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The transportation industry is one of the greatest contributors to a growing carbon footprint. As the world increasingly prioritizes a greener and cleaner future, the transition from ICEs to EVS offers significant benefits as EVs are zero-emission vehicles. However, considering the production and disposal stages of EVs, they cannot be considered entirely emission-free. But in comparison to ICEs, they still have a much smaller carbon footprint. Moreover, studying EV technology is essential to bringing this to the lowest possible extent. However, these advancements come with challenges. In this review article, we have taken an in-depth look into the various challenges, namely the economic challenges, technological challenges, and environmental challenges, faced by EV technology today and the various solutions proposed by researchers, their limitations, and future potential in EV technology advancement. Within this context, we discuss the influence of governmental policies, accessibility and affordability of EVs to the masses, natural and man-made disasters, economic instability, technological limitations posed by the vehicle technology, and limitations posed by battery technology with batteries being the central element for EVs, limitations associated with the existing infrastructure and its ability to support widescale use of EVs, and environmental factors like carbon footprint, among other factors, on EVs technology and the opportunities this technology can make use of in the future. This paper discusses these concerns in detail and gives extensive insight into the challenges, solutions, and future trends pertaining to economic impacts, vehicle technology, battery technology, power grids and charging infrastructure, and environmental impact, of EVs and EV technology.

Synthetic organic dyes and herbicide pollutants pose a significant threat to water quality due to their high solubility in water and widespread industrial discharge. In water conservation developments, the Metal-Organic Frameworks (MOFs) are considered confident and substantial for the exclusion of toxic organic dyes, due to their multi-potential assets of cost-effective, high pore volume, high thermal stability, easy adaptation to toxic dye molecules, and most of them are stable in water, etc. Hence, the green synthetic methodology was employed for the combination of Cu3(BTC)2 MOF, which is draped with carboxylate functionality ligands, as an adsorbent to remove the hazardous dyes of Methyl Orange (MO), Acid Yellow (AY), and toxic herbicide of Atrazine (ATZ) from contaminated wastewater. As-reported Cu3(BTC)2 was evidently characterized by XRD, FTIR, TGA, XPS, SEM, and EDAX analysis. The equilibrium adsorption capacity (Qe) value of as-reported Cu3(BTC)2 for AY, MO, and ATZ was better in comparison with the formerly reported adsorbent. The high adsorption capacity of Cu3(BTC)2 for AY (777 mg/g), MO (903 mg/g), and ATZ (484 mg/g) is principally explained by π-π and electrostatic interaction. As a result, Cu3(BTC)2 is reported and proposed as a suitable adsorbent for the abolition of toxic dyes and herbicides from contaminated water.

The chemical absorption biological reduction process gained profound attention in NOx removal. Treatments for NOx are done popularly using NH3 in selective catalytic reduction (SCR), and deNOx is greatly influenced by catalyst. In recent years, zeolites have been widely explored in ammonia-selective catalytic reduction (NH3-SCR) under low-temperature windows. Different methods were employed to juxtapose the performances of zeolite catalysts with denitrification and NH3-SCR. In this NH3-SCR reaction, the zeolite catalyst’s sulfur and water poisoning effects were also investigated. The negatives of the low-temperature NH3-SCR reactions were demonstrated by using different methods. Ideally, this audit will set upon essential comprehension of the SCR response on zeolite catalysts and clear the way for future exploration to accomplish reasonable applications. The current review provides a new strategy to enhance the removal of NOx and reveals the fundamental effects of different types of sustainable catalysts for the environment. Further, the perspective of the economic aspects of each catalyst is also examined.

This research discusses the behavior of ultra-high-performance concrete (UHPC) specimens made with dumped waste iron ore tailing (IOT) as a fine aggregate in the mix by 30% and 40% in volume fraction along with mono and hybrid fiber incorporation. Basalt fibers of 1%, 2%, and 3%, polypropylene fibers of 0.18%, 0.20%, and 0.22%, and glass fibers of 1%, 1.5%, and 2% of volume fractions were the non-metallic fibers used. Steel fibers as a metallic factor were kept 1% constant throughout the study. The water-to-binder ratio was maintained between 0.15 and 0.17 after sufficient trials. A high-range water reducer was utilized to improve the flowability of the mix. The experimental investigations confirmed that the SG2 mix with 1% steel and 1.5% glass fiber, and 30% IOT, exhibited improved tensile and impact strength compared to standard conventional concrete. This combination exposed an impact energy of 4.05 × 105 kJ for the first crack and 2.7 × 106 kJ for collapse. The energy taken by the specimen between the first crack and the collapse was about 2.3 × 106 kJ. The microstructure was analyzed using Scanning Electron Microscopy. The non–metallic fibers with dominant mechanical properties were thermogravimetrically analyzed.

Many research works have already been made and are still in progress on metallic fibres, as their incorporation reduces the brittleness of the concrete and improves its resistance to the impact and crack propagation. But the use of such non-metallic fibres may induce corrosion which is a major problem to be addressed from the durability aspect. To overcome this problem, in the present research work, a non-metallic hybrid fibre combination was investigated with synthetic fibres like polypropylene and abaca fibres. Also, rather than using conventional cementitious materials such as silica fume, fly ash, and ground granulated blast furnace slag, a new generation of ultra-fine material namely alccofine was used as a partial replacement for the cement by 15%. Abaca fibre was utilised in a constant addition of 0.5% and blended with polypropylene fibre in a range varying from 0% to 2% with an increment of 0.5%. The fresh properties of self-compacting concrete (SCC) in mono and hybrid fibres combinations were assessed through slump flow, J-ring, and V-funnel tests. Water absorption and sorptivity tests were conducted to ensure the durability of the prepared mix. Further, impact tests were carried out on the prepared cylinder specimens to check the capability of the mix with the non-metallic hybrid combination. The main objective here was to check whether a high-strength durable SCC could be achieved using non-metallic fibres and natural fibres. From the obtained experimental results, it was observed that 15% alccofine as a partial substitute to the cement with the addition of 0.5% of abaca fibre and 2% of polypropylene fibre to SCC performed better than the control SCC.

