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The current study aims to explore the impact of friction stir welding (FSW) parameters on the tensile strength of dissimilar joint materials. A copper grade CDA 101 and an AISI-SAE low-carbon steel grade 1010 were selected as the dissimilar materials to analyze the tensile strength of the weld joints. The axial force, tool rotational speed, and welding speed were selected as process parameters for the weld joint fabrication process. The influence of the process constraints was investigated using the Taguchi technique, which is based on the L9 orthogonal array. Investigation of variance and signal-to-noise ratio were considered to forecast the ideal welding process constraints, and their percentage of contribution was computed by comparing the anticipated and actual welding process parameters. The test results revealed that the speed of the tool and the downward force (axial) exerted on the joint played a substantial impact on the joint strength. The maximum tensile strength of the Cu-steel dissimilar weld joints is found as 189 MPa which is determined during optimal welding process parameter values having tool rotating speed of 1100 rpm, welding speed of 40 mm/min, and an axial force of 6 kN. The FSW joints were inspected under a scanning electron microscope (SEM) and with an EDAX to identify the micro patterns and fracture surface of the joints. [ABSTRACT FROM AUTHOR]

Polycrystalline silicon (p-Si) is essential for semiconductor and photovoltaic industries due to its cost-effectiveness, efficiency in solar cells, and versatile applications in electronics. This research investigation synthesized and evaluated the functional characteristics of polycrystalline silicon (p-Si) layer featuring varied thicknesses of silicon nitride (SiNx) coating via plasma enhanced chemical vapour deposition (PECVD). This study explores how SiNx texturing layers with various thicknesses affect the optical and electronic properties of the underlying p-Si substrate. It confirms that SiNx passivation layers are crucial in improving the efficiency of p-Si-based devices by reducing surface recombination velocities, improving solar efficiency, and enhancing light trapping. The effect of SiNx coating thickness on the structural, optical, and electrical behaviour of p-Si is studied. The p-Si featured with 30 nm is good transmittance (65%), improved band gap (1.55 eV), better I-V performance, optimum absorption current (1.6 X 10–4 mA/cm2), and improved quantum efficiency (86%), which is suitable making solar cell applications. [ABSTRACT FROM AUTHOR]

Aluminum alloys have gained widespread attention in various engineering sectors such as aerospace, automobile, and construction industries owing to their attractive properties. On the other hand, the tribological properties of aluminum alloys are of serious concern due to their limitation in terms of hardness. The objective of the current study was to enhance the surface mechanical properties including microhardness, compressive residual stress (CRS), and wear resistance of 7075-T651 aluminum alloy subjected to ultrasonic shot peening (USP). The samples of aluminum alloy were first treated with USP for various durations followed by different types of in-depth characterization. X-ray diffraction analysis was used to examine the bulk texture development after peening. The wear studies were carried out on a ball-on-plate wear testing machine under various applied loads. The results indicated an increase in hardness, surface roughness, and CRS of the samples with increasing USP time. Additionally, a marginal difference in the surface roughness of peened samples was observed for selected peening times. The wear depth and width of peened wear tracks were found to be less than those of un-peened ones. The surface tribological properties of the worn-out samples were studied using scanning electron microscopy (SEM). The elemental analysis was carried out using electron-dispersive spectroscopy (EDS). [ABSTRACT FROM AUTHOR]

In the modern era, various engineering applications utilize renewable solar energy, and recent prospects aim to enhance solar thermal collector efficiency through nanotechnology found to enhance solar performance. While using the parabolic trough collector, it found excellent solar conversion efficiency and attained the maximum temperature of the working fluid. Besides the intermittency due to weather conditions, the output performance will be reduced. This study aims to enhance the performance of parabolic trough solar collector by implementing magnesium oxide (MgO) coating over the tubes as 30, 20, and 10 µm particles blended with industrial black matt paint to prepare MgO-enhanced coating through the spray pyrolysis process for varying the nanoparticle size with constant thickness coating in the thermal performance of parabolic trough solar collector (PTC). The findings of this research demonstrate that particles with coating material significantly affect the thermal performance of PTC compared with non-coating. The 10 µm MgO coating featured solar collector exploited maximum heat transfer fluid temperature (81.2 °C), increased heat absorption behaviour (662.5 W), optimum thermal and exergy efficiency values of 78.9 and 69.5%, respectively, which is the optimum value rather than all others. [ABSTRACT FROM AUTHOR]

Most of the efficient organic solar cells (OSC) often utilize reactive low-work-function metals like calcium and LiF as a buffer layer. Over a period of time, these types of buffer layer degrade, reacts and diffuses into electrode, photoactive layer. These type of changes results in reduction in efficiency and less lifetime of the OSC. This work demonstrated fabrication of OSC with ionic conducting non-conjugated polyelectrolytes polyethyleneimine (PEI) and perfluorinated ionomer (PFI) instead of conventional transport layer. PEI and PFI were used as a cathode and anode buffer, respectively, in the following device configuration ITO/PEI/P3HT:PC61BM/PFI/Ag. For various PFI thickness, OSC efficiency was optimized. The highest efficiency of 1.82% was obtained for 1:15 PFI ratio device, which was significant improvement than the reference device without PFI. The obtained results were analyzed and critical changes were discussed in this work. [ABSTRACT FROM AUTHOR]

