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Institution

Indian Institute of Technology Guwahati

EducationGuwahati, Assam, India
About: Indian Institute of Technology Guwahati is a education organization based out in Guwahati, Assam, India. It is known for research contribution in the topics: Adsorption & Catalysis. The organization has 6933 authors who have published 17102 publications receiving 257351 citations.


Papers
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Journal ArticleDOI
TL;DR: It is shown that the observed FM data fits well with the BMP model involving localised carriers and magnetic cations, based on the bound magnetic polaron (BMP) model.
Abstract: Structural, optical and magnetic studies have been carried out for the Co-doped ZnO nanoparticles (NPs). ZnO NPs are doped with 3% and 5% Co using ball milling and ferromagnetism (FM) is studied at room temperature and above. A high Curie temperature (Tc) has been observed from the Co doped ZnO NPs. X-ray diffraction and high resolution transmission electron microscopy analysis confirm the absence of metallic Co clusters or any other phase different from wurtzite-type ZnO. UV-visible absorption and photoluminescence studies on the doped samples show change in band structure and oxygen vacancy defects, respectively. Micro-Raman studies of doped samples shows defect related additional strong bands at 547 and 574 cm(-1) confirming the presence of oxygen vacancy defects in ZnO lattice. The field dependence of magnetization (M-H curve) measured at room temperature exhibits the clear M-H loop with saturation magnetization and coercive field of the order of 4-6 emu/g and 260 G, respectively. Temperature dependence of magnetization measurement shows sharp ferromagnetic to paramagnetic transition with a high Tc = 791 K for 3% Co doped ZnO NPs. Ferromagnetic ordering is interpreted in terms of overlapping of polarons mediated through oxygen vacancy defects based on the bound magnetic polaron (BMP) model. We show that the observed FM data fits well with the BMP model involving localised carriers and magnetic cations.

75 citations

Proceedings ArticleDOI
08 May 2014
TL;DR: The developed system uses text independent speaker verification with MFCC features and i-vector based speaker modeling for authenticating the user and linear discriminant analysis and within class covariance normalization are used for normalizing the effects due to session/environment variations.
Abstract: In this paper we present the development and implementation of a speech biometric based attendance system The users access the system by making a call from few pre-decided mobile phones An interactive voice response (IVR) system guides a new user in the enrollment and an enrolled user in the verification processes The system uses text independent speaker verification with MFCC features and i-vector based speaker modeling for authenticating the user Linear discriminant analysis and within class covariance normalization are used for normalizing the effects due to session/environment variations A simple cosine distance scoring along with score normalization is used as the classifier and a fixed threshold is used for making the decision The developed system has been used by a group of 110 students for about two months on a regular basis The system performance in terms of recognition rate is found to be 942 % and the average response time of the system for a test data of duration 50 seconds is noted to be 26 seconds

75 citations

Journal ArticleDOI
TL;DR: In this paper, a mechanistic investigation of hybrid advanced oxidation processes with combinations of sonolysis and Fenton process coupled with UV was presented, where a ubiquitous pollutant, bisphenol A, discharged in environment with solid plastic waste was used as the model reaction.
Abstract: Hybrid advanced oxidation processes (HAPOs) for degradation of recalcitrant organic pollutants have been extensively studied in recent literature. In this paper, we have presented a mechanistic investigation of hybrid advanced oxidation processes with combinations of sonolysis and Fenton process coupled with UV. Degradation of a ubiquitous pollutant, bisphenol A, discharged in environment with solid plastic waste has been used as the model reaction. Essentially, an attempt is made to explore synergy between the individual mechanisms of these processes. With conjectures of possible synergies, we have devised the experimental protocols with combination of sonolysis and Fenton process coupled with UV. It is revealed that techniques of sonolysis + Fe2+ and sono–Fenton have positive synergy while technique of Fenton process + UV has no synergy. The technique of sono–Fenton + UV has been found to have negative synergy. The rationales for positive synergy have been identified as conservation and/or regeneration ...

75 citations

Journal ArticleDOI
TL;DR: In this article, a cross linked pegylated functional copolymer poly (ACrylic acid-co-polyethylene glycol methyl ether methacrylate) was prepared from AA and PEGMA, via precipitation polymerization using toluene as solvent.

75 citations

Journal ArticleDOI
A. Zupanc, L. Santelj, Y. Yusa1, A. Abdesselam2  +165 moreInstitutions (58)
TL;DR: In this paper, a measurement of the time-dependent CP violation parameters in B0 -> eta'K-0 decays was presented based on the full data sample containing 772 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance using the Belle detector at the KEKB asymmetric-energy e+e collider.
Abstract: We present a measurement of the time-dependent CP violation parameters in B0 -> eta'K-0 decays. The measurement is based on the full data sample containing 772 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance using the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured values of the mixing-induced and direct CP violation parameters are: sin 2 phi(eff)(1) = +0.68 +/- 0.07 +/- 0.03, A(eta'K0) = +0.03 +/- 0.05 +/- 0.04, where the first uncertainty is statistical arid the second is systernatic. The values obtained are the most accurate to date. lurthierrimore. these results are consistent with our previous measurements and with the world-average value of sin 2 phi(1) measured in B-0 -> J/psi K-0 decays.

75 citations


Authors

Showing all 7128 results

NameH-indexPapersCitations
Jasvinder A. Singh1762382223370
Dipanwita Dutta1431651103866
Sanjay Gupta9990235039
Santosh Kumar80119629391
Subrata Ghosh7884132147
Rishi Raj7856922423
B. Bhuyan7365821275
Ravi Shankar6667219326
Ashutosh Sharma6657016100
Gautam Biswas6372116146
Sam P. de Visser6225613820
Surendra Nadh Somala6114428273
Manish Kumar61142521762
Mihir Kumar Purkait572679812
Ajaikumar B. Kunnumakkara5720120025
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023118
2022365
20212,032
20201,947
20191,866
20181,647