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Recently, we presented a method to assign atomic partial charges based on the DASH (dynamic attention-based substructure hierarchy) tree with high efficiency and quantum mechanical (QM)-like accuracy. In addition, the approach can be considered "rule based"—where the rules are derived from the attention values of a graph neural network—and thus, each assignment is fully explainable by visualizing the underlying molecular substructures. In this work, we demonstrate that these hierarchically sorted substructures capture the key features of the local environment of an atom and allow us to predict different atomic properties with high accuracy without building a new DASH tree for each property. The fast prediction of atomic properties in molecules with the DASH tree can, for example, be used as an efficient way to generate feature vectors for machine learning without the need for expensive QM calculations. The final DASH tree with the different atomic properties as well as the complete dataset with wave functions is made freely available. [ABSTRACT FROM AUTHOR]

The interplay between individual capacities and group performance provides insights for different tasks and contexts. So far, little is known about the individual capacities of base and top gymnasts and mechanical efficiency during pair tasks of Acrobatic Gymnastics. This work aims to investigate: (1) the effect of the pair experience in the mechanical efficiency during a pair task; (2) the effect of the individual training experience in the gymnasts’ individual capacities, and (3) the contribution of individual capacities and pair mechanical efficiency to the performance of a partner-assisted flight task. Twelve pairs from national first division and elite levels performed a pair task and individual tests and were divided into pair and individual experience levels. Results showed that experience improves the pair task efficiency and individual performances, with distinct implications for each role. Mechanical efficiency is crucial for partner-assisted flight, but the individual capacities of base and top gymnasts also have an important contribution, followed by mass differences, and the pair experience. Coaches should focus on understanding how different experienced gymnasts can combine their capacities to collaborate efficiently. Also, considering the predictable increase in top gymnast’s mass over time, to improve technical efficiency and individual physical condition. [ABSTRACT FROM AUTHOR]

Producing ceramic parts by Vat Photopolymerization (VPP) additive manufacture with desired mechanical properties typically requires time‐consuming debinding steps. This study aims at optimizing composition and processing parameters with the use of dibutyl phthalate (DBP) in the resin formulation and debinding in an argon atmosphere for dental zirconia‐toughed alumina (ZTA). The method produces parts with fewer defects, and 67.7% higher flexural strength while increasing the debinding heating rate over 400% compared to standard formulations debinded in air. These improvements are attributed to pore formation at low temperatures and reduced heat release and gas evolution rates arising from use of the DBP and the inert atmosphere, respectively. While ZTA ceramics were studied, this method should be applicable to many ceramic systems with exciting possibilities for promoting the rapid development of VPP 3D‐printed high‐performance ceramics for various engineering applications. [ABSTRACT FROM AUTHOR]

The efficiency of mechanical pulping has long been of interest due to the large energy consumed by the process. Previous estimates of theoretical efficiency have accounted for less than 20 % of the energy employed. In this study, we make new estimates based on fracture mechanics and abrasion as the mechanisms of new surface creation. We postulate that fracture mechanics comminutes wood into fibres and creates pores in fibre walls. This consumes around 100 kWh/t. Abrasion peels surface material from fibres in the form of morphologically different fines particles. Based on abrasion theory, we estimate this specific energy to be around 1,330 kWh/t. Together, fracture mechanics and abrasion, account for about 70 % of the specific energy (2,000 kWh/t) to produce TMP for printing paper grades. We postulate that the remaining energy is consumed as hysteresis losses from viscoelastic strains not linked to creation of new surface. The largest single source of energy consumption, abrasion, alone accounts for about 66 % of the energy of the process. Finally, we discuss how energy may be reduced by refining intensity and other means. [ABSTRACT FROM AUTHOR]

This study investigates the development of epoxy–resin composites reinforced with coral-derived calcium carbonate (CaCO3) fillers for enhanced radiation shielding and mechanical properties. Leveraging the high calcium content and density of coral, composites were prepared with filler weight fractions of 0%, 25%, and 50%. SEM and EDS analyses revealed that higher filler concentrations (50%) increased particle agglomeration, affecting matrix uniformity. Mechanical testing showed that while the tensile and flexural strengths decreased with the increased filler content, the compressive strength significantly improved, reaching 135 MPa at a 50% coral content. Radiation shielding evaluations demonstrated enhanced attenuation with a higher filler content, achieving 39.63% absorption at 60 kVp for the 50% coral composite. However, the shielding efficiency was notably lower compared to lead, which achieves over 99% absorption at similar energy levels. These quantitative comparisons highlight the material's limitations in high-radiation environments but emphasize its suitability for moderate shielding applications. Despite their lower shielding efficiency, the composites provide an environmentally friendly and non-toxic alternative to lead, aligning with sustainability goals. Future work should focus on optimizing filler dispersion, mitigating agglomeration, and exploring hybrid systems to enhance the shielding efficiency and mechanical properties. The further quantitative evaluation of parameters such as Zeff and cross-sections is recommended to comprehensively assess the material's performance. [ABSTRACT FROM AUTHOR]

Flexible perovskite solar cells (F-PSCs) have the advantages of high power-per-weight, solution processability, and bending durability and have emerged as a competitive photovoltaic technology for various applications. As the core electron transport layer (ETL) in n-i-p-type device configurations, the solution-processed SnO2 generally suffers from serious defect stacking on films, compromising the charge transport properties and the performance of resulting devices. Herein, we proposed a media-filling strategy to optimize the contact quality at the buried interface by introducing Al2O3 nanoparticles on the SnO2 surface. Rather than forming a compact insulating layer, the Al2O3 can fill the grain boundaries of SnO2 and smooth the substrate surface. Optimized interfacial contact under careful concentration control can rationally minimize the contact area of the perovskite with the surface imperfections of SnO2 to mitigate trap-assisted charge recombination. Furthermore, the reduced surface roughness of SnO2 facilitates the uniform deposition and oriented growth of upper perovskite film. As a result, the target F-PSCs achieved an impressive efficiency of 23.83% and retained 80% of the initial performance after 5000 bending cycles at a radius of four mm. [ABSTRACT FROM AUTHOR]

The residential sector is one of the main sectors responsible for the atmospheric emission of CO2. Hence, a significant effort is required to develop technological solutions to enable decarbonization. The integration of Organic Rankine Cycle (ORC)-based units with renewable sources at a micro-scale of cogeneration units is commonly believed to be one of the most important technological alternatives. Indeed, an ORC-based unit allows the exploitation of low-temperature heat sources in the production of electricity. The low power scale of this application (1–5 kW) and the severe operating conditions call for the reliable and proper design of components. Particularly critical is the pump, as the experimental analyses available in the literature show its efficiency rarely exceeds values of 0.3. The most suitable technology is volumetric, and among those available, the sliding vane types are interesting candidates. However, low efficiency leads to a significant erosion of the power produced by the expander, limiting the achievement of high-efficiency values. What is more, in the literature, there is a lack of development of optimization strategies to improve the performance of this machine. To fill this knowledge gap, in this present paper an optimized sliding vane rotary pump was designed. Thanks to a comprehensive experimentally validated model, the pump performance was assessed for a wide range of operating conditions. Results confirmed that a disk-shaped configuration also ensures the best efficiency is achieved for small-scale pumps. Moreover, the model allowed for a detailed analysis of efficiency, evaluating the volumetric, fluid dynamic and mechanical behaviors. Results demonstrated that the weakest point was the mechanical efficiency, which was between 0.45 and 0.55. The best configuration was that involving four blades, the adoption of graphite and a clearance gap between the rotor face and casing of 10 μm. These design solutions improved efficiency by up to 25%, with a maximum value equal to 0.50, which is close to double with respect to the usual values. A final remark concerns the operating robustness of the machine, as the efficiency demonstrated weak variations even when wide operating conditions were considered. [ABSTRACT FROM AUTHOR]

