CdS-based nanostructures have recently gained a lot of curiosity in photocatalyst study. Significant progress has been made in solar-fuel conversion and environmental refining in terms of CdS. This paper includes a detailed overview of the design strategies used for CdS-based nanostructured photocatalysts to increase the efficiency of H2 evolution. Despite tremendous development in recent years, there are still various challenges, with an overall understanding of the process for improving H2 reported. Various approaches were developed to improve the generation of photocatalytic H2 using CdS-based nanostructures. These include multi-component solid solution development, cocatalyst doping, Z-scheme heterostructure construction, multifaceted nanostructure development, and photo-corrosion reduction. CdS photocatalysts with higher visible light absorption, redox capacity, and load separation efficiencies may be created. The longevity and homogeneity of photocatalysts remain key challenges that must be tackled in the long term. In brief, researching novel approaches for enhancing the general effectiveness and usefulness of CdS-based nanomaterials may open up new paths for the efficient use of solar energy to generate hydrogen fuel.

This investigation focuses on the fully reversed flexural fatigue bending for Ti-6Al-4V thin-wall specimens fabricated by the laser powder bed fusion (LPBF) process. The experimental campaign documents the number of cycles to failure (Nf) for thin-wall design thicknesses ranging from 0.1 mm to 0.4 mm under mill annealed (MA) and hot isostatic pressing (HIP) conditions. The examined variables were microstructure, porosity, surface roughness, and the presence of tungsten particles. For the tested conditions, the thin-walled specimen with thicknesses from 0.1 mm to 0.3 mm experienced low cycle fatigue (LCF), while the 0.3 mm and 0.4 mm thickness samples experienced ultra-low cycle fatigue (ULCF). The results demonstrate that a combination of porosity present near or at the surface and surface roughness forming notches drives fracture initiation. The micro-void coalescence was found to explain the deformation mechanisms under high-strain cyclic loading. A machine learning model was developed to correlate the contribution of the thin-wall thickness, distance of pore center to surface boundary, Δε, and fracture pore √("area" ) with the fatigue life.

The need for energy in industries is growing daily, with space heating and process applications appearing to be the main uses of energy. Solar technology, especially air collector, contribute a lot in meeting these energy demands and are widely being used for various applications. Any improvement in the performance of such collectors will contribute a lot in terms of energy that is conserved. Solar air collector generally comprises of rectangular cross section having two separate sections having upper and lower section in which upper portion is exposed to solar radiation. The study's findings show that rectangular channel of the upper surface is made efficient by adding artificial roughness on it which is used to increase the heat transfer coefficient of the flowing fluid as well as improve the overall performance of the system. The configuration with artificial roughness shows a remarkable enhancement in terms of thermal performance showing a maximum improvement over the plain configuration.

In this study, both experimental and numerical methods to analyse the transient surface temperature and convective heat flux on a quartz-based conical body with laboratory-fabricated platinum thin-film gauges (film thickness 0.1–1.0 µm on 6 mm Ø × 10 mm quartz substrates) is carried out. During fabrication, platinum paste is dried at 650 °C and silver contacts at 350 °C, yielding a gauge resistance of 4–8 Ω and a measured temperature coefficient of resistance (TCR) of 0.02727 K⁻¹. Additionally, the work covers the dynamic calibration at a steady 10 mA current is supplied to each gauge while high-speed air at 318 K and velocities of 3–5 m/s impinged on the cone for 1 s. Transient temperature histories (300.0–300.7 K) are recorded at 0.01 ms intervals and processed via a one-dimensional semi-infinite conduction model to recover surface heat flux. Numerical simulations in ANSYS Fluent, employing a standard k-ε turbulence model with 0.01 ms time steps (100 steps) and adiabatic, no-slip boundary conditions, reproduced the same flow and thermal conditions. Experimental and numerical heat-flux signals exhibited excellent agreement (maximum convective heat flux ≈ 8 kW/m² at the stagnation point, with deviations < 5%), thereby validating the cost-effective gauge fabrication and calibration methodology and demonstrating its suitability for millisecond-scale surface-heat-flux measurements.

