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Sulfate-induced degradation is one of the most important factors influencing the durability of concrete. The paper aims to clarify the transport-deterioration process of sulfates in concrete and thus to explain the mechanism and the deterioration of concrete by sulfates.

This paper presents an experimental study into the evolution of the transport-deterioration process of sulfate ions in concrete in a pure soaking environment.

The microscopic morphology of individual concrete layers at different depths and the change law of the sulfate ion concentration at the corresponding depths were investigated for different exposure times. Furthermore, the relationship between the changes in microstructure and the transport characteristics of the sulfate ions was studied.

A method to calculate the cracking level sulfate ion concentration was proposed.

Gas evolution within lithium-ion batteries (LIBs) gives rise to safety concerns that question their applicability. The gas evolution is not only the result but also the inducement of performance deterioration of LIBs. In this paper, the growth characteristics and dynamic behavior of gas bubble on the electrode surface are studied, and the interference mechanism of gas evolution on Li-ion diffusion or Li-ion conduction within LIBs is discussed and validated by the numerical simulations.

First, the mathematical models and simulation method are established. The growth and flow of gas bubble in the serpentine channel on electrode surface, which results from the gas-liquid flow and the effects of surface tension, is modeled by using the multi-phase Navier-Stokes and the volume of fluid method. Integrating Butler–Volmer and Fick’s law, the mathematical model of ions transport in the electrochemical cell is set-up. Second, the motion of gas bubble is tracked, and the variations of bubble shape and characteristic parameters with time are obtained by the computed fluid dynamics (CFD) method.

Based on the CFD results, the battery models and electrochemical simulations are carried out to analyze the ionic transport characteristics. The results show that the microstructural morphology such as the serpentine channel shape and size on electrode surface are important aspects for the gas bubble growth and the local ionic transport. Li ions significantly accumulate at one side of the gas obstacle, hindering the ionic diffusion normally. When the gas bubble blocks the electrolyte, the passage of ions from the positive to the negative is interrupted, and the open circuit zone of the electrochemical cell is formed.

The gas evolution within LIBs is not only a result but also an inducement of its performance deterioration. The primary issues in this study are the growth characteristics and dynamic behavior of gas bubble on the electrode surface, providing the knowledge for the interference mechanism of gas evolution on ionic transport and ultimately leads to significant increase of battery resistance.

The paper aims to illustrate the two kinds of analysis approach for which finite element method (FEM) can be successfully employed: the Poisson-Nernst-Planck (PNP) model and the Langevin-Lorentz-Poisson (LLP) one.

The approach of this work is to try making a survey of the use of the FEM in the modelling of charge transport/ion flow across membrane channels, in particular for the PNP analysis and for a particle based model such as LLP model.

In this paper, the two kinds of analysis approach for which FEM can be successfully employed, the PNP model and the LLP one, have been shown. In both cases the FEM is extremely useful to carry out these analysis and the simulation results obtained are in good agreement with experimental results.

The value of this paper is to demonstrate the FEM is extremely useful to carry out analysis and results which are in good agreement with experimental ones.

This paper aims at analyzing the potential of new materials in magnesium-ion batteries (MIBs) with a particular focus on options for electrodes and electrolyte solutions while also carefully considering the barriers to their entry in this application for MIBs, with a particular focus on the material options for electrodes and electrolyte solutions.

Potential materials for MIBs were examined for sustainability, safety and efficiency to develop the sustainable and well-working MIBs.

For anode materials, the use of Mg-bismuth alloys has shown promise, whereas Chevrel phases or layered molybdenum disulfide have potential as cathode materials. Potential electrolytes range from traditional materials to the development of tailored solid-state and liquid-based options.

This study considers the growing need for Mg-based ion batteries, as well as the need for suitable electrode and electrolyte materials and analyzes suitable options.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2023-0081/

The purpose of this study is to develop a additive manufacturing (AM) process for the fabrication of ionic polymer–metal composite (IPMC) devices with complex designs that would be time-consuming to replicate using conventional manual methods. These IPMC devices have considerable potential in electroactive polymers (EAPs) and soft actuators.

This paper presents a novel three–dimensional (3D) AM technique to develop IPMCs. Digital light processing (DLP) fabrication of soft EAPs was undertaken using a vat-based AM method, followed by deposition of cost-effective outer silver electrodes.

DLP-fabricated devices were compared to conventional Nafion™-117 devices. DLP layer-by-layer fabrication of these devices allowed for good resolution for a range of printed objects. Electrical actuation of the DLP-produced IPMCs showed tip displacements of up to 3 mm, and greater actuation was seen in the presence of lithium rather than magnesium cations. The IMPCs showed good ion exchange capacities, while electrochemical analysis showed the reversible formation and removal of AgCl layers in addition to ion movement.

