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A20X is an advanced and high-strength additive manufacturing aluminum alloy with promising applications in several fields, including aerospace and aeronautics. However, its assembling through fusion welding technologies poses challenges due to the detrimental effects of melting and solidification. Friction stir welding offers a promising solution for joining A20X, producing components with superior mechanical properties while preserving the engineered microstructures. This study investigates the influence of friction stir welding on the quality of butt joints made of 4 mm thick additively manufactured A20X plates produced by laser powder bed fusion. Different rotational (900 and 1500 rpm) and welding speeds (100 and 500 mm/min) were tested to evaluate the influence of the joining process on weld quality (mechanical strength, microstructures, welding defects, and surface roughness). Friction stir welding maintains a very fine microstructure in the welds, with only a slight reduction of the mechanical strength compared to the base material (335 MPa vs. 385 MPa on average). The hardness of the welded joints increases, attributed to local aging caused by the heat input during the joining process. Lower tool rotation and welding speed result in tunnel defects, notably reducing joint strength. 3D X-ray computed tomography reveals that the metal stirring occurring during the joining process notably reduces the intrinsic porosity of A20X. It also breaks up Ti borides and promotes the growth of Al-Cu precipitates within the stir zone. The fractographic analysis highlights the ductile behavior of A20X after welding, emphasizing the critical role of welding parameters in joint integrity. [ABSTRACT FROM AUTHOR]

The dye removal effect of the anisotropic polysaccharide-ZIF-8 aerogel via adsorption and catalysis was observed, highlighting the great potential of the hybrid aerogel as a highly effective, sustainable, and low energy-consuming environmental remediation material. The hybrid aerogel with remarkable mechanical strength has excellent prospects for regeneration to extend its lifespan. [Display omitted] Assembling microscopic metal–organic frameworks into macroscopic polymeric scaffolds to develop highly renewable materials has been a promising yet challenging area of research. Herein, chitosan (CS) blended with nano-cellulose (NC) was unidirectionally transformed into an aerogel with oriented macropores and then biomineralized with zeolite imidazolate frameworks-8 (ZIF-8) to form a hierarchical structured chitosan-nanocellulose/zeolite imidazolate frameworks-8 (CS-NC-ZIF-8) hybrid aerogel. Incorporating ZIF-8 significantly increases the versatility and mechanical strength with a Young's modulus of 14.18 MPa of the CS-NC aerogel. The incorporation of ZIF-8 into the aerogel not only enhances its adsorption capacity for methylene blue, rhodamine B, acid fuchsin, and methyl orange, but also facilitates the generation of electrons from water that can be transferred to degrade > 90 % of malachite green within 90 min in each catalytic cycle, and this capability was maintained for at least 10 consecutive cycles. Remarkably, the hybrid aerogel was highly renewable after the adsorption of cationic dyes and catalytic removal of malachite green. With its facile production process, high removal efficiency, affordable and green nature, and excellent regeneration feasibility, the CS-NC-ZIF-8 aerogel stands as a promising solution for addressing challenges associated with dye-contaminated water treatment. [ABSTRACT FROM AUTHOR]

The potential of combining stratified paper forming with pulp fractionation was investigated to improve the balance between low density, which enhances water absorbency and softness, and the dry strength of tissue papers. The selected fractionation approaches allowed us to separate especially stiff, low-fibrillated fibers (A fractions) from flexible, fibrillated fibers containing fines (detached segments of fibers, fibrils, or lamellae fragments) (B fractions). After characterizing the morphological properties of each fiber fraction, 20 g/m2 model papers were produced with and without wet pressing to tune the paper density. At a density of 0.3 g/cm³, the tensile breaking stress of B papers was at least three times higher than that of A papers. The strain at break of B papers was also close to two times higher than that of A papers. Interestingly, bilayer papers A/B exhibited breaking stress values intermediate between those of A and B papers, while native pulp papers, i.e., without fractionation and stratified forming, followed the trend of A papers. Notably, bi-layering the paper improved the breaking stress by up to twice as much without increasing the paper density, which could be highly beneficial in improving the balance of properties in tissue paper grades. [ABSTRACT FROM AUTHOR]

Purpose: This study sought to evaluate the biomechanical properties of the interface between the rotator cuff and the semicircular humeral ligament or rotator cable (RCa) using histological and biomechanical techniques. Methods: Out of 13 eligible cadaver specimens, 5 cadaver shoulders with an intact rotator cuff were included, 8 were excluded due to an injured rotator cuff. The histological study enables us to describe the capsule-tendon interface between the infraspinatus tendon (IST) or supraspinatus tendon (SST) and RCa, and to detect loose connective tissue layers to determine their precise location and measure their length along the interface. The biomechanical study sought to characterize and compare the mechanical strength of the IST-RCa versus SST-RCa interfaces. Results: The average thickness of the RCa was 1.44 ± 0.20 mm. The histological study revealed a loose connective tissue layer at the IST-RCa interface, a finding not observed at the SST-RCa interface. The biomechanical study showed that the rigidity of the SST-RCa interface (72.10–2 N/mm) was 4.5 times higher than for the IST-RCa interface (16.10–2 N/mm) and the average maximum forces reached were 19.0 N and 10.6 N for the SST-RCa and IST- RCa interfaces, respectively. Conclusion: The IST-RCa interface consists of a loose connective tissue layer contrary to the SST-RCa interface. In parallel, two different groups in terms of the mechanical response were identified: the IST-RCa interface group had less rigidity and ruptured more quickly than the SST-RCa interface, therefore emerging as the most vulnerable interface and explaining a potential extension of rotator cuff tears. [ABSTRACT FROM AUTHOR]

The effects of steel, polyvinyl alcohol, polypropylene and glass fibre reinforcements on alkali-activated concrete (AAC) were investigated by conducting various mechanical strength tests. The fibre dosage was 0.1–0.3% by volume of AAC. Furthermore, the effects of acidic exposure on the strength of fibre-reinforced alkali-activated concretes (FRAACs) were examined by immersing samples in 10% v/v solutions of hydrogen chloride, sulfuric acid or nitric acid for 28 days. It was found that fibre additions improved the compressive and flexural strength by up to 13% and 27%, respectively, while the modulus of elasticity was significantly improved by up to 52%. Acid attack tests on AAC specimens demonstrated sulfuric acid to be highly detrimental to the mechanical and chemical properties of AACs. The strength loss in FRAAC after acidic exposure was up to 50% less than that of the plain AAC. The glass-fibre-reinforced AACs were found to be highly resistant to acid attack, whereas the steel-fibre-reinforced AACs had less resistance. These findings were further validated by scanning electron microscopy, X-ray diffraction and Fourier-transform infrared spectroscopy, which showed the changes in the microstructure of the specimens subjected to acidic environments. Overall, the fibre reinforcements improved the mechanical and durability properties of AACs. [ABSTRACT FROM AUTHOR]

