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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Inorganic Chemistry Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Schiff base Complexes,Bimetallic complexes,Mercury complexes
- چکیده:
- چکیده انگلیسی: New hetero-binuclear Hg-Cu Schiff base complexes were prepared by reaction of 2,2'-[1,1'-(2,2-dimethylpropane-1,3-diyldinitrilo)-diethyldyne]diphenolato}copper(II) (CuL1) and 6,6'-X-2,2'-[(2,2-dimethylpropane-1,3-diyl)bis(nitrilomethanylylidene)]diphenolato copper(II) [(X = ethoxy (CuL2) and methoxy (CuL3)], with HgCl2 to give [Cu(L1)HgCl2] (1), [Cu(L2)HgCl2] (2), and [Cu(L3)HgCl2] (3), respectively. In the precursor Cu(II) complexes (CuL1-CuL3), the coordinated phenolic oxygen atoms and those of the substituents at 3,3'-positions (in 2 and 3) on aromatic ring can act as additional site of coordination to HgCl2 as metallo-ligand to make heterobinuclear Cu-Hg complexes. The H2L1, H2L2, and H2L3 Schiff base ligands were characterized by elemental analyses, 1H NMR and FT IR techniques. The related binuclear Cu-Hg complexes were characterized by elemental analyses and single-crystal X-ray diffraction. The main coordination sites for the HgCl2 unit are phenolic oxygen atoms and there are also short intramolecular Hg…O (methoxy, and ethoxy segments) contacts in 2 and 3. The crystal packing of 3 shows one-dimensional extended chains along the b-axis through pair of centro-symmetric C–H…Cl interactions. The new complexes crystallize in Pbca (1), P21/n (2), and P21/c (3) space groups.
- انتشار مقاله: 23-02-1393
- نویسندگان: Hadi Kargar,Reza Kia*
- مشاهده
- جایگاه : پژوهشی
- مجله: Physical Chemistry Research
- نوع مقاله: Journal Article
- کلمات کلیدی: TiO2-based photocatalysts,Anatase and rutile,Oxygen deficiency,Full-potential density functional theory
- چکیده:
- چکیده انگلیسی: In this study, a full-potential density functional theory was used to investigate the effects of Ti substitution by different cations. In both rutile and anatase, Ti atom was replaced by Ce, Au, Sn, Ag, Mo, Nb, Zr, and Y. Phase stability, electronic structure and formation energy of oxygen vacancy were compared for rutile and anatase. The results indicated that substitution of Ce and Zr increases anatase stability through which photocatalytic activity is enhanced. It seems that the cationic capacity and size play a critical role in anatase to rutile phase transition, where with an equi- or higher valence than Ti, larger cations increase the stability of anatase phase. Oxygen vacancy concentration, as a second factor of photocatalytic activity, was also studied by calculating its stability due to the cationic substitution. The data revealed that Au, Ag, Y, Ce and Sn effectively reduce oxygen-vacancy formation energy. Of the studied cations, Au and Ag had maximum reduction in band gap, by creating defect states in the middle of the band gap resulting from the overlaps of these elements d-orbitals and oxygen p-orbitals. Mo and Ce impurities did not have a significant effect on reducing gaps by creating defect states under the conduction band. Finally, Sn impurity also generated defect states in the middle of the gap merely with the lack of oxygen.
- انتشار مقاله: 06-02-1397
- نویسندگان: Seyed Mahmoud Esfandfard,Mohammad Reza Elahifard,Reza Behjatmanesh-Ardakani,Hadi Kargar
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Computational and Applied Research in Mechanical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Optimization algorithm,Parametric geometry,loss coefficient,multi-point objective function
- چکیده:
- چکیده انگلیسی: Improving the efficiency of compressors has been one of the most important goals of researchers over the years. In this paper, three different methods are presented for parameterization and blade optimization of axial flow compressor. All methods consist of flow analysis tool, optimization algorithms, and parametric geometry generation tool, that are different in each approach. Objective function is defined based on the aerodynamic performance of blade in the acceptable incidence angles range. A DCA blade is used as the initial guess for all methods. The performance of optimized blades and the initial blade are compared for evaluating the capability of various methods that a good agreement has been achieved. The results show that the value of performance improvement in each method depends on the number and type of the chosen parameters. All three methods have improved blade performance at the design incidence angle. However, only the first method shows significant performance improvement in off-design conditions.
- انتشار مقاله: 09-07-1395
- نویسندگان: Omid Fathi,Hadi Kargarsharifabad
- مشاهده
- جایگاه : پژوهشی
- مجله: Biquarterly Iranian Journal of Analytical Chemistry
- نوع مقاله: Journal Article
- کلمات کلیدی: Response surface methodology,Ionophore,Central composite design,Ion-Selective Electrode,Polyvinyl Chloride Membrane
- چکیده: در این کار روش سطح پاسخ همراه با روش طرح ترکیب مرکزی برای شبیهسازی و بهینهسازی اثر برخی متغیرها (مقادیر پلیوینیلکلرید، یونوفر، افزودنی و نرمکننده) بر عملکرد الکترود یونگزین سرب استفاده شده است. شیب 1/29 میلیولت در مقادیر بهینه از پلیوینیلکلرید (0283/0 گرم)، یونوفر(0074/0 گرم)، افزودنی (002/0 گرم) و نرم کننده (060/0 گرم) به دست آمد. محدوده خطی غلظت 1-10×0/1-5-10×0/1 مولار با روش پتانسیومتری برای سرب بدست آمد. تکنیک اسپکتروسکوپی امپدانس الکتروشیمیایی برای ارزیابی مکانیسم پاسخ الکترود بکار برده شد. نتایج بدست آمده از اسپکتروسکوپی امپدانس الکتروشیمیایی محدوده خطی غلظتی از 6-10× 0/1 تا 1-10×0/1 مولار را نشان میدهد. همچنین در مقایسه با روش پتانسیومتری محدوده pH بدست آمده از 3 تا 5/5 به مقدار 5/2 تا 0/6 افزایش پیدا کرد.
