Journal of Kufa - physics

n this research we study the effect of coma aberration on point spread function (PSF) for arraysyntheticcircular obscured aperture. The equation of point spread function (PSF)have been derivedfor this case, coma aberration is used indifferent angles for set of obscured circular synthetic apertures, addition to different obscuration ratios, by using MathCAD programs. The results show an increasingthe resolving powerby usingarray synthetic circular obscured apertureand coma aberration leads to decreasethe secondary peaks for point spread function (Apodization).

this work isshow theeffect of quantization on the reconstructed imagein fractal image compression FIC method. it isbased on zero-mean block matching method, atthis method the mean of the range blocks is used instead of traditional offset parameter. This reduces and simplifies the computations of the affine parameters during the encoding process. This method is tested on 8 bits/pixel gray image. The test results conducted on Lena image indicated that the quantization increases compression ratio about (69.6%) and encoding time about (18.6%) but the decreasesofPSNR around (0.3%), The quality of the reconstructed image is good eitherwe use the quantization process or not used it.

Effect of sputtering pressureandpartialpressure on structural properties of TiO2films prepared using DC-sputteringto glass substratewas investigated.sputtering pressures are changed (1.8,2.8,3.8,4.3pa) at constant O2 /Ar Ratio(5%). Measurements reveal that the TiO2films at the sputtering pressure 1.8 pa is amorphous , while at increasing pressure to 2.8 pa becomes crystalline with Rutile phase (110)and when we increase the pressure to 4.3paget crystalline structurewith anatasphase (101).Grain sizeis calculatedpercrystalline structure of the anatas and rutile(15.7)nmand(14.2) nm respectively.For constant sputteringpressure(2.8pa)andchangedO2/ArRatio(10%,15%,20%,25%,30%,35%),TiO2thin films are a amorphous, exceptpercentage (25%)is crystallinewith anatasphase(101)and with grain size (15.7 nm)

Density functional theory was employed to investigate the electronic properties of phynelene and thiophene compounds and their adducts, the interaction between the two structures changes to include six systems. Many important electronic properties were studied in two ways, the vertical energy method and vertical orbital method include the chemical potential, chemical molecular hardness, chemical softness, electrophilic index and polarizability. Full geometry optimization was calculated at the same level of theory. The results showed that the new structures have low chemical hardness with large electrophilicity, and they are more reactive

n this paper,energy levelswerecalculated for two nuclei (148O6,146C8)by applying the nuclear shell model by usingmodified surface delta interaction (MSDI).The(MSDI)succeeded in energy levelscalculation for the configuration (hole-hole (,this case facilitated the calculation of many holes outside closed shell by using the configuration (hole-hole). Computer programs were used to calculate importantcoefficients involvedmainly in calculating energy levels include Clebch -Gordan , Racha coefficient and matrix element for two bodies by using modified surface delta interaction. Comparisonthe current values with the experimental values , it was found current values were in perfectagreementwith the experimental values.

The natural radioactivity due to presence of238U, 232Th and 40K radionuclides in soil ofKufa zone,Najafgovernorate, Iraqweremeasured by using gamma-ray spectrometry NaI(Tl) "3×3".The specific activity of the soil samplesranged from 1.76±2.30 to 77.45±2.35 Bqkg-1with anaverage of 25.23±2.94 Bqkg-1, from 7.92±1.22 to 42.58±1.75 Bqkg-1with an average of 20.09±1.11 Bqkg-1and from 219.58±1176 to 1994.17±16.15 Bqkg-1with an average of 984.30±11.86 Bqkg-1for 238U, 232Th and 40K respectively.The study also examined some radiation hazard indices such as radium equivalent activity (Raeq), Absorbed Dose rates (D), External Hazard Index (Hex) and Internal Hazard Index (Hin).These calculated hazard indices to estimate the potential radiological health risk in soil.The radium equivalent activity (Raeq) values found to vary from 67.80 to 285.80 Bqkg-1, with the averagevalueof 129.74 Bqkg-1, which wasless than permitted value (370 Bqkg-1).Theabsorbed dose rates, ranged from 32.1to 142.08nGyh-1, with a averagevalue of 65.17nGyh-1 that higher than the permissible limit of 55nGyh-1. The external and internal hazard index of soil samples were less than unity

