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Showing 2 results for Afzali
Hazard identification and risk assessment of high voltage power lines in residential areas using failure modes and effects analysis (FMEA)
Sa Jozi, N Jafarzadeh Haghighi Fard, N Afzali Behbahani,
Volume 7, Issue 1 (7-2014)
Abstract

Background: FMEA is one of the best known system safety techniques widely used as an identification tool. The purpose of this study was to apply FMEA method to identify and assess the risks posed by power lines in a residential area is Hasyrabad, Ahwaz. Materials and Methods: First, we identified the power line process and the equipment involved. Later, we determined the failure modes of equipment, which leads to the risk in the area studied. In order to measure the magnetic field lines, we used 3D EMF TESTER. Risks identified were scored based on the FMEA and for each case we calculated RPN. Then, with the help of SPSS software, we calculated level of risk and the cases identified were prioritized and analyzed based on the risk level. Results: The highest RPN values were associated with health risks and all risks involved in this group are at emergency conditions. It was revealed that wires (loss of privacy) and power transmission line (non-compliance with privacy standards) had highest value (RPN 360) and disconnect switch had lowest value (RPN 60). Conclusion: Due to the high risk in most cases, control measures were proposed based on the expertise in the safety-related equipment, training operators, and regulatory measures in order to reduce the level of risk.


Adsorption of silica from aqueous solution onto magnesium oxide nanoparticle: kinetic and equilibrium studies
Nahied Shahbodaghi, Daryoush Afzali, Maryam Fayazi,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: With increasing water pollution, serious water shortages and increased pressure to save water, recycling and reuse of water has attracted more attention in various industries. Removal of silica from cooling water is essential for recycling and reuse of water. The aim of this study was to remove silica from water using magnesium oxide nanoparticles (MgO) synthesized by chemical deposition method.
Materials and Methods: Synthetic nanoparticles were successfully determined using field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). To determine the optimal adsorption conditions the batch system, the effect of important parameters such as pH (2-8), contact time (0-150 min), initial concentration of silica solution (50-1000 mg/L), adsorbent amount (0.01-0.14 g) and temperature (25-60 ˚C) were studied.
Results: Under optimal conditions, an almost removal of 200 mg/L silica solution was achieved in 60 min reaction time. Equilibrium data were analyzed using the Langmuir and Freundlich isotherms. The adsorption process can be well described by the Langmuir model, and the maximum adsorption capacity was calculated as 75.76 mg/g. Synthetic data were analyzed using pseudo-first-order and pseudo-second-order equations. The pseudo-second-order model showed good agreement with the obtained data (R2 = 0.9949).
Conclusion: Due to the high potential of magnesium oxide nanoparticles in silica removal, it can be a good candidate for the removal of silica and industrial wastewater treatment.
 

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