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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

EsECC_SDN:Attack Detection and Classification Model for MANET

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Computers, Materials & Continua 2023年第3期74卷 6665-6688页

作者： veera Ankalu Vuyyuru Youseef Alotaibi Neenavath veeraiah Saleh Alghamdi Korimilli Sirisha Department of Computer Science and Engineering Koneru Lakshmaiah Education FoundationVaddeswaram522502A.PIndia Department of Computer Science College of Computers and Information SystemsUmm Al-Qura UniversityMakkah21955Saudi Arabia Department of Electronics and Communications DVR&DHS MIC Engineering CollegeKanchikacharla521180A.PIndia Department of Information Technology College of Computers and Information TechnologyTaif UniversityTaif21944Saudi Arabia Department of Electronics and Communications BVC Institute of Technology&ScienceAmalapuram533221A.PIndia

Mobile Ad Hoc Networks(MANET)is the framework for social networking with a realistic *** theMANETenvironment,based on the query,information is transmitted between the sender and *** the MANET network,the nodes within the communication range are involved in data *** the nodes that lie outside of the communication range are involved in the transmission of relay ***,due to the openness and frequent mobility of nodes,they are subjected to the vast range of security threats ***,it is necessary to develop an appropriate security mechanism for the dataMANET environment for data *** paper proposed a security framework for the MANET network signature escrow *** proposed framework uses the centralised Software Defined Network(SDN)with an ECC cryptographic *** developed security framework is stated as Escrow Elliptical Curve Cryptography SDN(EsECC_SDN)for attack detection and *** developed EsECC-SDN was adopted in two stages for attack classification and detection:(1)to perform secure data transmission between nodes SDN performs encryption and decryption of the data;and(2)to detect and classifies the attack in theMANET hyper alert based HiddenMarkovModel Transductive Deep ***,the EsECC_SDN is involved in the assignment of labels in the transmitted data in the database(DB).The escrow handles these processes,and attacks are evaluated using the hyper *** labels are assigned based on the k-medoids attack clustering through label assignment through a transductive deep learning *** proposed model uses the CICIDS dataset for attack detection and *** developed framework EsECC_SDN’s performance is compared to that of other classifiers such as AdaBoost,Regression,and Decision *** performance of the proposed EsECC_SDN exhibits∼3%improved performance compared with conventional techniques.

关键词： MANET security classifier cryptography attack escrow ECC

A combined experimental and crystal plasticity study of grain size effects in magnesium alloys

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Journal of Magnesium and Alloys 2023年第12期11卷 4445-4467页

作者： Aaditya Lakshmanan Mohsen Taheri Andani Mohammadreza Yaghoobi John Allison Amit Misra veera Sundararaghavan Department of Aerospace Engineering University of MichiganAnn ArborMI48105USA Department of Materials Science and Engineering University of MichiganAnn ArborMI48105USA Department of Mechanical Engineering University of MichiganAnn ArborMI48105USA

This work presents a method to incorporate the micro Hall-Petch equation into the crystal plasticity finite element(CPFE) framework accounting for the microstructural features to understand the coupling between grain size, texture, and loading direction in magnesium *** effect of grain size and texture is accounted for by modifying the slip resistances of individual basal and prismatic systems based on the micro Hall-Petch equation. The modification based on the micro Hall-Petch equation endows every slip system at each microstructural point with a slip system-level grain size and maximum compatibility factor, which are in turn used to modify the slip resistance. While the slip-system level grain size is a measure of the grain size, the maximum compatibility factor encodes the effect of the grain boundary on the slip system resistance modification and is computed based on the Luster-Morris factor. The model is calibrated using experimental stress-strain curves of Mg-4Al samples with three different grain sizes from which the Hall-Petch coefficients are extracted and compared with Hall-Petch coefficients predicted using original parameters from previous work. The predictability of the model is then evaluated for a Mg-4Al sample with different texture and three grain sizes subjected to loading in different directions. The calibrated parameters are then used for some parametric studies to investigate the variation of Hall-Petch slope for different degrees of simulated spread in basal texture,variation of Hall-Petch slope with loading direction relative to basal poles for a microstructure with strong basal texture, and variation of yield strength with change in grain morphology. The proposed approach to incorporate the micro Hall-Petch equation into the CPFE framework provides a foundation to quantitatively model more complicated scenarios of coupling between grain size, texture and loading direction in the plasticity of Mg alloys.

