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Optimal thermal design of anisotropic plates with arbitrary cutouts using genetic algorithm

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Theoretical & Applied Mechanics Letters 2022年第3期12卷 165-177页

作者： mohammad jafari Soheila Yari mohammad jafari Mechanical Engineering Department Shahrood University of TechnologyShahroodIran Faculty of Mechanical and Mechatronics Engineering Shahrood University of TechnologyShahroodIran

Anisotropic plates in different applications may have geometric defects such as openings and *** presence of the opening disturbs the heat flow,which creates significant thermal stress around the *** the heat flux is high enough,these extreme stresses can lead to structural *** article aims to obtain the optimal parameters for achieving the minimum value of the normalized stress near the cutout’s boundary in perforated anisotropic plates utilizing the genetic *** parameters include the curvature of opening’s corners,orientation angle of opening,fibers angle,heat flux angle,and opening’s *** plate is under heat flux,and the opening’s border is thermally *** stress distribution around the opening is calculated using Lekhnitskii’s complex variable method and complex potential *** genetic algorithm is then implemented to find the optimal values for design *** results show that by selecting the optimal parameters related to the anisotropic material and the opening’s geometry,the stress intensity factor of the perforated anisotropic plates is remarkably ***,this optimization algorithm can be extended to find the optimized parameters and achieve the optimal designs in anisotropic and isotropic perforated plates under thermal loadings.

关键词： Anisotropic materials Perforated plate Optimization Genetic algorithm Thermal stress Complex variable method Conformal mapping

Scleractinian coral communities of Hormuz Island in the PersianGulf

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Acta Oceanologica Sinica 2022年第12期41卷 48-57页

作者： Yamin Pouryousef Jafar Seyfabadi Hamid Rezai Alireza Mahvari mohammad Ali jafari Department of Marine Biology Faculty of Marine SciencesTarbiat Modares UniversityNoor 46417Iran Darya Negar Pars Consulting Engineers Tehran 14669Iran Department of Environment Hormozgan Provincial Directorate Bandar Abbas 79168Iran

The abundance and health of scleractinian coral communities of Hormuz Island were *** this purpose,we employed 20 m line intercept transects—12 in the intertidal zone and 15 subtidally to evaluate coral cover and community *** estimated dead coral coverage was 6.21%±0.81%,while live coral coverage was 16.93%±1.81%,considered as very ***,12 genera were recorded,of which Porites with 11.9%±1.4%live cover was the dominant,while Goniopora had the least cover(0.07%±0.08%).Based on Mann-Whitney U-test,live coral coverage,dead coral coverage,algal coverage,cover of other benthic organisms and abiotic components showed significant univariate differences between zones(p<0.05).The Spearman correlation test between the abundance of biotic and abiotic components indicated significant negative correlation of live coral and sand with zoantharian and significant positive correlation of algae and other benthic organisms with *** reef health indices used for the corals indicated that,in general,the environmental conditions were not suitable,which could be attributed to both natural and anthropogenic factors,the most important of which was zoantharian’overgrowth on the scleractinian corals in this region.

关键词： scleractinian corals zoantharian reef health indices Hormuz Island Persian Gulf

The Effect of Spironolactone Loading on the Properties of 3D-Printed Polycaprolactone/Gold Nanoparticles Composite Scaffolds for Myocardial Tissue Engineering

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Journal of Bionic Engineering 2024年第2期21卷 924-937页

作者： Sharareh Ghaziof Shahrokh Shojaei Mehdi Mehdikhani mohammad Khodaei Milad jafari Nodoushan Department of Biomedical Engineering Central Tehran BranchIslamic Azad UniversityTehran***Iran Stem Cells Research Center Tissue Engineering and Regenerative Medicine InstituteCentral Tehran BranchIslamic Azad UniversityTehran***Iran Department of Biomedical Engineering Faculty of EngineeringUniversity of IsfahanIsfahan***Iran Materials Engineering Group Golpayegan College of EngineeringIsfahan University of TechnologyGolpayegan87717-67498Iran Hard Tissue Engineering Research Center Tissue Engineering and Regenerative Medicine InstituteCentral Tehran BranchIslamic Azad UniversityTehran***Iran

Engineered cardiac constructs(ECC)aid in the progression of regenerative medicine,disease modeling and targeted drug delivery to adjust and aim the release of remedial combination as well as decrease the side effects of *** this research,polycaprolactone/gold nanoparticles(PCL/GNPs)three-dimensional(3D)composite scaffolds were manufactured by 3D printing using the fused deposition modeling(FDM)method and then coated with gelatin/spironolactone(GEL/SPL).Scanning electron microscopy(SEM)and Fourier transform-infrared spectroscopy(FTIR–ATR)were applied to characterize the ***,drug release,biodegradation,behavior of the myoblasts(H9C2)cell line,and cytotoxicity of the 3D scaffolds were *** microstructural observation of the scaffolds reported interconnected pores with 150–300µm in *** 3D scaffolds were degraded significantly after 28 days of immersion in stimulated body fluid(SBF),with the maximum rate of GEL-coated 3D *** release from cross-linked GEL coating demonstrated the excess of drug release over time,and according to the control release systems,the drug delivery systems(DDS)went into balance after the 14th *** addition,cell culture study showed that with the addition of GNPs,the proliferation of(H9C2)was enhanced,and with GEL/SPL coating the cell attachment and viability were improved *** findings suggested that PCL/GNPs 3D scaffolds coated with GEL/SPL can be an appropriate choice for myocardial tissue engineering.

