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Petroleum Science 2019年第6期16卷 1403-1416页

作者： Aboozar Soleymanzadeh Saeed Parvin shahin Kord Ahwaz Faculty of Petroleum Petroleum University of Technology(PUT)AhwazIran

Rock typing is an important tool in evaluation and performance prediction of *** techniques such as flow zone indicator(FZI),FZI~*and Winland methods are used to categorize reservoir rocks into distinct rock ***,these methods are applied to petrophysical data that are measured at a pressure other than reservoir *** the pressure changes the pore structure of rock,the effect of overburden pressure on rock typing should be *** this study,porosity and permeability of 113 core samples were measured at five different *** investigate the effect of pressure on determination of rock types,FZI,FZI~*and Winland methods were *** indicated that although most of the samples remain in the same rock type when pressure changes,some of them show different *** are related to the mineralogy and changes in pore system of the samples due to pressure ***,the number of rock types increases with increasing ***,the effect of overburden pressure on determination of rock types is more clearly observed in the Winland and FZI~****,results revealed that a more precise reservoir dynamic simulation can be obtained by considering the reservoir rock typing process at reservoir conditions.

关键词： Overburden pressure Carbonate rocks Rock type Reservoir quality index Flow zone indicator Winland method

Mechanical and corrosion properties of graphene nanoplatelet–reinforced Mg–Zr and Mg–Zr–Zn matrix nanocomposites for biomedical applications

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Journal of Magnesium and Alloys 2022年第2期10卷 495-514页

作者： Mohammad shahin Cuie Wen Khurram Munir Yuncang Li School of Engineering RMIT UniversityMelbourneVictoria 3001Australia

Magnesium(Mg)-based biomaterials have gained acceptability in fracture fixation due to their ability to naturally degrade in the body after fulfilling the desired ***,pure Mg not only degrades rapidly in the physiological environment,but also evolves hydrogen gas during *** this study,Mg0.5Zr and Mg0.5ZrxZn(x=1–5 wt.%)matrix nanocomposites(MNCs)reinforced with different contents(0.1–0.5 wt.%)of graphene nanoplatelets(GNP)were manufactured via a powder metallurgy technique and their mechanical and corrosion properties were *** increase in GNP concentration from 0.2 wt.%to 0.5 wt.%added to Mg0.5Zr matrices resulted in decreases in the compressive yield strength and corrosion resistance in Hanks’Balanced Salt Solution(HBSS).On the other hand,a higher concentration(4–5 wt.%)of Zn added to Mg0.5Zr0.1GNP resulted in an increase in ductility but a decrease in compressive yield ***,an addition of 0.1 wt.%GNPs to Mg0.5Zr3Zn matrices gave excellent ultimate compressive strength(387 MPa)and compressive yield strength(219 MPa).Mg0.5Zr1Zn0.1GNP and Mg0.5Zr3Zn0.1GNP nanocomposites exhibited 29%and 34%higher experimental yield strength,respectively,as compared to the theoretical yield strength of Mg0.5Zr0.1GNP calculated by synergistic strengthening mechanisms including the difference in thermal expansion,elastic modulus,and geometry of the particles,grain refinement,load transfer,and precipitation of GNPs in the Mg *** corrosion rates of Mg0.5Zr1Zn0.1GNP,Mg0.5Zr3Zn0.1GNP,Mg0.5Zr4Zn0.1GNP,and Mg0.5Zr5Zn0.1GNP measured using potentiodynamic polarization were 7.5 mm/y,4.1 mm/y,6.1 mm/y,and 8.0 mm/y,***,hydrogen gas evolution tests also demonstrated that Mg0.5Zr3Zn0.1GNP exhibited a lower corrosion rate(1.5 mm/y)than those of Mg0.5Zr1Zn0.1GNP(3.8 mm/y),Mg0.5Zr4Zn0.1GNP(1.9 mm/y),and Mg0.5Zr5Zn0.1GNP(2.2 mm/y).This study demonstrates the potential of GNPs as effective nano-reinforcement particulates for improv

