2007
18
4
4
0
1

Synthesis of Binary TiSi Mixed Oxides Nanoparticles with Rutile Structure as Selective Catalyst for Epoxidation of Alkenes
https://jsciences.ut.ac.ir/article_35065.html
1
The nanoparticles of TiSi mixed oxides (NTSO) with Rutile structure were prepared by solgel method in a mixture of alcohol and water as solvent. The solid product was characterized by XRD, FTIR, SEM, TEM, UV, TGA and laser Raman spectroscopy. The catalytic activity of NTSO (510 nm) was investigated in the epoxidation of cis stilbene, trans stilbene, and norbornene by using oxidants such as tertbutylhydroperoxide (TBHP), molecular oxygen (O2)/isobutyraldehyde (IBA) and hydrogen peroxide (H2O2). It was found that epoxides of transstilbene andnorbornenewereformedquantitativelywiththegreenH2O2oxidantduring12h.
0

303
395


F.
Farzaneh
Department of Chemistry, Alzahra University, Vanak, Tehran, Islamic Republic of Iran
Iran
Epoxidation
Alkenes
TiSi mixed oxides
nanoparticles
Heterogeneous catalysis
1

Complete Convergence and Some Maximal Inequalities for Weighted Sums of Random Variables
https://jsciences.ut.ac.ir/article_35073.html
1
Let be a sequence of arbitrary random variables with and , for every and be an array of real numbers. We will obtain two maximal inequalities for partial sums and weighted sums of random variables and also, we will prove complete convergence for weighted sums , under some conditions on and sequence .
0

311
316


M.
Amini
Department of Statistics, Faculty of Mathematical Sciences, Ferdowsi University
of Mashhad, Mashhad, Islamic Republic of Iran
Iran
1

A Computational Meshless Method for Solving Multivariable Integral Equations
https://jsciences.ut.ac.ir/article_35075.html
1
In this paper we use radial basis functions to solve multivariable integral equations. We use collocation method for implementation. Numerical experiments show the accuracy of the method.
0

317
321


E.
Babolian
Department of Mathematics, Teacher Training University, Tehran, Islamic Republic of Iran
Iran
1

On the UWPF Acts over Monoids
https://jsciences.ut.ac.ir/article_35076.html
1
Valdis Laan in [5] introduced an extension of strong flatness which is called weak pullback flatness. In this paper we introduce a new property of acts over monoids, called UWPF which is an extension of weak pullback flatness and give a classification of monoids by this property of their acts and also a classification of monoids when this property of acts implies others. We also show that regularity and strong faithfulness of acts both imply UWPF. An equivalent of that over monoids for which torsion freeness implies UWPF is given too.
0

323
328


A.
Golchin
Department of Mathematics, University of Sistan and Baluchestan, Zahedan, Islamic Republic of Iran
Iran
UWPF
Strongly faithful
Regular
1

Nonlinear TwoPhase Stefan Problem
https://jsciences.ut.ac.ir/article_35077.html
1
In this paper we consider a nonlinear twophase Stefan problem in onedimensional space. The problem is mapped into a nonlinear Volterra integral equation for the free boundary.
0

329
337


K.
Ivaz
Department of Mathematics, University of Tabriz, Tabriz, Islamic Republic of Iran
Iran
Free boundary problems
integral equation
1

Derivations on Certain Semigroup Algebras
https://jsciences.ut.ac.ir/article_35078.html
1
In the present paper we give a partially negative answer to a conjecture of Ghahramani, Runde and Willis. We also discuss the derivation problem for both foundation semigroup algebras and Clifford semigroup algebras. In particular, we prove that if S is a topological Clifford semigroup for which Es is finite, then H1(M(S),M(S))={0}.
0

339
345


M.
Lashkarizadeh Bami
Department of Mathematics, University of Isfahan, Isfahan, Islamic Republic of Iran
Iran
Foundation semigroup
Semigroup algebra
Derivation
First order cohomology
Clifford semigroup
1

Modified Progressive TypeII Censoring Procedure in LifeTesting under the Weibull Model
https://jsciences.ut.ac.ir/article_35079.html
1
In this paper we introduce a new scheme of censoring and study it under the Weibull distribution. This scheme is a mixture of progressive Type II censoring and self relocating design which was first introduced by Srivastava [8]. We show the superiority of this censoring scheme (PSRD) relative to the classical schemes with respect to “asymptotic variance”. Comparisons are also made with respect to the total expected time under experiment (TETUE) as an important feature of time and cost saving. These comparisons show that TETUE(SRD) < TETUE(PSRD) < TETUE(PC2) if 0 < β < 1, TETUE(PSRD) = TETUE(SRD) < TETUE(PC2) if β = 1 and TETUE(PSRD) is the best among all the designs if β = 2 (Rayleigh distribution case).
0

347
354


M.
Khodadadi
Department of Statistics, Faculty of Mathematical Sciences, Shahid Beheshti
University, Tehran, Islamic Republic of Iran
Iran
Asymptotic variance
Fisher information matrix
Maximum likelihood
Self relocating design (SRD)
Total expected time under experiment
1

Essentially Retractable Modules
https://jsciences.ut.ac.ir/article_35080.html
1
We call a module essentially retractable if HomR for all essential submodules N of M. For a right FBN ring R, it is shown that: (i) A nonzero module is retractable (in the sense that HomR for all nonzero ) if and only if certain factor modules of M are essentially retractable nonsingular modules over R modulo their annihilators. (ii) A nonzero module is essentially retractable if and only if there exists a prime ideal such that HomR. Over semiprime right nonsingular rings, a nonsingular essentially retractable module is precisely a module with nonzero dual. Moreover, over certain rings R, including right FBN rings, it is shown that a nonsingular module M with enough uniforms is essentially retractable if and only if there exist uniform retractable Rmodules and Rhomomorphisms with .
0

355
360


M.R.
Vedadi
Department of Mathematical Sciences, Isfahan University of Technology,
Isfahan 8415683111, Islamic Republic of Iran
Iran
Dual module
Essentially retractable
Homorelated