Introduction Foot-borne soldiers sometimes carry out nighttime operations. It has previously been reported an elevated metabolic demand and impaired walking economy during outdoor walking on a gravel road in darkness wearing night vision goggles (NVG), compared with wearing a headlamp. The aim of the present study was to evaluate the effect of wearing NVG while walking in a hilly forest terrain and compare the results between experienced and inexperienced NVG users. Materials and Methods At nighttime, two different groups, inexperienced (five men and six women) and experienced (nine men) NVG users, walked 1.1 km at a self-selected comfortable pace in a hilly forest. Part I was mainly uphill, and Part II was mainly downhill. Walks were performed wearing a headlamp (light), monocular NVG (mono), binocular NVG (bino), or mono with a 25 kg extra weight (backpack). Walking economy calculated from oxygen uptake in relation to body mass and covered distance (V̇O2 (mL/[kg · km])), heart rate, gait, and walking speed were measured. Results In both groups, walking economy was deteriorated in all three conditions with limited vision (mono, bino, and backpack) compared to the light condition, both during Part I (mono/bino, experienced: +26/+25%, inexperienced: +34/+28%) and Part II (mono/bino, experienced: +44/+46%, inexperienced: +63/+49%). In the backpack condition, the relative change of walking economy was greater for the inexperienced group than the experienced group: Part I (experienced: +46%, inexperienced: +70%), Part II (experienced: +71%, inexperienced: +111%). Concurrently, the step length was shorter in all three conditions with limited vision during Part I (mono/bino/backpack, experienced: −7/−7/−15%, inexperienced: −12/−12/−19%) and Part II (mono/bino/backpack; experienced: −8/−8/−14%, inexperienced: −17/−15/−24%) than in the light condition. The experienced NVG users walked faster during all conditions, but there was no difference in heart rate between groups. Conclusions Despite that foveal vision using NVG is adequate, it appears that the mechanical efficiency during nighttime walking in hilly terrain was markedly lower while wearing NVG than with full vision, regardless of whether the soldier was an experienced or inexperienced NVG user. Moreover, the walking economy was even more affected when adding the 25-kg extra weight. It is probable that the deteriorated mechanical efficiency was partly due to the shorter step length in all three conditions with limited vision. [ABSTRACT FROM AUTHOR]

As the primary power equipment in pump flooding cooling systems, the efficiency and performance of mechanical pumps play a crucial role in two-phase cooling systems. A high-speed centrifugal pump with self-lubricating working fluid was designed with a speed of 7500 rpm and a flow coefficient of 0.0506. The hydraulic and cavitation performance of the pump were tested with R134a as the working fluid. The results show that the working fluid pump is capable of efficiently pumping R134a with an efficiency of 40.3 % and a head coefficient of 0.988 under the design condition. Within the tested range of inlet temperature from 5°C to 15°C, the flow coefficient from 0.01 to 0.105, and the height of the refrigerant tank from 1.4 m to 5 m, lower net positive suction heads available at the same flow rate will reduce the pump head, increase power consumption, and decrease efficiency. Increasing the pump speed from 3000 rpm to 7500 rpm can improve the pump's performance. At 6000 rpm, the critical cavitation number of the working fluid pump increases with the increase in flow coefficient. At 7500 rpm, the critical cavitation number has a minimum value when the flow coefficient φ = 0.0434. At the design speed and flow rate, both the critical cavitation coefficient and fracture cavitation number increase as the inlet temperature decreases. The inducer can significantly reduce the critical cavitation number of the pump. Finally, an empirical correlation considering the thermodynamic effects is proposed to predict the increase in the critical cavitation number. [ABSTRACT FROM AUTHOR]

The current research aims to analyse the effect of the number and shape of the blades and the curvature of the flume bottom on the performance curves of undershot water wheels, based on experimental tests conducted in a fully instrumented laboratory facility. Six wheels are tested: four wheels with plane blades (16, 24, 36, 48) and two with 24 curved blades for two flume bottom configurations. Torque, mechanical power and mechanical efficiency performance curves are determined for several rotational speed and flow rate values. Results demonstrate that the maximum efficiency is achieved for the 36-plane blade wheel, the curved flume bottom reduces water losses under the wheel and increases efficiency, and the blades' shape strongly influences the wheel efficiency. Non-dimensional performance curves are provided to generalise the results. This research provides relevant contributions towards the development of a low-cost energy recovery solution to be applied in water infrastructures. [ABSTRACT FROM AUTHOR]

This study investigates the role of static allometry in modulating sexual shape dimorphism in the snapping and cutting claws of Alpheus species. We hypothesize that the static allometry in adulthood can promote an exaggeration of existing sexual dimorphism in the snapping and cutting claws of Alpheus. Sexually mature pairs from three species (Alpheus angulosus , Alpheus carlae , and Alpheus nuttingi) were analyzed using geometric morphometric techniques. The increase in size claw enhances the robustness of both snapping and cutting claws. Since males carry larger weapons compared to females, the static allometry provides more robustness in their weapons. These findings support our hypothesis. Due to the effect of static allometry, male weapons exhibit a more robust pollex, while female weapons exhibit a more robust palm in the snapping claw. Sexual shape dimorphism is less pronounced in the cutting claw, although males display larger and more robust claws compared to females. Static allometry amplifies the sexual differences in Alpheus weapons, emphasizing the role of sexual selection in the evolution of claw morphology. The results suggest that sexual selection favors larger, more robust claws in males, thus enhancing their effectiveness in agonistic contests. • The static allometry amplifies the sexual shape dimorphism in all three species. • The static allometry leads to larger weapons, with a more robust pollex in males. • Males and females of all species have distinct snapping claw shapes. • The palm of the female snapping claw can generate higher mechanical efficiency. [ABSTRACT FROM AUTHOR]

In this work, Al–Mg alloys fabricated by combining continuous rheo-extrusion (CRE) and Sc modification were proposed for producing Al–Mg alloys with high efficiency and superior mechanical performance. The microstructural evolution and mechanical property response of the CREed Al–5Mg alloy with Sc modification were investigated. The grain refinement and strengthening mechanisms induced by nanoscale Al3Sc-phase particles in the alloy were discussed. The results showed that an obvious grain refinement effect was achieved in the CREed Al–5Mg alloy as the Sc content increased from 0 to 0.5 wt%, and the average grain size decreased from 52.6 μm to 2.4 μm, respectively. The primary Al3Sc-phase particles formed during solidification behaved as heterogeneous nucleation sites for the α-Al matrix, while the nanoscale Al3Sc-phase particles achieved during CRE enhanced the driving force of continuous dynamic recrystallization and the Zener drag force. As a result, a superior grain refinement effect was observed. The ultimate tensile strength, yield strength, and hardness of the alloy were enhanced as the Sc content increased from 0 to 0.5 wt%. Grain boundary strengthening, second-phase strengthening, and dislocation strengthening were the main strengthening mechanisms of the CREed Al–Mg–Sc alloys. [ABSTRACT FROM AUTHOR]

