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Modeling the collapse of the Plasco *** I:Reconstruction of fire

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Building Simulation 2022年第4期15卷 583-596页

作者： Aatif Ali Khan Ramakanth Veera Venkata Domada Xinyan Huang Mustesin Ali Khan asif usmani Department of Building Services Engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina Research Institute for Sustainable Urban Development The Hong Kong Polytechnic UniversityKowloonHong KongChina

In recent years,fires in tall buildings have become more frequent,which costs billions of dollars each year and the loss of many human *** facade fire in the Grenfell tower made the structure uninhabitable,and the collapse of the three World Trade Center(WTC)towers is the total structural failure caused by *** such events,no well-defined methodology exists to reconstruct both fire and structural behaviors and carrys out the forensic investigation of a building *** Part I paper collects the evidence of the Plasco Building fire and generates a coherent timeline to reconstruct the fire *** vertical and horizontal fire spread of the building is reconstructed using computational fluid dynamics(CFD)fire modeling and calibrated against the evidence *** spatio-temporal temperature history from the fire modeling provides realistic fire scenarios to simulate the structural *** fire simulation results are used as boundary conditions to be transferred to a finite element analysis tool for a detailed structural analysis to determine the likely collapse mechanism of the Plasco Building in Part *** methodology presented in this paper to reconstruct the fire can also guide the structural fire safety engineers to improve the building fire-safety and life-safety strategies.

关键词： building fire safety high-rise buildings fire investigation fire modeling structure failure

油罐车火灾下钢-混凝土组合梁桥结构响应研究

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防灾减灾工程学报 2016年第3期36卷 444-452页

作者：李国强许炎彬 asif usmani 同济大学土木工程学院防灾国家重点实验室上海200092 同济大学土木工程学院上海200092 爱丁堡大学工程学院

采用数值模拟方法,研究钢-混凝土组合梁式公路桥在大型车辆火灾下的结构响应,考察桥梁形式、火灾工况及荷载比的影响。首先以规范给定的烃类火灾升温曲线及CFD模拟实际油罐车火灾所得到的升温曲线作为温度边界条件,用ABAQUS建立了8个有... 详细信息

采用数值模拟方法,研究钢-混凝土组合梁式公路桥在大型车辆火灾下的结构响应,考察桥梁形式、火灾工况及荷载比的影响。首先以规范给定的烃类火灾升温曲线及CFD模拟实际油罐车火灾所得到的升温曲线作为温度边界条件,用ABAQUS建立了8个有限元模型进行计算,得出了构件内部温度场,发现实际火灾下斜交桥受火跨最高温度低于正交桥的,但整体温度更高;实际火灾较规范火灾下结构升温更快,最高温度更高;随后以受火升温结果作为温度荷载,通过恒载升温分析,考察了共计18个案例的结构响应,发现正交桥和斜交桥在火灾下的破坏模式有较大差别,前者出现不适于继续承载的变形,同时伴随着远端支座腹板屈曲的局部破坏,而后者主要体现为远端支座腹板严重屈曲;最后提出了针对钢-混凝土组合梁桥抗火措施和设计思路的建议。

关键词：钢-混凝土组合梁桥车辆火灾参数化分析受火升温结构响应

基于OpenSees的火灾下钢结构连续性倒塌分析

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防灾减灾工程学报 2015年第1期35卷 1-5页

作者：姜健 asif usmani 李国强同济大学土木工程学院上海200092 爱丁堡大学工程与环境学院同济大学土木工程防灾国家重点实验室上海200092

主要研究了火灾下平面钢框架的连续性倒塌模式和机制。应用OpenSees软件,对某5跨8层平面钢框架结构模型进行数值分析,研究了荷载比、梁柱刚度比和火灾场景对结构倒塌模式的影响。结果表明,随着荷载比的增大,结构倒塌模式由侧向倾倒式倒... 详细信息

主要研究了火灾下平面钢框架的连续性倒塌模式和机制。应用OpenSees软件,对某5跨8层平面钢框架结构模型进行数值分析,研究了荷载比、梁柱刚度比和火灾场景对结构倒塌模式的影响。结果表明,随着荷载比的增大,结构倒塌模式由侧向倾倒式倒塌变为整体下沉式倒塌;当梁柱刚度比较小时,由于梁的悬链性效应,使结构发生偏向受火开间的侧向位移直至倒塌(弱梁机制),当梁的刚度比较大时,破坏首先发生在框架底层柱,结构呈整体下沉式倒塌(强梁机制);火灾中水平和竖向分布易分别引起结构局部和整体的倒塌。

关键词： OpenSees 钢结构抗火连续性倒塌荷载比梁柱刚度比火灾场景

Finite element analysis of non-newtonian flow:theory and software

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Quintessence anisotropic stellar models in quadratic and Born-Infeld modified teleparallel Rastall gravity

