Saeed Mortazavi
@iau-shahrood.ac.ir
chemical engineering
Azad university - Shahrood Branch
RESEARCH INTERESTS
polymer engineering
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Abdolnaser Gharehdashli, Saeed Mortazavi, and Hamed Rashidi
Pleiades Publishing Ltd
M. Khosravi, M. Khoshvaght-Aliabadi, and S. Mortazavi
Springer Science and Business Media LLC
The current experimental study focuses on designing novel shapes of transverse turbulators to improve the performance of solar air heaters. Fourteen designs are derived from the original case having length × width × thickness of 30 mm × 15 mm × 0.8 mm. These turbulators are tested in a rectangular channel, and the thermal and hydraulic transport performances of the fitted channel are compared with those obtained for the vacant channel. Although the novel geometries may provide a weaker thermal characteristic through the channel, the penalty in the hydraulic characteristic is decreased significantly compared to the original shape, leading to better overall hydrothermal performances. It is found that the novel designs of transverse turbulators own lower values of heat transfer coefficient, that is ranging from 12.1% to 45.2%, whereas the pressure drop decreases within the range of 48%–91% at the studied Reynolds numbers (Re = 1643, 3286, and 4929). The results show that the Nusselt number ratio (Nufitted/Nuclear) gets reducing trend with increasing Re, while the friction factor ratio (ffitted/fclear) gets increasing trend. An appropriate tradeoff between thermal and hydraulic characteristics is established by using a specific design which presents minimum values of pressure drop and maximum values of the performance index. The highest index of 1.69 is recorded for this turbulator design at Re = 1643.
R. Mortazavi, S. Mortazavi, and A. Troncoso
Springer Science and Business Media LLC
This paper introduces different types of regression trees for viscosity property forecasting in polymer solutions. Although regression trees have been extensively used in other fields, they do not have been explored to predict the viscosity. One key issue in the context of materials science is to determine a priori which characteristics must be included to describe the prediction model due to a large number of molecular descriptors is obtained. To deal with this, we propose a wrapper method to select the features based on regression trees. Thus, we use regression trees to evaluate different subsets of attributes and build a model from the subset of features that achieved the minimum error. In particular, the performance of eight regression tree algorithms, including both linear and non-linear models, is evaluated and compared to other forecasting approaches using a dataset composed of 64 polymers and 2962 molecular descriptors. The results show that regression trees with nearest neighbors based local models in leaves predict with high accuracy. Moreover, results have been compared to other forecasting approaches such as multivariate linear regression, neural networks and support vector machines showing remarkable improvements in terms of accuracy.
Kiyoumars Labani Motlagh, Javad Seyfi, Hossein Ali Khonakdar, and Saeed Mortazavi
Springer Science and Business Media LLC
Kiyoumars Labani Motlagh, Javad Seyfi, Hossein Ali Khonakdar, and Saeed Mortazavi
Wiley
Abdolnaser Gharehdashli, Saeed Mortazavi, and Hamed Rashidi
Wiley
Majid Shojaee Kang Sofla, Saeed Mortazavi, and Javad Seyfi
Elsevier BV
The synergistic plasticization/compatibilization effect of poly(ethylene glycol)/glycerol is reported for poly(vinyl alcohol) (PVA)/chitosan blends. The optimum concentration of PEG was first determined by preparation and characterization of PVA/PEG blends at different ratios (9:1, 6:1 and 3:1). The PVA/chitosan blends, plasticized with PEG, glycerol, and their combination, were also prepared and characterized. Fourier transform infrared results suggested that PEG enhances the compatibility of PVA/chitosan blends. This claim was further confirmed by the morphological results. However, PEG had a detrimental effect on the crystallinity of PVA/chitosan blends. The combination of glycerol and PEG caused a five-time enhancement in the elongation at break values as compared with the blend plasticized with glycerol. The antibacterial properties against E. coli were also evaluated. All in all, the high antibacterial properties of the blend films along with good mechanical and morphological properties could be beneficial in wound dressing and food packaging applications which need further investigation.