Single-sided formwork supporting systems (SFSSs) play a crucial role in the urban construction of retaining walls using cast-in-place concrete. By supporting the formwork from one side, an SFSS can minimize its spatial footprint, enabling its closer placement to boundary lines without compromising structural integrity. However, existing SFSS designs struggle to achieve a balance between mechanical performance and lightweight construction. To address these limitations, an innovative instrumented SFSS was proposed. It is composed of a panel structure made of a panel, vertical braces, and cross braces and a supporting structure comprising an L-shaped frame, steel tubes, and anchor bolts. These components are conducive to modular manufacturing, lightweight installation, and convenient connections. To facilitate the optimal design of this instrumented SFSS, a physics-constrained generative adversarial network (PC-GAN) approach was proposed. This approach incorporates three objective functions: minimizing material usage, adhering to deformation criteria, and ensuring structural safety. An example application is presented to demonstrate the superiority of the instrumented SFSS and validate the proposed PC-GAN approach. The instrumented SFSS enables individual components to be easily and rapidly prefabricated, assembled, and disassembled, requiring only two workers for installation or removal without the need for additional hoisting equipment. The optimized instrumented SFSS, designed using the PC-GAN approach, achieves comparable deformation performance (from 2.49 mm to 2.48 mm in maxima) and slightly improved component stress levels (from 97 MPa to 115 MPa in maxima) while reducing the total weight by 20.85%, through optimizing panel thickness, the dimensions and spacings of vertical and lateral braces, and the spacings of steel tubes. This optimized design of the instrumented SFSS using PC-GAN shows better performance than the current scheme, combining significant weight reduction with enhanced mechanical efficiency. [ABSTRACT FROM AUTHOR]

In order to explore the influence of change in the structural parameters ofguide vane cyclones on the cyclone spinning effect, this paper mainly used numerical simulations and physical experiments to analyze the energy of the hydrodynamic flow of acyclone with different guide vane heights by taking the structuralparameters of the guide vane height as the research object. The results show that the rotational kinetic energy of the water flow inside the cyclone was almost zero in the upstream and straight sections of the guide vane section, and it only existed in the leading edge section of the guide vane. In the twisted section of the guide vane, the rotational kinetic energy increased along the flow path, while it decreased in the downstream section of the guide vane. An increase in the height of the guide vanes led to an increase in local mechanical energy loss at the leading and trailing edges of the guide vanes of the cyclone. In the guide vane section, the mechanical energy loss of the water flow remained almost constant along the path, but the mechanical energy loss was faster for cyclones with greater heights. During the deflection of the guide vane, pressure energy was converted into kinetic energy, and the higher the height of the guide vane, the greater the kinetic energy growth and mechanical energy consumption. The proportion of additional mechanical energy loss in the total loss increased with the increase in guide vane height, and the influence of guide vane height was greater than that of the Reynolds number. The mechanical efficiency ηdecreased with the increase in guide vane height, whereas the mechanical efficiency increased slightly with the increase in Reynolds number. The research results in this paper provide a theoretical basis for further optimizing the structural parameters of cyclones. [ABSTRACT FROM AUTHOR]

[Objective] Integrated irrigation and fertilization has been increasingly used as a water- and fertilizersaving technology in modern agriculture. However, conventional equipment often suffers from low mechanical efficiency and poor synchronization of water and fertilizer application, limiting its effectiveness. To address these limitations, we designed and evaluated a high-efficiency fertilization pump for integration into irrigation systems. [Method] The device was designed based on the equal-section double-acting pump. We analysed the internal flow characteristics in the pump and established a numerical model to simulate fertiliser flow in the inlet and outlet channels, as well as in the chamber. The k-epsilon turbulence model with enhanced wall treatment wall function was used to increase modelling accuracy. All simulations were conducted using the Fluent software. We first verified that the simulated results met the design requirements for continuous fertiliser flow in the inlet and outlet channels and uniformity of fertilizer application, and then conducted a comparative experiment using the plunger pump and the traditional Venturi fertilizer pump to compare the electric conductivity (EC) of solution in the inlet and outlet channels, as well as the mechanical efficiency of the two pumps.[Result] The simulated results indicated that the new device achieved continuous and uniform fertilizer application. The experimental results showed that the variance in the EC of the solution in the inlet and outlet of the new device was less than 48.5, a significant improvement compared to the variance of 814.8 in the Venturi pump. Furthermore, the new device reduced the fluctuation by 54%; the mechanical efficiency of the new device at 0.30 MPa of working pressure was 56% higher than that of the Venturi pump.[Conclusion] The equal-section double-acting plunger pump demonstrated significant improvements in mechanical efficiency, precise fertilizer application, and seamless integration into waterfertilizer systems. These findings provide valuable insights for optimizing fertiliser application equipment, improving structural design and commercial applications of integrated fertilisation and irrigation apparatus in modern agriculture. [ABSTRACT FROM AUTHOR]

Hyaluronic acid hydrogels are promising materials for diverse applications, yet their potential is hampered by limitations such as low self‐healing efficiency and insufficient mechanical strength. Inspired by the heterogeneous structures of spider silk, we introduce a novel dual dynamically crosslinked network hydrogel. This hydrogel comprises an acylhydrazone‐crosslinked network, utilizing aldehyde hyaluronic acid (AHA) and 3,3′‐dithiobis (propionohydrazide) (DTP) as a first network, and a secondary network formed by hydrogen bonds‐crosslinked network between tannic acid (TA) and silk fibroin (SF) with β‐sheet formation. The hydrogel exhibits exceptional self‐healing ability due to the dynamic and reversible nature of Schiff base bonds, disulfide bonds, and hydrogen bonds, achieving complete healing within 5 minutes. Additionally, the spider silk‐inspired heterogeneous structures enhance mechanical properties. Furthermore, the incorporation of TA provides enhances adhesion, as well as remarkable antibacterial and antioxidant properties. This innovative hyaluronic acid‐based hydrogel, inspired by spider silk, offers a promising avenue to fortify both the mechanical strength and self‐healing capabilities of hydrogels, thus expanding opportunities for applications in tissue engineering and biomedicine. [ABSTRACT FROM AUTHOR]

Highlights To meet the urgent demands of aerospace vehicle upgrades and replacements, which require honeycomb structures with higher specific strength and environmental adaptability, the development of lightweight and high‐strength short‐cut carbon fiber reinforced polymer (S‐CFRP) honeycombs is an effective approach. First, this study designed a hot pressing process, which was utilized for the fabrication of both short‐cut CF paper and S‐CFRP honeycomb. Second, a finite element model was established to predict the mechanical performance of the S‐CFRP honeycomb. Finally, mechanical experiments were conducted on the S‐CFRP honeycomb and the failure factors were analyzed. The S‐CFRP honeycomb features cell edges as low as 2.75 mm in length, with a density reduced to 47.6 kg/m3, achieving the coexistence of small cell edge length and low density in the honeycomb structure. Compared with the aramid honeycomb of 48.06 kg/m3 from Hexcel Corporation, the compressive strength of the S‐CFRP honeycomb was increased by 21%, and the shear strengths in the L and W directions were improved by 42% and 59%, respectively. This study provides a fabrication method and simulation model for low‐cost, lightweight, high‐strength S‐CFRP honeycombs, which has significant engineering value for enhancing the weight reduction efficiency and the mechanical performance of aircraft structures. A low‐cost, high‐strength short‐cut CF paper has been prepared. An S‐CFRP honeycomb, lightweight and with small cells, has been made. The strength of S‐CFRP honeycombs exceeds that of aramid ones. The failure factors of the S‐CFRP honeycomb were analyzed. Performed accurate mechanical simulation analysis on S‐CFRP honeycomb. [ABSTRACT FROM AUTHOR]

