Silicone rubber (SR) exhibits unique flame-retardant and fireproof properties and can be ceramized at high temperatures to cover the surface of an object that needs fire protection. In this paper, the influence of low-melting-point frit content on the expandable performance of SR has been investigated, and a decrease in the ceramization temperature with an increase in the frit content has been observed. The sample began to expand at 850 °C, and an expansion of 157% and compressive strength of 1.99 MPa were attained at 950 °C. The increased frit content resulted in a larger liquid phase, which covered the surface of the matrix owing to surface tension. This made the escape of small-molecule gaseous substances generated by decomposition difficult: this resulted in the expansion of the SR matrix. The relationships between composite compositions and expansibility as well as the degree of ceramization were also explored through performance tests. It was found that the formation of eutectic substances between frits and the matrix resulted in a decrease in the temperature of ceramization, which in turn contributed to the formation of highly intumescent ceramifiable SR. Full article

Electron beam additive wire-feed manufacturing of Cu-3wt.%S-0.8wt.%Mn bronze thin wall on a stainless steel substrate has been carried out at heat input levels of 0.19, 0.25, and 0.31 kJ/mm. The microstructures of as-deposited metal ranged from low aspect ratio columnar with equiaxed grain layers to zig-zagged and high aspect ratio columnar, as depended on the heat input. Post-deposition annealing at 900 °C for 6 h resulted in recrystallization of the high aspect ratio columnar grains with further grain growth by boundary migration. Pre-deformation by 10% thickness reduction and then annealing at 900 °C for 6 h also allowed obtaining recrystallized grain structures with less fraction of twin boundaries but higher fraction of high-angle ones, as compared to those of only annealed sample. Pre-deformation and ensuing annealing allowed simultaneous increasing of the ultimate tensile strength and strain-to-fracture. Full article

The hot workability behavior of antibacterial Ti6Al4V-5Cu alloy was investigated using a hot compression experiment in the temperature range of 790–1040 °C and strain rate of 10⁻³–10 s⁻¹ with a strain of 0.4. The deformation behavior of the alloy was characterized by Gleeble 3800 compression experiment, and the relationship among deformed microstructures and deformation parameters was established. The deformations of Ti6Al4V-5Cu alloy were temperature and strain rate-dependent. Higher temperature and lower strain rate made power dissipation efficiency (η) increase and reach 89%. The activation energies (Q) in the dual-phase (α + β) and single β phase regions were calculated as 175.43 and 159.03 kJ mol⁻¹, respectively. In the dual (α + β) phase region, with an increase in strain rate, flow-softening behavior was dominated, however in the single β phase region such as processing at 940 °C. Flow stress increased slightly in which work-hardening behavior was dominated (especially between strain rates of 10⁻³–1 s⁻¹). The deformation at various conditions exhibited different stress-strain profiles, providing an insight that work hardening and flow softening coexisted in Ti6Al4V-5Cu alloy. The relative intensity of oscillatory change in flow stress profile decreased as the strain rate decreased. The hot workability of Ti6Al4V-5Cu alloy was also accessed from the viewpoint of the sub-grain structure. Full article

The radiation effects of electrons and protons on the spectroscopic and optical properties of oxide glasses doped with Yb³⁺ in various glass systems were investigated to understand the impact of the glass composition on the glass photo-response. Changes in the optical and emission properties were seen after the radiation treatment, and the magnitude of the changes depended on the irradiation source and dose. For all the investigated materials, the absorption coefficients in the 200–550 nm range increase post-irradiation, revealing the formation of defects in the glasses during the irradiation. While the spectroscopic properties of the tellurite glass remain unchanged, a small reduction in the Yb³⁺ emission intensity was seen after irradiating the phosphate, borosilicate, and germanate glasses, indicating that a reduction of Yb³⁺ to Yb²⁺ might occur in these glasses during the radiation treatment. The changes in the optical and spectroscopic properties after proton irradiation are small as they are localized at the surface of the glasses due to the shallow penetration depth of the proton in the glass. Even though the doses are small, the electron irradiation produces larger changes in the optical and spectroscopic properties since the electrons penetrate the entire volume of the glasses. All the changes in the optical and spectroscopic properties of the glasses were successfully reversed after a short heat treatment revealing the reversible nature of the photo-response of the investigated glasses. Full article

