Nonlinear finite element solutions of thermoelastic flexural strength and stress values of temperature dependent graded CNT-reinforced sandwich shallow shell structure

Mehar, Kulmani,Panda, Subrata K. Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.6

This research article reported the nonlinear finite solutions of the nonlinear flexural strength and stress behaviour of nano sandwich graded structural shell panel under the combined thermomechanical loading. The nanotube sandwich structural model is derived mathematically using the higher-order displacement polynomial including the full geometrical nonlinear strain-displacement equations via Green-Lagrange relations. The face sheets of the sandwich panel are assumed to be carbon nanotube-reinforced polymer composite with temperature dependent material properties. Additionally, the numerical model included different types of nanotube distribution patterns for the sandwich face sheets for the sake of variable strength. The required equilibrium equation of the graded carbon nanotube sandwich structural panel is derived by minimizing the total potential energy expression. The energy expression is further solved to obtain the deflection values (linear and nonlinear) via the direct iterative method in conjunction with finite element steps. A computer code is prepared (MATLAB environment) based on the current higher-order nonlinear model for the numerical analysis purpose. The stability of the numerical solution and the validity are verified by comparing the published deflection and stress values. Finally, the nonlinear model is utilized to explore the deflection and the stresses of the nanotube-reinforced (volume fraction and distribution patterns of carbon nanotube) sandwich structure (different core to face thickness ratios) for the variable type of structural parameter (thickness ratio, aspect ratio, geometrical configurations, constraints at the edges and curvature ratio) and unlike temperature loading.

Image formulas and graphical interpretation of fractional derivatives of R-function and G-function

Mehar Chand,Praveen Agarwal,Shilpi Jain,Guotao Wang,K.S. NISAR 장전수학회 2016 Advanced Studies in Contemporary Mathematics Vol.26 No.4

In this paper, our main objective is to establish certain new image formulas of R- and G-functions by applying the operators of fractional derivative involving Appell's function F3(.) due to Saigo-Maeda and the main results interpreted graphically by implementing the MatLab(R2012a). Furthermore, by employing some integral transforms on the resulting formulas, we presented some more image formulas. All the results derived here are of general character and can yield a number of (known and new) results in the theory of special functions.

Multiscale modeling approach for thermal buckling analysis of nanocomposite curved structure

Mehar, Kulmani,Panda, Subrata Kumar Techno-Press 2019 Advances in nano research Vol.7 No.3

The thermal buckling temperature values of the graded carbon nanotube reinforced composite shell structure is explored using higher-order mid-plane kinematics and multiscale constituent modeling under two different thermal fields. The critical values of buckling temperature including the effect of in-plane thermal loading are computed numerically by minimizing the final energy expression through a linear isoparametric finite element technique. The governing equation of the multiscale nanocomposite is derived via the variational principle including the geometrical distortion through Green-Lagrange strain. Additionally, the model includes different grading patterns of nanotube through the panel thickness to improve the structural strength. The reliability and accuracy of the developed finite element model are varified by comparison and convergence studies. Finally, the applicability of present developed model was highlight by enlighten several numerical examples for various type shell geometries and design parameters.

Highway Capacity Through Vissim Calibrated for Mixed Traffic Conditions

Arpan Mehar,Satish Chandra,S. Velmurugan 대한토목학회 2014 KSCE Journal of Civil Engineering Vol.18 No.2

The present study demonstrates applicability of VISSIM software to determine capacity of multilane highways under mixed trafficflow conditions. Traffic flow data collected on a section of four-lane divided highway are used to develop the speed-flow curve. Thesame set of field data is used in VISSIM and simulated speed-flow curve is compared with field curve. It was found that VISSIM inits original form overestimates both speed and capacity of the highway. Driver behaviour parameters CC0 and CC1 are firstdetermined for homogeneous traffic conditions having only one of the four types of vehicles in the stream and then results areaggregated to get the values of these parameters for a mixed traffic stream. Further analysis of field data with calibrated values ofCC0 and CC1 indicated a good match between field and simulated capacity. The procedure is shown to work on another section offour-lane divided highway with paved shoulders, where simulated capacity was 5329 pcu/hr against the field capacity of 5277 pcu/hr.

Nonlinear finite element solutions of thermoelastic flexural strength and stress values of temperature dependent graded CNT-reinforced sandwich shallow shell structure

Kulmani Mehar,Subrata K. Panda 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.6

This research article reported the nonlinear finite solutions of the nonlinear flexural strength and stress behaviour of nano sandwich graded structural shell panel under the combined thermomechanical loading. The nanotube sandwich structural model is derived mathematically using the higher-order displacement polynomial including the full geometrical nonlinear strain-displacement equations via Green-Lagrange relations. The face sheets of the sandwich panel are assumed to be carbon nanotube-reinforced polymer composite with temperature dependent material properties. Additionally, the numerical model included different types of nanotube distribution patterns for the sandwich face sheets for the sake of variable strength. The required equilibrium equation of the graded carbon nanotube sandwich structural panel is derived by minimizing the total potential energy expression. The energy expression is further solved to obtain the deflection values (linear and nonlinear) via the direct iterative method in conjunction with finite element steps. A computer code is prepared (MATLAB environment) based on the current higher-order nonlinear model for the numerical analysis purpose. The stability of the numerical solution and the validity are verified by comparing the published deflection and stress values. Finally, the nonlinear model is utilized to explore the deflection and the stresses of the nanotube-reinforced (volume fraction and distribution patterns of carbon nanotube) sandwich structure (different core to face thickness ratios) for the variable type of structural parameter (thickness ratio, aspect ratio, geometrical configurations, constraints at the edges and curvature ratio) and unlike temperature loading.

