eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2007-08-11
31
2
151
162
10.22099/ijsts.2007.2324
2324
COMBINED HEAT AND MASS TRANSFER IN MHD FREE CONVECTION FROM A WEDGE WITH OHMIC HEATING AND VISCOUS DISSIPATION IN THE PRESENCE OF SUCTION OR INJECTION
R. KANDASAMY
kandan_kkk@yahoo.co
1
I. HASHIM
2
A. B. KHAMIS
3
I. MUHAIMIN
4
Centre for Science Studies, University of Tun Hussein Onn, Malaysia, 86400 Parit Raja, Batu Pahat Johor, Malaysia
School of Mathematical Sciences, University of Kebangsaan, Malaysia, 43600 UKM Bangi Selangor, Malaysia
Centre for Science Studies, University of Tun Hussein Onn, Malaysia, 86400 Parit Raja, Batu Pahat Johor, Malaysia
Centre for Science Studies, University of Tun Hussein Onn, Malaysia, 86400 Parit Raja, Batu Pahat Johor, Malaysia
The problem of combined heat and mass transfer of an electrically conducting fluid in MHD<br />natural convection adjacent to a vertical surface is analyzed, taking into account the effects of Ohmic heating<br />in the presence of suction or injection. An approximate numerical solution for the steady laminar boundarylayer<br />flow over a wall of the wedge in the presence of species concentration and mass diffusion has been<br />obtained by solving the governing equations using the numerical technique. The fluid is assumed to be<br />viscous and incompressible. Numerical calculations are carried out for different values of dimensionless<br />parameters and an analysis of the results obtained shows that the flow field is influenced appreciably by the<br />magnetic effect, the buoyancy ratio between species and thermal diffusion and suction/injection at the wall<br />surface. Effects of these major parameters on transport behaviors are investigated methodically and typical<br />results are illustrated to reveal the tendency of the solutions. Representative results are presented for the<br />velocity, temperature, and concentration distributions, as well as the local skin-friction coefficient and skin<br />friction.
http://ijsts.shirazu.ac.ir/article_2324_f85ca468fa7afed222d5fef73f4909a2.pdf
Buoyancy ratio
Ohmic heating
Boussinesq fluid
MHD boundary layer flow and suction/injection at
the wall of the wedge
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2007-08-11
31
2
163
170
10.22099/ijsts.2007.2325
2325
ON PROBLEMS REDUCING TO THE GOURSAT PROBLEM FOR A FOURTH ORDER EQUATION
A. MAHER
a_maher69@yahoo.com
1
YE. A. UTKINA
2
Department of Mathematics, Faculty of Science, Assiut University, 71516, Egypt
Department of Differential Equations, Kazan State University, 18 Kremlyovskaya St., Kazan, 420008, Russia
In this paper, we investigate some problems which can be reduced to the Goursat problem for a<br />fourth order equation. Some results and theorems are given concerning the existence and uniqence for the<br />solution of the suggested problem.
http://ijsts.shirazu.ac.ir/article_2325_67776a597b75725198c49b9e4d70f7d9.pdf
Fourth order of partial differential equations
goursat problem
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2007-08-11
31
2
171
175
10.22099/ijsts.2007.2326
2326
HIGH SPIN STATES IN 191OS
S. MOHAMMADI
mohammadi@pnu.ac.ir
1
ZS. PODOLYAK
2
Physics Department, Payam Noor University, Mashhad 91735, I. R. of Iran
Department of Physics, University of Surrey, Guildford, GU2 7XH, UK
High spin states in the neutron rich nucleus 191Os has been populated for the first time using the<br />82Se+192Os deep-inelastic reaction at 460 MeV beam energy using the ALPI accelerators at the Laboratory<br />Nazionali di Legnaro, Italy. High fold γ-γ coincidences were acquired with the 4π spectrometer GASP<br />detector array, consisting of 40 Compton-suppressed, large-volume germanium detectors with an inner ball<br />consisting of 80 BGO crystals acting as a multiplicity filter and a total-energy spectrometer. The new<br />discovered level scheme is extended up to spin 19/2+. The observed structure is interpreted as fragments of a<br />rotational band built on single neutron configuration {11/2+ [615]} according to a Nilsson deformed shell<br />model.
http://ijsts.shirazu.ac.ir/article_2326_9f20d131682480774cd48e1443251f9f.pdf
Deep-inelastic Reaction
Rotational Band
High Spin States
Deformed Shell Model
Gamma-gamma
Coincidences
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2007-08-11
31
2
177
181
10.22099/ijsts.2007.2327
2327
ON THE HELICES IN THE GALILEAN SPACE G3
A. O. OGRENMIS
aogrenmis@firat.edu.tr
1
E. ERGUT
2
M. BEKTAS
3
Department of Mathematics, Firat University, 23119, Elazig, Turkey
Department of Mathematics, Firat University, 23119, Elazig, Turkey
Department of Mathematics, Firat University, 23119, Elazig, Turkey
T. Ikawa obtained an ordinary differential equation for the circular helix. Recently, the helix have<br />been investigated by many differential geometers such as T. Ikawa, H. Balgetir, M. Bektas, M. Ergut, N.<br />Ekmekci and H. H. Hacısalihoglu. In this paper, making use of this author’s methods, we obtained<br />characterizations of helix for a curve with respect to the Frenet frame in 3-dimensional Galilean space G3.
