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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Ultrafine Grained and Nanostructured Materials
- نوع مقاله: Journal Article
- کلمات کلیدی: Ball milling,MgxNi1-xO,Magnesium nickel oxide,Mechanically-induced self-sustaining reaction (MSR)
- چکیده:
- چکیده انگلیسی: Synthesis of magnesium nickel oxide phase such as MgxNi1-xO solid solutions has been studied in this research article using mechnochmical reaction between magnesium and nickel oxide. Mixtures of magnesium powder and nickel oxide (Mg+NiO) with stoichiometric compositions were milled for different times in a planetary ball mill. Reduction reaction of nickel oxide by magnesium via a mechanically induced self-sustaining reaction (MSR) was confirmed in the XRD measurements of the as-milled samples. Formation of nanostructured magnesium nickel oxide phases (such as Mg0.4Ni0.6O or MgNiO2) was observed after isothermal heating of the 30 minutes milled samples at 1000°C where nickel phase seems to disappear in XRD patterns. The traces of phases such as Mg0.4Ni0.6O or MgNiO2 were also observed in the as-milled mixtures. Therefore, the XRD results of the as-milled samples suggested that the formation of magnesium nickel oxide phases could be possible even after prolonged milling. The XRD and SEM results of both as-milled and isothermally heated samples indicated that the crystallite size and particle size of the final products reached to nanoscale after milling. Morphological and compositional evolution of the samples after heat treatment was monitored through SEM imaging and elemental analyses. The results confirmed that the composition of final product is close to Mg0.4Ni0.6O compound.
- انتشار مقاله: 27-11-1395
- نویسندگان: Nader Setoudeh,Cyrus Zamani,Mohammad Sajjadnejad
- مشاهده
- جایگاه : پژوهشی
- مجله: Advanced Journal of Chemistry-Section A
- نوع مقاله: Journal Article
- کلمات کلیدی: Geothermal Energy,Purification,Solar collectors,Solar ponds,Photovoltaics,Wind Energy
- چکیده:
- چکیده انگلیسی: Water and energy are the most important topics on the environment and sustainable energy development agenda. The social and economic health of the modern world depends on sustainable supply of both energy and water. Many areas worldwide suffering from fresh water shortage are becoming increasingly dependent on purification as a highly reliable and non-conventional source of fresh water. Therefore, purification market has greatly expanded in recent decades and expected to continue in the coming years. The integration of renewable energy resources in purification and water purification has become increasingly attractive. This is justified by the fact that areas of fresh water shortages have plenty of solar energy and these technologies can be used due to their low operating and maintenance costs. This review paper discusses the systems that can be used to harness renewable energy sources including, solar collectors, solar ponds, photovoltaics, wind energy and geothermal energy and finally a discussion and conclusion about some distinguished features of each process. Merging of these renewable energy sources with conventional sources has led to optimize the performance of purification plant, less maintenance requirement and reduction in overall cost. It was found that, to choose the best renewable energy source for a purification plant in a particular area, important determinative factors should be considered such as water salinity, area remoteness, plant size, technical infrastructure of the plant, capacity factor, energy consumption and capital cost of the equipment.
- انتشار مقاله: 27-07-1398
- نویسندگان: Mohammad Sajjadnejad,Seyed Mohammad Saleh Haghshenas,Vahid Tavakoli Targhi,Hossein Ghafarian Zahmatkesh,Mohammad Naeimi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advanced Journal of Chemistry-Section A
- نوع مقاله: Journal Article
- کلمات کلیدی: Sol-Gel,TiO2,photocatalytic properties,Dip coating,Methylene blue
- چکیده:
- چکیده انگلیسی: In this work, sol-gel process was chosen to produce a photocatalytic film to degrade methylene blue. To study the structural and morphological properties, a base sol of TTIP, I-PrOH, and DEA were created. Then, with addition of 45 g/L PEG 2000, 30 g/L TiO2, and 15 g/L PEG 2000+30 g/L TiO2, three other additional sols were produced. The results of the thermogravimetry and differntial thermal analysis indicated that a calcination temperature of 550 °C is sufficient to calcinate all four layers formed in four sols. Structural X-ray studies showed that, calcination temperature is dependent of the composition. The results of this study revealed that, substrate will have an effect on the photocatalytic behavior. It was concluded that the rough sand blasted surface because of creating more film islands that enhances photocatalytic behavior is a better substrate surface condition. Degradation of Mb showed that as a result of more TiO2 corporation in the film produced by the fourth sol, the fourth sol is superior in terms of photocatalytic behavior. Also it was found that, degradation of Mb is dependent on the initial concentration; and the higher initial concentration, the lower is the efficiency.
- انتشار مقاله: 15-07-1398
- نویسندگان: Mohammad Sajjadnejad,Hooman Karimi Abadeh
- مشاهده