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Numerical modelling of reinforced concrete flexural members strengthened using textile reinforced mortars

Frontiers of Structural and Civil Engineering 2023年第4期17卷 649-668页

作者： naveen Revanna Charles K.S.Moy Department of Civil Engineering Xi’an Jiaotong-Liverpool UniversitySuzhou 215123China

Externally bonded(EB)and near-surface mounted(NSM)bonding are two widely adopted and researched strengthening methods for reinforced-concrete *** composite substrates are easy to reach and repair using appropriate surface treatments,whereas NSM techniques can be easily applied to the soffit and concrete member *** EB bonded fiber-reinforced polymer(FRP)technique has a significant drawback:combustibility,which calls for external protective agents,and textile reinforced mortar(TRM),a class of EB composites that is noncombustible and provides a similar functionality to any EB FRP-strengthened *** study employs a finite element analysis technique to investigate the failing failure of carbon textile reinforced mortar(CTRM)-strengthened reinforced concrete *** principal objective of this numerical study was to develop a finite element model and validate a set of experimental data in existing literature.A set of seven beams was modelled and calibrated to obtain concrete damage plasticity(CDP)*** predicted results,which were in the form of load versus deflection,load versus rebar strain,tensile damage,and compressive damage patterns,were in good agreement with the experimental ***,a parametric study was conducted to verify the applicability of the numerical model and study various influencing factors such as the concrete strength,internal reinforcement,textile roving spacing,and externally-applied load *** ultimate load and deflection of the predicted finite element results had a coefficient of variation(COV)of 6.02%and 5.7%,respectively.A strain-based numerical comparison with known methods was then conducted to investigate the debonding *** developed finite element model can be applied and tailored further to explore similar TRM-strengthened beams undergoing debonding,and the preventive measures can be sought to avoid premature debonding.

关键词： fiber reinforced polymer textile reinforced mortar finite element analysis concrete damage plasticity calibration and validation parametric study

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Effect of different geometrical non-uniformities on nonlinear vibration of porous functionally graded skew plates: A finite element study

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Defence Technology（防务技术） 2022年第6期18卷 918-936页

作者： H.S.naveen Kumar Subhaschandra Kattimani Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkal575025India

This article presents the investigation of nonlinear vibration analysis of tapered porous functionally graded skew(TPFGS)plate considering the effects of geometrical non-uniformities to optimize the thickness in the structural *** TPFGS plate is analyzed considering linearly,bi-linearly,and exponentially varying *** plate’s effective material properties are tailor-made using a modified power-law distribution in which gradation varies along the thickness direction of the TPFGS *** the non-linear finite element formulation to develop the kinematic equation’s displacement model for the TPFGS plate is based on the first-order shear deformation theory(FSDT)in conjunction with von Karman’s *** nonlinear governing equations are established by Hamilton’s *** direct iterative method is adopted to solve the nonlinear mathematical relations to obtain the nonlinear *** influence of the porosity distributions and porosity parameter indices on the nonlinear frequency responses of the TPFGS plate for different skew angles and variable thicknesses are studied for various geometrical *** influence of taper ratio,variable thickness,skewness,porosity distributions,gradation,and boundary conditions on the plate’s nonlinear vibration is *** nonlinear frequency analysis reveals that the geometrical nonuniformities and porosities significantly influence the porous functionally graded plates with varying thickness than the uniform ***,exponentially and linearly variable thicknesses can be considered for the thickness optimizations of TPFGS plates in the structural design.

关键词： Functionally graded material Shear deformation theory Porosity distributions Variable thickness Geometrical skewness Nonlinear free vibration

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S-,N-and C-doped ZnO as semiconductor photocatalysts:A review

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Frontiers of Materials Science 2019年第1期13卷 1-22页

作者： Vijaya KUMARI Anuj mittal Jitender JINDAL Suprabha YADAV naveen KUMAR Department of Chemistry Maharshi Dayanand University RohtakIndia Department of Chemistry R.P.S.Degree CollegeMohindergarhIndia

In the past few decades,many novel non-metal doped ZnO materials have developed hasty interest due to their adaptable properties such as low recombination rate and high activity under the solar light *** this article,we compiled recent research advances in non-metal(S,N,C)doped ZnO,emphasizing on the related mechanism of catalysis and the effect of non-metals on structural,morphological,optical and photocatalytic characteristics of *** review will enhance the knowledge about the advancement in ZnO and will help in synthesizing new ZnO-based materials with modified structural and photocatalytic properties.