Recent research is based on biocompatible drug delivery systems due to the need for bioavailability, route of administration, dose dumping, and first-pass metabolism. Despite its excellent mechanical strength, elasticity, and stability, polyurethane has associated risk factors such as high hydrophobic nature and long-term degradability. This review focuses on providing insight into polyurethane as a drug delivery system. The key objective of the review is to signify the importance of polyurethane in biomedical, the essential compounds to synthesize polyurethane, and the types of polyurethane. The review has highlighted polyurethane's drug loading and release capacity and its composites in various forms. The essential biological studies such as polyurethane's antibacterial, antiinflammatory, and anticancer activity were also discussed. Herein, polyurethane and its hybrid composites can be a potential material for future implantable drug delivery systems. [ABSTRACT FROM AUTHOR]

Since the discovery of lasers, high-quality nonlinear optical (NLO) single crystals have served as the foundation for the creation of novel, cutting-edge devices that meet societal demands. Modern optoelectronic applications such as telecommunication lasers, optical fibers, photodiodes, solar cells, etc. favor high-performance nonlinear optical single crystals with improved optical nonlinearity. Organic crystals are extensively explored for these applications because of their high NLO coefficient. This paper deals with the problems and advancements of organic nonlinear optical single crystals. Here, we review the growth and characterizations of various tosylate family crystals from the vast realm of organic single crystals and their potential applications in the field of optoelectronic devices. Various properties like linear and nonlinear optical, thermal, mechanical, and laser damage threshold values for these samples have been summarized. The attempts are made for highlighting how these tosylate (p-Toluenesulfonic acid based) family crystals can be realized into efficient optoelectronic devices by summarizing variously reported cut-off wavelengths and their wide transmission ranges. [ABSTRACT FROM AUTHOR]

Swelling-shrinkage deformation of expansive soils is the primary governing factor for development of the crack network, which is intimately associated with the bearing capacity and the structural integrity of the soil body. To suppress the swelling-shrinkage characteristic, sintered red mud was utilized as a curing agent to stabilized expansive soil, and the physical property testing phase consisted of compaction tests, Atterberg limit tests and pH tests to derive patterns on the physical and mechanical properties of the expansive soil influenced by the incorporation of red mud. The principal engineering property tests include unconfined compressive tests, one-dimensional swell tests, desiccation-induced crack study and micro-structure analysis by scanning microscopy techniques. The test findings demonstrate that even red mud would somewhat weaken the strength, but restrict the plasticity and successfully prevent swelling-shrinkage deformation of expansive soils. Such an effect is positively correlated with the red mud content. When the content reaches 20%, the crack ratio reduction exceeds 40%, the swelling deformation are reduced by about 20%, and the unconfined compressive strength higher than 500 kPa with dry density of 1.6 g/cm3. The stabilization of expansive soils with red mud effectively increases the structural integrity of the soil layers and the safety of constructions to offer guidance for environmentally friendly construction in expansive soil areas. [ABSTRACT FROM AUTHOR]

In the past two decades several studies have been reported on thermoplastic-based 3D printed sensors. However, little has been reported on wearable sensors prepared by thermoplastic printing on woven fabric, especially for four-dimensional (4D) properties. This study reports the 3D printing of thermoplastic polyurethane (TPU) on woven fabric by using a fused filament fabrication (FFF) setup for the fabrication of wearable sensors. Further, rheological, mechanical, voltage resistance (V-R), radio frequency (RF), and 4D capabilities of the 3D printed substrate have been established. The 3D printing of TPU on woven fabric was performed at 225°C nozzle temperature with a printing speed of 21 mm/s, and infill density was kept at 80% and 100%. The RF characteristics were calculated using a vector network analyser (VNA) which suggests that there is no shift in resonating frequency (2.60 GHz at −81 dB) for ring resonator printed with 100% infill density (with an increase in strain value), whereas for 80% infill density sensor there was a notable shift in resonating frequency (from 2.82 GHz at −75 dB to 2.71 GHz at −76 dB) when the sensor was strained under load which further lead to a change in dielectric constant (${\varepsilon _r}$ ε r ) and loss tangent ($\tan \delta $ tan δ). [ABSTRACT FROM AUTHOR]

Himalayan nettle fibre is abundantly available in the Himalayan regions of India and can effectively replace synthetic fibre in epoxy-based polymer composite synthesis. Fibre from nettle plants can be extracted by water, dew, controlled microbial retting, enzymatic treatment, and mechanical decortication methods. Cellulose (>86 wt.%) is the principal constituent of this fibre. In this study, epoxy-based composites were prepared with 0, 15, 20, 23, 25, 27, and 30 wt.% fibre loadings and investigated the influence of fibre content on thermal, mechanical, and physical properties. The samples were analysed with X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, universal testing machine, dynamic mechanical analysis, thermogravimetric analysis, density and void fraction measurement, and water absorption test. It was found that mechanical and thermal properties were increased with the increase in fibre loadings, attaining the maximum values at 23 wt.%, which signified the improvement in mechanical and thermal properties with fibre reinforcement. The fibre fraction of 23 wt.% resulted in the higher tensile (57.69 MPa), flexural (98.60 MPa), impact (0.689 J) strength, better thermal stability, higher storage modulus (1390.90 MPa), loss modulus (413.05 MPa), and crystallinity (40.5%). This study concludes 23 wt.% fibre loading as optimum reinforcement for the studied epoxy polymer. [ABSTRACT FROM AUTHOR]

Bioceramics composed of calcium and magnesium silicates have garnered increasing attention for the development of porous scaffolds in bone tissue engineering (BTE). This heightened interest is primarily attributed to their remarkable bioactivity and their capacity to form strong bonds with hard tissue. Fabricating nanocomposite scaffolds is a recognized approach for improving the characteristics of scaffolds used in BTE. This research investigates the mechanical and biological properties, antibacterial activity, and drug-release characteristics of scaffolds composed of akermanite (AKT), monticellite (MON), and monticellite-akermanite (MON-AKT). These scaffolds were fabricated utilizing the space holder process. Additionally, the in vitro drug release profile and antimicrobial activity of Azithromycin (AZT)-loaded MON-AKT composite scaffolds were investigated. The findings showed that the Mon-15 wt% AKT nanocomposite scaffold had the highest density, the smallest grain and micropore sizes, and the lowest porosity. In contrast, integrating AKT into MON-based composite scaffolds resulted in materials characterized by high mechanical strength and stability within physiological environments. The MON-AKT nanocomposite scaffolds exhibited cytocompatibility and demonstrated a high level of alkaline phosphatase (ALP) activity in osteogenic studies. Furthermore, antimicrobial activity assessments revealed that the AZT-encapsulated MON-AKT composite scaffolds effectively inhibited the growth of both S. aureus and E. coli bacteria. The outcomes showed that the antibacterial efficacy of the scaffold depends on both the amount of AZT and the type of bacteria. Overall, MON-AKT/3AZT scaffolds exhibited significantly superior bacterial inhibition compared to other scaffolds, making it a promising option for treating bone tissue defects. [ABSTRACT FROM AUTHOR]

