Hydrogen, as an emission-neutral energy carrier, plays a key role in establishing a circular energy system and holds the potential to decarbonize numerous technical sectors. However, most hydrogen production to date has been derived from fossil fuels such as gray hydrogen. In contrast, sustainable green hydrogen can be generated by water electrolysis using renewable electrical energy. Yet, this remains economically unviable due to the comparatively low efficiency and high costs of precious cathode materials such as platinum. Hence, Raney nickel-type cathodes present a cost-efficient alternative due to their catalytic material properties. In perspective, thermally sprayed precursors are promising thanks to their characteristic open-porous structure, which is beneficial in applications such as atmospheric plasma spraying. Subsequent leaching of aluminum-rich phases chemically activates the surface and a nickel structure with a high specific surface area remains, which will enhance cathode reactivity. Prior to spraying, however, an appropriate powder feedstock must be identified. Also, the production by powder atomization is to be evaluated in order to meet the requirements for the indented application, including chemical homogeneity and composition, powder morphology and microstructure, phase formation, as well as particle size distribution. Therefore, in this study, preselected metal wires were arc-melted to rods with various compositions and subsequently ultrasonically atomized. Furthermore, bulk specimens were produced by spark-plasma sintering with low oxidation and low porosity. The material properties were examined along this process chain and related to the required functional properties, providing a comprehensive assessment of this approach.

In the conventional building procedure, numerous circumstances may be discovered regarding building types composed of a lower and older reinforced concrete (r/c) component and an upper and newer steel part, referred to as a "hybrid" building. Established principles of seismic design provide comprehensive instructions for the resistant design of structures built using a single material everywhere. The present seismic norms do not give explicit design and detailing requirements for vertical hybrid structures. There needs to be more investigation in existing research, addressing thisscientific gap. The current study attempts to fill this knowledge gap on hybrid construction performance under successive ground motions, which have been reported in research worldwide in terms of seismic structural performance. Three-dimensional representations of hybrid r/c-steel building frames are subjected to successive ground stimulations across the horizontal and vertical directions, implementing a non-linear response of the frame components over time. The bottom r/c part of the hybrid structures is described as relating to a previous construction using an essential approximation here. Furthermore, two limit interconnections of the structural steel component to the concrete one are identified for investigation in non-linear time history analysis. An evaluation of the arithmetic analysis outcomes of the hybrid frames considering the two limit interconnections is performed. The analysis diagrams of the present dynamic investigations of the 3D hybrid frames exposed to successive ground motions provide helpful insights that offer guidelines for a better earthquake-resistant design of the “hybrid” building form, which does not fall within the scope of the present standards despite being frequently used.

This study conducted an exploration of the influence exerted by polymer ANP at various concentrations on Cu electrodeposition onto brass surfaces. This endeavor sought to illuminate the effects of the ANP additive while meticulously scrutinizing the morphology of Cu electrodeposits. To achieve this, a multifaceted approach was adopted, integrating techniques such as scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM). Cyclic voltammetry served as a pivotal tool in unraveling the Cu electrodeposition mechanism, unraveling an irreversible system characterized by diffusion-controlled kinetics. The SEM/EDS and AFM analyses unveiled compelling insights, showcasing that the incorporation of ANP resulted in an enhancement in the quality of Cu electrodeposits. This enhancement was notably reflected in the improved roughness and crystallite size of the deposits. Moreover, electrochemical measurements were conducted to probe ANP's influence on the resistance of Cu electrodeposits within a 3.5 wt% NaCl medium. These measurements brought to light a significant increase in the polarization resistance of the Cu deposit in the presence of ANP. This elevation underscored the heightened corrosion resistance conferred by ANP, particularly in marine environments notorious for their corrosive nature. The incorporation of ANP into the electrodeposition process heralded noteworthy advancements in both the quality and resilience of Cu electrodeposits. The enhanced morphology and increased resistance to corrosion observed in the presence of ANP underscored its potential as a beneficial additive in the realm of materials science, particularly for applications demanding durability in challenging environments like marine settings.