1999年

作者： Hou-Cheng Huang Zheng-Hua Li and asif S. usmani

来源：畅想之星图书光盘版（南... 评论

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Chinese Physics B 2024年第3期33卷 179-189页

作者： Allah Ditta 夏铁成 Irfan Mahmood asif Mahmood Department of Mathematics Shanghai University and Newtouch Center for Mathematics of Shanghai UniversityShanghai 200444China Centre for High Energy Physics University of the PunjabLahorePakistan College of Engineering Chemical Engineering DepartmentKing Saud University RiyadhSaudi Arabia

This study aims to discuss anisotropic solutions that are spherically symmetric in the quintessence field,which describe compact stellar objects in the modified Rastall teleparallel theory of *** achieve this goal,the Krori and Barua arrangement for spherically symmetric components of the line element is *** explore the field equations by selecting appropriate off-diagonal tetrad ***-Infeld function of torsion f(T)=β√λT+1-1 and power law form h(T)=δTn are *** Born-Infeld gravity was the first modified teleparallel gravity to discuss *** use the linear equation of state pr=ξρto separate the quintessence *** obtaining the field equations,we investigate different physical parameters that demonstrate the stability and physical acceptability of the stellar *** use observational data,such as the mass and radius of the compact star candidates PSRJ 1416-2230,Cen X-3,&4U 1820-30,to ensure the physical plausibility of our findings.

关键词： anisotropic spheres quintessence field modified Rastall teleparallel gravity equation of state(EoS) f(T)gravity

Phonon Thermal Transport at Interfaces of a Graphene/Vertically Aligned Carbon Nanotubes/Hexagonal Boron Nitride Sandwiched Heterostructure

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Chinese Physics Letters 2024年第1期41卷 57-62页

作者：李檬璘 Muhammad asif Shakoori 王瑞鹏李海鹏 School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China

Molecular dynamics simulation is used to calculate the interfacial thermal resistance of a graphene/carbon nanotubes/hexagonal boron nitride(Gr/CNTs/hBN)sandwiched heterostructure,in which vertically aligned carbon nanotube(VACNT)arrays are covalently bonded to graphene and hexagonal boron nitride *** find that the interfacial thermal resistance(ITR)of the Gr/VACNT/hBN sandwiched heterostructure is one to two orders of magnitude smaller than the ITR of a Gr/hBN van der Waals heterostructure with the same plane *** is observed that covalent bonding effectively enhances the phonon coupling between Gr and hBN layers,resulting in an increase in the overlap factor of phonon density of states between Gr and hBN,thus reducing the ITR of Gr and *** addition,the chirality,size(diameter and length),and packing density of sandwich-layer VACNTs have an important influence on the ITR of the *** the same CNT diameter and length,the ITR of the sandwiched heterostructure with armchair-shaped VACNTs is higher than that of the sandwiched heterostructure with zigzag-shaped VACNTs due to the different chemical bonding of chiral CNTs with Gr and *** the armchair-shaped CNT diameter increases or the length decreases,the ITR of the sandwiched heterostructure tends to ***,the increase in the VACNT packing density also leads to a continuous decrease in the ITR of the sandwiched heterostructure,attributed to the extremely high intrinsic thermal conductivity of CNTs and the increase of out-of-plane heat transfer *** work may be helpful for understanding the mechanism for ITR in multilayer vertical heterostructures,and provides theoretical guidance for a new strategy to regulate the interlayer thermal resistance of heterostructures by optimizing the design of sandwich layer thermal interface materials.

关键词： sandwich shaped packing

Caching Strategies in NDN Based Wireless Ad Hoc Network:A Survey

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Computers, Materials & Continua 2024年第7期80卷 61-103页

作者： Ahmed Khalid Rana asif Rehman Byung-Seo Kim Department of Computer Science FAST School of ComputingNational University of Computer and Emerging SciencesLahore54000Pakistan Department of Software and Communications Engineering Hongik UniversitySejong City30016Republic of Korea

Wireless Ad Hoc Networks consist of devices that are wirelessly *** Ad Hoc Networks(MANETs),Internet of Things(IoT),and Vehicular Ad Hoc Networks(VANETs)are the main domains of wireless ad hoc *** is used in wireless ad hoc *** is based on Transmission Control Protocol(TCP)/Internet Protocol(IP)network where clients and servers interact with each other with the help of IP in a pre-defined *** fetches data from a fixed *** redundancy,mobility,and location dependency are the main issues of the IP network *** these factors result in poor performance of wireless ad hoc *** main disadvantage of IP is that,it does not provide in-network ***,there is a need to move towards a new network that overcomes these *** Data Network(NDN)is a network that overcomes these *** is a project of Information-centric Network(ICN).NDN provides in-network caching which helps in fast response to user *** NDN in wireless ad hoc network provides many benefits such as caching,mobility,scalability,security,and *** considering the certainty,in this survey paper,we present a comprehensive survey on Caching Strategies in NDN-based Wireless *** cachingmechanism-based results are also *** the last,we also shed light on the challenges and future directions of this promising field to provide a clear understanding of what caching-related problems exist in NDN-based wireless ad hoc networks.

