فهرست مطالب

Journal of Particle Science and Technology
Volume:4 Issue: 1, Winter 2018

  • تاریخ انتشار: 1398/09/02
  • تعداد عناوین: 6
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  • Parya Tayeb Oskoie, Yagoub Mansoori* Pages 1-12
    In this work preparation of sulfonic acid functionalized magnetite encapsulated zirconia (Fe3O4@ZrO2-SO3H) has been reported. Structural, chemical, and magnetic properties of the magnetically supported catalyst have also been investigated by Fourier transform infrared (FT-IR) spectroscopy, wide angle X-ray diffraction spectroscopy (WXRD), thermal gravimetric analysis (TGA), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), Hammett acidity function and pH analysis as well as Brunauer-Emmett-Teller surface area measurement (SBET). The esterification reaction of various mono- and dicarboxylic acids with different alcohols was chosen to show the nano-catalytic activity. The reaction conditions were optimized and catalyst recovery was also demonstrated. The magnetic catalyst was magnetically separated and reused several times without significant loss of activity
    Keywords: Fe3O4@ZrO2, supported sulfonic acid, Magnetic acid catalyst, heterogeneous catalyst, Esterification
  • Nariman Nekokar, Mehdi Pourabdoli*, Ahmad Ghaderi Hamidi Pages 13-22
    Effects of Fe2O3 addition (2-20 wt%) with 1 h mechanical activation on redox reactions of Co3O4 were studied by TG/DSC, SEM, and XRD analyses. The results showed that a Fe2O3 addition from 2 to 15 wt% increases the oxygen release from 1.4 to 3.4 wt% and decreases the reduction onset temperature from 1030 to 960 °C, while it increases the oxygen uptake value and re-oxidation onset temperature respectively from 1.5 to 3.3 wt% and from 930 to 1010 °C. The increase in iron oxide to 20 wt% resulted in loss of heat storage properties due to significant reduction in oxygen release and uptake. Moreover, TG/DSC analyses revealed that reduction enthalpy of as-received Co3O4, 1 h ball milled Co3O4, and 1 h ball milled Co3O4-15% Fe2O3 are 622, 496, and 895 kJ/kg, respectively. Phase identification and TG experiments under argon atmosphere demonstrated that Fe2O3 participates in the reduction process. Furthermore, adding 15 wt% of iron oxide to cobalt oxide and 1 h mechanical activation improved the redox cyclability of cobalt oxide
    Keywords: Thermochemical, Heat storage, Cobalt oxide, Sintering, Redox cyclability
  • Segun Michael Abegunde*, Robert Oluwaseyi Ogede, Babajide Oluwagbenga Fatile, Ebenezer Tayo Aliu Pages 23-28
    With the current emergence of green chemistry to keep the environment safe, attention is being shifted towards using plant extracts as corrosion inhibitors. The inhibitive performances of Talinum triangulare leaf extract and Musa sapientum peel extract on the ZA-27 in 1.0 M and 1.5 M hydrochloric acid solutions were studied for 18 days using mass loss measurement. The corrosion inhibition efficiencies of the extracts were evaluated. The results showed promising anticorrosive performance in 1.0 M HCl. The average inhibition efficiencies recorded for Talinum triangulare leaf extract and Musa sapientum peel extract in 1.0 M HCl using 1 w/v of each extract after 18 days were evaluated as 62.30% and 63.27%, respectively, while in 1.5 M HCl; 40.54% and 38.45% were recorded for Talinum triangulare leaf extract and Musa sapientum peel as inhibitors, respectively, in 1.5 M HCl
    Keywords: Corrosion, Inhibitor, Talinum triangulare, Musa sapientum, Efficiency
  • Mehri Hejri, Mohammad Hojjat*, Seyed Gholamreza Etemad Pages 29-38
    Nanofluids are stable suspensions of nanoparticles in conventional heat transfer fluids (base fluids) that exhibit better thermal characteristics compared to those of the base fluids. It is important to clarify various aspects of nanofluids behavior. In order to identify the thermal and hydrodynamic behavior of nanofluids flowing through non-circular ducts, in the present study the laminar flow forced convective heat transfer of Al2O3/water nanofluid thorough channels with isosceles triangle cross section with constant wall heat flux was studied numerically. The effects of nanoparticle concentration, nanofluid flow rate and geometry of channels on the thermal and hydrodynamic behavior of nanofluids were studied. The single-phase model was used in simulations under steady state conditions. Results reveal that the local and average heat transfer coefficients of nanofluids are greater than those of the base fluid. Heat transfer coefficient enhancement of nanofluids increases with increase in nanoparticle concentration and Reynolds number. The local heat transfer coefficient of the base fluid and that of the nanofluids decrease with the axial distance from the channel inlet. Results also indicate that an increase in the apex angle of the channel, decreases the Nusselt number and heat transfer coefficient. The wall friction coefficient decreases with increasing axial distance from the channel inlet and approaches a constant value in the developed region. Friction coefficient and pressure drop decrease by increasing the apex angle of the channels
    Keywords: Nanofluids, heat transfer coefficient, Nusselt Number, Numerical simulation, Triangular duct
  • Monireh Heshami, Rahman Ahmadi*, Esmaeil Rahimi Pages 39-47
    In this study, the effect of microwave radiation on grindability and grinding kinetics were investigated. Microwave treatment was performed using an oven with 1100 W power and 2.45 GHz frequency. In order to study the breakage mechanism the grindability from the standard Bond ball mill work index (BBMWI) test was used with the selection function and breakage function as grinding parameters for treated and untreated samples. Based on the results of grindability, the work index (Wi) of a standard Bond ball mill after 4 min of microwave radiation decreased from 12.46 kWh/t to 6.45 kWh/t. selection function results showed that the specific rate of breakage (Si) value for the size fraction -3350� µm increased to 8.42% after microwave treatment. Cumulative breakage function results showed that microwave-treated products were coarser in comparison with untreated products. This phenomenon is more significant in coarse fractions, where the effect of microwave treatment is more obvious
    Keywords: Microwave treatment, Work index, Grindability, Specific rate of breakage, Siliceous manganese ore
  • Mona Masoudinia, Azar Bagheri Ghomi * Pages 49-57
    In this study, CdO nanoparticles (CdO NPs) were prepared with a template. The nanoparticles were characterized by XRD, scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and energy dispersive X-ray spectroscopy (EDX). The XRD pattern revealed that the final product has a cubic phase and its particle size diameter is 36.4 nm. The morphology of CdO is nanospherical. The catalytic activity of a CdO nanoparticle in the acetylation of benzyl alcohols was studied. The formation of products proceeds on the catalysts with predominantly strong base sites. The degradation of sulfathiazole antibiotic in the presence of CdO NPs was also investigated under ultraviolet irradiation. Various experimental parameters, such as initial sulfathiazole concentrations, initial CdO concentration and initial pH, were investigated. According to the results, this method has the potential to perform well in the removal of sulfathiazole.
    Keywords: Nanospherical, CdO, Nanoparticel, Acetylation, Sulfathiazole, Degradation