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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 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]

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]

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]

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 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]

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]

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]

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]

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]

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]

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]

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]

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]

There has been an intense surge in interest in the search for alternative sources of petroleum fuels in the modern world as a result of the inflation of fuel prices and the historic supply gap. When compared to petroleum fuels, biodiesel is becoming an increasingly valuable option due to the fact that it produces less emissions and provides the almost same amount of energy. In point of fact, the prime aim of this work is to explore the possibility of utilizing biodiesel derived from lemongrass oil and including dibutyl ether as an additive for the test diesel engine operating on varied compression ratios. The findings showed that the best operating settings are a 17.5 compression ratio with a blend of 30% biodiesel and 70% diesel fuel. At greater loads, brake thermal efficiency is lower than that of diesel engines. Lower loads result in lower specific fuel usage. Mechanical efficiency at higher loads is highest in the B30 blend, but emission metrics such as CO, CO2, HC, and NOx were reduced with the inclusion of an additive, though HC rose with higher loads of lemongrass oil biodiesel blends. When compared to the B30 biodiesel blend with various composition additives, the B30 + 4% additive has the highest efficiency at the fourth load in terms of both brake power and mechanical efficiency. [ABSTRACT FROM AUTHOR]

As a critical component in mechanical systems, the operational status of rolling bearings plays a pivotal role in ensuring the stability and safety of the entire system. However, in practical applications, the fault diagnosis of rolling bearings often encounters limitations due to the constraint of sample size, leading to suboptimal diagnostic accuracy. This article proposes a rolling bearing fault diagnosis method based on an improved denoising diffusion probability model (DDPM) to address this issue. The practical value of this research lies in its ability to address the limitation of small sample sizes in rolling bearing fault diagnosis. By leveraging DDPM to generate one-dimensional vibration data, the proposed method significantly enriches the datasets and consequently enhances the generalization capability of the diagnostic model. During the model training process, we innovatively introduce the feature differences between the original vibration data and the predicted vibration data generated based on prediction noise into the loss function, making the generated data more directional and targeted. In addition, this article adopts a one-dimensional convolutional neural network (1D-CNN) to construct a fault diagnosis model to more accurately extract and focus on key feature information related to faults. The experimental results show that this method can effectively improve the accuracy and reliability of rolling bearing fault diagnosis, providing new ideas and methods for fault detection and prevention in industrial applications. This advancement in diagnostic technology has the potential to significantly reduce the risk of system failures, enhance operational efficiency, and lower maintenance costs, thus contributing significantly to the safety and efficiency of mechanical systems. [ABSTRACT FROM AUTHOR]

In this study, a novel multifunctional film known as susceptor, containing silver nanoparticles, was proposed to improve the induction welding performance of unidirectional carbon fiber-reinforced polyetherketoneketone (CF/PEKK) thermoplastic composites. A group of Ag/PEKK films was synthesized with different amounts of silver nanoparticles. Good thermal performance was obtained, including the maximum temperature and thermal growth time constant, leading to the selection of films with 60 wt.% and 70 wt.% silver nanoparticles. In addition, the mechanical performance was evaluated for single-lap joints fabricated with the selected films and stainless-steel mesh. Specifically, the highest interlaminar shear strength and single-lap shear strength of 25.2 MPa and 20.9 MPa, respectively, were achieved with a susceptor containing 60 wt.% silver nanoparticles. The mechanism of these increases in thermal and mechanical performance is discussed using numerical and experimental methods (non-destructive test and optical microscope observation). In conclusion, the multifunctional heating film incorporated into the adhesive can improve the thermal and mechanical efficiency of single-lap joints of thermoplastic composites fabricated using the induction welding method. [ABSTRACT FROM AUTHOR]

Current trends in agricultural intensification lead to degraded grasslands, requiring their restoration through native species reintroduction. Various techniques are available for harvesting seeds from donor sites. However, little is known about their performance in South American C3/C4 mixed grasslands, where studies are scarce. Their particular species composition and phenology, with different flowering periods, require specific harvest strategies. We evaluated mechanical seed harvest in a northern Uruguay grassland, part of Río de la Plata grasslands. Performance of two mechanical harvest methods (seed‐stripper and dry hay) was compared in two harvest seasons (late‐spring and mid‐summer). The evaluation considered the quantity and identity of harvested seeds, and their germination in a greenhouse. Hand collections were made to assess standing seed yield. For each seed mixture, efficiency of mechanical harvests (number of seeds and seedlings compared to hand collection), proportion of germinated seeds, species transfer relative to donor site, and composition were calculated. Results revealed trade‐offs between harvests: seed‐stripper in late‐spring presented low seed collection efficiency (2% for seeds, 5% for seedlings) and species richness (43% transfer), but high seed germination (64%), showing selectivity toward winter species; seed‐stripper in mid‐summer and dry hay in both seasons showed high seed collection efficiency (42–154% for seeds, 26–50% for seedlings) and species richness (65–80% transfer), resembling donor site, albeit lower seed germination (9–20%). Seed‐stripper performance varied between seasons, while dry hay remained consistently effective. These results are pioneering for grassland restoration in Uruguay, encouraging future studies to focus on establishment in the field. [ABSTRACT FROM AUTHOR]

