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Composites with superspherical inhomogeneities
, Article Philosophical Magazine Letters ; Volume 89, Issue 7 , 2009 , Pages 439-451 ; 09500839 (ISSN) ; Avazmohammadi, R ; Shodja, H. M ; Weng, G. J ; Sharif University of Technology
2009
Abstract
In contrast to the traditional study of composites containing ellipsoidal inclusions, we highlight some calculated results for the effective moduli when the inclusion shape can be described by the superspherical equation, [image omitted], such that when p = 2 it reduces to a sphere and when p it becomes a perfect cube. We consider the cases of both aligned and randomly oriented superspherical inclusions with isotropic, cubic, and transversely isotropic properties, and show how the shape parameter, p, affects the overall moduli of the composites during the spherical to cuboidal transition
Inclusion matrices and chains
, Article Journal of Combinatorial Theory. Series A ; Volume 115, Issue 5 , 2008 , Pages 878-887 ; 00973165 (ISSN) ; Khosrovshahi, G. B ; Maysoori, Ch ; Mohammad Noori, M ; Sharif University of Technology
2008
Abstract
Given integers t, k, and v such that 0 ≤ t ≤ k ≤ v, let Wt k (v) be the inclusion matrix of t-subsets vs. k-subsets of a v-set. We modify slightly the concept of standard tableau to study the notion of rank of a finite set of positive integers which was introduced by Frankl. Utilizing this, a decomposition of the poset 2[v] into symmetric skipless chains is given. Based on this decomposition, we construct an inclusion matrix, denoted by Wover(t, -) k (v), which is row-equivalent to Wt k (v). Its Smith normal form is determined. As applications, Wilson's diagonal form of Wt k (v) is obtained as well as a new proof of the well-known theorem on the necessary and sufficient conditions for...
On the inclusion ideal graph of a ring
, Article Electronic Notes in Discrete Mathematics ; Vol. 45, Issue , 2014 , pp. 73-78 ; ISSN: 15710653 ; Habibi, M ; Majidinya, A ; Manaviyat, R ; Sharif University of Technology
Abstract
The inclusion ideal graph of a ring R, denoted by In(R), is a graph whose vertices are all non-trivial left ideals of R and two distinct left ideals I and J are adjacent if and only if I⊆J or J⊆I. In this paper, we show that In(R) is not connected if and only if R≅M2(D) or D1×D2, for some division rings, D, D1 and D2. Moreover, if R is connected, then diam(In(R))≤3. We prove that if In(R) is a tree, then In(R) is a star graph or P4. Also, In(R) is a complete graph if and only if R is a uniserial ring. Next, it is shown that the inclusion ideal graph of Mn(D) for a division ring D and a natural number n>3 is not regular
A linear algebraic approach to orthogonal arrays and Latin squares
, Article Ars Combinatoria ; Volume 105 , 2012 , Pages 3-13 ; 03817032 (ISSN) ; Mahdian, M ; Mahmoodian, E. S ; Sharif University of Technology
2012
Abstract
To study orthogonal arrays and signed orthogonal arrays, Ray-Chaudhuri and Singhi (1988 and 1994) considered some module spaces. Here, using a linear algebraic approach we define an inclusion matrix and find its rank. In the special case of Latin squares we show that there is a straightforward algorithm for generating a basis for this matrix using the so-called intercalates. We also extend this last idea. Copyright
The inclusion ideal graph of rings
, Article Communications in Algebra ; Volume 43, Issue 6 , 2015 , Pages 2457-2465 ; 00927872 (ISSN) ; Habibi, M ; Majidinya, A ; Manaviyat, R ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
Let r be a ring with unity. the inclusion ideal graph of a ring R, denoted by In(R), is a graph whose vertices are all nontrivial left ideals of R and two distinct left ideals I and J are adjacent if and only if I ⊂ J or J ⊂ I. In this paper, we show that In(R) is not connected if and only if R ≅ M 2 (D) or D 1 × D 2 , for some division rings, D, D 1 and D 2 . Moreover, we prove that if In(R) is connected, then diam(In(R)) ≤3. It is shown that if In(R) is a tree, then In(R) is a caterpillar with diam(In(R)) ≤3. Also, we prove that the girth of In(R) belongs to the set {3, 6, ∞}. Finally, we determine the clique number and the chromatic...
