pushpendra kumar | MIT Moradabad (U.P.) (original) (raw)

Papers by pushpendra kumar

The journal of physical chemistry. A, Jan 17, 2015

Structural, electronic, and optical properties of a new coumarin dye, zinc oxide (ZnO) nanocluste... more Structural, electronic, and optical properties of a new coumarin dye, zinc oxide (ZnO) nanoclusters of varying sizes, and their complexes have been investigated using density functional theory (DFT). The band gap of oxide nanoclusters varies with size validating quantum confinement effect in small particles. Energy level diagrams of dye, ZnO nanoclusters, and redox electrolyte are in favor of efficient electron injection from dye to nanocluster and regeneration of the ionized dye. The adsorption of the organic dye to nanocluster is tested for anchoring through three different functional groups (cyano, carbonyl, and hydroxyl) of the dye. We have compared simulated absorption spectra of the dye, nanoclusters, and dye functionalized nanoclusters and discussed the matching with the solar irradiance spectrum. A strong new band appeared in the low energy side of the absorption spectra for dye adsorbed nanoclusters. Frontier molecular orbital calculations reveal that the first absorption b...

Journal of Photochemistry and Photobiology A: Chemistry, 2014

We examine the quenching of the visible emission of zinc oxide (ZnO) nanocrystals (NCs) in the pr... more We examine the quenching of the visible emission of zinc oxide (ZnO) nanocrystals (NCs) in the presence of Rhodamine B (RhB) molecules. Spectroscopic measurements reveal that the quenching is nonuniform over the entire emission envelope and this quenching could be explained by the energy transfer from NCs to RhB molecules under Förster formalism. Analysis of the steady state and time-resolved emission data of ZnO NCs demonstrate that at least three defect transitions are associated with the visible emission of ZnO NCs. These transitions are completely decoupled and thereby interact individually with the RhB molecules resulting in wavelength dependent energy transfer and hence uneven quenching of the NC fluorescence. Moreover, we determine the parameters for fluorescence resonance energy transfer (FRET) from NCs to RhB molecules.

The paper presents GIS based spatial data analysis for landslide susceptibility mapping in parts ... more The paper presents GIS based spatial data analysis for landslide susceptibility mapping in parts of Sikkim Himalaya. Six important causative factors for landslides were selected and corresponding thematic data layers were prepared in GIS. The input data were collected from the topographic maps, satellite image, field data and published maps. Numerical weights for dierent categories of these factors were determined based on a statistical approach and then integrated in GIS environment to arrive at landslide susceptibility map of the area. The landslide susceptibility map classifies the area into five classes of landslide susceptible zones i.e., very high, high, moderate, low and very low. An attempt was also made to validate the map with the existing landslides of the area.

Journal of Mountain Science, 2008

Landslide susceptibility map delineates the potential zones for landslides occurrence. The paper ... more Landslide susceptibility map delineates the potential zones for landslides occurrence. The paper presents a statistical approach through spatial data analysis in GIS for landslide susceptibility mapping in parts of Sikkim Himalaya. Six important causative factors for landslide occurrences were selected and corresponding thematic data layers were prepared in GIS. Topographic maps, satellite image, field data and published maps constitute the input data for thematic layer preparation. Numerical weights for different categories of these factors were determined based on a statistical approach and the weighted thematic layers were integrated in GIS environment to generate the landslide susceptibility map of the area. The landslide susceptibility map classifies the area into five different landslide susceptible zones i.e., very high, high, moderate, low and very low. This map was validated using the existing landslide distribution in the area.

Nanoscale, Jan 15, 2015

Elementary sulphur (S) has been shown to be an excellent cathode material in energy storage devic... more Elementary sulphur (S) has been shown to be an excellent cathode material in energy storage devices such as Li-S batteries owing to its very high capacity. The major challenges associated with the sulphur cathodes are structural degradation, poor cycling performance and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling. Tremendous efforts made by others have demonstrated that encapsulation of S materials improves their cycling performance. To make this approach practical for large scale applications, the use of low-cost technology and materials has become a crucial and new focus of S-based Li-ion batteries. Herein, we propose to use a low temperature spraying process to fabricate graphene/S electrode material, where the ink is composed of graphene flakes and the micron-sized S particles prepared by grinding of low-cost S powders. The S particles are found to be well hosted by highly conductive graphene flakes and consequently su...

16th International IEEE Conference on Intelligent Transportation Systems (ITSC 2013), 2013

ABSTRACT Modeling of traffic dynamic is important for the good traffic management which leads to ... more ABSTRACT Modeling of traffic dynamic is important for the good traffic management which leads to sustainable transport. Traffic models are classified based on level of details they provide as microscopic models and macroscopic models. A microscopic model of traffic flow describes the behavior of individual vehicle in response to motion of the vehicle preceding it, while, a macroscopic model describes the behavior of the traffic as a whole, but the behavior of individual vehicle is not described. In the present work, we develop a microscopic model of car-following behavior of the vehicles and introduce the sub-microscopic model of traffic, in which the dynamic model of each vehicle is developed, which is not considered in most of the existing microscopic models. Then, a model based control strategy is proposed for the local control of the platoon of the intelligent autonomous vehicles (IAVs). This model based control strategy analytically provides the calculation of necessary effort for the follower IAV to maintain the safe inter-distance with the leader IAV.