CuBi2O4, or copper bismuth oxide, is the most important spinel oxide and a promising material that shows its excellent potential in photocatalytic applications. As titanium dioxide (TiO2) is a widely used photocatalyst that absorbs UV light, CuBi2O4 absorbs visible light too because of its narrower band gap energy (1.5-1.8) eV, and this makes it much efficient in various applications, as UV light is not widespread. CuBi2O4 is also used as a photoelectrode material for photoelectrochemical (PEC) cells. In addition to photocatalysis, it is specifically used as an electrode material in batteries as its structural stability and good capacity make it suitable for effective charge storage and long-term cycling. Recent advances in the synthesis of CuBi2O4 from the hydrothermal method, sol-gel method, co-precipitation, etc., have enhanced its production with improved surface areas and engineered morphologies, hence improving its performance in storing energy. CuBi2O4 also forms heterojunctions with perovskites and photocatalysts (such as SrTiO3, TiO2, ZnO etc.), which enhance its photocurrent density and photostability, but it is quite challenging. Hence, this review highlights the CuBi2O4-based materials, with their synthesis methods and applications in the photoelectrochemical H2O splitting for H2 generation, CO2 reduction, solar cells, and batteries that describe their importance in producing energy.

This study investigates the tool wear for turning Inconel-718 using the titanium nitride carbide tool inserts. This research work aims to compare the performance of processed images and acoustic waves used as an indirect technique for evaluating tool wear. The work targets to capture the tool wear and tool image after turning and acoustic wave during turning for each experimental run. The pixel area of the processed picture, the root-mean-square (RMS) of the acoustic wave, and the microscope tool wear of the tool maker were taken into consideration as output parameters for the change of operational parameters including feed, speed, and depth of cut. The performance of wear, pixel area, and RMS was compared using the Box Behnken method. Further, the correlation between the performance of tool wear, image processed pixel area, and RMS for the variation in input variable was obtained from interaction and main effects plots. The results demonstrated that at lower speeds (280rpm), lower feed rates (0.04mm/rev), and medium depth of cut (0.2mm), there was less wear, pixel area, and RMS. Wear, pixel area, and RMS have all decreased as a result of the tool and workpiece having less surface friction due to the reduced speed, feed, and medium depth of cut. From the analysis, it was also clear that the indirect evaluation of the wear can be successfully carried out using digital image pixel area and acoustic wave RMS for turning Inconel-718 using a titanium nitride-coated carbide tool.

The whole world is facing a serious freshwater crisis as the existing sources are rapidly depleting. There is an urgent need to explore a new and sustainable source of potable water to meet the current demand. Solar-powered atmospheric water harvesting (SP-AWH) is an innovative approach to extract water vapor from ambient air as drinking water. Most of the SP-AWH system available in the literature are based on desiccant bed & flat plate collector. These systems are facing limited adsorption capacity of desiccant bed and lower efficiency of flat plate collectors. The present system uses a desiccant wheel for adsorption, an evacuated tube solar air heater for the regeneration of desiccant wheel, and an air-to-air heat exchanger for the condensation of water vapor. The system is operated daily for seven consecutive days under various ambient and operating conditions. The investigation shows that the increase in DBT of ambient air and decrease in humidity ratio severely affected the performance of the SP-AWH system. Under the ambient conditions (i.e. 36 degrees C DBT and 20 g/kgda humidity ratio) and operating condition (i.e.113 degrees C regeneration temperature and 144 kg/h air flow rate) this system achieved a water productivity of 8.6 L in a day. Further, by increasing the regeneration air temperature by 10% the system's daily yield reaches 9.55 L in a day. Increasing the process air flow rate from 144 kg/h to 180 kg/h improved the water productivity to 10.34 L in a day with an energy efficiency of 10.2 %.

This study reports the change in microstructure and microhardness occurring during solution heat treatment of a support-free zero-degree IN625 overhang processed using laser powder bed fusion. In as-built condition, the bulk section consisted of fine cellular structure (0.7 ± 0.2 µm) with Nb segregation and a dislocation density of 1.34 × 1014 m−2. In contrast, the downskin displayed a coarser solidification structure of 4.7 ± 2.1 µm and a lower dislocation density of 0.74 × 1014 m−2. This structural variation resulted hardness gradient ranging from 322 ± 17 HV in the bulk to 278 ± 18 HV in the downskin. After solution treatment (ST), the bulk region exhibited recrystallization and grain growth, while the downskin experienced limited grain growth, which is explained by the smaller stored strained energy in the latter. The microhardness gradient was reversed, where the bulk has a lower hardness than the downskin (252 ± 15 vs 271 ± 10 HV). The lower hardness for the bulk is associated with recrystallization, while the similar value in hardness for the downskin was ascribed to an equivalent change in the strengthening contribution from cell-boundary strengthening to Orowan dispersion strengthening.

