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•Preparation of double perovskite La2CrMnO6 nanoparticles by auto-combustion route.•Preparation of La2CrMnO6/g-C3N4 nanocomposites by ultrasonic-assisted co-precipitation ...method.•Higher photodegradation yield due to synergistic effect between La2CrMnO6 and g-C3N4.•La2CrMnO6/g-C3N4 (80:20) nanocomposites showed 80.98 % removal of methyl orange (MO).•Photocatalytic mechanism in nanocomposite system for MO degradation was proposed.
Constructing semiconductor materials based on layered graphitic carbon nitride (g-C3N4) and metal oxides can help in extending the lifetime of charge carriers and aid in resolving the low number of active sites on their surface for light-driven processes. Herein, we initially designed La2CrMnO6 nanostructures through trimesic acid-assisted auto-combustion route and subsequently, La2CrMnO6/g-C3N4 nanocomposites were prepared by ultrasonic-assisted co-precipitation method with improved UV-catalytic performance. The shape, size distribution and various properties of nano-sized products were measured via diverse description systems of microscopic and spectroscopic. The photocatalytic performances of the La2CrMnO6 nanoparticles and La2CrMnO6/g-C3N4 nanocomposites were compared by degradation of artificial dyes under the UV-light region. Besides, the impacts of dye type, diverse weight percentages of g-C3N4:La2CrMnO6 in composite, scavenger kind and dye solution concentration were studied on modifying ability of nano-catalyst utility. The outcomes manifested La2CrMnO6/g-C3N4 (80:20) nanocomposites have the greatest efficiency, where the highest MO decomposition of 80.98 % was achieved at 10 ppm within 90 min of irradiation. Moreover, the feasible mechanism of MO elimination by UV catalytic purpose was considered.
Laser welding is used in critical component production when tight tolerances like minimal distortions and residual stresses are required. Laser beam welding offers a lower heat input, a smaller heat ...affected zone, lower residual stresses, minimum distortions, and greater mechanical joint characteristics than conventional welding does. In order to simulate the laser welding process used on SS316L plates, the Gaussian heat source model was used. The model is developed and simulated with volumetric heat source model with APDL coding using ANSYS. The thermal profiles at the joint cross sections via welded area, interface across joints is taken for the analysis. The maximum temperature was observed at the fusion zone and associated zones. The residual stresses are analysed in the same path and found the stresses are in safe limits of base material. Predicted and experimentally measured residual stresses are close agreement with 10%.
In recent research activities, autonomous vehicles and self-driving technology have gained lot of attention among scientists. The idea of autonomous vehicles can be anticipated in the 1920s when the ...design of the first radio-controlled vehicles was in progress. Autonomous vehicles are going to be the trend of the future in this modern era of automation and technology. In this paper various autonomous driving aspects, highlighting the software stack and hardware components are discussed. The software architecture covers mainly robot operating system (ROS), machine learning (ML), deep learning (DL), and OpenCV frameworks, along with the calibration of sensors and cameras. The paper also discussed about simultaneous localization and mapping (SLAM) based-path tracking, computer vision-based controller, and intelligent object avoidance. Further, point cloud, ground, radius, and raycast filters was implemented to distinguish between the real-time objects, ground, and its own parts or obstacle shadows. The paper highlights the overall hardware modules responsible for controlling the car.
•Future trend of Autonomous vehicles in modern era of automation and technology.•Simultaneous localization and mapping based-path tracking.•Computer vision-based controller, and intelligent object avoidance.•Discussion on Hardware modules responsible for controlling the car.
A thin film of Fe-CdZnS was fabricated using the Chemical Bath Deposition (CBD) procedure in an aqueous solution, which was then deposited onto a glass substrate. The resulting thin film was ...subjected to characterization using scanning electron microscopy (SEM), energy-dispersive Xray spectroscopy (EDX), Xray diffraction (XRD) for structural analysis, and UV–Visible spectrophotometry for optical investigations. The energy band gaps of the produced film were established by analyzing the UV–VIS absorption data, both in terms of direct and indirect transitions. According to XRD results, the film shows nano crystallinity with cubical structure. The presence of doping ions was confirmed by EDS results where ratio of Fe ions inside the CdZnS was equal to 0.3 from total elements. The (SEM) graphs of the Fe-CdZnS film exhibit a distinct leafy and fiber-like morphology when observed from a planar perspective. The direct and indirect bandgaps were calculated and found equal to 2.8 and 2.3 eV respectively.