Powder bed fusion (PBF) applies to various metallic materials used in the metal printing process of building a wide range of complex parts compared to other AM technologies. PBF process has several variants such as DMLS (direct metal laser sintering), EBM (electron beam melting), SHS (selective heat sintering), SLM (selective laser melting), and SLS (selective laser sintering). For PBF to reach its maximum potential, machine learning (ML) algorithms are used with suitable materials to achieve goals cost-effectively. Various applications of neural networks, including ANNs, CNNs, RNNs, and other popular techniques such as KNN, SVM, and GP were reviewed, and future challenges were discussed. Some special-purpose algorithms were listed as follows: GAN, SeDANN, SCNN, K-means, PCA, etc. This review presents the evolution, current status, challenges, and prospects of these technologies in terms of material, features, process parameters, applications, advantages, disadvantages, etc., to explain their significance and provide an in-depth understanding of the same.

In present research, the strength properties, impact resistance, and durability characteristics of high-strength concrete blended with nanosilica (NS) and reinforced with multi-walled carbon nanotubes (MWCNTs) are discussed. The proportion consists of nanosilica added in a constant addition of 1% and MWCNT added in a varied dosage of 0.025%, 0.05%, 0.1%, 0.15%, and 0.2% by weight of the cement. A total of 11 mixes were made including the control mix having no MWCNT. The other 10 mixes were categorized into two classes with one class having steel fibres incorporated as 1% of the total volume of the concrete along with the other ingredients such as 1% NS and different proportions of MWCNT. The other class was made without steel fibres retaining only the NS and different MWCNT proportions. Besides the standard compression and tension tests, to determine the energy absorbing capacity of the mix specimens, impact test was also performed. The strength tests were carried out for 3, 7, and 28-day curing. Also, durability tests were carried out with sorptivity, porosity, and mass loss of the specimens when exposed to aggressive HCL and H2SO4 acid. To validate the experiment results, microstructure studies such as scanning electron microscopy (SEM) were also conducted on the samples. Among all mixes, 28-day compressive strength (CS) of 0.2% MWCNT with 1% NS and 1% steel fibre mix was found to increase by 22% compared to control concrete.

One of the significant issues that shorten the life of components used in high-temperature applications is hot corrosion. The current study compares the performance of welded aerospace-grade 80A fabricated through continuous and pulsed gas tungsten arc welding techniques. Weld coupons are produced using two different filler wires (ERNiCrMo-3 (Mo-3) and ERNiCr-3 (Cr-3)). Welded substrates are subjected to 50 cycles of air oxidation and Na2SO4 + 60%V2O5 molten salt environmental conditions at 900 °C. Corrosion products were analysed through scanning electron microscope/energy dispersive spectroscopy and X-ray diffraction analyses. Thermogravimetric analysis revealed that all welded substrates trailed the parabolic rate of law kinetics. In the molten salt (MS) environment, gas tungsten arc welded (GTAW) Mo-3 substrate showed more weight gain. In contrast, a minor weight gain was observed in the pulsed current gas tungsten arc welded (PCGTAW) Cr-3 substrate. It indicates that accelerated corrosion kinetics was observed in the molten salt environmental condition that showed more weight gain than air oxidation. amongst the weldments, pulsed current gas tungsten witnessed superior corrosion-resistant behaviour. This phenomenon is observed due to grain refinement suppression of heat-affected zones and secondary phases in the weld fusion zone. In addition, the appearance of protective oxides such as Cr2O3, NbO and NiCr2O4 helps arrest the oxidation at the surface and sub-surface layer by providing good resistance against hot corrosion to the welded substrate. Thus, utilizing the PCGTAW technique during the fabrication/refurbishing process helps promote the material's corrosion resistance against a hot corrosion environment.

The thermal properties of polymer fibers namely polyvinyl alcohol fiber (PVA) and polypropylene fiber (PP) have been taken for study to carry out this present work. Simulated pore solution (SPS) is prepared by using the combination of chemicals NaOH, KOH, and Ca(OH)2 with distilled water to study the effect of C-S-H gel formation on fibers. The fibers are dipped in the solution for 35 days. The thermal properties of raw and SPS-dipped fibers are fetched out by performing various tests such as Fourier transform infrared (FTIR) analysis, thermo gravimetric analysis (TGA), differential scanning calorimetry analysis, and scanning electron microscopy (SEM). On analysis, the thermal properties of SPS-dipped fiber have better properties when compared with raw fiber. In FTIR analysis the first broad peak of both raw and SPS-dipped fibers are observed between 3000 cm−1 to 2800 cm−1 indicating that fibers have strong bond. In TGA analysis noted that the residual mass of raw fiber (77.19%) is higher than SPS-dipped fiber (52.33%) due to the formation of C-S-H gel formation. DSC analysis showed both endothermic and exothermic reaction under N2 atmosphere.

