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Due to a shortage of resources, exploring new biomass fillers has become critical for paper making. In this study, we reported an eco-friendly strategy for fabricating low-cost and efficient recycled paper with high mechanical properties using corrugated cardboard waste paper and harmless municipal sludge (HMS). First, the characteristics of HMS, including the particle size, pH, specific surface area, organic functional groups and organic component content, were analyzed. Then, the influence of the amount of HMS on the properties of the recycled paper was studied. Finally, the strengthening mechanism of biomass filling recycled paper was discussed. The results showed that HMS, a biomass filler for recycled paper preparation, exhibited excellent physical and chemical properties, with a median particle size of 6.395 μm, a surface area of 39.974 m2 g−1 and organic functional groups. The tensile index of the recycled paper with 30 % HMS was 13.10 Nm/g, which was 16.4 % greater than that of the unfilled paper and showed better thermal stability. This excellent performance could be attributed to the uniform distribution of HMS on the fiber surface, which improved the accessibility of hydrogen bond formation between fibers. Thus, this study proved that HMS was an excellent biomass filler for producing recycled paper. [ABSTRACT FROM AUTHOR]

The effect of shredded waste office paper was considered when producing one-layered particleboard. Five different mixing ratios of shredded waste office paper/wood particles were used (0/100, 25/75, 50/50, 75/25, and 100/0) and two amounts of urea formaldehyde (UF) resin (10% and 15%). The boards were tested for their physical and mechanical properties, including modulus of elasticity (MOE), bending strength (MOR), and internal bond (IB) strength, in accordance with the European Norm (EN) standards. All properties of the boards were found to be improved via increasing the resin content. The 15% UF-bonded board with 100% wood particles had the highest MOR, whereas the board containing 100% wastepaper for 15% UF had the highest MOE. However, there was no statistical difference between the board types. Although increasing wastepaper content in the board negatively affected the IB, the usage of wastepaper up to 25% was shown to be acceptable as a raw material in the production of particleboard. None of the prepared boards met the EN 312 (1999) requirements for thickness swelling. The boards made from shredded waste office paper were more suitable for dry and indoor use. [ABSTRACT FROM AUTHOR]

The pulp and paper industry generates vast quantities of paper sludge, posing significant environmental challenges due to its disposal in landfills or incineration. This study explores the potential of valorizing paper sludge by incorporating it into particleboard production. It aims to optimize sludge content and particle size to enhance board properties—a novel approach to waste management in the wood composites industry. Through systematic variation of sludge content (0–25%) and particle size (< 0.5 to > 2 mm), we assessed the mechanical and physical properties such as internal bond strength (IB), modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA), and thickness swelling (TS). The findings indicate that incorporating paper sludge at moderate levels (5–15%) with optimized particle sizes (< 1 mm) significantly improves the mechanical properties of the particleboard, including increased IB, MOR, and MOE while reducing WA and TS. Principal Component Analysis (PCA) further supported these results, revealing that higher-density boards with enhanced mechanical properties absorb less water, highlighting the interrelationship between structural integrity and moisture resistance. The PCA also identified thickness swelling as an independent factor, suggesting that while mechanical properties can be optimized, additional strategies are needed to control swelling. In conclusion, this study demonstrates that up to 15% paper sludge can be effectively used in particleboard production without compromising quality, provided particle size is carefully controlled. This approach not only offers a sustainable solution for managing paper sludge but also contributes to the development of eco-friendly composite materials, aligning with circular economy principles. [ABSTRACT FROM AUTHOR]

This study aims to comprehensively examine the influence of three distinct additives, namely carboxymethyl cellulose (CMC), hydroxypropyl methylcellulose (HPMC), and cellulose nanofibers (CNF), on the performance enhancement of corrugated base paper. For this purpose, steam‐exploded rice straw was treated with varying concentrations (2, 4, 6, 8, and 10 wt%) of CMC, HPMC and CNF. Analysis of the rice straw pre and post expansion, as well as the modified corrugated base paper, was conducted using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), tensile performance testing, and scanning electron microscopy (SEM). Results indicated that adding CMC, CNF, and HPMC to corrugated base paper significantly improved bonding between paper layers, particularly at 2 %, 6 %, and 8 % concentrations, respectively. This enhancement notably increased tensile strength and elastic modulus of the corrugated base paper. Tensile performance saw increases of 57.76 %, 59.01 %, and 60.25 %, while elastic modulus showed increments of 52.7 %, 9.4 %, and 136.69 %, respectively. These findings provide valuable insights for the preparation of corrugated base paper and highlight the potential of CMC, HPMC, and CNF in enhancing paper mechanical properties. [ABSTRACT FROM AUTHOR]