[Display omitted] Low mechanical strength is still the key question for collagen hydrogel consisting of nanofibrils as hard tissue repair scaffolds with no loss of biological function. In this work, novel collagen nanofibrous hydrogels with high mechanical strength were fabricated based on the pre-protection of trisodium citrate masked Zr(SO 4) 2 solution for collagen self-assembling nanofibrils and then further coordination with Zr(SO 4) 2 solution. The mature collagen nanofibrils with d -period were observed in Zr(IV) mediated collagen hydrogels by AFM when the Zr(IV) concentration was ≥ 10 mmol/L, and the distribution of zirconium element was uniform. Due to the coordination of Zr(IV) with ─COOH, ─NH 2 and ─OH within collagen and the tighter entanglement of collagen nanofibrils, the elastic modulus and compressive strength of Zr(IV) mediated collagen nanofibrous hydrogel were 208.3 and 1103.0 kPa, which were approximate 77 and 12 times larger than those of pure collagen hydrogel, respectively. Moreover, the environmental stability such as thermostability, swelling ability and biodegradability got outstanding improvements and could be regulated by Zr(IV) concentration. Most importantly, the resultant hydrogel showed excellent biocompatibility and even accelerated cell proliferation. [ABSTRACT FROM AUTHOR]

Poly(butylene adipate‐co‐terephthalate) (PBAT) is popular because of its low cost, biodegradability, good processing properties, flexibility, and mechanical features. In this study, we explore the potential of PBAT‐based bioplastics by adding AgVO3 nanorods with PBAT to reduce costs. We produced nanocomposite films of PBAT reinforced with 1, 3, and 5 wt% of AgVO3 nanorods using solvent casting. The inclusion of AgVO3 in the structure of PBAT was investigated through Fourier transform infrared spectroscopy, x‐ray diffraction, and scanning electron microscopy. The nanocomposite films demonstrate excellent properties, surpassing those of single‐component blends, enhancing mechanical properties, and improving the barrier properties of nanocomposite films. The water vapor transmission rate of AgVO3 reinforced (5 wt%) nanocomposite films improved by 42.45% compared to pure PBAT films. The tensile strength of the PBA‐3 film was 37.19 MPa, exhibiting higher strength than the films produced from clean PBAT (19.73 MPa). The AgVO3‐reinforced films demonstrated increased resistance to moisture and water, as indicated by their higher water contact angle values (88.04°). Food‐borne bacteria like Staphylococcus aureus and Escherichia coli have been stable to the antibacterial activity of the nanocomposites on the addition of AgVO3.The potential applications of these nanocomposite films in food packaging are promising, offering a sustainable and effective solution to food preservation. Highlights: The AgVO3‐filled poly(butylene adipate‐co‐terephthalate) (PBAT) nanocomposite films exhibit superior mechanical, barrier, and resistance to moisture and water compared to neat PBAT films.The water vapor transmission rate of the film is significantly enhanced, with a 42.45% enhancement in films reinforced with 5 wt% AgVO3.AgVO3‐filled PBAT nanocomposites demonstrate effective antibacterial activity against Escherichia coli and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Hierarchically porous silicon carbide (SiC) is an important catalyst support widely used in various gas and liquid catalytic processes. Conventional approaches to fabricate such SiC have limited design flexibility and separated catalyst‐loading step is necessitated. Herein, a one‐step, direct vat‐photopolymerization 3D printing of hierarchically porous SiC loaded with Co/Ni based catalyst is demonstrated with Pickering emulsion as feedstock for the first time. Compared with normal ceramic slurries, Pickering emulsion dramatically increases the cure depth (by 50%) and emulsion stability, which allow continuous printing of complex SiC structures with uniform pore morphology. The resultant hierarchical porous SiC offered ≈40% better mechanical strength as compared with non‐hierarchical counterpart. By dissolving metal salts into aqueous phase in Pickering emulsions, complex architected structures with Co or Ni/Co in situ loaded in SiC matrix are printed. The metal salts are then thermally converted into oxides or silicates as catalysts anchored on SiC, exhibiting excellent catalytic activity and reusability. The emulsion templating strategy holds great facility to load various highly attractive materials such as high entropy oxides or functional fillers whilst reaping the benefits of vat photopolymerization for a myriad of applications in catalysis, batteries, and structural supports. [ABSTRACT FROM AUTHOR]

The paper presents the investigation on the influence of humidity, heat treatment temperature, the grain size distribution of periclase, aging time prior to heat treatment, and the amount of carbon in the charge on the strength properties of periclase-carbon samples. It is established that the moistening prior to heat treatment and aging duration have no influence on the mechanical strength of the materials. The mechanical strength of the samples increases with the increase in the concentration of finer particles of periclase in the charge. Given that the variation in carbon content (ranging from 3 to 11%) has no significant impact on the mechanical strength of the samples, it is recommended that the carbon content (in the form of graphite) in the charge mixture be determined on a case-by-case basis, in line with the intended use of the periclase-carbon products. In the investigated temperature range (125 – 250°C), the highest mechanical strength of the samples was observed at a heat treatment temperature of 200°C. [ABSTRACT FROM AUTHOR]