This paper discusses the possibility of developing a lightweight self-compacting concrete (SCC) with self-curing capabilities. In this regard, a supplementary cementitious material metakaolin, a presoaked lightweight expanded clay aggregate (LECA), and a chemical agent, superabsorbent polymer (SAP), were incorporated in developing a self-compacting self-curing concrete possessing a target strength of 60 MPa through experimental investigations, and the results are reported. The research includes an analysis of basic material properties of constituent materials including fresh properties of concrete and mechanical properties such as compressive and splitting tensile strength. It was inferred from the experimental results that utilization of self-curing agents in SCC has enhanced the mechanical properties when compared with conventional SCC mix. In particular, a combination of 0.3% SAP and 15% LECA gave the optimum strength values. The optimum usage limit of both the materials is presented in this study, and the results prove that SCC can be used as an alternate resource without disturbing the natural resources.

This paper presents the experimental investigation of the load-resisting characteristics of damaged columns repaired with glass reinforced polymer (GFRP) jacketing. The high-strength columns were made with ground granulated blast furnace slag (GGBS) used at 15%, 25%, and 35% as a partial substitute for cement. Cube specimens of size 100 mm × 100 mm × 100 mm and columns of size 600 mm × 120 mm were cast to perform the study. Considering the practical difficulties in the construction field in obtaining river sand, industrial sand was used for making the specimens eco-friendly. On completion of the prescribed curing period of 28 days, the cube specimens were subjected to a compression test to ensure the grade of the mix design, and the column specimens were subjected to axial loading and were tested in two categories, with and without wrapping of GFRP sheets’ split tensile strength. Compression tests on cubes and columns were done. The nondestructive test was also performed with the ultrasonic pulse velocity (UPV) method to check the dense nature of the concrete before and after wrapping with GFRP. On comparing the results, it was observed that it is possible to obtain a higher strength using industrial sand when supported with suitable admixtures and strengthening processes.

Black cotton soils, which are expansive, are present in abundance in Ethiopia. This type of soil possesses expansion when saturated with water and contraction during hot seasons, due to which it is labelled as “weak soil.” They may remain a threat to the structures if they are constructed over them without precautions. The quality of such soils can be improved by treating them with suitable stabilizers or soil reinforcers. This paper discusses the chances of using the second waste of plastic bottles as a reinforcer to strengthen weak black cotton soils in Ethiopia. Second, plastic bottle waste was added at 1%, 2%, 3%, 5%, 7%, and 9% to the soil, and numerous trials were conducted to ensure the reliability of the results. The effects were analyzed based on the results from the Atterberg limit tests, compaction tests, unconfined compression strength (UCS) tests, and the California bearing ratio test (CBR) for soaked and unsoaked conditions. The results were compared against the natural soil results, and the optimum usage percentage of second waste plastic required to reinforce the soil was reported. The results indicate that among the various properties used, the mix with 2% second waste plastic is effective with numerous trials being conducted to ensure the reliability of the results and decreased values of OMC by 18.5%, increased MDD by 1.9%, increased CBR by 50.9%, and increased UCS by 10.1%. Thus, the research provides a novel technique to recycle plastic waste once again as soil reinforcement, thereby saving the environment from dumped waste.

Micro-electric discharge machining (Micro-EDM) is deployed for machining hard-to-machine materials, such as various grades of titanium alloys, heat-treated alloy steels, composites, tungsten carbides, and so forth. Mild steel is known for its easy machinability. However, conventional machining of mild steel can often lead to the built-up edge formation on the tool. There is a minimal focus on machining ductile materials using nonconventional machining processes. This is due to the rapid work hardening in cold forming conditions. In the present study, the aluminium alloy 6061 and mild steel AISI 304 were taken as a work piece. Input pulse on factors considered as three levels and orthogonal array utilized to optimize the EDM parameters. Numerical results confirm the influence of input parameters in the response. The highest MRR is obtained at Ton = 40 μs and Toff = 4 μs, and the least MRR is acquired at Ton = 20 μs and Toff = 3 μs. The fruit fly algorithm and the cockroach swarm algorithm were used to predict the optimal minimized MRR value. The experimental results show that the cockroach swarm algorithm was performing better than the fruit fly algorithm in the MRR minimization process.

The Vertical Take-off and Landing (VTOL) unmanned aerial vehicles (UAVs) with the tilt-rotor mechanism also known as hybrid UAVs have a lot of challenges in designing and controlling concerning their use in harsh weather for surveillance and access to remote areas. This review paper presents a review of the preliminary design of hybrid aircraft and control systems. The tilt-rotor mechanism and tilt wings of a hybrid UAV are analyzed. The paper provides an outline of technical advances in UAVs in hybrid configuration concerning their constraint analysis, propulsion sizing, and design evaluation. Furthermore, the flight dynamics modeling is described with the control system and dynamics of the hybrid UAV. This paper lists various software for simulations and analysis such as SOLIDWORKS and CATIA for CAD modeling, MATLAB and SIMULINK for mathematical modeling and flight control, and XFLR5 for stability analysis of aerofoils, wings, and planes. In addition, certain control strategies are executed and scrutinized in terms of the theory, the linearity, and the implementation of the model.

