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Vibration and buckling analyses of nanobeams embedded in an elastic medium

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Chinese Physics B 2015年第9期24卷 489-496页

作者： S Chakraverty Laxmi behera Department of Mathematics National Institute of Technology Rourkela

Boundary characteristic orthogonal polynomials are used as shape functions in the Rayleigh–Ritz method to investigate vibration and buckling of nanobeams embedded in an elastic medium. The present formulation is based on the nonlocal Euler–Bernoulli beam theory. The eigen value equation is developed for the buckling and vibration analyses. The orthogonal property of these polynomials makes the computation easier with less computational effort. It is observed that the frequency and critical buckling load parameters are dependent on the temperature, elastic medium, small scale coefficient,and length-to-diameter ratio. These observations are useful in the mechanical design of devices that use carbon nanotubes.

关键词： Rayleigh–Ritz method boundary characteristic orthogonal polynomials nonlocal elasticity theory Euler–Bernoulli beam theory

Synthesis and Characterization of ZnO Nanowires and ZnO–CuO Nanoflakes from Sputter-Deposited Brass(Cu_(0.65)–Zn_(0.35)) Film and Their Application in Gas Sensing

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Journal of Materials Science & Technology 2015年第11期31卷 1069-1078页

作者： Bhagaban behera Sudhir Chandra Centre for Applied Research in Electronics Indian Institute of Technology Delhi

A novel method was presented for synthesis of ZnO and ZnO-CuO composites in the form of nanowires, nanorods and nanoflakes on oxidized silicon substrates. Further, the use of the synthesized nanostructures for gas sensing was demonstrated. Pure brass （Cu0.65-Zn0.35） films were deposited on oxidized Si substrate by radio frequency （RF） diode sputtering. Subsequently, these films having thickness in the range of 100-200 nm were oxidized in different oxidizing ambient in the temperature range of 300-550 ℃. The effect of temperature, time and oxidizing ambient on the growth of nanostructures was investigated by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and photoluminescence （PL） techniques. The nanostructures surface was analyzed by X-ray photoelectron spectroscopy （XPS）. The synthesized nanowires had diameter in the range of 60-100 nm and length up to 50 μm. Based on these observations, the growth mechanism has been suggested. For the nanorods, the diameter was observed to be -150 nm. Samples having dense nanowires, nanorods and nanoflakes were used as a gas sensing material. The performance Of the sensor was investigated for different nanostructured materials for various volatile organic compounds （VOCs）, It was observed that ZnO- CuO nanoflakes were more sensitive to VOC sensing compared to ZnO nanowires and nanorods.

关键词： Brass Thermal oxidation Nanostructures ZnO CuO sensor Sensor Volatile organic compounds (VOCs)

Buckling analysis of nanobeams with exponentially varying stiffness by differential quadrature method

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Chinese Physics B 2017年第7期26卷 218-227页

作者： S Chakraverty Laxmi behera Department of Mathematics National Institute of Technology Rourkela

We present the application of differential quadrature（DQ） method for the buckling analysis of nanobeams with exponentially varying stiffness based on four different beam theories of Euler-Bernoulli, Timoshenko, Reddy, and *** formulation is based on the nonlocal elasticity theory of Eringen. New results are presented for the guided and simply supported guided boundary conditions. Numerical results are obtained to investigate the effects of the nonlocal parameter,length-to-height ratio, boundary condition, and nonuniform parameter on the critical buckling load parameter. It is observed that the critical buckling load decreases with increase in the nonlocal parameter while the critical buckling load parameter increases with increase in the length-to-height ratio.

