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حرية الوصول المقاله
1 - Optical and structural characterization of CdSe:Eu films at different volumes of europium concentration.
Diemiruaye Jeroh Azubike Ekpunobi Donald OkoliCadmium selenide films were prepared at different volumes of dopant (Europium) concentration by electrostatic-spray-pyrolysis technique. Optical results reveal low absorption and reflection with a corresponding high transmission in the visible region. Strong blue-shift أکثرCadmium selenide films were prepared at different volumes of dopant (Europium) concentration by electrostatic-spray-pyrolysis technique. Optical results reveal low absorption and reflection with a corresponding high transmission in the visible region. Strong blue-shift is observed for the band gap energy in all cases of growth, indicating quantum confinement effect. Scanning electron studies reveal relatively smooth surface with small-sized grains on the surface. XRD confirms the crystalline nature of the films having hexagonal (wurtzite) structure with reduction in crystallinity of the film at increased volume of dopant concentration. EDX analysis confirmed the growth of CdSe:Eu film. تفاصيل المقالة -
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2 - Investigation morphological, electrical, and optical properties of Mn-doped ZnO thin film by sol–gel spin-coating method
Mehmet ÇavaşAbstractIn this study, ZnO was doped with 0.01% Mn and it is grown on p-Si by the sol–gel spin-coating method. Obtained the thin film was studied that to understand the effect of 0.01% Mn-doping ratio on the optical and electrical properties of ZnO structure. In this co أکثرAbstractIn this study, ZnO was doped with 0.01% Mn and it is grown on p-Si by the sol–gel spin-coating method. Obtained the thin film was studied that to understand the effect of 0.01% Mn-doping ratio on the optical and electrical properties of ZnO structure. In this context, first, the morphological structure of the thin film was studied with the use of atomic force microscopy (AFM). The surface structure was obtained homogeneous, and roughness and fiber size were calculated between 27.2–33.6 and 0.595–0.673 nm, respectively. Second, the optical properties were characterized via ultraviolet–visible (UV–Vis) spectrophotometry. Third, the effect of light intensity on junction properties of the photodiode was studied. The current–voltage (I–V) of the photodiode was measured under dark and at the different intensities of illumination. Obtained results showed that the current of photodiode was increased with the intensity of illumination from 6.41 × 10−7 to 5.32 × 10−4 A. These results indicate that photocurrent under illumination is higher than the dark current. After that, the other parameters of the photodiode such as barrier height and ideality factor were determined from forwarding I–V plots using the thermionic emission model that the barrier height and the ideality factor were found 0.74 eV and 5.3, respectively. On the other hand, the capacitance–voltage (C–V) was measured at the different frequencies. The C–V characteristic shown that C–V characteristic of the photodiode was changed depends on increasing frequency. In addition, the interface density (Dit) value was decreased by increasing frequency too. Similarly, the serial resistance of the photodiode was also decreased by increasing frequency. Received all these results indicated that Mn-doped ZnO thin film sensitive to light and due to this property, it can be used for different optoelectronic applications as a photodiode and photosensor. تفاصيل المقالة -
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3 - The Effect of Magnetic Nanoparticles along with Magnetic Experimental Modeling for the Desalination of the Caspian Sea Water
Kamran Lari nikoo ostovarIn this study, samples were taken of coastal waters of Kiashahr port. Magnetic desalination consisted of exposing the sample to a Magnetic field and putting the water in physical contact with magnetic nanoparticles which were synthesized with the co-precipitation method أکثرIn this study, samples were taken of coastal waters of Kiashahr port. Magnetic desalination consisted of exposing the sample to a Magnetic field and putting the water in physical contact with magnetic nanoparticles which were synthesized with the co-precipitation method. X-ray diffractometer, Fourier transform infrared spectroscopy and field-emission scanning electron microscopy were used for the characterization of nanoparticles. The results showed nanoparticles have a spherical shape and a diameter less than 20 nm. After modifying the surface of Fe3O4 nanoparticles with SiO2 they maintained their uniform distribution and spherical shape but their size increased by 20 nm. The salinity and electrical conductivity of the sample was measured prior to and following the magnetic treatment. Maximum decrease in the level of salt and electrical conductivity was achieved when 0.1 g of nanoparticles was put in contact with sea water for 2 hours and also when sea water at a flow of 50 ml/min was introduced to a magnetic field of 30 mT for 20 seconds. The amount of salt in the sample was reduced to 9.65 g/l using the above-mentioned method -having an initial value of 11.6 g/l. تفاصيل المقالة -