关键词： Content centric network Internet of Things mobile ad hoc network named data network vehicular ad hoc network

Synthesis and Thermal Characterization of Solar Salt-Based Phase Change Composites with Graphene Nanoplatelets

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Journal of Thermal Science 2024年第2期33卷 491-500页

作者： Pethurajan VIGNESHWARAN Saboor SHAIK Sivan SURESH Müslüm ARICI asif AFZAL Department of Thermal and Energy Engineering School of Mechanical Engineering(SMEC)Vellore Institute of TechnologyVelloreTamil NaduIndia Nanotechnology Research Laboratory Department of Mechanical EngineeringNational Institute of TechnologyTiruchirappalliTamil NaduIndia Mechanical Engineering Department Engineering FacultyKocaeli UniversityUmuttepe CampusKocaeli41001Turkey Department of Mechanical Engineering P.A.College of Engineering(affiliated to Visvesvaraya Technological UniversityBelagavi)Mangaluru574153India

Thermal energy storage(TES) systems use solar energy despite its irregular availability and day-night temperature *** work reports the thermal characterizations of solar salt-based phase change composites in the presence of graphene nanoplatelets(GNP).Solar salt(60:40 of NaNO_(3):KNO_(3)) possessing phase transition temperature and melting enthalpy of 221.01℃ and 134.58 kJ/kg is proposed as a phase change material(PCM) for high-temperature solar-based energy storage *** conductivity must be improved to make them suitable for widespread applications and to close the gap between the system needs where they are *** is added at weight concentrations of 0.1%,0.3%,and 0.5% with solar salt using the ball milling method to boost its thermal *** studies indicated the formation of a uniform surface of GNP on solar *** spectrum peaks identified the physical interaction between salt and *** characterization of the composites,such as thermal conductivity,DSC and TGA was carried out for the samples earlier and later 300 thermal cycles.0.5% of GNP has improved the thermal conductivity of salt by 129.67% and after thermal cycling,the enhancement reduced to 125.21% indicating that thermal cycling has a minor impact on thermal *** change temperature decreased by around 2.32% in the presence of0.5% GNP and the latent heat reduced by 4.34% after thermal *** thermograms depicted the composites initiated the weight loss at around 550℃ after which it was *** thermal cycling,the weight loss initiated at ~40℃ lower compared to pure salt,which was found to be a minor *** characterization of solar salt and GNP-based solar salt composites revealed that the composites can be used for enhanced heat transfer in high-temperature solar-based heat transfer and energy storage applications.

关键词： thermal energy storage high temperature solar salt graphene nanoplatelets thermal characterization

A Comprehensive Systematic Review: Advancements in Skin Cancer Classification and Segmentation Using the ISIC Dataset

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2131-2164页

作者： Madiha Hameed Aneela Zameer Muhammad asif Zahoor Raja Department of Computer Sciences Pakistan Institute of Engineering and Applied SciencesNilore50700Islamabad Future Technology Research Center National Yunlin University of Science and TechnologyDouliou64002TaiwanChina Directorate of IT Services University of GujratGujrat50700Pakistan

The International Skin Imaging Collaboration(ISIC)datasets are pivotal resources for researchers in machine learning for medical image analysis,especially in skin cancer *** datasets contain tens of thousands of dermoscopic photographs,each accompanied by gold-standard lesion diagnosis *** challenges associated with ISIC datasets have spurred significant advancements,with research papers reporting metrics surpassing those of human *** cancers are categorized into melanoma and non-melanoma types,with melanoma posing a greater threat due to its rapid potential for metastasis if left *** paper aims to address challenges in skin cancer detection via visual inspection and manual examination of skin lesion images,processes historically known for their *** notable advancements in machine learning and deep learning models,persistent challenges remain,largely due to the intricate nature of skin lesion *** review research on convolutional neural networks(CNNs)in skin cancer classification and segmentation,identifying issues like data duplication and augmentation *** explore the efficacy of Vision Transformers(ViTs)in overcoming these challenges within ISIC dataset *** leverage their capabilities to capture both global and local relationships within images,reducing data duplication and enhancing model ***,ViTs alleviate augmentation issues by effectively leveraging original *** a thorough examination of ViT-based methodologies,we illustrate their pivotal role in enhancing ISIC image classification and *** study offers valuable insights for researchers and practitioners looking to utilize ViTs for improved analysis of dermatological ***,this paper emphasizes the crucial role of mathematical and computational modeling processes in advancing skin cancer detection methodologies,highlighting their significance in improving algorithmic

关键词： Medical image skin cancer classification skin cancer segmentation international skin imaging collaboration convolutional neural network deep learning