关键词： Polycaprolactone Gold nanoparticles Drug delivery systems Spironolactone Cell behavior Myoblasts

Rumi: An Intelligent Agent Enhancing Learning Management Systems Using Machine Learning Techniques

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Journal of Software Engineering and Applications 2022年第9期15卷 325-343页

作者： Behafarid mohammad jafari Mengyuan Zhao Ali jafari Department of Electrical and Computer Engineering Indiana University-Purdue University Indianapolis Indianapolis USA Department of Instructional System Technology School of Education Indiana University Bloomington USA Department of Computer and Information Technology Indiana University-Purdue University Indianapolis Indianapolis USA

The dramatic improvement of information and communication technology (ICT) has made an evolution in learning management systems (LMS). The rapid growth in LMSs has caused users to demand more advanced, automated, and intelligent services. This paper discusses how Artificial Intelligence and Machine Learning techniques are adopted to fulfill users’ needs in a social learning management system named “CourseNetworking”. The paper explains how machine learning contributed to developing an intelligent agent called “Rumi” as a personal assistant in CourseNetworking platform to add personalization, gamification, and more dynamics to the system. This paper aims to introduce machine learning to traditional learning platforms and guide the developers working in LMS field to benefit from advanced technologies in learning platforms by offering customized services.

关键词： Learning Management Systems Intelligent Agents Artificial Intelligence Machine Learning

Numerical Study of Aeroacoustic Sound on Performance of Bladeless Fan

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 483-494页

作者： mohammad jafari Atta Sojoudi Parinaz Hafezisefat Aerospace Engineering Department Iowa State UniversityAmesUSA Mechanical Engineering Department University of TehranTehranIran Mechanical Engineering Department Iowa State UniversityAmesUSA

Aeroacoustic performance of fans is essential due to their widespread application. Therefore, the original aim of this paper is to evaluate the generated noise owing to different geometric parameters. In current study, effect of five geometric parameters was investigated on well performance of a Bladeless fan. Airflow through this fan was analyzed simulating a Bladeless fan within a 2 m×2 m×4 m room. Analysis of the flow field inside the fan and evaluating its performance were obtained by solving conservations of mass and momentum equations for aerodynamic investigations and FW-H noise equations for aeroacoustic analysis. In order to design Bladeless fan Eppler 473 airfoil profile was used as the cross section of this fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter and aspect ratio for circular and quadratic cross sections were considered. Validating acoustic code results, we compared numerical solution of FW-H noise equations for NACA0012 with experimental results. FW-H model was selected to predict the noise generated by the Bladeless fan as the numerical results indicated a good agreement with experimental ones for NACA0012. To validate 3-D numerical results, the experimental results of a round jet showed good agreement with those simulation data. In order to indicate the effect of each mentioned parameter on the fan performance, SPL and OASPL diagrams were illustrated.

关键词： Bladeless fan Computational fluid dynamic (CFD) Aeroacoustic performance Ffowcs Williams and Hawkings (FW-H) formulation

Application of perfectly matched layer to soil-foundation interaction analysis

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 753-768页

作者： mohammad Davoodi Abbas Pourdeilami Hosein Jahankhah mohammad Kazem jafari International Institute of Earthquake Engineering and Seismology TehranIran

Despite of the limitation in modeling infinite space, the finite element method(FEM) is one of the most used tools to numerically study the geotechnical problems regarding the capacity of simulating different geometries, conditions and material behaviors. A kind of absorbing layer named perfectly matched layer(PML) has been applied to modeling the radiation damping using FEM, which makes the dynamic analysis of soil-structure interaction more accurate. The PML is capable of absorbing incident waves under any angle and frequency, ensuring them to pass through the model boundaries without *** this context, a new FEM program has been written and the PML formula has been implemented by rewriting the dynamic equation of motion and deriving new properties for the quadrilateral *** analysis of soil-foundation interaction by applying the PML is validated by the evaluation of impedance/compliance functions for different ground conditions. The results obtained from the PML model match the extended mesh results, even though the domain is small enough that other types of absorbing boundaries can reflect waves back to the foundation. The mechanism of the wave propagation in the region shows that the forced vibrations can be fully absorbed and damped by the boundaries surrounded by PMLs which is the role of radiation damping in FEM modeling.

