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81.
Zarghi A Hajimahdi Z Mohebbi S Rashidi H Mozaffari S Sarraf S Faizi M Tabatabaee SA Shafiee A 《Chemical & pharmaceutical bulletin》2008,56(4):509-512
A new series of 2-substituted-5-[2-(2-halobenzyloxy)phenyl]-1,3,4-oxadiazoles was designed and synthesized as anticonvulsant agents. Electroshock and pentylenetetrazole-induced lethal convulsion tests showed that the introduction of an amino group at position 2 of 1,3,4-oxadiazole ring and a fluoro substituent at ortho position of benzyloxy moiety had the best anticonvulsant activity. Our results showed that this effect is mediated through benzodiazepine receptors mechanism. 相似文献
82.
Arsou Arimi Mehrdad Farhadian Ali Reza Solaimany Nazar Maryam Homayoonfal 《Research on Chemical Intermediates》2016,42(5):4021-4040
In the current study, a nanophotocatalyst doped with of TiO2 and Fe2O3 nanoparticles supported on Iranian clinoptilolite was synthesized and characterized by XRD, XRF, SEM, and EDX analyses. The results suggested the successful loading of TiO2 and Fe2O3 nanoparticles onto the surface of clinoptilolite. The SEM images confirmed the average size of nanoparticles deposited on zeolite, which was about 20–40 nm. Furthermore, application of the synthesized photocatalyst in photocatalytic degradation of Acid Black 172 dye was studied using the Taguchi method and the chosen parameters were as follows: pH (2–7), dye concentration (50–200 mg/l), irradiation time (30–120 min), and catalyst dosage (0.5–1.5 g/l). The results indicate that dye concentration, pH, and irradiation time are respectively the most effective factors in these experiments while with the minimum dosage of the catalyst (0.5 g/l), up to 90 % removal efficiency could be achieved. The optimum value for each parameter was pH = 2, dye concentration = 50 mg/l, catalyst dosage = 1 g/l and irradiation time = 60 min, and the dye removal efficiency reached up to 100 % at these optimal conditions. Furthermore, after five-times recycling and reusing the catalyst, the efficiency of the photocatalytic degradation was reduced from 91.5 to 65.9 %, which is still an acceptable value. 相似文献
83.
Effect of nano‐modified SiO2/Al2O3 mixed‐matrix micro‐composite fillers on thermal,mechanical, and tribological properties of epoxy polymers
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Sadasivan S. Vaisakh Abdul Azeez Peer Mohammed Mehrdad Hassanzadeh Jean F. Tortorici Renaud Metz Solaiappan Ananthakumar 《先进技术聚合物》2016,27(7):905-914
Thermo‐mechanically durable industrial polymer nanocomposites have great demand as structural components. In this work, highly competent filler design is processed via nano‐modified of micronic SiO2/Al2O3 particulate ceramics and studied its influence on the rheology, glass transition temperature, composite microstructure, thermal conductivity, mechanical strength, micro hardness, and tribology properties. Composites were fabricated with different proportions of nano‐modified micro‐composite fillers in epoxy matrix at as much possible filler loadings. Results revealed that nano‐modified SiO2/Al2O3 micro‐composite fillers enhanced inter‐particle network and offer benefits like homogeneous microstructures and increased thermal conductivity. Epoxy composites attained thermal conductivity of 0.8 W/mK at 46% filler loading. Mechanical strength and bulk hardness were reached to higher values on the incorporation of nano‐modified fillers. Tribology study revealed an increased specific wear rate and decreased friction coefficient in such fillers. The study is significant in a way that the design of nano‐modified mixed‐matrix micro‐composite fillers are effective where a high loading is much easier, which is critical for achieving desired thermal and mechanical properties for any engineering applications. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Particle swarm optimization (PSO) is an evolutionary, easy-to-implement technique to design optical diffraction gratings. Design of reflection and transmission guided-mode resonance (GMR) grating filters using PSO is reported. The spectra of the designed filters are in good agreement with the design targets in a reasonable computation time. Also, filters are designed with a genetic algorithm (GA) and the results obtained by the GA and PSO are compared. 相似文献
87.
