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Yashar Azizian-Kalandaragh 대한전자공학회 2018 Journal of semiconductor technology and science Vol.18 No.1
In this research, a simple ultrasound-assisted method has been used for the preparation of lead oxide nanostructures in the presence of polyvinyl alcohol (PVA) as a capping agent. Different concentrations of PVA were added to the mixture to control of nanostructure size. The as-prepared lead oxide nanostructures have been investigated by UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). UV-Vis spectroscopy results show a shift in the peaks and broadening with increasing of PVA amount. The XRD pattern indicates the uncapped sample contain mixture phase of lead oxides and PVA-capped samples were high purity and no other peaks were observed. The average crystallite size of nanoparticles was estimated using Debye-Scherrer's formula and the measured sizes reveal clearly the crystallite size decreases with increasing PVA concentration. The SEM results show by increasing in capping agent concentration, the distribution of nanoparticles has been changed. FT-IR Spectroscopy results show by increasing of capping agent concentration the energy between the functional group is changed and some peaks show a slight shift.
Saeid Azizian,Maryam Khoshnood 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.5
Removal of a pesticide (2,4-dichlorophenoxyacetic acid) from aqueous solution by magnetic and graphitic carbon nanostructures was studied from both equilibrium and kinetic point of view. The magnetic and graphitic carbon nanostructures as adsorbents were prepared from two different biomasses, cotton and filter paper. The resultant adsorbents were characterized with TEM and N2adsorption–desorption methods. The kinetic and equilibrium data were modeled with different models. The adsorption capacities for the prepared adsorbents from filter paper and cotton are about 77 and 33 mg/g, respectively. The effect of initial pH of solution on the pesticide removal efficiency was studied too. 2012 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Adsorption of Cu(II) from aqueous solution by micro-structured ZnO thin films
Mahsa Bagheri,Saeid Azizian,Babak Jaleh,Abdolkarim Chehregani 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4
Micro-structured thin films of ZnO and Zn(OH)2 on glass slides were prepared using microwave irradiation as a rapid and simple method. The effect of pH on the structure and composition of films were studied by scanning electron microscope and X-ray diffraction methods. Formation of flower-like ZnO structure starts with formation of nano-rods. The application of thin films as adsorbent was studied by Cu(II) adsorption of from aqueous solution. The adsorption equilibrium and kinetic data were modeled with classical and recently developed models. The obtained ZnO film is an effective adsorbent for removing of Cu(II) with high adsorption capacity of 692 mg/g.
Specification of Bacteriophage Isolated Against Clinical Methicillin-Resistant Staphylococcus Aureus
Ahmad Nasser,Reza Azizian,Mohsen Tabasi,Jamil Kheirvari Khezerloo,Fatemah Sadeghpour Heravi,Morovat Taheri Kalani,Norkhoda Sadeghifard,Razieh Amini,Iraj Pakzad,Amin Radmanesh,Farid Azizi Jalilian 질병관리본부 2019 Osong Public Health and Research Persptectives Vol.10 No.1
Objectives: The emergence of resistant bacteria is being increasingly reported around the world, potentially threatening millions of lives. Amongst resistant bacteria, methicillin-resistant Staphylococcus aureus (MRSA) is the most challenging to treat. This is due to emergent MRSA strains and less effective traditional antibiotic therapies to Staphylococcal infections. The use of bacteriophages (phages) against MRSA is a new, potential alternate therapy. In this study, morphology, genetic and protein structure of lytic phages against MRSA have been analysed. Methods: Isolation of livestock and sewage bacteriophages were performed using 0.4 μm membrane filters. Plaque assays were used to determine phage quantification by double layer agar method. Pure plaques were then amplified for further characterization. Sulfate-polyacrylamide gel electrophoresis and random amplification of polymorphic DNA were run for protein evaluation, and genotyping respectively. Transmission electron microscope was also used to detect the structure and taxonomic classification of phage visually. Results: Head and tail morphology of bacteriophages against MRSA were identified by transmission electron microscopy and assigned to the Siphoviridae family and the Caudovirales order. Conclusion: Bacteriophages are the most abundant microorganism on Earth and coexist with the bacterial population. They can destroy bacterial cells successfully and effectively. They cannot enter mammalian cells which saves the eukaryotic cells from lytic phage activity. In conclusion, phage therapy may have many potential applications in microbiology and human medicine with no side effect on eukaryotic cells.