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4 - Preparation of (MWCNTs)-COOH/CeO2Hybrid as an Efficient Catalyst for Claisen-Schmidt Condensation
Tahereh Heidarzadeh Navabeh Nami Daryoush ZareyeeAcid functionalized multi-walled carbon nanotubes/CeO2 (MWCNTs)-COOH/CeO2 hybrid was fabricated by the reaction of functionalized (MWCNTs)-COOH and Ce(NO3)2.6H2O in acetic acid. Synthesis of CeO2 nanoparticles and their conjugation on the surface of (MWCNTs)-COOH have b أکثرAcid functionalized multi-walled carbon nanotubes/CeO2 (MWCNTs)-COOH/CeO2 hybrid was fabricated by the reaction of functionalized (MWCNTs)-COOH and Ce(NO3)2.6H2O in acetic acid. Synthesis of CeO2 nanoparticles and their conjugation on the surface of (MWCNTs)-COOH have been confirmed by FT-IR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Energy-dispersive X-ray spectroscopy (EDX). The modification of MWCNTs-COOH with CeO2 produced an efficient catalyst for the Claisen–Schmidt condensation, soa large variety of chalconeswere obtained in high yield using a catalytic amount of (MWCNTs)-COOH/CeO2 hybrid (5 mol%). تفاصيل المقالة -
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5 - Experimental Investigation of Mechanical Behavior of Improved Marly Soil Using Nano Calcium Carbonate
Ali Ohadian Mehdi MokhberiOne of the problematic soil types that is found in wide areas in the world is marl soils. This soil type is more sensitive to erosion and requires modifications in pavement construction processes. In this research, mixed soil-Nano-CaCo3 was considered. For this purpose, أکثرOne of the problematic soil types that is found in wide areas in the world is marl soils. This soil type is more sensitive to erosion and requires modifications in pavement construction processes. In this research, mixed soil-Nano-CaCo3 was considered. For this purpose, 0.3 to 2.7% Nano-CaCo3, by specific dry weight, was combined with marl soils in 0.3% increments. To analyse the geotechnical properties of marl soil, optimum water content for soil compaction, maximum dry density, uniaxial compressive strength, California Bearing Ratio (CBR) and the consolidation test were investigated. The results showed dry unit weight increases with increasing Nano-CaCo3 content up to 2.2%. Furthermore, the CBR of modified marl soil with 2% Nano-CaCo3 is 2.7 times greater than the initial CBR; it increased from 6 to 15.5 by adding up to 2% Nano-CaCo3. Moreover, adding Nano-CaCo3 to marl soil increased the uniaxial compressive stress. The optimum percentage of Nano-CaCo3 was 2%, which increased the compression strength about 1.4 times. Besides, with increasing Nano-CaCo3 up to 2.2%, the amount of void ratio decreases from 0.46 to 0.35. Additionally, the compression index Cc and swelling Index Cs are almost constant and equal to 0.09 and 0.03, respectively. تفاصيل المقالة -
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6 - Effects of reaction temperature and raw material type on optical properties and crystal phase growth of Solid state synthesized NiSb2O6 nanomaterials
Alireza HakimyfardNanostructured NiSb2O6 samples were synthesized via solid state reactions at the reaction temperatures of 600, 700 and 800 °C using Sb2O3, Ni(CH3COO)2.2H2O and Ni(NO3)2.6H2O as raw materials. Parameters of reaction temperature and raw materials types were investigat أکثرNanostructured NiSb2O6 samples were synthesized via solid state reactions at the reaction temperatures of 600, 700 and 800 °C using Sb2O3, Ni(CH3COO)2.2H2O and Ni(NO3)2.6H2O as raw materials. Parameters of reaction temperature and raw materials types were investigated for the crystal phase growth study. The synthesized nanomaterials were characterized by X-ray powder diffraction (XRPD) technique, fourier-transform infrared (FTIR) spectroscopy. Brunauer–Emmett–Teller (BET) and Barrett-Joyner-Halenda (BJH) methods were used to investigate the textural properties of the obtained samples. Rietveld analyses showed that the obtained materials were crystallized well in the tetragonal crystal structure with the space group of P42/mnm. The lattice parameters of the targets were about a = b = 4.64 Å and c = 9.22 Å. The data revealed that the crystal phase purity of the as-synthesized nanomaterials was increased with increasing the reaction temperature from 600 to 800 °C. Besides, the data indicated that the synthesis reactions using Ni(NO3)2.6H2O generated a better crystalline growth and purity compared to Ni(CH3COO)2.2H2O raw material in a certain reaction temperature. The morphologies of the synthesized materials were studied by field emission scanning electron microscopy (FESEM) technique. The FESEM images showed that the homogeneity of the synthesized powder was improved when Ni(NO3)2.6H2O was used as raw material. Ultraviolet-visible spectra showed that the synthesized NiSb2O6 nanomaterials had strong light absorption in the ultraviolet light region. The calculated direct optical band gaps tendency showed that the band gaps were increased with increasing the reaction temperature. تفاصيل المقالة -
