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| 1 | Selection of regression models for predicting strength and deformability properties of rocks using GA显示文摘Recently,many regression models have been presented for prediction of mechanical parameters of rocks regarding to rock index properties.Although statistical analysis is a common method for developing regression models,but still selection of suitable transformation of the independent variables in a regression model is diffcult.In this paper,a genetic algorithm(GA)has been employed as a heuristic search method for selection of best transformation of the independent variables(some index properties of rocks)in regression models for prediction of uniaxial compressive strength(UCS)and modulus of elasticity(E).Firstly,multiple linear regression(MLR)analysis was performed on a data set to establish predictive models.Then,two GA models were developed in which root mean squared error(RMSE)was defned as ftness function.Results have shown that GA models are more precise than MLR models and are able to explain the relation between the intrinsic strength/elasticity properties and index properties of rocks by simple formulation and accepted accuracy. | Manouchehrian Amin Sharifzadeh Mostafa Hamidzadeh Moghadam Rasoul Nouri Tohid | 2013 | International Journal of Mining Science and Technology2013，23，4： | 9 |
| 2 | Correlation between process parameters,grain size and hardness of friction-stir-welded Cu-Zn alloys显示文摘In this study, the effects of tool rotational speed, tool traverse speed, and Zn content on the grain size and hardness of the friction-stir-welded(FSWed) Cu-Zn alloy joints were investigated. The microstructures of the joints were examined using optical microscope(OM) and scanning transmission electron microscope(STEM).Vickers hardness test was conducted to evaluate the hardness of the joints. In addition, the relationships between the process parameters, grain size, and hardness of the joints were established. The results show that the developed relationships predict the grain size and hardness of the joints accurately. The Zn content of the alloys is the most effective parameter on the grain size and hardness, where the tool traverse speed has the minimum effect. The relationship between the hardness and grain size of the joints has a deviation from the Hall-Petch equation due to formation of high dislocation density inside the grains. At higher Zn amounts, the dislocation tangles with high density form instead of dislocation cells, and hence, lower conformity with the Hall-Petch relationship is observed. | Akbar Heidarzadeh Tohid Saeid | 2018 | Rare Metals2018，37，5： | 6 |
| 3 | Numerical study of the semi-circular bend dynamic fracture toughness test using discrete element models显示文摘The semi-circular bend(SCB) dynamic fracture toughness test is simulated using discrete element models. The influence of the frictional boundary condition, constitutive law and specimen thickness on the test measurements is investigated. It is found that friction between loading plates and the rock specimen affects the test results. Therefore, friction must be carefully considered to obtain accurate measurements. The simulation results also show that in contrast to the 2D model in which a rate-dependent cohesive law must be introduced, 3D models with a rate-independent law can produce good results. Furthermore, the study suggests that test measurements are seriously affected by specimen thickness; thus, full 3D modeling is required for simulation of the SCB test. | ZHAO GaoFeng KAZERANI Tohid MAN Ke GAO Mz ZHAO Jian | 2015 | Science China(Technological Sciences)2015，58，9： | 4 |
