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Journal of Bionic Engineering 2019年第3期16卷 400-409页

作者： Srinadh Mattaparthi chandra shekhar sharma Creative & Advanced Research Based on Nanomaterials (CARBON) Laboratory Department of Chemical Engineerings Indian Institute of Technology Hyderabad Kandi Telangana 502285 India

In this work, we utilized underside of four different plant leaves with different scale of hierarchical surface roughness to fabricate large area self-cleaning antireflective polymer surfaces. A simple and precise two-step soft-lithography replica molding technique was deployed by using polydimethylsiloxane (PDMS) polymer as a replicating material. In the first step, a negative PDMS replica was fabricated by using the underside of an original leaf as a template material. In the second step, a positive PDMS replica was fabricated through a negative PDMS replica used as a template. In order to study the non-wetting and light trapping properties, as-replicated polymer surfaces were characterized using Scanning Electron Microscopy (SEM), contact angle goniometer, and UV-Vis spectroscopy. SEM images confirmed the successful replication of complex hierarchical structures while contact angle measurement studies established retaining high non-wetting properties in polymer replicas. Optical studies suggest near zero reflection in normal mode and less than 5% diffuse reflection when measured using integrated sphere mode. These results have been correlated and explained with the air-liquid fraction and roughness factor as measured using three-dimensional optical profilometer.

关键词： biomimicking natural leaf replica molding non-wetting light trapping hierarchical roughness

Model tests and numerical analyses on horizontal impedance functions of inclined single piles embedded in cohesionless soil

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Earthquake Engineering and Engineering Vibration 2013年第1期12卷 143-154页

作者： chandra shekhar Goit Masato Saitoh Department of Civil and Environmental Engineering Saitama University

Horizontal impedance functions of inclined single piles are measured experimentally for model soil-pile systems with both the effects of local soil nonlinearity and resonant *** practical pile inclinations of 5掳 and 10掳 in addition to a vertical pile embedded in cohesionless soil and subjected to lateral harmonic pile head loadings for a wide range of frequencies are *** obtained with low-to-high amplitude of lateral loadings on model soil-pile systems encased in a laminar shear box show that the local nonlinearities have a profound impact on the horizontal impedance functions of *** impedance functions of inclined piles are found to be smaller than the vertical pile and the values decrease as the angle of pile inclination *** values of horizontal impedance functions are obtained for the ＇positive＇ and ＇negative＇ cycles of harmonic loadings,leading to asymmetric force-displacement relationships for the inclined *** of these experimental results is carried out through three-dimensional nonlinear finite element analyses,and the results from the numerical models are in good agreement with the experimental *** analyses conducted on the numerical models suggest that the consideration of local nonlinearity at the vicinity of the soil-pile interface influence the response of the soil-pile systems.

关键词： inclined single piles harmonic loads horizontal impedance functions local nonlinearity finite element model

Identification and characterization of integron mediated antibiotic resistance in pentachlorophenol degrading bacterium isolated from the chemostat

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Journal of Environmental Sciences 2009年第6期21卷 858-864页

作者： sharma Ashwani THAKUR Indu shekhar Environmental Biotechnology Laboratory School of Environmental SciencesJawaharlal Nehru UniversityNew Mehrauli Road

A bacterial consortium was developed by continuous enrichment of microbial population isolated from sediment core of pulp and paper mill effluent in mineral salts medium（MSM） supplemented with pentachlorophenol（PCP） as sole source of carbon and energy in the *** consortia contained three bacterial *** were identified as Escherichia coli,Pseudomonas aeruginosa and Acinetobacter *** 16S rRNA gene sequence *** *** degraded PCP through the formation of tetrachloro-p-hydroquinone（TecH）,2-chloro-1,4-benzenediol and products of ortho ring cleavage detected by gas chromatograph/mass spectrometer（GC-MS）.Out of the three acclimated PCP degrading bacterial strains only one strain,Acinetobacter *** the presence of integron gene cassette as a marker of its stability and antibiotic *** strain possessed a 4.17 kb amplicon with 22 ORF＇*** plasmid isolated from the Acinetobacter *** subjected to shotgun cloning through restriction digestion by BamHI,HindIII and SalI,ligated to pUC19 vector and transformed into *** XLBlue1α,and finally selected on MSM containing PCP as sole source of carbon and energy with ampicillin as antibiotic *** sequence analysis of recombinant clones indicated homology with integron gene cassette and multiple antibiotic resistance genes.