The primary aim of this research was to explore the feasibility of producing environmentally friendly composite materials by employing diverse hybrid matrices consisting of dammar natural resin, supplemented with small proportions of two synthetic resins: one epoxy and the other acrylic. A blend of paper and chicken feathers served as the reinforcing elements. The fabrication of these composite materials utilized a hand layup technique. Targeted for applications in the furniture industry or interior design, their mechanical properties were assessed through various tests. Specimens were obtained from the manufactured samples and subjected to evaluations for tensile strength, compression, flexure, vibrations, Shore hardness, and water absorption. Results indicated that irrespective of the testing method employed, the mechanical strength properties exhibited a decline with an increase in the percentage of dammar in the hybrid resins, whereas the elasticity properties demonstrated an increase with this percentage. [ABSTRACT FROM AUTHOR]

To solve the environmental pollution and harm to human health caused by the use of adhesives in traditional paperboard, the development of environmentally friendly mycelium paperboard has become a hot topic. Due to the high dipole moment and hydrogen bonding between macromolecules, hyphae can form clamp shaped connection structures for nutrient reproduction and transfer, and can grow on natural agricultural waste, forming a natural biocomposite material. This study determined the combination of Ganoderma weberianum/corn straw, and designed single factor cultivation conditions such as cultivation time, straw particle size, and fructose addition to explore the effects on the mechanical properties, waterproof properties, and thermal decomposition performance of the hyphal paperboard formed by hot pressing. The optimal cultivation process was obtained through orthogonal experiments. The experimental results indicate that various factors have varying degrees of influence on the edgewise strength, flexural stiffness, and static bending strength and waterproofness of paperboard. Firstly, when the cultivation time was 30 days, the flexural stiffness reached 16.63 mN/m, which was 21.2% higher than the flexural stiffness of kraft paper (13.10 mN/m). Moreover, with the increase of cultivation time, the water absorption (24 hours) had also decreased from 3.92% to 1.27%. Secondly, previous research results have shown that the addition of fructose, glucose, and sucrose increases the biomass growth rate of strains. In this study, fructose was chosen as an exogenous nutrient, and the results showed that when a mass fraction of 5% fructose was added, the mechanical properties were the best, with a flexural stiffness of 18.87 mN/m, which was 30.5% higher than that of kraft paper (13.10 mN/m). Thirdly, the particle size of the sbstrate has a significant impact on the appearance and properties of the material. The results show that, from the appearance perspective, the mycelium paperboard made of 0.165～0.250 mm particle size has the closest appearance and feel to kraft paper. At the same time, during the testing period, it was found that the mycelium paperboard made of 0.165～0.250 mm straw was the least prone to deformation and loosening, and the molding effect was significantly improved compared to other components. In terms of mechanical properties, the edgewise strength increased by 17.4%, the static bending strength increased by 14.9%, and the flexural stiffness increased by 57.3%. The experimental results show that the degree of influence of various factors on the edgewise strength, flexural stiffness, and static bending strength of paperboard is in the order of particle size, cultivation time,fructose addition amount. When the particle size is 0.165～0.250 mm, the cultivation time is 30 days, and the fructose addition of 5.0%, the edgewise strength of the prepared paperboard is 14.36 N/mm, the static bending strength is 10.89 MPa, and the flexural stiffness is 33.09 mN/m. As the particle size decreases, the water absorption rate and water thickness expansion rate of the paperboard after 24 hours of water absorption decrease to 0.86% and 0.59%. The mycelium paperboard prepared by different single factors has the same thermal decomposition process, starting at around 150 ℃ and reaching its maximum at 350 ℃. This study provides a reference basis for the development and application of mycelium composite materials in the future. [ABSTRACT FROM AUTHOR]

Xuan paper is one of the most famous handmade papers in China and is an important paper for conservation. However, the evenness of Xuan paper has not yet received much attention. In this study, the distribution of the in-plane grammage and mechanical properties of Xuan paper are measured. It is found that the distribution of the in-plane grammage and mechanical properties of Xuan paper is uneven. In the handmade direction, the grammage and mechanical properties of Xuan paper are overall largest in the lower area, followed by the upper and middle areas. The sheet forming process of Xuan paper has an important effect on the distribution of in-plane grammage, mechanical properties, and fiber orientation of Xuan paper. The folded state has a negative effect on the mechanical properties of the folded area of Xuan paper. This study will help raise awareness of the unevenness in physical properties of Xuan paper, which is important in both conservation and research applications. [ABSTRACT FROM AUTHOR]