Additive manufacturing (AM) has been gaining pace, replacing traditional manufacturing methods. Moreover, artificial intelligence and machine learning implementation has increased for further applications and advancements. This review extensively follows all the research work and the contemporary signs of progress in the directed energy deposition (DED) process. All types of DED systems, feed materials, energy sources, and shielding gases used in this process are also analyzed in detail. Implementing artificial intelligence (AI) in the DED process to make the process less human-dependent and control the complicated aspects has been rigorously reviewed. Various AI techniques like neural networks, gradient boosted decision trees, support vector machines, and Gaussian process techniques can achieve the desired aim. These models implemented in the DED process have been trained for high-precision products and superior quality monitoring.

This paper presents analysis and comparison into mechanical behaviour and microstructural attributes of postweld heat-treated AISI 1020 (0.21%-C) plates joined by the shielded metal arc welding (SMAW) process. The purpose of this work is to heat the welded samples uniformly so that a possible formation of austenite can be obtained, and hence, residual stresses, if any, can be recovered. Four pairs of such steel were taken and welded to form four joints. Welding was followed by heat treatment. The heating temperature and holding time were selected as 1040°C and 60 minutes, respectively. Different cooling media such as sand, water, oil, and air were used to cool the samples. Hence, there were four different samples according to their physical conditions: sand-cooled, water-quenched, oil-quenched, and air-cooled. For analysing mechanical behaviour of all the plates, standard-shaped specimens were prepared out of them. The tensile strength, impact strength, hardness, and the microstructural attributes were analysed in four welded samples after heat treatment. Significant variations in tensile strength and hardness were reported when compared with each other. Oil-cooled sample showed a remarkable enhancement in tensile strength. The sand-cooled sample possessed the highest toughness, whereas water-quenched samples were found to be highly hard. Furthermore, a good combination of strength, hardness, and ductility was reported in oil-cooled sample. Pearlite (coarse and fine) and martensite were the main microstructural findings in the study. A clear vision of ferrite, cementite, and martensite on various heat-treated samples made this study important. All the mechanical properties are in good corroboration with microstructure. A significant refinement into all the mechanical properties was achieved in this work.

Argon arc welding is a frequently used process, to assist various manufacturing processes. The paper highlights the postweld experimental results of similar (EN 10025 Steel-Grade S295) and dissimilar (D36 shipbuilding steel) materials, which possess a wide range of applications in manufacturing industries. In this work, experimental studies are carried out for optimality of gas tungsten arc welding (GTAW) parameters on a butt joint with single and double V 45° groove angles using Taguchi orthogonal L9 array design. The welding is carried out using the back hand technique, and the filler rod is taken as ER303L to obtain finer welded joints. After the weld, residual stresses, microhardness, and geometrical properties of weld are studied at varied zones, that is, weld zone, HAZ, and base metal to examine the weld efficiency with specific predefined weld parameters. Furthermore, tensile tests are carried out for the weldments with optimal predefined weld parameters, and subsequently, the welded specimens with better tensile strength are discussed in the results. Genetic algorithm and mathematical modelling are opted for selecting the final optimal welding parameters. As per the obtained results of residual stresses, hardness, and tensile tests, dissimilar double V groove butt joint is projected to have more effective weld joint.

Automatic image caption generation is an intricate task of describing an image in natural language by gaining insights present in an image. Featuring facial expressions in the conventional image captioning system brings out new prospects to generate pertinent descriptions, revealing the emotional aspects of the image. The proposed work encapsulates the facial emotional features to produce more expressive captions similar to human-annotated ones with the help of Cross Stage Partial Dense Network (CSPDenseNet) and Self-attentive Bidirectional Long Short-Term Memory (BiLSTM) network. The encoding unit captures the facial expressions and dense image features using a Facial Expression Recognition (FER) model and CSPDense neural network, respectively. Further, the word embedding vectors of the ground truth image captions are created and learned using the Word2Vec embedding technique. Then, the extracted image feature vectors and word vectors are fused to form an encoding vector representing the rich image content. The decoding unit employs a self-attention mechanism encompassed with BiLSTM to create more descriptive and relevant captions in natural language. The Flickr11k dataset, a subset of the Flickr30k dataset is used to train, test, and evaluate the present model based on five benchmark image captioning metrics. They are BiLingual Evaluation Understudy (BLEU), Metric for Evaluation of Translation with Explicit Ordering (METEOR), Recall-Oriented Understudy for Gisting Evaluation (ROGUE), Consensus-based Image Description Evaluation (CIDEr), and Semantic Propositional Image Caption Evaluation (SPICE). The experimental analysis indicates that the proposed model enhances the quality of captions with 0.6012(BLEU-1), 0.3992(BLEU-2), 0.2703(BLEU-3), 0.1921(BLEU-4), 0.1932(METEOR), 0.2617(CIDEr), 0.4793(ROUGE-L), and 0.1260(SPICE) scores, respectively, using additive emotional characteristics and behavioral components of the objects present in the image.

One of the most suitable methods for the mass production of complicated shapes is injection molding due to its superior production rate and quality. The key to producing higher quality products in injection molding is proper injection speed, pressure, and mold design. Conventional methods relying on the operator’s expertise and defect detection techniques are ineffective in reducing defects. Hence, there is a need for more close control over these operating parameters using various machine learning techniques. Neural networks have considerable applications in the injection molding process consisting of optimization, prediction, identification, classification, controlling, modeling, and monitoring, particularly in manufacturing. In recent research, many critical issues in applying machine learning and neural network in injection molding in practical have been addressed. Some problems include data division, collection, and preprocessing steps, such as considering the inputs, networks, and outputs, algorithms used, models utilized for testing and training, and performance criteria set during validation and verification. This review briefly explains working on machine learning and artificial neural network and optimizing injection molding in industries.

