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Maintaining a stable temperature within a battery is essential for optimizing the performance of battery thermal management systems. Phase change materials (PCMs) have demonstrated potential in achieving this stability. This study investigates the use of single-walled carbon nanotubes (SWCNTs) dispersed in three PCMs with varying fusion temperatures to regulate the temperature of a lithium-ion battery (LIB) during discharge, a common scenario in electric vehicles. A Computational Fluid Dynamics (CFD) approach was utilized to simulate the liquid-solid transition of the PCMs, incorporating buoyancy forces in the liquid phase surrounding the LIB. The study examined the effects of different C-rates (1, 2, and 3), SWCNT volume fractions (0, 2, and 4 %), and three types of PCMs (RT27, RT35, and RT58) across multiple simulation scenarios to evaluate their impacts on LIB temperature and PCM melting fraction. Results indicate that nano-enhanced PCMs, which exhibit superior convection effects in the liquid phase, significantly enhance battery cooling performance. Specifically, at a C-rate of 1, using a 4 % volume fraction of nanoparticles in the PCM reduces the battery temperature by an average of 4.138 K compared to cases without nanoparticles. Additionally, while nanoparticles are generally reported to have a minor effect on cooling and melting processes, this study reveals that considering the beneficial effects of SWCNTs and the physical properties of the selected PCMs, the cooling performance of LIBs improves by 4.69 percentage points for the scenario with a C-rate of 3, RT58, and ɸ = 0.02. In this particular case, the melting process is more pronounced in the top half of the battery, where the increased velocity magnitude of the melted region contributes to enhanced battery cooling.

In this research, aligned with global policies aimed at reducing CO2 emissions from traditional power plants, we developed a holistic energy system utilizing solar, wind, and ocean thermal energy sources, tailored to regions optimal for ocean thermal energy conversion (OTEC). The selected site, characterized by favorable wind and solar conditions close to areas with high OTEC potential, is designed to meet the electricity needs of a coastal community. The system's core components include an Organic Rankine Cycle, turbines, thermoelectric elements, pumps, a heat exchanger, a wind turbine, and a solar collector. A detailed system analysis and thermodynamic evaluation based on thermodynamic principles were carried out using the Engineering Equation Solver (EES) software. Key factors such as wind speed, solar radiation, and collector area were critical in determining system performance. To enhance the system's effectiveness, we conducted a comprehensive comparison of optimization algorithms, incorporating the Non-dominated Sorting Genetic Algorithm-II (NSGA-II) and utilizing a Pareto front for value optimization. This approach significantly outperformed other algorithms such as Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and Simulated Annealing (SA) in terms of system efficiency and cost-effectiveness. The developed system achieved an exergy efficiency of 14.46 % and a cost rate of $74.98 per hour, demonstrating its suitability for its intended functions. Moreover, exergoenvironmental evaluation was conducted for the proposed plant. The findings revealed that key component HEX has a high exergoenvironmental factor due to their use of hot water, which has zero unit exergoenvironmental impact. Additionally, pumps demonstrated a zero exergoenvironmental impact factor, indicating negligible component-related environmental impacts. Sensitivity analysis further evaluated critical performance parameters, revealing that increases in solar irradiation lead to decreased total system cost rates, while higher turbine temperatures resulted in a remarkable 14.08 % reduction in the system's cost rate. These results underscore the economic viability of operating the system at higher temperatures and strengthen the argument for its adoption from a financial perspective.