Single crystals of Ce-doped (La,Pr)OBiS₂ superconductors, the multinary rare-earth elements substituted ROBiS₂, were successfully grown. The grown crystals typically had a size of 1–2 mm and a plate-like shape with a well-developed c-plane. The c-axis lattice constants of the obtained (La,Ce,Pr)OBiS₂ single crystals were approximately 13.6–13.7 Å, and the superconducting transition temperature was 1.23–2.18 K. Valence fluctuations of Ce and Pr were detected through X-ray absorption spectroscopy analysis. In contrast to (Ce,Pr)OBiS₂ and (La,Ce)OBiS₂, the superconducting transition temperature of (La,Ce,Pr)OBiS₂ increased with the increasing concentrations of the tetravalent state at the R-site. Full article

Numerous studies have shown that the geometry of micro-joints significantly affects the strength of the so joined timber element. The bending strength increases by creating a larger bonding area by increasing the length of the wedge joint. Although this type of joint has been successfully used for many years, it can still be troublesome to make. For these reasons, the present study investigated an easy-to-fabricate wedge joint, which we folded during the beams’ formation and glued with the same adhesive as the individual lamellas. Although the research has not fully answered all the questions relevant to both scientific and technological curiosity, it indicates the great potential of this solution. Following the principle adopted in the ongoing wood optimisation work, we concluded that the beams of the target cross-section should be produced, and it should only be possible to cut them to a certain length. In this approach, we only removed defects at critical points for the beam structure and, in this way, up to 30% of the timber processed could be saved or better utilised. Full article

Carbonated hydroxyapatite (CHAp) adsorbent material was prepared from Achatina achatina snail shells and phosphate-containing solution using a wet chemical deposition method. The CHAp adsorbent material was investigated to adsorb aqua Fe(II) complex; [Fe(H₂O)₆]²⁺ from simulated iron contaminated water for potential iron remediation application. The CHAp was characterized before and after adsorption using infrared (IR) and Raman spectroscopy. The IR and the Raman data revealed that the carbonate functional groups of the CHAp adsorbent material through asymmetric orientation in water bonded strongly to the aqua Fe(II) complex adsorbate. The adsorption behaviour of the adsorbate onto the CHAp adsorbent correlated well to pseudo-second-order kinetics model, non-linear Langmuir and Freundlich model at room temperature of a concentration (20–100 mg L⁻¹) and contact time of 180 min. The Langmuir model estimated the maximum adsorption capacity to be 45.87 mg g⁻¹ whereas Freundlich model indicated an S-type isotherm curvature which supported the spectroscopy revelation. Full article

A novel bypass coupling variable polarity plasma arc was proposed to achieve the accurate adjusting of heat and mass transfer in the welding and additive manufacturing of aluminum alloy. However, the physical characteristics and decoupled transfer behavior remain unclear, restricting its application and development. A three-dimensional model of the bypass coupling variable polarity plasma arc was built based on Kirchhoff’s law, the main arc and the bypass arc are coupled by an electromagnetic field. The model of current attachment on the tungsten electrode surface is included for simulating different heating processes of the EP and EN phases in the coupling arc. The distribution of temperature field, flow field, and current density of the bypass coupling variable polarity plasma arc was studied by the three-dimensional numerical model. The heat input on the base metal under different current conditions is quantified. To verify the model, the arc voltages are compared and the results in simulation and experiment agree with each other well. The results show that the radius of the bypass coupling arc with or without bypass current action on the base metal is different, and the flow vector of the bypass coupling arc plasma with bypass current is larger than the arc without bypass current. By comparing the heat transfer on the electrodes’ boundary under different current conditions, it is found that increasing the bypass current results in the rise in heat input on the base metal. Therefore, it is concluded that using bypass current is unable to completely decouple the wire melting and the heat input of the base metal. The decoupled degree of heat transfer is one of the important factors for accurate control in the manufacturing process with this coupling arc. Full article

