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Effect of milling atmosphere on structural and magnetic properties of Ni-Zn ferrite nanocrystalline

Chinese Physics B 2015年第4期24卷 481-490页

作者： Abdollah Hajalilou Mansor Hashim Reza Ebrahimi-Kahrizsangi mohamad taghi masoudi Material Synthesis and Characterization Laboratory Institute of Advanced Technology (ITMA)Universiti Putra Malaysia Advanced Materials Research Center Materials Engineering Department Najafabad Branch Islamic Azad University

Powder mixtures of Zn, NiO, and Fe2O3 are mechanically alloyed by high energy ball milling to produce Ni-Zn ferrite with a nominal composition of Ni0.36Zn0.64Fe2O4. The effects of milling atmospheres （argon, air, and oxygen）, milling time （from 0 to 30 h） and heat treatment are studied. The products are characterized using x-ray diffractometry, field emission scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy, and transmitted electron microscopy. The results indicate that the desired ferrite is not produced during the milling in the samples milled under either air or oxygen atmospheres. In those samples milled under argon, however, Zn/NiO/Fe2O3 reacts with a solid-state diffusion mode to produce Ni-Zn ferrite nanocrystalline in a size of 8 nm after 30-h-milling. The average crystallite sizes decrease to 9 nm and 10 nm in 30-h-milling samples under air and oxygen atmospheres, respectively. Annealing the 30-h-milling samples at 600℃ for 2 h leads to the formation of a single phase of Ni-Zn ferrite, an increase of crystallite size, and a reduction of internal lattice strain. Finally, the effects of the milling atmosphere and heating temperature on the magnetic properties of the 30-h-milling samples are investigated.

关键词： Ni-Zn ferrite nanocrystalline mechanical alloying milling atmosphere milling time magnetic property

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Modeling and experimental studies of methyl methacrylate polymerization in a tubular reactor

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Chinese Journal of Chemical Engineering 2016年第12期24卷 1655-1663页

作者： mohamad-taghi Rostami Ali Daneshgar Department of Engineering Mohaghegh Ardabili University Daneshgah Street Ardabil lran

In this study, rheological examination of the mixture of a tubular reactor in which methyl methacrylate was polymerized has been studied. The n(flow behavior index) value of Power Law Model of mixture contained in the reactor has been determined within the span of 0.3492 to 0.9889 by curve fitting. Employing these numerical data for velocity profile, the reactor has been modeled. Moreover, the functions of the reactor have been compared in the three modes of plug, mixed and laminar flow. The results obtained in this research indicate that the polymethyl methacrylate mixture contained in the reactor is pseudo-plastic. Moreover, as the conversion grows, the velocity profile starts as a parabolic profile and approaches the plug mode; although it never reaches the plug. The other conclusions borne in this study indicate that when the reactor's radius is decreased, the conversion rate grows. However, as decreasing the radius would also reduce the productions rate, this procedure is not economical. Finally, in this modeling, the amount of conversion is equal to 56.47% at the end and according to its laboratory proportion which is 55.88%, it has reached the conclusion that the modeling duly undertaken is applicable and valid.

关键词： Conversion Laminar flow MMA Modeling Tubular reactor

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PREPARATION, CHARACTERIZATION AND ADHESIVE PROPERTIES OF DI-AND TRI-HYDROXY BENZOYL CHITOSAN NANOPARTICLES

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Chinese Journal of Polymer Science 2013年第4期31卷 649-659页

作者： mohamad taghi taghizadeh Ali Bahadori Department of Physical Chemistry Faculty of ChemistryUniversity of TabrizTabrizIran

Modified chitosans with 3,4-di-hydroxy benzoyl groups （CS-DHBA） and 3,4,5-tri-hydroxy benzoyl groups （CS- THBA） were synthesized and their nanoparticles were prepared via ionic crosslinking by tripolyphosphate （TPP）. The chemical structure and degree of substitution （DS） of di- and tri-hydroxy benzoyl chitosans are determined by FTIR and IH- NMR spectroscopy. The morphology of particles, size distribution and zeta potential of nanoparticles were studied using transmission electron microscopy （TEM） and dynamic light scattering （DLS）, respectively. The mean diameters of particles of CS-DHBA and CS-THBA nanoparticles were 144 nm and 112 nm, respectively. It was found that the particles size decreased slightly with decreasing the degree of substitution and increasing degree of deacetylation （DD）, due to increasing of ionic crosslinking of ammonium ions and polyanions of tripolyphosphate. The TEM photographs of CS-DHBA show that these particles are spherical in shape, but the particles of CS-THBA show some aggregation. In addition, the solubility and the mechanical properties of the prepared modified chitosans and their nanoparticles were evaluated for bio-adhesive and biomedical application. The results of solubility tests indicated that, the CS-DHBA and CS-THBA have higher solubility at pH 〉 7 comparing to CS. Also the CS-DHBA, CS-THBA and their nanoparticles showed a significant adhesive capacity and enhanced tensile strength and tensile modulus.