| 4 | Gas–solid interface charge characterisation techniques for HVDC GIS/GIL insulators显示文摘Surface charge accumulation on the spacers is one of the key issues restraining the development of HVDC GIS/GIL.The precise measurement of surface charge properties provides the basis for further study of the surface charge transport mechanism as well as the charge-induced flashover mechanism under DC voltage.In this study,the authors discuss their perspective on the current status,development needs and potential developing orientation of surface charge characterisation techniques.Different surface potential measurement methods and charge inversion algorithms are reviewed regarding the previous studies and future research needs.Drawbacks and outlooks of surface charge measurement techniques are also discussed with the background of laboratory experiment results and on-site measurements.It is hopefully that this study can serve as a useful guide reference for researchers within the same research field.More importantly,it is authors’hope that this study can inspire some novel ideas for readers into developing of more accurate and scientific interface charge characterisation techniques. | Lei Zhang Chuanjie Lin Chuanyang Li Simone Vincenzo Suraci Geng Chen Uwe Riechert Tohid Shahsavarian Masayuki Hikita Youping Tu Zhousheng Zhang Davide Fabiani Jinliang He | 2020 | High Voltage2020，5，2： | 4 |
| 5 | Temperature-dependent partial discharge characteristics of high temperature materials at DC voltage for hybrid propulsion systems显示文摘The safe and reliable operation of insulation material used in key high voltage compo-nents under extreme environmental conditions represents the major concerns for man-ufacturers and operators of More Electric Aircrafts(MEA).Surface discharge occurring in high current carrying components in DC power system diminishes the insulation material’s performance and life,especially at high-temperature conditions.Here,the surface discharge behaviour of two commonly used high-temperature insulation materials,ethylene-tetrafluoroethylene(ETFE)and polyetheretherketone(PEEK)is studied at different temperatures under ramp and DC voltages.Extracted partial discharge(PD)features are presented and the impact of voltage polarity on surface discharge propagation is discussed.Our studies reveal that,while both materials exhibit non-linear PD behaviour with respect to their electrical conductivity,ETFE generally shows PDs with higher in-tensity at high temperature above 100°C with a higher possibility of surface discharge due to its lower permittivity.Overall,the PD mechanism in high-temperature,DC voltage applications is explored,and a basis for the selection of high-temperature PD suppressing materials is developed. | Tohid Shahsavarian Xin Wu Charles Lents Di Zhang Chuanyang Li Yang Cao | 2021 | High Voltage2021，6，4： | 2 |
| 6 | Feasibility of C_(3)F_(7)CN/CO_(2)gas mixtures in high-voltage DC GIL:a review on recent advances显示文摘With the rise of renewable energy resources,especially offshore wind power plant,the DC transmission concept has attracted more and more attention.The selection of eco-friendly insulating gas,as most critical insulating part of gas-insulated equipment is top priority for developing highly reliable system.Moreover,it is acknowledged that eco-friendly C_(3)F_(7)CN/CO_(2) gas mixtures have become a potential alternative to SF_(6) gas due to its excellent performance.This study reviews the basic physical properties of C_(3)F_(7)CN gas/gas mixtures and insulation properties including the gas gap breakdown and surface flashover performance at DC,as well as lightning impulse voltage.Investigation about the gas stability is presented,including the compatibility of gas with solid materials in gas-insulated transmission line(GIL),and the decomposition characteristics under long-term electrical and thermal stresses.The important progress on the charge accumulation characteristics of gas-solid interface in the novel gas environment under DC voltage stress is analysed.Finally,the key issues that need to be paid attention to and further followed through regarding the application of this novel gas in GIL are summarised and put forward.This study hopefully can provide a complete reference for the development of eco-friendly DC gas insulation equipment with C_(3)F_(7)CN/CO_(2) gas mixtures. | Youping Tu Geng Chen Cong Wang Yuming Shao Yujing Tong Chuanyang Li Guoming Ma Tohid Shahsavarian | 2020 | High Voltage2020，5，4： | 2 |