The AM of these devices allows for rapid prototyping as well as potential use in the development of multiple degrees of freedom actuators and devices.

An original resin formulation was developed for DLP 3D printing. This formula is chemically distinct from the conventional Nafion™-117 membranes that can be purchased. Additionally, this method allows for the manufacture of complex objects that would be difficult to machine by hand. These findings are of value to both the fields of polymer chemistry and AM.

This paper aims to focus on the preparation of a cation exchange filament for three-dimensional (3D) fused deposition modeling (FDM). The polymeric binder was mixed with the selected conventional cation exchange resin and a filament was prepared using a mini extruder. Filaments were tested by mechanical properties, chemical properties, quality and melt flow index. Samples were prepared from granulate using a press, which were tested for electrochemical properties, thermal properties. The best result of ion exchange capacity (IEC) up to 3.0 meq/g of the dry matter was achieved with filament fill 65%. Permselectivity results above 90% were determined for 55%–65% filling of the cation exchanger. The results obtained are a promising step for the preparation of 3D printed cation exchange membranes (CEMs) with a defined structure.

The prepared granulates and filaments were evaluated using mechanical, rheological and thermal properties.

The prepared cation exchange filament can be used for the 3D printing process. The best result of IEC up to 3.0 meq/g of the dry matter was achieved with filament fill 65%. Permselectivity results above 90% were determined for 55%–65% filling of the cation exchanger, and area resistances 3.0 Ocm² and specific resistances around 57 Ocm for 65% filling of the cation exchanger. The results obtained are a promising step for the preparation of 3D printed CEMs with a defined structure.

The prepared cation exchange filament. Using new materials for 3D print of cation exchange membrane. Production without waste. The possibility of producing 3D membranes with a precisely defined structure. Processing prepared filaments using a cheap FDM 3D printing method. New direction of membrane formation.

The purpose of this paper is to study the effect of surface salt spray duration on the fretting wear and electrochemical corrosion behaviors of Inconel 690 alloy.

A high-temperature steam generator was applied to salt spray test samples, a fretting wear rig was used to realize the damage behavior tests, an electrochemical workstation was applied to analysis the changes of each sample’s corrosion dynamic response before and after fretting wear.

The thickness of the oxide film that formed on sample surface was increased with the salt spray duration, and somewhat it could act as lubrication during the fretting wear process; however, the corrosive chloride would accelerate the fretting mechanical damage behavior.

In a salt steam spray condition, the fretting tribo-corrosion behaviors of Inconel 690 alloy surface was studied.

The rate of diffusion controlled dissolution of copper powder in acidified chromate solution under forced convection conditions was studied. Variables investigated were, rotational speed, initial concentration and physical properties of the acidic solution. Increasing the initial concentration was found to decrease the volumetric mass transfer coefficient. Within the range w = 150–600 rev/min, the volumetric mass transfer coefficient was found to be directly related to the rotational speed according to the following k a w0.6 On the other hand, the volumetric mass transfer coefficient was found to be inversely proportional to the kinematic viscosity of the solution according to the following relation k a v0.7

The surface insulation resistance (SIR) test has traditionally been performed by taking measurements at certain points during a seven‐day test under well established environmental conditions. The work reported here explores the influence of test temperature and humidity when using a typical resin flux, a weak organic flux and glycol based fluxes when sampling SIR patterns every ten minutes. Results indicate that some fluxes are very sensitive to the test temperature, with volatilisation of flux residues an important issue. The frequent monitoring of the results also permitted the detection of dendrites during the SIR test. The results clearly show the importance of selecting the correct testing conditions and the benefit of frequent monitoring.

Modular construction is widely used for residential buildings of 4 to 8 storeys. In the context of open building systems, modular construction provides a systemised approach to design in which the benefits of prefabrication are maximised. There is demand to extend this form of construction to more than 12 storeys for residential buildings. This paper presents a review of modular technologies, and describes load tests and analysis on light steel modular walls that are used to justify the use of light steel technology to support higher loads.

For taller modular buildings, the effect of installation and geometric inaccuracies must be taken into account and it is proposed that maximum out of verticality of a vertical group of modules is 50mm relative to ground datum. Using these geometric tolerances, the notional horizontal force used to evaluate stability of a group of modules should be taken as a minimum of 1% of the applied vertical load on the modules. Robustness to accidental load effects is important in all high-rise buildings and it is proposed that the tie force in the connections between modules should be taken as not less than 30% of the total vertical load applied to the module in both horizontal directions.