To prevent endocochlear insertion trauma, the development of drug delivery coatings in the field of CI electrodes has become an increasing focus of research. However, so far, the effect of a polymer coating of PLLA on the mechanical properties, such as the insertion pressure and friction of an electrode array, has not been investigated. In this study, the insertion pressure of a PLLA-coated, 31.5-mm long standard electrode array was examined during placement in a linear cochlear model. Additionally, the friction coefficients between a PLLA-coated electrode array and a tissue simulating the endocochlear lining were acquired. All data were obtained at different insertion speeds (0.1, 0.5, 1.0, 1.5, and 2.0 mm/s) and compared with those of an uncoated electrode array. It was shown that both the maximum insertion pressure generated in the linear model and the friction coefficient of the PLLA-coated electrode did not depend on the insertion speed. At higher insertion speeds above 1.0 mm/s, the insertion pressure (1.268 ± 0.032 mmHg) and the friction coefficient (0.40 ± 0.15) of the coated electrode array were similar to those of an uncoated array (1.252 ± 0.034 mmHg and 0.36 ± 0.15). The present study reveals that a PLLA coating on cochlear electrode arrays has a negligible effect on the electrode array insertion pressure and the friction when higher insertion speeds are used compared with an uncoated electrode array. Therefore, PLLA is a suitable material to be used as a coating for CI electrode arrays and can be considered for a potential drug delivery system. Full article

Globally, there are several critical infrastructure networks (water and gas networks) whose disruption or destruction would significantly affect the maintenance of vital societal functions, such as the health, safety, security, and social or economic well-being of people. They would also have significant local, regional, and national impacts as a result of the inability to maintain those functions, and would have similar cross-border effects. The main objective of this article is to investigate by comparative numerical studies the structural response of three types of buried pipes made of different materials, primarily steel, concrete, and high-density polyethylene, resulting from the impact of the environment through exceptional external actions, such as explosions at the surface of the land in the vicinity of the laying areas. The dynamic transient analysis of the equation of motion with the application of the explicit integration procedure was performed with the ANSYS numerical simulation program. This study allows designers to solve complex problems related to the quality of the laying ground of water networks to canals. The knowledge accumulated gives us the possibility to correctly specify the optimal economic and technical value of the ratio between the laying depth of pipes and their diameter, the importance of the radius ratio of the pipe and the thickness of its wall, and, importantly, the improvement of the quality of the foundation ground. Following the results obtained, it is estimated that the optimal economic and technical value of the ratio between the laying depth of the pipes (H) and their diameter (D) is 3, regardless of the material from which the pipe is made. Full article

Due to the complexity of the biomolecules and titanium (Ti) combination, it is a challenge to modify the implant surface with biological cytokines. The study proposed a new method for immobilizing cytokines on implant surface to solve the problem of low osseointegration under type 2 diabetes mellitus (T2DM) condition. This new modified protein that connected Ti-binding artificial aptamer minTBP-1 with Insulin-like growth factor I (IGF-I), had a special strong affinity with Ti and a therapeutic effect on diabetic bone loss. According to the copies of minTBP-1, three proteins were prepared, namely minTBP-1-IGF-1, 2minTBP-1-IGF-1 and 3minTBP-1-IGF-1. Compared with the other modified proteins, 3minTBP-1-IGF-1 adsorbed most on the Ti surface. Additionally, this biointerface demonstrated the most uniform state and the strongest hydrophilicity. In vitro results showed that the 3minTBP-1-IGF-1 significantly increased the adhesion, proliferation, and mineralization activity of osteoblasts under T2DM conditions when compared with the control group and the other modified IGF-1s groups. Real-time PCR assay results confirmed that 3minTBP-1-IGF-1 could effectively promote the expression of osteogenic genes, that is, ALP, BMP-2, OCN, OPG, and Runx2. All these data indicated that the 3minTBP-1-IGF-1 had the most efficacious effect in promoting osteoblasts osteogenesis in diabetic conditions, and may be a promising option for further clinical use. Full article