关键词： Hall-Petch Crystal plasticity Grain size Texture Magnesium alloys

粉末冶金Al-5.6Zn-2Mg合金在热压缩过程中加工硬化特性及本构模型的比较（英文）

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Journal of Central South University 2024年第2期 346-368页

作者： KATIKA Harikrishna DAMODA R.K. DAVIDSON M.J. SEETHARAM R. KASAGANI veera Venkata Nagaraju Department of Mechanical Engineering National Institute of Technology Department of Mechanical Engineering The Indian Institute of Information Technology Design and Manufacturing

在300～5000℃、应变速率为0.1～0.0001 s-1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σc(εc)以及关键特征σc(εc)、σp(εp)和σss与Z系数之间的相关性。使用了四个本... 详细信息

在300～5000℃、应变速率为0.1～0.0001 s-1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σc(εc)以及关键特征σc(εc)、σp(εp)和σss与Z系数之间的相关性。使用了四个本构模型,Arrhenius模型、改进的Johnson-Cook模型(MJC)、改进的Zerilli-Armstrong模型(MZA)和开发的人工神经网络(ANN)。结果表明,ANN型模型和Arrhenius模型的相对误差的绝对平均值最低,分别为0.486%和3.36%,MZA型模型和MJC型模型的相对误差的绝对平均值较高,分别为8.84%和3.93%。由于Arrhenius模型能够处理各种因素之间的非线性关系,因此它被认为是最合适的预测模型,但在材料性质未知或实验数据有限的情况下,MJC模型可能是一种更简单的替代方法。MZA模型不适合估计热压缩时的流变应力。此外,训练最好的神经网络模型的预测性能最好,相对误差的绝对平均值为0.486%,R值为0.99。

关键词：加工硬化速率曲线本构建模热压缩 EBSD分析流变曲线

Radiation-absorption,chemical reaction,Hall and ion slip impacts on magnetohydrodynamic free convective flow over semi-infinite moving absorbent surface

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Chinese Journal of Chemical Engineering 2021年第6期34卷 40-52页

作者： M.veera Krishna Department of Mathematics Rayalaseema UniversityKurnoolAndhra Pradesh 518007India

The investigation of radiation-absorption,chemical reaction,Hall and ion-slip impacts on unsteady MHD free convective laminar flow of an incompressible viscous,electrically conducting and heat generation/absorbing fluid enclosed with a semi-infinite porous plate within a rotating frame has been *** plate is assumed to be moving with a constant velocity in the direction of fluid movement.A uniform transverse magnetic field is applied at right angles to the porous surface,which is absorbing the fluid with a suction velocity changing with *** non-dimensional governing equations for present investigation are solved analytically making use of two term harmonic and non-harmonic *** graphical results of velocity,temperature and concentration distributions on the analytical solutions are displayed and discussed with reference to pertinent *** is found that the velocity profiles decreased with an increasing in Hartmann number,rotation parameter,the Schmidt number,heat source parameter,while it increased due to an increase in permeability parameter,radiation-absorption parameter,Hall and ion slip ***,the temperature profile is an increasing function of radiation-absorption parameter,whereas an increase in chemical reaction parameter,the Schmidt number Sc or frequency of oscillations decrease the temperature profile on ***,it is found that the concentration profile is decreased with an escalating in the Schmidt number or the chemical reaction parameter.

关键词： Chemical reaction Free convection Heat source Heat transfer Mass diffusion Radiation absorption

Sulfamic acid as a green,reusable catalyst for stepwise,tandem&one-pot solvent-free synthesis of pyrazole derivatives

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Chinese Chemical Letters 2017年第7期28卷 1571-1576页

作者： veera Swamy Konkala Pramod Kumar Dubey Department of Chemistry Jawaharlal Nehru Technological University HyderabadCollege of EngineeringKukatpally 500085India

Sulfamic acid（SA） is a bi-functional, cost-effective and reusable green catalyst for the synthesis of 4-（pyrazol-4-yl）methylenepyrazol-5（4H）-one derivatives by one-pot, three-component condensation of pyrazol-4-carbaxaldehydes, b-ketoesters and phenyl hydrazine（Route-I）. In addition to this method,another simple condensation of pyrazol-4-carbaxaldehydes with pyrazolone in the presence of SA under the solvent-free condition in good yield is reported. The merits of these protocols are mild conditions,non-aqueous workup, high yields, easy availability of the catalyst, no chromatographic separation and inexpensive solid acid catalyst. Furthermore, SA could be recycled and reused for five times without losing its catalytic activity.