Mehrdad Pourayoubi James A. Golen Mahnaz Rostami Chaijan Vladimir Divjakovic Monireh Negari Arnold L. Rheingold 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(5):m160-m164
In the new tin(IV) and copper(II) complexes, cis‐dichlorido‐trans‐dimethyl‐cis‐bis(N,N′,N′′‐tricyclohexylphosphoric triamide‐κO)tin(IV), [Sn(CH3)2Cl2(C18H36N3OP)2], (I), and trans‐diaquabis(N,N′,N′′‐tricyclohexylphosphoric triamide‐κO)copper(II) dinitrate–N,N′,N′′‐tricyclohexylphosphoric triamide (1/2), [Cu(C18H36N3OP)2(H2O)2](NO3)2·2C18H36N3OP, (II), the N,N′,N′′‐tricyclohexylphosphoric triamide (PTA) ligands exist as hydrogen‐bonded dimers via P=O...H—N interactions around the metal center. The asymmetric unit in (I) consists of one complete complex molecule located on a general position. The SnIV coordination geometry is octahedral with two cis hydrogen‐bonded PTA ligands, two cis chloride ligands and two trans methyl groups. The asymmetric unit in (II) contains one half of a [Cu(PTA)2(H2O)2]2+ dication on a special position (site symmetry for the Cu atom), one nitrate anion and one free PTA molecule, both on general positions. The complex adopts a square‐planar trans‐[CuO2O2] coordination geometry, with the CuII ion coordinated by two PTA ligands and two water molecules. Each of the noncoordinated PTA molecules is hydrogen bonded to a neighboring coordinated PTA molecule and an adjacent water molecule; the phosphoryl O atom acts as a double‐H‐atom acceptor. The P atoms in the PTA ligands of both complexes and in the noncoordinated hydrogen‐bonded molecules in (II) adopt a slightly distorted tetrahedral environment. 相似文献
88.
Mehrdad Massoudi 《Mechanics Research Communications》2011,38(5):378-381
In this paper we modify the constitutive relation derived by Reiner (1945), to describe dilatancy in wet sand, by suggesting that the shear viscosity would depend on the shear rate and the volume fraction. We then look at the flow of a saturated densely packed bed of particles (with liquid in the pores) between two horizontal flat plates. We obtain exact solutions for a very special case. 相似文献
89.
Mehrdad Lakestani 《Journal of Computational and Applied Mathematics》2011,235(11):3291-3303
An effective method based upon Legendre multiwavelets is proposed for the solution of Fredholm weakly singular integro-differential equations. The properties of Legendre multiwavelets are first given and their operational matrices of integral are constructed. These wavelets are utilized to reduce the solution of the given integro-differential equation to the solution of a sparse linear system of algebraic equations. In order to save memory requirement and computational time, a threshold procedure is applied to obtain the solution to this system of algebraic equations. Through numerical examples, performance of the present method is investigated concerning the convergence and the sparseness of the resulted matrix equation. 相似文献
90.
Abbas Mehrdad Mohammad Taghi Taghizadeh Roghieh Moladoust 《Journal of solution chemistry》2011,40(5):832-842
In this work, the intrinsic viscosities of poly(ethylene glycol) with a molar mass of 20 kg⋅mol−1 were measured in water/1-propanol solutions from 283.1 to 313.1 K. The expansion factors of the polymer chains were calculated
from the intrinsic viscosity data. The thermodynamic parameters entropy of dilution parameter, the heat of dilution parameter,
theta temperature, polymer–solvent interaction parameter and second osmotic virial coefficient were derived from the temperature
dependence of the polymer chain expansion factor. The thermodynamic parameters indicate that mixtures of water/1-propanol
become weaker solvents for poly(ethylene glycol) with increasing temperature. Also, the thermodynamic parameters indicate
that the solvent ability of mixed water/1-propanol for poly(ethylene glycol) is less than that of pure water. 相似文献