This paper investigates the solitary wave solutions for the perturbed nonlinear Schrödinger equation with six different nonlinearities with the essence of the generalized classical derivative, which is known as the beta derivative. The aforementioned nonlinearities are known as the Kerr law, power, dual power law, triple power law, quadratic–cubic law and anti-cubic law. The dark, bright, singular and combinations of these solutions are retrieved using an efficient, simple integration scheme. These solutions suggest that this method is more simple, straightforward and reliable compared to existing methods in the literature. The novelty of this paper is that the perturbed nonlinear Schrödinger equation is investigated in different nonlinear media using a novel derivative operator. Furthermore, the numerical simulation for certain solutions is also presented.

Metal Additive Manufacturing (MAM) process has been established as an industrial process for customized and intricate metallic components. It is one of the growing technologies proving its potential in numerous fields by introducing the latest processing methods. The significant growth in this technology is partially fueled by its ability to manufacture parts that could be performance-beneficial and commercially utilizable in various industries. The adaptability of metal AM processes has prompted innovation across various industries with applications spanning defense, aerospace, medical, dental, automotive, and oil & gas sectors. Each industry benefits from the unique abilities of metal AM; for instance, material efficiency, design flexibility, lead time reduction, and the creation of lightweight and complex structures that were unachievable through traditional methods can now be achieved. Therefore, this review article analyzes metal AM, describing its types, technological challenges, environmental & business considerations, energy consumption, applications, and future trends. Initially, the article introduces primary categories of metal AM, elaborating their mechanism and working principles, later, it focuses on the industrial contributions of metal AM, technological challenges, and business considerations. The outlook of this technology highlights emerging materials and technologies, such as the inclusion of machine learning (ML) and artificial intelligence (AI) to predict defects, optimize process parameters, and enhance the quality of products. Furthermore, advanced materials like high entropy alloys (HEAs) are being discussed to broaden the functionality of AM parts. Metal AM is playing a critical role in shaping the future of manufacturing by offering customization, efficiency, and sustainability in the industries. The article aims to provide a general understanding of metal AM while highlighting key technological advancements and future research directions to expand its applications in various sectors further.

The stability and reliability of braking system are essential factors for the safe operation of high-speed trains. In the proposed work, tribological properties of a newly developed brake disc material namely BD-1 were studied considering the thermal-mechanical effects, as well as the evolutions of wear debris, were particularly examined. The tribological properties were also compared with an existing commercial brake disc material namely BD-2 in text. Friction and wear tests were carried out on BD-1 and BD-2 against a commercial brake pad material (BP) to simulate the real emergence braking conditions of a 350 km/h high-speed railway. The thermal-mechanical coupling effects of the friction velocity, wear mass, temperatures and the friction coefficient were investigated. Local wear track and wear debris were analyzed by using SEM and EDS. Results show that the shape and size of wear debris evolve as the dominant wear mechanism varies during braking tests. As the sliding speed increases from 250 to 1250 rpm, the debris may become fine particles, then into a mixture of lamellar shape and flake shape, and finally becomes fine particles again at high speed. The maximum size of wear debris is first from 20 μm to 65 μm, and then down to 10 μm. As the local area temperature increased by more than 400 °C, debris adhere to the surface forming an adhesive layer that may act as a lubricant. Debris may help to form an adhesive lubrication layer and undertake plastics defor-mation at the speed range of 500–1000 rpm. The local area temperatures prompted the wear debris adhesion and oxidation. After reaching a certain speed limit, a uniform third body appears to protect the material surface from high speed and high temperature. Results suggested that the BD-1 could be a good candidate braking material for high-speed railway applications.

Fused Filament Fabrication (FFF) is a widely embraced material extrusion (MEX) additive manufacturing (AM) process to produce complex three-dimensional structures, and it is typically used in the fabrication of biodegradable polymers for biomedical applications. However, FFF as a fabrication process for blended polymeric materials needs to be optimized for enhanced mechanical properties. In this work, biodegradable polylactic acid (PLA)/polyhydroxyalkanoate (PHA) dog-bone and notched specimens are printed to determine optimum printing parameters for superior mechanical properties in FFF additive manufacturing. The effect of layer thickness, infill density, and printing bed temperature on mechanical properties is investigated by employing a design of experiments (DoE) approach using response surface methodology (RSM). Experimental results showed the significance of the opted parameters for mechanical properties of the PLA/PHA blend. Then, optimum values for layer thickness, infill density, and printing bed temperature are identified for tensile and impact strength and an empirical relationship between parameters is formulated for low density and cost-effective fabrication. Finally, the analysis of variance (ANOVA) is performed to check the adequacy of the model for the influence of process parameters and their mutual interactions. The verification experiments validated the adequacy of the proposed model for PLA/PHA blend in FFF additive manufacturing.