The initial temperature has a considerable effect on aluminum polycrystals' physical stability and mechanical performance, with the possibility to optimize their mechanical properties for practical applications. Thus, using a molecular dynamics technique, the effect of temperature on the mechanical properties of aluminum polycrystals is studied. Stress-strain curves, ultimate strength, and Young's modulus were all measured at temperatures of 300, 350, 400, and 450 K. The findings from MD simulations show that the initial temperature significantly affects the physical stability and mechanical performance of designed aluminum polycrystals. The aluminum polycrystal experiences a numerical increase in ultimate strength and Young's modulus from 6640 to 74.072 to 7.055 and 79.226 GPa, respectively, when subjected to the optimal initial conditions of 350 K. With further increasing temperature to 450 K, ultimate strength and Young's modulus decrease to 6.461 and 74.413 GPa, respectively. The observed decrease in ultimate strength and Young's modulus of the aluminum polycrystal as the temperature increased from the optimal condition of 350 K–450 K can be attributed to the weakening of interatomic attraction forces at higher temperatures. This reduction in interatomic bonding strength resulted in decreased material stiffness and resistance to deformation, leading to lower ultimate strength and Young's modulus values. This study's novelty lies in its comprehensive assessment of the initial temperature's effects on the mechanical performance of aluminum polycrystals, providing valuable insights for practical applications and advancing beyond previous efforts in the literature.

Abstract Drinking water is a crucial need for human survival and solar stills (SSs) have emerged as a cost‐effective solution to meet this need from an economic point of view. In this work, the working of various SSs, their productivity factors, and various devices that can be integrated to improve their efficiency have been studied. The conversion of saline water into freshwater water using SSs has the potential to address the issue of drinking water. This study highlights the importance of SSs as a viable and sustainable solution for drinking water access. On the basis of various parameters correlating to the performance of the SSs, energy, exergy, economics, exergoeconomics, exergoenvironment, and enviroeconomics analysis has been analyzed in this study. To improve the performance and sustainability of SSs, various combinations were studied. These combinations include SSs with different nanoparticle coatings, phase‐change materials, photovoltaic modules, external condensers, wick materials, and reflectors. It is concluded that a comprehensive framework that integrates thermodynamic, economic, and environmental criteria can guide the development of more efficient and sustainable SS technologies.

The main uses of bullets are as projectiles in firearms for military, law enforcement, and civilian purposes. However, bullets have significant industrial applications beyond their role in weaponry, such as precision drilling, cutting, and shaping of hard materials. Steel bullets have a very resistant structure and will not be damaged if exposed to corrosion. Other applications that are resistant to strike and projectiles, such as the automotive and aerospace industries, are based on fibers or fabrics with high toughness and tensile strength, such as Kevlar and p -aramid fibers, which are impregnated with some thermoplastic or thermoset polymers. Therefore, in the upcoming research, the impact of external force (EF) with various values (0.1, 0.2, 0.3, 0.4, and 0.5 V/Å) on the strength of Kevlar nanofibers reinforced with silicon dioxide (SiO2) nanoparticles and ethylene glycol (EG) has been investigated using LAMMPS software. EG and SiO2 nanoparticles with 10 and 2 vol% were added to Kevlar fabrics, creating a shear thickening fluid (STF) nanocomposite. The energy parameters of the interaction between the particles, collision velocity, and the center of mass have been calculated. The findings of the research indicate an increase in the interaction energy from 111271.85 to 154351.15 kcal/mol, an increase in the collision velocity from 0.7046 to 1.5812 Å/fs and an increase in the center of mass from 0.62671 to 1.1670 Å due to the EF applied from 0.2 to 0.4 (kcal/mol)/Å. These results show EF should be optimized in actual cases for the collision process to occur effectively.

Nano-pump is a breakthrough that allows a tiny pump to transfer mass inside the atomic channels. These nanostructures can be used in various applications, such as drug delivery systems in clinical cases. Carbon nanotube (CNT) performance as a nano-pump sample was introduced here. For this purpose, Molecular Dynamics (MD) approach, and external heat flux/electric field effect on nano-pump performance were reported. Hence, various physical parameters, such as nano-pumping time, potential/kinetic energy, stress and entropy were reported to describe the nano-pumping performance of CNT samples. Technically, nano-pumping performance was detected by fullerene (C20) molecule displacement inside the NT. The MD outputs indicated by the heat flux implemented inside CNT, nano-pumping process effectively occur. The results show that by increasing the heat flux amplitude ratio from 0.1 to 0.5 W/m2, the displacement time of C20 molecule decreased from 7.49 to 6.96 ps. By amplitude enlarging, the kinetic energy of defined sample converged to 5.70014 eV. This procedure caused more atomic collisions inside the NT, and the nano-pumping process occurred in a smaller time. Furthermore, the electric field caused the nano-pumping process to be delayed in modeled systems. Numerically, by increasing the electric field, the nano-pumping process occurred after 7.85 ps. Increasing the electric field decreased the mechanical wave produced via Cu tip oscillation. This evolution caused the atomic force, and stress on the target particle converged to a lesser value, and the lattice stress value of modeled sample reached 2.12662 × 106 bar.