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7 - Fabrication of Na-W Co-Doped Exfoliated G-C3N4 Nanoparticles for Methylene Blue Removal
Mohammad Javad Hakimi-Tehrani Seyed Ali Hassanzadeh Tabrizi Narjes Koupaei Ali Saffar Mahdi RafieiBulk g-C3N4 has very poor photocatalytic activity. Many methods have been utilized to increase the photocatalytic performance of this semiconductor. Here, a simple preparation was used to create exfoliated g-C3N4 that was co-doped with sodium and tungsten. The produced أکثرBulk g-C3N4 has very poor photocatalytic activity. Many methods have been utilized to increase the photocatalytic performance of this semiconductor. Here, a simple preparation was used to create exfoliated g-C3N4 that was co-doped with sodium and tungsten. The produced Na-W co-doped exfoliated g-C3N4 was characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis spectroscopy, and Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS). The doping samples with Na and W changed the band structure of the g-C3N4 lattice, which increased light absorption and caused a reduction in the band gap. The samples had layered morphology. After exfoliation and sodium and tungsten co-doping of the samples, the methylene blue photodegradation was greatly enhanced. The doping of the samples also had an impact on the dye adsorption capacity. The dye removal activity of the Na-W co-doped exfoliated g-C3N4 sample is higher than those of pure bulk g-C3N4 and pure exfoliated g-C3N4. The rate reaction constant (k) of the Na-W co-doped exfoliated g-C3N4 is up to 3.3 times greater than that of bulk g-C3N4. The produced photocatalyst may be utilized for the treatment of wastewater comprising methylene blue as the pollutant agent. تفاصيل المقالة -
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8 - Effect of Nano-MgO Additive on Compressive Strength of Concrete Fabricated by Different Processing Methods
Eisa Mahmoudsaleh Ali Heidari Farshid Fathi Seyed Ali HassanzadehTabriziThe effects of adding different nano-MgO dosages (0, 1, 2, 3, and 4 wt.% with respect to cement) on microstructural, compressive strength, and phase evaluation of concrete were investigated. Two different post-treatment conditions with water and CO2 gas were used to stu أکثرThe effects of adding different nano-MgO dosages (0, 1, 2, 3, and 4 wt.% with respect to cement) on microstructural, compressive strength, and phase evaluation of concrete were investigated. Two different post-treatment conditions with water and CO2 gas were used to study the processing method on the samples. The specimens were characterized via SEM and XRD analysis. The mechanical properties of the samples were also investigated. The results showed that compressive strength significantly improved after the addition of magnesium oxide nanoparticles. However, this improvement was more remarkable in the case of post-treatment with CO2 compared to the samples fabricated with water. SEM results showed that the samples treated under CO2 gas had irregular and needle-like morphology. The samples prepared by normal processing had CaCO3 and SiO2 phases, whereas the ones fabricated under CO2 gas contained CaCO3, SiO2, and Ca(OH)2. With the addition of nano-MgO, the density of concrete decreases in the samples post-treated with water, whereas it increases for the samples post-treatment with CO2 gas. Adding 4 wt.% nano-MgO to concrete and further post-treatment with CO2 for 45 days could increase the mechanical properties from ~ 23 MPa to ~ 55 MPa. تفاصيل المقالة -
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9 - Solid state synthesis, crystal structure, evaluation of direct and indirect band gap energies and optimization of reaction parameters for As2Ni3O8 nanomaterials