Support-free IN625 overhang bars (60 x 10 x 7 mm3) were successfully fabricated using laser powder bed fusion (LPBF), achieving a minimum overhang angle of 5 degrees at 30 mu m layer thickness and 10 degrees at 60 mu m layer thickness. Supported bars were also fabricated to conduct a systematic comparison. Residual stress analysis revealed an increase in residual stresses with decreasing overhang angles. The downskin surface topography exhibited pronounced stair-stepping effects and powder adhesion, especially at low angles. Microstructural characterization confirmed columnar grains spread through the bulk region and small equiaxed grains in the downskin region of the low-overhang angle bars. While the primary dendrite arm spacing remained consistent within the bulk, it increased in the downskin region due to reduced heat dissipation. Correspondingly, the micro-hardness remains consistent in the bulk region, it decreases in the downskin region for the overhang angles below 30 degrees. Uniaxialtensile tests demonstrate consistent strength, while elongation is higher for increased overhang angle.

Healthcare has undergone a revolution due to bio-implants, which provide treatment for many fields of medicine. This paper aims to offer an assessment of the materials frequently used in bio-implant applications to support informed decision-making for better patient outcomes. The present study mainly focused on metal materials used as for bio-implant applications. This study proposes a framework for selecting the best material among different metallic materials for bio-implant applications that can be fabricated by metal additive manufacturing. Based on literature reviews and expert discussions, 19 factors were identified as important when selecting bio-implants. An integrated hybrid multi-criteria decision-making (MCDM) method, i.e., “step-by-step weight assessment ratio assessment” (SWARA) and “weighted aggregated sum product assessment” (WASPAS), is used to rank and select the most appropriate material for the bio-implant applications. The study identified titanium-based alloys as the best alternative among six metal materials, followed by cobalt-based alloys and stainless steel. The research outcomes give guidelines to researchers, policymakers, and healthcare professionals about the material selection criteria and ranking of the best materials for bio-implant applications.

The scarcity of freshwater resources is a growing challenge to sustainable development. Among the emerging solutions, humidification-dehumidification (HDH) technology has proven to be an economical and effective method for freshwater generation. In HDH systems the choice of packing materials in the humidifier significantly impacts the heat and mass transfer efficiency between air and seawater. This study explores the novelty of utilizing three distinct packing materials, namely jute fibre, coconut fibre matrix, and cellulose pad in a solar- based humidification-dehumidification desalination system. The system's performance is experimentally evaluated through thermo-economic and sustainability assessments at three airflow rates. Results show that the cellulose pad exhibits the highest specific humidity of air, resulting in the 16.8 kg/day of freshwater having 33% of overall energy efficiency at an airflow rate of 125 kg/h. This is followed by the coconut fibre matrix (15.3 kg/ day and 30.2 %, respectively), which outperforms the jute fibre (13.9 kg/day and 27.4%, respectively) due to its uniform flow distribution and larger specific surface area. The economic assessment reveals that the cellulose pad, coconut fibre matrix and jute fibre provide freshwater at a cost of 0.020, 0.022 and 0.023 $/L, respectively. The study highlights that coconut fibre, with its honeycomb-like structure, and jute fibre are cost-effective, environmentally sustainable, and locally accessible in coastal regions, making them viable alternatives for HDH systems.