关键词： differential quadrature method exponentially varying stiffness different beam theories

Structural, dielectric, and electrical properties of lithium niobate microfibers

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Journal of Advanced Ceramics 2016年第1期5卷 84-92页

作者： Cícero Rafael CENA Ajay Kumar behera Banarji behera UFMS-Federal University of Mato Grosso do Sul CP.549 79070-900 Campo Grande-MS Brazil School of Physics Sambalpur University Jyoti Vihar Burla-7 68019 Odisha India

Lithium niobate (LiNbO3) fibers, obtained from the heat treatment of composite fibers (polymer/inorganic precursors), were successfully prepared by using the blow-spinning technique. A chemical solution containing Li and Nb ions, added to poly(vinyl pyrrolidone) solution, was used as precursor solution. The best condition for producing composite fibers was determined. The morphology of green and crystallized fibers was characterized by scanning electron microscopy (SEM) and revealed fibrous structure with an average diameter around 800 nm. X-ray diffraction (XRD) measurement revealed a pure LiNbO3 (LN) phase formation. Detailed studies of dielectric response at various frequencies and temperatures exhibited a dielectric anomaly at 364 ℃. The electrical properties (impedance, modulus, and conductivity) of the fibers were studied using impedance spectroscopy technique. The contributions of grain and grain boundary effects were observed in the LN fibers. The activation energy of the composite fibers was found to be 1.5 eV in the high temperature region (325-400 ℃).

关键词： ceramics fibers composites chemical synthesis impedance spectroscopy dielectric properties

Robust Adaptive Gain Higher Order Sliding Mode Observer Based Control-constrained Nonlinear Model Predictive Control for Spacecraft Formation Flying

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IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 367-381页

作者： Ranjith Ravindranathan Nair Laxmidhar behera Department of Electrical Engineering Indian Institute of TechnologyKanpur Kanpur-208 016India IEEE

This work deals with the development of a decentralized optimal control algorithm, along with a robust observer,for the relative motion control of spacecraft in leader-follower based formation. An adaptive gain higher order sliding mode observer has been proposed to estimate the velocity as well as unmeasured disturbances from the noisy position measurements.A differentiator structure containing the Lipschitz constant and Lebesgue measurable control input, is utilized for obtaining the estimates. Adaptive tuning algorithms are derived based on Lyapunov stability theory, for updating the observer gains,which will give enough flexibility in the choice of initial ***, it may help to cope with unexpected state jerks. The trajectory tracking problem is formulated as a finite horizon optimal control problem, which is solved online. The control constraints are incorporated by using a nonquadratic performance functional. An adaptive update law has been derived for tuning the step size in the optimization algorithm, which may help to improve the convergence speed. Moreover, it is an attractive alternative to the heuristic choice of step size for diverse operating conditions. The disturbance as well as state estimates from the higher order sliding mode observer are utilized by the plant output prediction model, which will improve the overall performance of the controller. The nonlinear dynamics defined in leader fixed Euler-Hill frame has been considered for the present work and the reference trajectories are generated using Hill-Clohessy-Wiltshire equations of unperturbed motion. The simulation results based on rigorous perturbation analysis are presented to confirm the robustness of the proposed approach.

关键词： Adaptive gain higher order sliding mode observer leader-follower formation nonlinear model predictive control spacecraft formation flying tracking control

EMD-Att-LSTM: A Data-driven Strategy Combined with Deep Learning for Short-term Load Forecasting

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Journal of Modern Power Systems and Clean Energy 2022年第5期10卷 1229-1240页

作者： Neeraj Jimson Mathew Ranjan Kumar behera Indian Instituteof Technology Patna801103India

Electric load forecasting is an efficient tool for system planning, and consequently, building sustainable power systems. However, achieving desirable performance is difficult owing to the irregular, nonstationary, nonlinear, and noisy nature of the observed data. Therefore, a new attention-based encoderdecoder model is proposed, called empirical mode decomposition-attention-long short-term memory(EMD-Att-LSTM).EMD is a data-driven technique used for the decomposition of complex series into subsequent simpler series. It explores the inherent properties of data to obtain the components such as trend and seasonality. Neural network architecture driven by deep learning uses the idea of a fine-grained attention mechanism, that is, considering the hidden state instead of the hidden state vectors, which can help reflect the significance and contributions of each hidden state dimension. In addition, it is useful for locating and concentrating the relevant temporary data,leading to a distinctly interpretable network. To evaluate the proposed model, we use the repository dataset of Australian energy market operator(AEMO). The proposed architecture provides superior empirical results compared with other advanced models. It is explored using the indices of root mean square error(RMSE) and mean absolute percentage error(MAPE).