The mechanical properties for paper sheets composited with glucose (Glc), methyl cellulose (MC), and carboxymethyl cellulose (CMC) were investigated. The paper composites were prepared by immersing paper sheets in aqueous solutions of these materials and drying at 100 °C for 30 min. The stress–strain curves for these paper composites were measured by a uniaxial tensile apparatus with a stretching speed of 2 mm/min. The breaking stress and strain for untreated paper were 24 MPa and 0.016, respectively. The paper composites demonstrated stress–strain curves similar to the untreated paper; however, the breaking point largely differed for these composites. The breaking strain and breaking stress for the Glc composite slightly decreased and those for the MC composite gradually increased with the concentration of materials composited. Significant increases in the mechanical properties were observed for the CMC composite. The breaking stress, breaking strain, and breaking energy for the 3 wt.% CMC composite were 2.0-, 3.9-, and 8.0-fold higher than those for untreated paper, respectively. SEM photographs indicated that the CMC penetrated into the inner part of the paper. These results strongly suggest that the mechanical improvement for CMC composites can be understood as an enhancement of the bond strength between the paper fibrils by CMC, which acts as a bonding agent. It was also revealed that the breaking strain, breaking stress, and breaking energy for the CMC composites were at maximum at the first cycle and decreased gradually as the immersion cycles increased. [ABSTRACT FROM AUTHOR]

Hemp hurd fiber, a low-value waste stream from the hemp industry, has potential downstream applications as an alternative to non-renewable plastics for single-use food service ware and packaging applications. Packaging paper substrates made from chemically pulped hemp hurd, mixed in varying ratios with bleached thermomechanical radiata pine pulp were developed and tested. Handsheets were characterized using several mechanical property tests including tensile strength, tearing resistance, burst strength, short-span compression, ring crush, together with Gurley air resistance, contact angle, and Cobb60 tests. Generally, addition of hemp hurd fibers significantly improved handsheet mechanical properties. Hot-pressing of the handsheets so as to approximate molded fiber thermoforming further enhanced their performance, with pure hemp hurd handsheets having the highest mechanical properties and barrier performance. A prototype was successfully thermoformed from hemp fiber, demonstrating overall feasibility of this fibre source for molded fibre objects. [ABSTRACT FROM AUTHOR]

In recent years, an increasing focus has been placed on the mitigation of carbon dioxide emissions, underscoring the significance of the sustainable energy-conservation industry as a prominent and consequential field of development. As an energy-intensive procedure within the papermaking sector, the process of pulp-fiber beating necessitates an imperative exploration of alternative approaches aimed at mitigating energy consumption. This study has synthesized renewable cationic cellulose nanoparticles (CCNPs) extracted from the parenchymal cells of maize stalk pith. The objective is to demonstrate their viability as a reinforcing additive for paper sheets, thereby reducing the reliance on conventional beating processes. The results showed that CCNPs were prone to augment the physical strength of bleached papers, compared with unbleached papers. The inclusion of 9% CCNPs led to a remarkable 163.5% and 140.0% increase in tear and tensile indexes for bleached Eucalyptus paper, respectively. Incorporating CCNPs into non-refined paper yields physical traits akin to wood pulp paper beaten over 40 °SR. The CCNP-strengthened handsheets exhibited superior tensile and tear index in comparison to commercial dry strength additives such as cationic starch (CS) and cationic polyacrylamide (CPAM). Additionally, at 80 μg/ml concentration, E-B-9 displayed significant bactericidal effectiveness, achieving an impressive 97% reduction in Escherichia coli. This notable outcome is attributed to the presence of quaternary ammonium salt moieties in the formulation. This investigation introduces a promising approach where in the utilization of CCNP as an innovative multifunctional agent for paper holds the potential to enhance paper performance and concurrently reduce production costs. [Display omitted] ● The agro-waste CCNP acted well as a paper multifunctional addictive. ● The CCNPs promoted physical strengths of the paper from non-refined wood pulps. ● 9% CCNP-added sheet has mechanical properties akin to that from the 40°SR paper. ● 80 μg/ml of the bleached hardwood showed 97% bactericidal efficacy against E. coli. ● The improvement of CCNPs applied to bleached pulps is superior to unbleached pulps. [ABSTRACT FROM AUTHOR]

