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CFD simulations of a semi-transverse ventilation system in a long tunnel

Underground Space 2023年第4期11卷 153-170页

作者： Alireza Dastan Mohammad Rahiminejad Mozhgan Sabz meisam abbasi Ali Mokhtari Sasan Sadrizadeh Omid Abouali Department of Mechanical Engineering Faculty of EngineeringUniversity of IsfahanIsfahan 81746-73441Iran School of Mechanical Engineering Shiraz UniversityShiraz 71936-16548Iran Department of Mechanical Engineering University of AlbertaEdmonton T6G 2R3Canada Department of Civil and Architectural Engineering KTH UniversityStockholm 10044Sweden

In the present work,a semi-transverse ventilation system in a long tunnel with a length of 4.9 km,as a complex case study,is numer-ically studied by performing a set of three-dimensional steady incompressible computational fluid dynamics(CFD)simulations.The ven-tilation system consisted of a ceiling duct connected to two axial fans at the ending portals,and a series of jet fans in the main tunnel for supporting airflow in the desired direction.To focus on what can and cannot be achieved in commissioning tests,the ventilation system’s performance in various scenarios is numerically evaluated with two different tunnel states;empty tunnel and complete traffic congestion with 1176 stationary vehicles–which is almost impossible to evaluate during a commissioning test.By considering two hypothetical loca-tions for the extraction zone from the main tunnel(in a distance of 450 and 1000 m from one portal),it is shown that the required number of jet fans in a traffic condition drops from 57 for the first extraction location to 43(25%decrease)when the ventilation system extracts from the second zone.We show that if only the close axial fan to the extraction zone is activated,the required number of jet fans reduces by 56%and 72%for the first and second extraction locations,respectively.This finding can provide a cheaper and easier controlling scenario for emergency ventilation.

关键词： CFD Semi-transverse ventilation Tunnel Ceiling duct Traffic

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Bridging digital and electromagnetic realms for enhanced wireless communication: current space

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National Science Review 2024年第4期11卷 9-10页

作者： Qammer H.abbasi James Watt School of Engineering University of Glasgow

Digital, coding, and programmable metasurfaces have attracted widespread attention in wireless communication fields owing to their distinguished capability in manipulating electromagnetic (EM)waves [1]. Metasurfaces consist of planar subwavelength meta-atoms and are a twodimensional form of metamaterials [2].These engineered surfaces can flexibly control the properties of EM waves, such as magnitude, phase, and polarization. In particular, coding metasurfaces provide a bridge between the digital world and the physical world. Accordingly, modeling and analyzing the coding metasurfaces from the perspective of information theory has become one of the most important research focuses of the scientific community [3,4].

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Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 479-496页

作者： M.abbasi GAVARI M.R.HOMAEINEZHAD Faculty of Mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible manipulator.The manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse deformation.To accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation effects.By applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(AMM)is used to solve this nonlinear system of governing equations with appropriate shape functions.The assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the other.In addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is investigated.Despite the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the arm.Finally,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element approach.The comparison confirms the validity of the proposed dynamic model for the system.According to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(AMM) nonlinear motion analysis

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Hybrid robust fault detection and isolation of satellite reaction wheel actuators

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Journal of Control and Decision 2024年第1期11卷 117-131页

作者： H.abbasi Nozari S.J.Sadati Rostami Paolo Castaldi Silvio Simani Faculty of Electrical and Computer Engineering Babol Noshirvani University of TechnologyBabolIran Department of Electrical Electronic and Information EngineeringUniversity of BolognaCesenaItaly Department of Engineering University of FerraraFerraraItaly

In this paper,a combined robust fault detection and isolation scheme is studied for satellite system subject to actuator faults,external disturbances,and parametric uncertainties.The proposed methodology incorporates a residual generation module,including a bank of filters,into an intelligent residual evaluation module.First,residual filters are designed based on an improved nonlinear differential algebraic approach so that they are not affected by external disturbances.The residual evaluation module is developed based on the suggested series and parallel forms.Further,a new ensemble classification scheme defined as blended learning integrates heterogeneous classifiers to enhance the performance.A wide range of simulations is carried out in a high-fidelity satellite simulator subject to the constant and time-varying actuator faults in the presence of disturbances,manoeuvres,uncertainties,and noises.The obtained results demonstrate the effectiveness of the proposed robust fault detection and isolation method compared to the traditional nonlinear differential algebraic approach.

