Faculty Publications
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Item Stress analysis of Antisymmetric angle ply sandwich plates- analytical evaluation of refined higher order shear deformation theories(CAFET INNOVA Technical Society 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2011) Swaminathan, K.; Sangwai, G.R.In this paper two refined higher order computational models with 9 DOF and 12 DOF are considered. Analytical formulation developed and solutions obtained for the first time using these models for the stress analysis of antisymmetric angle ply sandwich plate. In addition, higher order model proposed by Reddy and the first order model already reported in the literature are also considered for the evaluation. A simply supported plate with SS-2 boundary conditions is considered for the analysis. The equations of equilibrium are obtained using Principle of Minimum Potential Energy (PMPE). Solutions are obtained in closed form using Navier’s technique. In-plane stresses are computed using the three dimensional constitutive relationships and the transverse stresses by post processing technique. Extensive numerical results using all the models are compared with 3D elasticity solutions already available in the literature to decide the accuracy of model. After establishing accuracy of the solution method benchmark results and comparison of solutions are presented for multilayer sandwich plates. It is observed that ESL models with twelve DOF are accurate, efficient and simple. © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Vibrational spectra of Ruthenium Carbide structures yielded by the structure search employing evolutionary algorithm(Elsevier Ltd, 2015) Harikrishnan, G.; Ajith, K.M.; Chandra, S.; Valsakumar, M.C.Out of the three dynamically stable structures of Ruthenium Carbides yielded by the exhaustive structure search employing evolutionary algorithm, Born effective charges are computed for the semiconducting RuC in Zinc blende structure using density functional perturbation theory. Using the phonon frequencies and the Born effective charge tensors of Ru and C in this structure, infrared spectrum is generated for this system. Computations of these dynamical quantities and IR spectra from first principles can be helpful in the unambiguous determination of the stoichiometry and structure by comparison of the experimental measurements with the computational predictions. The positive formation energies of the three systems show that high pressure and possibly high temperature may be necessary for their synthesis. Formation energies of these systems at different pressures are computed. One of the structurally stable systems, Ru3C with hexagonal structure (P6¯m2), has negative formation energy at 200 GPa. The system reported from the first synthesis of Ruthenium Carbide also has the same symmetry, though it has a different stoichiometry. © 2015 Elsevier Ltd. All rights reserved.Item Numerical simulation of oscillating lid driven square cavity(Elsevier B.V., 2018) Indukuri, J.V.; Maniyeri, R.This paper aim to develop a two-dimensional computational model to study the fluid dynamic behaviour in a square cavity driven by an oscillating lid using staggered grid based finite volume method. Firstly the developed computational model is validated with that of other researcher's results for the case of finite wall motion. Later the numerical simulations are performed for the case of top wall oscillations for various combinations of Reynolds number and frequencies. From these simulations an optimum frequency is chosen and then with the optimum frequency the simulations are carried out to explore the vortex behaviour for the cases of parallel wall oscillations (both top and bottom walls moving in the same direction) and anti-parallel wall oscillations (both top and bottom walls moving in the opposite direction). From these simulations it may be concluded that Re = 1000 is medium range of operation for better mixing inside the cavity for the cases of parallel and anti-parallel wall oscillations. © 2017 Faculty of Engineering, Alexandria UniversityItem Numerical study of forced convection heat transfer in an oscillating lid driven cavity with heated top wall(International Information and Engineering Technology Association info@iieta.org, 2018) Indukuri, J.V.; Maniyeri, R.The present work is aimed to study the fluid flow and heat transfer behaviour in an oscillating lid-driven cavity using finite volume method by developing a two-dimensional computational model. Firstly, the developed computational model is validated by comparing our numerical results with that of the other researcher's results for the case of wall moving with finite motion. Next, the simulations are conducted for oscillating cavity problem with top wall oscillation for Reynolds number (Re =5 00) and frequency (?=2?