High-performance aramid papers are ideal insulating materials in the electric industry, due to their superior mechanical strength and insulation capabilities. However, when subjected to prolonged high-voltage and high-power operations, these papers are prone to electrical damage, such as breakdown or corona aging. Unfortunately, most damaged aramid papers are viewed as mere waste, discarded through landfill or other unsustainable disposal methods. It is not only contrary to circular economy principles but also poses a significant environmental threat due to the potential for pollution. Herein, a closed-loop recycling strategy is proposed that efficiently and effectively reclaims electrically damaged meta-aramid papers. Using the DMAc/LiCl deprotonation system, waste aramid papers are completely decomposed into molecular chains, exposing carbon residues resulting from electrical breakdown. These carbon residues are removed through a step-by-step purification process. A reprotonation treatment is then applied to regenerate new meta-aramid papers by reforming the intermolecular hydrogen bonds. This approach not only fully restores the original honeycomb-like structure but also ensures the crystallization and hydrogen bond content, maintaining both electrical and mechanical properties at above 90 % of their original values. Notably, our recycling method is also compatible with aramid-based composites, achieving exceptional recycling efficiency. [Display omitted] • Electrically damaged meta-aramid paper can be recycled in a closed loop. • The DMAc/LiCl system completely dissolves waste aramid into PMIA molecular chains. • Carbon residues induced by electrical breakdown can be removed by purification. • The synergistic conservation of electrical and mechanical properties exceeds 90 %. • Closed loop recycling strategy is also viable for inorganic-aramid composite paper. [ABSTRACT FROM AUTHOR]

In the present study, a biomimetic strategy concerning to surmount the predicament of strength-toughness tradeoff in the Ni matrix composite was carried out. By assembling Ti 3 AlC 2 -based preceramic papers with pure Ni foils alternatively, a novel kind of in-situ TiC/Ni-Ni 3 (Al,Ti) composite with a mimicking nacre architecture was successfully fabricated. The results show that the grain gradient of in-situ TiC combined with γ'-Ni 3 (Al,Ti) was generated in the composite layer and alloy layer, respectively. The interlayer interface was well-bonded without microvoids, flaws, or other defects. Ascribed to an excellent combination of hard-soft laminate architecture, grain gradient as well as superior interfacial bonding, a synergy of mechanical strength and toughness in the laminated TiC/Ni-Ni 3 (Al,Ti) composites was achieved. The Vickers hardness increases gradually along alloy layer, interface, and composite layer. The flexural strength and fracture toughness were ∼18 % and ∼92 % higher than the counterpart of homogeneous TiC/Ni-Ni 3 (Al,Ti) composite. The laminated architecture enhances the efficiencies of gradient TiC grains in mechanical strengthening for required bearing and loading transmission, and toughens composite materials by interfacial delamination, cracks deflection, bridging and blunting. • Inspired by natural nacre, an in-situ laminated Ni matrix composite was successfully fabricated. • Grain gradient of TiC and Ni 3 (Al,Ti) appears in composite and alloy layers, respectively. • Gradient interface was built through mutual diffusion of Ni-Al-Ti atoms. • Laminated TiC/Ni-Ni 3 (Al,Ti) composite shows excellent combination of strength and toughness. [ABSTRACT FROM AUTHOR]

Micro- and nano-hybrid cellulose fiber (MNCF) stands out as a versatile cellulosic nanomaterial with promising applications in various fields owing to its excellent intrinsic nature and outstanding characteristics. However, the inefficiency in preparing MNCF, attributed to a complex multi-step processing, hinders its widespread adoption. In this study, a straightforward and highly efficient method for MNCF preparation was developed via a hot water soaking-assisted colloid grinding strategy. Active water molecules in hot water facilitating stronger transverse shrinkage and longitudinal expansion in fiber crystallized region, and thus improving the fibrillation degree of cellulose fibers. As a result, MNCFs with a mean diameter of 37.5 ± 22.2 nm and high concentration (2 wt%) were successfully achieved though pure mechanical method. The micro and nano-hybrid structure leads to the corresponding resulting cellulose paper with micro- and nano-hybrid structure possesses a compact stacking and fewer defects, leading to extraordinary mechanical properties including tensile strength of 204.5 MPa, Young's modulus of 6.3 GPa and elongation of 10.1 %. This work achieves significant progress towards straightforward and highly efficient production of MNCFs, offering an appreciable prospect for the development of multifunctional MNCF-based materials. [ABSTRACT FROM AUTHOR]