Casting of aluminum with different concentration of alloying elements such as Mg, Mn (similar to that in AA5083) with additional percentages of 0.1, 0.2 and 0.3% Ti, are carried out using graphite crucible. The as-cast microstructure is modified by hot rolling to a thickness of ~ 2 mm. Mechanical and metallurgical and characterization of heat-treated thin sheets are carried out using tensile testing, hardness measurement, metallography, image analysis and optical microscope. By increasing the Ti content, the results show grain refinement and increase in the formation of Al3Ti which reflected positively on the mechanical properties. Specifically, Ultimate tensile strength is increased from 260 MPa (0 wt% Ti) to 345 MPa (0.3 wt% Ti) when using water quenching, 32.6% improvement for air cooling, and 23.3% for furnace cooling. Electrochemical corrosion behavior of heat-treated water quenched, air cooled and furnace cooled samples were tested in 3.5% NaCl solution. The results show that the heat-treated alloys have very good resistance against corrosion, while by increasing the Ti content, the corrosion rate increases due to the grain refinement phenomena. [ABSTRACT FROM AUTHOR]

The present study deals with the fabrication of Al–ZrC nanocomposite prepared by varying the reinforcement content in wt% via spark plasma sintering. The grain size exhibited in bulk product was 13 μm in 12 wt% ZrC reinforced nanocomposites. The introduced ZrC nanoparticles were upgraded the load carrying ability of the end product. The advanced microscopic studies such as XRD, SEM and TEM were analysed to study the structural behaviour. The XRD results revealed the presence of ZrC in the Al matrix; SEM expresses the constant scattering and non-appearance of agglomeration among the ZrC particles; TEM results depicted the clear interface between the matrix and reinforcement. The hardness and compression studies were carried out in the fabricated nanocomposites. The obtained results confirmed that the nanocomposites exhibited better outstanding load carrying ability which was due to decrease in grain size, uniform dispersion of reinforcement particles and generation of dislocation due to thermal mismatch between Al and ZrC. [ABSTRACT FROM AUTHOR]

α -vanadium pentoxide (α-V2O5) thin films with the orthorhombic crystal structure were successfully grown on Si-substrates using pulsed laser deposition (PLD) technique with varying substrate temperatures. XRD spectra confirm the formation of orthorhombic V2O5 phase which is evident as the strongest peak at ~ 20.38°. The films are apparently crystalline in nature, and the average crystallite size ranges between ~ 200 nm–~ 400 as obtained from Scherrer's equation. FESEM image shows the films as compact nanostructured type displaying a globular (at 500 °C) or sheath like morphology (at 600 °C and 700 °C). AFM study shows that the average surface roughness of V2O5 films increases with increasing substrate temperature. UV–vis spectroscopy shows that the fundamental absorption edge has shifted to the red side (higher wavelength) with increasing temperature. Optical band gap values (Eg) decrease with increasing deposition temperature (at 700 °C, Eg ~ 2.08 eV). [ABSTRACT FROM AUTHOR]

The thermal analysis on hydromagnetic two-dimensional flow of dusty nano fluid along an upper horizontal surface of paraboloid revolution have been scrutinized. The governing flow are derived under the assumptions of Boussinesq's boundary layer approximation theory. The effects of Cattaneo-Christov heat flux, variable thermal conductivity, joule heating and viscous dissipation are incorporated in the energy equation. The governing PDE's for the flow and energy transfer for both the phases are transformed into ODE'S by employing the suitable similarity transformations. The final dimensionless governing coupled ordinary differential equations are resolved with the aid of bvp5c procedure in computational Matlab software. The effects of dimensionless governing controlled flow parameters on velocity, micropolar velocity, and temperature profiles for both the phases are reported and discussed elaborately through plots and tables. The emerging three nanoparticles namely gold, silver and platinum ( A u , A g and Pt ) are considered throughout graphical analysis along with H 2 O is used as a base liquid. It is revealed that the flow velocity declined for strengthen of the applied magneticfield. It is worthy note that the larger values of thermal relaxation parameter γ declines the fluid temperature for both phases. Also, the rate of heat transfer is an increasing function to the escalating values of variable thermal conductivity ε , while it is reverse trend for the thermal relaxation parameter γ . The observations exhibit the prominent features in the field of an advanced bio-medical and thermal engineering. [ABSTRACT FROM AUTHOR]

Steel structures significantly degrades owing to corrosion especially in coastal and industrial areas where significant amounts of aggressive ions are present. Therefore, anodic metals such as Al and Zn are used to protect steel. In the present study, we provide insights for the corrosion mechanism and kinetics of Al-Zn pseudo alloy coating deposited on mild steel plate via an arc thermal spraying process in 3.5 wt.% NaCl solution in terms of its improved corrosion resistance properties at prolonged exposure durations. Electrochemical studies including open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) on the deposited coating at longer exposure durations revealed enhanced corrosion resistance properties while the morphology of corrosion products through field emission-scanning electron microscopy (FE-SEM) indicated their compactness and adherence. Furthermore, atomic force microscopy (AFM) confirmed reduced roughness when compared with that of unexposed coating. Additionally, X-ray diffraction (XRD) and Raman spectroscopy results confirmed the formation of protective, adherent, and sparingly soluble Simonkolleite (Zn5(OH)8Cl2.H2O) after 55 d of exposure in 3.5 wt.% NaCl solution. A schematic is proposed that explains the corrosion process of Al-Zn pseudo alloy coating in 3.5 wt.% NaCl solution from the deposition of coating and initiation of corrosion to longer exposure durations. [ABSTRACT FROM AUTHOR]