Using graphene based nanocomposities to control the dynamics of oscillatory reactions and its application in monosaccharides quantification

by Sachin VermaM.Tech

A Strongly Correlated Quantum-Dot Heat Engine with Optimal Performance: An Non-equilibrium Green's function Approach

We present an analytical study of a strongly correlated quantum dot-based thermoelectric particle-exchange heat engine for both finite and infinite on-dot Coulomb interaction. Employing Keldysh's non-equilibrium Green's function formalism for different decoupling schemes in the equation of motion, we have analyzed the thermoelectric properties within the non-linear transport regime. As the simplest mean-field approximation is insufficient for analyzing thermoelectric properties in the Coulomb blockade regime, one needs to employ a higher-order approximation to study strongly correlated QD-based heat engines. Therefore initially, we have used the Hubbard-\Romannum{1} approximation to study the quantum dot level position ($\epsilon_d$), thermal gradient ($\Delta T$), and on-dot Coulomb interaction ($U$) dependence of the thermoelectric properties. Furthermore, as a natural extension, we have used an approximation beyond Hubbard-\Romannum{1} in the infinite-$U$ limit (strong on-dot Coulomb repulsion) to provide additional insight into the operation of a more practical quantum dot heat engine. Within this infinite-$U$ limit, we examine the role of the symmetric dot-reservoir tunneling ($\Gamma$) and external serial load resistance ($R$) in optimizing the performance of the strongly correlated quantum dot heat engine. Our infinite-$U$ results show a good quantitative agreement with recent experimental data for a quantum dot coupled to two metallic reservoirs.Comment: 14 pages 7 figure

Seebeck power generation and Peltier cooling in a Normal metal-quantum dot-superconductor nanodevice

We theoretically investigate the Seebeck and Peltier effect across an interacting quantum dot(QD) coupled between a normal metal and a Bardeen-Cooper-Schrieffer superconductor within the Coulomb blockade regime. Our results demonstrate that the thermoelectric conversion efficiency at optimal power output (optimized with respect to QD energy level and external serial load) in NQDS nanodevice can reach up to $58\%\eta_C$, where $\eta_C$ is Carnot efficiency, with output power $P_{max}\approx 35fW$ for temperature below the superconducting transition temperature. Further, the Peltier cooling effect is observed for a wide range of parameter regimes, which can be optimized by varying the background thermal energy, QD level energy, QD-reservoir tunneling strength, and bias voltage. The results presented in this study are within the scope of existing experimental capabilities for designing miniature hybrid devices that operate at cryogenic temperatures.Comment: 13 pages, 2 figure

Mean-Field Study of Normal Metal-Quantum Dot-Superconductor System in the Presence of External Magnetic Field

In this paper, we have analyzed the spectral and transport properties of a weakly correlated single-level quantum dot hybridized with one normal conducting and another Bardeen-Cooper-Schrieffer (BCS) superconducting lead (N-QD-S system) in the presence of an external magnetic field. We have employed Green's function equation of motion (EOM) approach within a self-consistent Hartree-Fock (HF) mean-field approximation to analyze the Hamiltonian. We studied the effect of on-dot Coulomb correlation and an external magnetic field on the sub-gap Andreev levels of a quantum dot, strongly coupled to a conventional s-wave superconductor as a function of impurity parameters. We have shown that for a finite magnetic field, the Andreev bound states (ABSs) split into a spin-up and spin-down contribution (i.e. Zeeman splitting) and cross the Fermi energy level, resulting in a quantum phase transition, which is an indication of a change in the fermion parity of the ground state. Further, within the non-linear regime, we discuss the total electrical conductance for various values of Zeeman energy and on-dot Coulomb interactions. We have compared our results with the existing experimental and theoretical results.Comment: 7 pages, 5 figure

Conservative Bridge with Natural Tooth Pontic: A Case Report

AIMS AND OBJECTIVES A CONSERVATIVE SOLUTION FOR AN ESTHETIC CHALLANGE PROVIDING SINGLE VISIT AND A CHAIR SIDE PROCEDURE TO IMPROVE A SMILE   CASE DISCRIPTION Conservative solutions  for the restoration of a single edentulous space in the anterior maxilla present an esthetic challenge to the clinician.A 24-year-old female patient whose left upper central tooth was planned to be extracted was referred to our department for a conservative, rapid, and economic treatment.After radiographic and clinical examinations, it was decided that the tooth which was to be extracted should be used for the restoration of its own extracted area. The extracted tooth was splinted using Ribbond fiber (Ribbond Inc., Seattle WA) to adjacent teeth with the aid of the surface modifications on extracted tooth and adjacent teeth . CONCLUSION  The conservative bridge with natural tooth pontic satisfied the patient with a good mechanical behavior, and long-term durability. &nbsp

Automatic Railway track Inspection for early warning using Real time image Processing with GPS

Railroad assessment assumes an indispensable part for the correct working of the rail line frameworks; in the past its done manual investigation yet has a few ambiguities. Modified vision based audit systems are engaged to look at the stipulation of rail track. Thusly system fabricates the capability of audit, reduces the required time and giving a more exact and ceaseless information of the railroad track. To give the continuous screens and assistant condition for railroad track using "vision based" and "vibration based" strategy for wellbeing reason. Thusly we can bolster exactness, adequacy and steadfastness. PC vision frameworks have been especially made to be used with the model. The structure delineated in this suggestion makes use of different standard and balanced picture get ready systems, not simply to facilitate the necessities for manual examinations, furthermore to allow steady checking and taking after of any blemishes or varieties from the standard in a rail track. Hereafter to keep up a vital separation from deferments, our propose structure will thusly survey the railroad track by using vision based and vibration based technique. The system gives continuous watching and essential condition for railroad track using vision based procedure and change in accordance with look for the inadequacy range on the track. An examination join perceiving disfigurements on tracks, missing shocks, stay, tie plate and fastens et cetera

Multiple DRPs to maximise the techno-economic benefits of the distribution network

This study addresses a demand response programme (DRP) model considering the price elasticity of demand to determine the peak scheduling for different categories of consumers with the possibility of load shifting. The main objective is to minimise daily energy loss and improvement in the node voltage profile of distribution system along with the economic benefits of different stakeholders. The proposed work helps in appropriate selection of DRP for different feeders/consumers. The investigations are performed on a benchmark 33-bus test distribution system and comprehensive analysis is illustrated through simulation results