关键词： Robust fault detection and isolation reaction wheels blended learning series and parallel fault detection and isolation forms satellite attitude control system

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The Lambert-G Family:Properties,Inference,and Applications

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 513-536页

作者： Jamal N.Al abbasi Ahmed Z.Afify Badr Alnssyan Mustafa S.Shama Accounting Department Ashur UniversityBaghdad10011Iraq Department of Statistics Mathematics and InsuranceBenha UniversityBenha13511Egypt Department of Management Information Systems and Production Management College of Business and EconomicsQassim UniversityBuraydah51452Saudi Arabia Department of Basic Sciences Common First Year(CFY)King Saud UniversityRiyadh11362Saudi Arabia Department of Mathematics and Statistics Osim Higher Institute of Administrative ScienceOsim12961Egypt

This study proposes a new flexible family of distributions called the Lambert-G family.The Lambert family is very flexible and exhibits desirable properties.Its three-parameter special sub-models provide all significantmonotonic and non-monotonic failure rates.A special sub-model of the Lambert family called the Lambert-Lomax(LL)distribution is investigated.General expressions for the LL statistical properties are established.Characterizations of the LL distribution are addressed mathematically based on its hazard function.The estimation of the LL parameters is discussed using six estimation methods.The performance of this estimation method is explored through simulation experiments.The usefulness and flexibility of the LL distribution are demonstrated empirically using two real-life data sets.The LL model better fits the exponentiated Lomax,inverse power Lomax,Lomax-Rayleigh,power Lomax,and Lomax distributions.

关键词： Lambert function Lomax distribution maximum likelihood hazard function statistical model simulation

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Global systematic review and meta-analysis of knowledge, attitudes, and practices towards dengue fever among the general population

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Asian Pacific Journal of Tropical Medicine 2024年第5期17卷 191-207,I0001-I0003页

作者： Abdolreza Sotoodeh Jahromi Mohammad Jokar Arman Abdous Nader Sharifi Tahere abbasi Vahid Rahmanian Zoonoses Research Center Jahrom University of Medical SciencesJahromIran Faculty of Veterinary Medicine Karaj BranchIslamic Azad UniversityKarajIran Department of Public Health Khomein University of Medical SciencesKhomeinIran Research Center for Social Determinants of Health Jahrom University of Medical SciencesJahromIran Department of Public Health Torbat Jam Faculty of Medical SciencesTorbat JamIran

Objective:To determine the global level of knowledge,attitudes,and practices towards dengue fever among the general population.Methods:To complete this systematic review and meta-analysis,a thorough search for pertinent English-language literature was undertaken during the study's extension until October 2023.The search used Google Scholar,Scopus,PubMed/MEDLINE,Science Direct,Web of Science,EMBASE,Springer,and ProQuest.A quality assessment checklist developed using a modified Newcastle-Ottawa Scale for the cross-sectional study was used to evaluate the risk of bias in the included papers.Inverse variance and Cochran Q statistics were employed in the STATA software version 14 to assess study heterogeneity.When there was heterogeneity,the Dersimonian and Liard random-effects models were used.Results:59 Studies totaling 87353 participants were included in this meta-analysis.These investigations included 86278 participants in 55 studies on knowledge,20196 in 33 studies on attitudes,and 74881 in 29 studies on practices.The pooled estimates for sufficient knowledge,positive attitudes,and dengue fever preventive behaviors among the general population were determined as 40.1%(95%CI 33.8%-46.5%),46.8%(95%CI 35.8%-58.9%),and 38.3%(95%CI 28.4%-48.2%),respectively.Europe exhibits the highest knowledge level at 63.5%,and Africa shows the lowest at 20.3%.Positive attitudes are most prevalent in the Eastern Mediterranean(54.1%)and Southeast Asia(53.6%),contrasting sharply with the Americas,where attitudes are notably lower at 9.05%.Regarding preventive behaviors,the Americas demonstrate a prevalence of 12.1%,Southeast Asia at 28.1%,Western Pacific at 49.6%,Eastern Mediterranean at 44.8%,and Africa at 47.4%.Conclusions:Regional disparities about the knowledge,attitude and preventive bahaviors are evident with Europe exhibiting the highest knowledge level while Africa has the lowest.These findings emphasize the importance of targeted public health interventions tailored to regional contexts,highlighting the need for region-specif