Chrysin/β-cyclodextrin supramolecular system: a quantum mechanical investigation
, Article Journal of the Iranian Chemical Society ; Volume 15, Issue 10 , 2018 , Pages 2401-2410 ; 1735207X (ISSN) ; Gerayeli, N ; Tafazzoli, M ; Sharif University of Technology
Abstract
Chrysin is a bioflavonoid which possesses a wide range of important biological activities. In present study, we used a quantum mechanical approach to shed light on the antioxidant ability and antioxidant mechanism of chrysin to scavenge hydroxyl radical (˙OH) in solution phase. The analysis of the theoretical bond dissociation enthalpy (BDE) values and spin density of the radicals to determine the delocalization possibilities at B3LYP/6-311++G** level clearly shows the importance of the A-ring and the 7-OH group in antioxidant reactivity. In the next step, the inclusion of chrysin with β-CD has been investigated extensively using theoretical methods. Density functional theory (M05-2X)...
Interacting cracks and ellipsoidal inhomogeneities by the equivalent inclusion method
, Article Journal of the Mechanics and Physics of Solids ; Volume 51, Issue 5 , 2003 , Pages 945-960 ; 00225096 (ISSN) ; Rad, I. Z ; Soheilifard, R ; Sharif University of Technology
2003
Abstract
Based on the Eshelby's equivalent inclusion method (EIM) and Hill's theorem on discontinuities of elastic fields across the interfaces, a theory for the determination of the stress intensity factors (SIFs) of arbitrarily oriented interacting cracks under non-uniform far-field applied stress (strain) is developed. As shown in this investigation the EIM proposed by Moschovidis and Mura can be extended for treatment of such problems, but their formulations are quite cumbersome and computationally inefficient. An alternative analytical approach is proposed that is computationally more efficient, and unlike the method of Moschovidis and Mura can easily handle complex problems of interacting...
Tensor spherical harmonics theories on the exact nature of the elastic fields of a spherically anisotropic multi-inhomogeneous inclusion
, Article Journal of the Mechanics and Physics of Solids ; Volume 61, Issue 4 , April , 2013 , Pages 1124-1143 ; 00225096 (ISSN) ; Khorshidi, A ; Sharif University of Technology
2013
Abstract
Eshelby's theories on the nature of the disturbance strains due to polynomial eigenstrains inside an isotropic ellipsoidal inclusion, and the form of homogenizing eigenstrains corresponding to remote polynomial loadings in the equivalent inclusion method (EIM) are not valid for spherically anisotropic inclusions and inhomogeneities. Materials with spherically anisotropic behavior are frequently encountered in nature, for example, some graphite particles or polyethylene spherulites. Moreover, multi-inclusions/inhomogeneities/ inhomogeneous inclusions have abundant engineering and scientific applications and their exact theoretical treatment would be of great value. The present work is devoted...
Determination of stress distribution around two Carbon Nonotubes embedded in infinite metal matrix using nonlocal theory of elasticity
, Article Applied Mechanics and Materials, 29 July 2011 through 31 July 2011 ; Volume 110-116 , July , 2012 , Pages 1696-1700 ; 16609336 (ISSN) ; 9783037852620 (ISBN) ; Naghdabadi, R ; Sharif University of Technology
Abstract
Stress distribution in Carbon Nanotube (CNT) reinforced composites is studied using nonlocal theory of elasticity. Two nearby CNTs are modeled as two circular inclusions embedded in an infinite elastic medium, and classical stresses are obtained using the complex stress potential method. Nonlocal stresses are calculated using nonlocal integral elasticity equation. Effects of the distance between CNTs as well as effects of the nonlocal parameters on the stress distribution and stress concentration are studied. For unit normal stress at infinity, stress at the interface of the CNT and matrix increases from 0.1 for classical analysis to 0.85 for nonlocal analysis. Furthermore, when two CNTs...
Electroelastic fields in interacting piezoelectric inhomogeneities by the electromechanical equivalent inclusion method
, Article Smart Materials and Structures ; Volume 19, Issue 3 , 2010 ; 09641726 (ISSN) ; Kargarnovin, M. H ; Hashemi, R ; Sharif University of Technology
2010
Abstract
Consider two piezoelectric ellipsoidal inhomogeneities of arbitrary size, orientation and material constants, which in turn are surrounded by an infinite isotropic medium. The system under consideration is subjected to far-field non-uniform electromechanical loadings. Based on the extension of the electromechanical equivalent inclusion method (EMEIM), the present paper develops a unified solution for determination of the associated electroelastic fields in the vicinity of interacting inhomogeneities. Accordingly, each of the piezoelectric inhomogeneities is broken down into two equivalent inclusions with proper polynomial eigenstrains and eigenelectric fields. The robustness and efficacy of...