关键词： Biodegradation Graphene nanoplatelet Magnesium metal matrix composite Mg–Zr–Zn alloy Strengthening mechanism

A Review on Self-healing in Modern Power Distribution Systems

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Journal of Modern Power Systems and Clean Energy 2023年第6期11卷 1719-1733页

作者： Seyed Ali Arefifar Md shahin Alam Abdullah Hamadi IEEE Department of Electrical and Computer Engineering Oakland UniversityRochesterUSA Department of Energy and Technology Odessa CollegeOdessaUSA School of Engineering and Technology Western Illinois UniversityMacombUSA

The ever-increasing dependence on electrical power has posed more challenges to power system engineers to deliver secure, stable, and sustained energy to electricity consumers. Due to the increasing occurrence of short-and long-term power interruptions in the power system, the need for a systematic approach to mitigate the negative impacts of such events is further manifested. Self-healing and its control strategies are generally accepted as a solution for this concern. Due to the importance of self-healing subject in power distribution systems, this paper conducts a comprehensive literature review on self-healing from existing published papers. The concept of self-healing is briefly described, and the published papers in this area are categorized based on key factors such as self-healing optimization goals, available control actions, and solution methods. Some proficient techniques adopted for self-healing improvements are also classified to have a better comparison and selection of methods for new investigators. Moreover, future research directions that need to be explored to improve self-healing operations in modern power distribution systems are investigated and described at the end of this paper.

关键词： Self-healing distributed generator renewable energy source microgrid optimization reconfiguration service restoration automation system

Deuteron electromagnetic form factors and tensor polarization observables in the framework of the hard-wall AdS/QCD model

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Chinese Physics C 2023年第1期47卷 55-62页

作者： Narmin Huseynova shahin Mamedov Jannat Samadov Institute for Physical Problems Baku State UniversityZ.Khalilov 23BakuAZ-1148Azerbaijan Institute of Physics Azerbajan National Academy of SciencesH.Javid 33BakuAZ 1143Azerbajan Shamakhy Astrophysical Observatory Azerbajan National Academy of SciencesH.Javid 115BakuAZ 1000Azerbaijan

We study the electromagnetic form factors and tensor polarization observables of the deuteron in the framework of the hard-wall AdS/QCD *** find a profile function for the bulk twistτ=6 vector field,which describes the deuteron on the boundary and fix the infrared boundary cut-off of AdS space in accordance with the ground state mass of the *** obtain the deuteron charge monopole,quadrupole,and magnetic dipole form factors and tensor polarization observables from the bulk Lagrangians for the deuteron and photon field *** plot the momentum transfer dependence of the form factors and tensor polarization observables and compare our numerical results with those in the soft-wall model and experimental data.

关键词： deuteron electromagnetic form factors structure functions tensor polarization observables hard-wall model

Study on failure mechanism of room and pillar with different shapes and configurations under uniaxial test and numerical simulation compression using experimental test and numerical simulation

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Underground Space 2023年第2期9卷 105-121页

作者： Vahab Sarfarazi Nima Babanouri shahin Fattahi Kaveh Asgari Department of Mining Engineering Hamedan University of TechnologyHamedanIran Department of Mining Engineering Shahid Bahonar University of KermanKermanIran

Experimental and discrete element methods were used to investigate the failure behavior of room and pillar with different configura-tions under uniaxial *** samples with dimension of 15 cm×15 cm×5 cm were *** the specimens,rooms and pillars with different configurations were *** room dimension was 1 cm×1 cm,and the pillar dimension was according to the room *** different configurations were chosen for rooms and *** axial load was applied to the model by rate of 0.05 mm/*** results show that the failure process was mostly governed by both the non-persistent joint angle and joint *** compressive strength of the specimens was related to the fracture pattern and failure mechanism of the *** was shown that the shear behaviour of pillars was related to the number of the induced tensile cracks,which increased by increasing the room *** compressive strength of samples increased with the increase of the room *** failure pattern and failure strength are similar in both methods,i.e.,the experimental testing and the numerical simulation.

