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Rice science 2013年第6期20卷 415-426页

作者： P.MANIMARAN g.ravi kumar M.RAgHURAMI REDDY S.JAIN T.BHASKAR RAO S.K.MANgRAUTHIA R.M.SUNDARAM S.raviCHANDRAN S.M.BALACHANDRAN Biotechnology Laboratory Crop Improvement SectionDirectorate of Rice ResearchRajendranagarHyderabad 500030India

A rapid and reproducible method to develop transgenic plants with enhanced transformation efficiency using Agrobacterium has been developed for the elite indica rice variety BPT 5204. Different rice calli aged from 3 to 30 d were co-cultivated with pre-incubated Agrobacterium suspension culture （LBA4404： pSB1, pCAMBIA1301） and incubated in dark for 3 d. Based on the transient gUS gene expression analysis, 6-day-old young calli showed high transformation frequency followed by 21-day-old ones. Thus, both 6-and 21-day-old calli were used for assessing the stable transformation efficiency. It was observed that the 6-day-old young transformed calli showed about 2-fold higher regeneration frequency when compared with 21-day-old calli. The transformation efficiency was enhanced for young calli to 5.9% compared with 0.8% of the 21-day-old calli. Molecular and genetic analysis of transgenic plants （To） revealed the presence of 1-2 copies of T-DNA integration in transformants and it follows Mendalian ratio in T1 transgenic plants. From the present study, it was concluded that the development of transgenic rice plants in less duration with high regeneration and transformation efficiency was achieved in BPT 5204 by using 6-day-old young calli as explants.

关键词： Agrobacterium-mediated transformation meihod rice callus transformation transgenicplant indica rice

Opportunistic Routing with Multi-Channel Cooperative Neighbour Discovery

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Intelligent Automation & Soft Computing 2023年第2期35卷 2367-2382页

作者： S.Sathish kumar g.ravi AVS College of Technology Salem636106India Sona College of Technology Salem636005India

Due to the scattered nature of the network,data transmission in a dis-tributed Mobile Ad-hoc Network(MANET)consumes more energy resources(ER)than in a centralized network,resulting in a shorter network lifespan(NL).As a result,we build an Enhanced Opportunistic Routing(EORP)protocol architecture in order to address the issues raised *** proposed routing protocol goal is to manage the routing cost by employing power,load,and delay to manage the routing energy consumption based on theﬂooding of control pack-ets from the target *** to the goal of the proposed protocol techni-que,it is possible to manage the routing cost by applying power,load,and *** proposed technique also manage the routing energy consumption based on theﬂooding of control packets from the destination node in order to reduce the routing *** packet exchange between the target and all the nodes,on the other hand,is capable of having an inﬂuence on the overall efﬁciency of the *** EORP protocol and the Multi-channel Cooperative Neighbour Discovery(MCCND)protocol have been designed to detect the cooperative adja-cent nodes for each node in the routing route as part of the routing path discovery process,which occurs during control packet *** control packet transmission is taking place during the routing path discovery process,the EORP protocol and the Multi-channel Cooperative Neighbour Discovery(MCCND)protocol have been designed to detect the cooperative adjacent nodes for each node in the *** included is a simulation of these protocols in order to evaluate their performance across a wide range of packet speeds using Constant Bit Rate(CBR).When the packet rate of the CBR is 20 packets per second,the results reveal that the EORP-MCCND is 0.6 s quicker than the state-of-the-art protocols,according to theﬁ*** that the CBR packet rate is 20 packets per second,the EORP-MCCND achieves 0.6 s of End 2 End Delay,0.05 s of Routing Overhea

关键词： Macro-addressable network power-and load-aware routing deterministic and opportunistic routing gradient routing multi-channel cooperative neighbor discovery

Metathesis synthesis, characterization, spectral and photoactivity studies of Ln_(2/3)MoO_4(Ln=La, Pr, Nd, Sm, Eu, gd, Tb, Dy, Er and Y)

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Journal of Rare Earths 2015年第8期33卷 837-845页

作者： Radha Velchuri Suresh Palla g.ravi Naveen kumar Veldurthi J.R.Reddy M.Vithal Department of Chemistry Osmania University

Rare earth ortho-oxomolybdates of composition Ln2/aMoO4 （Ln=La, Pr, Nd, Sm, Eu, gd, Tb, Dy, Er and Y） were prepared by metathesis reaction. All these materials were characterized by powder X-ray diffraction, Fourier transform-infrared spectroscopy （FT-IR） and UV-Vis diffuse reflectance spectra. The Rietveld analysis of all the samples was carried out to obtain the unit cell parameters and reliability factors. All the materials were crystallized in tetragonal lattice with I41/a space group. The infrared spectra of all the samples were characterized by bands due to MoO42 units. The bandgap energies of all the samples were obtained from UV-Vis DRS spectra. The luminescence spectra of Ln2/3MoO4 （Ln=Pr, Eu and Dy） showed characteristic transitions of the rare earth ions. The visible light photocatalytic activity of all the samples was studied against degradation of methylene blue.

