As a technique of producing fabric engineering scaffolds, three-dimensional (3D) printing has tremendous possibilities. 3D printing applications are restricted to a wide range of biomaterials in the field of regenerative medicine and tissue engineering. Due to their biocompatibility, bioactiveness, and biodegradability, biopolymers such as collagen, alginate, silk fibroin, chitosan, alginate, cellulose, and starch are used in a variety of fields, including the food, biomedical, regeneration, agriculture, packaging, and pharmaceutical industries. The benefits of producing 3D-printed scaffolds are many, including the capacity to produce complicated geometries, porosity, and multicell coculture and to take growth factors into account. In particular, the additional production of biopolymers offers new options to produce 3D structures and materials with specialised patterns and properties. In the realm of tissue engineering and regenerative medicine (TERM), important progress has been accomplished; now, several state-of-the-art techniques are used to produce porous scaffolds for organ or tissue regeneration to be suited for tissue technology. Natural biopolymeric materials are often better suited for designing and manufacturing healing equipment than temporary implants and tissue regeneration materials owing to its appropriate properties and biocompatibility. The review focuses on the additive manufacturing of biopolymers with significant changes, advancements, trends, and developments in regenerative medicine and tissue engineering with potential applications.

Composite materials with carbon nanotube and graphene attachments have been regarded as promising prospects. Carbon nanocomposites have gained considerable interest in different fields including biomedical applications due to its exceptional structural dimensions and outstanding mechanical, electrical, thermal, optical, and chemical characteristics. The significant advances made in carbon nanocomposite over past years along with the discovery of new nanocomposite processing technologies to improvise the functional impact of nanotube and graphene composites by providing proper methods of synthesis and improving the production of diverse composite based on carbon nanomaterials are discussed. Carbon nanocomposites are applied in various fields such as aviation, batteries, chemical industry, fuel cell, optics, power generation, space, solar hydrogen, sensors, and thermoelectric devices. The recent design, fabrication, characteristics, and applications of carbon nanocomposites such as active carbon, carbon black, graphene, nanodiamonds, and carbon nanotubes are explained in detail in this research. It is found that unlike traditional fiber composites, Van der Waals force interfacial compounds have an important effect on the mechanical performance of carbon nanomaterial-based composites.

Climate change, clean air, renewable energy, nontoxic surroundings, and the opportunity to live in a healthy community are just few of the issues that environmental sustainability addresses. To improve environmental health and quality of life, several researchers have turned their attention to alternative energy sources like ethanol and oxyhydrogen. In latest years, significant progress has been made in the development of ethanol and hydrogen as clean energy sources. A higher octane rating is achieved by mixing ethanol with gasoline rather than using regular gasoline. A novel mix of oxyhydrogen, ethanol, and gasoline is ecologically friendly while simultaneously increasing the performance of gasoline engines. In this study, a nanoparticle‐coated piston on a low heat rejection gasoline engine fuelled by an ethanol‐gasoline mix with oxyhydrogen addition was investigated. It has been evaluated that thermal efficiency improved by up to 25% while fuel consumption can be reduced by up to 28% on a volume basis compared to the baseline engine. Furthermore, the decrease in harmful carbon monoxide reached around 10%, and the reduction in unburned hydrocarbon emissions reached 18%.

The study is to investigate the physical, mechanical, and tribological properties of Al6063 alloy reinforced by Silicon Nitride (Si₃N₄) & compound Copper Nitrate (CuN₂O₆) processed via Powder Metallurgy (PM) Techniques. Incorporation of reinforcement in matrix material ranged from 6 to 12% Si₃N₄ in a 6-step interval, and 2 to 6%CuN₂O₆ in a two-step interval. The characterizations were made on the PM produced specimens using OM, EDS, XRD and hardness. The reinforcement particles were distributed uniformly is attributed by homogeneous mixer of matrix and reinforcements. The tests were carried out in accordance with ASTM Standards on the Al6063 alloy and its composites. The test findings show that as the reinforcing percentage of ceramic and inorganic compound is increased, properties such as hardness and density rise monolithically and considerably. The dispersion of Si₃N₄ and CuN₂O₆ reinforcement in the AA6061 matrix was ensured by x-ray diffraction patterns. In comparison to the base alloy, the hardness of AA6063/12%Si₃N₄/6% CuN₂O₆ improved by 88% due to the mismatch of thermal expansion between the Al matrix and reinforcement causes huge internal stress, causing the aluminium matrix to deform plastically to lodge the smaller volume expansion of Si₃N₄ and CuN₂O₆ particles. The dry sliding wear test was carried out on a tribometer with a pin-on-disc arrangement, and the findings show that the composite has a higher wear resistance. The Taguchi design of experiments was used to investigate the solution containing parameters employing an orthogonal array, the signal-to-noise ratio, and analysis of variance. The weight percentage of Si₃N₄/CuN₂O₆ compound and the relationship between wt% of reinforcement and applied load had the highest impact on composite wear resistance, accounted for 31.66%. Before and after the wear morphology during the wear test, images from a scanning electron microscope and energy dispersive microscopy were used to examine the manufactured composites.

Friction stir welding (FSW) is a solid-state technique used to join Al-Zn-Mg alloys effectively compared with other conventional welding methods. Al-Zn-Mg alloy was processed for welding because they significantly demanded various engineering applications. A novel method of this research work is to characterize the unique mechanical properties of Al-Zn-Mg alloy reinforced with 1 to 3 wt% of nano silicon carbide (nano-SiC) particles developed by novel interlock friction-stir welding. The process parameters chosen for welding are rotational tool speed 1100 rpm, weld speed 25 mm/min, and triangular pin profile. The weld joint properties such as tensile strength, yield strength, and hardness were tested per ASTM standard. The microstructure of weld joints was studied with XRD and optical and scanning electron microscopy. The existence of silica particles in the weld joints and uniformed and homogeneous distribution of the particulates in the weld was verified by EDS analysis and microstructure. Al-Zn-Mg reinforced with nano-SiC joints has better static properties due to intensive softening in the stir region. Al-Zn-Mg with 3 wt% nano-SiC exhibits maximum tensile strength, yield strength, and nugget hardness of 191 MPa, 165 MPa, and 171 HV. Weld microstructures showed a pinning mechanism because nano-SiC particles were used as reinforcement during friction stir welding.

This paper investigates the dry sliding wear behaviour of squeeze cast Al-Cu-Mg reinforced with nanographite metal matrix composites. The experimental study employed the Taguchi method. The Taguchi method plays a significant role in analyzing aluminium matrix composite sliding tribological behaviour. Specifically, this method was found to be efficient, systematic, and simple relative to the optimization of wear and friction test parameters such as load (10, 20, and 30), velocity (0.75, 1.5, and 2.25 m/s), and nanographite (1, 3, and 5 wt%). The optimization and results were compared with the artificial neural network. An orthogonal array L27 was employed for the experimental design. Analysis of variance was carried out to understand the impact of individual factors and interactions on the specific wear rate and the coefficient of friction. The wear mechanism, surface morphologies, and composition of the composites have been investigated using scanning electron microscopy with energy-dispersive X-ray spectroscopy. Results indicated that wt% addition of nanographite and increase of sliding speed led to a decrease in the coefficient of friction and wear rate of tested composites. Furthermore, individual parameter interactions revealed a smaller impact. The interactions involved wt% of nano-Gr and sliding speed, sliding speed and normal load, and wt% of nano-Gr and normal load. This inference was informed by the similarity between the results obtained ANN, ANOVA, and the experimental data.