The purpose of this study is to examine the effect of different temperatures and sintering times on the microstructure, density, hardness, bending strength, coefficient of friction (COF), fracture toughness, and abrasion rate of Cf/Si3N4 fabricated via the spark plasma sintering (SPS) technique. For this target, the α phase of Si3N4 powder was prepared alongside sintering aids and carbon fiber. Next, five samples were sintered via SPS method at temperatures 1750 °C, 1800 °C, and 1850 °C, under the pressure of 70 MPa, and times of 10, 15, and 20 min. The obtained data illustrated that with an elevation of the sintering temperature from 1750 °C to 1850 °C, the density of the sintered body increased from 91.11 % to 93.03 %, and the hardness rose from 536 to 916 Vickers. Furthermore, upon prolonging the holding time from 10 min to 20 min, the density was enhanced from 93.03 % to 96.53 %, and hardness improved from 916 to 1433 Vickers. The results showed that with an elevation of temperature and time of sintering, the abrasion rate dropped from 14.4 × 10-7 to 4.4 × 10-7 g/N.m due to reducing the porosity of the sample. Finally, with a temperature rise from 1750 °C to 1850 °C, the bending strength of the samples decreased.

Abstract This study reports light energy harvesting characteristics of bismuth ferrite (BiFeO3) and BiFO3 doped with rare-earth metals such as neodymium (Nd), praseodymium (Pr), and gadolinium (Gd) dye solutions that were prepared by using the co-precipitation method. The structural, morphological, and optical properties of synthesized materials were studied, confirming that 5–50 nm sized synthesized particles have a well-developed and non-uniform grain size due to their amorphous nature. Moreover, the peaks of photoelectron emission for bare and doped BiFeO3 were observed in the visible region at around 490 nm, while the emission intensity of bare BiFeO3 was noticed to be lower than that of doped materials. Photoanodes were prepared with the paste of the synthesized sample and then assembled to make a solar cell. The natural and synthetic dye solutions of Mentha, Actinidia deliciosa, and green malachite, respectively, were prepared in which the photoanodes were immersed to analyze the photoconversion efficiency of the assembled dye-synthesized solar cells. The power conversion efficiency of fabricated DSSCs, which was confirmed from the I–V curve, is in the range from 0.84 to 2.15%. This study confirms that mint (Mentha) dye and Nd-doped BiFeO3 materials were found to be the most efficient sensitizer and photoanode materials among all the sensitizers and photoanodes tested.

Abstract Unmanned Aerial Vehicles (UAVs) and their allies have dramatically increased aerospace's energy needs. To meet this need, hybrid power systems and extensive power utilization evaluations must be developed. This research focuses on energy and exergy‐based studies of hybrid wind power systems for fixed‐wing UAVs, which depend on wind turbines and piezoelectric patches. The proposed hybrid wind turbine is planned to be located at the fixed‐wing UAVs' rear position. The wind turbine was initially conceived and built using analytical methods and CAD tools based on power input. The wind turbine's CFD has produced the desired aerodynamic pressures and temperatures, torque, and power. Wind turbine exergy efficiencies have been determined using standard and specialized methods. Wind turbine blades are also patched with PVEH patches to generate hybrid electricity from renewable sources. CFRP‐UD‐Prepreg, CFRP‐Woven‐Prepreg, GFRP‐FR‐4‐Fabric, GFRP‐S‐UD, GFRP‐E‐Fabric, and KFRP‐49‐UD are the lightweight materials used in this work. PVEH patches, along with wind turbines, have been studied for energy and exergy. Modern engineering methods have shown that the proposed hybrid system is better suited to meet high power requirements. Based on this system, the wind turbine system is 0.39226 and the PVEH patches are 0.28131. Finally, aeroacoustic, vibrational, and structural studies are computationally analyzed.

