kg) and the absorbed dose range(1.904-4.465 nGy/h)for dusty strom at 8/9/2007 and the average spective activity (6.475-22.680 Bg/kg) and the average absorbed dose (2.777-9.729 nGy/h) for dusty strone 17/4/2008.All The results were lower thane allow was level, but the a culmination ofthe dose of more then one dusty strom may have a damge effect.

We prepared pure (PbS) thin films and doped with 1% (Cu) and (0.1M) by chemical spray pyrolysis technique, and studied the optical properties for pure and doped thin films and the influence of the doping . we get increasing at all optical constants but decreasing in transmittance.

In this research ,we calculate rotational energy and vibritional energy of the Isotope ion(Be9H2)+in the ground state and compare them with the values of rotational energy and vibritional energy of the ion (Be9H1)+using the equations of rotational energy and equations of vibritional energy . Mathcad program used in the calculations of theoretical results.

Samples of composite material have been prepared by using raw material like poly styrene as matrix material,Bentonite Al-Suffra (filler material),Poly vinyl alcohol (binder material) with the state ratios in the research .After preparing Bentonite powder,it had been choose particle size smaller than (100μm) and after conducting the toasting process to powder with different temperature degrees (100,200,300,400 οC)have been added to dissolved polystyrene material in tolouene with the state ratios and temperature degrees (70-80οC)have been used also binder material poly vinyl alcohol(PVA)andhave been studieddielectric properties for the material (Impedance,Loss factor,A.C.conductivity,Dielecric constant) and study of effect temperature , rate of filler and frequency in value of dielectric constant

The objective of presentresearch is to study thechangingin thermal conductivitythermalof unsaturated polyesterresinby additive the silica material(SiO2)as a fillerwith different Weight amount (10%,20%,30%) to resin and study the effect of this additive on thermal conductivity coefficient(k)of theresin .Fourier equation wasusedto calculate the changing in thermal conductivity coefficient(k)for unsaturated polyester resinbefore additionsilica materialand after,where the results showincreasedthermal insulationof the resin by reduced thermal conductivity coefficientvalue after additionthis material. Alsothe value ofthermal insulation increased with increasing of additive percentage of silicaas illustrated in diagrams which represent the relation between thermal conductivity coefficient with temperature.