| 7 | Significant enhancement in the electrical conductance properties of ethylene propylene diene monomer using the nano‐SiO_(2) particles显示文摘To study the effect of nano‐silica particles on the conductivity characteristics of ethylene propylene diene monomer(EPDM)insulation,EPDM nanocomposites with different mass fractions of nano silica were prepared via the melt‐blending method.Scanning electron microscopy was used to analyze the dispersion of nanoparticles in EPDM.Based on the Fourier‐transform infrared spectrum,the bonding properties between the nanoparticles and EPDM were analyzed.The steady‐state current at 30-100°C and 1-20 kV/mm was measured.Moreover,the conductivity characteristic was analyzed.The experimental results show that as the content of nano‐silica increases,the electrical conductivity of EPDM nanocomposite as well as the threshold field strength gradually decreases.Samples with a small number of nanoparticles will increase the activation energy of the carrier conductivity,and the interface region effect introduced by nanoparticles will reduce the carrier mobility and concentration,resulting in a lower conductivity.Comparing the calculated value of the dielectric constant with the measured value can conclude that the high‐field conductance process is a combination of the electrode effect and the body effect,which in this case,Schottky effect dominates. | Chunyu Xu Ruixue Zhao Chuanyang Li Yuanyuan Li Guodong Zhang Tohid Shahsavarian Mengqiang Yuan Zhipeng Lei | 2021 | High Voltage2021，6，3： | 2 |
| 8 | 基于ANSYS的10 MW风力机叶片弯扭耦合特性研究显示文摘为分析弯扭耦合效应对大型风力机叶片气动性能的影响。文中使用三维有限元软件ANSYS建立了10 MW复合材料风力机叶片模型,通过改变梁帽位置单轴向布的铺层角度在叶片中引入弯扭耦合效应,改变铺层角度和耦合区域,分析叶片在气动载荷作用下的变形情况。结果表明:叶片在弯扭耦合作用下产生弯曲变形的同时会发生扭转变形,沿叶片展向变形量增加;该叶片可达到的最大扭转变形量为6度;弯扭耦合系数随着铺层角度的增大而减小。 | 王子文 杨涛 Vasilis Riziotis Giannis Seferain Tohid Bagherpour | 2019 | 应用能源技术2019，0，6： | 2 |
| 9 | Solving unit commitment problem using a novel version of harmony search algorithm显示文摘在这上下文,新奇结构为改进和谐搜索(HS ) 算法解决联合起来的评价(UC ) 被建议问题。HS 算法由即席创作为定义客观功能获得了最佳的答案,更新并且检查操作符。在建议改进自我适应的 HS (SGHS ) 算法,二个重要控制参数被适应从简单 HS 算法到达更好的答案。这研究的客观功能由操作,启动和关闭费用组成了。证实有效性, SGHS 算法与 10, 20, 40 和 60 在系统上被测试产生单位,和获得的结果与简单 HS 算法和另外的相关工作的那些相比。 | Roozbeh MORSALI Tohid JAFARI Amirhossein GHODS Mohammad KARIMI | 2014 | Frontiers in Energy2014，8，3： | 1 |
| 10 | Extending the use of peripheral intravenous catheter and administration sets from 72hours to 96hours显示文摘 | Tohid HB Sim NK Lin LM | 2005 | Singapore Nursing Journal2005，32，2： | 1 |
| 11 | Magnetic Molecularly Imprinted Nanoparticles Based on Grafting Polymerization for SelectiveDetection of 4-Nitrophenol in Aqueous Samples显示文摘 | Ali M Tohid B K Ali J | 2013 | J Chromatogr A2013，1283，： | 1 |
| 12 | Efficacy of mannanoligosaccharides and humate on imm-une response to Avian Influenza(H9)disease vaccination in broiler chickens显示文摘 | Tohid T Hasan G Alireza T | 2010 | Vet Res Communicat2010，34，8： | 1 |
| 13 | Magnetic molecularly imprinted nanoparticles based on grafting polymerization for selective detection of 4-nitrophenol in aqueous samples显示文摘 | Ali Mehdinia Tohid Baradaran Kayyal Ali Jabbari Mohammad Ovais Aziz-Zanjani Ehsan Ziaei | 2013 | Journal of Chromatography A2013，，： | 1 |
| 14 | Extending the use of peripheral intravenous catheter and administration sets from 72hours to 96hours 显示文摘 | Tohid HB Sim NK Lin LM | 2005 | Singapore Nursing Journal2005，32，2： | 1 |
