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Showing 2 results for Rezanezhad
Investigating the Possibility of Producing Antibacterial Paper for Food Packaging with Rosemary (Rosmarinus Officinalis L.) Extract

Volume 19, Issue 133 (February 2023)
Abstract
Change in the food consumption’s pattern and the widespread use of the fast foods, as well as, the globalization of the food trade and the transportation of food over the long distances have brought great challenges to the safety and quality of the foods. One of the most important uses of the papers is the food packaging industry to keep the health and quality of the packaged materials from the production step to the customer. The extract of medicinal plants has the ability to create antibacterial properties. In this research, rosemary extract was used to produce the antibacterial papers. Extraction of plant was done by using soxhlet extractor and ultrasonic. In the soxhlet method, the dry powder was extracted at 4 and 6 hours and in the ultrasonic method, 40 and 60 powers were used for extraction. Then the papers were treated with plant extract prepared in two amounts of 15 and 20% based on the dry weight of the paper. The antibacterial properties of the papers were investigated with Escherichia coli and Staphylococcus aureus bacteria. All the papers treated with rosemary extracted by soxhlet method showed antibacterial property. Inhibition zone of bacteria was formed for both of them. The maximum diameter of the Inhibition zone for Escherichia coli and Staphylococcus aureus bacteria with 6 hours’ extraction and the consumption amount of 20% was 22 and 20 mm. In the treated paper with rosemary extracted by ultrasonic method, the maximum diameter of the Inhibition zone for Escherichia coli bacteria was 20 mm in 40A and 9 min. Also, the highest diameter of the Inhibition zone for Staphylococcus aureus bacteria was 20 mm in 40A and 9 min. Gas chromatography confirmed the presence of antibacterial substances including, Borneol, Camphor, and Bornyl acetate in rosemary extract
 
Effect of Simultaneous Use of Silica Nanoparticles and Heat Treatment on High-Cycle Bending Fatigue Lifetime in Piston Aluminum Alloy
M. Azadi, S. Rezanezhad, M. Zolfaghari, M. Azadi,
Volume 20, Issue 6 (June 2020)
Abstract
Aluminum-silicon alloys have vast applications in-vehicle components, such as the piston. Usually, such parts are under thermal and mechanical cyclic loadings, and therefore, they should have enough fatigue strength. For strengthening methods, the heat treatment and the addition of nanoparticles could be mentioned. In this research, the effect of the simultaneous use from SiO2 nanoparticles and the heat treatment was investigated on the high-cycle fatigue lifetime of the piston alloy, which is the novelty of this study. The stir-casting method was used for adding nanoparticles into the aluminum matrix, and the T6 heat treatment was done on samples. The microstructure was examined by the optical microscopy and also the field-emission scanning electron microscopy (FESEM), and high-cycle bending fatigue tests were performed, under fully-reversed loading conditions. Based on FESEM images, no agglomeration of nanoparticles was observed in the matrix. In addition, it was found that using SiO2 nanoparticles, heat treatment, and the combination of two approaches, caused to the improvement of the fatigue lifetime, for 304, 411 and 237%, respectively. According to high-cycle bending fatigue data, the fatigue strength coefficient of the piston alloy increased by the heat treatment, and the addition of nanoparticles.

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