Clinico-pathological Profile of Lung Cancer at AIIMS: A Changing Paradigm in India

Malik, Prabhat Singh,Sharma, Mehar Chand,Mohanti, Bidhu Kalyan,Shukla, N.K.,Deo, S.V.S.,Mohan, Anant,Kumar, Guresh,Raina, Vinod Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Background: Lung cancer is one of the commonest and most lethal cancers throughout the world. The epidemiological and pathological profile varies among different ethnicities and geographical regions. At present adenocarcinoma is the commonest histological subtype of non-small cell lung cancer (NSCLC) in most of the Western and Asian countries. However, in India squamous cell carcinoma has been reported as the commonest histological type in most of the series. The aim of the study was to analyze the current clinico-pathological profile and survival of lung cancer at our centre. Materials and Methods: We analyzed 434 pathologically confirmed lung cancer cases registered at our centre over a period of three years. They were evaluated for their clinical and pathological profiles, treatment received and outcome. The available histology slides were reviewed by an independent reviewer. Results: Median age was 55 years with a male:female ratio of 4.6:1. Some 68% of patients were smokers. There were 85.3% NSCLC and 14.7% SCLC cases. Among NSCLCs, adenocarcinoma was the commonest histological subtype after the pathology review. Among NSCLC, 56.8% cases were of stage IV while among SCLC 71.8% cases had extensive stage disease. Some 29% of patients did not receive any anticancer treatment. The median overall and progression free survivals of the patients who received treatment were 12.8 and 7.8 months for NSCLC and 9.1 and 6.8 months for SCLC. Conclusions: This analysis suggests that adenocarcinoma may now be the commonest histological subtype also in India, provided a careful pathological review is done. Most of the patients present at advanced stage and outcome remains poor.

Hypoxia-Induced Biological Changes Indicate the Presence of an Oxygen Sensor in Fruits and Cut Carnations

Theophanes Solomos,Prabodh Trivedi,Mehar Asif 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Modal analysis of FG sandwich doubly curved shell structure

Sushmita Dash,Kulmani Mehar,Nitin Sharma,Trupti R. Mahapatra,Subrata K. Panda 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.6

The modal frequency responses of functionally graded (FG) sandwich doubly curved shell panels are investigated using a higher-order finite element formulation. The system of equations of the panel structure derived using Hamilton’s principle for the evaluation of natural frequencies. The present shell panel model is discretised using the isoparametric Lagrangian element (nine nodes and nine degrees of freedom per node). An in-house MATLAB code is prepared using higher-order kinematics in association with the finite element scheme for the calculation of modal values. The stability of the opted numerical vibration frequency solutions for the various shell geometries i.e., single and doubly curved FG sandwich structure are proven via the convergence test. Further, close conformance of the finite element frequency solutions for the FG sandwich structures is found when compared with the published theoretical predictions (numerical, analytical and 3D elasticity solutions). Subsequently, appropriate numerical examples are solved pertaining to various design factors (curvature ratio, core-face thickness ratio, aspect ratio, support conditions, power-law index and sandwich symmetry type) those have the significant influence on the free vibration modal data of the FG sandwich curved structure.

Patterns of Tobacco Consumption among Indian Men with Schizophrenia Compared to Their Male Siblings

Saurabh Vatss,Harpreet Mehar,Triptish Bhatia,Jan Richard,Ruben C Gur,Raquel E Gur,Vishwajit L. Nimgaonkar,Smita N. Deshpande 대한신경정신의학회 2012 PSYCHIATRY INVESTIGATION Vol.9 No.3

Objective-Tobacco consumption among patients with schizophrenia has been investigated extensively in western countries, but there is a dearth of studies in India, where socio-economic and cultural variables are different. This study aims to investigate the patterns of tobacco consumption among schizophrenia patients compared with their non-psychotic siblings. Methods-Consenting, successive male outpatients diagnosed with schizophrenia (n=100, DSM-IV criteria), and their non-psychotic brothers (n=100) were compared. Following a structured diagnostic interview, detailed information about tobacco consumption (including smokeless tobacco) was obtained using the Fagerstrom Test for Nicotine Dependence for smoked tobacco, and FTND-smokeless tobacco. The University of Pennsylvania Computerized Neurocognitive battery (CNB) was administered to a sub-group of patients (n=48). Results-Schizophrenia patients initiated tobacco use at a significantly earlier age than their brothers, but there was no significant difference with regard to type, quantity or frequency of tobacco use (smoke or smokeless varieties). Patients who consumed tobacco had signi-ficantly higher positive symptom scores compared with non-users (p=0.043). There were no significant differences between nicotine dependent and non-dependent patients with regard to CNB domains except attention. Conclusion-Patterns of tobacco consumption were similar among schizophrenia patients and their non-psychotic brothers. Tobacco use was associated with increased positive symptom scores, but there were no significant differences in cognitive measures among nicotine dependent and non-dependent patients.

CERTAIN INTEGRALS INVOLVING ₂F₁, KAMPÉDE FÉRIET FUNCTION AND SRIVASTAVA POLYNOMIALS

Agarwal, Praveen,Chand, Mehar,Choi, Junesang Korean Mathematical Society 2016 대한수학회논문집 Vol.31 No.2

A remarkably large number of integrals whose integrands are associated, in particular, with a variety of special functions, for example, the hypergeometric and generalized hypergeometric functions have been recorded. Here we aim at presenting certain (presumably) new and (potentially) useful integral formulas whose integrands are involved in a product of $_2F_1$, Srivastava polynomials, and $Kamp{\acute{e}}$ de $F{\acute{e}}riet$ functions. The main results are derived with the help of some known definite integrals obtained earlier by Qureshi et al. [4]. Some interesting special cases of our main results are also considered.