Graphene-based nanomaterials have found significant interest in the development of embedded sensors to monitor the fracture behavior in composite structures. In this work, in-situ crack propagation and fracture behavior within a glass fiber reinforced polymer composite (GFRP) was monitored using embedded reduced graphene oxide (rGO) coated fabrics and highly conductive graphene nanoplatelet (GnP) paper. All laminates were fabricated using the resin infusion process. The piezoresistive performance of both types of laminates was evaluated using in-plane and out-of-plane mechanical tests. The effect of GnP paper thickness (50/150/240 µm) and loading rate was also evaluated using tensile and Mode-I fracture loadings. Piezoresistivity of the sensors was reduced by increasing loading rate during tensile tests. All laminates with GnP paper exhibited poor mechanical performance under tensile loading. The laminates with 50 µm GnP paper showed highest sensitivity under Mode-I loading. In comparison to pristine laminates, the interlaminar fracture toughness of laminates with 50 µm GnP paper was reduced by 70%. Furthermore, laminates with rGO coated fabrics demonstrated stable crack propagation under Mode-I loading as compared to GnP based laminates. The fractured surfaces were analyzed using scanning electron microscopy to investigate the underlying fracture mechanisms of the sensors in the composite laminates. [Display omitted] • Composites with embedded GnP paper and rGO coated fabric sensors were manufactured. • Sensor based on thin GnP paper was found more sensitive than the thick GnP sensors. • Loading rate and thickness effects on the sensing behavior were characterized. • Increasing the load rate during in-plane tensile tests decreases the sensitivity. • rGO based sensor exhibited high mechanical properties than the GnP based sensors. [ABSTRACT FROM AUTHOR]

AbstractCementitious materials are susceptible to cracking and spalling during service by various internal and external factors, while the long setting time and limited initial strength of Portland cement are insufficient for the repair project’s requirements. Cement can be categorized into Portland cement, sulphoaluminate cement, ferroaluminate cement, aluminate cement, phosphate cement, and fluoroaluminate cement based on various water-hardening ingredients. This paper summarized the performance of various cements and discussed the advancements in studying the impact of nanomaterials and major mineral admixtures (fly ash, silica fume, mineral powder, and slag) on the physical properties and mechanical properties of Portland cementitious materials and special cementitious materials. These additives can expedite the setting process, enhance flowability, and boost the strength of cementitious materials. This paper discussed the impact of nanomaterials and mineral admixtures on the hydration mechanisms of various cementitious materials. Mineral admixtures and nanomaterials can regulate the cementitious material hydration process and improve pore structure. On this basis, the problems to be studied in depth in the application of different kinds of cement in repair works were proposed. [ABSTRACT FROM AUTHOR]

Based on an analysis of the literature on fiber‐reinforced concrete (FRC), especially the development and formation of various types of FRC combined with reactive powder concrete (RPC) in recent years, this paper systematically expounds the research progress, particularly the mechanical properties, of steel fiber RPC, basalt fiber RPC and hybrid fiber RPC. This paper concludes the improvement in the mechanical properties of RPC under common curing methods, elaborates on the influence of steel fiber on the compressive, tensile, and flexural strength of RPC, and outlines the principle of fiber enhancing the mechanical properties of RPC. Additionally, it discusses the research progress in basalt FRC, and further examines the impact of basalt fiber on the mechanical properties of RPC. Referring to the research on single fiber reinforced RPC, the mechanical properties of hybrid fiber RPC are analyzed and summarized; based on the characteristics of steel fiber and basalt fiber, research on steel‐basalt hybrid fiber RPC is proposed. [ABSTRACT FROM AUTHOR]

Aircraft propulsion electrification is currently being considered by industry and academia as one of the most promising strategies to reduce air transport emissions and increase overall efficiency levels. In the past decade, several papers were published on this subject, with the majority indicating encouraging fuel burn benefits versus conventional, fossil-fuel-based propulsion systems when future technologies, novel aircraft configurations, and synergistic propulsive-airframe integration are employed. However, a much smaller effort has been applied to the economic aspects of hybrid and fully electric propulsion, which are crucial for a successful product introduction. The present paper describes the modeling of a baseline general-aviation-type aircraft and its propulsion system retrofit with electrified architectures, exploring different electrification strategies for a fixed airframe design. Analyses are performed at the aircraft level, comparing recurring and cash operating costs for several cost and durability scenarios. While considerable CO2 reductions may be achieved in some electrification strategies, aircraft performance is significantly penalized, and important improvements in economic figures of merit are needed in order to make electrified propulsion cost-competitive. Electrified architectures tend to increase costs: turboelectric increases recurring equipment costs, while hybrid-electric increases recurring and direct maintenance costs, especially at higher degrees of energy hybridization. [ABSTRACT FROM AUTHOR]