Alireza Hakimyfard shahin khademinia masumeh rahimkhaniNanostructured As2Ni3O8 samples were synthesized via facile solid state reactions at 850 and 950 °C for 8h using As2O3, Ni(CH3COO)2.2H2O and Ni(NO3)2.6H2O raw materials. The synthesized nanomaterials were characterized by powder X-ray diffraction (PXRD) technique and fo أکثرNanostructured As2Ni3O8 samples were synthesized via facile solid state reactions at 850 and 950 °C for 8h using As2O3, Ni(CH3COO)2.2H2O and Ni(NO3)2.6H2O raw materials. The synthesized nanomaterials were characterized by powder X-ray diffraction (PXRD) technique and fourier-transform infrared (FTIR) spectroscopy. The rietveld analyses showed that the obtained materials were crystallized well in monoclinic crystal structure with the space group P121/c1. The lattice parameters of the targets were about a = 5.76 Å, b = 9.54 Å and c = 10.18 Å with β = 92.95 °. It was found that nickel nitrate created a highly crystalline and pure As2Ni3O8 structure. However, nickel acetate created the target with lower purity and crystal phase growth; it produced the samples with smaller crystallite sizes. Reaction temperature changing showed that the parameter affected on the crystal growth of the obtained materials. The morphologies of the synthesized materials were studied by field emission scanning electron microscopy (FESEM) technique. Ultraviolet-visible spectra showed that the synthesized As2Ni3O8 nanomaterials had strong light absorption in the ultraviolet - visible light region. The direct optical band gaps were 2.6 and 2.5 eV for S1 and S3, respectively. The data showed that the band gaps were decreased by increasing the reaction temperature. This is due to the increasing the crystallite sizes of the obtained materials. تفاصيل المقالة -
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10 - AB INITIO MATERIAL MODELING STUDY ON LiO ADSORBED BY PALLADIUM-COBALT (PdCo) NANOPARTICLES
mikail aslanPdCo nanoalloy particles have been commonly used as catalytic material in some important chemical reactions, involving in fisher-tropsch reactions, and oxygen reduction reactions. In terms of understanding the role of catalysis, these smallest bimetallic nanoparticles p أکثرPdCo nanoalloy particles have been commonly used as catalytic material in some important chemical reactions, involving in fisher-tropsch reactions, and oxygen reduction reactions. In terms of understanding the role of catalysis, these smallest bimetallic nanoparticles provide the simplest prototypes of Pd-Co bimetallic catalysts for different compositions. In this study, the effect of LixO (x=1,2) on PdCo nanoalloys has been investigated comprehensively employing the density functional theory (DFT) to identify the mechanism of structural, electronic, and energetic properties of the studied species. Binding energies are calculated for stability analysis which is very important for nanoparticles. Results show that lithium oxides are generally adsorbed by cobalt sites on the Pd-Co substrate. This is important for determining active sites of the catalytic material. Furthermore, the structures have low symmetric properties. Hence, this study might provide an initial structural evaluation step for future studies related to the possible new catalytic material of Li-air batteries. تفاصيل المقالة -
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11 - Solid state synthesis, crystal structure, evaluation of direct and indirect band gap energies and optimization of reaction parameters for As2Ni3O8 nanomaterials
Alireza Hakimyfard Shahin Khademinia Masumeh RahimkhaniNanostructured As2Ni3O8 samples were synthesized via facile solid-state reactions at 850 and 950 °C for 8h using As2O3, Ni(CH3COO)2.2H2O and Ni(NO3)2.6H2O raw materials. The synthesized nanomaterials were characterized by powder X-ray diffraction (PXRD) technique an أکثرNanostructured As2Ni3O8 samples were synthesized via facile solid-state reactions at 850 and 950 °C for 8h using As2O3, Ni(CH3COO)2.2H2O and Ni(NO3)2.6H2O raw materials. The synthesized nanomaterials were characterized by powder X-ray diffraction (PXRD) technique and fourier-transform infrared (FTIR) spectroscopy. The rietveld analyses showed that the obtained materials were crystallized well in monoclinic crystal structure with the space group P121/c1. The lattice parameters of the targets were about a = 5.76 Å, b = 9.54 Å and c = 10.18 Å with β = 92.95 °. It was found that nickel nitrate created a highly crystalline and pure As2Ni3O8 structure. However, nickel acetate created the target with lower purity and crystal phase growth; it produced the samples with smaller crystallite sizes. Reaction temperature changing showed that the parameter affected on the crystal growth of the obtained materials. The morphologies of the synthesized materials were studied by field emission scanning electron microscopy (FESEM) technique. Ultraviolet-visible spectra showed that the synthesized As2Ni3O8 nanomaterials had strong light absorption in the ultraviolet-visible light region. The direct optical band gaps were 2.6 and 2.5 eV for S1 and S3, respectively. The data showed that the band gaps were decreased by increasing the reaction temperature. This is due to the increasing the crystallite sizes of the obtained materials. تفاصيل المقالة -
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12 - Ab initio (first principle) material modeling study on Lio adsorbed by palladium-cobalt (PdCo) nanoparticles
