Electrical Engineering

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

In this work, we have studied the fluorescence quenching and solid state diffusion of 2, 3, 5, 6-tetrafluoro-7, 7′, 8, 8′-tetracyano quinodimethane (F4-TCNQ) using photoluminescence (PL) spectroscopy. Quenching studies were performed with tris (8-hydroxyquinolinato) aluminum (Alq3) in solid state samples. Thickness of F4-TCNQ was varied in order to realize different concentrations and study the effect of concentration. PL intensity has reduced with the increase in F4-TCNQ thicknesses. Stern-Volmer and bimolecular quenching constants were evaluated to be 13.8 M-1 and 8.7 × 108 M-1 s-1, respectively. The quenching mechanism was found to be of static type, which was inferred by the independent nature of excited state life time from the F4-TCNQ thickness. Further, solid state diffusion of F4-TCNQ was studied by placing a spacing layer of α-NPD between F4-TCNQ and Alq3, and its thickness was varied to probe the diffusion length. PL intensity was found to increase with the increase in this thickness. Quenching efficiency was evaluated as a function of distance between F4-TCNQ and Alq3. These studies were performed for the samples having 1, 2.5, and 5.5 nm thicknesses of F4-TCNQ to study the thickness dependence of diffusion length. Diffusion lengths were evaluated to be 12.5, 15, and 20 nm for 1, 2.5, and 5.5 nm thicknesses of F4-TCNQ. These diffusion lengths were found to be very close to that of determined by secondary ion mass spectroscopy technique. © 2015 AIP Publishing LLC.

World University root node

(SoE) School of Engineering

Fulltext

Journal of Chemical Physics

Study of fluorescence quenching due to 2, 3, 5, 6-tetrafluoro-7, 7′, 8, 8′-tetracyano quinodimethane and its solid state diffusion analysis using photoluminescence spectroscopy

We demonstrate white organic light emitting diodes with enhanced efficiency (26.8 lm/W) and life time (∼11 000 h) by improved heat dissipation through encapsulation composed of a metal (Cu, Mo, and Al) and mica sheet joined using thermally conducting epoxy. Finite element simulation is used to find effectiveness of these encapsulations for heat transfer. Device temperature is reduced by about 50% with the encapsulation. This, consequently, has improved efficiency and life time by about 30% and 60%, respectively, with respect to glass encapsulation. Conductive cooling of device is suggested as the possible cause for this enhancement. © 2015 AIP Publishing LLC.

Applied Physics Letters

Conductive cooling in white organic light emitting diode for enhanced efficiency and life time

The beam width of microwave antennas can be easily determined using infrared thermography. A thin absorption screen made up of some carbon loaded polymer is placed in front of a microwave antenna. The electromagnetic waves impinging the screen are partially absorbed by it, resulting in temperature rise of this screen. This temperature rise is monitored by an infrared camera. These infra red images of the temperature distribution are identical to the power distribution of the incident electromagnetic field at the screen location. The distance between half power points on the main lobe of the radiation pattern at the screen location in two orthogonal directions (E- and H-planes) can be easily found. From these distances the half power beam widths in both E- and H-planes can be calculated. Further from these beam widths, directivity is also calculated. The experiments were carried with a patch antenna radiating at 2.45 GHz. In order to show the repeatability of the results, experiments were carried for different distances between patch antenna and absorption screen. A great agreement is seen between simulation, measurement and experimental (thermographic) results. The microwave source is modulated at a low frequency so as to avoid the lateral spread of heat on the absorption screen and to permit lock-in detection of temperature distribution. © 2015 Elsevier B.V.

Infrared Physics and Technology

Beam width estimation of microwave antennas using lock-in infrared thermography

Solar Energy is a clean and boundless energy source and the worldwide solar market demand is increasing for industrial and domestic purposes. The purpose of this paper is to show the comparison of Stochastic Method(Genetic Algorithm) over derivative methods. A mathematical development [3] is provided for the extraction of Solar Panel equivalent circuit parameters from datasheet values. The analytical approach is selected for the mathematical development as the initial-point vital for proper evaluation of the Parameters of the double diode Model of PV cells. And thus using Evolutionary technique to extract the values of the parameters, a valid comparison has been presented between the numerical approaches and the Evolutionary Algorithms. © 2015 IEEE.

2015 1st Conference on Power, Dielectric and Energy Management at NERIST, ICPDEN 2015

Parameter estimation of double diode photo-voltaic module

Network on Chip (NoC) architecture needed secured data processing and routing in multicore system on Chip (SoC). Sometime it becomes very difficult to provide secured network routing for physically access network. The performance of NoC architecture depends on switching techniques, routing scheme and topological structure. The paper proposed the chip implementation of the new technique of securing data in NoC routers. Many algorithms have been anticipated already for secured NoC routing but limited to their key size and block size. In the paper, NoC architecture is integrated with modified TACIT security algorithm on Virtex-5 FPGA. The key generation scheme is considered based on Hash function and distributed under 4 Hash function (4H) scheme. The greatest advantage of TACIT security algorithm is that the block size and key size both can be of 'n' bit. The design is developed for 'n' bit with the help of VHDL programming language in Xilinx ISE 14.2 and Modelsim 10.1 b software and synthesized for 512 and 1024 bit of block size on Virtex-5 FPGA. The design is optimized with the help of device utilization summary, timing parameters, maximum frequency and memory support. © 2015 The Authors. Published by Elsevier B.V.

