eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-17
32
3
161
165
10.22099/ijsts.2008.2282
2282
DOSE RESPONSE OF IRRADIATED XRCT RADIOCHROMIC FILM
M. J. BUTSON
martin.butson@sesiahs.health.nsw.gov.au
1
T. CHEUNG
2
P. K. N. YU
3
H. ALNAWAF
4
Department of Medical Physics, Illawarra Cancer Care Centre, Crown St, Wollongong, N.S.W, 2500, Australia
Dept. of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong
Dept. of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong
Center for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
– Gafchromic XRCT radiochromic film is a self developing high sensitivity radiochromic filmproduct which can be used for assessment of delivered radiation doses which could match applications suchas Computed Tomography (CT) dosimetry. The dose response of Gafchromic XRCT radiochromic film hasbeen measured with reflectance spectrophotometry and desktop scanners. The film automatically changescolour upon irradiation, changing from a yellow to a green/brown colour. Results show a high sensitivity todelivered dose compared to other conventional radiochromic films which is well suited to CT applicationswhere lower applied doses are delivered. Sensitivity is found for this film with a 1cGy applied dose,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 to150kVp x-ray energy range provides a unique enhancement in dosimetric measurement capabilities overcurrently available dosimetry films for CT applications.
http://ijsts.shirazu.ac.ir/article_2282_010aa6b357cd1ef8efe369b2d6e8a932.pdf
radiochromic film
Gafchromic XRCT
radiation dosimetry
absorption spectra
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-17
32
3
167
173
10.22099/ijsts.2008.2283
2283
STUDY ON IONIZATION EFFECTS PRODUCED BY NEUTRON INTERACTION PRODUCTS IN BNCT FIELD*
M. R ESKANDARI
eskandari@physics.susc.ac.ir
1
L. REZAEE
2
S. MOHAMMADI
mohammadi@pnu.ac.ir
3
Physics Department, Shiraz University, Shiraz 71454, I. R. of Iran
Physics Department, Shiraz University, Shiraz 71454, I. R. of Iran
Physics Department, Payam Nour University, Fariman 93914, I. R. of Iran
The ionization effects of charged particles produced in neutron interactions for Boron NeutronCapture Therapy are considered here using SRIM Monte Carlo Code. The estimated values of these effects ina Plexiglas acrylic phantom are shown to agree well with the available experimental values in high Boronconcentration areas. As expected, the ionization effects from lithium and alpha particles are significant.However in the low Boron areas, proton ionization makes an important contribution and their effect onhealthy tissue should not be ignored.
http://ijsts.shirazu.ac.ir/article_2283_2992ee59058a49d3ec1f22fd0b115f35.pdf
BNCT
ionization effects
Lithium
Alpha
Protons
healthy tissue
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-17
32
3
175
181
10.22099/ijsts.2008.2284
2284
PUSHOUT CROSSED MODULES OF ALGEBROIDS
M. ALP
malp@dumlupinar.edu.tr
1
Dumlupinar University, Art and Science Faculty, Mathematics Department, Turkey
In 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.
http://ijsts.shirazu.ac.ir/article_2284_14eb922aae297750638a9f7e9c90e684.pdf
Crossed module
algebroids
pullback
action
pushout
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-17
32
3
183
190
10.22099/ijsts.2008.2285
2285
ON THE SYNCHRONIZATION OF COUPLED CHAOTIC SYSTEMS WITH ZERO LYAPUNOV EXPONENTS
G. H. ERJAEE
erjaee@shirazu.ac.ir
1
Mathematics Department, College of Sciences, Shiraz University, Shiraz, I. R. of Iran
The threshold of weak and strong synchronization in a coupled chaotic Gaussian map isdemonstrated by using the Pyragas’ terminology. However, Vieira and Lichtenberg have shown that thePyragas’ criteria for weak and strong synchronization cannot be used for all chaotic systems. In this articlewe demonstrated some interesting synchronization behavior of two coupled chaotic systems with some zeroand negative Lyapunov exponents. In such cases the various synchronization behaviors may also depend uponthe eigenvalues of a system obtained by subtracting two chaotic systems.
http://ijsts.shirazu.ac.ir/article_2285_30d30fad73f731c41f748e54c0261bbd.pdf
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-06
32
3
191
195
10.22099/ijsts.2008.2286
2286
POSITIVE LAGRANGE POLYNOMIALS
S. M. M. ZEKAVAT
zekavat@susc.ac.ir
1
SH. KHOSHDEL
2
Department of Mathematics, School of Science, Shiraz University, Shiraz, I. R. of Iran
Department of Mathematics, School of Science, Shiraz University, Shiraz, I. R. of Iran
In this paper we demonstrate the existence of a set of polynomials Pi , 1 i n , which arepositive semi-definite on an interval [a , b] and satisfy, partially, the conditions of polynomials found in theLagrange interpolation process. In other words, if a a1 an b is a given finite sequence of realnumbers, then Pi (a j ) ij (ij is the Kronecker delta symbol ) ; moreover, the sum of Pi 's is identically 1.