Removal of Non-Metallic Inclusions from Steel by Electromagnetic Levitation Melting in a Slag
, M.Sc. Thesis Sharif University of Technology ; Halali, Mohammad (Supervisor)
Abstract
In this study, industrial steel (DIN 17135) underwent a new purification process with the aim of removing non-metallic inclusions and producing clean steel. Samples of steel were levitated in synthetic slag from the CaO-CaF2-Al2O3 system by an electromagnetic field. The effect of time, temperature and slag composition factors on the inclusions content of sample has been investigated. The images of the optical microscope were evaluated according to the ASTM E 45 standard, which according to the extracted results, the removal process was done to the desired extent. On the other hand, as the time and temperature of the process and the weight percentage of CaF2 increase, the number and size of...
Metallography and microstructure interpretation of some archaeological tin bronze vessels from Iran
, Article Materials Characterization ; Vol. 97 , November , 2014 , pp. 74-82 ; Davami, P ; Sharif University of Technology
Abstract
Archaeological excavations in western Iran have recently revealed a significant Luristan Bronzes collection from Sangtarashan archaeological site. The site and its bronze collection are dated to Iron Age II/III of western Iran (10th-7th century BC) according to archaeological research. Alloy composition, microstructure and manufacturing technique of some sheet metal vessels are determined to reveal metallurgical processes in western Iran in the first millennium BC. Experimental analyses were carried out using Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy and Optical Microscopy/Metallography methods. The results allowed reconstructing the manufacturing process of bronze...
Ellipsoidal domain with piecewise nonuniform eigenstrain field in one of joined isotropic half-spaces
, Article Journal of Elasticity ; Volume 98, Issue 2 , 2010 , Pages 117-140 ; 03743535 (ISSN) ; Hashemi, R ; Shodja, H. M ; Kargarnovin, M. H ; Sharif University of Technology
2010
Abstract
Consider an arbitrarily oriented ellipsoidal domain near the interface of an isotropic bimaterial space. It is assumed that a general class of piecewise nonuniform dilatational eigenstrain field is distributed within the ellipsoidal domain. Two theorems relevant to prediction of the nature of the induced displacement field for the interior and exterior points of the ellipsoidal domain are stated and proved. As a resultant the exact analytical expression of the elastic fields are obtained rigorously. In this work a new Eshelby-like tensor, A is introduced. In particular, the closed-form expressions for A associated with the interior points of spherical and cylindrical inclusion are derived....
Removal of non-metallic inclusions from nickel base superalloys by electromagnetic levitation melting in a slag
, Article Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science ; Volume 49, Issue 1 , February , 2018 , Pages 61-68 ; 10735615 (ISSN) ; Halali, M ; Sharif University of Technology
Springer Boston
2018
Abstract
Samples of INCONEL 718 were levitated and melted in a slag by the application of an electromagnetic field. The effects of temperature, time, and slag composition on the inclusion content of the samples were studied thoroughly. Samples were compared with the original alloy to study the effect of the process on inclusions. Size, shape, and chemical composition of remaining non-metallic inclusions were investigated. The samples were prepared by Standard Guide for Preparing and Evaluating Specimens for Automatic Inclusion Assessment of Steel (ASTM E 768-99) method and the results were reported by means of the Standard Test Methods for Determining the Inclusion Content of Steel (ASTM E 45-97)....
Experimental Study of the β-CD-g-PG Hybrid Nanostructure On Phase Solubilityof Hydrophobic Drug
, M.Sc. Thesis Sharif University of Technology ; Saifkordi, Aliakbar (Supervisor) ; Vossoughi, Manouchehr (Supervisor)
Abstract
Some widely used drugs such as paclitaxel (PTX) are poorly water soluble. The clinical use of PTX with solubilizer causes side effects. These problems limited its application in treatments. In this work has been studied the effect of β-CD-g-PG (HPCD) hybrid nanomaterials, conjugated PG branches onto β-CD core, on the water solubility of PTX. First HPCD has been synthesized. Then the inclusion complex of PTX with HPCD was prepared. The inclusion complex efficiency for PTX:HPCD complex in 1:25 mole ratio was 87%. Then solubility of PTX with HPCD in water has been determined, showing Ap type phase solubility diagram. Then stability constants were calculated. The first order and second order...