Mikail AslanPdCo subnanoalloys have been commonly used as a catalytic material in some important chemicalreactions, involving in fisher-tropsch reactions, and oxygen reduction reactions. In terms ofunderstanding the role of catalysis, these smallest bimetallic nanoparticles provide أکثرPdCo subnanoalloys have been commonly used as a catalytic material in some important chemicalreactions, involving in fisher-tropsch reactions, and oxygen reduction reactions. In terms ofunderstanding the role of catalysis, these smallest bimetallic nanoparticles provide the simplestprototypes of Pd-Co bimetallic catalysts for different compositions. In this study, the effect ofLixO (x=1,2) on PdCo nanoalloys has been investigated comprehensively employing the densityfunctional theory (DFT) to identify the mechanism of structural, electronic, and energeticproperties of the studied species. Binding energies are calculated for stability analysis, whichis very important for nanoparticles. Results show that lithium oxides are generally adsorbed bycobalt sites on the Pd-Co substrate. This is important for determining active sites of the catalyticmaterial. Furthermore, the structures have low symmetric properties. Hence, this study mightprovide an initial structural evaluation step for future studies related to the possible new catalyticmaterial of Li-air batteries. تفاصيل المقالة -
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13 - Deformation of Al Alloy during Integrated Extrusion and ECAP: A Simulation Research
Ankit Sahai Shanti S. Sharma Suren N. DwivediBulk nanomaterial have several applications in automobile, aerospace, medical and manufacturing applications. These are produced by subjecting materials to severe plastic deformation (SPD) and have widely emerged as a technique for grain refinement in Al, Cu, Ti, Mg all أکثرBulk nanomaterial have several applications in automobile, aerospace, medical and manufacturing applications. These are produced by subjecting materials to severe plastic deformation (SPD) and have widely emerged as a technique for grain refinement in Al, Cu, Ti, Mg alloys with improved mechanical properties. Equal Channel Angular Pressing (ECAP) is one such SPD technique employed to produce bulk ultra-fine grained (UFG) materials by introducing a large amount of shear strain into the materials without changing the billet shape or dimensions. FE (Finite Element) modeling of SPD processes has become an important tool for designing feasible production processes, because of its unique capability to describe the complex geometry and boundary conditions. In this proposed work, integrated SPD processes namely Extrusion + ECAP (Ex-ECAP) is proposed and the specimen is subjected to these processes in the same die set-up. The 3D finite element modeling of Al6061 was performed using metal forming software FORGE. The dies used in both the processes during the simulation of Al6061 billet include a channel angle of 900 and outer corner angle fixed at 160 with simulation performed for different plunger velocities. The simulation results depict the change in equivalent strain in the entire specimen on account of these processes. The evolution of strain at different considered cross-sections is analyzed. Also, the variation in extrusion force and energy are studied for the considered process parameters. The FE simulations greatly help in designing the dies for various experimental conditions to produce bulk nanomaterial. تفاصيل المقالة -
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14 - Synthesis of some chiral compounds using (MWCNTs)-COOH/Fe3O4-CaO magnetic nanostructures
Omekolsoom Shabani Navabeh Nami Rahimeh Hajinasiri Masoumeh HosseinzadehThe condensation of dimedone with sugars in the presence of a catalytic amount of (MWCNTs)-COOH/Fe3O4-CaO magnetic nanostructure gave some asymmetric furan derivatives in good yields. The products were identified by FT-IR, NMR spectra, and elemental analysis.The condensation of dimedone with sugars in the presence of a catalytic amount of (MWCNTs)-COOH/Fe3O4-CaO magnetic nanostructure gave some asymmetric furan derivatives in good yields. The products were identified by FT-IR, NMR spectra, and elemental analysis. تفاصيل المقالة -
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15 - Photocatalytic degradation of methyl orange using ZnO and Fe doped ZnO: A comparative study
