SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080917DOSE RESPONSE OF IRRADIATED XRCT RADIOCHROMIC FILM161165228210.22099/ijsts.2008.2282ENM. J. BUTSONDepartment of Medical Physics, Illawarra Cancer Care Centre,
Crown St, Wollongong, N.S.W, 2500, AustraliaT. CHEUNGDept. of Physics and Materials Science, City University of Hong Kong,
Kowloon Tong, Hong KongP. K. N. YUDept. of Physics and Materials Science, City University of Hong Kong,
Kowloon Tong, Hong KongH. ALNAWAFCenter for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, AustraliaJournal Article20060510– Gafchromic XRCT radiochromic film is a self developing high sensitivity radiochromic film<br />product which can be used for assessment of delivered radiation doses which could match applications such<br />as Computed Tomography (CT) dosimetry. The dose response of Gafchromic XRCT radiochromic film has<br />been measured with reflectance spectrophotometry and desktop scanners. The film automatically changes<br />colour upon irradiation, changing from a yellow to a green/brown colour. Results show a high sensitivity to<br />delivered dose compared to other conventional radiochromic films which is well suited to CT applications<br />where lower applied doses are delivered. Sensitivity is found for this film with a 1cGy applied dose,<br />producing an approximate net optical density change of 0.3 at 636nm and 0.2 net OD using broad band white light. This high sensitivity combined with its relatively energy independent nature around the 100kVp to<br />150kVp x-ray energy range provides a unique enhancement in dosimetric measurement capabilities over<br />currently available dosimetry films for CT applications.SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080917STUDY ON IONIZATION EFFECTS PRODUCED BY NEUTRON INTERACTION PRODUCTS IN BNCT FIELD*167173228310.22099/ijsts.2008.2283ENM. R ESKANDARIPhysics Department, Shiraz University, Shiraz 71454, I. R. of IranL. REZAEEPhysics Department, Shiraz University, Shiraz 71454, I. R. of IranS. MOHAMMADIPhysics Department, Payam Nour University, Fariman 93914, I. R. of IranJournal Article20071120The ionization effects of charged particles produced in neutron interactions for Boron Neutron<br />Capture Therapy are considered here using SRIM Monte Carlo Code. The estimated values of these effects in<br />a Plexiglas acrylic phantom are shown to agree well with the available experimental values in high Boron<br />concentration areas. As expected, the ionization effects from lithium and alpha particles are significant.<br />However in the low Boron areas, proton ionization makes an important contribution and their effect on<br />healthy tissue should not be ignored.SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080917PUSHOUT CROSSED MODULES OF ALGEBROIDS175181228410.22099/ijsts.2008.2284ENM. ALPDumlupinar University, Art and Science Faculty, Mathematics Department, TurkeyJournal Article20080519In this paper, we presented algebroids and crossed modules of algebroids. We also presented pullback crossed module of algebroids and we then define pushout crossed modules of algebroids.SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080917ON THE SYNCHRONIZATION OF COUPLED CHAOTIC SYSTEMS WITH ZERO LYAPUNOV EXPONENTS183190228510.22099/ijsts.2008.2285ENG. H. ERJAEEMathematics Department, College of Sciences, Shiraz University, Shiraz, I. R. of IranJournal Article20050831The threshold of weak and strong synchronization in a coupled chaotic Gaussian map is<br />demonstrated by using the Pyragas’ terminology. However, Vieira and Lichtenberg have shown that the<br />Pyragas’ criteria for weak and strong synchronization cannot be used for all chaotic systems. In this article<br />we demonstrated some interesting synchronization behavior of two coupled chaotic systems with some zero<br />and negative Lyapunov exponents. In such cases the various synchronization behaviors may also depend upon<br />the eigenvalues of a system obtained by subtracting two chaotic systems.SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080906POSITIVE LAGRANGE POLYNOMIALS191195228610.22099/ijsts.2008.2286ENS. M. M. ZEKAVATDepartment of Mathematics, School of Science, Shiraz University, Shiraz, I. R. of IranSH. KHOSHDELDepartment of Mathematics, School of Science, Shiraz University, Shiraz, I. R. of IranJournal Article20070416In this paper we demonstrate the existence of a set of polynomials Pi , 1 i n , which are<br />positive semi-definite on an interval [a , b] and satisfy, partially, the conditions of polynomials found in the<br />Lagrange interpolation process. In other words, if a a1 an b is a given finite sequence of real<br />numbers, then Pi (a j ) ij (ij is the Kronecker delta symbol ) ; moreover, the sum of Pi 's is identically 1.SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080901TRANSITIVITY OF -RELATION ON HYPERMODULES197205228710.22099/ijsts.2008.2287ENS. M ANVARIYEH1Department of Mathematics, Yazd University, Yazd, I. R. of IranS. MIRVAKILIDepartment of Mathematics, Payame-Noor University, Yazd, I. R. of IranB. DAVVAZDepartment of Mathematics, Yazd University, Yazd, I. R. of IranJournal Article20070507¡V In this paper we consider a strongly regular relation ƒá on hypermodules so that the quotient is a<br />module (with abelian group) over