Machining of titanium alloy grade V (Ti6Al4V) is very difficult by conventional metal cutting process due to low thermal conductivity, ability to retain strength at elevated temperature, tendency to ...work harden. This may result in high heat at the cutting zone and the generation of thermal stresses. Therefore, in the present research die-sinking electrical discharge machining is used to machine Ti6Al4v alloy. A non-dominated sorting genetic algorithm (NSGA II) coupled with rotary central composite design (RCCD) based on response surface methodology (RSM) is employed to optimize machining parameters in die-sinking electrical discharge (EDM) machining of Ti6Al4V. A quadratic mathematical model has been developed for material removal rate (MRR) and surface roughness (Ra) in terms of peak current (I), pulse on time (Ton) and pulse off time (Toff) as independent input parameters. Die-sinking EDM experiments are planned using RCCD based on response surface methodology. Results revealed that peak current is the most influencing EDM parameter on both MRR and Ra with PC of 35.86% and 57.10% respectively. MRR continuously increases with peak current. MRR firstly decreases and then increases with an increase in Ton. Ra continuously increases with peak current and starts decreasing after a coded value of 1.5. The Optimization result obtained by NSGA II is validated through confirmation experiments which are in good agreement with the experimental value with an absolute error of 6% and 4.8% in MRR and Ra respectively.
Geopolymer concrete (GPC) is an eco-friendly, sustainable, cementless and green concrete. It could be an alternative to the conventional concrete. In alkaline circumstances, the alumina and silica ...concentration in geopolymer concrete creates the geopolymer bond, while regular concrete creates C-S-H (calcium silicate hydrate bond). The final result of the geopolymer bond does not include any water. At elevated temperatures, geopolymer concrete would thus be more stable. Due to its greater strength and durability quality, geopolymer concrete may be the ideal replacement for ordinary portland cement (OPC) concrete. This research intends to examine how specimens of geopolymer concrete and regular concrete respond to exposure to increased temperatures between 100°C and 800°C. Mass loss, ultrasonic pulse velocity, compressive strength, X-ray diffraction, thermogravimetric analysis and derivative thermogravimetric analysis were all examined throughout the experimental examination. Both concrete specimens lose mass or weight as the exposure temperature rises; OPC concrete samples spalls at 600°C, while GPC sample fail at 800°C. GPC specimens lose around 12% of their original mass after being exposed to temperatures of 800°C, while OPC specimens lose about 7%. The GPC specimens maintained 60% of their initial compressive strength after being exposed to a temperature of 700°C, but the OPC concrete specimens only kept 52%. With each increase in exposure to extreme temperatures, the peaks of quartz and cristobalite are lowered. Only the form or structure of the mineral oxide would change; the chemical linkages would remain. The GPC samples subjected to temperatures of 100°C exhibit effective thermal stability than all other specimens exposed to extreme temperatures. As the exposure temperature rises, the GPC specimens become more thermally stable. According to the experimental findings, the GPC specimens’ bonding structure makes them more resistant to high temperatures than regular concrete specimens. Micropores are present in the voids of the geopolymer matrix, while mesopores and micropores are present in the voids of the OPC matrix. While OPC bonding is C-S-H formed by the hydration of lime and silica contained in the cement, the geopolymer bonding did not include the water content in the final or end result of geopolymerisation for strengthening.
Incorporating narrow band gap oxide semiconductors and metals into zinc oxide (ZnO) nanostructures broadens the range of light sensitivity to include visible wavelengths. In this study, the ...photocatalytic degradation of rhodamine B (RhB) dye was studied as a model for environmental pollution in aqueous media. This study describes the use of photodegradation catalysts, including gold (Au), ZnO, and Au–ZnO nanocomposites (prepared in ratios of 90:10 and 95:5) using the extract of Citrus medica leaves. X-ray diffraction (XRD) findings have shown that ZnO nanoparticles (NPs) have a hexagonal wurtzite structure. Field emission-scanning electron microscopy findings have depicted that ZnO NPs have diverse shapes, including spherical, quasi-spherical, hexagonal, and anisotropic, with some clumping. Au exhibits consistent spherical shapes and sizes with even distribution. Au–ZnO (90:10) shows quasi-spherical NPs with interconnected spherical Au, forming a porous and uneven surface. Au–ZnO (95:5) has spherical gold nanoparticles (Au NPs) dispersed on a textured ZnO surface, with some clustering and size variation as evident from the transmission electron microscopy, atomic force microscopy, and diffuse reflectance UV-visible spectroscopy analysis. The characterization results have demonstrated the uniform distribution of Au across the ZnO lattice. Additionally, the XRD patterns confirmed the hexagonal wurtzite structure of ZnO. Furthermore, energy-dispersive analysis of X-ray (EDX)-mapping verified the inclusion of zinc, oxygen, and Au in the hybrid Au–ZnO nanocomposites and their effective distribution. The topological analysis revealed a rough surface for the generated nanostructures. By comparing the results of various techniques, EDX analysis using atomic and weight ratios confirmed the presence of oxygen and Au in the nanocomposite. Additionally, the surface area analysis (BET) test has reported that the adsorption and desorption of nitrogen follow a Type III isotherm. The presence of an H3-type hysteresis loop further confirms the mesoporous nature of the composites, which reports the presence of wedge-shaped pores. The Au–ZnO (90:10) nanocomposite exhibits a higher surface roughness compared to other composites. In addition, this UV-visible diffuse reflectance spectroscopy has enumerated the band gaps of various nanomaterials using UV-visible spectroscopy. Moreover, the analysis has unveiled that combining ZnO with Au NPs (doping) improved the photocatalytic performance of ZnO. This improvement is attributed to the formation of additional energy levels within the ZnO band gap due to the presence of Au ions. Experimental investigation of the breakdown of RhB dye under visible light irradiation revealed superior photocatalytic activity for the Au–ZnO (90:10) nanocomposite compared to both Au–ZnO (95:5) and pure ZnO and Au counterparts. Multiple experiments confirmed the effective photodegradation and removal of RhB dye from the aqueous medium using the nanocatalyst under visible light irradiation. Under optimal conditions (1.0 g·L
photocatalyst, 10 ppm RhB, and pH 10), 99% photodegradation efficiency was reached within 50 min of irradiation. Investigation of reactive species revealed that the increased effectiveness of photodegradation in Au–ZnO (90:10) stems from the presence of photogenerated holes and hydroxyl radicals. The study also analyzed the reaction kinetics and order, and the reusability of the best photocatalyst Au–ZnO (90:10)) was confirmed through five consecutive cycles, demonstrating its sustained effectiveness in photodegradation. These findings highlight the potential of Au–ZnO (90:10) nanocomposite as a promising material for photocatalytic degradation of organic dyes.