The effect of silica (SiO 2) addition (0 wt%-20 wt%) on the microstructural and mechanical properties, as well as the in vitro response of calcium phosphate scaffolds for potential application in bone tissue engineering (BTE) was investigated in this research. Scaffolds characterized by high porosity (77%–88 %) and interconnected spherical pores with a broad range of pore sizes (5–600 μm) were fabricated using in-situ foaming method. Incorporated silica affected the phase transformation of hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) and led to the development of new crystalline silica-rich phases like silicocarnotite and wollastonite. The reinforcement of silica became apparent during the tests of mechanical properties. Scaffolds with 5 wt% of SiO 2 exhibited compressive strength (1.13 MPa) higher than pure HA scaffolds (0.93 MPa). Bone bonding potential of the materials was tested in simulated body fluid (SBF), demonstrating this potential in silica-doped samples. Additionally, degradation experiments showed gradual material degradation, making it suitable for BTE applications. Furthermore, cell culture studies using human mesenchymal stromal cells (MSC) confirmed the scaffold's non-toxicity and provided insights into how the silica content influences cell viability, morphology, and osteogenic potential. The findings of this study offer valuable insights into the design and development of advanced scaffolds with tailored properties for effective BTE applications. [Display omitted] • In vitro evaluation of bioactive potential of multiphase porous ceramic materials for non-loadbearing bone regeneration. • In-situ foaming technique was used to produce porous bioceramic. • Si-containing phases undergo selective degradation under conditions that simulate osteoclastic activity. • Si-containing phases release Si into test media during degradation tests – possible osteoblastogenetic response in vivo. [ABSTRACT FROM AUTHOR]

At elevated operating temperatures, a large temperature gradient can cause irreparable damage to the solid oxide fuel cells (SOFCs) stack, eventually interrupting the durability of the stack. Metal substrate support could be used to overcome this challenge. However, the application of metal substrate support poses various challenges such as different thermal expansion coefficients, pore diameters, and complex fabrication techniques. Therefore, a first-ever novel and mechanically strong ferritic stainless-steel metal mesh-supported SOFC design is developed to mitigate these challenges. The metal mesh of 200 μm thickness is laminated with tape-casted green films of anode-support, anode functional layer (AFL), and electrolyte films of SOFC. The iso-static pressure of 300 MPa exhibits a firm attachment of the green films of SOFC with the metal mesh. Subsequently, the metal mesh-supported planar SOFC exhibits 3.3 times higher flexural strength compared to the conventional commercial anode-supported planar SOFC. The nano-CuO is added to constituent layers as a sintering aid to attain the maximum density at a lower sintering temperature of 1100 °C. The result shows that the practical application of the metal mesh-supported cell technology has a great potential to overwhelm the mechanical durability of SOFCs. [ABSTRACT FROM AUTHOR]

In this work, a bio-based resin of acrylated epoxidized soybean oil (AESO) mixed with three types of active diluents (Isoborneol methacrylates [IBOMA], tripropylene glycol diacrylate [TPGDA], and Ethoxylated trimethylolpropane triacrylate [ETPTA]) is used to form a protective UV-curable coating film on calcium alginate water-carrying microspheres (CA-WCMs). Calcium alginate microspheres (CAMs) have previously been used to encapsulate only ester soluble or oil-in-water core materials, thus limiting their application. After UV-curing with an increased active diluent dose, the pencil hardness, pendulum hardness, and mechanical strength of the CAMs increased. A photopolymerization kinetics study reveals that the maximum double bond (C=C) conversion rates of AESO-IBOMA, AESO-TPGDA, and AESO-ETPTA are 95, 92, and 86%, respectively, and the maximum conversion rate of C=C bond is 87% in their mixed system. Additionally, the water retention rate of the water-carrying microspheres (WCMs) increased with an increasing number of coating layers, plateauing after the number of layers exceeded four. The water retention is favorable, with more than 75% of the water stored for a duration of 50 days. Overall, the cost-effective and environmentally friendly method has shown encouraging results in the acquisition of water-absorbing CAMs, with the potential to overcome existing implementation constraints. [ABSTRACT FROM AUTHOR]

Quetiapine (QTP) is a moderately water-soluble biopharmaceutical classification system (BCS) class II antipsychotic drug used to treat schizophrenia. Carboxymethyl chitosan (CMC) microspheres were prepared using a co-precipitation approach. The Quetiapine was translocated to the brain through a nasal route using carboxymethyl chitosan-calcium carbonate (CMC-CaCO3) hybrid microspheres. During this process, optimization controlled the size of the microspheres by controlling the volume of solution, precipitating agent, and concentration ratios of the precursors. The optimized batch showed a narrow size distribution with high stability in the dispersed phase as characterized by dynamic light scattering. Preliminary characterization revealed crosslinking formation between the carboxymethyl groups of chitosan and the CaCO3 may be responsible for the spherical structure. The preliminary evaluations were done with Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), and UV visible spectroscopy (UV-Vis). The surface morphology was assessed by scanning electron microscopy that showed the microscale range of the spherical-shaped particles. The ex-vivo mucoadhesive studies suggested a high binding affinity toward mucin, having a sustained release effect for up to 8 h. [ABSTRACT FROM AUTHOR]

Cracks induced by internal stresses compromise the structural integrity of ceramic laminates. Such stresses can be classified into thermal stress derived from thermal expansion mismatch and shrinkage stress derived from shrinkage mismatch. Analytical models have been proposed for the former, whereas only numerical predictions have been explored for the latter. In this study, an equation is constructed to predict the shrinkage stress by modifying an elastic solution proposed in previous studies. We fabricated laminates with three‐layer sandwiched structures using only alumina specimens with high and low densities to control the shrinkage and avoid thermal mismatch. Surface cracks were initiated when the shrinkage stress exceeded the flexural strength of the surface layer. Although the original strength of the surface layer was 308.8 MPa, the laminates' flexural strength was lower than that because of shrinkage constraint. Our results demonstrate that the shrinkage stress was successfully estimated analytically using a few material properties measured in an ordinary environment. This study will ensure the structural integrity of ceramic laminates in laminate designs. [ABSTRACT FROM AUTHOR]

In recent years, various aspects of research related to pervious concrete (PC) have progressed rapidly, and it is necessary to summarise and generalise the latest research results. This paper reviews and compares the raw materials of pervious concrete, examining elements such as porosity, permeability, mechanical properties, and durability. According to comparisons, we put forward an ideal aggregate model with Uneven Surface, which may reinforce the mechanical properties. By summarising the important issues of aggregate, particle size, water–cement ratio, additives and admixtures, mixing ratio design, mixing and moulding, and other factors that affect porosity, new design methods are proposed. A new effective stress model of pervious concrete based on continuous porosity and Terzaghi effective stress is developed which may fit the effective stress principle better. Finally, by summarising the research frontiers of pervious concrete, key issues that need to be addressed in future scientific research on pervious concrete are raised. [ABSTRACT FROM AUTHOR]