关键词： Pyrazol-4-carbaxaldehydes Knoevenagel condensation Sulfamic acid Multicomponent reaction Physical grinding

Mathematical modelling on diffusion and control of COVIDe19

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Infectious Disease Modelling 2020年第1期5卷 588-597页

作者： M.veera Krishna Department of Mathematics Rayalaseema UniversityKurnoolAndhra Pradesh518007India

In this paper,we develop a mathematical model for the spread and control of the coronavirus *** outbreak of COVID-19 has led to more than one million confirmed cases as of April 3rd,*** the early spread dynamics of the infection and evaluating the effectiveness of control measures is crucial for assessing the potential for sustained transmission to occur in new *** a mathematical model of severe COVID-19 spread with four datasets from within and outside of Wuhan,China;it is estimated how spread in Wuhan varied between January and February *** is used these estimates to assess the potential for sustained human-to-human spread to occur in locations outside Wuhan if disease holders were *** is combined SEIR framework model with data on cases of COVID-19 in China and International cases that originated in Wuhan to estimate how spread had varied over time during January and February *** on these estimates,it is calculated the probability that freshly introduced cases might produce outbreaks in other ***,it is calculated approximately the median day by day basic reproduction number in Wuhan,refused from 2$45(95%CI:1.16-4.87)one week before travel restrictions were introduced on Jan 23rd,2020,to 1.05(0.42-2.40)one week *** on our estimates of,presumptuous SARS approximating disparity,it is computed that in locations with a similar spread potential to Wuhan in near the beginning of January,some time ago there are at least four independently set up cases,there is a more than fifty percent chance the infection will found within those ***-19 spreading probably refused in Wuhan during delayed January 2020,corresponding with the prologue of voyage control *** more cases arrive in international locations with similar spread potential to Wuhan,before these organize measures,it is likely many chains of spread will fail to create initially but might lead to innovative outbreaks ultimately.

关键词： COVID-19 Coronavirus Mathematical modelling Diffusion Reproduction number

Impact of geo technical factors on strata behavior in longwall panels of Godavari Valley coal field-a case study

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International Journal of Mining Science and Technology 2019年第2期29卷 335-341页

作者： veera Reddy Boothukuri Ram Madhav Bhattacharjee Durga Charan Panigrahi Gautam Benerjee Singareni Collieries Company Limited (SCCL) Indian Institute of Technology Indian School of Mines CSIR-Central Institute of Mining and Fuel Research

Understanding the cantilevers formed by thick, massive beds in the near-seam overburden above longwall panels and the associated loads and strata fracturing effects developed during caving(main and periodic weightings) are key elements for the successful implementation of longwalls. Such caving mechanisms rely on the geotechnical conditions within the panel. In India, the majority of longwall downtime and/or roof failures were caused by a lack of knowledge on overburden caveability, in particular when the main and periodic weightings will impact the face and longwall support selection to effectively mitigate such weightings. Godavari Valley Coal Fields is no exception as longwall faces were adversely affected due to the presence of thick, massive beds in the near-seam overburden at both Godavarikhani(GDK) 7 and 9 Incline mines. In contrast, overburden weightings were negotiated successfully in GDK10 A and Adriyala Longwall Project(ALP) mines by detailed geotechnical studies, the use of adequate longwall support capacities, and effective operational practices. Thirteen longwall panels with varying face width, at different depths have been extracted under massive sandstone beds of 18 m to28 m thickness at GDK 10 A and ALP mines. This study elucidates that the main roof weighting interval decreases with an increase in face width and attains a constant value with further increases in face width under the same geo-mining conditions. In addition, this study also concludes that with increases in face width, the periodic roof weighting interval decreases and shield loads increase. Similarly with increasing panel width to depth ratio, the main and periodic roof weighting intervals decrease but shield loads again increase. Lastly, the strata behaviour of the longwall face retreated along up-dip direction is demonstrated. The results of this paper improves the mechanistic understanding of the impact of face width,depth and main roof thickness on periodic weighting and associat

关键词： Longwall mining Roof weightings intervals Shield loadings Face width Cover depth

Comparison of optimal capacitor placement methods in radial distribution system with load growth and ZIP load model

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Frontiers in Energy 2013年第2期7卷 197-213页

作者： veera Venkata Satya Naryana MURTY Ashwani KUMAR Department of Electrical Engineering National Institute of TechnologyKurukshetra 136119 India

In this paper, a combined power loss sensitivity （PLS） index-based approach is proposed to determine the optimal location of the capacitors in the radial distribution system （RDS） based on the real and reactive combined loss sensitivity index, as capacitor placement not only reduces real power loss with voltage profile improvement but also reduces reactive power loss due to the reactive power compensation in the network. The results have been obtained with the existing methods of power loss index （PLI） and index vector （IV） method for comparison. Besides, the optimal placement has been obtained with the proposed method as well as existing methods and the total kVar support has been obtained. In addition, the results of net cost savings for the 10-, 34-, and 69-bus systems are obtained for comparison. Moreover, the results have been obtained for a large system of 85 buses to validate the results with combined sensitivity based approach. Further- more, the load growth factor has been considered in the study which is essential for the planning and expansion of the existing systems, whereas the impact of the realistic load model as ZIP load model has been considered for the study of all the systems.

关键词： load growth load models reactive powercompensation radial distribution system power loss index(PLI) power loss sensitivity (PLS) index vector (IV)