Cardiac sex-difference functional studies have centred on measurements of twitch force and Ca2+ dynamics. The energy expenditures from these two cellular processes: activation (Ca2+ handling) and contraction (cross-bridge cycling), have not been assessed, and compared, between sexes. Whole-heart studies measuring oxygen consumption do not directly measure the energy expenditure of these activation-contraction processes. In this study, we directly quantified these energy expenditures in terms of heat production. Left-ventricular trabeculae were dissected from rats aged 9–13 weeks. Mechano-energetics of trabeculae were characterized using our work-loop calorimeter under various conditions including varying muscle lengths, stimulus frequencies, and afterloads. Each trabecula was subjected to protocols that allowed it to contract either isometrically or shorten to perform work-loops. Force production, length change, and heat output were simultaneously measured. We extracted various metrics: twitch kinetics, shortening kinetics, mechanical work, and heat associated with cross-bridge cycling and Ca2+ cycling, and quantified mechanical efficiency. Results show no sex differences in any of the metrics. Peak mechanical efficiency was not affected by sex (10.25 ± 0.57% in female trabeculae; 10.93 ± 0.87% in male trabeculae). We conclude that cardiac mechanics and energetics are not affected by sex at the muscle level, within the rat age range studied. [ABSTRACT FROM AUTHOR]

This study investigates the tensile behavior of carbon-fiber-reinforced polymer (CFRP) and textile-reinforced mortar (TRM) under various design variables to enhance understanding and application in construction structures. TRM reinforced with CFRP grids is highly effective for strengthening existing structures due to its lightweight nature, durability, ease of installation, and corrosion resistance. The research aims to evaluate how design parameters such as the CFRP grid type, mortar matrix strength (influenced by the water-to-cement ratio), specimen length, and grid width affect TRM's mechanical properties. Through the direct tensile test using a universal testing machine, TRM specimens were subjected to load until failure, with data collected on stress–strain relationships, crack patterns, and strengths. Specimens included untreated CFRP grids (Groups KC, Q47, and Q85) and sand-coated CFRP grids (Specimens AQ47_7 and AQ85_7), each tested under controlled laboratory conditions. The results indicate that crack formation significantly influenced load transfer mechanisms within the specimens, with longitudinal strands bearing load as cracks propagated through the mortar matrix. The presence of sand-coated CFRP grids notably enhanced interfacial bond strength, leading to increased cracking strength and ultimate strength compared with their untreated counterparts. The findings underscore the importance of the surface treatment of CFRP grids for improving TRM performance, with implications for enhancing structural integrity and durability in practical applications. The results provide valuable insights into optimizing TRM design for better crack control and mechanical efficiency in infrastructure. [ABSTRACT FROM AUTHOR]

Ceramics with controlled porosity are used as bio‐scaffolds, insulators, electrodes and lightweight materials. While their high surface area and low weight are attractive functionalities, such porous ceramics often suffer from poor mechanical properties and need energy‐intensive, high‐temperature sintering for manufacturing. The present work reports a low‐temperature approach for the manufacturing of mechanically efficient porous ceramics. The process relies on the 3D printing of inks loaded with ceramic hollow spheres, which are biocemented by the precipitation of calcium carbonate induced by ureolytic bacteria. Electron microscopy, thermogravimetric analysis and mechanical tests are performed to study the kinetics of the biocementation process and its effect on the calcification and mechanical properties of extruded and printed samples. Hierarchical porous ceramics with a grid‐like architecture and filament sizes in the order of one millimeter are effectively biocemented at ambient temperature after 2 days of calcification. The calcified structures display higher mechanical efficiency than previously reported monoliths of comparable porosity, thus demonstrating the potential of 3D printing and bacteria‐driven biocementation for the low‐temperature fabrication of hierarchical porous ceramics. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the association between net mechanical efficiency (NME) and body composition and glycemic profile, in middle-aged (38.3 ± 14.3 years) participants from the Quebec Family Study (QFS). Analyses were completed on a sample of 605 participants (271 males and 334 females) who performed a submaximal exercise test on an ergometer consisting of three consecutive 6-min workloads at increasing intensity during which respiratory gas exchange was assessed. The calculation of NME [power output/ (vO2-vO2seated before exercise)] was based on the values of the last 3 min of the first workload at a targeted power output of 30 W. Correlations between NME and dependent variables were computed separately in males and females. Associations between NME and body composition and glucose–insulin variables were assessed by comparing groups of subjects categorized in sex-specific tertiles of NME after adjustments for age. Significant negative correlations were observed between NME and body composition and glycemic profile in both sexes. Comparison across tertiles showed that individuals with high NME displayed more favorable adiposity and glycemic profiles. These differences remained significant after further adjustments for participation in vigorous physical activity, cardiorespiratory fitness, and mean exercise respiratory exchange ratio whereas most differences in glucose–insulin variables became non-significant after further adjustment for percent body fat. QFS familial data indicate that the heritability of NME reaches about 30%. In conclusion, the results of this study show that beyond aerobic fitness and physical activity-participation, mechanical efficiency is an additional activity-related variable that is independently associated with variations in body composition and glycemic profile. [ABSTRACT FROM AUTHOR]

Lattice structures are widely used in load-bearing and energy-absorption applications for their lightweight, high specific stiffness, high specific strength and excellent energy-absorption. A novel hybrid lattice cell that combining octet cell and body-centered cube cell was proposed, and quasi-static compression experiments and finite element simulations were performed to investigate their energy-absorption characteristic and deformation mechanisms. The effects of the relative density, configuration of cell and component ratio sub-cell on the compression responses were also explored. The results showed that hybrid lattice improves compression modulus and yield strength by 10% and 16% maximally, respectively, and the energy-absorption of enhancement is 20% higher than the conventional lattices. In addition, the hybrid lattice can significantly alleviate the stress softening. By increasing the volume ratio of body centered cubic in the hybrid lattice structures, the energy-absorption can be improved. Under dynamic loading, the proposed hybrid lattice structures displayed outstanding normalized yield strength, which is superior to majority of porous structures. Inspired by the precipitation hardening mechanisms used in metallurgy to design high-performance alloys, two dual-phase lattices are developed. The quasi-static compression of dual-phase lattices shows three stages plateau stress and has a higher third stage than that of traditional dual-phase lattices. These findings provided design strategy for lightweight structure. [ABSTRACT FROM AUTHOR]

Based on the self-developed hydraulic variable valve mechanism of four-cylinder engine, this paper proposes a variable displacement valve control strategy based on the VOC-CDA mode of electro-hydraulic. The variation rules of in-cylinder pressure, oxygen mass fraction in exhaust gas, torque fluctuation and other parameters in the process of cylinder deactivation cycle and working mode conversion are analyzed, and the control parameters of inlet and exhaust valves at the best cylinder deactivation time are optimized. The energy saving mechanism of variable displacement technology is analyzed from the aspects of indicated thermal efficiency, mechanical efficiency and effective thermal efficiency. Based on the optimal intake and exhaust valve closing time, the engine can improve the fuel economy by 8.7% at medium and small loads. It provides a certain design reference for the development of variable displacement engine based on hydraulic variable valve mechanism. [ABSTRACT FROM AUTHOR]