Khoshvaght-Aliabadi Morteza and Saeid Mortazavi
Informa UK Limited
ABSTRACT The current work reports an experimental study on hydrothermal improvement in a chevron plate-fin heat exchanger combined with holes and winglets. The experiments are performed for water flow through a test square duct fitted with enhanced chevron plate-fins for the Reynolds number from 4000 to 10000. Characteristics of the enhanced chevron plate-fins include three waviness aspect ratios and four different arrangements of holes and winglets at a constant diameter of holes and width/height of winglets. An overall performance factor is applied to obtain the optimal geometry. Then, only the optimal geometries are applied to find out the effect of Al2O3/water nanofluid flow on the performance of a plate-fin heat exchanger. In comparison to simple chevron plate-fins, the enhanced ones would increase the Nusselt number by a factor between 1.05% and 1.6%. In addition, simultaneous application of the optimal enhanced chevron plate-fins and the nanofluid could increase the Nusselt number. The best working conditions of this system are detected for the nanofluid at a weight fraction of 0.3%.
Seyyed Ali Hosseini, Saeed Mortazavi, and Jafar Izadi Nia
Informa UK Limited
ABSTRACT Polyurethane nanocomposites based on hydroxyl-terminated polybutadiene and graphene with different formulations were cured using toluene diisocyanates. The rheological, physical, mechanical, thermal and morphological properties of the nanocomposites were investigated. The viscosity of the samples increased rapidly with graphene content. However, the kinetic rate of the curing process was lower for the nanocomposites in comparison to the neat matrix. The mechanical properties showed a successive increase in the tensile strength and reduction in elongation at break with an increase in graphene content. The highest value of the modulus, density and degradation temperature was obtained for the nanocomposite with 1 wt-% graphene. The hardness properties of the nanocomposites enhanced with curing time. The morphological properties of the nanocomposites are also investigated with the field emission scanning electron microscopy which confirmed the agglomeration occurrence at the high graphene contents.
Saeed Mortazavi
Elsevier BV
Abstract The flow of pseudoplastic power-law fluids with different flow indexes at a microchannel plate was studied using computational fluid dynamic simulation. The velocity distribution along the microchannel plate and especially in the microchannel slits, flow pattern along the outlet arc and the pressure drop through the whole of microchannel plate were investigated at different power-law flow indexes. The results showed that the velocity profile in the microchannel slits for low flow index fluids was similar to the plug flow and had uniform pattern. Also the power-law fluids with lower flow indexes had lower stagnation zones near the outlet of the microchannel plate. The pressure drop through the microchannel plate showed huge differences between the fluids. The most interesting result was that the pressure drops for power-law fluids were very smaller than that of Newtonian fluids. In addition, the heat transfer of the fluids through the microchannel with different channel numbers in a wide range of Reynolds number was investigated. For power-law fluid with flow index ( n = 0.4), the Nusselt number increases continuously as the number of channels increases. The results highlight the potential use of using pseudoplastic fluids in the microheat exchangers which can lower the pressure drop and increase the heat transfer efficiency.
RECENT SCHOLAR PUBLICATIONS
MOST CITED SCHOLAR PUBLICATIONS
Publications
Labani Motlagh, Kiyoumars; Seyfi, Javad; Khonakdar, Hossein Ali; Mortazavi, Saeed; Vinyl ester/silica aerogel nanocomposite coatings with enhanced hydrophobicity and corrosion protection properties Polymers for Advanced Technologies 32 5 2176-2184 2021 Wiley Online Library
Mortazavi, R; Mortazavi, S; Troncoso, A; Wrapper-based feature selection using regression trees to predict intrinsic viscosity of polymer Engineering with Computers 44209 2021 Springer
Gharehdashli, Abdolnaser; Mortazavi, Saeed; Rashidi, Hamed; Photodegradation of lowâ€density polyethylene with prooxidant and photocatalyst Journal of Applied Polymer Science 137 34 48979 2020 Wiley Online Library
Sofla, Majid Shojaee Kang; Mortazavi, Saeed; Seyfi, Javad; Preparation and characterization of polyvinyl alcohol/chitosan blends plasticized and compatibilized by glycerol/polyethylene glycol Carbohydrate polymers 232 115784 2020 Elsevier
Morteza, Khoshvaght-Aliabadi; Mortazavi, Saeid; Combined effects of holes and winglets on chevron plate-fins to enhance the performance of a plate-fin heat exchanger working with nanofluid Experimental Heat Transfer 32 6 584-599 2019 Taylor & Francis
Hosseini, Seyyed Ali; Mortazavi, Saeed; Nia, Jafar Izadi; Preparation and characterisation of hydroxyl-terminated polybutadiene-based polyurethane/graphene nanocomposites Plastics, Rubber and Composites 47 6 241-248 2018 Taylor & Francis
Haghighat, Fatemeh; Mokhtary, Masoud; Mortazavi