Abstract Solar irradiation is a clean form of energy, and absorption cooling systems powered by solar energy allow for significant energy savings. In the future, the demand for renewable energy may be the most effective way to serve clean energy, especially in Iraq, which has an excellent geographical location. In this research work, the performances of solar collector with and without of preheater have been evaluated. When compared to flat plate collectors at temperatures above 80°C, glass evacuated tube solar collectors provide the combined effects of a highly selective surface coating and vacuum insulation of the absorber element, resulting in a high heat extraction efficiency. Firstly, the Evacuated Vacuum Tube Solar Collector (EVTSC) was tested through experimentation. Secondly, Computational Fluid Dynamics (CFD) approach has been involved in this EVTSC system and thereby the conductive, convective and radiation based heat transfers are computed. Additionally, all possible with inclusive preheater cases are computationally investigated, thereafter the comprehensive report is prepared though validated computational procedures. Finally, the maximum efficiency is observed to be 53% without using a preheater and 61.8% with the usage of the preheater. The increase in efficiency using the preheater is found to be 16.6%.

Abstract Graphene, due to its exceptional optoelectronic characteristics, high charge carrier mobility, wide absorption band, strong light‐matter interactions, and its adjustable nature, has attracted a lot of interest. In light of this, an attempt was made to successfully deposit graphene on a silicon substrate. This results in the formation of a Schottky junction, which could extend the operation window of the graphene/silicon hybrid device to the near‐infrared (NIR) region. Furthermore, since photodetectors built with Van der Waal heterostructures successfully extend the lifespan of dynamic charge carriers with improved the transportation range and speed of charge separation for effective photodetection, the technical development of optoelectronic devices has been greatly accelerated. Recent developments in graphene‐silicon junction‐based devices, their photodetection effectiveness, and active factors that can be used in a variety of applications are outlined, including optical synaptic systems, optical spectrometers, plasmonic devices, optical waveguides, and ultrafast photodetectors. Moreover, the shortcomings of the present optoelectronic devices are also concisely reviewed, along with the viable solutions offered by this new device and its application in next‐generation devices.

Wear-resistant amorphous coatings Fe49.7Cr18Mn1.9 Mo7.4W1.6B15.2C3.8Si2.4 of about 300 μm thickness were deposited on mild steel substrate using a high-velocity oxygen fuel (HVOF) thermal spray method. The median Vickers hardness of the as-sprayed coating is 751.9 HV300 g, which further increases by 127% and by 112% when the coating is vacuum heat treated at 650 °C and 800 °C, respectively. The longer the amorphous phase is, the higher the Vickers hardness is. The relatively low porosity indicates excellent wear resistance of these amorphous coating, which were measured using a pin-on-disc method. The wear mechanism of the current Fe-based amorphous coating varies from oxidative wear to delamination wear when the sliding speed changes from low (0.4 cm/s) to high (4.0 cm/s). It is believed that the upsurge in hardness and the wear resistance of the applied coating is due to the optimized selection of the heat treatment process (i.e., at 650 °C), which has a significant impact on the microstructure, as well as the low porosity, with better coating adherence and fewer cracks. Under dry sliding wear circumstances, the coating demonstrated good wear resistance, with wear rates of (2.81–16.30) x 10−6 mm3/N m. Due to the properties, low porosity, and high hardness especially in case vacuum heat treatment 650 °C, these coatings produced by (HVOF) exhibit a high ability to resist better friction and wear performance that indicates to ability application it in facilities steel.