关键词： metathesis X-ray diffxaction IR spectroscopy UV-Vis spectroscopy photodegradation rare earths

Effect of gallium, aluminium, and chromium on silica supported V-Mg-O catalysts during oxidative dehydrogenation of propane: Kinetic study

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Journal of Natural gas Chemistry 2008年第3期17卷 256-263页

作者： B.ravi kumar Rajeev kumar Department of Chemical Engineering Indian Institute of Technology

The oxidative dehydrogenation （ODH） of propane was conducted on gallium, aluminum, and chromium doped Si30VMgO catalysts. On doping, the concentrations of the phases responsible for the activity and selectivity increased in their concentrations. The reaction studies were conducted in a tubular steel reactor at temperatures of 753, 783, 813, and 843 K and atmospheric pressure. The total flow rates of the feed were chosen as 30, 40, 50, and 60 ml/min. The propane to oxygen ratios were chosen at 1 ： 1, 2 ： 1, and 3 ： 1, respectively. The effect of various dopants on the activity and selectivity of the catalysts was studied. Deactivation studies were conducted over all the catalysts. The kinetic data were analyzed in terms of power law models and Langmuir-Hinshelwood （LH） models. The kinetic data results were analyzed by comparing the effect of dopants. Statistical model discrimination was done for the proposed models. AIC and BIC criteria were used for discrimination of the models.

关键词： oxidative dehydrogenation propane gallium aluminum chromium kinetic

Sand-polished Kapton film and aluminum as source of electron transfer triboelectric nanogenerator through vertical contact separation mode

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International Journal of Smart and Nano Materials 2020年第1期11卷 38-46页

作者： ravi kumar Cheedarala Jung Il Song Research Institute of Mechatronics Department of Mechanical EngineeringChangwon National UniversityUichang-guChangwon CityS.Korea

Contact electrification is a direct triboelectrification method for producing current through charge transfer when two different differentiated materials have brought into *** the first time,we developed a simple triboelectric nanogenerator(TENg)where the electronic charges were realized through contact separation mode between sand-polished Kapton(SPK)and Al ***,we demonstrated the energetic interfacial contact between these surfaces and observed satisfactory output *** novel SPK-TENg produced 40 V and 2.8μA,of open-circuit voltages(V_(oc))and short-circuit currents(Isc)at 4 Hz,***,the SPK-TENg was dramatically increased up the performance of TENg,up to 40% of V_(oc) and 42% of I_(sc),with respect to the Kapton film because the mobility of electrons is very high on the device surface compared to the other pristine Kapton *** fabricated SPK-TENgs were good candidates for satisfying the need for alternative contact separation mode TENgs.

关键词： Kapton contactelectrification K-Al TENg SPK-Al TENgs electron transfer mechanism

Near Optimal PID Controllers for the Biped Robot While Walking on Uneven Terrains

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International Journal of Automation and computing 2018年第6期15卷 689-706页

作者： ravi kumar Mandava Pandu Ranga Vundavilli School of Mechanical Sciences Indian Institute of Technology (IIT) Bhubaneswar

The execution of the gaits generated with the help of a gait planner is a crucial task in biped locomotion. This task is to be achieved with the help of a suitable torque based controller to ensure smooth walk of the biped robot. It is important to note that the success of the developed proportion integration differentiation （PID） controller depends on the selected gains of the controller. In the present study, an attempt is made to tune the gains of the PID controller for the biped robot ascending and descending the stair case and sloping surface with the help of two non-traditional optimization algorithms, namely modified chaotic invasive weed optimization （MCIWO） and particle swarm optimization （PSO） algorithms. Once the optimal PID controllers are developed, a simulation study has been conducted in computer for obtaining the optimal tuning parameters of the controller of the biped robot. Finally, the optimal gait angles obtained by using the best controller are fed to the real biped robot and found that the biped robot has successfully negotiated the said terrains.

关键词： Biped robot staircase sloping surface proportion integration differentiation (PID) controller modified chaotic invasive weed optimization (MCIWO) & particle swarm optimization (PSO) algorithm.

Processing and characterization of polymer precursor derived silicon oxycarbide ceramic foams and compacts

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Journal of Advanced Ceramics 2013年第4期2卷 318-324页

作者： Srinivasan NEDUNCHEZHIAN ravindran SUJITH ravi kumar Materials Processing Section Department of Metallurgical and Materials EngineeringIndian Institute of Technology MadrasChennai 600036Tamil NaduIndia

This work focused on the fabrication of silicon oxycarbide ceramic(SiOC)foams as well as dense compacts using poly(hydridomethylsiloxane)(PHMS)as a polymer *** room-temperature cross-linking of PHMS was achieved by the addition of 1,4-diazabicyclo[2.2.2]octane(DABCO)with the release of hydrogen gas as a *** resulted in self-blowing of the polymer precursor at room temperature and thereby offered the possibility of producing SiOC foams without the need of any external blowing *** also reported the fabrication of crack-free silicon oxycarbide compacts by cold compaction and pyrolysis route using polyvinyl alcohol(PVA)as a processing ***-shaped pellets were pyrolysed at 1300℃in argon atmosphere with a ceramic yield of approximately 85%.Increased resistance to phase separation and crystallization up to 1400℃was attributed to the presence of large volume fraction of free carbon in the material which was confirmed by Raman spectroscopy.