http://ijsts.shirazu.ac.ir/article_2286_17b9ff0f43b4590360384f1e66b815b0.pdf
Positive polynomials
Lagrange polynomials
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-01
32
3
197
205
10.22099/ijsts.2008.2287
2287
TRANSITIVITY OF -RELATION ON HYPERMODULES
S. M ANVARIYEH
anvariyeh@yazduni.ac.ir
1
S. MIRVAKILI
2
B. DAVVAZ
3
1Department of Mathematics, Yazd University, Yazd, I. R. of Iran
Department of Mathematics, Payame-Noor University, Yazd, I. R. of Iran
Department of Mathematics, Yazd University, Yazd, I. R. of Iran
¡V In this paper we consider a strongly regular relation ƒá on hypermodules so that the quotient is amodule (with abelian group) over a fundamental commutative ring. Also, we state necessary and sufficientconditions so that the relation ƒá is transitive, and finally we prove that ƒá is transitive on hypermodules.
http://ijsts.shirazu.ac.ir/article_2287_ebb4df6e3c31aabc39cf04e10695719b.pdf
– Hypermodule
hyperring
strongly regular relation
fundamental relation
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-01
32
3
207
213
10.22099/ijsts.2008.2288
2288
EFFECT OF THE EXTRINSIC AND TEMPORAL CARRIERS ON RADIATIVE RECOMBINATION OF III-NITRIDE NANOSTRUCTURES
M. ESMAEILI
moresm@walla.com
1
H. HARATIZADEH
2
M. GHOLAMI
3
B. MONEMAR
4
1Department of Basic Science, Islamic Azad University, Damghan Branch, Damghan, I. R. of Iran
Department of Physics, Shahrood University of Technology, 3619995161, P.O. Box 316, Shahrood, I. R. of Iran
Department of Basic Science, Islamic Azad University, Damghan Branch, Damghan, I. R. of Iran
Department of Physics, Chemistry and Biology, Linkoping University, SE-581 581 83 Linkoping, Sweden
Due to many important applications, the group III-Nitride semiconductors have recently attractedremarkable 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(PL) and time-resolved PL measurements. Extrinsic carriers come from Si doping in the barriers, whiletemporal carriers originate when the samples are excited by laser beam. The emission peaks of MQWs in PLspectra of the undoped and low-doped samples show a shift towards higher energy levels as excitationintensity increases, while the other samples do not exhibit such a phenomenon due to the dominance of theextrinsic carriers. The transient data confirm the results of the PL measurements.
http://ijsts.shirazu.ac.ir/article_2288_65f8a229a91f27726e27d06084d393f7.pdf
Nanostructures
photoluminescence (PL)
GaN/AlGaN multi quantum well
time Resolved PL (TRPL)
polarization fields
exciton
III-Nitride semiconductors
quantum well
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-01
32
3
215
219
10.22099/ijsts.2008.2289
2289
ON THE SOLVABILITY OF SOME OPERATOR-DIFFERENTIAL EQUATIONS IN COMPLEX DOMAIN
A. M. AKHMEDOV
ali_akhmedov@hotmail.com
1
Y. Y. MUSTAFAYEVA
2
Baku State University, Department of Mechanics and Mathematics, Z. Khalilov st., 23, P. O. Box Az-1148, Baku, Azerbaijan
Baku State University, Department of Mechanics and Mathematics, Z. Khalilov st., 23, P. O. Box Az-1148, Baku, Azerbaijan
In the present paper an operator-differential equation of second order in complex domain isconsidered when the coefficients have singularity of pole type at the point z=0. A theorem of existence of thesolution of the equation is proved and the spectral property of the solution is separately investigated when thecoefficients are spectral operators.
http://ijsts.shirazu.ac.ir/article_2289_7978064bea59623a9b77688ae5e5c00f.pdf
– Banach algebra
operator-differential equation
spectral operators
Boolean algebra
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-06
32
3
221
226
10.22099/ijsts.2008.2291
2291
CHARACTERIZATION OF A NEW PREPARED Li2B4O7: Mn DOSIMETER FOR γ- IRRADIATION HIGH-DOSE DOSIMETRY
M. SHARIFZADEH
msharifzadeh@aeoi.org.ir
1
R. GORJIFARD
2
Radiation Applications Research School, Nuclear Science &Technology Research Institute, P.O. Box 11365-3486, Tehran, I. R. of Iran
Radiation Applications Research School, Nuclear Science &Technology Research Institute, P.O. Box 11365-3486, Tehran, I. R. of Iran
A lithium borate thermoluminescence dosimeter with 0.3 wt% of manganese impurityconcentration was prepared for high dose levels in the range of 1-30 kGy for gamma irradiation applications.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.
http://ijsts.shirazu.ac.ir/article_2291_8f5d0a024271adf84081c7eebcb9b872.pdf
Dosimetry
Thermoluminescence
dose response
dose rate
glow curve
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2008-09-06
32
3
227
233
10.22099/ijsts.2008.2292
2292
DETERMINATION OF NEUTRON DETECTORS SHIELD USED FOR THE DETECTION OF LANDMINES
D. REZAEI OCHBELAGH
ddrezaey@yahoo.com
1
H. MIRI HAKIMABAD
2
R. IZADI NAJAFABADI
3
Department of Physics, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil, I. R. of Iran
Physics Department, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, I. R. of Iran
Physics Department, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, I. R. of Iran
As a result of being hydrogenous moderators, several landmine detection methods based onnuclear 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.
http://ijsts.shirazu.ac.ir/article_2292_b7436b2627122e4793c96a58afe9111d.pdf
MCNP
shielding
Detection
landmine
Am-Be
neutron backscattering
polyethylene
boric acid