An ultrafine-grained Al71Ni14.5Co14.5/CNT poly-quasicrystal (QC/CNT) composite was synthesized using spark plasma sintering of powder components developed through electroless Ni-P/CNT plating of Co particles and mechanical alloying. The performance of the synthesized samples was studied using various testing methods, such as room temperature/hot compression, wear, and corrosion tests. The results were compared to the properties of alloy samples fabricated from raw and coated powders (without CNTs). The wear rate and friction coefficient of the quasicrystalline samples improved significantly due to the contribution of the CNTs. The wear rate of the CNT-containing specimens was 0.992 × 10−4 mm3/N/m, which is 47.1% lower than that of the QC sample. The positive impact of the CNTs on the corrosion potential and current density was further validated by the potentiodynamic polarization tests in a saline solution. However, these improvements in surface properties came at the cost of a 21.5% reduction in compressive strength, although the compressive strength still remained above 1.1 GPa at 600 °C. The results highlight an interesting trade-off between surface properties and mechanical strength, pointing toward the development of materials suitable for extreme conditions. [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes (SPEs) show great promise for high-energy and high-safety lithium metal batteries. However, current SPEs suffer from low ionic conductivity and poor mechanical strength. Herein, the g-C3N4@COF heterojunction filler is constructed for SPEs for fast Li+ transport and high Li+ transference number. In addition, a robust 3D network is fabricated by using g-C3N4@COF heterojunction filler in order to further improve the mechanical robustness and electrochemical stability. As a consequence, the g-C3N4@COF-3D network/polymer electrolyte displays an ionic conductivity of 1.25×10−4 S cm−1 at 30 ℃, an electrochemical window of 5.0 V and the tensile strength of 8.613 MPa. Furthermore, the assembled LiFePO4//Li battery with the g-C3N4@COF-3D network/polymer electrolyte presents remarkable cycling stability with a capacity retention of 99.71% after 600 cycles. The above results indicate the great potential of the g-C3N4@COF-3D network/polymer electrolyte for advanced energy storage devices. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the wide application of epoxy resins in adhesives, electronic packaging materials, and aerospace fields, it is necessary to prepare high‐performance flame‐retardant epoxy resins to reduce the fire risk caused by their flammability. In this study, the rigid structure intermediate Schiff base (DMDA‐SH) was synthesized by condensation reaction of syringaldehyde (SH) with O‐Tolidine (DMDA). Then, DMDA‐SH‐DOPO, a novel P/N‐structured biobased flame‐retardant curing agent, was synthesized by addition reaction with 9,10‐dihydro‐9‐oxaza‐10‐phosphame‐10‐oxide (DOPO) and was applied to the preparation of intrinsic flame‐retardant epoxy resin. As expected, DMDA‐SH‐DOPO has good flame‐retardant properties due to the synergistic action of N/P elements. Epoxy resin with only 2.5% DMDA‐SH‐DOPO (P = 0.16%) can pass the UL‐94 V‐0 test. Compared with DGEBA/DDM, DMDA‐SH‐DOPO‐7.5's (P = 0.49%) peak heat release rate was reduced by 48.4% and the limiting oxygen index (LOI) reached 27%, making it a flame‐retardant material. From the point of view of carbonaceous residue performance, the expansion height of carbon residue after DMDA‐SH‐DOPO‐7.5 combustion is significantly increased, and the amount of carbon residue at 800°C is increased by 36.4%. In addition, appropriate DMDA‐SH‐DOPO can effectively improve the bending property of epoxy resin. This study provides a new idea for preparing renewable high‐performance intrinsic flame‐retardant epoxy resin. [ABSTRACT FROM AUTHOR]

A novel acrylic monomer containing a nitrofuran motif, referred to as longchain nitrofuran methacrylate (LNFMA), is reported. In comparison to the previously reported nitrofuran methacrylate (NFMA), LNFMA has a longer side chain, and when incorporated into bone cement, the resulting LNFMA bone cement exhibits improved mechanical strength. At the same concentration, NFMA-5% cement has only 21.6 ± 1.3 MPa, while LNFMA-5% cement has a compressive strength of 42.64 ± 0.94 MPa. LNFMA bone cements exhibit antimicrobial activity against Staphylococcus aureus, with LNFMA-30% cement reaching 57.38% ± 5.53%. Moreover, LNFMA cement demonstrates excellent biocompatibility both in vitro and in vivo. The results showed that LNFMA monomer had optimized mechanical strength compared with previously reported NFMA monomers, and LNFMA bone cement had good antibacterial activity and biocompatibility. [ABSTRACT FROM AUTHOR]

Ceramic membranes based on SiC have a number of advantages, namely high surface hydrophilicity, good water permeability and negative surface charge, which leads to better performance during their operation, but they require high sintering temperatures due to covalent bonds. The use of sintering agents can significantly reduce the final sintering temperature. The aim of this work was to synthesise ceramic membranes based on silicon carbide and to study the effect of liquid glass on their mechanical, electrical and antibacterial properties. The physicochemical properties of SiC ceramic membranes were investigated by diffraction analysis and scanning electron microscopy. It was found that, regardless of the type of carbonate, only two phases are identified: the main phase of the initial mixture, silicon carbide and the phase added to the mixture, corundum. The obtained SiC ceramic membranes are macroporous, as indicated by the transport properties (9.03–18.66 cm3/(min-cm2)) and the results of electron microscopy (13–20 μm). SiC ceramic membranes obtained are characterised by high strength (16.3–46.8 MPa). Studies of antibacterial properties have shown that SiC-based ceramic membranes do not exhibit antibacterial properties, but modification of ceramic membranes with titanium oxide inhibits the growth of gram-negative bacteria. The results of this study are useful for enriching the knowledge about the production of silicon carbide membranes and are aimed at further research and development of selective membranes (micro- and ultrafiltration) based on them. [ABSTRACT FROM AUTHOR]

In this study, the bulk modification method via incorporating two different types of waterproof admixtures was adopted to make natural hydraulic lime-based mortars more durable. The influence of two admixtures and their dosages on the hydration, physical, mechanical, and aggressive environment resistance properties were evaluated. The correlations between pore and water absorption characteristics, between hydration, pore characteristics, and mechanical strength were interpreted. Results showed that two waterproof admixtures changed the microscopic reaction between different components as well as internal structure of NHL-based mortar. Introduction of silane impregnant improved the workability of natural hydraulic lime-based mortars, and the appropriate dosage of silane impregnant facilitated hydration and improved mechanical strength at 28 and 90 days. Silane impregnant modified mortars were no more hydrophilic, acid resistance was improved while water absorption characteristics were not obviously improved even resulting in degraded freeze-thaw cycle resistance. Introduction of silicon-acrylic latex deteriorated the workability and retarded hydration of natural hydraulic lime-based mortars, regardless of dosage, leading to the degradation of mechanical strength. However, water absorption characteristics and freeze-thaw cycle and acid resistance can get a noticeable improvement when appropriate dosage was adopted. [ABSTRACT FROM AUTHOR]