Phase change materials are the category of materials that release or absorb enough energy during phase change transformation to provide heating or cooling. Divided into two principal classes of organic and inorganic, these materials find a wide range of uses in commercial applications of casting where stable temperature and heat storage are a requirement. In this research work, application of inorganic phase change materials having significantly elevated temperature zone, especially within metal casting processes, has been discussed. Phase change material with high enthalpy of fusion and high melting point can be used for metal casting, but in a limited temperature range (between 200°C and 1300°C). In sand casting, inorganic PCM has the potential to be used as chills to provide directional solidification. Despite having advantages, inorganic PCM comes with major disadvantages, that is, toxicity, corrosivity, supercooling, and low thermal expansion. Few solutions to overcome these problems have been discussed in this research paper. Future research is required to reduce the disadvantage to a low level, so that PCM can be used in application where elevated temperature is achieved.

This paper discusses the permeation characteristics of concrete made by increasing the fineness of the conventional mineral admixtures and using them as a partial substitute for cement. Silica fume and metakaolin ground to ultrafine state and ceramic powder obtained from grinding waste ceramic tiles were used as mineral admixtures. The mixes were designed for a compressive strength of 50 MPa and were prepared for both binary and ternary blended cases. Binary blended specimens were cast, partially replacing cement with unground silica fume, ground silica fume, unground metakaolin, and ground metakaolin separately in different replacement proportions. Ternary blended mixes were prepared using ceramic powder in 4%, 9%, and 14% and with silica fume in a constant level of 1% percentage. All the cast specimens were compared against the control concrete. A deeper comparative analysis was also made by comparing the performance of specimens made with unground mineral admixtures with that of ground mineral admixtures. Various parameters such as resistance against water absorption, percentage of voids, and sorptivity characteristics were studied. It was observed that increasing the fineness helps fill up the pores, thereby improving the resistance to permeation action.

The world is rapidly changing, the resources are getting depleted, and the demand for newer technologies and products is increasing. To keep up with these new advances, highly efficient catalytic routes need to be taken to be sustainable and ensure a drawn-out existence of resources for future generations. Catalysis turns out to be a significantly important field of application when it comes to the era of nanoscience, where all devices and technologies are becoming smaller and smaller in size with improved properties. When deeming the usability of a catalyst, it is of paramount importance to have a good understanding of their properties and their synergistic effect on the other reagents in the reaction. Over the last decade, the field of nanocatalysis has grown rapidly, both in homogeneous and heterogeneous catalysis. Given that nanoparticles have a high surface-to-volume ratio when compared to bulk materials, they are appealing as catalysts. Catalysts accelerate and boost thousands of different chemical reactions on a daily basis, forming the foundation of the multibillion-dollar chemical industry worldwide, a pathway leading to green chemistry, and a novel, yet crucial, environmental protection technology. As a result, in this review, the use of nanocatalysts and the application of their special features in the renewable energy, hydrocarbon processing, and fine chemical synthesis sector was explored. A detailed explanation of the working mechanism of these nanocatalysts, starting from how they are synthesized to the effect of modification of their surface, has been put together. We have tried to collect all the current progresses in these three sectors to the best of our abilities. Furthermore, it is anticipated that this paper would be useful for future researchers and academicians wishing to contribute toward this subject of interest.

Freeze casting, popularly known as ice templating or freeze gelation, is a mechanical method to fabricate scaffolds of desirable properties and materials. Aerospace engineering, the healthcare sector, manufacturing department, and automotive industries are the different fields where freeze casting has been used. Bioinspiration refers to the translation of biological systems into new and innovative creations. Bioinspired materials are extensively used in freeze casting methods such as ceramide, spines of porcupine fish, and collagen. Due to the tunable properties and production of complex structures with ease, biomaterials have found numerous applications in the ice templating method. This review rigorously explains the freeze casting process and the effect of thermal conductivity, stress, and electrostatic repulsion on the porous materials. Also, we have discussed the different biomaterial polymers used in freeze casting along with different methods involved.

This study evaluated the physical-mechanical properties of three-layer particleboard made from sorghum stalk and sugarcane bagasse hybrid reinforced bonded with urea-formaldehyde resin. The production of particleboards using the sorghum and bagasse particles has been established at the ratio of (25 : 50 : 75) sorghum stalk and sugarcane bagasse with urea-formaldehyde as a matrix at different concentrations (50 kg/m3, 60 kg/m3, and 70 kg/m3) and pressing pressure (18 MPa, 20 MPa, and 22 MPa) through hand mixing from 3 to 5 minutes and then hot press within a temperature range of 160°C to 180°C for 4 minutes. The particleboards were produced with their proportions through the Taguchi design of the experiment (L9) approach. The experimental results were analyzed using Taguchi design and ANOVA with a general linear model. The experimental results showed that internal bonding, flexural strength, modulus of elasticity, and moisture content were significantly improved with high resin content and pressing pressure from 18 MPa to 22 MPa. The thickness swelling value also dropped where the resin concentration varies from 50 kg/m3 to 70 kg/m3 and shows better board stability. In contrast, the water absorption increased as resin content was increased. Results from ANOVA provide that SS3B1P3UFR3 (3 : 1 ratio of Sorghum with bagasse, 22 MPa of pressing load, and 70 kg/m3 urea-formaldehyde concentration) is the most optimal combination of variables for the better performance of particleboard.