- چکیده انگلیسی: In this work, response surface methodology in conjunction with central composite design for modeling and optimization of the influence of some process variables (polyvinyl chloride (F1), ionophore (F2), additive (F3) and plasticizer (F4) amounts), on the performance of polyvinyl chloride membrane lead (ІІ) ion-selective electrode is discussed. The slope of 29.1 ± 0.1 mV at the optimal amounts of polyvinyl chloride (0.0283 g), ionophore (0.0074 g), additive (0.002 g) and plasticizer (0.060 g) has been achieved. The electrode exhibited a linear potential response to lead (II) in the concentration range of 1.0 × 10-5 mol L-1 to 1.0 × 10-1 mol L-1 over pH range of 3.0 - 5.5. Greatly, the alternating current impedance technique was applied to investigate the response mechanism of the electrode. The results were obtained from electrochemical impedance spectroscopy shows a linear concentrations range of 1.0 × 10-6 mol L-1 to 1.0×10-1 mol L-1 and in comparison with potentiometry, the pH range increased to 2.5 − 6.0.
- انتشار مقاله: 19-07-1395
- نویسندگان: Mohammad Mazloum-Ardakani,Azimeh Mandegari,Alireza Khoshroo Khoshroo,Saeed Masoum,Hadi Kargar
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Nano Dimension
- نوع مقاله: Journal Article
- کلمات کلیدی: Ethylene glycol,Thermal conductivity,Copper Oxide Nanoparticle,Hybrid Nanofluids,Single-Wall Carbon Nanotube
- چکیده:
- چکیده انگلیسی: The purpose of this study is to use the thermal and electrical conductivities of copper oxide nanoparticles and carbon nanotubes for the preparation of high-performance nanofluids for achieving better heat transfer properties. These nanofluids consist of a water/Ethylene Glycol solution containing single-wall carbon nanotubes (SWCNTs) and copper oxide nanoparticles (CuONPs). The effects of such independent variables as CuONPs and SWCNT concentrations, Ethylene Glycol ratio and solution pH were optimized to enhance the Thermal conductivity by the response surface method. The experimental results revealed that adding small amounts of nanoparticles to water/Ethylene Glycol mixtures would improve the thermal and electrical conductivity of nanofluids. The morphology of the nanoparticles was investigated by Scanning and Transmission Electron Microscopy (SEM and TEM) and Energy-Dispersive X-ray Spectroscopy (EDS). For the first time, the electrical conductivity of nanofluids was investigated by electrical impedance spectroscopy. The combined effects of both nanoparticles and nanotubes on thermal and electrical properties of the base fluid were compared to the influence of each on the same base fluid. The electrical and thermal conductivities could be enhanced by 18000 % and 157 % by addition of 0.41 % wt of SWCNT and 1.15 % wt of CuONPs to a 44:56 Ethylene Glycol-water mixture.
- انتشار مقاله: 14-02-1399
- نویسندگان: Amir Asadikia,Seyed Ali Agha Mirjalily,Navid Nasirizadeh,Hadi Kargarsharifabad
- مشاهده
- جایگاه : پژوهشی
- مجله: Inorganic Chemistry Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Schiff base Complexes,Bimetallic complexes,Mercury complexes
- چکیده:
- چکیده انگلیسی: New hetero-binuclear Hg-Cu Schiff base complexes were prepared by reaction of 2,2'-[1,1'-(2,2-dimethylpropane-1,3-diyldinitrilo)-diethyldyne]diphenolato}copper(II) (CuL1) and 6,6'-X-2,2'-[(2,2-dimethylpropane-1,3-diyl)bis(nitrilomethanylylidene)]diphenolato copper(II) [(X = ethoxy (CuL2) and methoxy (CuL3)], with HgCl2 to give [Cu(L1)HgCl2] (1), [Cu(L2)HgCl2] (2), and [Cu(L3)HgCl2] (3), respectively. In the precursor Cu(II) complexes (CuL1-CuL3), the coordinated phenolic oxygen atoms and those of the substituents at 3,3'-positions (in 2 and 3) on aromatic ring can act as additional site of coordination to HgCl2 as metallo-ligand to make heterobinuclear Cu-Hg complexes. The H2L1, H2L2, and H2L3 Schiff base ligands were characterized by elemental analyses, 1H NMR and FT IR techniques. The related binuclear Cu-Hg complexes were characterized by elemental analyses and single-crystal X-ray diffraction. The main coordination sites for the HgCl2 unit are phenolic oxygen atoms and there are also short intramolecular Hg…O (methoxy, and ethoxy segments) contacts in 2 and 3. The crystal packing of 3 shows one-dimensional extended chains along the b-axis through pair of centro-symmetric C–H…Cl interactions. The new complexes crystallize in Pbca (1), P21/n (2), and P21/c (3) space groups.
- انتشار مقاله: 23-02-1393
- نویسندگان: Hadi Kargar,Reza Kia*
- مشاهده