关键词： Acinetobacter sp. antibiotic resistance gene chemostat integron gene cassette pentachlorophenol recombinant clone

Finite Capacity Service System with Partial Server Breakdown and Recovery Policy:An Economic Perspective

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Journal of Systems Science and Systems Engineering 2024年第6期33卷 651-681页

作者： Shreekant Varshney Suman Kaswan Mahendra Devanda chandra shekhar Department of Mathematics School of TechnologyPandit Deendayal Energy UniversityGandhinagarGujarat382426India Department of Mathematics Birla Institute of Technology and Science PilaniPilani CampusPilaniRajasthan333031India Department of Mathematics Maharaja Surajmal Brij UniversityBharatpurRajasthan321201India

Developing a comprehensive service strategy to optimize customer satisfaction presents an ongoing challenge for effective facility *** essence of comprehensive systems is selecting the suitable service design,establishing an effective service delivery process,and building continuous *** research analyzes a finite capacity service system incorporating several realistic customer-server dynamics:customer impatience,server’s partial breakdown,and threshold recovery *** the number of customers is more,the server is under pressure to increase the service rate to mitigate the service system’s *** from this fact,the concept of service pressure condition is also *** characterization,we evaluate state probabilities derived using the matrix-analytic method and henceforth several performance *** address the cost optimization problem involving the developed Chapman-Kolmogorov forward differential-difference equations and determine optimal operational parameters,we employ the recently devised cuckoo search(CS)optimization approach.A comparative analysis is performed with the semi-classical optimizer:quasi-Newton(QN)method,and metaheuristics technique:particle swarm optimization(PSO),to validate the efficacy of ***,several numerical illustrations are depicted in different tables and graphs to understand essential characteristics quickly.

关键词： Customer impatience service pressure condition partial server breakdown threshold-based recovery policy Cuckoo search particle swarm optimization quasi-Newton

Vertical impedance functions of pile groups under low-to-high loading amplitudes:numerical simulations and experimental validation

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Earthquake Engineering and Engineering Vibration 2023年第3期22卷 647-666页

作者： Usama Zafar chandra shekhar Goit Masato Saitoh Riku Fukuda School of Science and Engineering Saitama University255 Shimo-OkuboSaitamaJapan

Piles in a group experience additional displacements in soil due to pile-to-pile interactions apart from those resulting from the external *** effect of these interactions determined assuming soil as an elastic and/or viscoelastic material on pile head impedance functions of the pile group is studied by relating the group stiffness to the static stiffness of a single ***,the prevailing elastic solutions may misestimate the resulting pile group response due to the lack of consideration for either soil(material)and/or soil-pile interface *** is well established that soil behaves nonlinearly under moderate-to-high loading amplitudes,and besides,the soil-pile interface nonlinearity can exist even at small loading *** study addresses the effects of these nonlinearities on the vertical impedance functions of a 3×3-pile group using numerical methods by direct analyses and superposition using pile-to-pile interaction *** numerical results are validated using scaled model tests under 1 g *** results highlight the overestimation of pile-to-pile interactions in the pile group when assuming elastic soil *** cases either by direct analyses or superposition approach involving soil and soil-pile interface nonlinearities agree well with the experimental pile group responses under close-to-elastic and nonlinear conditions.

关键词： impedance functions numerical simulations model-scale experiment superposition approach soil-pile interface nonlinearity

Ethanol steam reforming study over ZSM-5 supported cobalt versus nickel catalyst for renewable hydrogen generation

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Chinese Journal of Chemical Engineering 2019年第3期27卷 677-684页

作者： Ashutosh Kumar Ram Prasad Yogesh chandra sharma Department of Chemistry Indian Institute of Technology (Banaras Hindu University) Varanasi Department of Chemical Engineering & Technology Indian Institute of Technology (Banaras Hindu University) Varanasi

The renewable hydrogen generation through ethanol steam reforming is one of the anticipated areas for sustainable hydrogen generation. To elucidate the role of Ni and Co with ZSM-5 support, catalysts were prepared by wet impregnation method and ethanol steam reforming(ESR) was performed. The catalysts were characterized by HR-XRD, ATR–FTIR, HR-SEM, TEM with SAED, EDAX, surface area analyzer and TPR. It had shown complete ethanol conversion at 773 K, but the selectivity in hydrogen generation was found higher for 10% Ni/ZSM-5 catalyst as compared to 10% Co/ZSM-5. The 10% Ni/ZSM-5 catalyst has about 72% hydrogen selectivity at temperature 873 K. It indicates that Ni is a more sustainable catalyst as compared to Co with ZSM-5 support for ESR. The C_2H_4 was found major undesirable products up to 823 K temperature. Nevertheless, the 10% Ni/ZSM-5 catalyst had shown its stability for high temperature(873 K) ESR performance.