This paper deals with the Techno-Economic Analysis of dual ejectors –flash tank absorption cooling cycle assisted by solar energy. In this study, the solar system is simulated using the TRNSYS software and a one-dimensional ejector is modeled in EES (Engineering Equation Solver) using NH3/H2O as working fluids. A cooling capacity of 5 kW is considered and a parametric optimization is carried out to select the optimum size of the thermal solar system. The design of the absorption cooling cycle under the Malaysia climate conditions was 5 kW (about 1.5 refrigeration ton) with a solar thermal collector (evacuated tube solar collector of 8.5 m2 sloped at 14° and 0.35 m3 tank size with 0.1 kg s−1 for fluid flow rate). The solar fraction varied between 53.6% in March and 68.6% in February. The payback period and profit gain for the dual ejector cycle, flash –tank with ejector and basic cycle with only ejector are 11 yr, 3192 $; 13.5yr, 1647$; and 16 yr, 874$ respectively. The results also show that the combined dual ejectors-flash tank cycle (Cycle 3) was up to 27% less than of the absorption combined ejector system (Cycle -1), and 10% cheaper than the combined ejector –flash tank absorption system (Cycle -2). Therefore, the economic analysis showed that the absorption system with dual ejectors (Cycle -3) was the preferred option.

Lightweight materials are being employed in aeronautical and automobile industries for high strength, lower weight, and energy consumption. Attention is needed to control pollution through the usage of harmful synthetic composites globally. In this work, coconut shell nanofillers are reinforced in the development of various palm fiber (leaf stalk, leaf sheath, leaf-spine, and fruit) composites using the hand layup technique. Mechanical and morphological effects of the addition of nano-coconut-shell-powder to the composites are addressed. The palm fibers are sandwiched within the glass fiber to improve the strength of composites. The addition of coconut shell nanoparticles in the composites improves the tensile, flexural, impact, hardness, and water absorption characteristics. SEM image observations on the composite indicate the buildup of nanomodified matrix residues around the fiber bundle. The adhesive property of the composite is confirmed by Fourier transform infrared spectroscopy examination, which reveals the presence of one additional alcohol/phenol OH stretch, one less alkyl CH stretch, and aromatic CH bending functional groups. The inclusion of palm fibers during the fabrication of composites facilitated the pushing of curves to higher temperatures with considerable degradation temperatures, thereby increasing thermal stability and making them suitable for thermal applications. Development of the eco-composite changes environmental impact factors aiming sustainability.

The fracture and crack growth of materials can be practically and conveniently predicted through numerical analysis and linear elastics fracture mechanics. On this basis, the current study aims to present experimental work supported by a numerical technique for mimicking the crack propagation by Version 5.6 of COMSOL Multiphysics (version 5.6), used for the simulation of the coating made from Fe-based amorphous material with a thickness of 300 µm. The paper shows the effects of mixed-mode loading on cohesive zone parameters attained from load-crack mouth opening displacement (CMOD) curves. The microstructure dominates the fracture, which in mode I is altered from all-transgranular cleavage to nearly all-intergranular structure in mode II. Two common criteria for failure are linked to the mixed-mode results: Maximum energy release rate criterion (Maximum G) and maximum tensile stress criterion (Maximum S). However, distinguishing between the two criteria is made impossible by the large scatter in the data. The stress intensity factor is the basis for the. The stress intensity factor is the leading parameter facilitated by the singular element and should be estimated with accuracy. With the aim of comparing each criterion and illustrating the numerical schemes’ robustness, a number of examples are presented. It can be concluded that the Maximum G and Maximum S were successful and accurate in predicting the propagation of the Fe-based amorphous material prepared on mild steel.