/6). Later, the simulations are carried out for cases of oscillating parallel wall (upper and lower walls oscillating with sync) and oscillating anti-parallel wall (upper and lower walls oscillating with reverse sync) with the same optimum frequency and fixed Reynolds number (Re = 500). Secondly, the same optimum frequency is used to study the heat transfer characteristics in an oscillating lid-driven square cavity with heated top wall and lower cold wall for various Reynolds numbers (Re = 100-1000) and Prandtl numbers (Pr = 0.2 to 1.0). From this study, it is found that for high Prandtl number case (Pr = 1.0) the flow of high temperature isotherms inside the cavity is more when compared with low Prandtl number cases due to increase in molecular diffusion of momentum. © 2018 International Information and Engineering Technology Association.Item Computational insights into factor affecting the potency of diaryl sulfone analogs as Escherichia coli dihydropteroate synthase inhibitors(Elsevier Ltd, 2019) Das, B.K.; PV, P.; Chakraborty, D.Dihydropteroate synthase (DHPS) is an alluring target for designing novel drug candidates to prevent infections caused by pathogenic Escherichia coli strains. Diaryl Sulfone (SO) compounds are found to inhibit DHPS competitively with respect to the substrate pABA (p-aminobenzoate). The extra aromatic ring of diaryl sulfone compounds found to stabilize them in highly flexible pABA binding loops. In this present study, a statistically significant 3D-QSAR model was developed using a data set of diaryl sulfone compounds. The favourable and unfavourable contributions of substitutions in sulfone compounds were illustrated by contour plot obtained from the developed 3D-QSAR model. Molecular docking calculations were performed to investigate the putative binding mode of diaryl sulfone compounds at the catalytic pocket. DFT calculations were carried out using SCF approach, B3LYP- 6-31 G (d) basis set to compute the HOMO, LUMO energies and their respective location at pABA binding pocket. Further, the developed model was validated by FEP (Free Energy Perturbation) calculations. The calculated relative free energy of binding between the highly potent and less potent sulfone compound was found to be ?3.78 kcal/ mol which is comparable to the experimental value of ?5.85 kcal/mol. A 10 ns molecular dynamics simulation of inhibitor and DHPS confirmed its stability at pABA catalytic site. Outcomes of the present work provide deeper insight in designing novel drug candidates for pathogenic Escherichia coli strains. © 2018 Elsevier LtdItem Kantorovich-Like Convergence Theorems for Newton’s Method Using Restricted Convergence Domains(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2019) Argyros, I.K.; George, S.The convergence set for Newton’s method is small in general using Lipschitz-type conditions. A center-Lipschitz-type condition is used to determine a subset of the convergence set containing the Newton iterates. The rest of the Lipschitz parameters and functions are then defined based on this subset instead of the usual convergence set. This way the resulting parameters and functions are more accurate than in earlier works leading to weaker sufficient semi-local convergence criteria. The novelty of the paper lies in the observation that the new Lipschitz-type functions are special cases of the ones given in earlier works. Therefore, no additional computational effort is required to obtain the new results. The results are applied to solve Hammerstein nonlinear integral equations of Chandrasekhar type in cases not covered by earlier works. © 2018, © 2019 Taylor & Francis Group, LLC.Item Finite difference method based analysis of bio-heat transfer in human breast cyst(Elsevier Ltd, 2019) Patil, H.M.; Maniyeri, R.Bio-heat transfer is a branch of bio-medical engineering which has its foundation linked to engineering disciplines of heat transfer. The thermal properties and behaviour of various malfunctioning tissues in human body varies as compared with normal tissues. Among various cancer tissues one which is commonly diagnosed in women is breast cyst (cancer causing fluid). The aim of present work is to develop one, two and three-dimensional computational models to study bio-heat transfer problems using finite difference method. First of all, a numerical model based on finite difference method is developed to solve Pennes's bio-heat transfer equation in one-dimension to get temperature profiles normal to skin surface and validated with existing analytical solutions. Secondly, the numerical model is extended to study the thermal behaviour of human breast section embedded with cyst using two-dimensional cylindrical coordinate systems and validated with previous researcher's results. The effect of size, location and presence of multiple cysts on surface temperature is studied. Lastly, the work is extended for the case of three-dimensional breast section with cyst