With the increasing drilling depth of mines, the cross-complexity of fissures in the rock body, and the frequent occurrence of sudden water surges, polymer slurry, with its advantages of good permeability and strong water plugging, is increasingly used in mine grouting projects. Additional research is needed in order to further improve the grouting performance of polymer slurry, ensure the safety of mining operations, and reduce the grouting cost. In this paper, a polymer composite grouting material was prepared with diphenyl methyl diisocyanate, polyether polyol, and fly ash, as the main raw materials, with coupling agent and catalyst as auxiliary reagents. The performance of the composite grouting material in terms of mechanical properties, thermal stability, hydrophobicity, and bonding was explored. This study's findings indicated that incorporating fly ash led to notable enhancements in the thermal stability and water resistance of the polymer slurry. Furthermore, the introduction of fly ash notably raised the starting degradation temperature of the polymer, boosted the water contact angle of the composite material, and reduced the density and reaction temperature of the composite material. In addition, the catalyst and coupling agent as auxiliary reagents affected the polymers in terms of mechanical properties; in this paper, dibutyltin dilaurate was used as the catalyst, and organosilanes were used as the coupling agent. The catalyst successfully sped up the polymer's gel time, however, an excessive quantity of catalyst compromised the polymer's mechanical characteristics. The addition of organosilanes has a positive effect on the dynamic mechanical properties of the composites, fracture toughness, compression, bending, and bond strength. The research can offer a theoretical direction for creating polymer mixtures in mine grouting projects. [ABSTRACT FROM AUTHOR]

The ceramic materials studied in this paper consist of finely dispersed crystalline phases embedded in a glassy matrix, which is similar to glass-ceramic materials, porcelain, and VC products. The strength depends then not only on the properties of the individual crystalline phases but also on their interactions and the matrix. Differences in mechanical properties for materials with similar chemical compositions are most likely related to diverging microstructures. Crystal orientation, grain-size distribution and shape, the ratio of the glass matrix to the crystalline phase, and homogeneity control the flexural strength of glass-ceramic materials. The subject of the study is whiteware ceramic materials from the SiO 2 –Al 2 O 3 –Na 2 O–K 2 O–MgO–SrO system, fired similarly to the regime used for VC products. The effect of the type of alkali oxide and the share of SrO were tested. This paper presents the results of hot-stage microscopy, X-ray diffraction (XRD), scanning electron microscopy with a micro-analyzer (SEM-EDS) and biaxial flexural strength measurements. Additionally, nanoindentation technique was used to access local mechanical properties. [ABSTRACT FROM AUTHOR]

The article presents continued considerations presented in a prior publication on the development of a model for calculating the bending stiffness BS of cellular honeycomb paperboards, applying the strength properties of paper raw materials used for the production of paperboard and the geometric parameters of cellular board. The results of BS calculations obtained by using the analytical model presented in the prior publication were significantly overestimated in relation to the value obtained by measurements. The calculation error in relation to the measurement value for the tested group of paperboards in the case of bending stiffness in the machine direction MD was within the range from 23% to 116%, and the average error was 65%, while in the cross direction CD, it was within the range from 2% to 54%, and the average error was 31%. The calculation model proposed in this work based on the physical properties of cellular paperboard reduces the error values for bending stiffness in both the machine and cross directions. The value of the average error for both main directions in the paperboard plane was 10%. The method enables more accurate determination of BS in the machine direction MD and in the cross direction CD at the paperboard design stage. In order to validate the proposed analytical model, the calculation results were compared with the results of BS laboratory measurements performed using the four-point bending method and, in order to expand the group of tested paperboards, with the measurement results presented in the prior article for cardboards with different raw material composition and different geometric parameters. [ABSTRACT FROM AUTHOR]