关键词： PFC2D Physical test Rock pillar

Hydrothermal analysis of non-Newtonian fluid flow(blood)through the circular tube under prescrib e d non-uniform wall heat flux

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Theoretical & Applied Mechanics Letters 2022年第4期12卷 275-285页

作者： shahin Faghiri shahin Akbari Mohammad Behshad Shafii Kh.Hosseinzadeh Department of Mechanical Engineering Sharif University of TechnologyTehranIran Sharif Energy Water and Environment Institute(SEWEI)TehranIran

The present article aims to investigate the Graetz-Nusselt problem for blood as a non-Newtonian fluid obeying the power-law constitutive equation and flowing inside the axisymmetric tube subjected to nonuniform surface heat *** the flow field is determined by solving the continuity and the momentum equations,the energy equation is handled by employing the separation of variables *** resulting Eigen functions and Eigen values are numerically calculated using MATLAB built-in solver *** analysis is first conducted for the situation of constant heat flux and subsequently generalized to apply to the case of sinusoidal variation of wall heat flux along the tube length,using Duhamel’s ***,an approximate analytic solution is determined,employing an integral approach to solve the boundary layer *** respect to the comparison,the results of approximate solution display acceptable congruence with those of exact solution with an average error of 7.4%.Interestingly,with decreasing the power-law index,the discrepancy between the two presented methods significantly ***,the influences of the controlling parameters such as surface heat flux and power-law index on the non-Newtonian fluid flow’s thermal characteristics and structure are elaborately *** is found that switching from constant wall heat flux to non-uniform wall heat flux that sinusoidally varies along the tube length significantly improves the simulation’s accuracy due to the better characterization of the heat transport phenomenon in non-Newtonian fluid flow through the *** the presence of sinusoidally varying wall heat flux with an amplitude of 200 W/m 2 and when the power-law index is 0.25,the maximum arterial wall temperature is found to be about 311.56 K.

关键词： Non-newtonian fluid Power-law model Non-uniform heat flux Analytical solution

Finite element analysis and modeling of water absorption by date pits during a soaking process

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第7期11卷 482-488页

作者： Motahareh WAEZI-ZADEH Ahmad GHAZANFARI shahin NOORBAKHSH Horticultural Research Institute Shahid Bahonar University of Kerman

Date pits for feed preparation or oil extraction are soaked in water to soften before milling or extrusion. Knowledge of water absorption by the date pits helps in better managing the soaking duration. In this research, the process of water absorption by date pits was modeled and analyzed using Fick's second law of diffusion, finite element approach, and Peleg model. The moisture content of the pits reached to its saturation level of 41.5% (wet basis) after 10 d. The estimated coefficient of diffusion was 9.89×10-12 m2/s. The finite element model with a proposed ellipsoid geometry for a single date pit and the analytical model fitted better to the experimental data with R2 of 0.98. The former model slightly overestimated the moisture content of the pits during the initial stages of the soaking and the latter model generally underestimated this variable through the entire stages of soaking process.

关键词： Date pits Soaking Water absorption Modeling

Evaluation of copper removal efficiency using water treatment sludge

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Water Science and Engineering 2019年第1期12卷 37-44页

作者： Shimaa A.shahin Mohamed Mossad Moharram Fouad Public Works Engineering Department Faculty of Engineering Mansoura University

Large quantities of sludge are produced during water treatment processes. Recently, sludge has been treated as waste and disposed of in landfills, which increases the environmental burdens and the operational cost. Therefore, sludge reuse has become a significant environmental issue. In this study, adsorption of copper ions (Cu^2+) onto calcined sludge was investigated under various operational conditions (with varying temperature, Cu^2+ initial concentration, pH, and sludge dosage). The prepared sludge material was characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and Brunauer-Emmett-Teller (BET) surface area. The sorption capacity of sludge was directly proportional to the initial Cu^2+ concentration and inversely proportional to the sludge dosage. The optimum operational pH and solution temperature were 6.6 and 80℃, respectively. The experimental results followed a Langmuir isotherm and pseudo-first-order adsorption kinetics. Thermodynamic parameters such as activation energy, change in free energy, enthalpy, and entropy were calculated. Thermodynamic analyses indicated that the sorption of copper ions onto the calcined sludge was driven by a physical adsorption process. The prepared sludge was proven to be an excellent adsorbent material for the removal of Cu^2+ from an aqueous solution under optimum conditions.