located at the centre. The numerical results obtained using one, two and three-dimensional computational models will be highly helpful in the early detection of breast cancer tissues and also the location of it inside the body. © 2019Item Probabilistic Seismic Hazard Assessment of Mangalore and Its Adjoining Regions, A Part of Indian Peninsular: An Intraplate Region(Birkhauser Verlag AG, 2019) Shreyasvi, C.; Venkataramana, K.; Chopra, S.; Rout, M.M.The Southwestern part of India investigated in the present study mainly comprises of states such as Goa, north Kerala and a major portion of Karnataka. A comprehensive regional seismic catalog has been compiled spanning over 190 years apart from a few prehistoric events from the early 16th century. The classical Cornel–McGuire approach has been incorporated in the estimation of seismic hazard. The seismic sources are modeled as area sources and the entire study region is divided into four seismogenic source zones. The uncertainties involved in the formulation of the seismic source model and ground motion prediction model has been discussed in detail. Further, the procedure for selecting appropriate GMPEs involves the evaluation of multidimensional (M, R, T) ground motion trends and performance against observed macroseismic data. The epistemic uncertainty in the estimation of seismicity parameters and ground motion prediction equations (GMPEs) has been addressed using logic tree computation. The results of the hazard analysis demonstrate that the existing seismic code underestimates the seismic potential of seismic zone II (BIS 1893) areas. The de-aggregation of the predicted seismic hazard revealed earthquakes of magnitude range (Mw) 4–6 occurring within a distance of 35kms to be most influential for any given site of interest. Sensitivity analysis has been performed for crucial input parameters in the formulation of seismic source and ground motion models. Site amplification study has been carried out using topographic slope as a proxy to shear velocity in the top 30 m (Vs30). A maximum of 60% to 80% amplification has been observed in the study area. The seismic hazard maps in terms of PGA have been plotted for the seismic hazard estimated at the bedrock level as well as the surface level for 2% and 10% probability of exceedance in 50 years. The hazard estimation specifically for the southern part of the west coast is the first of its kind. The investigation suspects mining-induced seismicity in Bellary and Raichur districts though there is no mention of this in the prior literature. © 2019, Springer Nature Switzerland AG.Item Computing the Moore-Penrose inverse using its error bounds(Elsevier Inc. usjcs@elsevier.com, 2020) Stanimirovi?, P.S.; Roy, F.; Gupta, D.K.; Srivastava, S.A new iterative scheme for the computation of the Moore-Penrose generalized inverse of an arbitrary rectangular or singular complex matrix is proposed. The method uses appropriate error bounds and is applicable without restrictions on the rank of the matrix. But, it requires that the rank of the matrix is known in advance or computed beforehand. The method computes a sequence of monotonic inclusion interval matrices which contain the Moore-Penrose generalized inverse and converge to it. Successive interval matrices are constructed by using previous approximations generated from the hyperpower iterative method of an arbitrary order and appropriate error bounds of the Moore-Penrose inverse. A convergence theorem of the introduced method is established. Numerical examples involving randomly generated matrices are presented to demonstrate the efficacy of the proposed approach. The main property of our method is that the successive interval matrices are not defined using principles of interval arithmetic, but using accurately defined error bounds of the Moore-Penrose inverse. © 2019 Elsevier Inc.Item Design of high throughput asynchronous FIR filter using gate level pipelined multipliers and adders(John Wiley and Sons Ltd vgorayska@wiley.com Southern Gate Chichester, West Sussex PO19 8SQ, 2020) Girija Sravani, K.; Rao, R.This work presents the design of an asynchronous digital finite impulse response (FIR) filter suitable for high-performance partial response maximum likelihood (PRML) read channel ICs. A high throughput, low latency FIR filter is the basic requirement for the equalization process in read channels. To achieve the enhancement in speed and reduction in latency of the FIR filter, its computational units are deeply pipelined using high-capacity hybrid (HC-hybrid) logic pipeline method. The designed FIR filter has been simulated using UMC-180 nm and UMC-65 nm technologies. Simulation results show that the asynchronous digital FIR filter can operate up to a throughput of 1.17 Giga items/s in 180 nm and 2.3 Giga items/s in 65 nm technology yet with the latency in the order of ns. © 2020 John Wiley & Sons, Ltd.