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Generalized Bleustein-Gulyaev type waves in layered porous piezoceramic structure

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Applied Mathematics and Mechanics(English Edition) 2015年第9期36卷 1223-1242页

作者： A.K.vASHISHTH A.DAHIYA v.gupta Department of Mathematics Kurukshetra University

The propagation of a Bleustein-Gulyaev （B-G） type wave in a structure consisting of multiple layers and a half-space of porous piezoelectric materials is theoreti- cally studied. The solutions of the problem in terms of the mechanical displacements and electric potential functions are obtained for each layer and the half-space. The dispersion equation is obtained for electrically open and shorted boundary conditions by use of the transfer matrix method. A peculiar kind of B-G waves is investigated, which can propagate only in the layer over the half-space. The relationship between the piezoelectric constants and the dielectric constants is found for the existence of a peculiar kind of propagation modes. The numerical results in terms of the phase velocity and the electromechanical coupling factor with different thicknesses of the layer stack are presented.

关键词： Bleustein-Gulyaev (B-G) type wave electro-mechanical coupling porouspiezoceramic transfer matrix

Ensembles vs. information theory: supporting science underuncertainty

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Frontiers of Earth Science 2018年第4期12卷 653-660页

作者： Grey S.NEARING Hoshin v.gupta University of Alabama Department of Geological SciencesTuscaloosaAL 35294-1152USA University of Arizona Department of Hydrology and Atmospheric SciencesTucsonAZ 85721-0158USA

Multi-model ensembles are one of the most common ways to deal with epistemic uncertainty in hydrology. This is a problem because there is no known way to sample models such that the resulting ensemble admits a measure that has any systematic (i.e., asymptotic, bounded, or consistent) relationship with uncertainty. Multi-model ensembles are effectively sensitivity analyses and cannot - even partially - quantify uncertainty. One consequence of this is that multi-model approaches cannot support a consistent scientific method - in particular, multi-model approaches yield unbounded errors in inference. In contrast, information theory supports a coherent hypothesis test that is robust to (i.e., bounded under) arbitrary epistemic uncertainty. This paper may be understood as advocating a procedure for hypothesis testing that does not require quantifying uncertainty, but is coherent and reliable (i.e., bounded) in the presence of arbitrary (unknown and unknowable) uncertainty. We conclude by offering some suggestions about how this proposed philosophy of science suggests new ways to conceptualize and construct simulation models of complex, dynamical systems.

关键词： information theory multi-model ensembles Bayesian methods uncertainty quantification hypothesis testing

Lithium bromide catalyzed solvent free method for synthesis of 2-substituted benzimidazoles and imidazopyridines

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Chinese Chemical Letters 2010年第5期21卷 519-523页

作者： Deepak v.Dekhane Shivaji S.Pawar Sunil v.gupta Murlidhar S.Shingare Shivaji N.Thore Department of Chemistry Vinyakrao Patil Mahavidyala VaijapurAurangabad 423701MSIndia Department of Chemistry Dr.Babasaheb Ambedkar Marathwada UniversityAurangabad 431004MSIndia

The first successful lithium bromide mediated solvent free condensation of arylenediamine and esters to obtain 2-substituted benzimidazole and imidazopyridine in good to excellent yields is described.

关键词： Benzimidazoles Arylenediamine Aliphatic esters Lithium bromide Imidazopyridines

Intricacies during pregnancy with gestational diabetes mellitus

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World Journal of Clinical Cases 2025年第1期13卷 62-64页

作者： Richa Rattan Rimesh Pal Parul Chawla gupta Arvind Kumar Morya Ripunjay Prasad Department of Endocrinology Post Graduate Institute of Medical Education and ResearchChandigarh 160012India Department of Ophthalmology Post Graduate Institute of Medical Education and ResearchChandigarh 160012PunjabIndia Department of Ophthalmology All India Institute of Medical SciencesHyderabad 508126TelanganaIndia Department of Ophthalmology RP Eye InstituteDelhi 110001India