Proceedings of the 19th IFAC World Congress, 2014

International Journal of Intelligent Mechatronics and Robotics, 2011

Wheeled mobile rovers are being used in various missions for planetary surface exploration. In th... more Wheeled mobile rovers are being used in various missions for planetary surface exploration. In this paper six-wheeled rover with rocker-bogie structure has been analyzed for planar case. The detailed kinematic model of the rover has been build and the dynamic model has been derived based on bond graph. The simulation studies have been performed for obstacle climbing capability of the rover. It has been observed from the study that rover can pass through plane surface, inclined surface, and inclined ditch without any control on the actuators of the rover.

IEEE Transactions on Intelligent Transportation Systems, 2000

ABSTRACT Currently traffic management is becoming more important to achieve the goal of sustainab... more ABSTRACT Currently traffic management is becoming more important to achieve the goal of sustainable transport, and a good traffic model can describe the traffic behavior efficiently. The traffic models can be classified based on level of details as submicroscopic-, microscopic-, mesoscopic-, and macroscopic-level models. In this paper, we provide a review of the four types of models (submicro, micro, meso, and macro) and then propose a multilevel model of traffic, which combines submicroscopic, microscopic, and macroscopic levels of traffic model. In this work, we do not consider the mesoscopic-level model. At the submicroscopic level, we develop a bond graph model of a four-wheeled vehicle considering the longitudinal, lateral, yaw, and actuator dynamics. At the microscopic level, we develop a car-following model based on virtual interconnections between the submicroscopic bond graph models of vehicles. Then, at the macroscopic level, we deduce macroscopic variables (average speed, density, and flow) from the submicroscopic and microscopic models. Having a multilevel model of traffic allows combining two properties of modeling simulation, one in real-time mode at microscopic and submicroscopic levels and the other at offline mode at macroscopic level. Thus, the whole supervision of the road traffic can be performed. Finally, the multilevel model of traffic is validated on a real-time simulator of vehicle dynamics, based on experimental measurements acquired from intelligent autonomous vehicles (IAVs). In addition, real experiments on IAVs are performed to validate the model.

Disease resistance traits are highly compromised in the present era of globalization and Indian p... more Disease resistance traits are highly compromised in the present era of globalization and Indian poultry industry is struggling for its survival as profitable business because of high input cost in treatment of diseases and vaccination. The resolution of genes controlling disease resistance in chickens is somewhat daunting task in most breeding schemes and disease resistance is not a high priority trait possibly because of low heritability. The continued increase in virulence and drug resistance in pathogens and growing concern over use of drugs and vaccines for livestock and poultry production have led the recently re-developing interest in “breeding for disease resistance” instead of higher production state only. Myxovirus (Mx) resistant gene is one of the important genes influencing the immune system as it has got an antiviral action against the single stranded RNA viruses including influenza virus, vesicular stomatitis virus, measles virus etc. Identification and characterization...

Journal of Nanomaterials, 2009

The most common fabrication technique of porous silicon (PS) is electrochemical etching of a crys... more The most common fabrication technique of porous silicon (PS) is electrochemical etching of a crystalline silicon wafer in a hydrofluoric (HF) acid-based solution. The electrochemical process allows for precise control of the properties of PS such as thickness of the porous layer, porosity, and average pore diameter. The effect of HF concentration in the used electrolyte on physical and electronic properties of PS was studied by visual color observation, measuring nitrogen sorption isotherm, field emission type scanning electron microscopy, Raman spectroscopy, and photoluminescence spectroscopy. It was found that with decrease in HF concentration, the pore diameter increased. The PS sample with large pore diameter, that is, smaller nanocrystalline size of Si between the pores, was found to lead to a pronounced photoluminescence peak. The systematic rise of photoluminescence peak with increase of pore diameter and porosity of PS was attributed to quantum confinement. The changes in nanocrystalline porous silicon were also clearly observed by an asymmetric broadening and shift of the optical silicon phonons in Raman spectra. The change in electronic properties of PS with pore diameter suggests possibilities of use of PS material as a template for fundamental physics as well as an optical material for technological applications.

Journal of Nanomaterials, 2007

A 55 nm samarium film capped with a 10 nm palladium overlayer switched from a metallic reflecting... more A 55 nm samarium film capped with a 10 nm palladium overlayer switched from a metallic reflecting to a semiconducting, transparent in visible state during ex-situ hydrogen loading via electrochemical means in 1 M KOH electrolytic aqueous solution at room temperature. The switching between metal to semiconductor was accompanied by measurement of transmittance during hydrogen loading/unloading. The effect of current density on switching and thermodynamic properties was studied between dihydride state (FCC phase) and trihydride state (hexagonal phase). From the plateau of partial pressure of hydrogen at x = 2.6, enthalpy of formation was calculated at different current densities. The diffusion coefficients and switching kinetics are shown to depend on applied current density.