关键词： Break-bone fever Knowledge Attitudes Practices

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Are gender inclusiveness and rural transformation interlinked?The case of Bangladesh

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Journal of Integrative Agriculture 2024年第6期23卷 2112-2126页

作者： Maria Fay Rola-Rubzen Mohammad Jahangir Alam Jon Marx Sarmiento Ismat Ara Begum Al Amin Al abbasi Subrata Saha UWA School of Agriculture and Environment The University of Western AustraliaPerth 6009Australia Department of Agribusiness and Marketing Bangladesh Agricultural UniversityMymensingh-2202Bangladesh Department of Agricultural Economics Bangladesh Agricultural UniversityMymensingh-2202Bangladesh

Gender inclusiveness is important in the rural transformation process of Bangladesh as rural women play key roles in both agricultural and non-agricultural sectors.Gender inclusiveness also leads to gender equity.We empirically evaluate relationships between rural transformation and gender inclusiveness in Bangladesh.We consider three rural transformation indicators:high-value commodities’share in agricultural output values,non-farm employment’s share in rural labor employment,and non-agricultural GDP’s share in total GDP.Indicators capturing gender inclusiveness include the per capita rural income of males and females,ratio of investments into gender programs,female access to education,access to healthcare,employment participation,land ownership,and asset ownership.We test the effect of the difference in per capita rural income of males and females and the ratio of their incomes and check for the robustness of the gender variables across different model specifications.Analyzing 128 district-level observations from 32 districts of Bangladesh across four time periods(2000,2005,2010 and 2016),we use both ordinary least squares and fixed effects panel regression models.We find that female land and asset ownership and access to education and healthcare are robust determinants of various stages of rural transformation.Thus,our results suggest that improving women’s ownership of land and assets and investing in women’s education and healthcare will likely contribute to a more inclusive rural transformation.

关键词： rural transformation Bangladesh gender inclusiveness investments on women

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Ti6Al4V合金表面渗钽层的制备及力学性能

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太原理工大学学报 2024年

作者：付光远林乃明李小凯 meisam Nouri 曾群锋 Dongyang Li 吴玉程太原理工大学材料科学与工程学院 Department of Materials Engineering Bu-Ali Sina University 西安交通大学机械工程学院 Department of Chemical and Materials Engineering University of Alberta 合肥工业大学有色金属与加工技术国家地方联合工程研究中心

为提高Ti6Al4V（TC4）合金的表面性能，借助双层辉光等离子表面合金化技术在其表面制备渗钽层，结合Taguchi实验设计研究了工艺参数对渗钽层表面硬度的影响。借助光学显微镜，X射线衍射仪，扫描电子显微镜及能量谱仪分析渗钽层的特征。... 详细信息

为提高Ti6Al4V（TC4）合金的表面性能，借助双层辉光等离子表面合金化技术在其表面制备渗钽层，结合Taguchi实验设计研究了工艺参数对渗钽层表面硬度的影响。借助光学显微镜，X射线衍射仪，扫描电子显微镜及能量谱仪分析渗钽层的特征。使用显微硬度计和纳米压入仪对比研究TC4基体和渗钽层的力学性能。结果表明：得到优化的工艺参数组合：温度750 ℃，源阴极压差350 V，保温时间2 h。优化工艺参数的渗钽层连续、均匀、致密，主要由α-Ta和金属间化合物相构成。渗钽层表面硬度比TC4基体提高了约3.2倍，其H/E和H3/E2值分别是TC4基体的2.1倍和15.0倍。双辉等离子表面合金化渗钽处理显著提高了TC4合金的抵抗局部塑性变形能力。

