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Green bio-synthesis of Ni/montmorillonite nanocomposite using extract of Allium jesdianum as the nano-catalyst for electrocatalytic oxidation of methanol

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Chinese Journal of Chemical Engineering 2020年第10期28卷 2555-2565页

作者： mohammad hossein Sheikh-Mohseni Sajjad Sedaghat Pirouz Derakhshi Aliakbar Safekordi Department of Chemistry Science and Research BranchIslamic Azad UniversityTehranIran Department of Chemistry Shahr-e-Qods BranchIslamic Azad UniversityShahr-e-QodsIran Department of Chemistry North Tehran BranchIslamic Azad UniversityTehranIran

In this work,synthesis of Ni nanoparticles was carried out successfully by water extract of Allium jesdianum as a biochemical reducing agent in the presence of montmorillonite clay(MMT)as a natural solid support for the first *** the electrochemical activity of the synthesized nanocomposite was investigated in methanol electrocatalytic *** with high cation exchange capacity and nano layer structure was exposed to ion exchange conditions in nickel *** Ni^2+ion exchanged form was used in this process as a source of ions and also capping *** extract of Allium jesdianum used as a reducing agent due to abundant availability of phenolic and flavonoid *** synthesized Ni/MMT nanocomposite was characterized using UV–Vis spectroscopy(UV–Vis),Fourier Transform Infrared Spectroscopy(FT-IR),X-ray diffraction(XRD),Scanning Electron Microscopy(SEM),Transmission electron microscopy(TEM)and Energy-dispersive X-ray spectroscopy(EDX).The surface of prepared modified electrode has been characterized using SEM to evaluate the morphology,showing uniform dispersion of Ni nanoparticles with mean diameter of 12 to 20 *** modified carbon paste electrode was then used in methanol electrocatalytic oxidation *** oxidation on the proposed modified electrode surface occurs at 0.6 V and 0.3 V in alkaline and acidic medium ***,the results showed the better performance of modified electrode toward methanol electrocatalytic oxidation in comparison with carbon paste electrode that is modified by ion exchanged *** transfer coefficients and apparent charge transfer rate constant for the modified electrode in the absence of methanol in alkaline medium were respectively found as:αa=0.53,αc=0.37 and ks=1.6×10^-1 s^-***,the average value of catalytic rate constant for the electrocatalytic oxidation of methanol by the prepared nano-catalyst was estimated to be about 0.9 L·mol^-1·s^-1 by chronoamperometry *** prepare

关键词： Green biosynthesis Nanoparticles Montmorillonite Biocatalysis Methanol electrocatalytic oxidation Fuel cell

Mg-P/c-SWCNT Bone Cement: The Effect of Filler on Setting Behavior,Compressive Strength and Biocompatibility

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Journal of Bionic Engineering 2020年第1期17卷 100-112页

作者： mohammad hossein Esnaashary Alireza Khavandi Hamid Reza Rezaie Jafar Javadpour School of Metallurgical and Materials Engineering Iran University of Science and TechnologyNarmakTehran 16844Iran

Improving the strength of bone cement is one of the critical goals in cement designing to maintain their integrity and stabilize connection between the cement and their surrounding tissue during the time that the cement has been replaced by matured bone *** this aim,the authors decided to evaluate setting behavior and compressive strength of Magnesium Phosphate Cement(MPC)by adding carboxylated Single-Walled Carbon Nanotubes(c-SWCNTs)and assess the biocompatibility of the composite *** containing 0 wt%to 0.5 wt% of c-SWCNTs at the Powder to Liquid Ratio(PLR)of 1 g·mL^-1 to 2 g·mL^-1 were *** c-SWCNTs to MPC postponed the setting time of the cement at the beginning of the cementation process and preserved the reaction with a high rate for a longer *** addition,the compressive strength of MPC was enhanced to 28 MPa by adding 0.2 wt%c-SWCNTs because of producing cement with compact and uniform *** addition,cell behavior on MPC with/without c-SWCNTs indicated no cytotoxic effect alongside a suitable adhesion and proliferation of them.

