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Defence Technology（防务技术） 2019年第1期15卷 72-82页

作者： Ankush Choudhary manoj kumar Deepak Rajendra Unune Department of Mechanical-Mechatronics Engineering The LNM Institute of Information Technology

Submerged arc welding(SAW), owing to its high deposition rate and high welding quality, is widely used in the fabrication of pressure vessel, marine vessel, pipelines and offshore structures. However, selection of an optimum combination of welding parameters is critical in achieving high weld quality and productivity. In this work, initially, the SAW experiments were performed using fractional factorial design to analyze the effect of direct and indirect input parameters, namely, welding voltage, wire feed rate,welding speed, nozzle to plate distance, flux condition, and plate thickness on weld bead geometrical responses viz. bead width, reinforcement, and penetration. The bead on plate technique was used to deposit weld metal on AISI 1023 steel plates. The effect of SAW input parameters on response variables were analyzed using main and interaction effects. The linear regression was used to develop the mathematical models for the response variable. Then, the multi-objective optimization of input parameters was carried out using desirability approach, genetic algorithm and Jaya algorithm. The Jaya algorithm offered better optimization results as compared to desirability approach, genetic algorithm.

关键词： Submerged arc welding Optimization Regression Genetic algorithm Jaya algorithm

An analytical solution of multi-dimensional space fractional diffusion equations with variable coefficients

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第1期12卷 229-255页

作者： Pratibha Verma manoj kumar Department of Mathematics Motilal Nehru National Institute of Technology Allahabad Prayagraj 211004 Uttar PradeshIndia

In this paper,we have considered the multi-dimensional space fractional diffusion equations with variable *** fractional operators(derivative/integral)are used based on the Caputo *** study provides an analytical approach to determine the analytical solution of the considered problems with the help of the two-step Adomian decomposition method(TSADM).Moreover,new results have been obtained for the existence and uniqueness of a solution by using the Banach contraction principle and a fixed point *** have extended the dimension of the space fractional diffusion equations with variable coefficients into ***,the generalized problems with two different types of the forcing term have been included demonstrating the applicability and high efficiency of the TSADM in comparison to other existing numerical *** diffusion coefficients do not require to satisfy any certain conditions/restrictions for using the *** are no restrictions imposed on the problems for diffusion coefficients,and a similar procedures of the TSADM has followed to the obtained analytical solution for the multi-dimensional space fractional diffusion equations with variable coefficients.

关键词： Caputo fractional operators space fractional diffusion equations Riesz derivative two-step Adomian decomposition method fixed point theorem

Numerical solution for singular differential equations using Haar wavelet

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第5期11卷 31-45页

作者： Shitesh Shukla manoj kumar Department of Mathematics Motilal Nehru National Institute of Technology Allahabad Prayagraj-211004(U.P) India

The aim of this paper is to obtain the numerical solution of singular ordinary differential equations using the Haar-wavelet *** proposed method is mathematically simple and provides highly accurate *** this method,we derive the Haar operational matrix using Haar *** operational matrix is a basic tool and applied in system analysis to evaluate the numerical solution of differential *** convergence of the proposed method is discussed through its error *** illustrate the efficiency of this method,solutions of four singular differential equations are obtained.

关键词： Haar operational matrix singularity quasilinearization technique piecewise continuous function

Propagation delay and power dissipation for different aspect ratio of single-walled carbon nanotube bundled TSV

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Journal of Semiconductors 2015年第6期36卷 99-104页

作者： Tanu Goyal manoj kumar Majumder Brajesh kumar Kaushik Department of ECE IEC College of Engineering and Technology Department of E&CE Indian Institute of Technology Roorkee

Through-silicon vias （TSVs） have provided an attractive solution for three-dimensional （3D） integrated devices and circuit technologies with reduced parasitic losses and power dissipation, higher input-output （I/O） den- sity and improved system performance. This paper investigates the propagation delay and average power dissipation of single-walled carbon nanotube bundled TSVs having different via radius and height. Depending on the physical configuration, a comprehensive and accurate analytical model of CNT bundled TSV is employed to represent the via （vertical interconnect access） line of a driver-TSV-load （DTL） system. The via radius and height are used to estimate the bundle aspect ratio （AR） and the cross-sectional area. For a fixed via height, the delay and the power dissipation are reduced up to 96.2% using a SWCNT bundled TSV with AR = 300 ： 1 in comparison to AR = 6：1.