Before artificial ageing, extruded aluminium profiles are subjected to stretching with a small cold deformation in the range of 0.5–2%. This deformation improves the geometrical stability of the extruded product and causes changes in the microstructure of the profile, which leads to the strain hardening of the material after artificial ageing. The work has resulted in the creation of the prototype of an original device, which is unique in the world, for the dynamic stretching of the extruded profiles after quenching. The semi-industrial unit is equipped with a hydraulic system for stretching and a pneumatic system for cold dynamic deformation. The aim of this research paper is to produce advantageous microstructural changes and increase the strength properties of the extruded material. The solution of the dynamic stretching of the profiles after extrusion is a great challenge and an innovation not yet practised. The paper presents the results of microstructural and mechanical investigations carried out on extruded AlMgSi(Cu) alloys quenched on the run-out table of the press, dynamically stretched under different conditions, and artificially aged for T5 temper. Different stretching conditions were applied: a static deformation of 0.5% at a speed of 0.02 m/s, and dynamic deformation of 0.25%, 0.5%, 1%, and 1.5% at speeds of 0.05 and 2 m/s. After the thermomechanical treatment of the profiles, microstructural observations were carried out using an optical microscope (OM) and a scanning electron microscope (SEM). A tensile test was also carried out on the specimens stretched under different conditions. In all the cases, the dynamically stretched profiles showed higher strength properties, especially those deformed at a higher speed of 2 m/s, where the increase in UTS was observed in the range of 7–18% compared to the classical (static) stretching. The microstructure of the dynamically stretched profiles is more homogeneous with a high proportion of fine dispersoids. [ABSTRACT FROM AUTHOR]

The continuous upgrading of the automobile industry has put forward higher requirements for the performance and lightweight effect of aluminum alloys. Heat treatment is an effective way to improve the performance of aluminum alloy, but how to obtain the optimal combination of heat treatment process parameters is an urgent problem. In this paper, the influence of heat treatment process parameters (solution temperature, solution time, aging temperature, aging time) on mechanical properties was systematically studied, and the relationship model between mechanical properties and heat treatment process parameters was established. The micromorphology under different process parameters were analyzed by ESDB and SEM. The results show that when the solution temperature was 530 ℃, the solution time was 1 h, the aging temperature was 170 ℃, and the aging time was 6 h, the mechanical property of 6082 aluminum alloy profiles was the best. The yield strength was 313 MPa, the tensile strength was 350 MPa, and the elongation after break was 13.21%. The relationship model between Y value (yield strength, tensile strength, and elongation after fracture) and key process factors was established, in which the solution temperature had the greatest influence. When the solution temperature was 530 ℃, the grain size was the smallest, and the mechanical properties of the precipitated fine Mg2Si phase and Al(FeMnSi) phase were the best, and the tensile fracture was mainly the dimpled fracture. This paper provides theoretical basis and practical guidance for the optimization of heat treatment process parameters of aluminum alloy profiles. [ABSTRACT FROM AUTHOR]

Context and results : In this paper, the crystal structure, electronic, optical, and mechanical properties of SrVO3 have been systematically studied by first-principles calculation. The results show that the calculated lattice parameters are in good agreement with the experimental values of X-ray diffraction. The density of states is described in detail in this paper. By analyzing the crystal structure and electronic properties of SrVO3, the magnetic properties of SrVO3 are obtained from the one unpaired electrons of V and the exchange interaction between two V ions. At the same time, a detailed analysis of the optical properties of SrVO3 was conducted, and it was found that it is transparent in the visible light range. Finally, the mechanical properties of SrVO3 are calculated, which can provide some references for future research. Computational method: In this paper, a first-principles method based on density functional theory (DFT) is reported for PBE-GGA analysis using the plane wave-pseudo potential method in a quantum concentrate packet, U value of 7 eV to V-d and a U value of 2 eV to O-p, Grimme correction by DFT-D method. The k points in the Brillouin region are set to 4 × 4 × 4. The energy convergence criterion for self-consistent field calculation is set at 5.0 × 10−6 eV/atom, and the cutoff energy is 1170 eV. In this paper, the force acting on each atom is not more than 0.01 eV/Å, the maximum stress is not more than 0.02GPa, and the maximum atomic displacement is 5 × 10−4 Å. [ABSTRACT FROM AUTHOR]

