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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 relationships.Fiber-reinforced polymer composites have emerged as an integral part of materials development with tailored mechanical properties.However,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 approaches.In 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 analysis.the 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)process.the 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 accuracy.the 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 capability.In 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 specimens.the development of such a robust and efficient alg

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

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Vibration and Buckling Analyses of Sandwich Plates Containing Functionally Graded Metal Foam Core

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Acta Mechanica Solida Sinica 2022年第4期35卷 587-602页

作者： A.Garg H.D.Chalak L.Li M.-O.Belarbi R.Sahoo t.mukhopadhyay Department of Civil Engineering National Institute of TechnologyKurukshetraHaryana136119India Department of Aerospace Engineering Indian Institute of TechnologyKanpurUttar Pradesh208016India State Key Lab of Digital Manufacturing Equipment and technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China Laboratoire de Génie Energétique et Matériaux LGEMFacultéde la science et de lo TechnologieUniversitéde BiskraB.P.145R.P.07000BiskraAlgeria Department of Civil Engineering Indian Institute of TechnologyBanaras Hindu UniversityVaranasiUttar Pradesh221005India

In the present work,free vibration and buckling analyses of sandwich plates with various functionally graded foam cores are carried out.Foam cores are assumed to be made of metal,and three different configurations of the porous distribution in the core layer are taken into consideration.to carry out a comparative study between the distributions of pores in the core foam,the mass of foam in all three cases is kept the same.the vibration and buckling behaviors of skew plates are also analyzed as a part of the current investigation.the principle of minimization of potential energy and Hamilton’s principle are used for the derivation of the governing equations,while a C-0 finite element-based higher-order zigzag formulation is developed to solve the free vibration and buckling problems.the influences of gradation laws,boundary conditions,skew angle and geometry of plates are studied in detail for the dynamic and stability characteristics.It is found that both the non-dimensional natural frequency and buckling load decrease with the increase in the thickness of the metal foam cores,while they show an increasing trend as the skew angle of the plate increases.

关键词： Sandwich plate Metal foam core Functionally graded core Finite element Skew plate

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Probabilistic Analysis and Design of HCP Nanowires:An Efficient Surrogate Based Molecular Dynamics Simulation Approach

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Journal of Materials Science & technology 2016年第12期32卷 1345-1351页

作者： t.mukhopadhyay A.Mahata S.Dey S.Adhikari College of Engineering Swansea UniversitySwanseaUnited Kingdom Department of Materials Science and Engineering Missouri University of Science and TechnologyRollaMOUSA Indian Institute of Science BangaloreIndia Leibniz-Institut fur Polymerforschung Dresden e.V. DresdenGermany

We investigate the dependency of strain rate,temperature and size on yield strength of hexagonal close packed（HCP） nanowires based on large-scale molecular dynamics（MD） simulation.A variance-based analysis has been proposed to quantify relative sensitivity of the three controlling factors on the yield strength of the material.One of the major drawbacks of conventional MD simulation based studies is that the simulations are computationally very intensive and economically expensive.Large scale molecular dynamics simulation needs supercomputing access and the larger the number of atoms,the longer it takes time and computational resources.For this reason it becomes practically impossible to perform a robust and comprehensive analysis that requires multiple simulations such as sensitivity analysis,uncertainty quantification and optimization.We propose a novel surrogate based molecular dynamics（SBMD）simulation approach that enables us to carry out thousands of virtual simulations for different combinations of the controlling factors in a computationally efficient way by performing only few MD simulations.Following the SBMD simulation approach an efficient optimum design scheme has been developed to predict optimized size of the nanowire to maximize the yield strength.Subsequently the effect of inevitable uncertainty associated with the controlling factors has been quantified using Monte Carlo simulation.though we have confined our analyses in this article for Magnesium nanowires only,the proposed approach can be extended to other materials for computationally intensive nano-scale investigation involving multiple factors of influence.

关键词： hcp-nanowire Yield strength Surrogate Monte Carlo simulation Uncertainty in nanoscale Sensitivity

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丰质子同位素^(65)As的初步观察

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高能物理与核物理 1992年第7期16卷 647-650页

作者：徐瑚珊 I.tANIHAtA t.KUBO M.YANOKURA K.KIMURA 姜承烈白希祥 A.CHAKRABARtI t.mukhopadhyay 中国科学院近代物理研究所兰州730000 日本国理化学研究所日本国九州大学中国原子能科学研究院北京102413 VECC Bhabha Atomic Research CentreCulcutta INDIA

使用20.11A MeV ^(64)Zn束轰击17.2 mg/cm^2的Be靶,初步观察到了丰质子同位素^(65)As。采用由磁分析器、PPAC、电离室和PSSD组成的探测系统,成功地鉴別了反应产物的电荷态、原子系数和质量数。