Kalpesh Anil Isai Vinod Shankar ShrivatavaZnO and 2% Fe doped ZnO photocatalytic nanomaterials were successfully synthesized by successive ionic layer adsorption and the reaction (SILAR) method. The characterizations of these nanomaterials were carried out using XRD, SEM and EDX techniques. XRD study shows that أکثرZnO and 2% Fe doped ZnO photocatalytic nanomaterials were successfully synthesized by successive ionic layer adsorption and the reaction (SILAR) method. The characterizations of these nanomaterials were carried out using XRD, SEM and EDX techniques. XRD study shows that the samples have a hexagonal wurtzite crystalstructure, size of which is in the range 21-23 nm. SEM shows nanoflakes or nano flower-like morphology, while EDX reveals the compositional analysis. In this paper, we investigated photocatalytic degradation of an aqueous suspension of methyl orange (MO) dye as a model pollutant. Degradation of dye was monitored by the spectrophotometric method. The effects of various parameters such as pH, contact time, initial dye concentration and catalyst dose were studied. in optimized process, the maximum degradation obtained using ZnO was 88 % and that using Fe doped ZnO was 94 % at a pH value of 8. We have concluded that, compared to ZnO, the 2% Fe doped ZnO is a promising photocatalyst for degradation of MO. تفاصيل المقالة -
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16 - Inorganic-organic hybrid nanomaterial (Fe3O4@SiO2-AQ): A retrievable heterogeneous catalyst for the green synthesis of 4H-chromenes
Mohamad Ali Bodaghifard Zahra Faraki Zahra MozaffariPreparation of 4-aminiquinaldine grafted on silica-coated nano-Fe3O4 particles (Fe3O4@SiO2-AQ) as a novel retrievable heterogeneous nanocatalyst is described. This novel hybrid nanomaterial was applicated for the green synthesis of substituted 2-amino-4H-chromenes via t أکثرPreparation of 4-aminiquinaldine grafted on silica-coated nano-Fe3O4 particles (Fe3O4@SiO2-AQ) as a novel retrievable heterogeneous nanocatalyst is described. This novel hybrid nanomaterial was applicated for the green synthesis of substituted 2-amino-4H-chromenes via the one-pot condensation reaction of an aldehyde, malononitrile and α-naphthol/β-naphthol/phenol under solvent-free condition. Eco-friendly method, high yield and purity of the desired products, short reaction time along with the ease of the work-up procedure outlines the advantages of these new methodologies over the earlier ones. Surface and magnetic properties of the core/shell hybrid nanoparticles were characterized via transmission electron microscopy (TEM), scanning electron microscope (SEM), X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA/DTA), and Fourier-transform infrared spectroscopy (FT-IR) techniques. This nanocatalyst can be reused at least six times without considerable loss of its performance. تفاصيل المقالة -
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17 - Preparation, Characterization and Application of a Novel Organic-Inorganic Hybrid Magnetic Nanomaterial as a Highly Efficient Catalyst for the Synthesis of Bis-Coumarins
Marziyeh Barzegar Abdolkarim Zare Aysoda Ghobadpoor Manije DianatA novel organic-inorganic hybrid magnetic nanomaterial, namely nano-[Fe3O4@SiO2@R-NMe2][FeCl4] (nano-[FSRN][FeCl4]) was prepared, and characterized by EDX, elemental mapping, FE-SEM, FT-IR, XRD, VSM, TG and DTG analyses. Then, it was applied as a highly efficient and ma أکثرA novel organic-inorganic hybrid magnetic nanomaterial, namely nano-[Fe3O4@SiO2@R-NMe2][FeCl4] (nano-[FSRN][FeCl4]) was prepared, and characterized by EDX, elemental mapping, FE-SEM, FT-IR, XRD, VSM, TG and DTG analyses. Then, it was applied as a highly efficient and magnetically recyclable catalyst for the solvent-free synthesis of bis-coumarins from 4-hydroxycoumarin (2 eq.) and arylaldehydes (1 eq.). NMe2 is a basic group, and FeCl4− is a Lewis acid; thus, nano-[FSRN][FeCl4] can act as a dual-functional catalyst; based on this and the literature, a plausible mechanism was proposed for the reaction. تفاصيل المقالة -
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18 - Recent Progress in Visible-Light Active (VLA) TiO2 Nano-Structures for Enhanced Photocatalytic Activity (PCA) and Antibacterial Properties: A Review
Kasun Seneviratne Imalka Munaweera Sriyani Peiris Colin Peiris Nilwala KottegodaThe applications of photocatalytic nanomaterial technology received intense scientific focus with the advent of nanotechnology. Applications based on TiO2 nanoparticles have shown promise of photocatalytic efficiency among many semiconductor metal oxides. Titanium dioxi أکثرThe applications of photocatalytic nanomaterial technology received intense scientific focus with the advent of nanotechnology. Applications based on TiO2 nanoparticles have shown promise of photocatalytic efficiency among many semiconductor metal oxides. Titanium dioxide is utilized in many practical applications such as water and air purification, self-cleaning of surfaces, and energy production. The major drawback with TiO2 based photocatalysts is the wide band gap, which requires UV light to produce the electron-hole pairs. This review article focus on techniques/methods to eliminate band gap which reduces photocatalytic efficiency. Application of semiconductor photocatalytic techniques to degrade organic pollutants and their antimicrobial activity is discussed here using model systems. Synthetic and natural nanohybrids are available today and have varying characteristics as options. Recently developed natural mineral based nanohybrids is the new trend in photocatalytic applications. It appears that the removal efficiency of existed photocatalysts is higher than that of synthetic products. Natural nanohybrids carry the advantages of low costs, avoiding extensive synthesizing conditions in future photocatalytic applications. تفاصيل المقالة -