关键词： Perfectly matched layer (PML) Finite element method (FEM) Wave propagation Impedance/compliance

Woody Species Diversity and Forest Structure from Lowland to Montane Forest in Hyrcanian Forest Ecoregion

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Journal of Mountain Science 2013年第4期10卷 609-620页

作者： Seyed mohammad jafari Shahin ZARRE Seyed Kazem ALAVIPANAH School of Biology and Center of Excellence in Phylogeny of Living Organisms College of Science University of TehranP.O. Box 14155-6455 Tehran Iran School of Biology and Center of Excellence in Phylogeny of Living Organisms College of Science University of TehranTehran Iran Department of Cartography Faculty of Geography University of TehranTehran Iran

Alborz Mountains host Caspian Hyrcanian forest ecoregion along the northern slopes and forest steppe ecoregion in highlands. Hyrcanian forest covers the southeastern part of Caucasus biodiversity hotspot and is of great biogeographic importance. Altitudinal pattern and correlation between woody species biodiversity (DIV), forest structure ((stem density (DEN), mean basal area (MBA) and mean height class (MHC)) and disturbance (DIS) were explored along 2,400 m altitudinal gradient in Hyrcanian relict forest, Central Alborz Mountains. Vegetation changes from lowland forest (LoF) to mid- altitude forest (MiF) and montane forest (MoF) in this area. The altitudinal gradient was divided into twelve 200 m elevational belts. Point centered quarter method (PCQM) with 96 sampling points and 83 vegetation samples by plot method (PM) were used to record field data. Shannon-Wiener index and Pearson coefficient were used for diversity and correlation analysis. The results showed that DEN decreased linearly, MBA and MHC showed relatively hump shaped and DIS showed a reverse hump shaped pattern of change along altitudinal gradient. Woody species diversity decreased non-steadily from LoF to MoF. Transitional vegetations of Carpinus-Fagus and Fagus-Quercus represented higher diversity of woody taxa compared to adjacent homogenous communities. Significant correlation was observed between altitude and all parameters: DEN with MBA, DIS and DIV; MBA with DIS; MHC with DIS along with DIV; and DIS with DIV at the study area scale. Surprisingly,correlation between studied parameters differed within each vegetation type. Altitude probably acts as a proxy for human and environmental driving forces in this area. Stability of warm and wet condition, season length, soil depth along with forest accessibility probably influences the altitudinal pattern of the studied parameters. Disturbance affects forest structure and consequently diversity; especially in lowlands. The obtained results recommend

关键词：物种多样性山地森林木本植物森林结构生态区低地 Pearson相关系数森林生物多样性

Complexation of Sm^(3+) and pamidronate: A DFT study

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Journal of Rare Earths 2015年第3期33卷 310-319页

作者： Masoud Arabieh mohammad Hassan Khodabandeh mohammad Hossein Karimi-jafari Carlos Platas-Iglesias Karim Zare Computational Chemistry Laboratory NSTRI 11365-8486 Tehran Iran Department of Chemistry Faculty of Science Shahid Beheshti University G.C. Evin 19839-63113 Tehran Iran Department of Bioinformatics Institute of Biochemistry and Biophysics University of Tehran 13145-1384 Tehran Iran Departamento de Química Fundamental Universidade da Coru?a Campus da Zapateira-Rúa da Fraga 10 15008 A Coru?a Spain

We reported a quantum mechanical study of the complexes formed between Sm3＋ and the bisphosphonate ligand pamidronate in aqueous solution. According to available experimental p K a values pamidronate was expected to exist in aqueous solution, at physiologically relevant p H, in its di- and tri-protonated forms（denoted by H3 L and H2L）. The most stable structures of the ligands and Sm3＋ complexes were found by using a detailed analysis of the conformational space with semiempirical and DFT methods. The results showed that both H2 L and H3 L bisphosphonates acted as a tridentate ligands in their complexes with Sm3＋. The addition of explicit water molecules to the coordination sphere of the metal not only gave different coordination numbers for H2 L and H3 L complexes（CN=9 and 10）, but also provided different trends in stabilization energies. The results highlighted the importance of considering not only an explicit first coordination shell, but also a second hydration shell, for an adequate description of this type of complexes in aqueous solution.

关键词： samarium radiopharmaceutical bisphosphonates solvent effects rare earths

QUASI-PERMUTATION REPRESENTATIONS OF ALTERNATING AND SYMMETRIC GROUPS

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Acta Mathematica Scientia 2007年第2期27卷 297-300页

作者： Houshang Behravesh mohammad Hossein jafari Department of Mathematics University of Urmia UrmiaIran Department of Mathematics University of Tabriz TabrizIran

The quantities c（G）, q（G） and p（G） for finite groups were defined by H. Behravesh. In this article, these quantities for the alternating group An and the symmetric group Sn are calculated. It is shown that c（G... 详细信息

关键词： Quasi-permutation representations alternating groups symmetric groups character theory