关键词： degradation recombination mechanism photocatalyst pollutant

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Synthesis and characterization of lanthanum-doped curcumin-functionalized antimicrobial copper oxide nanoparticles

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Journal of Rare Earths 2023年第10期41卷 1606-1615,I0005页

作者： Sai Varshith Chakka naveen Thanjavur Sunmi Lee Sanghyo Kim Department of Bionanotechnology Gachon UniversitySeongnam13120South Korea Department of Virology Sri Venkateswara UniversityTirupati517502India Department of K-beauty business Daegu Haany UniversityKyungsan42158South Korea

Flavonoid-based nanomaterials have extensive potential in antimicrobial research because of their non-toxicity,large-scale producibility,and chemical *** efficient combination of flavonoids and rare earth metals can have excellent antimicrobial properties owing to their robust medicinal and physicochemical *** this study,we synthesized copper oxide(CuO)nanoparticles(NPs)using a reflux reaction and repeated doping with the rare earth element lanthanum to prepare La-CuO ***,these La-CuO NPs were functionalized with the flavonoid curcumin,and the modified NPs were termed Cu-La-CuO *** NPs were chemically characterized via microscopic and spectroscopic techniques,including transmission electron microscopy(TEM),scanning electron microscopy(SEM),ultraviolet-visible(UV-Vis)adsorption,Fourier transform infrared spectroscopy(FT-IR)spectroscopy,and powder X-ray diffraction(XRD)*** SEM-EDX analysis reveals the elements doped into the native CuO *** TEM and XRD characterization results show,in detail,the distinct morphology and phase composition of the prepared CuO,La-CuO,and Cu-La-CuO *** antimicrobial activity of the Cu-La-CuO NPs was investigated on bacteria,such as Escherichia coli(***)and Bacillus subtilis(***),and fungi,including Aspergillus niger(A niger).The Cu-La-CuO NPs delivers excellent antimicrobial effects due to the incorporation of lanthanum and curcumin into the CuO *** Cu-La-CuO NPs show excellent antimicrobial potentials with an adequate zone of inhibition values around 2.2 and 2.9 mm in *** and ***,*** and dead analysis studies suggest the antimicrobial effects of lanthanum and curcumin moieties over native CuO *** obtained results are significant in developing of rare earth metal-based flavo no id-conjugated nanocomposites against typical microbes.

关键词： Copper oxide nanoparticles Reflux reaction Curcumin Antimicrobial activity Cu-La-CuO NPs Rare earths

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Computational Fluid Dynamics Study of a Compound Flow Field for Proton Exchange Membrane Fuel Cell(PEMFC) Performance Enhancement

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Journal of Thermal Science 2022年第6期31卷 2374-2384页

作者： Venkateswarlu VELISALA Gandhi PULLAGURA naveen Kumar CHINNAM Raju GANTA Automobile Engineering Section Damacharla Anjaneyulu Government PolytechnicOngole 523002Andhra PradeshIndia GITAM Institute of Technology Visakhapatnam 530045Andhra PradeshIndia Vishnu Institute of Technology Bhimavaram 534202Andhra PradeshIndia BVC Engineering College Odalarevu 533210Andhra PradeshIndia

The aim of the present work is to evaluate proton exchange membrane(PEM) fuel cell performance with a modified serpentine flow field with right angle turn by numerical modeling. A 3-D PEM fuel cell model of size 50 cm^(2) active area is developed. A conventional serpentine flow field is modified and the same is considered for the supply of reactants. Computational fluid dynamics(CFD) based simulations were conducted to analyse the pressure drop, distribution of reactants(H_(2) and O_(2)), liquid water activity, current flux density and water content in the membrane. From the simulation results, polarization curve is drawn to validate the literature data of PEMFC with the conventional serpentine flow field. Comparison of simulated polarization curve with literature data revealed that modified serpentine flow field performance is better than conventional serpentine flow field as it offers better water exclusion and uniform sharing of reactants. From this study, it is concluded that model of flow field pattern influences the functioning of fuel cell and utmost care must take while selecting a pattern for flow field of PEM fuel cell.

