Debasis Nayak | IIT Kharagpur (original) (raw)
Papers by Debasis Nayak
In the present work, we have studied phase formation behavior and electrochemical characteristics... more In the present work, we have studied phase formation behavior and electrochemical characteristics of various polymorphs of Manganese oxides in thin films forms deposited on stainless substrate by pulsed laser deposi-tion. Investigation of these thin films using x-ray diffraction, X-ray photo electron spectroscopy and Raman spec-troscopy reveals that the growth of various polymorphs of MnO 2 and their mixture depend on the substrate temperatures. The films deposited at 300, 400, and 450 °C contains a mixture of γ and β, β and R, β and R MnO 2 phases respectively, Whereas, film deposited at 550 and 650 °C shows a mixture of R-MnO 2 and α-Mn 2 O 3. The film containing β-and R-MnO 2 phases deposited at 450 °C shows optimum electrochemical property against sodium metal electrode. The density functional theory based analysis shows that MnO 2 polymorphs can accommodate sodium ions by intercalation mechanism in the ratio of 2:1 of Na and Mn, followed by a conversion mechanism into Mn metal and Na 2 O. Collectively, electrochemical and first principle based calculations suggests mixture of β-and R-MnO 2 is suitable as anode material.
![Research paper thumbnail of Electrochemical properties and first-principle analysis of Na x [M y Mn 1−y ]O 2 (M = Fe, Ni) cathode](https://attachments.academia-assets.com/55228906/thumbnails/1.jpg)
](Sodium-ion batteries are the commercially and environmentally viable next-generation candidates f... more Sodium-ion batteries are the commercially and environmentally viable next-generation candidates for automobiles. Structural and electrochemical aspects are greater concerns towards the development of a stable cathode material. Selecting transition metals and their composition greatly influences charge order, superstructures, and different voltage plateaus. This, in turn, influences transport properties and cyclic performance. This article aims to study the electrochemical performance, diffusivity, and structural stability of Na x [M y Mn 1−y ]O 2 (M = Fe, Ni) as cathode. Both experimental and DFT-based calculations apprehend the voltage plateaus due to redox reactions. The rate of cycling and the initial structure also influence the cycle life. The diffusion coefficient of P2-type Na 0.67 Fe 0.5 Mn 0.5 O 2 for Mn 3+/4+ redox reactions is more than that of the O3-type NaFe 0.5 Mn 0.5 O 2 while it is less for Fe 3+/4+ redox reactions, because of structural transition. The diffusion coefficient of NaNi 0.5 Mn 0.5 O 2 is less for Ni 2+/4+ redox reaction and is up to the order of 10 −11 cm 2 s −1 .
Many attempts have been made to model and optimize performance parameters of Electrical Discharge... more Many attempts have been made to model and optimize performance parameters of Electrical Discharge Machining (EDM) process. In this investigation, the experimental design includes L9 orthogonal array based on the Taguchi methodology. The corresponding effect of input current, duty cycle and spark on time, on surface integrity, has been studied on AISI D2 tool steel. The residual stress measurement is done using X-ray diffraction method. The obtained output results regarding material removal rate, surface roughness, crack density, and residual stress have been modeled and optimized by regression equation and Genetic algorithm respectively. In this investigation, a metallurgical approach has been introduced towards the explanation of the resulted optimized response parameters.
Glass fibre reinforced plastics (GFRP) are having good weight to strength ratio, so they have wid... more Glass fibre reinforced plastics (GFRP) are having good weight to strength ratio, so they have wide range of application for
many purposes. Micro drilling of GFRP produces de-lamination in it. So it is always needed to optimize the process parameters
by minimizing thrust force and torque. The process parameters and response parameters values are used here for analysing and
optimizing the micro drilling of GFRP. The introduction of peck micro drilling in lieu of direct micro drilling was found to be
responsible for lower value of torque and thrust force. The optimized result of thrust force and torque was found to be 40000
and 5 of rpm and feed respectively for both direct and peck type of micro drilling.
Int. J Adv Trends Comput Sci Eng, Nov 29, 2013
Electro chemical machining is a non conventional machining process to machine conducting hard ma... more Electro chemical machining is a non conventional
machining process to machine conducting hard materials using
anodic dissolution. The process parameters are needed to be
optimized to get better result of material removal rate (MRR) and
surface roughness (SR). In this paper MRR and SR values are
optimized by Simulated Annealing (SA) and the effect of input
parameters are determined by Taguchi Design while machining
EN-19 tool steel.