关键词： magnesium phosphate cement carbon nanotube compressive strength MTT bone cement biocompatibility

Computational analysis of neutronic effects of ThO_2 rods loaded in CANDU 6 fuel assemblies

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Nuclear Science and Techniques 2016年第4期27卷 14-20页

作者： Seyed mohammad Mirvakili Zohreh Gholamzadeh Seyed Amir hossein Feghhi Reactor Research School Nuclear Science and Technology Research Institute Department of Radiation Application Shahid Beheshti UniversityG.C

Thorium as a suitable fertile with higher natural resources in comparison with uranium resources has been remarkably considered by different nuclear energy user countries in the last decades. Its prominent features such as suitable possibility for power flattening of a nuclear reactor, applicable breeder blanket to produce^(233)U fissile as well as neutron leakage prevention from a nuclear core has caused its application as power flatter, breeder material or other aimed utilizations be evaluated by the researches. In the present study, neutronics of a modeled CANDU 6loaded with Th O_2 and UO_2fuel rods have been computationally studied. The study aimed at reprocessing of burned Th O_2 seeds at CANDU 6 reactor to recover the total produced uranium, which is to be going under another compound fuel cycle. The obtained results showed all the core reactivity coefficients are sufficiently negative. The modeled core 949 GWd burn-up concluding in 99.99 %depletion of^(235)U initial loads. 18.38 kg of^(233) U was produced in the burnt Th O_2 fuel after 1-year burn-up time. In addition, 31.84 kg of^(239) Pu was produced in the UO_2 spent fuel rods after the burn-up time. After a proposed cooling time, about 50.01 kg of^(233)U will be available in the spent Th O_2 fuel.

关键词： CANDU堆中子泄漏燃料组件稳定杆计算核反应堆燃烧时间自然资源

A Wide-Neighborhood Predictor-Corrector Interior-Point Algorithm for Linear Complementarity Problems

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Journal of the Operations Research Society of China 2018年第4期6卷 529-543页

作者： mohammad Pirhaji hossein Mansouri Maryam Zangiabadi Department of Applied Mathematics Faculty of Mathematical SciencesShahrekord UniversityShahrekordIran

In this paper,a wide-neighborhood predictor-corrector feasible interiorpoint algorithm for linear complementarity problems is *** algorithm is based on using the classical affine scaling direction as a part in a corrector step,not in a predictor *** convergence analysis of the algorithm is shown,and it is proved that the algorithm has the polynomial complexity O(√n logε^(−1))which coincides with the best known iteration bound for this class of mathematical *** numerical results indicate the efficiency of the algorithm.

关键词： Linear complementarity problems Predictor-corrector algorithm Polynomial complexity

Homogeneous and nanomolar detection of hydrazine by indigocarmine as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode

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Chinese Chemical Letters 2012年第2期23卷 213-216页

作者： mohammad Mazloum-Ardakani hossein Rajabi Hadi Beitollahi Department of Chemistry Faculty of ScienceYazd UniversityYazd 89195-741Iran Department of Chemistry Faculty of ScienceYazd UniversityYazd 89195-741Iran Environment Department Research Institute of Environmental SciencesInternational Center for ScienceHigh Technology & Environmental SciencesKermanIran

The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan *** voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry *** detection limit（3σ） was determined as 27.3 nmol/*** evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.

关键词： Hydrazine Indigocarmine TiO_2 nanoparticles Modified electrode Carbon paste electrode Nanomolar detection

Complexation of Sm^(3+) and pamidronate: A DFT study

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Journal of Rare Earths 2015年第3期33卷 310-319页

作者： Masoud Arabieh mohammad Hassan Khodabandeh mohammad hossein Karimi-Jafari Carlos Platas-Iglesias Karim Zare Computational Chemistry Laboratory NSTRI 11365-8486 Tehran Iran Department of Chemistry Faculty of Science Shahid Beheshti University G.C. Evin 19839-63113 Tehran Iran Department of Bioinformatics Institute of Biochemistry and Biophysics University of Tehran 13145-1384 Tehran Iran Departamento de Química Fundamental Universidade da Coru?a Campus da Zapateira-Rúa da Fraga 10 15008 A Coru?a Spain