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19 - Nano-[SiO2@R-Im-SO3H][CF3COO]: an effectual catalyst for the production of bis-coumarins and N,N′-alkylidene bisamides
Jaleh Atashrooz Abdolkarim ZareA novel organic-inorganic hybrid nanomaterial namely nano-[SiO2@R-Im-SO3H][CF3COO] (NSRISC) was synthesized, and characterized using FT-IR, EDS, FE-SEM, TGA and XRD analyses. Thereafter, the solvent-free production of bis-coumarins (from aryl aldehydes and 4-hydroxycoum أکثرA novel organic-inorganic hybrid nanomaterial namely nano-[SiO2@R-Im-SO3H][CF3COO] (NSRISC) was synthesized, and characterized using FT-IR, EDS, FE-SEM, TGA and XRD analyses. Thereafter, the solvent-free production of bis-coumarins (from aryl aldehydes and 4-hydroxycoumarin) and N,N′-alkylidene bisamides (from aryl aldehydes and benzamide) was catalyzed by NSRISC. Bis-coumarins were produced in 86-97% at 100 ºC, and bisamides were obtained in 87-97% at 105 ºC. The reaction times were 15-30 min for both kinds of compounds. تفاصيل المقالة -
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20 - Synthesis and Characterization ZnO-Fe2O3 Nanocomposite with Thermal Plasma Method
Mohamad Reza Alikhani Shahrooz Saviz Amir Hossein SariIn the present paper, a novel thermal plasma method is proposed to synthesize ZnO-Fe2O3 nanocomposite, with different percentages of iron, namely 3, 5, and 7%. This method is an efficient feasibility of the Zno-Fe2O3 nanocomposite synthesis. The nanocomposites are synth أکثرIn the present paper, a novel thermal plasma method is proposed to synthesize ZnO-Fe2O3 nanocomposite, with different percentages of iron, namely 3, 5, and 7%. This method is an efficient feasibility of the Zno-Fe2O3 nanocomposite synthesis. The nanocomposites are synthesized by homemade direct current (DC) plasma torch. They are analyzed by different methods. The bandgap is determined by diffuse reflectance spectroscopy (DRS). The photocatalytic performance of Zno-Fe2O3 is evaluated. The results show that the structure of nanoparticles is spherical, which is more favored in the industry. Also, the particle size distribution is uniform. The average size of nanoparticle crystals increases with increasing iron content. Despite the formation of nanocomposites, due to the lack of support for nanoparticles, the results of photodegradation are not satisfactory. تفاصيل المقالة -
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21 - بررسی اثر ضدسایشی نانوذرات مغناطیسی آهن اکسید در روغن موتور چند درجهای در مقایسه با روغن موتور معمولی
فرشته قربانی نایینی حمیدرضا اسکندری داود ابراهیمیدر این پژوهش، عملکرد ضدسایشی روغن موتور حاوی نانوماده افزودنی نسبت به روغن موتور معمولی با استفاده از روشهای آزمایشگاهی، مورد مقایسه و ارزیابی قرارگرفت. برای این منظور نانوذرات مغناطیسی آهن اکسید (Fe3O4) بهعنوان نانوماده افزودنی به روغن موتور ایرانول ریسینگ SAE10W40 ان أکثردر این پژوهش، عملکرد ضدسایشی روغن موتور حاوی نانوماده افزودنی نسبت به روغن موتور معمولی با استفاده از روشهای آزمایشگاهی، مورد مقایسه و ارزیابی قرارگرفت. برای این منظور نانوذرات مغناطیسی آهن اکسید (Fe3O4) بهعنوان نانوماده افزودنی به روغن موتور ایرانول ریسینگ SAE10W40 انتخاب شد. در ابتدا پایداری نانوسیال به دست آمده با نانوذرات با استفاده از دستگاه اندازهگیری جذب مرئی- فرابنفش و پتانسیل زتا تأیید شد. مشخصات نانوذرات آهن اکسید با روشهای دستگاهی میکروسکوپی تونلزنی روبشی (STM)، طیفسنجی تفکیک انرژی (EDS) و طیفسنجی فروسرخ تبدیل فوریه (FTIR) بررسی شد. نانوذرات دارای قطری در گستره 8 تا 13 نانومتر بودند. همچنین، توزیع اندازه نانوذرات با استفاده از دستگاه پراکندگی نور دینامیکی مورد بررسی قرار گرفته است. عملکرد ضدسایشی نانوذرات Fe3O4 در روغن چند درجهای با آزمونهای چهار ساچمه و فالکس بررسی شد. بررسی نتایج بهدست آمده بهطور کلی بیانگر بهبود عملکرد ضدسایشی روغن موتور ناشی از افزودن نانوذرات بود. نانوذرات مغناطیسی آهن اکسید با غلظت 1/0 درصد، افرایش قدرت جوش خوردگی روغن موتور چند درجهای از 32/76 به 74/92 کیلوگرم نیرو و افزایش شاخص بار سایش از 250 به 315 کیلوگرم نیرو را در آزمون چهار ساچمه از خود نشان میدهد. افزون بر آن باعث افزایش حد تحمل بارهای خطی از 1160 به 1220 پوند نیرو در مقایسه با روغن موتور معمولی شده است. تفاصيل المقالة -
حرية الوصول المقاله
22 - کاربرد نانوذرههای استرانسیم فرریت برای اندازهگیری الکتروشیمیایی هیدرازین در سطح نانومولار