Proc. of Int. Conf. on Emerging Trends in Engineering and Technology
Many attempts has been made to model performance parameters of EDM process using ANN. For modelin... more Many attempts has been made to model performance parameters of EDM process using ANN. For modeling generally ANN architectures, learning/training algorithms and nos. of hidden neurons are varied to achieve minimum error, but the variation is made in random manner. So here a full factorial design has been implemented to achieve the optimal of above. From the ANOVA result the significance order also has been decided. After that optimal process modeling of MRR in EDM with the best of above
parameter has been performed
In the present work, we have studied phase formation behavior and electrochemical characteristics... more In the present work, we have studied phase formation behavior and electrochemical characteristics of various polymorphs of Manganese oxides in thin films forms deposited on stainless substrate by pulsed laser deposi-tion. Investigation of these thin films using x-ray diffraction, X-ray photo electron spectroscopy and Raman spec-troscopy reveals that the growth of various polymorphs of MnO 2 and their mixture depend on the substrate temperatures. The films deposited at 300, 400, and 450 °C contains a mixture of γ and β, β and R, β and R MnO 2 phases respectively, Whereas, film deposited at 550 and 650 °C shows a mixture of R-MnO 2 and α-Mn 2 O 3. The film containing β-and R-MnO 2 phases deposited at 450 °C shows optimum electrochemical property against sodium metal electrode. The density functional theory based analysis shows that MnO 2 polymorphs can accommodate sodium ions by intercalation mechanism in the ratio of 2:1 of Na and Mn, followed by a conversion mechanism into Mn metal and Na 2 O. Collectively, electrochemical and first principle based calculations suggests mixture of β-and R-MnO 2 is suitable as anode material.
Sodium-ion batteries are the commercially and environmentally viable next-generation candidates f... more Sodium-ion batteries are the commercially and environmentally viable next-generation candidates for automobiles. Structural and electrochemical aspects are greater concerns towards the development of a stable cathode material. Selecting transition metals and their composition greatly influences charge order, superstructures, and different voltage plateaus. This, in turn, influences transport properties and cyclic performance. This article aims to study the electrochemical performance, diffusivity, and structural stability of Na x [M y Mn 1−y ]O 2 (M = Fe, Ni) as cathode. Both experimental and DFT-based calculations apprehend the voltage plateaus due to redox reactions. The rate of cycling and the initial structure also influence the cycle life. The diffusion coefficient of P2-type Na 0.67 Fe 0.5 Mn 0.5 O 2 for Mn 3+/4+ redox reactions is more than that of the O3-type NaFe 0.5 Mn 0.5 O 2 while it is less for Fe 3+/4+ redox reactions, because of structural transition. The diffusion coefficient of NaNi 0.5 Mn 0.5 O 2 is less for Ni 2+/4+ redox reaction and is up to the order of 10 −11 cm 2 s −1 .
Many attempts have been made to model and optimize performance parameters of Electrical Discharge... more Many attempts have been made to model and optimize performance parameters of Electrical Discharge Machining (EDM) process. In this investigation, the experimental design includes L9 orthogonal array based on the Taguchi methodology. The corresponding effect of input current, duty cycle and spark on time, on surface integrity, has been studied on AISI D2 tool steel. The residual stress measurement is done using X-ray diffraction method. The obtained output results regarding material removal rate, surface roughness, crack density, and residual stress have been modeled and optimized by regression equation and Genetic algorithm respectively. In this investigation, a metallurgical approach has been introduced towards the explanation of the resulted optimized response parameters.
Glass fibre reinforced plastics (GFRP) are having good weight to strength ratio, so they have wid... more Glass fibre reinforced plastics (GFRP) are having good weight to strength ratio, so they have wide range of application for
many purposes. Micro drilling of GFRP produces de-lamination in it. So it is always needed to optimize the process parameters
by minimizing thrust force and torque. The process parameters and response parameters values are used here for analysing and
optimizing the micro drilling of GFRP. The introduction of peck micro drilling in lieu of direct micro drilling was found to be
responsible for lower value of torque and thrust force. The optimized result of thrust force and torque was found to be 40000
and 5 of rpm and feed respectively for both direct and peck type of micro drilling.
Int. J Adv Trends Comput Sci Eng, Nov 29, 2013
Electro chemical machining is a non conventional machining process to machine conducting hard ma... more Electro chemical machining is a non conventional
machining process to machine conducting hard materials using
anodic dissolution. The process parameters are needed to be
optimized to get better result of material removal rate (MRR) and
surface roughness (SR). In this paper MRR and SR values are
optimized by Simulated Annealing (SA) and the effect of input
parameters are determined by Taguchi Design while machining
EN-19 tool steel.
Proc. of Int. Conf. on Emerging Trends in Engineering and Technology
Many attempts has been made to model performance parameters of EDM process using ANN. For modelin... more Many attempts has been made to model performance parameters of EDM process using ANN. For modeling generally ANN architectures, learning/training algorithms and nos. of hidden neurons are varied to achieve minimum error, but the variation is made in random manner. So here a full factorial design has been implemented to achieve the optimal of above. From the ANOVA result the significance order also has been decided. After that optimal process modeling of MRR in EDM with the best of above
parameter has been performed