关键词： PEM fuel cell CFD current density water removal modified serpentine flow field membrane water content

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Luminescence Dating and Bracketing Time of the Youngest Toba Tuff Deposits in the Quaternary Sediments of Purna Alluvial Basin,Central India

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Journal of Earth Science 2022年第4期33卷 1007-1016页

作者： Singh Ajab K.Srivastava Ashok Chauhan naveen Department of Geology Faculty of ScienceUniversity of MalayaKuala Lumpur 50603Malaysia Department of Geology SGB Amravati UniversityAmravati 444602India Physical Research Laboratory Ahmedabad 380009India

Light gray to yellowish brown youngest Toba tuff(YTT)ash,preserved in the Quaternary sediments of India,have been used as a tool to know depositional and bracketing time period of the same in the sediments through applications of luminescence dating to interpret age connotation of various geological ***-and post-tephra sediments of YTT ash beds from Hudki and Sukali areas of Purna alluvial basin,Central India have been optically dated to interpret the depositional age and bracketing time of the tephra within sedimentary *** sediments are yellowish brown,thinly bedded,laminated,silty clay and host laterally extend discontinued beds of 0.15–0.20 m *** ash is light gray,fine grained and powdery in nature,massive to structureless and lacks any sign of retransportation and redeposition,hence,considered as primary in *** four sediment samples,one each from pre-and post-tephra lithounits of both the localities have been dated through optically stimulated luminescence technique(OSL)equipped with single aliquot regenerative(SAR)procedure on the feldspar *** shows pre-and post-tephra ages of 57±5 and 70±4 ka respectively for Hudki and 66±5 and 67±4 ka for Sukali *** depositional ages suggest that the ash was bracketed within sediments thousands years after YTT *** is correlatable with the previously reported depositional and absolute ages for the YTT ash from the localities of Ghoghara and Khuntheli,Son Valley;Tejpur,Madhumati River Basin and Jwalapuram,Jurreru *** ages also provide an idea about the period of existence of biological communities represented by the remains of faunal and vegetational activities before and during settlement of the YTT ash in the basin area.

关键词： youngest Toba tuff Tephra optically stimulated luminescence Quaternary sediments depositional age

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Co-Occurrence Histogram Based Ensemble of Classifiers for Classification of Cervical Cancer Cells

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Journal of Electronic Science and Technology 2022年第3期20卷 270-281页

作者： Rajesh Yakkundimath Varsha Jadhav Basavaraj Anami naveen Malvade the Department of Computer Science and Engineering Karnataka Lingayat Education Institute of TechnologyHubballi580027India Department of Information Science and Engineering Shri Dharmasthala Manjunatheshwara College of Engineering and TechnologyDharwad580008India the Department of Information Science and Engineering Smt.Kamala&Sri.Venkappa M.Agadi College of Engineering and TechnologyLakshmeshwar582116India the Visvesvaraya Technological University Belagavi590018India

To explore the potential of conventional image processing techniques in the classification of cervical cancer cells, in this work, a co-occurrence histogram method was employed for image feature extraction and an ensemble classifier was developed by combining the base classifiers, namely, the artificial neural network(ANN),random forest(RF), and support vector machine(SVM), for image classification. The segmented pap-smear cell image dataset was constructed by the k-means clustering technique and used to evaluate the performance of the ensemble classifier which was formed by the combination of above considered base classifiers. The result was also compared with that achieved by the individual base classifiers as well as that trained with color, texture, and shape features. The maximum average classification accuracy of 93.44% was obtained when the ensemble classifier was applied and trained with co-occurrence histogram features, which indicates that the ensemble classifier trained with co-occurrence histogram features is more suitable and advantageous for the classification of cervical cancer cells.

关键词： Cervical cancer co-occurrence histogram ensemble classification k-means clustering

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Data-driven Approach for State Prediction and Detection of False Data Injection Attacks in Smart Grid

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Journal of Modern Power Systems and Clean Energy 2023年第2期11卷 455-467页

作者： Haftu Tasew Reda Adnan Anwar Abdun Mahmood naveen Chilamkurti Department of Computer Science and IT La Trobe UniversityBundooraVIC 3086Australia School of IT Deakin UniversityWaurn PondsVIC 3216Australia