关键词： carbon nanotube through-silicon vias equivalent RLC circuit model propagation delay power-delay product area-delay product

Chemical and physical studies of metallic alloy-based old Indian coins with LIBS coupled with multivariate analysis

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Plasma Science and Technology 2023年第9期25卷 91-103页

作者： Vikas GUPTA Abhishekh kumar RAI Tejmani kumar Rajendhar JUNJURI G manoj kumar A K RAI Laser Spectroscopy Research Laboratory Department of PhysicsUniversity of AllahabadPrayagraj 211002India Department of Earth and Planetary Sciences University of AllahabadPrayagraj 211002India Advanced Centre of Research in High Energy Materials University of HyderabadHyderabad 500046 India Leibniz Institute of Photonic Technology Jena D-07745Germany

The present work aims to demonstrate the capabilities of Laser-induced Breakdown Spectroscopy(LIBS)coupled with a multivariate technique for rapid quantification and classification of old Indian coins made of various *** old Indian coins in different years of circulation,(1922–1986)were selected for the *** concentrations were determined by Calibration free LIBS(CF-LIBS)*** concentration of cuprum(Cu)is negligible,and aluminum(Al)is maximum in the first five coins,and vice-versa in the remaining eight *** different multivariate methods,Principal Component Analysis(PCA)and Soft Independent Modelling of Class Analogy(SIMCA)have been used to classify and identify the *** classified all thirteen samples into four main alloy *** discernment of unknown samples to their probable class membership of alloy was performed using *** surface hardness(Brinell hardness number)is linearly correlated with the plasma temperature and LIBS intensity *** sample surface of the first and fifth coin belongs to Al-alloy,having the least surface hardness,and it became harder for Cu–Ni alloy,Ni-brass alloy,and bronze *** hardness of the surface is more for bronze sample *** is also observed that the plasma temperature increases monotonically with the Brinell hardness *** analysis provides valuable information on fabrication methodology and explains large diversification in the elementary composition of old coins.

关键词： LIBS metallic alloy stoichiometric ablation PCA SIMCA old indian coins surface hardness

Multilayer perceptron and Chebyshev polynomials-based functional link artificial neural network for solving differential equations

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第2期12卷 104-119页

作者： Shagun Panghal manoj kumar Department of Mathematics Motilal Nehru National Institute of Technology Allahabad 211004 India

This paper discusses the issues of computational efforts and the accuracy of solutions of differential equations using multilayer perceptron and Chebyshev polynomials-based functional link artificial neural *** ordinary and partial differential equations have been solved by both these techniques and pros and cons of both these type of feedforward networks have been discussed in *** from that,various factors that affect the accuracy of the solution have also been analyzed.

关键词： Multilayer perceptron optimization functional link neural network trial solution Chebyshev polynomials

Positive solutions and stability of fuzzy Atangana–Baleanu variable fractional differential equation model for a novel coronavirus (COVID-19)

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第6期12卷 205-229页

作者： Pratibha Verma manoj kumar Department of Mathematics Motilal Nehru National Institute of Technology Allahabad Prayagraj 211004 Uttar PradeshIndia

This work provides a new fuzzy variable fractional COVID-19 model and uses a variablefractional operator, namely, the fuzzy variable Atangana–Baleanu fractional derivativesin the Caputo sense. Next, we explore the proposed fuzzy variable fractional COVID-19 model using the fixed point theory approach and determine the solution’s existenceand uniqueness conditions. We choose an appropriate mapping and with the help ofthe upper/lower solutions method. We prove the existence of a positive solution for theproposed fuzzy variable fractional COVID-19 model and also obtain the result on theexistence of a unique positive solution. Moreover, we discuss the generalized Hyers–Ulam stability and generalized Hyers–Ulam–Rassias stability. Further, we investigate theresults on maximum and minimum solutions for the fuzzy variable fractional COVID-19model.

关键词： Novel coronavirus(COVID-19) variable Atangana–Baleanu fractional derivative Mittag–Leffler kernel existence and uniqueness fixed point theorems Hyers–Ulam stability

Tribology of WC reinforced SiC ceramics: Influence of counterbody

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Friction 2019年第2期7卷 129-142页

作者： Sandan kumar SHARMA B.Venkata manoj kumar Young-Wook KIM Department of Metallurgical and Materials Engineering Indian Institute of Technology (IIT) Roorkee TriboCeramics Laboratory Department of Materials Science and Engineeringthe University of Seoul