Investigation of phase Solubility Enhancement of Paclitaxel by Inclusion Complex of drug in B-CD-g-PG
, M.Sc. Thesis Sharif University of Technology ; Yaghmaei, Soheyla (Supervisor) ; Vossoughi, Manoochehr (Supervisor) ; Kazemi Daliri, Akhtarolmoluk (Supervisor)
Abstract
Paclitaxel is using as a drug against breast and ovary cancers. Although paclitaxel has high biologic activity, it has very poor solubility in water the same as some other drugs. Since drugs should be solved in water to be absorbed by the body, for absorb enhancement, we should use carriers which includes both polar and non polar sites.
Beta-Cyclodextrin which has this feature is capable for producing inclusion complex in its hydrophobic pores with non polar materials. In this project, by adding polymeric polyglycerol branches on Beta-Cyclodextrin, a polymeric nanostructure has been developed to enhance water solubility in comparison with pure Beta-Cyclodextrin.
Study on producing...
Beta-Cyclodextrin which has this feature is capable for producing inclusion complex in its hydrophobic pores with non polar materials. In this project, by adding polymeric polyglycerol branches on Beta-Cyclodextrin, a polymeric nanostructure has been developed to enhance water solubility in comparison with pure Beta-Cyclodextrin.
Study on producing...
Design and Synthesis of a Novel Nanomaterial as a Carrier of a Hydrophobe drug in an Inclusion Complex based on Cychlodextrin
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Manouchehr (Supervisor) ; Kazemi, Akhtarolmolouk (Supervisor)
Abstract
Paclitaxel is used as a drug against breast and ovarian cancers. Although paclitaxel has high biologic activity, it has very pour solubility in water like some other drugs. Since drugs should be solved in water to be absorbed by the body, for absorb enhancement, we should use carriers which includes both polar and non polar sites. eta-Cyclodextrin which has this feature is capable for producing inclusion complex in its hydrophobic pores with non polar materials. In this project by adding polymeric polyacrylamide branches on beta-Cyclodextrin, polymeric nano structure has been developed to enhance water solubility in comparison with pure beta-Cyclodextrin. Study on producing polymeric nano...
Effect of Titanium on the Microstructure and Sour Environment Cracking Resistance of API 5L-X70 SAW Weld Metals
, Ph.D. Dissertation Sharif University of Technology ; Kokabi, Amir Hossein (Supervisor) ; Dolati, Abolghasem (Supervisor)
Abstract
In this research, the effect of addition of titanium to the weld metal of API 5L-X70 steel at two levels of manganese (1.4 and 2.0%) was studied; and the microstructure, mechanical properties, and hydrogen cracking resistance of the weld metals were investigated carefully. The submerged arc welding method was used for preparation of the welds and the metallographic test, hardness test, longitudinal tension test, Charpy V-notch impact test, HIC and SSC evaluation tests and thermal desorption spectroscopy test were done for each weld. The results showed that the addition of titanium to the weld metal increased formation of acicular ferrite; therefore, toughness of the welds was increased...
Investigation of Inclusion Behavior in Molten Steel in Contact with Slag in the Presence of Electromagnetic Field
, M.Sc. Thesis Sharif University of Technology ; Halali, Mohammad (Supervisor)
Abstract
Much research has been done in the electromagnetic levitation process, but there is not any information about carrying out this process to refine steel continuously. In this study inclusion behavior of molten steel in contact with slag, in the presence of an electeomagnetic field, has been investigated. The steel sample, in an elliptical section, was levitated in an electromagnetic field, in a chamber containing slag consisting of CaF2-Al2O3-CaO, in order to achieve a continuous process, and changes in time, temperature and slag composition parameters in this process were studied. According to ASTM E45 standard, after performing metallographic process on melted samples, using light...
Inclusion problems associated with thin fcc films: linkage between eigenstrain and inter-atomic potential
, Article Mechanics of Materials ; Volume 39, Issue 8 , 2007 , Pages 803-818 ; 01676636 (ISSN) ; Pahlevani, L ; Hamed, E ; Sharif University of Technology
2007
Abstract
Often, during fabrication of thin films on substrates, different types of defects may be introduced into the films. Recently, the determination of the elastic fields due to the self-assembly of quantum dots or strained islands in thin films has been of major concern. In the micromechanical studies, such strained islands are modeled by inclusions. This paper aims to develop a theory pertaining to the presence of nano-inclusions of various geometries within thin films having face centered cubic (fcc) structure. To this end, the notion of eigenstrain is combined with a many body inter-atomic potential suitable for fcc crystals. The interaction between atoms is modeled via Sutton-Chen (SC)...