关键词：丰质子同位素砷65 电荷态

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Prevalence and impact of diabetes and prediabetes on presentation and complications of primary hyperaldosteronism at diagnosis

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World Journal of Clinical Cases 2024年第18期12卷 3332-3339页

作者： Debmalya Sanyal Pradip mukhopadhyay Sujoy Ghosh Department of Endocrinology NHRTIICS&KPC Medical CollegeKolkata 700032West BengalIndia Department of Endocrinology IPGME&R and SSKM HospitalKolkata 700020West BengalIndia Department of Endocrinology IPGME&RKolkata 700020West BengalIndia

BACKGROUND Primary hyperaldosteronism(PH)is considered to contribute to increased risk of developing type 2 diabetes mellitus(t2DM)and prediabetes.Both PH and DM are associated with increased risk for hypertension,cardiovascular diseases,and chronic kidney diseases.However,data on prevalence of t2DM and prediabetes in PH,and impact of t2DM and prediabetes on presentation and cardio renal complications in PH at presentation is sparse.AIM to determine the prevalence of t2DM and prediabetes in PH at diagnosis and impact on presentation and complications of PH.MEtHODS A retrospective cohort study was conducted in tertiary care settings in individuals with confirmed diagnosis of PH at presentation.Demographic variables,clinical presentations,duration and degree of hypertension,complications,laboratory parameters including sodium,potassium levels,plasma aldosterone concentration(PAC),plasma renin activity(PRA),and aldosterone to renin ratio(ARR)and cardio-renal parameters were collected.Comparison was done between three groups:PH with no DM(Group A)or with pre-diabetes(Group B)or with t2DM(Group C).Ptatistically significant.RESULtS Among 78 individuals with confirmed PH,62%had pre-diabetes or diabetes;with 37%having DM.Mean duration of t2DM was 5.97±4.7 years.the mean levels of glycaemic parameters among the group A vs B vs C individuals were fasting plasma glucose(mg/dL):87.9±6.5,105.4±9.02,130.6±21.1;post prandial plasma glucose(mg/dL):122.7±9.8,154.9±14,196.7±38.0;glycated haemoglobin(%)(5.3±0.2,5.9±0.2,7.5±0.6,Ptively.there was no significant difference in the biochemical parameters(PAC,PRA,ARR,sodium,potassium levels),presentation and complications between the groups.Cardio renal parameters or degree and duration of hypertension were comparable between the groups.CONCLUSION Significant prevalence of t2DM and prediabetes in PH at diagnosis does not impact its presentation or complications.Early screening for undetected PH in t2DM and prediabetes subjects with hypertension may prevent complic

关键词： Primary hyperaldosteronism Diabetes Prediabetes Hypertension Aldosterone Aldosterone to renin ratio

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Late Ordovician Mass Extinction: Earth, fire and ice

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National Science Review 2024年第1期11卷 51-65页

作者： David A.t.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

the Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. these symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

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Preparation of microparticles and nanoparticles using membrane-assisted dispersion,micromixing,and evaporation processes

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Particuology 2024年第1期84卷 30-44页

作者： Goran t.Vladisavljevic Chemical Engineering Department Loughborough UniversityLoughboroughLeicestershire LE113TUUnited Kingdom

Synthetic microporous membranes are increasingly used for energy-efficient and controlled production of micro-and nanoparticles and micro-and nanoemulsions with tuneable morphology and physico-chemical properties through various micromixing,emulsification,and evaporation processes.In emul-sification processes,the membrane pores are used for dispersed phase injection and size-controlled generation of droplets and droplet-templated particles.In micromixing processes,membrane is utilised as a micromixer for mixing two miscible liquids,usually solvent and antisolvent-rich solutions,which leads to the creation of supersaturation and subsequent nanoprecipitation or crystallisation.In mem-brane evaporation processes,membrane is used to prevent phase dispersion while allowing efficient molecular diffusion of solvent and/or antisolvent vapour through gas-filled pores.Membrane dispersion processes can be operated continuously by decoupling shear stress on the membrane surface from cross flow using tube insets,flow pulsations,swirling flow,membrane oscillations or membrane rotations.Droplet generation and solidification can be performed continuously in a single pass by connecting membrane module with a downstream reactor.Membrane dispersion processes can be used for pro-duction of nanoparticles such as nanovesicles(liposomes,micelles,ethosomes,and niosomes),nanogels,polymeric,lipid and metallic nanoparticles,and nanocrystals.the main advantages of membrane-assisted particle generation are in low energy consumption,controlled geometry and hydrodynamic conditions at the microscale level,flexible throughput due to modular and scalable design of membrane devices,and a wide choice of available microporous membranes with various wall porosities,wetta-bilities,pore sizes,and pore morphologies to suit different applications.