关键词： silicon oxycarbide foams 1,4-diazabicyclo[2.2.2]octane(DABCO) self-blown polymer poly(hydridomethylsiloxane)(PHMS)

Wide-Angle Scanning Antennas for Millimeter-Wave 5g Applications

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Engineering 2022年第4期8卷 60-71页

作者： Raj Mittra Abdelkhalek Nasri ravi kumar Arya Electrical and Computer Engineering University of Central FloridaOrlandoFL 32816USA Electrical and Computer Engineering Department Faculty of EngineeringKing Abdulaziz UniversityJeddah 21589Saudi Arabia Department of Electronics and Communication Engineering National Institute of Technology DelhiDelhi 110040India

The fifth generation(5g)network communication systems operate in the millimeter waves and are expected to provide a much higher data rate in the multi-gigabit range,which is impossible to achieve using current wireless services,including the sub-6 gHz *** this work,we briefly review several existing designs of millimeter-wave phased arrays for 5g applications,beginning with the low-profile antenna array designs that either are fixed beam or scan the beam only in one *** then move on to array systems that offer two-dimensional(2D)scan capability,which is highly desirable for a majority of 5g ***,in the main body of the paper,we discuss two different strategies for designing scanning arrays,both of which circumvent the use of conventional phase shifters to achieve beam *** note that it is highly desirable to search for alternatives to conventional phase shifters in the millimeter-wave range because legacy phase shifters are both lossy and costly;furthermore,alternatives such as active phase shifters,which include radio frequency amplifiers,are both expensive and *** this backdrop,we propose two different antenna systems with potential for the desired 2D scan performance in the millimeter-wave *** first of these is a Luneburg lens,which is excited either by a 2D waveguide array or by a microstrip patch antenna array to realize 2D scan ***,for second design,we turn to phased-array designs in which the conventional phase shifter is replaced by switchable PIN diodes or varactor diodes,inserted between radiating slots in a waveguide to provide the desired phase shifts for ***,we discuss several approaches to enhance the gain of the array by modifying the conventional array *** describe novel techniques for realizing both one-dimensional(1D)and 2D scans by using a reconfigurable metasurface type of panels.

关键词： Luneburg lens Scanning arrays Millimeter-wave antennas Switchable phase shifters Reconfigurable metasurfaces

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Journal of Ocean Engineering and Science 2023年第2期8卷 111-123页

作者： Raj kumar ravi Shankar Verma Atul kumar Tiwari Department of Mathematics Faculty of Engineering&TechnologyVeer Bahadur Singh Purvanchal UniversityJaunpur222003India Department of Mathematics Motihari College of EngineeringMotihari845401BiharIndia

This work is devoted to get a new family of analytical solutions of the(2+1)-coupled dispersive long wave equations propagating in an infinitely long channel with constant depth,and can be observed in an open sea or in wide *** solutions are obtained by using the invariance property of the similarity transformations method via one-parameter Lie group *** repeated use of the similarity transformations method can transform the system of PDEs into system of *** adequate restrictions,the reduced system of ODEs is *** simulation is performed to describe the solutions in a physically meaningful *** profiles of the solutions are simulated by taking an appropriate choice of functions and constants involved *** each animation,a frame for dominated behavior is *** exhibit elastic multisolitons,single soliton,doubly solitons,stationary,kink and parabolic *** results are significant since these have confirmed some of the established results of *** et al.(2020)and *** et al.(2020).Some of their solutions can be deduced from the results derived in this *** results in the existing literature are different from those in this work.

关键词： Dispersive long wave equations Solitons Invariants Lie-group Similarity solutions

Dynamics of some new solutions to the coupled DSW equations traveling horizontally on the seabed

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Journal of Ocean Engineering and Science 2024年第2期9卷 154-163页

作者： Raj kumar ravi Shankar Verma Department of Mathematics Faculty of Engineering&TechnologyVeer Bahadur Singh Purvanchal UniversityJaunpur 222003India

The system of(1+1)-coupled Drinfel’d-Sokolov-Wilson equations describes the surface gravity waves travelling horizontally on the *** objective of the present research is to construct a new variety of analytical solutions for the *** invariants are derived with the aid of Killing form by using the optimal algebra classification via Lie symmetry *** invariant solutions involve time,space variables,and arbitrary *** adequate constraints on arbitrary constants,solutions are represented graphically to make them more applicable in designing sea *** behavior of solutions shows asymptotic,bell-shaped,bright and dark soliton,bright soliton,parabolic,bright and kink,kink,and periodic *** constructed results are novel as the reported results[26,28,29,30,33,38,42,49]can be deduced from the results derived in this *** remaining solutions derived in this study,are absolutely different from the earlier *** this study,the physical character of analytical solutions of the system could aid coastal engineers in creating models of beaches and ports.

关键词： Coupled Drinfel’d-Sokolov-Wilson model Invariants Killing form Optimal sub algebra Lie symmetry reductions