The study by Cao et al aimed to identify early second-trimester biomarkers that could predict gestational diabetes mellitus(GDM)development using advanced proteomic techniques,such as Isobaric tags for relative and absolute quantitation isobaric tags for relative and absolute quantitation and liquid chromatography-mass spectrometry liquid chromatography-mass *** analysis revealed 47 differentially expressed proteins in the GDM group,with retinol-binding protein 4 and angiopoietin-like 8 showing significantly elevated serum levels compared to *** these findings are promising,the study is limited by its small sample size(n=4 per group)and lacks essential details on the reproducibility and reliability of the protein quantification methods ***,the absence of experimental validation weakens the interpretation of the protein-protein interaction network identified through bioinformatics *** study's focus on second-trimester biomarkers raises concerns about whether this is a sufficiently early period to implement preventive interventions for *** GDM risk during the first trimester or pre-conceptional period may offer more clinical *** its limitations,the study presents valuable insights into potential GDM biomarkers,but larger,well-validated studies are needed to establish their predictive utility and generalizability.

关键词： Gestational diabetes mellitus Biomarkers Differentially expressed proteins Retinol-binding protein 4 Angiopoietin-like 8 Proteomics Lifestyle interventions Early prediction

Motion of a permeable shell in a spherical container filled with non-Newtonian fluid

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Applied Mathematics and Mechanics(English Edition) 2017年第12期38卷 1697-1708页

作者： v.MISHRA B.R.gupta Department of Mathematics Jaypee University of Engineering and TechnologyMadhya Pradesh 473226India

This paper presents an analytical study of creeping motion of a permeable sphere in a spherical container filled with a micro-polar fluid. The drag experienced by the permeable sphere when it passes through the center of the spherical container is studied. Stream function solutions for the flow fields are obtained in terms of modified Bessel functions and Gegenbauer functions. The pressure fields, the micro-rotation components, the drag experienced by a permeable sphere, the wall correction factor, and the flow rate through the permeable surface are obtained for the frictionless impermeable spherical container and the zero shear stress at the impermeable spherical container. variations of the drag force and the wall correction factor with respect to different fluid parameters are studied. It is observed that the drag force, the wall correction factor, and the flow rate are greater for the frictionless impermeable spherical container than the zero shear stress at the impermeable spherical container. Several cases of interest are deduced from the present analysis.

关键词： micro-polar fluid permeable sphere Darcy law stream function drag force wall correction factor spherical container

Microstructural image based convolutional neural networks for efficient prediction of full-field stress maps in short fiber polymer composites

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Defence Technology（防务技术） 2023年第6期24卷 58-82页

作者： S.gupta T.Mukhopadhyay v.Kushvaha Department of Civil Engineering Indian Institute of Technology JammuJ&KIndia Department of Aerospace Engineering Indian Institute of Technology KanpurUPIndia

The increased demand for superior materials has highlighted the need of investigating the mechanical properties of composites to achieve enhanced constitutive ***-reinforced polymer composites have emerged as an integral part of materials development with tailored mechanical ***,the complexity and heterogeneity of such composites make it considerably more challenging to have precise quantification of properties and attain an optimal design of structures through experimental and computational *** order to avoid the complex,cumbersome,and labor-intensive experimental and numerical modeling approaches,a machine learning(ML)model is proposed here such that it takes the microstructural image as input with a different range of Young’s modulus of carbon fibers and neat epoxy,and obtains output as visualization of the stress component S11(principal stress in the x-direction).For obtaining the training data of the ML model,a short carbon fiberfilled specimen under quasi-static tension is modeled based on 2D Representative Area Element(RAE)using finite element *** composite is inclusive of short carbon fibers with an aspect ratio of 7.5that are infilled in the epoxy systems at various random orientations and positions generated using the Simple Sequential Inhibition(SSI)*** study reveals that the pix2pix deep learning Convolutional Neural Network(CNN)model is robust enough to predict the stress fields in the composite for a given arrangement of short fibers filled in epoxy over the specified range of Young’s modulus with high *** CNN model achieves a correlation score of about 0.999 and L2 norm of less than 0.005 for a majority of the samples in the design spectrum,indicating excellent prediction *** this paper,we have focused on the stage-wise chronological development of the CNN model with optimized performance for predicting the full-field stress maps of the fiber-reinforced composite ***

关键词： Micromechanics of fiber-reinforced composites Machine learning assisted stress prediction Microstructural image-based machine learning CNN based stress analysis

Instability of binary nanofluids with magnetic field

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Applied Mathematics and Mechanics(English Edition) 2015年第6期36卷 693-706页