In a smart grid,state estimation(SE)is a very important component of energy management *** main functions include system SE and detection of cyber ***,it has been shown that conventional SE techniques are vulnerable to false data injection(FDI)attack,which is a sophisticated new class of attacks on data integrity in smart *** main contribution of this paper is to propose a new FDI attack detection technique using a new data-driven SE model,which is different from the traditional weighted least square based SE *** SE model has a number of unique advantages compared with traditional SE ***,the prediction technique can better maintain the inherent temporal correlations among consecutive measurement ***,the proposed SE model can learn the actual power system ***,this paper shows that this SE model can be effectively used to detect FDI attacks that otherwise remain stealthy to traditional SE-based bad data *** proposed FDI attack detection technique is evaluated on a number of standard bus *** performance of state prediction and the accuracy of FDI attack detection are benchmarked against the state-ofthe-art *** results show that the proposed FDI attack detection technique has a higher detection rate compared with the existing techniques while reducing the false alarms significantly.

关键词： Data-driven false data injection machine learning power system security state estimation smart grid

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Relative active tectonics evaluation using geomorphic and drainage indices, in Dadra and Nagar Haveli, western India

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Geodesy and Geodynamics 2022年第3期13卷 219-229页

作者： naveen Kumar Rakesh K.Dumka Kapil Mohan Sumer Chopra Institute of Seismological Research(ISR) RaysanGandhinagarGujaratIndia Department of Earth Science Gujarat UniversityNavrangpuraAhmedabad380009India

The present study area,Dadra and Nagar Haveli,contains several lineaments and traces of active *** various aspect of the geomo rphic analysis,i.e.,stream length(SL) gradient,hypsometric integral(HI),basin shape(BS),valley floor(VF),have been applied to evaluate the relative index of active tectonics(RIAT) of the Damanganga *** high and low zones of tectonic activity have been identified based on the geomorphic analysis of the *** evaluation of all indices,three classes,class IIhigh(1.3 ≤RIAT <1.5),class Ⅲ-moderate(1.5 ≤RIAT <1.8),and class Ⅳ-low(1.8 ≤RIAT),have been obtained to outline the degree/gradation of comparative tectonic activities in the study *** appraised outcome of the RIAT dispersal is also well reinforced by the geomorphic evidence in the *** collective outcomes of geomorphic evidence,such as stream deflection and analysis of lineament,deflection of streams,and geomorphic indices,conceal that the Damanganga watershed is affected by tectonic activity.

关键词： Active tectonics Geomorphic indices Relative index of active tectonics(RIAT) Drainage indices

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Is early patent ductus arteriosus ligation helpful in premature neonates? A 10-year retrospective study

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World Journal of Pediatrics 2022年第5期18卷 350-357页

作者： Anip Garg naveen Athiraman Elizabeth Jenkins David Crossland Prakash Kannan Loganathan Neonatal Unit Royal Victoria InfirmaryNewcastleUK Paediatric Cardiology Freeman HospitalNewcastleUK Neonatal Unit James Cook University HospitalMarton RoadMiddlesbrough TS43BWUK

Background To compare short and long outcomes between early(≤28 days)(EL)and late ligation(LL)*** explore factors predicting early extubation(≤7 days)after patent ductus arteriosus(PDA)*** We conducted a single center,retrospective cohort study of preterm infants<32 weeks who underwent surgical ligation over a 10-year period(2009-2019).Results A total of 133 infants underwent PDA ligation,in the study *** groups had similar short-term outcome such as bronchopulmonary dysplasia(BPD)or death(96%vs.98%,P=0.64)and long-term clinical outcomes including Bayley's assessment at 2 years corrected *** infants in the EL group developed severe BPD(63%vs.81%,P=0.02).Age at ligation had adjusted odds ratio of 1.04 with over lapping confidence interval(95%CI 1.0-1.1,P=0.02)for severe BPD/*** was no difference in day of extubation between the EL and LL group(8 days vs.7 days,P=0.85).Left atrium/aortic root ratio of ≥1.75 would give sensitivity of 41% and 80% specificity for early extubation(area under the curve of 0.61).There was marginal reduction of hospital stay in the EL group[113(105-121)days vs.115(107-123)days;log rank P=0.026].Conclusion EL can be delivered safely with a clinically important lower incidenee of severe BPD and shorter duration of hospital stay compared to LL.

关键词： Bronchopulmonary dysplasia Extubation Patent ductus arteriosus ligation

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