关键词： Ethanol steam reforming Zeolite Hydrogen Renewable energy Catalyst

Some Observations about the MOLSCAT

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Communications in Theoretical Physics 2015年第12期64卷 731-734页

作者： Mohit Kumar sharma Monika sharma Suresh chandra School of Studies in Physics Jiwaji University Physics Department Lovely Professional University

For calculation of cross sections for collisional transitions between rotational levels in a molecule,a computer code,MOLSCAT is *** the transitions between rotational levels in H_2 CS due to collisions with He atom,we have calculated cross sections under the CS approximation,for example,for total energy 11 cm^(-1).The calculations have been done for the single energy 11 cm"1 and for ten *** have found that the cross sections for the single energy 11 cm^(-1),differ from those in the first seven combinations,but are in agreement with those in the last three *** reason for the difference in the results appears that the MOLSCAT uses the intermediate data of calculations for one energy,in the calculations for other *** agreement with the last three combinations may be understood that when the energy of combination is in the decreasing trend,the cross sections for the first(common)energy are *** may be suggested to run the MOLSCAT for a single energy at a time.

关键词： ISM: molecules collisional transitions MOLSCAT

Exploring the potential of artificial intelligence techniques in prediction of the removal efficiency of vortex tube silt ejector

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International Journal of Sediment Research 2023年第4期38卷 615-627页

作者： Sanjeev Kumar chandra shekhar Prasad Ojha Nand Kumar Tiwari Subodh Ranjan Department of Civil Engineering Indian Institute of Technology Department of Civil Engineering National Institute of Technology

A vortex tube silt ejector is a curative hydraulic structure used to remove sediment deposits from canals and is recognized as one of the most efficient substitutes for physically removing canal sediment. The spatially varied flow in the channel and the rotational flow behavior in the tube make the silt removal process complex. It is even harder to accurately predict the silt removal efficiency by traditional models accurately. However, artificial intelligence(AI) and machine learning approaches have emerged as robust substitutes for studying complex processes. Therefore, this research makes use of AI approaches; support vector machine(SVM), random forest(RF), random tree(RT), and multivariate adaptive regression spline(MARS) to compute the vortex tube silt ejection efficiency using the laboratory data sets. The outcomes of the artificial intelligence(AI)-based techniques also were compared with traditional models. It was found that the RT model(root mean square error, RMSE = 2.165, Nash Sutcliffe efficiency, NSE = 0.98) outperforms the other applied approaches which had relatively more significant result errors. The sensitivity analysis of the process depicts the extraction ratio as the key parameter in the computation of vortex tube silt ejector removal efficiency. The findings of the AI-based approaches discussed in the current study might be helpful for hydraulic engineers as well as researchers in the assessment of the removal efficiency of vortex tube silt ejectors.

关键词： Vortex tube silt ejector Support vector machine Random forest Random tree Multivariate adaptive regression spline

Wind pollination in Pinus roxburghii

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Progress in Natural Science:Materials International 2007年第1期17卷 32-38页

作者： Vinod Prasad KHANDURI chandra Mohan sharma Department of Forestry Mizoram University Aizawl(Mizoram)India Department of Forestry HNB Garhwal University Srinagar Garhwal-246 174(Uttaranchal)India

Stigmatic pollen load and pollen concentration in the air were studied in the natural population of Pinus roxburghii at Ashtavakra (900 m asl), in the Pauri forest division of Garhwal Himalaya, India. The results reflect diurnal pollen occurrence in P. roxburghii , with the strong significant correlations between pollen concentrations in the air and wind speed, air temperature and relative air humidity. A significant correlation was also observed between microsporangium dehiscence and pollen occurrence in the air. The maximum concentration of pollen grains in the air and higher rates of pollen deposition onto the megasporophylls were between 12 pm and 16 pm of the day, which conforms the best time for pollination in a day in P. roxburghii. The receptivity of Ovulate strobili varied from 3 to 5 days, however, the bagged strobili remained receptive up to 6 days.

关键词： ovulate strobili pollen cones pollination receptivity wind speed P. roxburghii.

MOLECULAR DYNAMICS SIMULATION OF POLYMER/CARBON NANOTUBE COMPOSITES

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Acta Mechanica Solida Sinica 2015年第4期28卷 409-419页

作者： Sumit sharma Rakesh chandra Pramod Kumar Navin Kumar Department of Mechanical Engineering Dr.B.R.Ambedkar National Institute of Technology School of Mechanical Materials & Energy Engineering (SMMEE) Indian Institute of Technology

In this paper, we present classical molecular dynamics （MD） simulations of model polymer/CNT composites constructed by embedding a single wall （10,10） CNT into two different amorphous polymer matrices： poly（methyl methacrylate） and poly{（m-phenylene-vinylene）-co- [（2,5-dioctoxy-p-phenylene） vinylene]}, respectively, with different volume fractions. The simulation results support the idea that it is possible to use CNTs to mechanically reinforce an appropri- ate polymer matrix, especially in the longitudinal direction of the nanotube. The comparison of the simulation results with the macroscopic rule-of-mixtures for composite systems showed that for strong interfacial interactions, there can be large deviations of the results from the rule-of- mixtures. In order to verify this study, results obtained have been compared with those given by Elliott and Han （2007）.

关键词： nano-structures elasticity mechanical properties computational modeling