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Institution

National Institute of Technology, Karnataka

EducationMangalore, Karnataka, India
About: National Institute of Technology, Karnataka is a education organization based out in Mangalore, Karnataka, India. It is known for research contribution in the topics: Corrosion & Cloud computing. The organization has 5017 authors who have published 7057 publications receiving 70367 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, a ternary alloy was applied to mild steel from acidic baths (pH 3.5) for electrodeposited galvanostatically on mild steel.
Abstract: Zn–Fe, Zn–Ni and Zn–Ni–Fe coatings were electrodeposited galvanostatically on mild steel from acidic baths (pH 3.5) consisted of ZnCl 2 , NiCl 2 , FeCl 2 , gelatin, sulfanilic ( p -aminobenzenesulfonic) acid and ascorbic acid. Cyclic voltammetry showed that the effect of gelatin was more pronounced than that of sulfanilic acid, and that the deposition of the ternary alloy behaved differently from the deposition of the binary alloys. In all three systems, the Faradaic efficiency was higher than 88%, the rate of Zn deposition was heavily influenced by mass-transport limitation at high applied current densities, and the deposition was of anomalous type. For each applied current density, the concentrations of Ni and Fe in the ternary alloy were higher than the corresponding concentrations in the binary alloys. The hardness of Zn–Ni coatings was the highest, while that of Zn–Fe coatings was the lowest. The Zn–Ni–Fe coatings were the smoothest, had distinguished surface morphology, and contained ZnO in the bulk, not just on the surface. The lowest corrosion rate in each alloy system (214, 325 and 26 μm year −1 for Zn–Ni, Zn–Fe and Zn–Ni–Fe, respectively) was characteristic of coatings deposited at 30, 30 and 40 mA cm − 2 , respectively. The higher corrosion resistance of the ternary alloy was also reflected by a higher corrosion potential, a higher impedance and a higher slope of the Mott-Schottky line. The enhanced corrosion behavior of the ternary alloy was thus attributed to its chemical composition, phase content, roughness and the synergistic effect of Ni and Fe on the n -type semiconductor surface film.

126 citations

Journal ArticleDOI
TL;DR: In this article, the ternary Zn-Ni-Co coating was applied on mild steel from an acidic chloride bath containing p-aminobenzenesulphonic acid (SA) and gelatin.
Abstract: Zn–Ni, Zn–Co and Zn–Ni–Co coatings were electrodeposited on mild steel from an acidic chloride bath containing p-aminobenzenesulphonic acid (SA) and gelatin. These additives changed the phase content in the coatings, most likely as a result of their adsorption at the surface of the cathode. The effect of gelatin was more pronounced than that of SA. The Faradaic efficiency was higher than 90%. As the current density was increased or the bath temperature was decreased, the concentration of the nobler metal in the coating increased. Both concentrations of Ni and Co in the ternary alloy increased as the applied current density was increased. Nickel and cobalt were found to have a synergistic catalytic effect. The thickness of all coatings increased as the applied current density was increased. The hardness increased with current density to a peak value, and then decreased. The rate of Zn deposition was heavily influenced by mass-transport limitation at high applied current densities, while the rates of Ni and Co deposition were not. The anomalous codeposition was explained by the great difference between the exchange current densities of Zn and the iron-group metal. Potentiodynamic polarization scans and electrochemical impedance spectroscopy showed that the corrosion resistance of the ternary Zn–Ni–Co alloy coatings was approximately 10 times higher than that of Zn–Ni and 7 times higher than that of Zn–Co. The improved corrosion resistance of the ternary alloy was attributed to its surface chemistry, phase content, texture, and surface morphology. The ternary Zn–Ni–Co coating may thus replace the conventional Zn–Ni and Zn–Co coatings in a variety of applications.

126 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a new nine-level inverter for medium and high power applications, which consists of a three-level active neutral-point-clamped (ANPC) inverter connected in series with a floating capacitor (FC) fed H-bridge.
Abstract: This paper proposes a new nine-level inverter for medium- and high-power applications. The proposed topology comprises of a three-level (3L) active neutral-point-clamped (ANPC) inverter connected in series with a floating capacitor (FC) fed H-bridge. Besides, two additional switches operating at line frequency are appended across the dc link of the 3L ANPC structure. Compared with conventional hybrid cascaded inverters, the primary advantage of this addition is doubling of the resulting root mean square output voltage. This amelioration is achieved while preserving the standard 3L ANPC and H-bridge structures with minimum topological modification. A simple logic-gate-based voltage balancing scheme is developed to regulate the FC voltage. The proposed voltage balancing method is independent of load power factor, inverter modulation index, and can balance the voltage across FC instantaneously. The step-by-step formulation of logical expressions for the generation of gating pulses is deliberated in detail and can be generalized for any $n$ -level inverter. Further, simulation results as well as the experimental measurements obtained from the laboratory prototype are presented to validate the effectiveness and practicability of the proposed configuration. Finally, the notable merits of the proposed inverter over the prior art topologies is established through a comprehensive comparative study.

124 citations

Journal ArticleDOI
TL;DR: In this article, the degradation temperature of composite NiO nanofibres was determined by X-ray diffraction, which revealed the complete elimination of the organic phase from NiO fibres during calcination.
Abstract: In this study, nickel oxide (NiO) nanofibres were obtained by a sol–gel electrospinning process followed by calcination from an aqueous sol of poly(2-ethyl-2-oxazoline)/nickel acetate tetrahydrate. Thermogravimetric analysis was used to determine the degradation temperature of the composite fibres, so as to get nickel oxide nanofibres. X-ray photoelectron spectroscopy and X-ray diffraction studies revealed the complete elimination of the organic phase from NiO fibres during calcination. The change in grain size with calcination temperature was determined by X-ray diffraction. The defects in fibres resulted in the modification of their Raman spectra as compared with that of a single crystal. The magnetic properties of the fibres were reduced as the calcination temperature was increased; this is due to the presence of non-stoichiometric defects. As the calcination temperature was increased, the amount of defects was reduced, which induced a difference in the band gap energy of the fibres. Sensitivity of the NiO fibres towards five different alcohols was studied, and the sensitivity towards ethanol was the highest.

123 citations

Journal ArticleDOI
TL;DR: In this article, the harmful effects of various substances on the marine environment were reviewed by collecting and studying the relevant literature and various sources for the pollution of marine environment are identified and the causes for the same are understood.

123 citations


Authors

Showing all 5100 results

NameH-indexPapersCitations
Ajay Kumar5380912181
Bhiksha Raj5135913064
Alexander P. Lyubartsev491849200
Vijay Nair4742510411
Sukumar Mishra444057905
Arun M. Isloor382616272
Vinay Kumaran362624473
M. C. Ray301152662
Airody Vasudeva Adhikari301192832
Ian R. Lane271292947
D. Krishna Bhat26951715
Anurag Kumar261262276
Soma Biswas251272195
Chandan Kumar25661806
H.S. Nagaraja23901609
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202351
2022175
2021938
2020893
2019838
2018740