In this study, we successfully synthesized silicon nano-dioxide by modifying the conventional sol–gel method, eliminating the use of water as a hydrolysis agent and using oxalic acid as a reagent and structural reaction agent. The analytical results reveal that the product has a high purity and a coherent molecular structure. X-ray diffraction (XRD) analysis revealed a broad peak with an angle of 22.5°, indicating the morphosyntactic structure. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of silicon dioxide bonds, while atomic force microscopy (AFM) revealed significant differences in surface morphology. In contrast to the typical spherical shape of silicon nano-dioxide, the surface of the synthesized silicon dioxide shows a mountainous terrain with marked peaks and valleys, with the distance between the lowest and highest points being less than 10 nanometers, indicating the small size of the nanocrystals. Ultraviolet (UV) spectroscopy revealed a distinct peak at a wavelength of 266 nm, corresponding to a small energy gap of 3.8 electron volts. This result shows that the synthesized solid has a semi-conductive character, unlike conventional silicon oxides, which are characterized by their insulating properties. Additionally, the unique morphology of the synthesized silicon dioxide nanoparticles suggests potential applications in various fields such as electronics, photonics, and catalysis. The modified sol–gel method employed in this study offers a novel approach to synthesizing silicon dioxide nanoparticles with tailored properties, paving the way for future research and development in nanotechnology.

In recent years, studies have demonstrated that grain boundary (GB) migration is a three-dimensional (3D) process, characterized by a 3D mobility tensor. In this presentation, we introduce a recently developed 3D interface random walk theory, which provides a framework for extracting intrinsic GB mobility and shear coupling tensors based on the random walk behavior of GB positions. This theory enables a mathematical proof of the symmetry of the GB mobility tensor in the case of overdamped GB migration. The theory and its conclusions align with molecular dynamics simulation results, and the computed shear coupling aligns closely with predictions from disconnection analysis. Additionally, we propose the fast-adapted random walk (FAIRWalk) method, enabling the efficient extraction of the GB mobility tensor from fewer simulations while maintaining high accuracy. Building on this advancement, we conducted an extensive survey of the mobility, shear coupling, and activation energy of the migration of 388 coincidence-site lattice Ni GBs in the Olmsted database. Several intriguing phenomena were observed, including temperature-induced sudden emergence, disappearance, or inversion of shear coupling; GBs with "zero" normal mobility but high shear mobility; and a non-linear relationship between activation energy and mobility. These findings challenge the traditional understanding of GB migration and warrant further investigation.

Due to its large hydrogen capacity (10.1 wt.%), aluminium hydride (AlH₃) is considered as a possible material for on-board hydrogen storage applications. However, several factors, such as its high decomposition temperature and sluggish desorption kinetics, limit this benefit and render this material unmarketable. To overcome these limitations, numerous studies have been conducted, such as using mechanical milling to reduce the particle size and adding dopants or catalysts. In this work, the effect of metals (Ni and Fe) on the dehydrogenation properties of AlH₃ has been investigated for the first time. The results show that Ni is a better catalyst than Fe when it comes to lowering the initial decomposition temperature and speeding up the process of AlH₃ desorption. The 10 wt.% Ni-doped AlH₃ sample's starting decomposition temperature dropped from 130 °C to 80 °C compared to that of as-milled AlH₃. In the desorption kinetic measurements at 100 °C, the 10 wt% Ni-doped AlH₃ sample desorbed about 6.7 wt% of H₂ in 20 min compared to the 4.5 wt% desorption exhibited by the as-milled AlH₃. After Ni was added, the activation energy for the dehydrogenation process of AlH₃ that was determined by Kissinger analysis was decreased. From the X-ray diffraction analysis, we found that Ni did not react with AlH₃ during the mechanical milling and heating (desorption) processes. Ni is believed to play a catalytic role by inducing Ni-H interaction and weakening Al-H bonding, which improves the dehydrogenation storage properties of AlH₃.

The application of metallic materials in environmental remediation has gained increasing attention due to the need for sustainable solutions to pollution. This study investigates the preparation and application of illite impregnated with iron (Fe) and indium (In) as a heterogeneous catalyst for the degradation of malachite green, a persistent and toxic dye used in industrial processes.

The Fe/In-impregnated illite catalyst was synthesized using a wet impregnation method, enabling the effective incorporation of metal ions into the clay matrix. Advanced characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX), were employed to confirm the structural and compositional modifications.