关键词： Copper removal Adsorption Sludge Water treatment plant Operational conditions

Comparison of Artificial Neural Networks,Geographically Weighted Regression and Cokriging Methods for Predicting the Spatial Distribution of Soil Macronutrients(N,P,and K)

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Chinese Geographical Science 2017年第5期27卷 747-759页

作者： Samad EMAMGHOLIZADEH shahin SHAHSAVANI Mohamad Amin ESLAMI 1.Department of Water and Soil Engineering Shahrood University of TechnologyShahrood361999-5161Iran

Soil macronutrients(i.e. nitrogen(N), phosphorus(P), and potassium(K)) are important soils components and knowing the spatial distribution of these parameters are necessary at precision agriculture. The purpose of this study was to evaluate the feasibility of different methods such as artificial neural networks(ANN) and two geostatistical methods(geographically weighted regression(GWR) and cokriging(CK)) to estimate N, P and K contents. For this purpose, soil samples were taken from topsoil(0–30 cm) at 106 points and analyzed for their chemical and physical parameters. These data were divided into calibration(n = 84) and validation(n = 22). Chemical and physical variables including clay, p H and organic carbon(OC) were used as auxiliary soil variables to estimate the N, P and K contents. Results showed that the ANN model(with coefficient of determination R^2 = 0.922 and root mean square error RMSE = 0.0079%) was more accurate compared to the CK model(with R^2 = 0.612 and RMSE = 0.0094%), and the GWR model(with R^2 = 0.872 and RMSE = 0.0089%) to estimate the N variable. The ANN model estimated the P with the RMSE of 3.630 ppm, which was respectively 28.93% and 20.00% less than the RMSE of 4.680 ppm and 4.357 ppm from the CK and GWR models. The estimated K by CK, GWR and ANN models have the RMSE of 76.794 ppm, 75.790 ppm and 52.484 ppm. Results indicated that the performance of the CK model for estimation of macro nutrients(N, P and K) was slightly lower than the GWR model. Also, the accuracy of the ANN model was higher than CK and GWR models, which proved to be more effective and reliable methods for estimating macro nutrients.

关键词： precision agriculture soil characteristics interpolation artificial neural networks geographically weighted regression Cokriging

ROSIC: Enhancing secure and accessible robot control through open‐source instant messaging platforms

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IET Cyber-Systems and Robotics 2024年第2期6卷 35-51页

作者： Rasoul Sadeghian Shahrooz shahin Sina Sareh RCA Robotics Laboratory Royal College of ArtLondonUK

Ensuring secure communication and seamless accessibility remains a primary challenge in controlling robots *** authors propose a novel approach that leverages open-source instant messaging platforms to overcome the complexities and reduce costs associated with implementing a secure and user-centred communication system for remote robot control named Robot Control System using Instant Communication(ROSIC).By leveraging features,such as real-time messaging,group chats,end-to-end encryption and cross-platform support inherent in the majority of instant messenger platforms,we have developed middleware that establishes a secure and efficient communication system over the *** using instant messaging as the communi-cation interface between users and robots,ROSIC caters to non-technical users,making it easier for them to control *** architecture of ROSIC enables various scenarios for robot control,including one user controlling multiple robots,multiple users con-trolling one robot,multiple robots controlled by multiple users,and one user controlling one ***,ROSIC facilitates the interaction of multiple robots,enabling them to interoperate and function collaboratively as a swarm system by providing a unified communication platform that allows for seamless exchange of data and *** was specifically chosen as the instant messaging platform by the authors due to its open-source nature,robust encryption,compatibility across multiple platforms and interactive communication capabilities through channels and ***,the ROSIC is designed to communicate effectively with robot operating system(ROS)-based robots to enhance our ability to control them remotely.

关键词： encryption interactive communication remote robot control secure communication