فهرس المقالات Combustion method

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  1 - Magnetoresistance temperature dependence of LSMO and LBMO perovskite manganites
  Z. Jafari Razi S. A. Sebt A. Khajehnezhad
  10.1007/s40094-018-0310-3
  AbstractLa0.7Sr0.3MnO3 (LSMO) and La0.7Ba0.3MnO3 (LBMO) Polycrystalline manganite nanoparticles were prepared by combustion method using glycine fuel. The ignition process was done at 360 °C and 330 °C for LSMO and LBMO, respectively. Both of the samples have rhombohedr أکثر

  AbstractLa0.7Sr0.3MnO3 (LSMO) and La0.7Ba0.3MnO3 (LBMO) Polycrystalline manganite nanoparticles were prepared by combustion method using glycine fuel. The ignition process was done at 360 °C and 330 °C for LSMO and LBMO, respectively. Both of the samples have rhombohedral structure using XRD analysis. The reduction is observed in electrical resistivity when external magnetic field is applied during the decrease in temperature from 300 to 89 °K, which is due to the tunneling between particles. The magnetoresistance (MR) of samples was measured in this range of temperature in both the presence and absence of a magnetic field of about 10 kG. The colossal role of a kind of extrinsic MR which is 19% and 22% for LSMO and LBMO, respectively, has been investigated in this research. The metal–insulator transition temperature of 200 °K is recorded for LBMO. تفاصيل المقالة
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  2 - Morphology investigation of alumina nano-powders prepared by a sol-gel combustion method
  S. A. Khorrami R. Lotfi M. A. Baghchesara S. Moradi
  Highly sinterable alumina nano-powders have been synthesized by a sol-gel combustion method with glycine asfuel. The preparation involved the thermal decomposition of a chelating agent (fuel)-nitrate gel and theformation of amorphous precursors. The nanopowders calcined أکثر

  Highly sinterable alumina nano-powders have been synthesized by a sol-gel combustion method with glycine asfuel. The preparation involved the thermal decomposition of a chelating agent (fuel)-nitrate gel and theformation of amorphous precursors. The nanopowders calcined at 1100°C were characterized by X-ray powderdiffraction (XRD) and Scanning Electron Microscopy (SEM). It was found that the chelating agent and fuelused had a significant influence on the average grain size of a-A1203 nanopowder. The rate of combustionreaction between chelating agent (fuel) and nitrate was responsible for the growth of the grain. تفاصيل المقالة
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  3 - Optimization of fuel ratio in solution combustion method for fabrication of nickel aluminate spinel used in the esterification reaction
  Hamed Nayebzadeh Alireza Heydari Ali Ahmadpour Naser Saghatoleslami Amir-Hossein Azmoon
  10.22034/jna.2019.1866996.1139
  In this study, the solution combustion method as a simple, fast, and cost-effective method was utilized for the fabrication of spinel nickel aluminate as a stable material to use in the esterification reaction. The effect of fuel amount (urea) as an important parameter أکثر

  In this study, the solution combustion method as a simple, fast, and cost-effective method was utilized for the fabrication of spinel nickel aluminate as a stable material to use in the esterification reaction. The effect of fuel amount (urea) as an important parameter of the solution combustion method on the structure, properties, and performance of the sample was evaluated. The results of characterization analyses revealed the highest crystallinity with the desired diffusion of nickel cations in alumina lattice was obtained for the sample prepared at a fuel ratio of 1.5. Moreover, a large pore size without any agglomerated particle was observed because of releasing a huge amount of gases and high reaction temperature formed during the combustion reaction. The sulfate groups were impregnated on the NiAl2O4 surface to increase the sample activity in the esterification reaction. The chelating bidentate structure can confirm suitable bonding of sulfate groups with the surface of NiAl2O4. Evaluating the nanocatalyst activity in the esterification reaction of oleic acid confirmed the high activity of SO42-/NiAl2O4 nanocatalyst (94.2%) at the optimum condition of 120℃, 6 molar ratio of methanol/oleic acid, 3 wt.% of catalyst, and 3 h reaction time. In addition, stability assessment of nanocatalyst with and without post-treatment after each run exhibited that the porosity blocking and poisoning of the surface functional group were the major reasons for reducing the activity of the nanocatalyst. This activity was increased more than two times when the nanocatalyst was treated by washing and calcination (five cycles) after each use. تفاصيل المقالة
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  4 - Optimization of fuel ratio in solution combustion method for fabrication of nickel aluminate spinel used in the esterification reaction
  Alireza Heydari Ali Ahmadpour Hamed Nayebzadeh Naser Saghatoleslami Amir-Hossein Azmoon
  10.22034/jna.2019.668032
  In this study, the solution combustion method as a simple, fast, and cost-effective method was utilizedfor the fabrication of spinel nickel aluminate as a stable material to use in the esterification reaction.The effect of fuel amount (urea) as an important parameter of أکثر

  In this study, the solution combustion method as a simple, fast, and cost-effective method was utilizedfor the fabrication of spinel nickel aluminate as a stable material to use in the esterification reaction.The effect of fuel amount (urea) as an important parameter of the solution combustion method on thestructure, properties, and performance of the sample was evaluated. The results of characterizationanalyses revealed the highest crystallinity with the desired diffusion of nickel cations in alumina latticewas obtained for the sample prepared at a fuel ratio of 1.5. Moreover, a large pore size without anyagglomerated particle was observed because of releasing a huge amount of gases and high reactiontemperature formed during the combustion reaction. The sulfate groups were impregnated on theNiAl2O4 surface to increase the sample activity in the esterification reaction. The chelating bidentatestructure can confirm suitable bonding of sulfate groups with the surface of NiAl2O4. Evaluating thenanocatalyst activity in the esterification reaction of oleic acid confirmed the high activity of SO42-/NiAl2O4 nanocatalyst (94.2%) at the optimum condition of 120℃, 6 molar ratio of methanol/oleic acid,3 wt.% of catalyst, and 3 h reaction time. In addition, stability assessment of nanocatalyst with andwithout post-treatment after each run exhibited that the porosity blocking and poisoning of the surfacefunctional group were the major reasons for reducing the activity of the nanocatalyst. This activity wasincreased more than two times when the nanocatalyst was treated by washing and calcination (fivecycles) after each use. تفاصيل المقالة
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  5 - Synthesis of Nano-Ca doped Ceria by combustion method and investigating of effective factors on process
  Ali Ainirad
  A Synthesis of doped ceria by combustion method is performed. Two types of fuel such asurea and glycine is used to investigate the effect of fuel reactivity and reaction rate on themorphology of the resulted powders. Thermo gravimetric analysis is carried out by (TG/DTA أکثر

  A Synthesis of doped ceria by combustion method is performed. Two types of fuel such asurea and glycine is used to investigate the effect of fuel reactivity and reaction rate on themorphology of the resulted powders. Thermo gravimetric analysis is carried out by (TG/DTA,Rigaku Thermalplus TG 8120) to study the exo–endo temperature of as-received powder. Thecrystalline phases are identified by X-ray diffraction analysis (XRD). The average crystallitesize, D, is estimated by using the Scherrer formula about 40nm. The calculated lattice parameteris 5.44Å. A FT-IR study is carried out on the obtained gel and reveals that a Glycine-Metalcomplex is formed in alkaline conditions which help in preventing metal ions selectiveprecipitation and in maintaining the compositional homogeneity of the resulted powder.Finally, the effect of pH value, in the primary solution, and fuel type on the powdercharacteristics such as lattice parameter and morphologies are described. تفاصيل المقالة