In harsh working environments where there can be very high temperatures and heavy loads, like in the inside of the combustion chamber of a rocket, industrial gas turbines, space vehicles, and so on, a special class of material will be needed for making the required parts. This special class of materials is called superalloys. There are many types of superalloys based on the major alloying element. But, among these, Ni-superalloys stand out significantly due to their superior mechanical and physical characteristics. Thus, they are widely used in situations where the working conditions are unbearably harsh for ordinary materials. And, due to this, a lot of research have been done on Ni-superalloys for improving them and studying their properties. This extensive research work has led to the development of many generations of Ni-superalloys, with alloys getting better and better with each passing generation. Among all generations, the 5th and 6th generations of Ni-superalloys are the most recently developed ones. With the development of 5th and 6th gen alloys being very recent, there are not many studies conducted on them. With the current bloom in aerospace, energy, and thermonuclear research fields, the need for materials such as Ni-superalloys that can withstand absurdly harsh environments is increasing. That is one of the reasons why reviewing existing studies pertaining to recently developed new generation alloys is very important. It can help us in finding out the future possibilities for research so that we can develop new alloys or improve the existing ones. In this review paper, various aspects of these alloys such as fatigue properties, creep properties, oxidation resistance properties, corrosion resistance properties, element composition of these alloys and their impact on the above factors, use of various manufacturing methods, and the presence of additives have been extensively studied.

Energy storage systems are becoming increasingly important, with a growing focus on renewable energy sources that provide highly fluctuating output. Therefore, sound decisions regarding the energy storage systems to be employed need to be made, especially with a systematic and semantic approach. This paper considers the problem of evaluation and selection of energy storage technologies (ESTs). The objective of the proposed research is to decide the best technology for energy storage under the novel idea of hybrid multicriteria decision-making technique under fuzzy environment, that is, fuzzy AHP with fuzzy VIKOR. Electrochemical storage, electrical storage, magnetic storage, mechanical storage, and chemical storage are considered as five alternative energy storage technologies. Energy density, life cycles, cycle efficiency, investment level, suitability to climatic conditions, and required space are considered as six main evaluation criteria. Under each of the main criteria, a set of subcriteria are also considered. The weights of main criteria and subcriteria are determined using fuzzy AHP. With the help of the weights of each set of subcriteria, the weights of alternatives are determined using fuzzy VIKOR. Further, with the help of the main criteria weights and the weights of alternatives determined with respect to each set of subcriteria, the final normalized weights of alternatives are determined. Based on these weights, energy storage technologies are ranked. In addition, the sensitivity analysis is carried out to analyze the variation in ranking pattern of alternatives. From the research findings of this paper, the results are found to be more practical as the evaluation is carried out on an objective basis.

The swiftly growing global economies remain the root cause of the soaring demand for oil and gas to satisfy their excessive energy demands, thus making the oil and gas sector one of the most important industrial sectors. Though renewable energy technologies are the more sustainable option, technological advances are required to make them more accessible to the common people. Therefore, due to the limitation of renewable energy technologies, oil and gas continue to be a more viable alternative. Extensive research is being conducted on the applications of nanotechnology to make the upstream, midstream, and downstream processes efficient in the oil and gas sector. Nanomaterials make the activities in processing and transportation more economical, efficient, and environment-friendly than their conventional counterparts. In this review, we have highlighted the need for nanomaterials in oil and gas, for example, in crude oil exploration, including drilling and EOR, separation techniques, refining, transportation, and other related activities. Further, this review summarizes novel nanomaterials developed and used in the activities mentioned above, and at the end, we have briefly described the synthesis mechanism of these nanomaterials. Finally, we emphasize the current challenges and future work prospects in this area of study.

The Aluminum metal matrix with particulate reinforcements is the new future of the coming industrial revolution due to the higher strength and availability. Composite reinforcements such as SiC, TiB2, B4C, and others contribute significantly to the increased strength of the Aluminum metal matrix, which can be an optimal choice, also at a lower cost, in some applications where Aluminum is considered or proven to withstand high temperatures. Ultrasonic welding is the process, where, we get the electrical energy, which converts and amplifies into vibration energy for the welding to occur. The challenge we face today is the thickness limitations in ultrasonic welding. The ultrasonic welding of the Aluminum metal sheet with the reinforcements may affect it, as the addition of particulate reinforcements will increase the strength of the Aluminum matrix. Ultrasonic welding can only support a metal sheet with a thickness of up to 2.5 mm in the case of an Aluminum plain sheet. However, if the strength of the Aluminum metal matrix increases, the next step is to achieve ultrasonic welding with the same thickness of Aluminum matrix and reinforced composites that have greater strength than a standard Aluminum sheet. This review will focus on the parameters and the factors which may help decrease the difficulties of Ultrasonic Welding of Aluminum MMC, alongside reviewing the current technologies and research works.

Any metal surface’s usefulness is essential in various applications such as machining and welding and aerospace and aerodynamic applications. There is a great deal of wear in metals, used widely in machines and appliances. The gradual loss of the upper metal layers in all metal parts is inevitable over the machine or component’s lifetime. Artificial intelligence implementations and computational models are being studied to evaluate different metals’ tribological behavior, as technological progress has been made in this field. Different neural networks were used for different metals. They are classified in this paper, together with a description of their benefits and inconveniences and an overview and use of the different types of wear. Artificial intelligence is a relatively new term that uses mechanical engineering. There is still no scientific progress to examine various metal wear cases and compare AI and computational models’ accuracy in wear behavior.