a fundamental commutative ring. Also, we state necessary and sufficient<br />conditions so that the relation ƒá is transitive, and finally we prove that ƒá is transitive on hypermodules.SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080901EFFECT OF THE EXTRINSIC AND TEMPORAL CARRIERS ON RADIATIVE RECOMBINATION OF III-NITRIDE NANOSTRUCTURES207213228810.22099/ijsts.2008.2288ENM. ESMAEILI1Department of Basic Science, Islamic Azad University, Damghan Branch, Damghan, I. R. of IranH. HARATIZADEHDepartment of Physics, Shahrood University of Technology, 3619995161, P.O. Box 316, Shahrood, I. R. of IranM. GHOLAMIDepartment of Basic Science, Islamic Azad University, Damghan Branch, Damghan, I. R. of IranB. MONEMARDepartment of Physics, Chemistry and Biology, Linkoping University, SE-581 581 83 Linkoping, SwedenJournal Article20051207Due to many important applications, the group III-Nitride semiconductors have recently attracted<br />remarkable attention among semiconductor researchers and engineers. In this paper, we report on the impact of extrinsic and temporal carriers on the screening of polarization internal fields. The optical efficiency of GaN/AlGaN multiple quantum well (MQW) nanostructures were studied by means of photoluminescence<br />(PL) and time-resolved PL measurements. Extrinsic carriers come from Si doping in the barriers, while<br />temporal carriers originate when the samples are excited by laser beam. The emission peaks of MQWs in PL<br />spectra of the undoped and low-doped samples show a shift towards higher energy levels as excitation<br />intensity increases, while the other samples do not exhibit such a phenomenon due to the dominance of the<br />extrinsic carriers. The transient data confirm the results of the PL measurements.SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080901ON THE SOLVABILITY OF SOME OPERATOR-DIFFERENTIAL EQUATIONS IN COMPLEX DOMAIN215219228910.22099/ijsts.2008.2289ENA. M. AKHMEDOVBaku State University, Department of Mechanics and Mathematics,
Z. Khalilov st., 23, P. O. Box Az-1148, Baku, AzerbaijanY. Y. MUSTAFAYEVABaku State University, Department of Mechanics and Mathematics,
Z. Khalilov st., 23, P. O. Box Az-1148, Baku, AzerbaijanJournal Article20060220In the present paper an operator-differential equation of second order in complex domain is<br />considered when the coefficients have singularity of pole type at the point z=0. A theorem of existence of the<br />solution of the equation is proved and the spectral property of the solution is separately investigated when the<br />coefficients are spectral operators.SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080906CHARACTERIZATION OF A NEW PREPARED Li2B4O7: Mn DOSIMETER FOR γ- IRRADIATION HIGH-DOSE DOSIMETRY221226229110.22099/ijsts.2008.2291ENM. SHARIFZADEHRadiation Applications Research School, Nuclear Science &Technology
Research Institute, P.O. Box 11365-3486, Tehran, I. R. of IranR. GORJIFARDRadiation Applications Research School, Nuclear Science &Technology
Research Institute, P.O. Box 11365-3486, Tehran, I. R. of IranJournal Article20070729A lithium borate thermoluminescence dosimeter with 0.3 wt% of manganese impurity<br />concentration was prepared for high dose levels in the range of 1-30 kGy for gamma irradiation applications.<br />The TLD reader was used for read out purposes from ambient temperature to about 400°C with a heating rate of 6°C/sec. The pre- and post- irradiation anneal temperature was 300°C for 1.5 and 1 hours respectively. The effects of absorbed dose, dose rate, storage time, as well as the temperature and humidity versus pre- and post-irradiation storage time have been studied. The main glow peak was found to occur at 375°C, and the dosimeter response in the range of 1-30 kGy was linear. No significant fading effect of the dosimetric peak was observed after 8 weeks of storage, and the effects of ambient temperature and humidity were less than ±5% at 95% confidence level.SpringerIranian Journal of Science and Technology (Sciences)1028-627632320080906DETERMINATION OF NEUTRON DETECTORS SHIELD USED FOR THE DETECTION OF LANDMINES227233229210.22099/ijsts.2008.2292END. REZAEI OCHBELAGHDepartment of Physics, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil, I. R. of IranH. MIRI HAKIMABADPhysics Department, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, I. R. of IranR. IZADI NAJAFABADIPhysics Department, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, I. R. of IranJournal Article20060916As a result of being hydrogenous moderators, several landmine detection methods based on<br />nuclear techniques have been suggested in recent years. Because of elastic scattering and moderating neutrons from hydrogen atoms in landmines, detection of backscattered neutron shows an anomaly in the reflected thermal neutrons count when a detector scans over a mine. On landmine detection using neutron sources, a detector and its shielding play an important role. In this paper, based on the investigations and calculations performed by MCNP code (Monte Carlo N-Particle transport code), detector shielding materials and their thicknesses have been determined. Therefore, the effects of moderators such as graphite, heavy water, beryllium, polyethylene and boric acid on backscattered neutron flux have been investigated.