Given a set A and an abelian group B with operators in A, in the sense of Krull and Noether, we introduce the Ore group extension B[x; sigma B, delta B] as the additive group B[x], with A[x] as a set of operators. Here, the action of A[x]on B[x] is defined by mimicking the multiplication used in the classical case where A and Bare the same ring. We derive generalizations of Vandermonde's and Leibniz's identities for this construction, and they are then used to establish associativity criteria. Additionally, we prove a version of Hilbert's basis theorem for this structure, under the assumption that the action of A on B is what we call weakly s-unital. Finally, we apply these results to the case where B is a left module over a ring A, and specifically to the case where A and B coincide with a non-associative ring which is left distributive but not necessarily right distributive. (c) 2025 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
Wire Arc Additive Manufacturing (WAAM) has emerged as a promising metal additive manufacturing technique due to its high deposition rate, cost-effectiveness, and ability to build large-scale components. However, challenges such as porosity, poor mechanical properties, limited microstructural control, and residual stress hinder its full potential. Incorporating nanoparticles into the WAAM process has recently gained significant attention as a strategy to enhance material performance. This review provides a detailed and systematic analysis of the various types of nanoparticles used in WAAM, their methods of incorporation, effects on microstructure, mechanical performance, and functional properties of the built components. This review provides the first comprehensive classification and quantitative analysis of nanoparticle incorporation strategies in WAAM, systematically categorising 72 research articles across four distinct deposition strategies, including feedstock modification, interlayer application, direct melt pool injection, and ultrasonic dispersion. This work presents a comparative framework analysing the relative efficacy of different nanoparticle types (carbides, nitrides, and oxides) across multiple alloy systems, revealing that TiC emerges as the most extensively studied reinforcement. The review establishes that nanoparticle addition demonstrates positive influence on yield strength and ultimate tensile strength up to optimal concentrations, beyond which agglomeration-induced property deterioration occurs. Furthermore, the review identifies future perspectives for the optimized integration of nanoparticles in WAAM for high-performance manufacturing, design of multifunctional and hybrid reinforcement strategies, and adoption of AI-driven predictive modeling. The review discusses the industrial adoption barriers of the process. This systematic framework provides practical guidance for nanoparticle selection and process optimization, accelerating the industrial deployment of nanoparticle-reinforced WAAM technology.
Compromising in cyber security, especially regarding data leaks and single points of failure, pose a problem to the rapid growth of the Internet of Things (IoT). A solution for these issues is Blockchain and Federated Learning (FL) integration, which offer a more private and decentralized method for ensuring the security of IoT devices. This integration improves the integrity of data autonomously, while authentication and secure model aggregation block any attempts to tamper. Moreover, FL allows Artificial Intelligence (AI) to be trained on devices, making the exposure of data less likely. In this paper, we analyse the attack surface and emerging vulnerabilities of Blockchain-FL based IoT systems while constructing a taxonomy of the threats posed. They focus on novel security frameworks aimed at constructing next generation IoT system infrastructure, which is scalable, robust, intelligent and above all, secure.
In present study high temperature tensile behaviour of IN718 manufactured through electron beam melting (EBM) has been studied. As-built (A-1) sample contains defects such as porosity, shrinkage cracks etc. which were eliminated through hot isostatic pressing (HIP). Sample was subjected to two different post treatments (i) hot isostatic pressing (HIP) followed by heat treatment (A-2) and (ii) HIPing and heat treatment inside HIP vessel in a single cycle (A-3) to eliminate the defects as well as to precipitate out strengthening phases. Tensile tests were conducted at 600 degrees C, 650 degrees C and 700 degrees C at different strain rates (epsilon(center dot)) varying from 2.50 x 10-5 to 2.50 x 10-3 /s on samples in as built (A-1) along with heat treated conditions. The yield strength (YS) of A-1, A-2 and A-3 sample at 650 degrees C and 2.50 x 10-4 /s was 744 MPa, 936 MPa and 883 MPa respectively. Both the heat treated samples exhibited desired yield strength at 650 degrees C (862 MPa as per AMS5663M standard). Serrations were present in the plastic region of tensile curves indicating dynamic strain aging (DSA). B type and C type serrations were present depending on the test conditions. The apparent activation energy (Q) for appearance of serrations was calculated using critical strain method and intercept method. Apparent activation energy for B type serrations in A-1, A-2, and A-3 sample varies from 150 to 187 kJ/mol, 191-222 kJ/mol and 154-205 kJ/mol respectively while the Q for C type serrations varies from 132 to 184 kJ/mol, 168-270 kJ/mol and 154-202 kJ/mol for A-1, A-2, and A-3 sample respectively. These values are well within the range of Q required for solute atoms (Fe, Cr, Mo, Nb) to diffuse in nickel. Energy filtered transmission electron microscopy (EFTEM) maps of tensile tested samples suggest that Mo and Nb are accountable for the appearance of B type and C type serrations in EBM IN718. It was observed that Fe and Cr do not have a significant effect in appearance of these serrations.
Friction stir consolidation (FSC) is a relatively new solid-state recycling process developed to obtain small billets from metal chips in a unique working step. One of the main unresolved issues in solid-state recycling processes (e.g., Friction Stir Extrusion, Continuous Friction Extrusion, etc.) is the understanding of the effects of the oxide layers initially present on the chips on the final recycled products. In this paper, FSC was conducted on AA 6082 aluminum chips with different rotational speeds of 1000, 1500, 2000, and 2500 rpm. Microstructural evolution was examined using scanning electron microscopy (SEM) integrated with electron backscattered diffraction (EBSD). Backscattered electron (BSE) images showed that fine equiaxed grain structures were developed through the microstructure of the processed samples. Intermetallic compounds were broken down by the stirring action of the rotating tool, leading to the formation of micro- and nano-sized second-phase particles. The presence of loose high-angle grain boundaries connected to low-angle grain boundaries confirmed the occurrence of continuous dynamic recrystallization (CDRX). Texture analysis revealed the development of simple shear texture components of face-centered cubic (FCC) structured materials with the Oblique Cube component. Hardness measurements revealed that the hardness of the microstructure increased with a greater proportion of low-angle grain boundaries (LAGBs) and higher texture intensity.
