2018-05-27T02:15:12Z
http://ijsts.shirazu.ac.ir/?_action=export&rf=summon&issue=470
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
DOSE RESPONSE OF IRRADIATED XRCT RADIOCHROMIC FILM
M. J.
BUTSON
T.
CHEUNG
P. K. N.
YU
H.
ALNAWAF
– 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.
radiochromic film
Gafchromic XRCT
radiation dosimetry
absorption spectra
2008
09
17
161
165
http://ijsts.shirazu.ac.ir/article_2282_010aa6b357cd1ef8efe369b2d6e8a932.pdf
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
STUDY ON IONIZATION EFFECTS PRODUCED BY NEUTRON INTERACTION PRODUCTS IN BNCT FIELD*
M. R
ESKANDARI
L.
REZAEE
S.
MOHAMMADI
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.
BNCT
ionization effects
Lithium
Alpha
Protons
healthy tissue
2008
09
17
167
173
http://ijsts.shirazu.ac.ir/article_2283_2992ee59058a49d3ec1f22fd0b115f35.pdf
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
PUSHOUT CROSSED MODULES OF ALGEBROIDS
M.
ALP
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.
Crossed module
algebroids
pullback
action
pushout
2008
09
17
175
181
http://ijsts.shirazu.ac.ir/article_2284_14eb922aae297750638a9f7e9c90e684.pdf
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
ON THE SYNCHRONIZATION OF COUPLED CHAOTIC SYSTEMS WITH ZERO LYAPUNOV EXPONENTS
G. H.
ERJAEE
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.
2008
09
17
183
190
http://ijsts.shirazu.ac.ir/article_2285_30d30fad73f731c41f748e54c0261bbd.pdf
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
POSITIVE LAGRANGE POLYNOMIALS
S. M. M.
ZEKAVAT
SH.
KHOSHDEL
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.
Positive polynomials
Lagrange polynomials
2008
09
06
191
195
http://ijsts.shirazu.ac.ir/article_2286_17b9ff0f43b4590360384f1e66b815b0.pdf
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
TRANSITIVITY OF -RELATION ON HYPERMODULES
S. M
ANVARIYEH
S.
MIRVAKILI
B.
DAVVAZ
¡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.
– Hypermodule
hyperring
strongly regular relation
fundamental relation
2008
09
01
197
205
http://ijsts.shirazu.ac.ir/article_2287_ebb4df6e3c31aabc39cf04e10695719b.pdf
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
EFFECT OF THE EXTRINSIC AND TEMPORAL CARRIERS ON RADIATIVE RECOMBINATION OF III-NITRIDE NANOSTRUCTURES
M.
ESMAEILI
H.
HARATIZADEH
M.
GHOLAMI
B.
MONEMAR
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.
Nanostructures
photoluminescence (PL)
GaN/AlGaN multi quantum well
time Resolved PL (TRPL)
polarization fields
exciton
III-Nitride semiconductors
quantum well
2008
09
01
207
213
http://ijsts.shirazu.ac.ir/article_2288_65f8a229a91f27726e27d06084d393f7.pdf
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
ON THE SOLVABILITY OF SOME OPERATOR-DIFFERENTIAL EQUATIONS IN COMPLEX DOMAIN
A. M.
AKHMEDOV
Y. Y.
MUSTAFAYEVA
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.
– Banach algebra
operator-differential equation
spectral operators
Boolean algebra
2008
09
01
215
219
http://ijsts.shirazu.ac.ir/article_2289_7978064bea59623a9b77688ae5e5c00f.pdf
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
CHARACTERIZATION OF A NEW PREPARED Li2B4O7: Mn DOSIMETER FOR γ- IRRADIATION HIGH-DOSE DOSIMETRY
M.
SHARIFZADEH
R.
GORJIFARD
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.
Dosimetry
Thermoluminescence
dose response
dose rate
glow curve
2008
09
06
221
226
http://ijsts.shirazu.ac.ir/article_2291_8f5d0a024271adf84081c7eebcb9b872.pdf
Iranian Journal of Science and Technology (Sciences)
Transaction A: Science
1028-6276
1028-6276
2008
32
3
DETERMINATION OF NEUTRON DETECTORS SHIELD USED FOR THE DETECTION OF LANDMINES
D.
REZAEI OCHBELAGH
H.
MIRI HAKIMABAD
R.
IZADI NAJAFABADI
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.
MCNP
shielding
Detection
landmine
Am-Be
neutron backscattering
polyethylene
boric acid
2008
09
06
227
233
http://ijsts.shirazu.ac.ir/article_2292_b7436b2627122e4793c96a58afe9111d.pdf