The catalytic activity of the synthesized material was evaluated through dye degradation experiments under varying reaction conditions, such as pH, dye concentration, and temperature. The results demonstrate that the Fe/In-illite catalyst achieved a degradation efficiency exceeding 97% for malachite green under optimal conditions. the kinetic studies revealed a pseudo-first-order reaction mechanism, highlighting the synergistic effect of iron and indium in enhancing the oxidative degradation process.

This work underscores the potential of combining metallic chemistry with natural clays to develop cost-effective and eco-friendly catalysts. The findings contribute to advancing the field of metallic materials chemistry for environmental and industrial applications.

Material anisotropy is an important topic to consider when using additive manufacturing for industrial applications. Since the products fabricated by wire arc additive manufacturing (WAAM), a metal additive manufacturing technology used to fabricate large parts, are sometimes used in parts that require a specific level of strength required by industry, it is essential to clarify the characteristics of these products for their industrial application. Furthermore, it should be noted that the fabrication of complex shapes such as blades by WAAM cannot be used for industrial applications, because of defective fabrication if appropriate fabrication conditions are not used. However, many studies have focused on simple shapes such as flat plates; thus, there is a problem in that evaluations have not always been conducted under conditions that enable the fabrication of complex shapes. In this study, an investigation was conducted into the material anisotropy of Inconel 718 under conditions where impeller blades can be fabricated by WAAM. An Inconel 718 wall was fabricated by WAAM, and tensile specimens were cut from the wall. Two different directions were used for the cutout: vertical and horizontal. Tensile tests were performed using these two types of specimens with different cutout directions. A comparison of the tensile test results showed that the difference between tensile strength and elongation at break was less than 3%. This indicates that the material anisotropy of Inconel 718 without heat treatment is small compared to other materials additionally produced by WAAM.

One approach to improving the manufacturing technology of turbomachinery is the application of metal additive manufacturing. Several studies have shown that wire arc additive manufacturing (WAAM) can be used to improve fabrication and reduce the environmental impact of impellers and other components with blades. To further advance manufacturing technology using WAAM, it is necessary to evaluate not only additive manufacturing using a single material, but also additive manufacturing combining multiple materials. However, there are only a limited number of examples of such studies. Therefore, there is a problem in that sufficient knowledge for industrial applications has not yet been obtained. The objective of this study is to evaluate the mechanical properties of a multi-material, stainless steel SST316L and nickel-based alloy, Inconel 718, fabricated by WAAM, when applied with heat treatment. To fabricate the test piece, a wall combining the two materials was fabricated by additively manufacturing an Inconel 718 wall made via WAAM and then additively manufacturing a SST316L wall on top of the Inconel 718 wall made via WAAM. A test piece was obtained by cutting out tensile test specimens from the wall. The specimens were subjected to several types of heat treatments and tensile tests were performed to analyze differences in their mechanical properties. The heat treatments were solution heat treatment, which is generally used for austenitic stainless steels, and aging treatment, which is generally used for Inconel 718. As a result, it was found that the multi-material under any of the heat treatments has mechanical properties that can be concluded to be industrially applicable.

Using machine learning approaches such as the artificial neural network (ANN) model, the factors influencing the leaching of copper from contaminated soil using sulphuric acid were determined. The feed-forward back-propagation (BP) algorithm was used for the development, training, and prediction of the artificial neural network model. The pH of the solution, acid concentration, soil-to-liquid ratio, and stirring speed were used as input variables, while the amount of copper (II) leached was used as the output. To build and train the model, 21 datasets were taken from the leaching experiments. We looked at neural networks with one to nine hidden layers to find the one with the best agreement and to find the one that could reduce the discrepancy between the predicted and measured values. A proportion of 70% of data were used for training, 15% for testing, and 15% for validation. During the regression analysis of the four inputs, nine hidden layers, and one output design, the R² value for training was 0.997, that for validation was 0.996, and that for testing was 0.997. The algorithm used was Levenberg–Marquardt with membership 11-11-11-11. The corresponding MSE values were 0.121, 0.133, and 0.105. The findings indicate that the artificial neural network holds great promise for predicting the leaching of copper (II). The results showed that the ANN model's performance improved as the number of hidden layers increased.