| 15 | Using an Inhibitor to Prevent Plasticizer Migration from Polyurethane Matrix to EPDM Based Substrate显示文摘The loss of adhesion between the propellant and insulator is one of the most important problems in solid propellant motors due to migration of plasticizer to interface of propellant and insulator. In this work, the polyurethane (PU) binder containing DOP plasticizer was used as a polymeric matrix and β-cyclodextrin (β-CD) was applied as inhibitor agent to prevent plasticizer migration from the PU matrix into the ethylene propylene diene monomer (EPDM) substrate. To increase the compatibility of β-CD and PU matrix, a derivative of β-CD has been synthesized using toluene diisocyanate (β-CD-TDI). The synthesized derivative was characterized by MALDI-MS and FTIR-ATR analyses. FTIR-ATR results confirmed the formation of bonding between β-CD and the polymeric network while the MALDIMS results showed that the synthesized derivative contained two β-CD and 7 TDI molecules bonded to β-CD. Investigation of the mechanical properties of PU modified by β-CD-TDI showed a decrease in tensile strength and an increase in elongation at break with increasing β-CD-TDI content. DMTA results showed a decrement in crosslinking density by increasing the β-CD-TDI content. Also, to investigate plasticizer migration, extraction of the DOP plasticizer from samples was performed using dichloromethane solvent and its concentration was measured by gas chromatography. The results of migration evaluation after four months showed that using β-CD as an inhibitor agent in the PU binder could prevent the migration of plasticizer to EPDM substrate. | Hadi Rezaei-Vahidian Tohid Farajpour Mahdi Abdollahi | 2019 | Chinese Journal of Polymer Science2019，37，7： | 1 |
| 16 | Understanding DC Partial Discharge:Recent Progress,Challenges,and Outlooks显示文摘As a non-destructive local gas breakdown phenomenon within a surface or bulk cavity surrounded by insulation,partial discharge(PD)contains important information which can be used to evaluate and diagnose electrical insulation systems.In this paper,distinctive characteristics of PD for DC versus AC are reviewed.A summary of experimental studies on DC PD in different insulation coordinations is presented,including PD in gaseous insulating media,PD in solid insulating media and PD in liquid insulating media.Conclusions and some thoughts based on existing studies are provided,and challenges and suggestions for future studies are given.This paper can serve as a guide reference for readers to learn the background and state-of-the-art of DC PD studies.More importantly,it is hopeful that this study can inspire novel ideas for further advancing fundamental research of DC PD mechanisms and PD mitigation methods. | Chuanyang Li Tohid Shahsavarian Mohamadreza Arab Baferani Kerry Davis Yang Cao Di Zhang | 2022 | CSEE Journal of Power and Energy Systems2022，8，3： | 1 |
| 17 | Extending the use of peripheral intravenous catheter and administration sets from 72hours to 96 hours 显示文摘 | Tohid HB Sim NK Lin LM | 2005 | Singapore Nursing Journal2005，32，2： | 1 |
| 18 | Efficacy of Mannanoligosaccharides and Humate on Immune Response to Avian In- fluenza (H9) Disease Vaccination in Broiler Chickens显示文摘 | TOHID T HASAN G ALIREZA T | 2010 | Veterinary Research Communications2010，34，： | 1 |
| 19 | Effects of Welding and rotational speeds on the Microstructure and Hardness of Friction Stir Welded Single-Phase Brass显示文摘This study focuses on the effects of rotational and welding speeds on the microstructure and hardness of joints in friction stir welded single-phase brass. Welds were achieved under low heat input conditions at rotational and welding speeds of 400–800 r/min and 100–300 mm/min, respectively. In order to characterize the obtained welds, optical microscopy and Vickers hardness measurements were taken on the weld cross sections. According to the obtained results,increasing the welding speed and/or decreasing the rotational speed caused the grain size of the stir zone to decrease and,hence, improved the average hardness of this region. These results are discussed with respect to the interplay between the welding parameters and the peak temperature in the weld thermal cycle. | Sajjad Emami Tohid Saeid | 2015 | Acta Metallurgica Sinica(English Letters)2015，28，6： | 1 |
| 20 | Altered endometrial expression of endothelial nitric oxide synthase in women with unexplained recur- rent miscarriage and infertility 显示文摘 | Tohid N Marefat G N Reza G | 2012 | Reprod Bio Med2012，25，4： | 1 |
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