Journal of Kufa - physics

The present study includes preparation of high temperature superconductorBi2Sr2Ca2Cu3O10+and Bi2Ba2Ca2Cu3O10+by solid state reaction (SSR) method. The prepared samples were calcinaed at 800oC for 20 hours ,then regrind and pressed at pressure (0.7 GPa) into pellets, then sintered at 860oC for sintering times (140,160,180 and 200) hr.X-ray diffraction was used to determine the phases ,lattice constants (a,b&c ) and density of orthorhombic systems.Then study effect of sintering time on both two compounds and compare between them ,the highest Tcrecorded with sample (C) (Tc=103 K) for the compound Bi2Sr2Ca2Cu3O10+at sintering time (ts=180 hr) ; and (Tc=96 K ) sample (L) for the compound Bi2Ba2Ca2Cu3O10+at (ts=200 hr) it is the highest Tcrecorded.Also the study appeared prefer ability the first compoundBi2Sr2Ca2Cu3O10+on the other Bi2Ba2Ca2Cu3O10+because it records the highest Tcfor same sintering times ,creasing number of peaks of HTS(2223),up rise intensity and drop value resistively for this search.

Ultrasonic absorption, velocity, viscosity, density, adiabatic compressibility, relaxation time and relaxation amplitudemeasurements are reported onplasticBuna polymer solutions in common solvent Heptanewith deferent concentrationsusing pulsed ultrasonic apparatus technique operating at 26 kHzand 30 ºC, also the molecular weight (vM)has been measured at the same temperature .The results show exchange interactions of polymer-polymer macromolecules and polymer-solvent molecules appeared as increment in values ofvelocity, density, viscosity, and absorption coefficient ,relaxation time and relaxation amplitude values with increasing polymer concentrations. In contrast the compressibility was found decreases with increasing ofconcentration of thispolymer.

The project includes building a system for the preparation of thinfilmsvarious solids by chemical spraypyrolysis method.These films stability and reliability of prohibitively high in the physical properties ofmaterials preparedfrom them,to be supported by the results for the purposes of research and studies. Nickel oxide NiOand cadmium sulfide CdS thin films were prepared using this method. The optical properties of prepared films have been studied in the UV-VIS region of the electromagneticspectrum byrecording of absorbance and transmittance spectrum of the prepared films in thewavelengths range (300-1100) nm. Reflectivity spectra of the prepared films were also studied in the same region. Optical constants of the prepared films, such as absorption coefficient,extinction coefficient and refractive indexcalculatedfrom these spectra. Theprepared films werefound to be of direct energy gap and the value of the forbidden energy gap of the NiO films is 3.694 eV while the value of the CdS films is 2.471eV.

Theaim of this paperis studying of the effect of heattreatmenton glasswhichhas been carried out thermally in the range of (140-170 Co) with an increase of 10Co each step before and after the irradiation with alpha particles emitted from the source of 21084Po with nominalactivity of (0.1μCi) and an energy of (3.34MeV),the energy of activating the thermal treatment (Ea) wascalculated, It has been noticedthat it equals(0.047-0.0718 eV) andit depends basically on the radiation type & glass type

n this research the electrical properties for heterojunction devices have been improved by process of simpleannealing temperature about one hour period. The results have been explained thatthe influential of analysis process on electrical properties during the clearest improve for devicesproperties at special temperature .

The dose gamma ray buildup factor for different materials (Al, Cu and Pb)
up to 20mfp had been calculated using computer programs, which were constructed to
calculate this factor for different materials using Taylor’s formula for point isotropic
source .The programs had been designed to work with any atomic number and energy
by adapting Lagrange interpolation method according to the studied factors (thickness
of the shielding, energy of the gamma ray and atomic number of the shield (.
Key words:
Dose gamma ray for point isotropic source-Dose gamma ray buildup factor-
Taylor’s formula-Lagrange interpolation method.

The mathematical modeldesignconsists ofdifferent equations (deviated from main equations )described the diode pumped solid state laser oscillator performance.In this model the work was concentrated on the main design parameters which have a high influence on laser system performance such as beam overlap efficiency, energy transfer efficiency, and output coupling reflectivity.The parametersare the threshold input power, output power and optimum transmission of output coupler.

The mathematical modeldesignconsists ofdifferent equations (deviated from main equations )described the diode pumped solid state laser oscillator performance.In this model the work was concentrated on the main design parameters which have a high influence on laser system performance such as beam overlap efficiency, energy transfer efficiency, and output coupling reflectivity.The parametersare the threshold input power, output power and optimum transmission of output coupler.

The aim of this work isfocused onpreparation and using gamma-rayspectrometryto investigate and demonstrate a method to determine and evaluate natural radio nuclideswhich areuranium, thorium andpotassium and theiractivityconcentrations, radiumequivalent activity, absorbeddose rates in air at one meter above the ground surface and theannual external and internal effective dose rates . The spectrometer consists of NaI (Tl )detectorcoupledwithpreamplifier and ADC of 4096 Chanel memory , CASSY type. The suitable gain was determined.The efficiency , energy calibration andresolutionhad been measuredbyusing some standard source .. In order to evaluate the radiological impact for the population , four soil samples have beenCollected from different localities in middle area of Najaf province , and measured in which 238U ,232Th and 40K were noted. The value of activity concentration ranged from 4.84±0.52 to 17.52±0.94, 5.92±0.31 to 7.07±0.344 and 103.39±2.52 to 185.48±2.09 (Bq kg-1) for 238U,232Th and 40K respectively . The calculated values of radium equivalent activity (Raeq ) ranged from 25.25 to 33.94 (Bq kg-1) whereas absorbed doses varied from 12.35 to 16.09 (Bq kg-1) . Annual effective Doses were found to be in the range (0.061) to (0.079) and (0.015) to (0.020) (mSv) for indoor and Outdoor respectively . The comparison between our results and standard levels recommended by the IAEA and UNSCEAR show low radiation level .

Mechanical and X-ray scattering measurements on a side-chain liquid-crystal elastomer based on a Siloxanebackbone are presented. The application of a stress field to the elastomer while in the nematic phase result in a stress-induced alignment of the mesogenic units in the direction of the extension. Extensions as low as 2% result in appreciable molecular alignment. The similarities of these effects with those observed in electric and magnetic fields are outlined.

Assessment of radiation absorbed dose by patient in medical X-rays examinations are of great values in the radiation protection field. Fluoroscopic procedures (particularly prolonged interventionalprocedures) may involve high patient radiation doses .ESD were calculated for patients who are examined by fluoroscopy apparatus (long term X-ray examination) that used to visualize the dynamic movement of different movable organs .Parameters that involved in this projects are X-ray tube voltage(KV peak),X-ray exposure factors(mA.s) and distance between X-ray tube and patients skin.35 cases were involved in this projects [15 male and 20 female].mathematical equation was used to assess the ESD .The results show that ESD ranged from 257.742 mGy to 1142.814mGy and of mean 571.2846mGy.