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Herein, we report a micro-tubular protonic ceramic fuel cell with novel bio-inspired four-channel structure, which has a considerable maximum output power density of 231 mW cm−2 and good long-term stability. [ABSTRACT FROM AUTHOR]

The current study aims to introduce a new polymeric composite consisting of epoxy resin as the matrix and gadolinium oxide (Gd2O3) as the neutron adsorption ingredient. The shielding performance of the composite was assessed by neutron attenuation experiments with an Am-Be source and polyethylene moderator. The results of these experiments showed an appreciable agreement with the Monte Carlo simulations. Other characteristics of the composite, including mechanical strength, thermal stability, microtexture, and its chemical compositions, were examined using standard tensile test, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, static light scattering analyses, and Fourier-transform infrared spectroscopy (FTIR). The results indicated that the new composites offer appreciable neutron absorption properties so that samples with 0.5%, 2%, 5%, and 10% Gd2O3 content could reduce the neutron beam intensity by 54%, 63%, 66%, and 70% at a thickness of 4 cm. [ABSTRACT FROM AUTHOR]

As demand for sustainable building materials rises, the use of waste rubber in civil engineering is gaining attention. This study proposes a method to modify waste rubber using polyvinyl alcohol (PVA) to enhance its material properties and expand its applications. A dataset was created focusing on the mechanical strength of cementitious materials incorporating PVA-modified waste rubber, and multiple machine learning methods were used to develop regression prediction models, particularly evaluating the support vector regression (SVR) model. Results show that the SVR model outperforms others, achieving mean squared errors of 1.21 and 0.33, and mean absolute errors of 2.06 and 0.15. Analysis indicates a negative correlation between waste rubber content and the water-to-cohesive ratio (w/c) with strength indexes, while a positive correlation exists between curing age and PVA. Notably, waste rubber content significantly affects strength. The mechanical strength of cementitious materials was notably enhanced by PVA-modified waste rubber, likely due to PVA's dispersion and bridging effects. This study presents a novel approach to sustainably recycle waste rubber, highlighting its potential in construction materials. [ABSTRACT FROM AUTHOR]

Recycled concrete incorporating additional super-absorbent polymer (SAP) and machine-made stone powder (MSP) was prepared using a two-factor, four-level orthogonal test. To enhance the frost resistance of recycled concrete and improve its mechanical properties, such as compressive and flexural strength, the prepared concrete underwent 200 freeze–thaw cycles. Before freeze–thaw cycles, the amount of SAP has a predominant influence on the mechanical properties of recycled concrete in comparison with MSP. After 200 cycles of freeze–thaw, the influence of MSP became more significant than that of SAP. Typically, the compressive strength and flexural strength exhibited a trend of initially increasing and then decreasing as the contents of SAP and MSP increased. The optimized recycled concrete was identified as S16M6, containing 0.16% SAP and 6% MSP, as demonstrated by the minimal strength loss after freeze–thaw cycles. This study also proposed a linear regression model for predicting the mechanical properties which offered valuable guidance for the engineering application of recycled concrete mixed with SAP under the freeze–thaw cycle environment. [ABSTRACT FROM AUTHOR]

Background: Bone grafts are extensively used for repairing bone defects and voids in orthopedics and dentistry. Moldable bone grafts offer a promising solution for treating irregular bone defects, which are often difficult to fill with traditional rigid grafts. However, practical applications have been limited by insufficient mechanical strength and rapid degradation. Methods: This study developed a ceramic composite bone graft composed of calcium sulfate (CS), β-tricalcium phosphate (β-TCP) with/without graphene oxide (GO) nano-particles. The biomechanical properties, degradation rate, and in-vitro cellular responses were investigated. In addition, the graft was implanted in-vivo in a critical-sized calvarial defect model. Results: The results showed that the compressive strength significantly improved by 135% and the degradation rate slowed by 25.5% in comparison to the control model. The addition of GO nanoparticles also improved cell compatibility and promoted osteogenic differentiation in the in-vitro cell culture study and was found to be effective at promoting bone repair in the in-vivo animal model. Conclusions: The mixed ceramic composites presented in this study can be considered as a promising alternative for bone graft applications. [ABSTRACT FROM AUTHOR]

Natural fiber has recently been developed as a reinforcing material for a wide variety of applications in reinforced plastics. It is preferred as a reinforcement material in the production of polymer matrix composites due to its biodegradability, low cost, relatively low density, environmental friendliness, and moderate mechanical properties. In this experiment, compression-molded composites were created using coir fiber (CF) and banana fiber (BF) as reinforcement and poly vinyl ester (PVE) as matrix. Eight different composite compositions (S1 to S8) were prepared, with the weight percentage of CF and BF adjusted to 0 (neat polymer), 7.5, 12.5, 17.5, 22.5, 27.5, and 35%. Tensile tests, flexural tests, and impact tests were conducted to determine the mechanical strength of the material. The samples were created following the appropriate ASTM mechanical testing standards and then tested accordingly. The water absorption test employed three different types of water-normal water, sea water, and distilled water. The thermal characteristics of the hybrid biocomposites were also examined using thermogravimetric analysis (TGA). Among the eight samples, sample S6 (Banana 22.5% & Coir 12.5%) exhibited the highest mechanical and thermal strength when compared to the other seven samples. [ABSTRACT FROM AUTHOR]

In this study, the effect of curing temperature on mechanical strength and thermal properties of hydraulic limestone powder (LS) concrete is investigated. The hydration products and microstructure of hydraulic LS concrete are characterized through X-ray diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP). The results indicate that the mechanical strength decreases with an increase in the LS dosage. The largest mechanical strength at 3 and 7 d is recorded at the curing temperature of 50 °C, that at 28 and 90 d is obtained at 20 °C, whereas the lowest mechanical strength from 3 to 90 d is obtained at 5 °C. The thermal conductivity and thermal diffusivity of LS concrete are positively correlated with the compressive strength. The adiabatic temperature rise decreases with an increase in the LS dosage, and the largest temperature rise is obtained at the initial temperature of 5 °C, followed by those obtained at 20 and 50 °C. The longest fibrous C-S-H and thickest plate Ca(OH)2 with the largest size at 90 d is obtained at a curing temperature of 50 °C, followed by those obtained at 20 and 5 °C. The MIP results indicate that the largest total amount of gel pores and medium capillary pores at 90 d are obtained at a curing temperature of 20 °C, followed by 50 and 5 °C. [ABSTRACT FROM AUTHOR]