The photovoltaic thermal systems can concurrently produce electricity and thermal energy while maintaining a relatively low module temperature. The phase change material (PCM) can be utilized as an intermediate thermal energy storage medium in photovoltaic thermal systems. In this work, an investigation based on an experimental study on a hybrid photovoltaic thermal (PV/T) system with phase change material has been carried out under the weather condition of north India to compare its output with a standalone photovoltaic system. The organic phase change material (melting point range 37 °C to 42 °C) was utilized to store thermal energy on the backside of the photovoltaic module. A sheet and tube type absorber was constructed with a spiral-shaped cooling water circulation channel within a PCM container to extract the stored heat. The energy and exergy-based analyses were performed to evaluate the performance of the PV/T PCM system in comparison to the regular PV module. A maximum reduction of 27

This paper reports on a computational study about the impact of fiber dipole orientation on particle collection efficiency of a bipolarly charged filter. The simulations were carried out using ANSYS software in a series of 2-D geometries comprised of randomly distributed fibers. The simulations were enhanced with in-house subroutines to incorporate Coulomb and dielectrophoretic forces in calculating particle trajectories and thereby simulating filter efficiency. The highest and lowest efficiencies were observed for dipole orientations that were perpendicular and parallel to the airflow direction, respectively. The simulation results were also compared with the predictions of the popular semi-empirical correlations from the literature and good general agreement was observed, without the need for any empirical correction factors. In addition, it was observed that the predictions of the semi-empirical correlations better agreed with the simulation results obtained for media comprised of fibers with random dipole orientations when challenged with neutralized particles.

The coating materials, thickness and number of layers directly influence the reflectance and absorptance properties of the thin films. However, while selecting the materials for single and coatings, the substrate’s refractive index; bond layer, functional layer and protective layer have to be carefully chosen to obtain the desired reflectance and absorptance values. Hence, modelling and simulating the thin film coatings is essential before conducting the experiments to get meaningful results. The simulation results of single coatings have been discussed. Generally, glass is one of the widely used substrate materials for solar reflectors, aluminum is the optimal functional material, with a reflection of 93 % of light. Nickel would be a preferable functional layer with a reflection of 64 % and absorptance of 36 %, Si3N4 being the acceptable bond layers and protective layers with a reflection of 68 % some solar thermal receiver tube applications however research effort is being made to find alternate lightweight materials for this application. Polycarbonate has been chosen as an alternate material for the substrate because it is light in weight with a reflection of 93 %, which is durable and not fragile.

A numerical investigation of the Nusselt number, heat transfer augmentation efficiency, and friction factor in a laminar flow tube with triangular perforated nail head twisted tape (TPNHTT) is reported using ANSYS 19.2 Fluent. The effects of triangular cut (each side 3 mm) in the middle pitch of the tape along the height, diameter, and top diameter of the nail head (10, 2, and 2.5 mm, respectively) have been explored for (300 <= Re <= 1800) in a tube of 22 mm diameter. In this paper, implementation has been done with a TPNHTT varying width (14 <= b <= 20) twist ratio (TR) ranging from (3 <= TR <= 6), inserts in a tube for laminar flow. Twisted tape (TT) produces a swirl flow associated with fluid resulting in heat transfer enhancement and pressure drop characteristics other than that for the plain tube (PT). The performance of the Nusselt number and friction factor increased up to 123.62% and 495.30%, respectively, on the application of TPNHTT as compared with PT. A maximum thermal performance efficiency of 2.98 has been achieved using the twisted-tape ratio of the current tube in laminar flow at a Reynolds number of 1700. In addition, correlation equations (11) and (12) have been developed for the friction factor and Nusselt number valid for 300 <= Re <= 1800, 14 <= b <= 20, and 3 <= TR <= 6. The study has proved that applying TT is an upgraded approach for laminar convection heat transfer. This novel work finding will be supportive for researchers to design the latest heat exchangers.

This study reports the fabrication and characterization of molybdenum (Mo) metal and titanium‐zirconium‐molybdenum (TZM) alloy exoskeletons with honeycomb cavity structures (HCS) that are infiltrated with oxygen‐free high conductivity (OFHC) Cu under an inert atmosphere as a potential replacement for Cu‐Mo‐Cu laminate in heat sink applications for power electronics semiconductors like GaAs. The thermal expansion behavior and the thermal loading of the starting Mo and TZM structures, and of the Cu‐infiltrated parts are evaluated. The fabricated Mo and TZM structures with density >99% and Mo‐based heat sinks with improved CTE (6.6 × 10 −6 K −1 ) when compared to conventional Cu‐Mo‐Cu laminated heat sinks (CTE = 7.6 × 10 −6 K −1 ). The new Mo and TZM structures promise superior performance due to their closer CTE to that of GaAs and similar semiconductors (CTE = 5.7 × 10 −6 K −1 ). Exposure to temperatures up to 1073 K did not affect the Mo microstructure due to the inherent resistance to recrystallization, while exposure to 1373 K did reduce hardness. In contrast, TZM exoskeletons showed resistance to recrystallization even at 1373 K. The fabricated composite heat sinks showed thermal diffusivity (≈61 × 10 6 m 2 s −1 ) that is within the upper limits of those reported for commercial laminated heat sinks (45 to 65 × 10 6 m 2 s −1 ).