The conceptual design, component selection, and deployment experiments of an unmanned amphibious system (US) with a unique Becker in vertical stabilizer based on hydrodynamic research are included in this work. The use of USs is currently expanding significantly, and they are used for fish detection, oceanographic mapping, mining detection, monitoring marine life, and navy purposes. With a maximum forward speed of 30 m/s, the US’s hull is largely built with criteria for identifying and researching marine species. The significant lifetime decline of ocean species drives the deployment of unmanned vehicles for species monitoring from the water’s surface to 300 m below the surface. In addition, the medical team can help the species with health problems using this planned US because they have been identified. The conceptual design and estimated analytical equations encompass the fuselage, Becker rudder, propeller, and other sub-components. The locations of sensors, primarily used to locate mobile marine life, are also considered. A Becker rudder has been imposed to make sharp turns when the US is submerged in water. An advanced hydro propeller produces the propulsion with a 20 cm base diameter. Additionally, a piezoelectric patching-based energy extracting approach is used to the hydro-outside propeller’s surface. As a result, the electrical power generation for different lightweight materials is computed for the performance of US manoeuvrings. With the help of CATIA modelling of the intended USs and ANSYS Fluent hydrodynamic simulations, appropriate high-speed configurations are selected. Various stages of its mission profile, including the US in steady-level flight, the US in climb, and the US over the ocean surface, are subjected to computational simulations. Using an advanced computational technique and previously established experimental correlations, the reliability of these various computational solutions is examined and kept at an appropriate level. This US is highly suggested for marine-based real-time applications due to its acceptable output.

Recent large-scale operations, including frequent maritime transportation and unauthorised as well as unlawful collisions of drainage wastes, have polluted the ocean’s ecology. Due to the ocean’s unsuitable ecology, the entire globe may experience drastic aberrant conditions, which will force illness onto all living things. Therefore, an advanced system is very necessary to remove the undesired waste from the ocean’s surface and interior. Through the use of progressive unmanned amphibious vehicles (UAV), this study provides a dynamic operational mode-based solution to damage removal. In order to successfully handle the heavy payloads of ravage collections when the UAV reveals centre of gravity concerns, a highly manoeuvrable-based design inspired by nature has been imposed. The ideal creatures to serve as the inspiration for this piece are tropical birds, which have a long tail for navigating tricky situations. The design initialization was carried out by focusing on the outer body of tropical birds. Following this, special calculations were conducted and the full design parameters of the UAV were established. This study proposes a unique mathematical formulation for the development of primary and secondary design parameters of an UAV. The proposed mission profile of this application is computationally tested with the aid of sophisticated computational methodologies after the modelling of this UAV. The computational methods that are required are one-way coupling-based hydro-structural interaction assessments and computational hydrodynamic analyses. Computing is used to determine the aerodynamic and hydrodynamic forces over the UAV, the lightweight materials to withstand high fluid dynamic loads, and the buoyancy forces to complete the UAV components. These computational methods have been used to produce a flexible and fine-tuned UAV design for targeted real-time applications.

In recent years, the use of unmanned aerial vehicles (UAVs) has increased significantly. Asymmetrical factors, or frictional studies on the disc brake of UAVs, are one of the safety considerations taken into consideration during the design process because UAVs and their components have been built with the best safety in mind. This study focuses on choosing the optimal material for a UAV’s disc brake by using transient structural and thermal models. In order to compare the asymmetry-based frictional force produced by the two ways; the processes used in the transient simulation are validated using pin-on-disc (POD) testing. The foundation for this validation investigation is a metal matrix composite made of an aluminum alloy, and the basis tool is an ASTM G99-based computational test specimen. Steel-EN24 and carbon ceramic matrix composites testing are expanded using the same POD tests. A range of 3 percent to 8 percent error rates is found. As a result, the calculation techniques are applied to the UAV’s disc brake after they have proven to be trustworthy. This fixed-wing UAV’s extensions have a 5 kg payload capacity. The weight, avionics components, tire dimensions, and disc brake dimensions of the other UAV design parts are calculated using analytical formulas. The final designs are made using CATIA as a result. The grid convergence experiment is organized using a traditional finite element analysis tool. Finally, at its maximum rotational speed, a UAV’s disc brake is put through asymmetrical friction testing based on structural and thermal consequences. The correct materials for critical applications, such as carbon fiber-woven-wet-based reinforced polymer and Kevlar unidirectional-49-based reinforced polymer composites for changing rotating speeds, have now been made possible by fixed-wing UAVs.