关键词： Short-term load forecasting Australian energy market operator long short-term memory(LSTM) empirical mode decomposition(EMD) attention mechanism

Response Analysis of Tension-Based Tension Leg Platform Under Irregular Waves

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China Ocean Engineering 2016年第4期30卷 603-614页

作者： D.S.bhaskara Rao R.Panneer Selvam Department of Ocean Engineering Indian Institute of Technology Madras

Tension Leg Platform（TLP） is a hybrid structure used as oil drilling and production facility within water depths of 1200 m. The extension of this TLP concept to deeper waters is a challenge and warrants for some innovative design concepts. In this paper, a relatively new concept of TLP which is christened as Tension-Based Tension Leg Platform（TBTLP） and patented by Srinivasan（1998） has been chosen for study. Response analysis of TLP with one tension base under irregular waves for three different sea states has been performed using hydrodynamic tool ANSYS？ AQWA？. Results are reported in terms of RAOs, response spectrums for surge, heave and pitch degrees of freedom from which spectral statistics have been obtained. The statistics of TBTLP have been compared with TLPs（without tension base） for two different water depths to highlight the features of the new concept. The effect of viscous damping and loading effects on the RAOs are also investigated.

关键词： Tension-Based Tension Leg Platform irregular waves time domain response response amplitudeoperators spectrum statistics coupled analysis

Transient parameter analysis of pneumatic conveying of fine particles for predicting the change of mode of flow

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Particuology 2017年第3期15卷 82-88页

作者： Shijo J.S. Niranjana behera School of Mechanical & Building Sciences VIT University Vellore Tamilnadu 632014 India

During the process of pneumatic conveying of fine particles, the flow mode may change from dense to dilute. In studying this mode change, we evaluate three parameters （Hurst exponent, Shannon entropy, and phase-space attractor size） used in signal analysis. Experimental data of pneumatic conveying of fly ash at three locations along a 173-m-long pipeline were used for this analysis. Variations in magnitude of the Hurst exponent, Shannon entropy, and size of the phase space attractor exhibit different trends in their variations for dense and dilute mode of flow. From these trends it is possible to predict the change from dense to dilute mode and the location along the length of the pipeline of this change in mode of flow.

关键词： Fluidized denseHurst exponent Shannon entropy Phase space

Germplasm Resources,Genes and Perspective for Aromatic Rice

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Rice science 2023年第4期30卷 294-305页

作者： Prafulla Kumar behera Debabrata PANDA Department of Biodiversity and Conservation of Natural Resources Central University of OdishaKoraput 764003OdishaIndia

Aromatic rice is considered an important commodity in the global market because of its strong aroma and eating and cooking *** countries,such as India and Pakistan,are the leading traders of Basmati rice,whereas Thailand is the major supplier of Jasmine rice in the international *** strong aroma of rice is associated with more than 300 volatile compounds,among which 2-acetyl-1-pyrroline(2-AP)is the principal component.2-AP is a phenotypic expression of spontaneous mutations in the recessive gene OsBadh2 or *** present review focuses on the origin,evolution and diversity of genetic resources of aromatic rice available worldwide.A brief discussion is presented on the genes responsible for quality traits along with details of their molecular *** compilation and discussion will be useful for future breeding programs and the biofortification of quality traits of aromatic rice to ensure food security and nutritional need.

关键词： aromatic rice 2-acetyl-1-pyrroline polyamine degradation pathway quality trait