The shallow working face of the hidden coal field is affected by the wind-oxidized zone of the bedrock of the roof, and under the influence of wind-oxidization, the engineering geological conditions of the rock body deteriorate, which has a greater impact on the management of the roof of the working face and the prevention and control of water hazards. The engineering geological characteristics of wind-oxidized zone were studied in the working face of 1410 (3 ) near loose layer in Zhangji coal mine, Huainan mining area, Anhui Province, as an example. Based on the drilling project of the underground roof of the working face, cores were taken within 30 m of the roof of the working face, and on the basis of which, the mineral composition analysis of the wind-oxidized zone rocks was carried out by X-ray diffraction (XRD) . The physical and mechanical property tests of fresh and wind-oxidized rocks were carried out by indoor physical and mechanical tests, and the depth and degree of development of the wind-oxidized zone on the top of the working face were evaluated based on the rock mechanical properties and macro-geological characteristics of the core. The results show that the mineral composition of bedrock wind-oxidized zone is dominated by kaolinite, montmorillonite, illite and other clay minerals, which are easy to expand in contact with water, and are beneficial to inhibit the development of water-conducting crack zones in the roof slab. Under the influence of wind-oxidized action, the porosity of the rock increases by about 15%, and the uniaxial compressive strength is reduced by about 50%, which makes the deterioration of the engineering geological conditions of the mudstone more obvious than that of the sandstone. The depth of the wind-oxidized zone of bedrock in the working face is about 16 ~ 20 m, and the wind-oxidized degree is divided into grades. The degree of rock wind oxidation is mainly manifested as strong weathering-complete weathering. The research results provide the basis and reference for the selection of support type and roof management of the working face, and provide reference for the exploration of wind-oxidized zone and evaluation of engineering geological conditions of the working face under similar conditions. [ABSTRACT FROM AUTHOR]

Based on the ultrasonic welding technology, this study uses three different welding widths to weld copper cables with different specifications. The influence of welding width on the mechanical properties and microstructure of each group of welded joints was systematically studied for the first time. The thermal shock test was carried out for each group of welded joints under optimum welding width to simulate the influence of severe temperature change environment on joint performance. It is found that the cross-sectional area of joint is 20 mm2 and optimal welding width of joint composed of two and three cables is 7 mm. The optimal welding temperature of the joint composed of four cables is 5 mm. Under the optimal welding width, the average shear strength of two-cable joint reaches 309.4 N. The four-cable joint is only 232.2 N. Moreover, the welding strength weakens significantly as the number of cables and the peak temperature decreases. The high temperature of bonding interface is the key factor to form a good weld. The peak temperature during welding is negatively correlated with the porosity of joint and positively correlated with peeling strength of joint. In addition, the morphology of ultrasonically welded joints has changed obviously after thermal shock test. With the participation of oxygen, the surface of welded joint is gray and bright brass, while the interior of joint is purple due to lack of oxygen. Moreover, the phenomenon of atomic diffusion and thermal expansion generates joints which were initially in a mechanically interlocked form and welding interface of the metallurgical bond under the action of high temperature. So the maximum joint peel strength is slightly improved. [ABSTRACT FROM AUTHOR]

Mechanical qualities play a critical role in increasing the industrial applications of carbon-carbon composite materials as their porosity determines the strength of the material. In this study, carbon blocks with improved packing properties were produced by controlling various particle size distributions of coke particles. Particle-size diversity and geometric packing structure favorably affected the packing properties of the powder. Coke samples with tap densities up to 1.258 g/mL were prepared by controlling the size distribution of the coke particles. The porosity of the carbon block was calculated using three density definitions. The closed pores were reduced by up to 13.68% through the packing density of the particles, and the open pores were controlled by the coke/pitch mixing conditions regardless of the tap density. The carbon block showed a total porosity of 21.61% and a maximum compressive strength of 131 MPa by controlling the tap density of the coke. The proposed technique will be useful in various industries that require appropriate tap density control and will improve the compressive strength of composite materials. [ABSTRACT FROM AUTHOR]

The utilization of biofiber in recent years has significantly increased due to its advantages like being environmentally friendly, availability, and low costs. This paper investigates the physicochemical, mechanical, and morphological properties of the yucca fiber extracted by three methods such as water‐retting, traditional, and chemical methods. These analyses are designed to evaluate the extraction methodology and the hypothesis of the influence of harvesting location and growth conditions of the fiber. Various technologies are used, such as SEM, FTIR, XRD, and tensile tests. The fiber extracted by water retting is the strongest in the mechanical analysis with a strength of 690.48 MPa, followed by fiber extracted with the traditional method with 685.48 MPa, also 673.06, 657.94, 373.68 MPa for the fiber extracted by the chemical method using 3%, 5%, 10%NaOH respectively. The fiber obtained by the water retting method also has a higher chemical composition with 80.25% cellulose, 10.45% lignin, and 13.75% hemicellulose. The morphological characteristics are examined using Scanning Electron Microscopy. The crystallinity index ranged from 61.75% to 70.77%, and crystallite size from 1.73 to 2.04 nm is calculated from the XRD analysis. All these results confirm that yucca fiber can be a good sustainable choice for composite reinforcement. [ABSTRACT FROM AUTHOR]

Highlights This study aimed to evaluate the effect of incorporating Mahua oil cake microcellulose (MOCM) on the mechanical and sound absorption properties of flax fiber‐reinforced polymer composites fabricated using the compression molding technique. X‐ray diffraction (XRD) analysis revealed that MOCM had a crystallite size (Cs) of 6.71 nm and a crystallinity index (CI) of 63.25%, indicating its potential for mechanical reinforcement. Thermogravimetric analysis (TGA) demonstrated that MOCM exhibits thermal stability up to 355.44°C, which is suitable for high‐temperature applications. Mechanical testing revealed that the incorporating 7.5 wt.% MOCM into flax fiber composites achieved optimal results, with the tensile strength reaching 70.23 MPa, flexural strength peaking at 113.23 MPa, and impact strength at 33.4 kJ/m2. Scanning electron microscopy (SEM) analysis confirmed the improved interfacial bonding between the fibers and matrix, contributing to enhanced mechanical performance. The noise reduction coefficient (NRC) and sound absorption coefficient (SAC) also improved with increasing MOCM content, with the highest SAC (0.328) and NRC (0.312) values observed at 10 wt.% MOCM. These findings suggest that MOCM enhances both the mechanical and acoustic properties of flax fiber composites, making it a promising material for applications in the automotive, aerospace, and construction industries, where both structural integrity and sound absorption are critical. Novel use of MOCM as sustainable cellulose for polymer composites Synergy of MOCM and flax fibers enhances mechanical and acoustic properties 7.5% MOCM compositions optimally improves strength and sound absorption MOCM: eco‐friendly alternative to synthetic fillers in polymers Comprehensive MOCM characterization for future biomaterial applications [ABSTRACT FROM AUTHOR]