In this review article, research papers related to recent developments in Ni-superalloy technologies have been reviewed in order to provide an insight into recent achievements and the potential for further study, research, and development in this field. In this paper, studies on various aspects of Ni-based superalloys are reviewed, such as production methods, which include widely used casting methods, as well as unconventional alternative procedures, novel techniques, or simulation and prediction of certain alloy casting properties. Reviewing was done by categorising the papers into 4 major categories: manufacturing of Ni-based superalloys, effects of alloying elements, physical and mechanical properties of Ni-based superalloys, and defects in Ni-based superalloys. The process used to make Ni-superalloy parts can have a huge impact on the production process efficiency, the final product’s quality and properties, and the defects formed in it. Investment casting is one of the most common methods for making Ni-superalloy parts. Manufacturing covers studies on various casting methods used to make Ni-based superalloy components, novel techniques and methods developed to improve casting procedures to produce better products, and alternative manufacturing methods like AM and HIP processing. Similar to production process, the role of alloying elements is also very important. Even minor changes in their compositions can cause significant changes in the final product. Simultaneously, these alloying elements appear to be more efficient in the development of new methods to control product quality, suppress defect formation, and improve material properties such as the creep and fatigue. As a result, the effects of various alloying elements used in castings of Ni-based superalloys are thoroughly examined. A material’s properties are its most important components. They assist the industrialist in selecting or developing a material based on the needs of the application/use. With this in mind, many researchers have conducted extensive research on physical and mechanical properties, as well as how to improve them. Fatigue life, stress rupture, creep properties, impact ductility, strain response, stress relaxation behaviour, and so on are some of the most important physical and mechanical properties of Ni-superalloys. This article thoroughly reviews various studies on these properties, how and by what factors they are affected, and how they can be improved. Another important factor to consider when making Ni-superalloy castings is defect formation, which can affect the properties of the final product. Freckle defects, hot tears, porosities, and slivers are some of the major defects that occur in Ni-superalloys during the casting process. This article also reviews in detail about these defects, how they form, and how they affect the final product. These defects were found to have a significant influence on a variety of properties, such as creep, fatigue behaviour, and fracture mechanism. Topics and areas such as reinforcement of Ni-superalloys with the help of CNCs and 3D printing of Ni-superalloys that can provide scope for potential future research are highlighted based on the above-reviewed papers.

Thermal barrier coating plays a vital role in protecting materials’ surfaces from high-temperature environment conditions. This work compares the demeanour of uncoated and air plasma sprayed Cr _3 C _2 –25NiCr and NiCrMoNb coated X8CrNiMoVNb16–13 substrates subjected to air oxidation and molten salt (Na _2 SO _4 + 60%V _2 O _5 ) environment condition at 900 °C for 50 cycles. Coating characteristics have been analyzed through microstructure, thickness, porosity, hardness, and bond strength. SEM, EDS and XRD analysis were used to analyze corrosion’s product at the end of the 50th cycle. Coating microstructures showed a uniform laminar structure that is adherent and denser with a coating thickness of 150 ± 20 μ m and porosity less than 3.5%. The Microhardness of both the coated substrates were higher than that of the bare substrate. Cr _3 C _2 –25NiCr and NiCrMoNb coating bond strength was 38.9 MPa and 42.5 MPa. Thermogravimetric analysis showed the parabolic rate law of oxidation for all the substrates in both environments. In the molten salt environment, all the substrates exhibited higher weight gain compared to the air oxidation environment. In both environmental conditions, the uncoated X8CrNiMoVNb16–13 alloy exhibited higher weight gain than the coated substrates. The formation of Cr _2 O _3 , NiO and spinel oxide NiCr _2 O _4 offers good resistance to corrosion to all the substrates in both the environmental condition. However, the presence of Mo and Nb significantly accelerated the corrosion of the substrate, thereby increasing the weight of the NiCrMoNb substrate. It is observed that Cr _3 C _2 –25NiCr and NiCrMoNb coating over the X8CrNiMoVNb16–13 substrate significantly protected the substrate against the hot corrosion than the bare alloy exposed to similar environmental conditions.

Water is a necessity for all living and non-living organisms on this planet. It is understood that clean water sources are decreasing by the day, and the rapid rise of Industries and technology has led to an increase in the release of toxic effluents that are discharged into the environment. Wastewater released from Industries, agricultural waste, and municipalities must be treated before releasing into the environment as they contain harmful pollutants such as organic dyes, pharmaceuticals wastes, inorganic materials, and heavy metal ions. If not controlled, they can cause serious risks to human beings’ health and contaminate our environment. Membrane filtration is a proven method for the filtration of various harmful chemicals and microbes from water. Carbon nanomaterials are applied in wastewater treatment due to their high surface area, making them efficient adsorbents. Carbon nanomaterials are being developed and utilized in membrane filtration for the treated wastewater before getting discharged with the rise of nanotechnology. This review studies carbon nanomaterials like fullerenes, graphenes, and CNTs incorporated in the membrane filtration to treat wastewater contaminants. We focus on these CNM based membranes and membrane technology, their properties and applications, and how they can enhance the commonly used membrane filtration performance by considering adsorption rate, selectivity, permeability, antimicrobial disinfectant properties, and compatibility with the environment.

