538 research outputs found
Fiber design for high-power low-cost Yb:Al-doped fiber laser operating at 980nm
No full textWe investigated an Yb:Al-doped depressed-clad hollow optical fiber (DCHOF) for cladding-pumped 980nm laser operation. With a careful design, the nonzero fundamental-mode cutoff characteristics of a DCHOF allows the competing 1030-1060nm emission to be filtered out, despite being quite close to 980nm. The laser yielded over 3W of output power in a diffraction limited beam (M -parameter degrades to 2.7, as a result of increased cladding-mode lasing, as the cladding thickness is reduced
Implementation of MSK Modulation Scheme for Zigbee System IEEE 802.15.4 Physical Layer
No full textIn this work physical layer simulation of IEEE 802.15.4 ZigBee protocol has been done. The proposed work is the implementation of ZigBee system according to the protocol description. In this work we have simulated ZigBee system first with conventional OQPSK modulation technique, then the simulations are performed for MSK modulation, which is through OQPSK modulation. Simulation results for BER showing the average 79.43 improvement in BER for Proposed MSK compared with OQPSK modulation scheme. For a target BER of 10 2 the SNR required is 4 dB for this work i.e. for MSK, as compared to 10 dB for conventional OQPSK. Hence, an improvement of 6 dB less SNR. For a target BER of 10 2 the SNR required is 4 dB for this work i.e. for MSK, as compared to 5.2 dB with 1 . Hence, an improvement of 1.2 dB less SNR. Kumari Pooja | Shailesh Khaparkar | Pankaj Sahu "Implementation of MSK Modulation Scheme for Zigbee System / IEEE 802.15.4 Physical Layer" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-4 , June 2018, URL: https://www.ijtsrd.com/papers/ijtsrd14609.pd
E-Journal of Chemistry from 2007 to 2012: A Bibliometric Study
No full textBibliometric research is a complex area to comprehend and to undertake in which one might expect information about the intricacies of identifying data for a bibliometric study, discussion about what that data means when it has been extracted, as well as details about the assumptions and limitations researchers face when working in the field, will need to consult an alternative source (Haddow, 2010). Now-a-days, bibliometric studies are conducted for a given field of knowledge on specific literature, research output of a prolific author, research productivity of an organization or of an individual journal for a specific range of time. The present study attempts to unfold the publication characteristics of E-Journal of Chemistry which is published by World Wide Web Publications (P) India from the USA
WITHDRAWN: In vitro micro propagation of Withania somnifera (L.) Dunal
No full textThis article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause.The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy
Experimental Investigation and Optimization of Parameters in Electrochemical Machining Operation
No full textElectrochemical Machining is a non-traditional machining process which is used to machine difficult-to-machine materials such as super alloys, Ti-alloys, stainless steel etc. The basic working principle is based on Faraday law of electrolysis due to which the material removal takes place atom by atom by the process of electrolysis. This experiment highlights features of the development of a comprehensive mathematical model for correlating the interactive and higher order influences of various machining parameters on the dominant machining criteria i.e. the material removal rate (MRR), surface roughness (SR) and overcut (OC) phenomenon through Response Surface Method (RSM) method using the pertinent experimental data as obtained by experiment. The present work has been undertaken to find the material removal rate, surface roughness and overcut by electrochemical dissolution of an anodically polarized work piece (AISI304 stainless steel) with a copper electrode of hexagonal cross section. Experiments were conducted to analyse the influence of machining parameters such as feed rate, voltage and electrolyte concentration. Analysis of variance (ANOVA) is employed to indicate the level of significance of machining parameters. It is observed that concentration is the most significant factor for response of material removal rate and in case of surface roughness voltage is the most significant factor. For response of overcut, the voltage is most significant factor
Radiation Hardness of Undoped BGO Crystals
No full textWe measured the radiation hardness of undoped BGO crystals from two different manufacturers. Such crystals are proposed to be used in a small angle calorimeter of the BELLE detector of the KEK B-factory. Transparency and scintillation light output of the crystals were monitored to see the effect of radiation damage. The crystals show considerable radiation hardness up to 10.2 MRad equivalent dose, which is much higher than the maximum expected dosage of 500 kRad per year of running at BELLE. Submitted to NIM-A. y Corresponding author; Present address : University of Hawaii, Honolulu, HI 96822, U.S.A.; [email protected] 1 Introduction Bismuth Germanate (Bi 4 Ge 3 O 12 ) crystals, commonly known as BGO, have been extensively used for electromagnetic calorimetry in high energy physics experiments[1]. Advantages of BGO are its excellent e=fl energy resolution (0.3 -- 1 %/ q (E(GeV )), high density, short radiation length, large refractive index, suitable scintillating properties(f..
EXPERIMENTAL ANALYSIS OF HEAT FLUX AND EVAPORATIVE EFFECTIVENESS OF COPPER COIL OF HEAT DISSIPATOR
No full textOnline monitoring of voltage stability margin using PMU measurements
No full textWith the growing smart grid concept it becomes important to monitor health of the power system at regular intervals for its secure and reliable operation. Phasor Measurement Units (PMUs) may play a vital role in this regard. This paper presents voltage stability monitoring in real time framework using synchrophasor measurements obtained by PMUs. Proposed approach estimates real power loading margin as well as reactive power loading margin of most critical bus using PMU data. As system operating conditions keep on changing, loading margin as well as critical bus information is updated at regular intervals using fresh PMU measurements. Simulations have been carried out using Power System Analysis Toolbox (PSAT) software. Accuracy of proposed Wide Area Monitoring System (WAMS) based estimation of voltage stability margin has been tested by comparing results with loading margin obtained by continuation power flow method (an offline approach for accurate estimation of voltage stability margin) under same set of operating conditions. Case studies performed on IEEE 14-bus system, New England 39-bus system and a practical 246-bus Indian power system validate effectiveness of proposed approach of online monitoring of loading margin
Editorial Introduction
No full textPoet, professor, critic and folklorist Nandini Sahu is one of the most important figures in contemporary Indian writing in English. The sky-high number of her readers, making her the Amazon’s bestselling author for 2022, is a testimony to the sea-deep quality of her works. A professor by profession, a poet by essentiality, and a folklorist to the core, Nandini Sahu has touched the life and soul of many, in many ways. Her poetic output, one after the other, showed us new lights in which to see truth––an unfabricated truth
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