Hot pressed silicon carbide(SiC) composites prepared with 0, 10, 30 or 50 wt% tungsten carbide(WC) are subjected to dry sliding wear against WC-Co and steel ball. In particular an attempt has been made to answer the following important questions:(i) How does the load(from 5 to 20 N) effect sliding wear behaviour of SiC-ceramics against WC-Co and steel counterbodies?(ii) Is there any effect of WC content on friction and wear characteristics of SiC ceramics?(iii) Does the dominant material removal mechanism of SiC ceramics change with the addition of WC or counterbody?(iv) What is the influence of mechanical properties on the sliding wear? Experimental results indicated that coefficient of friction(COF) for the SiC ceramics varied between 0.66 and 0.33 with change in load and counterbodies. Wear volume for SiC ceramics found approximately 6-10 times more against WC-Co as compared against steel. Wear volume changes from 2.0 × 10^(–3)mm^3 to 1.2 × 10^(–2)mm^3 with change in counterbodies for SiC -(10, 30 or 50 wt%) WC composite at 20 N. SiC ceramics indicated abrasion and composites reveal tribochemical wear as major material removal mechanisms. Wear is influenced by the hardness of counterbody and fracture toughness of SiC -WC composites.

关键词： silicon carbide tungsten carbide composites steel sliding wear counterbody

Analysis of silicon-based integrated photovoltaic–electrochemical hydrogen generation system under varying temperature and illumination

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Journal of Energy Chemistry 2017年第1期26卷 72-80页

作者： Vishwa Bhatt Brijesh Tripathi Pankaj Yadav manoj kumar Department of Solar Energy School of TechnologyPandit Deendayal Petroleum UniversityGandhinagar 382007India Department of Science School of TechnologyPandit Deendayal Petroleum UniversityGandhinagar 382007India Department of Electrical Engineering Incheon National UniversityIncheon 406772Republic of Korea

Last decade witnessed tremendous research and development in the area of photo-electrolytic hydrogen generation using chemically stable nanostructured photo-cathode/anode materials. Due to intimately coupled charge separation and photo-catalytic processes, it is very difficult to optimize individual components of such system leading to a very low demonstrated solar-to-fuel efficiency (SFE) of less than 1%. Recently there has been growing interest in an integrated photovoltaic–electrochemical (PV–EC) system based on GaAs solar cells with the demonstrated SFE of 24.5% under concentrated illumination condition. But a high cost of GaAs based solar cells and recent price drop of poly-crystalline silicon (pc-Si) solar cells motivated researchers to explore silicon based integrated PV–EC system. In this paper a theoretical framework is introduced to model silicon-based integrated PV–EC device. The theoretical framework is used to analyze the coupling and kinetic losses of a silicon solar cell based integrated PV–EC water splitting system under varying temperature and illumination. The kinetic loss occurs in the range of 19.1%–27.9% and coupling loss takes place in the range of 5.45%–6.74% with respect to varying illumination in the range of 20–100 mW/cm2. Similarly, the effect of varying temperature has severe impact on the performance of the system, wherein the coupling loss occurs in the range of 0.84%–21.51% for the temperature variation from 25 to 50 °C. © 2016 Science Press

关键词： Electrochemical cells Electrochemical impedance spectroscopy Gallium arsenide Hydrogen production Nanostructured materials Polysilicon Semiconducting gallium Silicon Silicon solar cells Solar power generation

Digitally controlled oscillator design with a variable capacitance XOR gate

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Journal of Semiconductors 2011年第10期32卷 86-92页

作者： manoj kumar Sandeep K.Arya Sujata Pandey Department of Electronics and Communication Engineering Guru Jambheshwar University of Science and TechnologyHisarIndia Amity University NoidaIndia

A digitally controlled oscillator（DCO） using a three-transistor XOR gate as the variable load has been presented.A delay cell using an inverter and a three-transistor XOR gate as the variable capacitance is also proposed. Three-,five- and seven-stage DCO circuits have been designed using the proposed delay *** output frequency is controlled digitally with bits applied to the delay *** three-bit DCO shows output frequency and power consumption variation in the range of 3.2486-4.0267 GHz and 0.6121-0.3901 mW,respectively,with a change in the control word *** five-bit DCO achieves frequency and power of 1.8553-2.3506 GHz and 1.0202-0.6501 mW,respectively,with a change in the control word ***,the seven-bit DCO shows a frequency and power consumption variation of 1.3239-1.6817 GHz and 1.4282-0.9102 mW,respectively, with a varying control word *** power consumption and output frequency of the proposed circuits have been compared with earlier reported circuits and the present approaches show significant improvements.

关键词： digital control oscillator delay cell power consumption variable capacitance voltage controlled oscillators XOR gate