This work deals with structural and electronic properties of trihydroborane-carbonyl BH3-CO as a donor-acceptor molecular system. B3LYP density functional theory was employed with various basis sets to calculate some structural and electronic properties for this system. The calculations include the bond length and angles between atoms. Andsome electronic properties of the studied compound were investigated include the total energy, electronic states, electron affinity, chemical hardness, softness and electrophilic index. The results show that 6-31G (d, p) level of theory gave good agreement values of geometrical parameters with experimental data in comparisonwith other levels

There are two important types of basic gas-insulated apparatus used by electric power industry: i.gas-insulted transmission lines and ii.gas-insulated transformers.SF6−HeMixtureare considered to beusedin circuit breakers, helium has a very blow dielectric strength (~3%that of SF6in uniform fields) and contributes virtually nothing to the dielectricstrength of the mixture. Helium however, complements SF6in terms of its cooling capacity because it is very light, and does not react chemically eitherSF6, or the gas impurities present in commercialSF6, or the system components.The motion of electrons in plasma gas sulfur hexafluoride (SF6) and its mixture with inert gasHein the present of applied uniform electric field is simulated by using the numerical solution of Boltzmann's transport equation technique. The numerical solutions are utilized within the international computer code program called ''NOMAD'' written in FORTRAN 77, by using the Finite difference method.The energy distribution function and the swarm transport parameters of electron accelerated by DC electric field in a mixture of SF6−He, are evaluated and compared with experimental result of drift velocity (vd), average energy (ε̅),characteristic energy (εk) , diffusion coefficient (D) ,and electron mobility (μ).We concludethat the calculation value has a percentage agreement with international published experimental value over the range of E/N in Td units (E is the electric field and N concentration gas molecules). One can interpret theexistence percentage error to the accuracy of the using cross section data for both elastic and inelastic collisions, since their exist many laboratory published data.

In this work, Radon concentrations in drinking water were measured at 42locations in Al-Najaf cities, using RAD-7 radon monitoring system of Durridge company USA. The annual effective dose for all samples of drinking water were estimated by equations depending on UNSCEAR organization.It is found that the radon concentrations in samples in studied area were varied from (2.43±0.879Bq/m3) to (225.5±12.657Bq/m3), while the mean annual effective dose of Ingestion and Inhalation varied from (0.017739μS.y-1) to (1.64615μS.y-1) and (0.088807μS.y-1) to (0.704526μS.y-1) respectively. When the results were compared of radon concentrations with the internationally recommended reference levels (World healthy Organization limit 500 Bq/m3) andthe mean effective annual dose for radonin drink water normal limits of world (1 mSv/y), there were no indications of existence of radon problems in the water sources in this survey. therefore the drinking water in Al-Najaf city is safe as far as radon concentration is concerned.

A quantum mechanical model used tostudy, the electron transfer reaction for the titanium dioxide TiO2,tin dioxide SnO2,and Indium tin oxide ITOsemiconductor and the redox thiopyronine(Tp)moleculedye. Theoretical method wasadapted to calculate the coupling matrix element coefficientfor semiconductor /dye state and the rate constant of electron transfer reaction. The calculated results of rate constant werecompared with experimental and theoretical results show good agreement with these results

In this researchthe mathematical model ofsurface electric currentsinduced on axisymmetric conductive body of revolution has been formulated and solved numerically by implementing the (MoM) method. Computer simulation was developed to solve the model numerically.The resulted radiation pattern was sketched Reduction of sidelobe and beamwidth thickness was achieved by increasing the number of a apertures and changing their corresponding interspaces.