This study explores the potential benefits of gas metal arc (GMA) welding for ASME SA387-Gr.11-Cl.2 steel, with a focus on ensuring humane and environmentally friendly welding techniques. Metal-cored ...filler wire (MCFW) was tested on 6 mm thick ASME SA387-Gr.11-Cl.2 steel plates using MEGAFIL 237 M. Current (A), voltage (V), and gas flow rate (GFR) were tuned to get optimal results during welding, which was performed at 100 A, 13 V, and 21 L/min, respectively. Subsequently, visual inspection confirmed the absence of surface defects in the as-welded plates. In addition, macroscopic metallography analysis confirmed the satisfactory weld bead geometry (WBG). Microstructural variations were analyzed using optical microscopy, and microhardness measurements were taken to validate the results. Furthermore, the as-welded plates were heat treated before being examined for microstructure and microhardness. Comparative analysis of microstructure and microhardness values showed that the weld zone of as-welded plates exhibited a lanky martensitic configuration, while the heat-treated plates demonstrated a finer and more irregular distribution of the unaltered martensitic structure. These findings were further supported by respective hardness values of 1887.4 HV and 262.4 HV for the as-welded and heat-treated plates. By exploring the optimized use of metal-cored filler wire in GMA welding for ASME SA387-Gr.11-Cl.2 steel, this research aims to achieve welding practices that meet both technical requirements and environmental considerations, ensuring a humane approach to welding processes.
The aim of the study was to improve the mechanical, biodegradation and in vitro biocompatible characteristics of as received rolled AZ31 (Mg-1%Zn-3%Al) alloy by develop the surface composite of ...Mg-Titania. The surface composite was developed by friction stir processing (FSP) and it's used for prosthetic applications. The influence of tool rotation speed and number of FSP passes on grain structure, grain refinement, tensile strength, hardness, in vitro degradation rate and in vitro biocompatibility were explored. The obtained results support the capability of FSP in terms of mechanical strengthening, refinement of grain structure, dispersion of reinforcement (i.e. TiO
2
) and controlled degradation rate. Grain structure at stir zone, advancing side and retreating side were investigated. The large grains in the alloy were reduced to a fine equiaxial grains of average dimension of
≈
3 μm by 3rd pass of FSP. The process was performed under two different tool rotation speed, i.e. 1550 and 2260 RPM. The addition of second phase in the matrix significantly improve the grain refinement. The results obtained from tensile test revealed the improvement in the percentage elongation without compromising the strength. The micro hardness of specimens of different parametric combination were evaluated and found
≈
30-50% improvement in the micro hardness. The degradation rate by immersion test in simulated body fluid (SBF) for 3, 6 and 10 days were performed and found a significant reduction in degradation rate. The MTT assay for the biocompatibility performed by indirect method, the results validate the non-toxic behavior of processed specimen.
Despite the introduction of different semiconductor photocatalysts for removing a variety of colors and contaminants, the development of novel multi-component substances with strong light-harvesting ...capacity remains a challenge. The purpose of this paper is to rationally design binary CeO2/MnCr2O4 heterostructure nanocomposites through the green sol-gel self-combustion route and use them as visible light-active nano-photocatalysts in wastewater treatment. Several physicochemical instruments, including powder X-ray diffraction (XRD), Energy Dispersive X-Ray Spectroscopy (EDS), and Field Emission Scanning Electron Microscopy (FESEM), were used to examine the effects of banana juice volume on crystal structure, purity, and shape of as-formed specimens. Optical results demonstrate that binary CeO2/MnCr2O4 nanocomposites have high photocatalytic activity due to their 2.9 eV band gap. As a result of using 10 mL of banana juice, the best performing product removed almost 84 % and 93 % of methyl orange (MO) in 90 minutes and 120 minutes, respectively, under visible and UV light. CeO2/MnCr2O4 nanocomposite is a promising candidate for photocatalysis according to these findings.
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