Harvesting equipment is closely related to the harvesting quality and efficiency, particularly for the Chinese wolfberry. In this study, a method of arrayed vibration unit was proposed in the mechanized harvesting equipment, according to the agronomy of hedgerow type Chinese wolfberry bilateral fruit hanging planting. The structural design of the arrayed vibration components and the fruit receiving platform was carried out, and then the walking, conveying, sorting and stability analysis of the whole machine were carried out. The arrayed layout parameters of different stubble numbers of Chinese wolfberry Xia Guo in Ningxia were measured. A series of significant paramerers were conducted to determine the vibration unit structure, vibration frequency, vibration angle, the crawler assembly, the transmission structure and driving of horizontal and vertical conveyor belts, the position of fruit receiving basket and lifting conveyor belt and the wind speed of debris sorting. Furthermore, the driving stability of the whole machine was verified on the slope. After that, the performance tests of the whole machine were carried out to evaluate the feasibility and efficiency of the mechanism, according to the test conditions and walking, harvesting and sorting. The selected indicators and the results showed that the maximum running speed of the whole chassis in all conditions was up to 0.252 m/s, the minimum turning radius was limited in 1.86 m, the maximum slope was 32°, the maximum crossing ditch width was no more than 0.5 m, and the maximum crossing step height was 11 cm. All the indicators were verified for the better walking performance, compared with the traditional. The harvesting object was taken as the sixth crop of Chinese wolfberry in Xiaguo, Ningxia Ningqi No.1. The amplitude was fixed at 15 mm. The optimum operating conditions were as follows: the driving speed was 1 300 r/min, vibration time was 5 s, the picking efficiency of mature Chinese wolfberry was 4 037 fruits per minute, the net picking rate of mature Chinese wolfberry was 88.95%, the damage rate of mature Chinese wolfberry was 3.64%, the damage rate of dried mature Chinese wolfberry was 4.17%, the comprehensive false picking rate of immature fruits, olives and flowers was 3.80%, and the efficiency ratio of mechanical picking to human picking was 26.91. All the performance indicators were presented that the Chinese wolfberry fruit of mechanized picking was fully met the requirements of its commercial processing. In addition, the wind speed was determined to be at least 5 m/s, which was beneficial to the separation of fruits and leaves. [ABSTRACT FROM AUTHOR]

Rolling bearings are vital components in rotating machinery, and their reliable operation is crucial for maintaining the stability and efficiency of mechanical systems. However, fault detection in rolling bearings is often hindered by noise interference in complex industrial environments. To overcome this challenge, this paper presents a novel fault diagnosis method for rolling bearings, combining Convolutional Neural Networks (CNNs) and Gated Recurrent Units (GRUs), integrated with the envelope analysis and adaptive mean filtering techniques. Initially, envelope analysis and adaptive mean filtering are applied to suppress random noise in the bearing signals, thereby enhancing the visibility of fault features. Subsequently, a deep learning model that combines a CNN and a GRU is developed: the CNN extracts spatial features, while the GRU captures the temporal dependencies between these features. The integration of the CNN and GRU significantly improves the accuracy and robustness of fault diagnosis. The proposed method is validated using the CWRU dataset, with the experimental results achieving an average accuracy of 99.25%. Additionally, the method is compared to four classical fault diagnosis models, demonstrating superior performance in terms of both diagnostic accuracy and generalization ability. The results, supported by various visualization techniques, show that the proposed approach effectively addresses the challenges of fault detection in rolling bearings under complex industrial conditions. [ABSTRACT FROM AUTHOR]

Multi‐component copolymerized donors (MCDs) hold great promise for improving both the efficiency and mechanical robustness of flexible organic solar cells (f‐OSCs) owing to their facile molecular tunability and advantageous one‐pot copolymerization. However, despite the excellent crystallinity imparted by their highly conjugated polymer backbone, MCDs often struggle to retain photovoltaic performance under large external deformations, limiting their applicability in wearable devices. Herein, we developed a novel series of flexible linker‐sequential block MCDs (Fs‐MCDs), specifically PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTB, PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTH, and PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTD, by precisely incorporating flexible functional groups into the conjugated polymer skeleton. This design strategy introduced highly effective tensile active sites, resulting in remarkable mechanical durability, with PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTD achieving crack‐onset strain (COS) values of 49.88 % in pristine films and 31.29 % in blends. The nearly 50 % COS in pristine films represents one of the highest values reported for Fs‐MCD‐based OSCs, marking a significant milestone in advancing f‐OSC. Additionally, PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTD demonstrated excellent photovoltaic performance, with efficiencies of 18.09 % in rigid binary and 19.05 % in ternary, as well as 16.63 % in flexible OSCs. It also showed impressive device stability in invert OSC (T80=9,078 h). This unique molecular design strategy provides a promising avenue for synergistically improving the photovoltaic performance, mechanical properties, and device stability of f‐OSCs. [ABSTRACT FROM AUTHOR]

Long‐term access to undersea information is of critical importance for undersea sensing. However, the paramount challenge in marine wearable technology lies in achieving durable and stable adhesion, coupled with biocompatibility, for devices submerged in the saline conditions of the ocean. Here, a self‐healing, seawater‐resistant hydrogel is reported that exhibits robust adhesion to diverse biotic and abiotic surfaces. Remarkably, the presented hydrogel is augmented with octopus sucker‐inspired microstructures, a feature that markedly improves its capability of organism adhesion underwater. The hydrogel exhibits robust mechanical properties in water, with over 20‐fold elongation in a fully swollen state, and a mechanical healing efficiency exceeding 90% after healing for 30 min. The hydrogel is applied toward several representative undersea scenes. Specifically, the hydrogels equipped with flexible pressure sensors are reliably affixed to fish and turtles for sensing hydraulic pressure for more than 20 days, while the hydrogels featuring a compact camera are mounted on corals and crabs for constant monitoring of surroundings. Furthermore, the hydrogel is molded into a mesh structure for integrating multiple sensors, functioning as multi‐node marine wearable platforms. The underwater hydrogel, with its broad applicability, introduces an approach to real‐time undersea monitoring and non‐invasive marine life internet construction. [ABSTRACT FROM AUTHOR]

Fault classification of mechanical equipment is a vital issue in modern industrial production. Mechanical equipment typically relies on multiple sensors to collect the operational data, which is represented as multivariate time-series data. However, existing methods for analyzing mechanical faults often overlook the causal relationships between sensors and struggle with the scarcity of labeled training samples. To address these challenges, we propose a graph neural network model leveraging sensor causality and meta-learning for mechanical fault classification (SCML-GNN). Specifically, we use transfer entropy to represent multivariate time-series data as a graph, with each sensor as a node and their causal relationships as edges. We then extract the node features using temporal convolutional layers and apply a graph neural network to learn the low-dimensional features. Additionally, graph pooling methods are used to obtain global embeddings. To further tackle the issue of limited labeled training samples, we introduce a metric-based class prototype attention mechanism within SCML-GNN. Extensive experiments conducted on three real-world mechanical equipment datasets demonstrate the superior effectiveness and efficiency of SCML-GNN in mechanical fault classification compared to the other existing methods. [ABSTRACT FROM AUTHOR]

AbstractTo address the conflict between load conditions and material utilization, natural materials have evolved unique structural strategies exhibiting high mechanical efficiency. Building on natural hierarchy and gradient strategies, the current study constructs hybrid hierarchical gradient honeycombs (HHGH), aiming to enhance crashworthiness. Subsequently, the impact of each strategy on the crashworthiness performance is thoroughly investigated. Ultimately, the configuration of the HHGH was optimized by RBF and NSGA-II. The results indicate that the hybridization of various enhancement strategies significantly improves the crashworthiness. Quantitatively, the SEA of the HHGH is 2.91 times that of the corresponding regular honeycomb, with similar PCF. [ABSTRACT FROM AUTHOR]