We reported a quantum mechanical study of the complexes formed between Sm3＋ and the bisphosphonate ligand pamidronate in aqueous solution. According to available experimental p K a values pamidronate was expected to exist in aqueous solution, at physiologically relevant p H, in its di- and tri-protonated forms（denoted by H3 L and H2L）. The most stable structures of the ligands and Sm3＋ complexes were found by using a detailed analysis of the conformational space with semiempirical and DFT methods. The results showed that both H2 L and H3 L bisphosphonates acted as a tridentate ligands in their complexes with Sm3＋. The addition of explicit water molecules to the coordination sphere of the metal not only gave different coordination numbers for H2 L and H3 L complexes（CN=9 and 10）, but also provided different trends in stabilization energies. The results highlighted the importance of considering not only an explicit first coordination shell, but also a second hydration shell, for an adequate description of this type of complexes in aqueous solution.

关键词： samarium radiopharmaceutical bisphosphonates solvent effects rare earths

Synthesis of novel disulfide-bridged dilactam crown ethers

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Chinese Chemical Letters 2007年第12期18卷 1439-1442页

作者： hossein Eshghi Seyed mohammad Seyedi Reza Sandarooss Department of Chemistry Ferdowsi University of MashhadMashhad 91775-1436Iran

The novel macrocyclic dilactams with redox-switched disulfide linkage were synthesized. These compounds were obtained from 2,2′-dithiodibenzoyl chloride in the macrocyclization step by fast addition method in moderat... 详细信息

关键词： Dilactam Disulfide Fast addition Macrocyclization Redox Switchable

Wet carbon-based solid acid/NaNO_3 as a mild and efficient reagent for nitration of aromatic compound under solvent free conditions

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Chinese Chemical Letters 2007年第9期18卷 1064-1066页

作者： Arash Shokrolahi Abbas Zali mohammad hossein Keshavarz Chemistry Department Malek-ashtar University of TechnologyShahin-shahrP.O.Box 83145-115Iran

Nitro aromatic compound can be obtained in high yields via nitration of aromatic compound with wet carbon-based solid acid and NaNO_3 under solvent free oxidation at room temperature.

关键词： Carbon-based solid acid Sodium nitrate Nitration Solvent free conditions

A comparative study of stress influence on fracture apertures in fragmented rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第1期11卷 38-45页

作者： hossein Agheshlui mohammad H.Sedaghat Siroos Azizmohammadi Department of Infrastructure Engineering The University of Melbourne Centre for Coal Seam Cas The University of Queensland Department of Petroleum Engineering Montanuniversitat Leoben

This study compares the calculated fracture apertures in a fragmented rock layer under different stress scenarios using two different approaches. Approach 1 is a simplified method using a two-dimensional(2 D) mapping of the fracture network and projects the far-field stresses to individual fractures, and calculates the dilation, normal and shear displacements using experimental stiffnesses available in the literature. Approach 2 employs a three-dimensional(3 D) finite element method(FEM) for the mechanical analysis of the fragmented rock layer considering the interaction with the neighbouring rock layers, frictional interfaces between the rock blocks, stress variations within the fragmented rock layer,and displacements, rotations and deformations of rock blocks. After calculating the fracture apertures using either of the approaches, the permeability of the fragmented rock layer is calculated by running flow simulations using the updated fracture apertures. The comparison between the results demonstrates an example of the inaccuracies that may exist in methods that use simplified assumptions such as2 D modelling, ignoring the block rotations and displacements, projected far-field stresses on fractures,and the stress variations within the rock layer. It is found that for the cases considered here, the permeability results based on apertures obtained from the simplified approach could be 40 times different from the results from apertures calculated using a full mechanical approach. Hence, 3 D mechanical modelling implementing realistic boundary conditions, while considering the displacements and rotations of rock blocks, is suggested for the calculation of apertures in fragmented rocks.

关键词： Fracture aperture change In situ stresses Frictional interfaces Ensemble permeability