作者： U.gupta J.SHARMA v.SHARMA Dr.S.S.Bhatnagar University Institute of Chemical Engineering and Technology Panjab University Energy Research Centre Panjab University Department of Mathematics Himachal Pradesh University

The present paper investigates the effects of a vertical magnetic field on the double diffusive nanofluid convection, The effects of the Brownian motion and ther- mophoresis due to the presence of nanoparticles and the effects of the Dufour and Sorer parameters due to the presence of solute are included in the investigated model. The normal mode technique is used to solve the conservation equations. For the analytical study, valid approximations are made in the complex expression for the Rayleigh number to get useful and interesting results. The bottom heavy binary nanofluids are more stable than the regular binary fluids, while the top heavy binary nanofluids are less stable than the regular binary fluids. The critical wave number and the critical Rayleigh number in- crease whereas the frequency of oscillation （for the bottom heavy configuration） decreases when the Chandrasekhar number increases. The numerical results for the alumina-water nanofiuid are studied by use of the MATHEMATICA software.

关键词： natural convection binary nanofluid Brownian motion thermophoresis,Chandrasekhar number

Application of geospatial modelling technique in delineation of fluoride contamination zones within Dwarka Basin, Birbhum, India

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Geoscience Frontiers 2017年第5期8卷 1105-1114页

作者： Raju Thapa Srimanta gupta D.v.Reddy Department of Environmental Science The University of Burdwan Burdwan 713104 West Bengal India CSIR-National Geophysical Research Institute Hyderabad 500007 Telangana India

Dwarka River Basin is one of the fluoride affected river basin in Birbhum, West Bengal. In the present research work, various controlling factors for fluoride contamination in groundwater i.e., geology, aquifer type, groundwater table, soil, rainfall, geomorphology, drainage density, land use land cover, lineament and fault density, slope and elevation were considered to delineate the potential fluoride contamination zones within Dwarka River Basin in Birbhum. Assigning weights and ranks to various inputs factor class and their sub-class respectively was carried out on the basis of knowledge driven method. Weighted overlay analysis was carried out to generate the final potential fluoride contamination zones which are classified into two broad classes i.e., 'high' and 'low', and it is observed that major portion of the study area falls under low fluoride contamination category encompassing 88.61% of the total area which accounts for 759.48 km^2 and high fluoride contaminated region accounts for 11.40% of the total study area encompassing an area of about 97.67 km^2. Majority of high fluoride areas fall along the flood plain of Dwarka River Basin. Finally, for validation 197 reported points within Dwarka having fluoride in underground water are overlaid and an overall accuracy of 92.15% is observed. An accuracy of 83.21% and84.24% is obtained for success and prediction rate curve respectively.

关键词： Fluoride Groundwater Weighted overlay method Potential fluoride contamination zone Dwarka Basin India

Synthesis,characterization and application of PvA/ionic liquid mixed matrix membranes for pervaporation dehydration of isopropanol

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Chinese Journal of Chemical Engineering 2017年第10期25卷 1402-1411页

作者： Ganesh B.Thorat Smita gupta Z.v.P.Murthy Department of Chemical Engineering Sardar Vallabhbhai National Institute of Technology Surat 395007 Gujarat India

In this study,polyvinyl alcohol(PvA)–ionic liquid(IL) membranes were prepared for the separation of isopropyl alcohol(IPA)–water azeotropic mixtures by ***-IL composite membranes were prepared by simple solvent evaporation method using four ILs,viz.,1-n-butyl-3-methylimidazolium chloride(BMIMCl),1-hexyl-3-methylimidazolium chloride(HMIMCl),1-hexyl-3-methylimidazolium tetra fluoroborate(HMIMBF4) and 1-octyl-3-methylimidazolium chloride(OMIMCl).Three ILs were used to study the effect of alkyl chain on the pervaporation *** study had focused on the effect feed water concentration from 10%–40%and effect of feed temperature from 50–80°*** properties of all the membranes were studied using Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM) and contact angle *** Arrhenius activation energies for permeation were estimated to be in the range 4–12 kJ·mol-1 from the temperature dependent permeation values.

关键词： Composite membranes Ionic liquids Dehydration Isopropanol Pervaporation