Pandit Deendayal Petroleum University

About: Pandit Deendayal Petroleum University is a education organization based out in Gandhinagar, Gujarat, India. It is known for research contribution in the topics: Welding & Computer science. The organization has 996 authors who have published 1804 publications receiving 16594 citations.

Impedance Analysis of Inherently Redox-Active Ionic-Liquid-Based Photoelectrochemical Cells: Charge-Transfer Mechanism in the Presence of an Additional Redox Couple

Abstract: An intensive electrochemical impedance study was carried out to understand the charge-transfer processes in photoelectrochemical (PEC) cells based on ionic liquid (IL) electrolytes. Three different electrolytes were utilized to understand the role of redox species as well as the medium on the charge-transfer mechanism. The negligible diffusion resistance, despite the presence of two different redox species in the case of Fe(CN)(6) (-4/-3) in IL, was explained on the basis of charge transfer between species of two different redox couples. Accordingly, the redox species are not required to travel through the bulk of the electrolyte for the removal of accumulated charges, as short-range charge transfer between the IL and the Fe(CN)(6) (-4/-3) species facilitates the removal of accumulated charges. It is also shown that PEC cells utilizing dual redox couples are highly stable with larger photoelectrochmeical windows, >3 V.

Enhanced electrocatalytic performance of Mo–Ni encapsulated in onion-like carbon nano-capsules

Abstract: Core–shell-structured nano-capsules consisting of Mo–Ni nano-particle as core and onion-like carbon shell are synthesized using arc-discharge method followed by an air-annealing process. The XRD patterns have ascertained the formation of nickel metal with different planes in fcc and hcp form with the formation of MoO2, MoNi4, and NiMoO4 phases. The BET surface area values gradually decreased with greater encapsulation of nickel whereas the electrochemically active surface area (ECSA) values have been calculated as quite higher. Electrocatalytic activity has been evaluated in HER and OER during water electrolysis for PEM water electrolyzer. These materials have been proved as far better candidate in cyclic voltammograms than those of pure carbon hollow spheres.

Comparisons of Different Oxide Fluxes in Activated Gas Tungsten Arc Welding of Duplex Stainless Steels for Improved Depth of Penetration and Pitting Corrosion Resistance

Abstract: The present work analyses the effect of five types of oxide fluxes – SiO2, TiO2, CrO3, MnO2 and MoO3 – on the depth of penetration and pitting corrosion behaviour of UNS S32205 duplex stainless ste...

Dual BEM for wave scattering by an H-type porous barrier with nonlinear pressure drop

Abstract: In this paper, wave scattering by an H-type porous barrier having nonlinear pressure drop boundary condition is analysed within the framework of small amplitude water wave theory. The H-type barrier is constructed using multiple thin (near zero thickness) rigid porous plates which are termed degenerate boundaries. The boundary value problem is solved using an iterative dual boundary element method. Different barrier configurations are analysed and compared to demonstrate the improved hydrodynamic performance of the H-type barrier. Further, the effect of porosity, relative spacing, the relative depth of submergence of the horizontal plate, wave steepness, and the rotation of the horizontal plate is investigated parametrically. Several results such as scattering coefficients (reflection, transmission, and energy-loss) and force coefficients (horizontal, vertical, and moment) are presented to understand the feasibility of the H-type barrier in real field applications. It is revealed that the increase in the structure porosity consistently increases the wave transmission, but reduces wave reflection, and force coefficients. Further, an increase in the relative spacing between the vertical barriers reduces the wave transmission by 20% without increasing the horizontal wave force but at the expense of increasing the vertical force coefficient in the shallow water regime. The results of this study are expected to be useful for the appropriate selection of different structure parameters to optimize the design.

Articulating effect of low copper content on structure and optoelectronic properties of spray deposited Cu2ZnSnS4 thin films – From experiment and first-principles investigations

Abstract: Improvement in the efficiency of truly inexpensive spray-pyrolysed Cu2ZnSnS4 (CZTS) thin film solar cells demands both the minimal presence of secondary phases as well as low carrier concentration. The present work deals with a strategy to obtain high quality spray pyrolysed CZTS films with low carrier concentration by controlling Cu-precursor concentration ([Cu2+]). By reducing [Cu2+] from 0.0136 M to 0.0129 M, film’s microstrain changes from compressive (1.76 × 10−3) to tensile (5.89 × 10−3) in nature, allowing the suppression of secondary phase formation. At an optimally low [Cu2+] of 0.0122 M the film shows pure phase, a lower tensile strain and a free carrier concentration of 3 × 1018 cm−3 with p-type conductivity and a high mobility of 3.22 cm2/Vs. Interfacial charge transfer is also promoted in this condition which is verified from electrochemical impedance spectroscopy. Moreover, the consequence of the modulation in the electrical properties through precursor [Cu2+] on the electronic structure and its optical absorption properties are corroborated from first-principles calculation.