Red algae, abundant along the Moroccan coast, have fostered an agar-agar industry. However, industrial processing of red algae produces significant fibrous waste, posing environmental challenges. A new challenge is to find sustainable methods for repurposing this fibrous waste. Valorizing red-algae fibers in building materials promotes sustainable development and eco-construction. This study aims to valorize these red-algae residues as fiber reinforcements in compressed earth bricks (CEB). Various mass ratios of red-algae fibers (0.5%–3%) were incorporated into CEB. The addition of raw red-algae fibers to mixtures slightly increased the Atterberg limit values of the earth mixture. A slight adjustment in manufacturing water content was also observed with fiber addition. The incorporation of red-algae fibers did not improve the mechanical strengths of the CEB. Nevertheless, at a 1.5% addition ratio, CEB exhibited compressive and flexural strengths of 4.07 and 0.77 MPa respectively. To enhance mechanical properties, fibers were pre-saturated and subjected to alkaline and double coating treatments. Untreated and treated fibers were added to CEB at an optimal mass addition rate of 1.5%. Pre-saturated fibers showed a slight improvement of 5% in mechanical strength. However, alkali-treated and double-coated fibers offer a significant improvement of 20% in the mechanical strengths of CEB, demonstrating the efficacy of treatments. [ABSTRACT FROM AUTHOR]

The effect of dosage of recycled aggregate from construction waste on the mechanical strength of cement stabilized macadam (CSM) was investigated, the optimal dosage and proportion of recycled aggregate were proposed based on the principle of the highest strength or the maximum dosage. The growth law of mechanical strength of cement stabilized macadam recycled aggregate ( CSMRA) was investigated under the optimal dosage, a prediction model of mechanical strength of CSMRA was proposed, and the reliability of prediction was verified. The results show that the compressive strength of CSMRA increases and then decreases with the increase of recycled fine aggregate dosage, decreases with the increase of recycled coarse aggregate dosage, and the maximum dosage of recycled aggregate is 70% (mass fraction). The correlation coefficient of established mechanical strength growth equation and prediction model is more than 0. 98, and the error between predicted value and measured value is no more than 14. 0%. This indicates that the model can accurately predict the mechanical strength of CSMRA at other ages after determining cement dosage, aggregate type, mineral proportion and 7 d strength. [ABSTRACT FROM AUTHOR]

Abstract The current study aims to introduce a new polymeric composite consisting of epoxy resin as the matrix and gadolinium oxide (Gd2O3) as the neutron adsorption ingredient. The shielding performance of the composite was assessed by neutron attenuation experiments with an Am-Be source and polyethylene moderator. The results of these experiments showed an appreciable agreement with the Monte Carlo simulations. Other characteristics of the composite, including mechanical strength, thermal stability, microtexture, and its chemical compositions, were examined using standard tensile test, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, static light scattering analyses, and Fourier-transform infrared spectroscopy (FTIR). The results indicated that the new composites offer appreciable neutron absorption properties so that samples with 0.5%, 2%, 5%, and 10% Gd2O3 content could reduce the neutron beam intensity by 54%, 63%, 66%, and 70% at a thickness of 4 cm.

Abstract Based on the ultrasonic welding technology, this study uses three different welding widths to weld copper cables with different specifications. The influence of welding width on the mechanical properties and microstructure of each group of welded joints was systematically studied for the first time. The thermal shock test was carried out for each group of welded joints under optimum welding width to simulate the influence of severe temperature change environment on joint performance. It is found that the cross-sectional area of joint is 20 mm2 and optimal welding width of joint composed of two and three cables is 7 mm. The optimal welding temperature of the joint composed of four cables is 5 mm. Under the optimal welding width, the average shear strength of two-cable joint reaches 309.4 N. The four-cable joint is only 232.2 N. Moreover, the welding strength weakens significantly as the number of cables and the peak temperature decreases. The high temperature of bonding interface is the key factor to form a good weld. The peak temperature during welding is negatively correlated with the porosity of joint and positively correlated with peeling strength of joint. In addition, the morphology of ultrasonically welded joints has changed obviously after thermal shock test. With the participation of oxygen, the surface of welded joint is gray and bright brass, while the interior of joint is purple due to lack of oxygen. Moreover, the phenomenon of atomic diffusion and thermal expansion generates joints which were initially in a mechanically interlocked form and welding interface of the metallurgical bond under the action of high temperature. So the maximum joint peel strength is slightly improved.

Abstract Background Bone grafts are extensively used for repairing bone defects and voids in orthopedics and dentistry. Moldable bone grafts offer a promising solution for treating irregular bone defects, which are often difficult to fill with traditional rigid grafts. However, practical applications have been limited by insufficient mechanical strength and rapid degradation. Methods This study developed a ceramic composite bone graft composed of calcium sulfate (CS), β-tricalcium phosphate (β-TCP) with/without graphene oxide (GO) nano-particles. The biomechanical properties, degradation rate, and in-vitro cellular responses were investigated. In addition, the graft was implanted in-vivo in a critical-sized calvarial defect model. Results The results showed that the compressive strength significantly improved by 135% and the degradation rate slowed by 25.5% in comparison to the control model. The addition of GO nanoparticles also improved cell compatibility and promoted osteogenic differentiation in the in-vitro cell culture study and was found to be effective at promoting bone repair in the in-vivo animal model. Conclusions The mixed ceramic composites presented in this study can be considered as a promising alternative for bone graft applications.

This study investigates the efficacy of silane-modified zeolite powder in enhancing the early age crack resistance of concrete. Three concrete mixes were evaluated: a reference mix, a 20 % zeolite replacement mix, and a silane-modified zeolite mix. The silane-zeolite mix demonstrated significant improvements, extending the time to crack by 70 % compared to the reference mix (from 11.2 to 19.1 hours). Mechanical strength tests revealed a 58 % increase in first-crack strength for the silane-zeolite mix over the reference mix. Water absorption tests showed that the silane-zeolite mix absorbed 42 % less water than the reference mix, indicating a denser microstructure. Microscopic analyses confirmed these findings, revealing a more refined pore structure with reduced microcrack frequency and width in the silane-zeolite mix. These results highlight the potential of silane-modified zeolite in improving concrete durability and longevity.