关键词： Nanoparticles Microparticles Nanoemulsions Microemulsions Microporous membrane Crystallisation Flash nanoprecipitation Emulsification Zero liquid discharge

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Eliciting CD4-mimicking broadly neutralizing antibodies:new avenues towards the rational design of an HIV vaccine

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Signal transduction and targeted therapy 2024年第3期9卷 836-838页

作者： Frauke Muecksch Oliver t.Fackler Department of Infectious Diseases Heidelberg UniversityMedical Faculty HeidelbergVirologyCenter for Integrative Infectious Disease Research(CIID)HeidelbergGermany Chica and Heinz Schaller(CHS)Research Group Department of Infectious DiseasesVirologyUniversity Hospital HeidelbergHeidelbergGermany Department of Infectious Diseases Heidelberg UniversityMedical Faculty HeidelbergIntegrative VirologyCenter for Integrative Infectious Disease Research(CIID)HeidelbergGermany German Centre for Infection Research(DZIF) Partner Site HeidelbergHeidelbergGermany

In a study recently published in Cell,Saunders et al.report that a new anti-HIV vaccine triggers antibody responses resembling CD4-binding site broadly neutralizing antibody precursors in rhesus macaques.1 this study provides important proof of concept and establishes a framework for the rational design of an effective HIV vaccine.

关键词： al. vaccine rational

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the bumpy road of purinergic inhibitors to clinical application in immune-mediated diseases

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Neural Regeneration Research 2024年第6期19卷 1206-1211页

作者： Matihias t.Wyss Christine Heuer Marina Herwerth Institute of Pharmacology and toxicology University of Zurich Neuroscience Center Zurich (ZNZ) University of Zurich and ETH Zurich 3. Neurology Department University Hospital of Zurich

Purinergic signaling plays important roles throughout the body in the regulation of organ functions during and following the disruption of homeostasis. this is also reflected by the widespread expression of two families of purinergic receptors(P1 and P2) with numerous subtypes. In the last few decades, there has been increasing evidence that purinergic signaling plays an important role in the regulation of immune functions. Mainly, signals mediated by P2 receptors have been shown to contribute to immune system-mediated pathologies. thus, interference with P2 receptors may be a promising strategy for the modulation of immune responses. Although only a few clinical studies have been conducted in isolated entities with limited success, preclinical work suggests that the use of P2 receptor inhibitors may bear some promise in various autoimmune diseases. Despite the association of P2 receptors with several disorders from this field, the use of P2 receptor antagonists in clinical therapy is still very scarce. In this narrative review, we briefly review the involvement of the purinergic system in immunological responses and clinical studies on the effect of purinergic inhibition on autoimmune processes. We then open the aperture a bit and show some preclinical studies demonstrating a potential effect of purinergic blockade on autoimmune events. Using suramin, a non-specific purinergic inhibitor, as an example, we further show that off-target effects could be responsible for observed effects in immunological settings, which may have interesting implications. Overall, we believe that it is worthwhile to further investigate this hitherto underexplored area.

关键词： autoimmune diseases neurological disorders purinergic system P2 receptor inhibitors suramin

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CompactChain:an efficient stateless chain for UtXO-model blockchain

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Frontiers of Computer Science 2024年第2期18卷 167-179页

作者： B Swaroopa REDDY t Uday Kiran REDDY Department of Electrical Engineering Indian Institute of Technology HyderabadHyderabadTelangana 502285India

In this work,we propose a stateless blockchain called CompactChain,which compacts the entire state of the UtXO(Unspent transaction Output)based blockchain systems into two RSA accumulators.the first accumulator is called transaction Output(tXO)commitment which represents the tXO set.the second one is called Spent transaction Output(StXO)commitment which represents the StXO set.In this work,we discuss three algorithms:(i)to update the tXO and StXO commitments by the miner.the miner also provides the proofs for the correctness of the updated commitments;(ii)to prove the transaction’s validity by providing a membership witness in tXO commitment and non-membership witness against StXO commitment for a coin being spent by a user;(iii)to update the witness for the coin that is not yet spent;the experimental results evaluate the performance of the CompactChain in terms of time taken by a miner to update the commitments and time taken by a validator to verify the commitments and validate the transactions.We compare the performance of CompactChain with the existing state-of-the-art works on stateless blockchains.CompactChain shows a reduction in commitments update complexity and transaction witness size which inturn reduces the mempool size and propagation latency without compromising the system throughput(transactions per second(tPS)).

关键词： stateless blockchain RSA Accumulator StXO commitment tXO commitment UtXO Non-interactive Proof of Exponentiation(NI-PoE) transactions per second(tPS)

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