http://ijsts.shirazu.ac.ir/article_2327_b01dbc7305fb6076018322b51bdadd31.pdf
Galilean Space
Helix
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2007-08-11
31
2
183
188
10.22099/ijsts.2007.2328
2328
DOUBLE SEQUENCE SPACES DEFINED BY ORLICZ FUNCTIONS
E. SAVAS
ekremsavas@yahoo.com & esavas@iticu.edu.tr
1
R. F. PATTERSON
rpatters@unf.edu
2
Istanbul Ticaret University, Department of Mathematics, Uskudar, Istanbul, Turkey
University of North Florida, Building 11 Jacksonville, Florida 32224, USA
In this paper we introduce some new double sequence spaces using the Orlicz function and<br />examine some properties of the resulting sequence spaces.
http://ijsts.shirazu.ac.ir/article_2328_6f2c9f3812a99498fab81db1a379565b.pdf
Double sequences
P-convergent
Orlicz functions
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2007-08-11
31
2
189
197
10.22099/ijsts.2007.2329
2329
SEQUENTIAL ESTIMATION IN A SUBCLASS OF EXPONENTIAL FAMILY UNDER WEIGHTED SQUARED ERROR LOSS
N. NEMATOLLAHI
nematollahi@atu.ac.ir
1
M. JAFARI JOZANI
2
N. MAHLOOJI
3
Department of Statistics, Faculty of Economics, Allameh Tabataba'i University, Tehran, I. R. of Iran
Department of Statistics, Faculty of Economics, Allameh Tabataba'i University, Tehran, I. R. of Iran
Department of Statistics, Faculty of Economics, Allameh Tabataba'i University, Tehran, I. R. of Iran
In a subclass of the scale-parameter exponential family, we consider the sequential point<br />estimation of a function of the scale parameter under the loss function given as the sum of the weighted<br />squared error loss and a linear cost. For a fully sequential sampling scheme, second order expansions are<br />obtained for the expected sample size as well as for the regret of the procedure. The former researches on<br />Gamma and Exponential distributions can be deduced from our general results.
http://ijsts.shirazu.ac.ir/article_2329_ef4dc04839d1c9f19b144aa44df81031.pdf
Sequential estimation
stopping rule
regret analysis
exponential family
transformed chi-square
distribution
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2007-08-11
31
2
199
206
10.22099/ijsts.2007.2330
2330
MINIMIZING LOSS PROBABILITY IN QUEUING SYSTEMS WITH HETEROGENEOUS SERVERS
V. SAGLAM
vsaglam@omu.edu.tr
1
A. SHAHBAZOV
2
Department of Statistic, Faculty of Arts and Sciences, Ondokuz Mayis University, Kurupelit, 55139-Samsun, Turkey,
Department of Statistic, Faculty of Arts and Sciences, Ondokuz Mayis University, Kurupelit, 55139-Samsun, Turkey
The probability of losing a customer in M/G/n/0 and GI/M/n/0 loss queuing systems with<br />heterogeneous servers is minimized. The first system uses a queue discipline in which a customer who arrives<br />when there are free servers chooses any one of them with equal probability, but is lost otherwise. Provided<br />that the sum of the servers rates are fixed, loss probability in this system attains minimum value when all the<br />service rates are equal. The second system uses queue discipline, in which a customer who enters into the<br />system is assigned to the server with the lowest number. Loss probability in this system takes the minimum<br />value in the case when the fastest server rule is used in which an incoming customer is served by the free<br />server with the shortest mean service time. If the mean of the arrival distribution is fixed, then loss probability<br />is minimized by deterministic arrival distribution
http://ijsts.shirazu.ac.ir/article_2330_6901ed3bf3527b64512d59331e0f5239.pdf
Service rate
Erlang’s loss formula
heterogeneous servers
loss probability
recurrent input
exponential
server
overflow distribution
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2007-08-11
31
2
207
212
10.22099/ijsts.2007.2331
2331
STEINER FORMULA AND HOLDITCH-TYPE THEOREMS FOR HOMOTHETIC LORENTZIAN MOTIONS
S. YUCE
sayuce@yildiz.edu.tr
1
N. KURUOGLU
2
Yıldız Technical University, Faculty of Arts and Science, Department of Mathematics, Esenler, 34210, Istanbul, Turkey,
University of Bahcesehir, Faculty of Arts and Science, Department of Mathematics and Computer Sciences, Besiktas 34100, Istanbul, Turkey
The present paper is concerned with the generalization of the Holditch Theorem under oneparameter<br />homothetic motion on Lorentzian planes. In this paper, for the homothetic Lorentzian motion, we<br />expressed the Steiner formula. Furthermore, we present the Holditch-Type Theorems.
http://ijsts.shirazu.ac.ir/article_2331_e2decd10f598924fc8320c13325124c7.pdf
Holditch Theorem
Steiner formula
lorentzian plane
homothetic motion
eng
Springer
Iranian Journal of Science and Technology (Sciences)
1028-6276
1028-6276
2007-08-11
31
2
213
217
10.22099/ijsts.2007.2332
2332
A BOUNDARY INTEGRAL MODEL FOR SIMULATING SPILLING BREAKERS
S. A. AZARMSA
azarmsaa@modares.ac.ir,
1
Faculty of Marine Sciences, Tarbiat Modares University, Tehran, I. R. of Iran
A boundary integral method is used to simulate spilling breakers. The bottom is also included in<br />the introduced closed boundary and the problem is directly solved in the physical plane. The method has been<br />shown to be remarkably stable, and no numerical instability has occurred in any of the calculations. The<br />results reveal that both the momentum and total energy are almost constant in time during the simulation<br />period. As a result, the breaking process of a spilling breaker is fairly well simulated.
http://ijsts.shirazu.ac.ir/article_2332_e1952cb184e26c8f0bdeb548cb62fafb.pdf
Breaking waves
Numerical simulation
spilling
Cauchy’s integral theorem