关键词：钛合金双辉等离子表面合金化钽力学性能

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DIRECT IMPLEMENTATION OF TIKHONOV REGULARIZATION FOR THE FIRST KIND INTEGRAL EQUATION

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Journal of Computational Mathematics 2022年第3期40卷 335-353页

作者： meisam Jozi Saeed Karimi Department of Mathematics Persian Gulf UniversityBushehrIran

A common way to handle the Tikhonov regularization method for the first kind Fredholm integral equations,is first to discretize and then to work with the final linear system.This unavoidably inflicts discretization errors which may lead to disastrous results,especially when a quadrature rule is used.We propose to regularize directly the integral equation resulting in a continuous Tikhonov problem.The Tikhonov problem is reduced to a simple least squares problem by applying the Golub-Kahan bidiagonalization(GKB)directly to the integral operator.The regularization parameter and the iteration index are determined by the discrepancy principle approach.Moreover,we study the discrete version of the proposed method resulted from numerical evaluating the needed integrals.Focusing on the nodal values of the solution results in a weighted version of GKB-Tikhonov method for linear systems arisen from the Nystr¨om discretization.Finally,we use numerical experiments on a few test problems to illustrate the performance of our algorithms.

关键词： First kind integral equation Golub-Kahan bidiagonalization Tikhonov regularization Quadrature Discretization

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Conversion of CO into CO_(2) by high active and stable PdNi nanoparticles supported on a metal-organic framework

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Frontiers of Chemical Science and Engineering 2022年第7期16卷 1139-1148页

作者： Fateme abbasi Javad Karimi-Sabet Zeinab abbasi Cyrus Ghotbi Department of Petroleum and Chemical Engineering Sharif University of TechnologyTehranIran Nuclear Fuel Cycle Research School Nuclear Science and Technology Research InstituteTehranIran

The solubility of Pd(NO_(3))_(2) in water is moderate whereas it is completely soluble in diluted HNO_(3) solution. Pd/MIL-101(Cr) and Pd/MIL-101-NH_(2)(Cr) were synthesized by aqueous solution of Pd(NO_(3))_(2) and Pd(NO_(3))_(2) solution in dilute HNO_(3) and used for CO oxidation reaction. The catalysts synthesized with Pd(NO_(3))_(2) solution in dilute HNO_(3) showed lower activity. The aqueous solution of Pd(NO_(3))_(2) was used for synthesis of mono-metal Ni, Pd and bimetallic PdNi nanoparticles with various molar ratios supported on MOF. Pd_(70)Ni_(30)/MIL-101(Cr) catalyst showed higher activity than monometallic counterparts and Pd+ Ni physical mixture due to the strong synergistic effect of PdNi nanoparticles, high distribution of PdNi nanoparticles, and lower dissociation and desorption barriers. Comparison of the catalysts synthesized by MIL-101(Cr) and MIL-101-NH_(2)(Cr) as the supports of metals showed that Pd/MIL-101-NH_(2)(Cr) outperforms Pd/MIL-101-(Cr) because of the higher electron density of Pd resulting from the electron donor ability of the NH_(2) functional group. However, the same activities were observed for Pd_(70)Ni_(30)/MIL-101(Cr) and Pd_(70)Ni_(30)/MIL-101-NH_(2)(Cr), which is due to a less uniform distribution of Pd nanoparticles in Pd_(70)Ni_(30)/MIL-101-NH_(2)(Cr) originated from amorphization of MIL-101-NH_(2)(Cr) structure during the reduction process. In contrast, Pd_(70)Ni_(30)/MIL-101(Cr) revealed the stable structure and activity during reduction and CO oxidation for a long time.

关键词： CO oxidation heterogeneous catalysis metal-organic framework NH_(2)functional group PdNi

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