关键词： Nanoparticles Di- and tri-hydroxy benzoyl chitosans Ionic cross linking Solubility Adhesive properties.

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Modeling and Simulation of High Power Ultrasonic Process in Preparation of Stable Oil-in-Water Emulsion

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Journal of Software Engineering and Applications 2011年第4期4卷 259-267页

作者： Javad Sargolzaei mohamad taghi Hamed Mosavian Attieh Hassani Department of Chemical Engineering Ferdowsi University of Mashhad

The aims of this research are to study application of high power ultrasound in preparation of stable oil-in-water emulsion. The effect of pH, ionic strength, pectin, Guar gum, lecithin, egg yolk, and xanthan gum as well as the time of sonication, temperature and viscosity of oil-water mixture on the specific surface area and size of droplets, and creaming index of the emulsion samples was investigated. The experimental data were analyzed with Taguchi method and optimum conditions were determined. In addition, an adaptive neuro-fuzzy inference system (ANFIS) was employed to modeling and categorizes the properties of the resulted emulsion. The results showed that increasing sonication time narrowed the range of droplets size distribution. Pectin and xanthan enhanced the stability of emulsion, although they had different impacts on the emulsion stability when used individually or together. Guar gum improved the viscosity of the continuous phase. Emulsions stabilized by egg yolk were found to be stable to droplet flocculation at pH 3 and at relatively low salt concentrations.

关键词： Ultrasound Process Stable Oil Egg Yolk Emulsion ANFIS FIS

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Comparison of Using an Electronic System and Conventional Monitoring Method for Monitoring the Quality of Drinking Water and Defects Discovery in Rural Area Water Distribution Network of Abarkouh, Iran

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Health 2015年第1期7卷 35-40页

作者： Reza Ali Fallahzadeh Maryam Gholami Elham Madreseh Mohammad taghi Ghaneian mohamad Hadi Farahzadi Ali Akbar Askarnejad Shahram Sadeghi Department of Environmental Health Engineering School of Public Health Shahid Sadoughi University of Medical Sciences Yazd Iran Department of Environmental Health Engineering Abarkouh Paramedical School Shahid Sadoughi University of Medical Sciences Yazd Iran Department of Epidemiology and Biostatistics School of Health Tehran University of Medical Sciences Tehran Iran Department of Neuroscience School of Advanced Technologies in Medicine Tehran University of Medical Sciences Tehran Iran Abarkouh Health Network Shahid Sadoughi University of Medical Sciences Yazd Iran Department of Environmental Health Engineering School of Public Health Student Research Committee Kurdistan University of Medical Sciences Sanandaj Iran

The used water for human consumption must be free of microorganisms and chemicals that cause risk in the human health. In this study, water quality of 18 rural area of Abarkouh was determined and compared the conventional monitoring method (According to ISIR (Institute of Standards and Industrial Research of Iran), 1053 and 4208) and use of electronic system method (Patent in industrial property general office of Iran, 77815). Free chlorine monitoring and pH test done by health workers in the conventional method and the results will be sent to the Health Network monthly. Sampling for microbiological testing is done monthly based on population (According to ISIR, 4208). On the electronic system, the procedure is also done by health workers, but the result will be sent to the receiver device by using a cell phone. According to the chlorine test results if the free chlorine residual reported zero, microbiological sampling was done by a health expert. Finally, the number of chlorine test and microbiological sampling and the results of these experiments collected in the both methods and recorded in SPSS 22 then were analyzed by using chi-square test and Fisher exact test. The result of microbiological experiments shows that the sampling rate decreased 29% in using of electronic system method in comparison to the conventional monitoring method while the number of microbial defect detection increased 19% in drinking water networks monitoring by electronic system. Using of electronic system monitoring can reduce the rate and cost of microbiological sampling and its experiments and increase accuracy of these tests, in this way it will increase the quality and safety of drinking water in distribution network in small and dispersed rural communities.

关键词： Water Distribution Network Monitoring Microbiological Experiments Water Quality Rural Area

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