محمد علی شیخ محسنی قاسم مرندیبا توجه به اهمیت مقدار هیدرازین در نمونههای آبی متفاوت از نقطه نظرات زیستمحیطی و همچنین، کاربرد فراوان این ماده، نیاز است که غلظت آن در نمونههای متفاوت اندازهگیری شود. در این پژوهش، سعی شده است یک الکترود جدید و درعینحال ساده و ارزان برای اندازهگیری هیدرازین پیشنه أکثربا توجه به اهمیت مقدار هیدرازین در نمونههای آبی متفاوت از نقطه نظرات زیستمحیطی و همچنین، کاربرد فراوان این ماده، نیاز است که غلظت آن در نمونههای متفاوت اندازهگیری شود. در این پژوهش، سعی شده است یک الکترود جدید و درعینحال ساده و ارزان برای اندازهگیری هیدرازین پیشنهاد و ارائه شود. این الکترود، یک الکترود خمیر کربن اصلاحشده با نانوذرههای استرانسیم فرریت است. این الکترود به دلیل وجود نانوذرهها در ساختمان خود حساسیت و انتخابگری خوبی در الکتروآنالیز هیدرازین دارد. نتایج روشهای ولتاسنجی چرخهای و زمان-آمپرسنجی به خوبی اکسایش کاتالیستی هیدرازین در سطح الکترود پیشنهادی را نشان دادند. حسگر ساختهشده دارای دو گستره خطی، یکی در گستره 5/0 تا 20 میکرومولار و دیگری در گستره 20 تا 600 میکرومولار برای هیدرازین است. این الکترود گزینشپذیری مناسبی در اندازهگیری هیدرازین از خود نشان داد. بررسی تکرارپذیری، تجدیدپذیری و طول عمر الکترود نیز انجام گرفت و نتایج قابل قبولی به دست آمد. اندازهگیری هیدرازین در نمونههای آبی متفاوت مانند آب شهر و آب چاه انجام گرفت. درصدهای بازیابی محاسبهشده در نمونههای حقیقی نشان داد که توانایی الکترود ساختهشده در اندازهگیری نمونههای واقعی خوب و قابلاطمینان است. تفاصيل المقالة -
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23 - Comparative Risk Assessment of Tasks Involved with Nanomaterials Using NanoTool & Guidance Methods
Fakhradin Ahmadi Kanrash Soqrat Omari Shekaftik Amirhossein Aliakbar Fatemeh Soleimany Azad Haghighi Asl Wahab Ebrahimi Saeedeh Amini RavandiAssessing the risks related to the advancement of science and technology has always been accompanied by many uncertainties. As a new field of science, nanotechnology faces numerous uncertainties concerning safety, health, and environmental aspects dealing with which req أکثرAssessing the risks related to the advancement of science and technology has always been accompanied by many uncertainties. As a new field of science, nanotechnology faces numerous uncertainties concerning safety, health, and environmental aspects dealing with which requires a proper risk assessment. Accordingly, this study intended to assess the risk of tasks associated with nanomaterials comparatively, examining the risks in eighteen companies in Tehran. The two proposed risk-assessment methods for the activities involving nanomaterials (NanoTool and Guidance) assisted in assessing the risk of their tasks. The results were analyzed using SPSS.22 and the chi-square test and indicated the different outputs of the two methods despite being designed based on the control banding approach. These differences could be attributed to the different risk-assessment parameters that these methods considered. The statistical analysis results also showed no significant relationship between them. Given the large differences and insignificant association between risk assessment results, the guidance method was less effective than the nanotool method. However, straightforwardness and convivence of implementation in the workplace and various research environments make it a helpful method in initial evaluations. تفاصيل المقالة -
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24 - Adsorption and Removal of Pollutants (dyes) from Wastewater Using Different Types of Low-cost Adsorbents: A review
Ahmed B. Mahdi Aseel M. Aljeboree Ayad F. AlkaimDischarge of dye-containing wastewater from various industries like textile, leather, paint, cosmetics etc. industries contributes to large amounts of pollution, leading to serious environmental problems such as quality deterioration of fresh water and endangering ecosy أکثرDischarge of dye-containing wastewater from various industries like textile, leather, paint, cosmetics etc. industries contributes to large amounts of pollution, leading to serious environmental problems such as quality deterioration of fresh water and endangering ecosystems' health. One of the conventional anti-fungal agent in aquaculture which should be eliminated from wastewaters prior to releasing it into natural water resources. Tremendous volumes of colored wastewater are generated in textile, leather, paint, cosmetics etc. industries, causing eternal damage to the water resources. Wastewaters released from dye production and application industries are responsible for water pollution. Untreated disposal of the colored water into receiving water body causes damage to aquatic life and human bodies. Due to the high toxicity of dyes at low concentrations, they must be treated before being discharged into the receiving body of water. Therefore, environmental legislation has imposed severe limits on the discharged effluents' concentrations from dyestuff manufacturing and textile industries. تفاصيل المقالة
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