This research investigates the optimization of 3D printer settings to enhance the mechanical properties of polylactic acid (PLA) printed parts. A fundamental aspect of this study involves the design and development of a 3D printer capable of accommodating varied printing parameters. The parameters under consideration include extruder temperature, layer height, print speed, and infill density. Through experimentation, the tensile strength and the bending strength of PLA material are systematically evaluated against these printing parameters. The results unveil significant correlations between printing parameters and mechanical properties. It is observed that increasing the extruder temperature up to 220°C increases the material strength, beyond which a decline is evident due to overextrusion and material degradation. Conversely, increasing the layer height leads to a reduction in strength, attributed to diminished layer adhesion and structural integrity. Moreover, decreasing print speed is found to enhance strength at the expense of increased print time, suggesting a trade‐off between efficiency and mechanical performance. Furthermore, the study demonstrates that augmenting infill density contributes to a notable increase in material strength, underscoring the importance of internal reinforcement in enhancing structural integrity. These findings provide valuable insights into the optimization of 3D printing processes for PLA materials, offering guidelines for achieving superior mechanical properties through precise calibration of printing parameters. [ABSTRACT FROM AUTHOR]

To establish a universal and convenient mathematical model for predicting static and dynamic performance of composite sandwich structures, a novel three-dimensional equivalent homogenized model (3D-EHM) is proposed based on variational asymptotic method. The multiscale mechanical analysis of composite hexagonal and re-entrant honeycomb sandwich structures is conducted by 3D-EHM, enabling reasonable transmission of mechanical information at different scales and facilitating accurate predictions of mechanical responses in sandwich structures. The comparison analysis with 3D printing experimental results and 3D finite element model results demonstrates that the 3D-EHM exhibits remarkable precision and computational efficiency in forecasting static displacement distributions and higher-order vibration modes, eliminating the need for time-consuming and expensive experiments. Moreover, the effects of the ply angle of the face sheet and core geometric parameters on the effective properties of composite hexagonal honeycomb sandwich structures are systematically investigated. In summary, 3D-EHM is an effective applied mathematical model for designing and analyzing composite sandwich structures, fully combining the systematicity of variational methods and the asymptotic convergence of asymptotic methods. • A novel three-dimensional equivalent homogenized model (3D-EHM) is proposed. • Calculation accuracy and efficiency in predicting mechanical response are high. • Intrinsic connection between microstructure and macroscopic properties is captured. • 3D-EHM facilitates the tailoring and optimization of the sandwich structure. [ABSTRACT FROM AUTHOR]

Supramolecular gels (SGs) consisted of noncovalent cross-linking network structures are fascinating due to their efficient energy dissipation and reversible self-healing properties. However, it is unknown how the noncovalent interactions alter the macroscopic self-healing and mechanical properties of SGs. Herein, the peculiar nature of SGs manufactured by combining covalent and noncovalent (host–guest inclusion of β-cyclodextrin and C16 hydrophobic chain) cross-linking structures was studied and compared with covalent cross-linking preformed particle gels. The macroscopic self-healing behaviors, rheology, mechanical tensile properties, as well as the tunable mechanisms of self-healing were explored by visual inspection, rheological, and atomic force microscopy probing methods. The results show that the SGs exhibit excellent self-healing efficiency and mechanical strength after interfacial cutting. Moreover, the SGs exhibited excellent mechanical tensile properties, including loading–unloading, successive loading–unloading, and recovery loading–unloading tensile performances. Notably, the macroscopic self-healing of SGs has good tunability by changing the covalent and noncovalent crosslinker contents and salt contents. This peculiar phenomenon is attributed to certain host–guest inclusion forces (4.7 and 0.3 nN) between different SGs under the distilled and high-salinity water conditions, respectively. This study is beneficial for the development of stimuli–response supramolecular gels in different applications, such as oil recovery in fractured reservoirs. [ABSTRACT FROM AUTHOR]

E-waste toner (EWT), which is produced in large quantities by modern industries, has the potential to be utilized as a bitumen modifier to improve engineering properties and save costs. The current study focuses on exploring the optimization of EWT content to identify the most optimal proportions for achieving desirable levels of mechanical properties. This study also examined the effects of E-waste toner contents ranging from 0% to 30% on the fresh consistency of toner-modified and unmodified binder. The study utilized a central composite design (CCD) together with the response surface methodology (RSM) to optimize the mix design variables, specifically the binder-toner ratio (BT) and mixing efficiency ratio (MER). The objective of this study was to examine the combined effects of these variables on the mechanical characteristics of EWT-modified asphalt mixtures. The mechanical responses were obtained through the performance of four responses such as Marshall stability (MS), Marshall flow (MF), indirect tensile strength (ITS), and stiffness tests. The findings suggest that the combined interaction of BT and MER ratios has an impact on their mechanical characteristics. However, the BT ratios had a significant impact on the volumetric attributes compared to MER. The RSM-based prediction models had an R-square over 0.86 across each response. This demonstrates that the inclusion of BT and MER ratios were accountable for a minimum of 86% of the alterations in the mechanical characteristics of EWT-modified asphalt. The multi-objective optimization analysis determined that the optimal proportions for the EWT-modified asphalt, in order to obtain the ideal consistency, were 0.249 ratio of BT and 1.63 ratio of MER with a desirability value of 0.97. Overall, it was found that RSM is a reliable technique for precisely forecasting the mechanical properties of EWT-modified asphalt, including BT and MER ratios. [ABSTRACT FROM AUTHOR]

A nanosecond laser is used to weld 35 μm thickness copper and 100 μm thickness aluminum foil. The influence of nanosecond laser scanning paths on the weld formation, microstructure and mechanical properties is investigated. The results show that the weld formation of the polygonal nanosecond laser scanning path presents obvious anisotropy. The microstructures of the nanosecond laser welded joints of the two scanning paths are similar, mainly composed of the columnar γ-Cu9Al4, blocky θ-CuAl2 phase and reticular θ-CuAl2 + α-Al eutectic phase. During the tension-shear test of the Al/Cu nanosecond laser welded joint, stress concentration and crack initiation begin to occur along the brittle intermetallic compounds (IMCs) of massive θ-CuAl2 at the interface, and then, the crack propagates along the reticular θ-CuAl2 and finally fracture failure occurs. Considering the welding efficiency and mechanical properties, a spiral scanning path is recommended. [ABSTRACT FROM AUTHOR]

This study investigates the cytotoxicity of various orthodontic archwires, which are essential in directing tooth movement through biomechanical forces. With advancements in material science, different archwire materials have been developed to balance mechanical performance with aesthetic and biological considerations. The study focuses on evaluating the biocompatibility and mechanical properties of stainless steel, nickel–titanium, and chromium–cobalt archwires, particularly their cytotoxic effects on oral cavity cells. In vitro cell culture experiments with fibroblasts, combined with scanning electron microscopy (SEM) analysis, were conducted to assess cell viability and morphology. The results revealed significant differences in cytotoxicity, with copper wires showing high toxicity and causing extensive cell death, while nickel–titanium and chromium–cobalt wires supported better cell viability and healthier cell morphology. These findings highlight the importance of selecting archwire materials that ensure mechanical efficiency without compromising cellular health, emphasizing the need for ongoing assessment of material biocompatibility in the oral environment. [ABSTRACT FROM AUTHOR]

Fluid‐driven artificial muscles exhibit a behavior similar to biological muscles which makes them attractive as soft actuators for wearable assistive robots. However, state‐of‐the‐art fluidic systems typically face challenges to meet the multifaceted needs of soft wearable robots. First, soft robots are usually constrained to tethered pressure sources or bulky configurations based on flow control valves for delivery and control of high assistive forces. Second, although some soft robots exhibit untethered operation, they are significantly limited to low force capabilities. Herein, an electrohydraulic actuation system that enables both untethered and high‐force soft wearable robots is presented. This solution is achieved through a twofold design approach. First, a simplified direct‐drive actuation paradigm composed of motor, gear‐pump, and hydraulic artificial muscle (HAM) is proposed, which allows for a compact and lightweight (1.6 kg) valveless design. Second, a fluidic engine composed of a high‐torque motor with a custom‐designed gear pump is created, which is capable of generating high pressure (up to 0.75 MPa) to drive the HAM in delivering high forces (580 N). Experimental results show that the developed fluidic engine significantly outperforms state‐of‐the‐art systems in mechanical efficiency and suggest opportunities for effective deployment in soft wearable robots for human assistance. [ABSTRACT FROM AUTHOR]