Procedia Computer Science

Secured Network on Chip (NoC) architecture and routing with modified tacit cryptographic technique

Telecommunication networks are based on crossbar switching structure. Non-blocking crossbar switching structure is used crosspoint switch fabric ICs. High performance non-blocking matrixes cross point switches are use to avoid the congested path to the output, and eliminate the bandwidth problem of one at a time. Telecommunication switching uses multistage crossbar switching to overcome the limitations of individual chips or boards. The research paper focuses on the FPGA implementation of 64 x 64 three stage telecommunication switching. The generic architecture scheme is followed to implement 64 x 64 three stage network configuration, with 64 inlets and 64 outlets as cluster size. The design is developed with the help of Xilinx ISE 14.2, software, synthesized on Virtex- 5 FPGA, and function simulation is carried out in Modelsim 10.1b student edition. Very High Speed Integrated Circuit Hardware Description Language (VHDL) is used to develop the design. © 2015 The Authors. Published by Elsevier B.V.

Design and FPGA synthesis of three stage telecommunication switching in HDL environment

Battery powered wireless sensor networks (WSN) although can be installed at reduced cost but due to their high powerconsumption and corresponding need for regular battery replacement has made wireless sensor network difficult andcostly to maintain. Energy harvesting is the process by which energy readily available from the environment, and iscaptured and converted into usable electrical energy. Combining WSN nodes with energy harvesters one can approach to even a'Greener' world. This evaluation will make the revolution towards long-lived large scale sensor networks. Thechallenge is in the WSN node integration with an energy harvester, power management, energystorage, communications, and range of sensor types. This paper briefly discusses the trends in energy harvestingtechnologies used for WSN. It also reviews various energy harvesting technologies currently available or underdevelopment. © 2015 IEEE.

2015 International Conference on Signal Processing and Communication, ICSC 2015

Recent trends in energy harvesting for green wireless sensor networks

In this paper, an effort has been made to study the recently developed pseudospark discharge-based 20 kV/200 A plasma cathode electron gun by using 3-D particle-in-cell simulation code VORPAL for discharge current analysis to validate the experiments. The experimental and simulation studies have been performed at different working pressures between 50 and 100 mTorr and at different applied voltages between 10 and 20 kV. Argon has been used as the working gas. The temporal behavior of the discharge current, discharge voltage, potential distribution within the hollow cathode region and the electron plasma density buildup has been analyzed from the simulations. The experiments have been performed to measure the dynamic nature of the discharge voltage and discharge current at different operating conditions. An agreement between the simulated and experimental results has been obtained well within 10 % for the discharge currents at different applied voltages, qualifying the design. © 2015, Indian Association for the Cultivation of Science.

Indian Journal of Physics

Simulation and experimental studies of 20 kV/200 A PCE-Gun for discharge current analysis

An enlargement of candidate vector set of QR-LRL (QR - Least Reliable Layer) based MIMO detector for efficient soft output generation is proposed. Previous work [8] shows that QR-LRL based MIMO detector approaches hard decision output ML performance, but does not match the soft output ML performance due to empty candidate vector set problem. Performance degradation is more severe when modulation order is low. Some of the previous methods have provided solutions to mitigate Empty Vector Set (EVS) problem [4] [8] [9], but are not efficient in terms of performance or computation complexity. In this paper, we enlarged candidate vector set of QR-LRL detector by applying every constellation point at each layer. The proposed detector thus effectively removes EVS problem and achieves soft ML performance while keeping the computation complexity low, especially at low modulation order. © 2014 IEEE.

IEEE Region 10 Annual International Conference, Proceedings/TENCON

Enlarged QR-LRL based SM-MIMO detector for efficient soft output generation

A fast and easy method for fault detection in antenna arrays using infrared thermography is presented. A thin, minimally perturbing, microwave absorption screen made of carbon loaded polymer is kept close in front of the faulty array. Electromagnetic waves falling on the screen increase its temperature. This temperature profile on the screen is identical to electric field intensity profile at the screen location. There is no temperature rise observed on the screen corresponding to non-radiating (faulty) elements and hence can be easily detected by IR thermography. The array input power is modulated at a low frequency which permits thermography to detect even weak fields. It also improves the resolution of thermal images. The power fed to the array is only 30 dBm. In order to show the utility of this technique, an example of 14 GHz 4 × 4 patch antenna array is given. The simulations are carried in CST Microwave Studio 2013. A good agreement between simulation and experimental results is observed. © 2015 Elsevier B.V. All rights reserved.