Adsorption of anionic dyes from aqueous solution by iron oxide nanospheres
Maryam Khosravi,Saeid Azizian 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4
Magnetic iron oxide nanospheres were fabricated for removal of anionic dyes from aqueous solution. The iron oxide nanospheres are ferromagnetic and can be separated by an external magnetic field. The iron oxide has been synthesized with the solvothermal method. The prepared product was characterized by SEM and XRD methods. The adsorption of Reactive Orange (RO) and Reactive Yellow (RY) on to iron oxide nanospheres was investigated from both equilibrium and kinetic point of view and the results were modeled with appropriate equilibrium and kinetic models. The influences of solution pH and temperature on the removal efficiency were studied too.
Filterless and Sensorless Commutation Method for BLDC Motors
Rad, Shahin Mahdiyoun,Azizian, Mohammad Reza The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.4
This study presents a new sensorless commutation method for brushless direct current motors to replace Hall sensor signals with virtual Hall signals. The importance of the proposed method lies in the simultaneous elimination of the phase shifter and the low-pass filters, which makes the method simple and cost-effective. The method removes high ripple switching noises from motor terminals, thereby decreasing motor losses. The proposed method utilizes unfiltered line voltages with notches caused by current commutation. Hence, specific sign signals are defined to compensate for the effects of commutation noise. The proposed method is free from phase delay that originates from low-pass filters. The method directly produces virtual Hall signals, and thus, it can be interfaced with low-cost commercial commutation integrated circuits based on Hall sensors. Simulation and experimental results show the effectiveness and validity of the proposed method.
Fatemeh Seifikar,Saeid Azizian,Atefeh Nasri,Babak Jaleh 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-
Nanofluids are colloidal systems broadly used in solar-energy utilization. The main disadvantages ofnanofluids are their instability and time-consuming preparation methods, the aim of the present workis to introduce a nanofluid without the mentioned problems. Herein, two colloidal systems of vanadium including V/PEG (for the first time) and V/H2O nanofluidswere synthesized by laser ablation in liquid method in polyethylene glycol and water, respectively andutilized in light-to-heat conversion. V/PEG is more stable than V/H2O as the oxidation state of vanadiumis unchanged in polyethylene glycol but in water is changed until V2O5 is obtained. Unlike V/H2O, noagglomeration/precipitation takes place for V/PEG. Based on the images obtained from transmission electronmicroscopy, vanadium nanoparticles have different morphologies and sizes, helping V/PEG to absorbdifferent wavelengths, resulting in more heat generation. The surface temperature of V/PEG reached ffi 57℃ (DT ffi 30 ℃), under 60 min sunlight irradiation (0.9 Sun). The V/PEG was used at high light intensitiesand several successive heating–cooling cycles without losing its heat-generation performance. Differentcalculated thermo-physical parameters reveal that V/PEG is more eligible than V/H2O in photo-thermalconversion with several advantages: inexpensive and simple synthesis, dispersant-free, long-colloidalstability, high photo-thermal durability and high heat-generation efficiency.
Enhancement of methyl violet removal by modification of TiO2 nanoparticles with AgI
Shila Jafari,Babak Jaleh,Saeid Azizian 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.6
Nanostructured AgI/TiO2 was synthesized by deposition–precipitation method. The AgI/TiO2 nanoparticles with different size were characterized using XRD and TEM methods. In order to compare the activity of these nanoparticles for removal of environmental pollutants, the adsorption of methyl violet by particles was studied. The equilibrium adsorption data were fitted to the different isotherms. The equilibrium data show that the modification of TiO2 nanoparticles with AgI, leads to the higher adsorption capacity (more than twice) for methyl violet. The kinetic data for adsorption of methyl violet indicates that modification of TiO2 with AgI leads to a stable adsorption.
M. Shirzad Siboni,M. R. Samarghandi,S. Azizian,W. G. Kim,S. M. Lee 대한환경공학회 2011 Environmental Engineering Research Vol.16 No.2
The removal of hexavalent chromium from aqueous solutions onto modified holly sawdust was studied at varying initial hexavalent chromium concentrations, adsorbent doses, pHs and contact times. The removal of hexavalent chromium from aqueous solutions increased with increasing adsorbent dosage and contact time. The percentage of hexavalent chromium removed from the aqueous solutions decreased with increasing hexavalent chromium concentration and pH of the solution. The kinetics of the adsorption of hexavalent chromium onto modified holly sawdust was analyzed using pseudo first-order and pseudo second-order models. The pseudo second-order model described the kinetics of adsorption of hexavalent chromium. The Langmuir and Freundlich isotherm models were used for modeling of the adsorption equilibrium data. The Langmuir isotherm model well described the equilibrium data for the removal of hexavalent chromium by modified holly sawdust. The obtained maximum adsorption capacity was 18.86 mg/g at pH 7. The results showed that modified holly sawdust can be used as a low cost adsorbent for the treatment of aqueous solutions containing chromium.