ISRN Nanotechnology, 2011

The photoluminescence (PL) study in porous silicon (PS) with decreasing Si crystallites size amon... more The photoluminescence (PL) study in porous silicon (PS) with decreasing Si crystallites size among the pores was reported. The PL appearance is attributed to electronic confinement in columnar-like (or dotlike) structures of porous silicon. Three different pore diameter PS samples were prepared by electrochemical etching in HF-based solutions. Changes in porous silicon and Si crystallite size were studied by observing an asymmetric broadening and shift of the optical silicon phonons in Raman scattering. Fourier transform infrared spectroscopy (FTIR) was used to study the role of siloxene or other molecular species, for example, SiH x in the luminescence mechanism. This mechanism was further studied by thermal annealing of PS at different temperatures. The PL of PS sample annealed at ≥300 • C for 1 hr shows that trap electronic states appear in the energy gap of the smaller nano-crystal when Si-O-Si bonds are formed. From the observation of PL, Raman, and FTIR spectroscopy, the origin of PL in terms of intrinsic and extrinsic properties of nanocrystalline silicon was discussed.

Thin Solid Films, 2005

A 55-nm samarium film capped with a 15-nm palladium overlayer switched from a metallic reflecting... more A 55-nm samarium film capped with a 15-nm palladium overlayer switched from a metallic reflecting to a semiconducting, transparent in visible state during ex-situ hydrogen loading via electrochemical means in 1 M KOH electrolytic aqueous solution at room temperature. The optical transmittance exhibits a hysteresis effects on loading and unloading of hydrogen in SmH x thin film between x = 2 and 3. The hysteresis is discussed in terms of strain (and consequently stress) at the interface between the dihydride and trihydride. The diffusion coefficients and switching kinetics are shown to depend on applied current density. The changes of anodic overpotential with time during applied constant current discharge have been used to determine the electrochemical parameters the exchange current density i 0 and the symmetry factor b. D

JOURNAL OF NANOMATERIALS, 2007

Journal of Applied Animal Research, 2005

Paswan, C, Bhushan, B., Patra, B. N., Kumar, P., Sharma, A., Mukherjee, R., Tomar, A.K.S., Dandap... more Paswan, C, Bhushan, B., Patra, B. N., Kumar, P., Sharma, A., Mukherjee, R., Tomar, A.K.S., Dandapat, S. and Dutt, T. 2005. Relationship between the bovine major histocompatibility complex (BoLA) with somatic cell count in crossbred cattle. J. Appl. Anim. Res., 28: 129–132.Characterization of BoLA-DRB 3.2 gene was carried out in 25 crossbred cows suffering from clinical mastitis and 50 apparently

Small Ruminant Research, 2006

The insulin-like growth factor binding protein-3 (IGFBP-3) gene is a structural gene associated w... more The insulin-like growth factor binding protein-3 (IGFBP-3) gene is a structural gene associated with the growth and development of the animals. The present investigation was carried out to study nucleotide sequencing and DNA polymorphism by PCR-RFLP of IGFBP-3 gene in ...

Genome / National Research Council Canada = Genome / Conseil national de recherches Canada, Jan 11, 2015

The jungle crow (Corvus macrorhynchos) belongs to the order Passeriformes of bird species and is ... more The jungle crow (Corvus macrorhynchos) belongs to the order Passeriformes of bird species and is important for avian ecological and evolutionary genetics studies. However, there is limited information on the transcriptome data of this species. In the present study, we report the characterization of the lung transcriptome of the jungle crow using GS FLX Titanium XLR70. Altogether, 1 510 303 high-quality sequence reads with 581 198 230 bases was de novo assembled into 22 169 isotigs (isotig represents an individual transcript) and 784 009 singletons. Using these isotigs and 581 681 length-filtered (greater than 300 bp) singletons, 20 010 unique protein-coding genes were identified by BLASTx comparison against a nonredundant (nr) protein sequence database. Comparative analysis revealed that 46 604 (70.29%) and 51 642 (72.48%) of the assembled transcripts have significant similarity to zebra finch and chicken RefSeq proteins, respectively. As determined by GO annotation and KEGG pathway...

Small Ruminant Research, 2007

A study was conducted to detect polymorphism of butyrophilin (BTN) gene in sheep, cattle and buff... more A study was conducted to detect polymorphism of butyrophilin (BTN) gene in sheep, cattle and buffalo, and to explore the nucleotide variability amongst them. Alu I, Hae III and Rsa I PCR-RFLP was carried out to reveal polymorphism at BTN gene spanning over part of ...