Laser-directed energy deposition (LDED) is a newer way of making things that builds solid parts from metallic powder one layer at a time. The LDED process is more convenient compared to other metals synthesis processes because of its own merits such as minimum building time and greater powder deposition rate. The directed energy deposition machines can be programmed to use a specialized set of settings to process various grades of metallic powder. This process is mostly used for repairing metallic components. Inconel 718 is a superalloy used in high-temperature applications. In the present study, the LDED technique is used to synthesize the Inconel 718 superalloy. The experimental investigation examines the influence of powder feed rate and laser energy density on the geometry and quality of the single tracks deposition of Inconel 718 superalloy.

The solar air heater’s thermal efficiency is relatively poor owing to the flat collector surface. This article’s primary objective is to increase the collectors’ thermal efficiency of rectangular ducts of solar air heater by adopting a novel V-shaped twisted rib element with staggering orientation. Experimentations are performed for various flow Reynolds numbers ranging from 3 k to 21 k, roughness pitch-to-rib height ratio ranging from 7 to 11, and staggering distance-to-rib height ratio between 2 and 6. Dispersion of Nusselt number over the collector surface is achieved through the liquid crystal thermography technique. Among the varied rib and flow constraints, it is observed that a maximum thermal performance enhancement index of 2.69 is observed, with the optimum value of the roughness parameter at a rib pitch-to-height ratio of 9 and a staggering distance-to-height ratio of 4. Mathematical correlation has also been developed using a regression model to estimate the Nusselt number in terms of non-dimensional roughness parameters. The percentage deviation between the Nusselt number attained from established relationships and the investigational results is found to be giving very satisfactory outcomes. The thermal efficiency of the smooth surface is recognized at 41.64% which increases for the roughened surface of twisted V-ribs to 73.63%. Hence employing twisted V-ribs as an artificial roughness element no doubt increases the Nusselt number, thermohydraulic performance enhancement index, and thermal efficiency, but it also exerts less frictional power of solar air heater.

This study investigates a novel methodology to intricately craft a HAMMC and thoroughly examine its multifaceted mechanical and tribological characteristics. By combining silicon carbide (SiC) and fly ash as reinforcements, a unique identity is bestowed upon this hybrid composite, enhancing its structural integrity and functional attributes. Stir casting is the chosen methodology for fabricating this composite, favored for its economic viability and suitability for large-scale manufacturing. In this research, the emphasis is on developing a cost-effective composite that not only meets stringent economic considerations but also exhibits improved material properties. Within the realm of hybrid metal matrix composites, the well-regarded Al6061 takes on the role of the matrix material, while the synergistic inclusion of fly ash and SiC serves as reinforcing constituents. Three specimens with compostion 90% Al6061 + 5% SiC +5% Fly ash, 90% Al6061 + 10% SiC +6% Fly ash and 90% Al6061 + 15% SiC +7% Fly ash were fabricated. To unravel the intricacies of the fabricated Al6061 metal matrix composite, comprehensive tests are employed. These tests, including the Pin-on Disc test, Scratch test, Rockwell Hardness test, and Charpy Impact test, collectively work to unveil the nuanced tribological and mechanical behaviors encapsulated within this innovative alloy. The results indicated significant improvement in wear resistance in specimen comprising 78% Al6061 + 15% SiC +7% Fly Ash and volumetric loss found to have 0.96 g. Superior hardness characteristics and enhanced abrasion resistance found in 78% Al6061 + 15% SiC +7% Fly Ash than other two specimens. The highest impact strength exhibited in 90% Al 6,061 + 5% SiC +5% Fly ash specimen.