Many researchers are interested in using natural fibres to treat due to recent advancements in polymer characteristics. The mechanical properties of three types of bars are studied in this paper: Cotton Fibre-Reinforced Polymer bars, Cotton/Carbon Fibre-Reinforced Polymer bars, and Cotton/Glass Fibre-Reinforced Polymer bars. The goal of the paper was to create low-cost bars with comparable mechanical performance and corrosion resistance to steel reinforcement. The bars were made using two methods: fibres immersed in polymer and fibres coated with polymer by repeated tension and relaxation of fibres. The second method produced better results in terms of the tensile strength of Cot.CFRP, Cot.GFRP, and Cot.FRP bars, which were 688, 477, and 284 MPa, respectively, and the stress–strain curve revealed brittle behaviour for all bars and modulus of elasticity of 43, 31 and 22 GPa. When sand was put on the bar's surface, the bars demonstrated a good connection with the concrete. It also showed good resistance to moisture, alkaline solutions and acids, as well as heat resistance at temperatures below 200°C. [ABSTRACT FROM AUTHOR]

Beech wood, renowned for its diverse applications spanning construction, flooring, furniture, veneer, and plywood, holds a paramount position among industrial wood species. Nevertheless, the myriad of beech species worldwide, coupled with the dynamic impact of climate change, have produced structural variations within beech trees. Extensive research has scrutinized the physical and mechanical attributes of beech wood species across the globe. Findings reveal distinguishable mechanical strength, yet increased density leads to notable rates of shrinkage and swelling, somewhat constraining its utility in select domains. Identifying research gaps can create new efforts aimed at exploiting the potential of these wood resources. This paper outperforms a mere exploration of beech wood properties over the past two decades; it delves into the ramifications of climatic fluctuations, temperature shifts, wind dynamics, and soil composition. Given the lack of a comprehensive compendium documenting the full range of physical, mechanical, and microscopic attributes of the Fagus genus, this paper aims to compile information that integrates this multifaceted information. [ABSTRACT FROM AUTHOR]

The surfaces of engineering components experience severe conditions during service life and may lead to catastrophic failure if proper care is not taken. The coating is one of the best possible ways to enhance surface properties of a part. Tungsten inert gas (TIG) cladding has emerged as a new technique which shows promising results in surface cladding domain. This paper deals with the recent developments in TIG cladding process. The processing parameters associated with the TIG cladding process are discussed. The microstructure, microhardness, wear, and corrosion behavior of the TIG-cladded layers are mentioned and correlated with the processing conditions. Finally, this paper concludes with some suggestions for future research. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach to enhance the energy absorption (EA) of honeycombs in the out-of-plane direction. Inspired by the Koch fractal, a fractal hexagonal honeycomb (FHH) is presented in this paper. In our study, we use Abaqus/Explicit to build a finite element model of the honeycomb, through which we conduct a series of studies on the performance of this honeycomb. Initially, we compare the mechanical properties and deformation modes of the FHH with those of a conventional hexagonal honeycomb. The results demonstrate notable improvements in crashworthiness metrics for the FHH, including a 52% increase in specific EA, a 45% enhancement in crushing load efficiency (CLE), and an 8% reduction in peak crushing force (PCF) compared to the conventional counterpart. Subsequently, this paper investigates the fractal arc honeycomb and evaluates the effect of the center angle on mechanical properties by varying its value. Furthermore, the mechanical properties of layered honeycomb and fractal honeycomb structures with different wall thicknesses are systematically examined. In the last section, we explore the theoretical analysis of the fractal-hexagonal honeycomb and find that the results of the theoretical analysis are in good agreement with those of the simulation, indicating that the experimental simulation results are reliable. Overall, the findings of this study offer valuable insights for the innovative design of hexagonal honeycomb structures, providing a reference for future advancements in this field. [ABSTRACT FROM AUTHOR]

Recently, composite PVDF membranes with good performance have triggered enormous interest because of their great potential application. However, the uncertainty of mechanical properties limits their application. Herein, this paper reveals the elastic modulus properties of the loading angle between warp and tensile direction using the uni-axial tensile test of SH-1050P membrane textile. In addition, the bi-axial tensile test with different loading ratios was implemented. Both uni-axial and bi-axial ductile load-displacement/stress-strain curves are featured. It is the first to establish a relationship between the elastic modulus and the loading angle using a theoretical method based on the assumption that there is no slippage and crease between yarns and matric. Furthermore, simulations with different textile parameters were carried out to verify the theoretical results. The key finding is that the elastic modulus under uni-axial load can be divided into two stages, which are elasticity and plasticity. Both of which are proportional to the sine function applied to two times the loading angle. The Poisson's ratio of SH-1050P textile can be considered as a fixed value of 0.11. This conclusion can be extended to similar textiles. The outcome of this paper contributes to a deeper understanding of the PVDF memrane's mechanical behavior and presents a novel insight into its response to different loading conditions. [ABSTRACT FROM AUTHOR]