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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Nanoanalysis
- نوع مقاله: Journal Article
- کلمات کلیدی: crystal structure,Hydrothermal,Rietveld,Biginelli,Sr2Nb2O7
- چکیده:
- چکیده انگلیسی: Nano powders Eu3+ and Nd3+ - doped Sr2Nb2O7 were prepared by a low temperature hydrothermal
method at 120 ºC for 48 h followed by annealing at 400 ᵒC for 3 h among Sr(NO3)2
and Nb2O5, Eu2O3 and Nd2O3 raw materials at stoichiometric 1:1 Sr:Nb molar ratio. Characterization
of the synthesized materials was performed by X-ray powder diffraction (XRPD)
technique. FullProf program employing profile matching with constant scale factors was employed
for structural analysis. The results showed that the patterns had a main Sr2Nb2O7 orthorhombic
crystal structure with space group . FESEM images showed that the synthesized
nanomaterials had flower morphologies. Ultraviolet-visible spectra analysis showed that the
synthesized Eu3+ and Nd3+ - doped Sr2Nb2O7 nanomaterials had light absorption in the ultraviolet
light region. The direct optical band gap energies obtained from UV-Vis absorption spectra
were 3.45, 3.50 and 3.80 eV for pure Sr2Nb2O7, S2 and S4, respectively. The catalytic activity of
the obtained materials in the one-pot synthesis of the heterocyclic compounds 3,4-dihydropyrimidin-
2(1H)-ones (DHPMs) in Biginelli reaction is investigated. The optimized 0.03 g of the
catalyst, 95 ºC reaction temperature, and 60 min reaction time are used for the other Biginelli
reactions in this work.- انتشار مقاله: 31-04-1396
- نویسندگان: Shahin Khademinia,Mahdi Behzad
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Immunology
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: Background: Studies have indicated that extraweight and obesity induce chronic inflammation, which can lead to other diseases such as cancers. Objective: To evaluate the effects of two weight-lowering and anti-inflammatory agents including cinnamon, and turmeric, on serum levels of interleukin-17 (IL-17) as a pro-inflammatory cytokine. Methods: In this study, 64 rats were designated in eight groups. The control group received normal diet. The other groups were fed with normal diet plus high cinnamon (3 mg/ml), high turmeric (3 mg/ml), high-fructose solution (30%), fructose solution with low (0.15 mg/ml) and high doses (3 mg/ml) of cinnamon and turmeric three times per week. The serum level of IL-17F was measured by enzyme-linked immunosorbent assay (ELISA). Results: High fructose consumption led to an increase in the weight and serum level of IL-17. While, feeding with cinnamon and turmeric caused to decline weight but, surprisingly increased IL-17F levels. Conclusion: Although, some studies have showed that cinnamon and turmeric supplementation decreased IL-17F under the standard diet, in the presence of high fructose diet and extraweight their effects were reversed and caused an increase in serum level of IL-17F.
- انتشار مقاله: 26-12-1396
- نویسندگان: Maryam Sohrabi,Mahdi Alahgholi-Hajibehzad,Zahra Gholami Mahmoodian,Sayed Ali Hosseini Siyar,Alireza Zamani
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Nano Dimension
- نوع مقاله: Journal Article
- کلمات کلیدی: electrochemical impedance spectroscopy,Magnetic property,Combustion synthesis,Nano-structure characterization,X-ray powder diffraction
- چکیده:
- چکیده انگلیسی: Pure (S1) and Dy3+-doped α-Fe2O3 (S2 and S3) nanoparticles were prepared by a combustion synthesis method at 700 ºC for 8 h using Fe(acac)3 (Tris(acetylacetonato)Iron(III)) as raw material. Characterizations of the prepared powders were carried out by powder X-ray diffraction (PXRD). Structural analysis was performed by the FullProf program employing profile matching with constant scale factors. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), electrochemical impedance spectroscopy (EIS), elemental maps analysis and energy-dispersive X-ray spectroscopy (EDS) were also performed to determine the dopant amount in the α-Fe2O3 crystal structure (S3). The results showed that the patterns had a main hexagonal structure with space group R . The cell parameters data, calculated by rietveld analysis, showed that the cell parameters were decreased with increasing the dopant (Dy3+) amount in the α-Fe2O3 crystal structure. The average particles sizes estimated from TEM images for S3 were about 60 nm. Besides, the magnetic properties of S1 and S3 were measured by vibrating sample magnetometer (VSM). It was found that with the addition of Dy3+ ions into the Fe2O3 system, the coercivity was decreased and the remanent magnetization was abruptly increased. The influence of dysprosium addition was also studied using electrochemical impedance spectroscopy. This study showed that in the presence of dysprosium ion, the charge transfer resistant increased in the electrochemical process.
- انتشار مقاله: 05-06-1396
- نویسندگان: Mahbobeh Jafari,Mahdi Salehi,Mahdi Behzad
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of New Chemistry
- نوع مقاله: Journal Article
- کلمات کلیدی: Response surface methodology,Biodiesel,Transesterification,Kanemite,Solid base catalyst
- چکیده:
- چکیده انگلیسی: Kanemite was readily prepared and used as solid base catalyst for transesterification of sunflower oil to fatty acid methyl ester (FAME). The catalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption-desorption and field emission scanning electron microscopy (FESEM) techniques. Central Composite Design (CCD) coupled with Response Surface Methodology (RSM) was utilized to study the effects of the system variables such as catalyst amount, methanol to oil molar ratio, reaction time and specifically, the effect of interaction between process variables on the conversion of oil to biodiesel. Under the optimum reaction conditions (5 wt.% catalyst loading, methanol to oil molar ratio 22:1 and reaction time 240 min), the highest predicted and experimental fatty acid methyl ester conversions were 95.97% and 94.17% ,respectively. Besides, the reusability of the prepared catalyst was checked for five cycles under the optimal reaction conditions. No significant loss of the product yield was observed.
- انتشار مقاله: 19-08-1398
- نویسندگان: Abolfazl Ghaffari,Mahdi Behzad
- مشاهده