Biological composites such as bone, nacre, and teeth show excellent mechanical efficiency because of the incorporation of biominerals into the organic matrix at the nanoscale, leading to hierarchical composite structures. Adding a large volume of ceramic nanoparticles into an organic molecular network uniformly has been a challenge in engineering applications. However, in natural organisms, biominerals grow inside organic fibers, such as chitin and collagen, forming perfect ceramic/polymer composites spontaneously via biomineralization processes. Inspired from these processes, the in situ growth of calcium carbonate nanoparticles inside the chitosan network to form ceramic composites was proposed in the current work. The crystal growth of CaCO3 nanoparticles in the chitosan matrix as a function of time was investigated. A weight percentage of ~35 wt% CaCO3 composite was realized, resembling the high weight percentage of mineral phase in bones. Scanning and transmission electron microscopy indicated the integration of CaCO3 nanocrystals with chitosan macromolecules. By growing CaCO3 minerals inside the chitosan matrix, the elastic modulus and tensile strength increases by ~110% and ~90%, respectively. The in situ crystal growth strategy was also demonstrated in organic frameworks prepared via 3D printing, indicating the potential of fabricating ceramic/polymer composites with complicated structures, and further applications in tissue engineering. [ABSTRACT FROM AUTHOR]

In terms of the interplay between manufacturing cost and quality during the molding of fiber reinforced thermosetting composites, this study proposes a multi‐scale collaborative optimization strategy aimed at shortening molding time and reducing the diminishing defects generated during the process. Macro‐scale thermochemical and micro‐scale thermomechanical calculations are conducted on the composite molding to analyze the origins of temperature gradients and residual stresses. Then, the curing cycle, temperature gradient in the macro‐scale model, and residual stresses in the micro‐scale model are optimized by combining finite element analysis with the Non‐dominated Sorting Genetic Algorithm II. Several curing processes within the Pareto front were selected, and their impact on compressive performance was assessed through experimental analysis. Compared to the standard curing process (SCP), the optimal curing process exhibited a 41.4% reduction in maximum temperature gradient (∆Tmax), a 25.2% decrease in effective residual stress σ¯, and a 20.0% increase in compressive strength. Multi‐scale collaborative optimization strategies are integral to the advancement of production and application of fiber‐reinforced thermoset composites. Multi‐scale collaborative optimization strategies are integral to the advancement of production and application of fiber‐reinforced thermoset composites. Highlights: Investigated of interactions among components in composites molding.Optimization of composite molding process with Non‐dominated Sorting Genetic Algorithm II and finite element.Examined the impact of composite molding process on compressive performance. [ABSTRACT FROM AUTHOR]

Biomimetic actuation technologies with high muscle strokes, cycle rates, and work capacities are necessary for robotic systems. We present a muscle type that operates based on changes in muscle stiffness caused by volume expansion. This muscle is created by coiling a mechanically strong braid, in which an elastomer hollow tube is adhesively attached inside. We show that the muscle reversibly contracts by 47.3% when driven by an oscillating input air pressure of 120 kilopascals at 10 Hz. It generates a maximum power density of 3.0 W/g and demonstrates a mechanical contractile efficiency of 74%. The muscle's low-pressure operation allowed for portable, thermal pneumatical actuation. Moreover, the muscle demonstrated bipolar actuation, wherein internal pressure leads to muscle length expansion if the initial muscle length is compressed and contraction if the muscle is not compressed. Modeling indicates that muscle expansion significantly alters its stiffness, which causes muscle actuation. We demonstrate the utility of BCMs for fast running and climbing robots. [ABSTRACT FROM AUTHOR]

Concurrently achieving high efficiency, mechanical robustness and thermal stability is critical for the commercialization of all‐polymer solar cells (APSCs). However, APSCs usually demonstrate complicated morphology, primarily attributed to the polymer chain entanglement which has a detrimental effect on their fill factors (FF) and morphology stability. To address these concerns, an end‐group extended polymer acceptor, PY‐NFT, was synthesized and studied. The morphology analysis showed a tightly ordered molecular packing mode and a favorable phase separation was formed. The PM6 : PY‐NFT‐based device achieved an exceptional PCE of 19.12 % (certified as 18.45 %), outperforming the control PM6 : PY‐FT devices (17.14 %). This significant improvement highlights the record‐high PCE for binary APSCs. The thermal aging study revealed that the PM6 : PY‐NFT blend exhibited excellent morphological stability, thereby achieving superior device stability, retaining 90 % of initial efficiency after enduring thermal stress (65 °C) for 1500 hours. More importantly, the PM6 : PY‐NFT blend film exhibited outstanding mechanical ductility with a crack onset strain of 24.1 %. Overall, rational chemical structure innovation, especially the conjugation extension strategy to trigger appropriate phase separation and stable morphology, is the key to achieving high efficiency, improved thermal stability and robust mechanical stability of APSCs. [ABSTRACT FROM AUTHOR]

Bio-mediated methods, such as microbially induced carbonate precipitation, are promising techniques for soil stabilisation. However, uncertainty about the spatial distribution of the minerals formed and the mechanical improvements impedes bio-mediated methods from being translated widely into practice. To bolster confidence in bio-treatment, non-destructive characterisation is desired. Seismic methods offer the possibility to monitor the effectiveness and mechanical efficiency of bio-treatment both in the laboratory and in the field. To aid the interpretation of shear wave velocity measurements, this study uses the discrete element method to examine the small-strain stiffness of bio-cemented sands. Bio-cemented specimens with different characteristics, including properties of the host sand (void ratio, uniformity of particle size distribution) and properties of the precipitated minerals (distribution pattern, content, Young's modulus), are modelled and subjected to static probing. The mechanisms affecting the small-strain properties of cemented soils are investigated from microscopic observations. The results identify two mechanisms controlling the mechanical reinforcement associated with bio-cementation, namely the number of effective bonds and the ability of a single bond to improve stiffness. The results show that the dominant mechanism varies with the properties of the host sand. These results support the use of seismic measurements to assess the mechanical efficiency and effectiveness of bio-mediated treatment. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to examine the environmental effects of plastic waste on the atmosphere and its implications for disaster waste management. It focuses on using ammonia, pyrolyzed plastic oil and the effectiveness of alumina nanoparticles as a catalyst. Design/methodology/approach: The research explores different combinations of conventional diesel and nano Al2O3 derived from pyrolyzed plastic oil (ranging from P10 to P40). Critical performance metrics evaluated include brake mean effective pressure (BMEP), brake specific fuel consumption, brake thermal efficiency and emissions of CO2, CO and NOx. The study specifically investigates the impact of adding 50 ppm of Al2O3 nanoparticles to these blends. Findings: The findings indicate that using blended fuels with nanoadditives significantly lowers pollution. Specifically, the P30 blend with 50 ppm of Al2O3 nanoparticles greatly reduced CO emissions. Additionally, the same blend reduced NOx emissions and CO2 emissions. The P30 mix showed improved BMEP and brake thermal efficiency due to its density, calorific value and viscosity (6.3 bar). The P30 blend exhibited higher thermal efficiency due to decreased heat loss, whereas conventional diesel demonstrated the best mechanical efficiency due to its longer ignition delay. Originality/value: This study highlights the potential of using Al2O3 nanoparticles and pyrolyzed plastic oil to reduce emissions and enhance the performance of internal combustion engines. It underscores the environmental benefits and implications for disaster waste management by converting plastic waste into useful resources and reducing air pollution. [ABSTRACT FROM AUTHOR]