In order to realize low energy consumption in cement and the recycling of solid waste, the phase composition and structure of waste mortar used to prepare a high belite cement clinker, instead of some other raw materials, have here been investigated, and the belite was activated by doping with SO₃. The results show that a good high belite cement clinker can be obtained using waste mortar, limestone, coal gangue, iron powder, or iron correction raw materials combined at 1350 °C for half an hour. The addition of SO₃ greatly increased the strength of the clinker in the early phase, and overall, the ratio of calcium to silicon in belite became higher, and more Al₂O₃ entered the belite; however, the generation of C₃S was inhibited somewhat, and the content of C₄AF also increased. This study offers guidance for the application of waste mortar and the activation of belite, which offers huge environmental and economic benefits. Full article

In this work, we investigate the influence of dehydration and subsequent rehydration of tendon fascicle bundles on their structural and mechanical properties by using distilled water, 0.9% NaCl, 10% NaCl, SBF, and double concentrated SBF (SBFx2). The properties of tendon fascicle bundles were investigated by means of uniaxial tests with relaxation periods and hysteresis for samples with various interfascicular matrix content, dissected from the anterior and posterior areas of bovine tendon. Uniaxial tests with relaxation periods and analysis of sample geometry and weight showed that dehydration alters the modulus of elasticity dependent on the interfascicular matrix content and influences the viscoelastic properties of tendon fascicle bundles. Tensile and relaxation tests revealed that changes resulting from excessive sample drying can be reversed by rehydration in an SBF bath solution for elastic strain range above the toe region. Rehydration in SBF solution led to minor differences in mechanical properties when compared to control samples. Moreover, anterior samples with greater interfascicular matrix content, despite their lower stiffness, are less sensitive to sample drying. The obtained results allow us to limit the discrepancies in the measurement of mechanical properties of wet biological samples and can be useful to researchers investigating soft tissue mechanics and the stability of transplant materials. Full article

To improve the durability of cement-based revetment materials serving in different positions relative to the water level, slag powder and polypropylene fibers were added into cement to prepare paste, mortar, and concrete. Based on three simulated experiments of high-humidity air, dry–wet cycles-coupled chloride erosion, and complete immersion-coupled chloride erosion, the half-year durability of cement-based revetment materials was investigated. An abundant amount of Ettringite containing chloride was formed in the pores of the cement, and its formation was accelerated by dry–wet cycles. Replacing 30% of cement by slag powder and adding 0.1 vol.% of polypropylene fibers helped concrete in the intertidal zone to obtain a compressive strength of 47.58 MPa after erosion, equal to 159% of the reference. Slag powder was found to induce cement to form Friedel’s salt and C-S-H with a more amorphous structure, increasing its chemical binding ability and physical adsorption ability to chloride ions, and reduce the chloride ions’ penetration depth of concrete from 22.5 to 12.6 mm. Polypropylene fibers controlled the direction of surface cracks to be perpendicular to the specimen’s sides. These findings lay a foundation for the design of high-durability cement-based revetment materials serving in costal environments. Full article

The hysteretic behavior of square concrete-filled steel tube (CFST) stub columns subjected to sulfate corrosion and freeze-thaw cycle is examined by numerical investigation. The constitutive model of steel considered the Bauschinger effect, and compression (tension) damage coefficient was also adopted for the constitutive model of core concrete. The experimental results are used to verify the finite element (FE) model, which could accurately predict the hysteretic behaviors of the CFST piers. Then, the effects of the yield strength of steel, compressive strength of concrete, steel ratio, axial compression ratio, and alternation time on ultimate horizontal load are evaluated by a parametric study. The results showed that the yield strength of steel and the steel ratio have a positive effect of hysteretic behavior. The compressive strength of concrete and alternation time significantly decreased the unloading stiffness which causes the pinching phenomenon. The yield strength of steel, compressive strength of concrete, and alternation time of environmental factors (corrosion-freeze-thaw cycles) has no obvious effect on the initial stiffness, while the steel ratio has a remarkable effect. The ultimate horizontal load increases with the increasing steel ratio, yield strength of steel and compressive strength of concrete. Meanwhile, the decrement of alternation time led to the increase of ultimate horizontal load. This suggests that the confinement coefficient and alternation time are the two main factors that impact the ultimate horizontal load. A formula which considers the reduction coefficient for the ultimate horizontal load of the CFST columns subjected to sulfate corrosion and freeze-thaw cycles is proposed. The formulae can accurately predict the ultimate horizontal load with mean value of 1.022 and standard deviation of 0.003. Full article