The consequence of magnetohydrodynamics (MHD) flow on entropy generation analysis and thermal radiation for carbon nanotubes via a stretched surface through a magnetic field has been discovered. The governing partial differential equations are altered into ordinary differential equations with the aid of the similarity variable. Here, water is considered the base fluid with two types of carbon nanotubes, such as single-wall carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs). This domain is used in the energy equation, and then it is solved analytically and transferred in terms of hypergeometric function. The existence and nonexistence of solutions for stretching are investigated. Some of the primary findings discussed in this article show that the presence of carbon nanotubes, magnetic field, and Eckert number develop heat transfer in nanofluids and heat sources and that Eckert number reduces entropy formation. Different regulating parameters, such as Casson fluid, mass transpiration, thermal radiation, solid volume fractions, magnetic constraint, and heat source/sink constraint, can be used to analyze the results of velocity and temperature profiles. The novelty of the current study on the influence of magnetic field entropy analysis on CNTs flow with radiation, is that elastic deformation is the subject of this research, and this has not previously been examined. Higher values of heat sources and thermal radiation enhance the heat transfer rate. The study reveals that thermal radiation, Casson fluid; mass transpiration, Darcy number, and Prandtl number increase, and that decrease in the buoyancy ratio, magnetic parameter, and volume fraction decrease the values of the buoyancy ratio, and also control the transfer of heat.

In this study, Fe2O3 powder was synthesized using the co-precipitation method from scrap iron, which was then treated with varying concentrations of copper. Afterwards, the modified Fe2O3 was reinforced in the PVC matrix by using the solution-casting method to synthesize PVC composite films, which were subjected to a UV-visible spectrophotometer, a Fourier transform infrared spectrophotometer, an X-ray diffractometer, and a thermal gravimetric analyzer to evaluate the optical, chemical, structural, and thermal properties. FTIR analysis reveals the formation of the composite through vibrational bands pertaining to both components present, whereas no significant changes in the XRD patterns of PVC were observed after the doping of modified iron oxide, which reveals the compatibility of fillers with the PVC matrix. The optical properties of the copper-doped iron oxide-PVC composites, including absorbance, refractive index, urbach energy, and optical as well as electrical conductivity are measured, and show an increase in optical activity when compared to the pure PVC compound. Moreover, the increased thermal stability of the synthesized composite was also observed and compared with conventional compounds, which, in accordance with all the other mentioned properties, makes the copper-dopped iron oxide-PVC composite an effective material for electronic, photonic, and optical device applications.

A high-velocity oxygen fuel (HVOF) system was employed to prepare a Fe49.7Cr18Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 amorphous coating on mild steel. The electrochemical behavior of the resultant coatings, namely as-sprayed coating and vacuum heat-treated coating (at 650 °C and 800 °C), were investigated in a 3.5% NaCl solution at variable temperatures using scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, optical microscopy (OM), and XRD diffraction. Moreover, COMSOL Multiphysics version 5.5 software were employed for predicting the galvanic corrosion of amorphous material immersed in an aqueous NaCl solution, using the software finite element kit. The experiments demonstrated that the coatings’ pitting resistance was significantly affected by temperature. The results also showed that temperature affected the pitting corrosion rate and changed the shape of the pits. However, the changes were not as extreme as those observed in stainless steel. Furthermore, there was no significant difference between the as-sprayed coating and the vacuum-heat-treated coating at 650 °C. At low NaCl concentrations at and temperatures below the critical pitting temperature, the resulting pits were significantly small with a hemisphere-like. By contrast, at a higher NaCl concentration at 70 °C, particularly in the case of heating at 650 °C, the pits appearing on the Fe-based amorphous coating were vast and sometimes featured a lacy cover.