Chitosan has become the most known and second abundantly available recyclable, non-hazardous and eco-friendly biopolymer after cellulose with several advantageous biomedical, agriculture, and wastewater treatment applications. As nanotechnology has progressed, researchers have begun incorporating chitosan-based carbon compounds into various compounds, elements, and carbonaceous materials to increase their efficiency and biocompatibility. Chitosan carbon compounds have also been used directly in many applications due to their inherent chelating and antibacterial features and the presence of customizable functional groups. This review widely discusses- the properties and synthesis of chitosan and chitosan composite. It also discusses the modification of chitosan with different compounds, metals, carbonaceous materials, and agriculture residues to allow their use on an industrial scale. Recent advances in the use of chitosan in biomedical, agro-waste management, agriculture, wastewater treatment, and a few other applications (such as food packaging, cosmetics, and the textile and paper sector) are briefly discussed. Furthermore, this analysis reveals that chitosan and its composite materials are potential, low-cost products for environmental clean-up that can be made with basic manufacturing procedures.

The high-temperature corrosion behavior of constant current gas tungsten arc (GTA) and pulsed current gas tungsten arc (PCGTA) welded Hastelloy X with different filler wires (C263 and ERNiCr-3) are studied for 50 cycles at 900 °C. Molten salt I (MS I) (75% Na _2 SO _4 + 25% V _2 O _5 ) and molten salt II (MS II) (75% Na _2 SO _4 + 20% V _2 O _5 + 5% NaCl) were coated on the welded specimens. MS II coated substrate shows the highest weight gain than MS I with a parabolic constant for GTA ERNiCr-3 as 21.440 × 10 ^–6 mg ^2 /(cm ^4 .s). Whereas PCGTA C263 welded sample with MS I, revealed parabolic constant (lowest) of 0.008 × 10 ^–6 mg ^2 / (cm ^4 .s). Based on the results, an increasing pattern of hot corrosion resistance of substrates is arranged as GTA ERNiCr-3

Artificial Intelligence has left no stone unturned, and mechanical engineering is one of its biggest consumers. Such technological advancements in metal melting can help in process simplification, hazard reduction, human involvement reduction & lesser process time. Implementing the AI models in the melting technology will ultimately help various industries, i.e., Foundry, Architecture, Jewelry Industry, etc. This review extensively sheds light on Artificial Intelligence models implemented in metal melting processes or the metal melting aspect, alongside explaining additive manufacturing as a competitor to the current melting processes and its advances in metal melting and AI implementations.

The present work deals with a critical fractographic analysis into low carbon (0.18%-C) steel samples which were used for three different mechanical tests: tensile test; shear test; and toughness test. These mechanical tests were performed in standard sized specimens as recommended by ASTM. In each category of test, there were two different specimens with different physical states according to heat treated conditions. First specimen was in ‘as received’ condition and another was annealed. For annealing, sample was first heated up to austenitic temperature and inserted inside the sand for slow rate of cooling. As these two categories of samples were undergone through destructive tests, the variation in fracture behaviour of the samples was analysed by FESEM, XRD. A significant variation in fractographic images could be observed in different heat-treated samples. Micro-pores, dimples, cleavage facet, peaks, valleys, and cave formation were observed in the samples.

The present work deals with improvement of mechanical properties and refining the microstructure of low carbon steel (0.2%-C) after applying heat treatment techniques. For the purpose, five different samples were taken under study. First sample was kept in ‘as received’ condition and other four samples were undergone into heating process in an Induction furnace. The holding temperature of all the four samples were kept common i.e., 850 °C for a fixed period of 2.5 h. Then, these four samples were cooled into four different cooling media i.e., Air, Water, Oil, and Furnace. All the samples were in the form of rods with 195 mm length and 32 mm diameter. The universal testing machine was used to determine the tensile strength of all the samples. Rockwell hardness tester was used to find the hardness of samples. The microstructural variation was analysed through an optical microscope. All the results were analysed and compared with ‘as received’ sample. The Oil cooled sample showed the highest tensile strength of 585 MPa. The microstructural orientation of oil cooled sample i.e., bainite + fine lamella of ferrite and cementite, provides a good hardness, strength, and toughness to the steel. In addition, XRD and fractography analysis of the samples were also carried out.

This study presents a detailed experimental investigation on the effects incorporating non-metallic fibers in hybrid form in self-compacting concrete (SCC). In this regard SCC was prepared with Alccofine and Metakaolin as partial replacement for cement in 15% and 20% respectively along with the hybrid fibre combinations namely abaca fibres (0.25%, 0.5% & 0.75%), polypropylene fibres (0.5%, 1%, 1.5% & 2%) and glass fibres (0.5%, 1%, 1.5%, & 2%). The fresh properties of SCC with and without hybrid fibre combinations were assessed through the standard tests such as slump flow, J ring and V-funnel tests. The conventional mechanical tests such as compressive strength test, split tensile strength test and flexural strength test were performed at 7 and 28 days. The experimental results reveal that the fresh properties of SCC were highly influenced by alccofine and Metakaolin adopted in this research. Furthermore, that the hybrid combination of abaca with polypropylene and glass fibres improved the mechanical properties of SCC and in particular the mix with 1% glass fibre and 0.25% Abaca fibre had shown better flexural and tensile strength behaviour. Microstructure analyses were also done to confirm the improvement in mechanical properties. The Scanning Electron Microscope images of the mix with 1% glass fibre and 0.25% abaca fibre showed less voids presence and presence of more hydrated components conveying that the usage of hybrid fibres had restricted the propagation of cracks there by reducing the percentage of voids and the use of metakaolin and alcofine helping in forming hydrated components at earlier stage leading to better strength.