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An investigation of the interaction between multidimensional nano-additives and tribofilms is crucial for enhancing mechanical efficiency, extending equipment lifespan, and reducing environmental impacts. Improved tribofilm performance is obtained via several mechanisms: filling surface defects with 0D nano-additives, directional lubrication for 1D nano-additives, interlayer slippage for 2D nano-additives, and improved film durability for 3D nano-additives. Under dry lubrication, the formation of tribofilms via mechanical mixing is influenced by material hardness, surface roughness, and frictional conditions, with their thicknesses increasing by 20–30% under high loading. Conversely, liquid-lubricated films result from the physical adsorption and chemical reactions of the lubricants, with extremely high pressure additives reducing the friction coefficient by 30–50% at high pressure. A greater understanding of these mechanisms is beneficial for optimizing industrial technologies and developing efficient, eco-friendly lubrication systems. [ABSTRACT FROM AUTHOR]

This study aims to analyze the effect of 70-30 Cu-Ni filler metal on mechanical and microstructural properties of Al 2024 and stainless steel 304 hybrid joints fabricated through the gas tungsten arc welding technique. The mechanical properties, i.e., tensile strength and microhardness, of Al-SS joints have been analyzed and evaluated through joint interfacial microstructure analysis. The optimum tensile strength (155.746 MPa) has been obtained at welding current ranges between 75 and 80 A, welding speed of 110–115 mm/min, and gas flow rate of 9.75-10 L/min, whereas maximum microhardness (300 HV) at welding speed of 115-120 mm/min, welding current of 70-75 A, and gas flow rate of 9.5-10 L/min. The fine equiaxed dendrites at the interface of the aluminum weld zone and the thin interfacial layer at the SS304 weld zone interface contributed to the higher tensile strength. Scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction reveal the ductile CuAl, NiAl3, and NiAl phases instead of Fe-Al brittle phase, improving hybrid bonding between Al 2024 and SS 304. The dimples and tear ridges microstructure have been observed for high-strength joint, while cracks and cavities on the fracture surface indicate its brittleness and low strength (102 MPa). [ABSTRACT FROM AUTHOR]

Abstract\nIMPLICATIONS FOR REHABILITATIONThe gross mechanical efficiency of the manual wheelchair propulsion movement is particularly low compared to other movements. The energy losses in the manual wheelchair propulsion movement are partly due to energy losses associated with the wheelchair, and especially to the rolling resistance of the wheels. The distribution of mass between the front rear wheels and the caster wheels has a significant impact on the rolling resistance. The study of the caster wheels cannot therefore be neglected due to their involvement in rolling resistance. Thus, this study aimed to evaluate the power dissipated due to rolling resistance by different caster wheels, at different speeds and under different loadings on various terrains. Four caster wheels of different shapes, diameters, and materials were tested on two surfaces representative of indoor sports surfaces at four different speeds and under four loadings. The results showed a minimal dissipated power of 0.4±0.2W for the skate caster, on the parquet, at 0.5 m/s and under a loading of 50 N. The maximal mean power dissipated was 43.3±27.6W still for the skate caster, but on the Taraflex, at 1.5 m/s and under loading of 200 N. The power dissipated on the parquet was lower than the one on the Taraflex. The Spherical and Omniwheel caster wheels dissipated less power than the two other casters. This study showed that caster wheels cannot be neglected in the assessment of gross mechanical efficiency, particularly in light of the power dissipated by athletes during propulsion.Highlights the importance of choosing the right front casters depending on the conditions of use of the manual wheelchair.First study to evaluate power dissipation due to rolling resistance in front casters during wheelchair propulsion.Shows that a Taraflex type floor is not suitable for wheelchair sports performance and injury prevention purposes and lower musculoskeletal constraints with equivalent performance.Highlights the importance of choosing the right front casters depending on the conditions of use of the manual wheelchair.First study to evaluate power dissipation due to rolling resistance in front casters during wheelchair propulsion.Shows that a Taraflex type floor is not suitable for wheelchair sports performance and injury prevention purposes and lower musculoskeletal constraints with equivalent performance. [ABSTRACT FROM AUTHOR]

Polymer-based self-lubricating materials are designed to improve the efficiency and reliability of mechanical systems, reducing energy consumption and material loss. Herein, inspired by the texture of the smooth leaf surface, the polyether ether ketone was first subjected to a sulfonation treatment before the plant texture was introduced to the surface of the sulfonated polyether ether ketone (SPEEK) films. The optical microscopy results indicate the successful construction of different bionic textures on SPEEK film surface. Based on the reduction in the contact area between the friction pairs, and the accommodation of abrasive debris by the uneven bionic textures, the tribological performance of SPEEK films under dry friction conditions shows unique advantages. Additionally, the wear morphology and self-lubrication mechanism of bionic textured films were investigated by 3D profilometry, SEM, and XPS. The results show that under the effect of frictional heat and frictional force, the bionic texture morphology changes to fish scale, which reduces the resistance to friction, resulting in a lower friction coefficient and wear rate. This strategy of constructing bionic textures on functional polymer surfaces using a facile process provides a reference for exploring novel self-lubricating materials. [ABSTRACT FROM AUTHOR]

DNA hydrogels hold significant promise for biomedical applications and can be synthesized through enzymatic Rolling Circle Amplification (RCA). Due to the exploratory nature of this emerging field, standardized RCA protocols specifying the impact of reaction parameters are currently lacking. This study varied template sequences and reagent concentrations, evaluating RCA synthesis efficiency and hydrogel mechanical properties through quantitative PCR (qPCR) and indentation measurements, respectively. Primer concentration and stabilizing additives showed minimal impact on RCA efficiency, while changes in polymerase and nucleotide concentrations had a stronger effect. Concentration of the circular template exerted the greatest influence on RCA productivity. An exponential correlation between hydrogel viscosity and DNA amplicon concentration was observed, with nucleobase sequence significantly affecting both amplification efficiency and material properties, particularly through secondary structures. This study suggests that combining high‐throughput experimental methods with structural folding prediction offers a viable approach for systematically establishing structure‐property relationships, aiding the rational design of DNA hydrogel material systems. [ABSTRACT FROM AUTHOR]

This study aimed to improve the design of an automatically controlled sail wind power station (SWPS). The peculiarity of the considered SWPS design is that its working body (WB) is rigidly connected to the upper platform of a Sholkor parallel manipulator that has six degrees of freedom. Six actuators connect the manipulator's upper platform to the fixed lower platform. Each actuator is multifunctional and converts mechanical energy from wind action into electrical energy while controlling the WB's movements. This wind energy conversion, by which the SWPS's structural efficiency is evaluated, largely depends on the actuator's coefficient of performance (CP). To meet the study objective, a prototype actuator was experimentally investigated to establish its efficiency. For this, a new experimental methodology was proposed, which involved sequentially experimenting on wind characteristics to obtain data, establishing a database, processing and preparing the initial data, and conducting a force analysis of the SWPS. Based thereon, the predicted power of the input load on the actuators was determined using Mathcad software. In the experimental setup, this predicted power was used as the actuator's input, and the experimental value of the generated electrical energy (the output power) gave the actuator prototype's efficiency. The actuator's average experimental CP was η― = 0.56−0.58, which demonstrates that this geometry's dimensions and parameters are acceptable. The results of the study will be used to improve the design. The article emphasizes the potential of SWPSs for producing wind energy. [ABSTRACT FROM AUTHOR]