In the development of composite solid propellants, maintaining energy-release efficiency while enhancing the mechanical properties of the propellants presents a significant challenge. Optimizing the interfacial relationships among various propellant components can potentially improve both the mechanical performance and energy-release efficiency of these propellants. This study developed a straightforward method using tannic acid (TA) and Fe3+ ions to create an interfacial layer on ammonium perchlorate (AP) particles (referred to as AP@TA-Fe) for achieving enhanced AP energy-release efficiency and mechanical properties of the propellant. AP@TA-Fe composites with different TA-Fe mass ratios (2, 4, and 6 wt%) were prepared, tested, and characterized. The experimental results demonstrated the interface-engineered AP@TA-Fe displayed enhanced hydrophobicity and rapid energy release, and these effects intensified with increasing interfacial layer thickness. The TA-Fe interfacial layer significantly enhanced the tensile strength and elongation of the propellant under various temperature conditions. As the thickness of the TA-Fe layer increased, the damage mechanism of the modified propellant shifted from the dewetting of the AP particles to the tearing of the adhesive matrix. Consequently, the AP@TA-Fe composites are expected to serve as superior substitutes for traditional AP in propellant applications. [ABSTRACT FROM AUTHOR]

Background and Objectives: Wood has some limitations in properties and applications due to its natural nature, which need to be modified. Wood modification is usually done with different aims and methods. One of the wood modification methods is thermal treatments in order to improvement of dimensional stability and biological resistance. But, it is surely affected on physical and mechanical properties of wood. Wood thermal modification in presence of oxygen causes the oxidation of its chemical structure which leads to detrimental effects on physical and mechanical properties. Therefore, elimination of oxygen in thermal modification can reduce its destructive effects. In current study, the effect of thermo-oil process on the function of white rot fungus has been investigated. Moreover, the effect of this process on engineering properties of birch and pine wood species was evaluated. Methodology: In this study, two wood species of birch (Betula sp.) and pine (Pinus sp.) wood were cut into the desired lumbers. Heat treatment of the prepared lumbers was carried out in a cylinder which is equipped with pressure and vacuum system. Also, industrial recycled oil was used for heat treatment of the lumbers. The temperature and time of treatment were selected as 195 °C and 5 hours, respectively. At the end of the process, the used oil was drained into the oil storage tank and the lumbers were removed from the cylinder after applying vacuum. In order to investigation of biological resistance as well as physical and mechanical properties (water absorption and swelling, density, mass loss, bending strength, compression strength parallel to the grain and impact strength) test specimens were prepared from the treated and control lumbers based on the standard. The SPSS software was used for statistical analysis. The results were statistically analyzed based on a One-Way ANOVA method. Results: Results revealed that thermo-oil treatment can reduce the functionality of white rot fungus and also its efficiency on physical and mechanical properties of both wood species. Moreover, the results showed that this process improved the physical properties and reduced the mechanical properties, except compression strength parallel to the grain. Conclusion: Thermo-oil treatment at high temperature causes structural changes of wood and affects its physical and mechanical properties. Also, the structural changes caused by heat treatment can be an effective and inhibiting factor to functionality of white rot fungus on physical and mechanical properties of wood. [ABSTRACT FROM AUTHOR]

Gerotors are a family of mechanical pumps used for cooling, lubrication and fuel transfer in aerospace, medicine, etc. Modern industry demands to shorten the development time of products. This means further integration between the different design stages. As in any hydraulic machinery, an important bottleneck in the design process is the simulation time to validate designs. This is due mainly to the fact that Computational Fluid Dynamics (CFD) remains the go-to tool to perform simulations of hydraulic phenomena. One way to reduce this bottleneck is to adopt approximate yet fast simulation routines to refine the design before entering a precise simulation stage. This manuscript presents an interactive design tool that estimates the efficiency response of gerotor pumps using fast simulation routines. The presented tool intends to shorten and accelerate the design cycles of Gerotor pumps by providing the engineer with an estimation of the effect of geometry changes in the pump's efficiencies in real time. The software tool integrates 2D and 3D design capabilities with real-time simulation response. The resulting efficiency estimations differ from the CFD models in maximum 8% in the case of volumetric efficiency. For mechanical efficiency the error ranges between around 20% and 45%, but the pump's internal forces is estimated within a 1% accuracy. Future work focuses on refining the accuracy of the efficiency estimations and further integration of the design tool with physical data. [ABSTRACT FROM AUTHOR]

The mechanical durability and efficiency of all‐inorganic flexible perovskite solar cells (f‐PSCs) still require enhancement for practical applications. In this study, a creative debridement strategy to improve the mechanical durability and photovoltaic performance of all‐inorganic f‐PSCs by pre‐bending the flexible perovskite film and then depositing the passivation agent 2‐mercaptopyridine is proposed. The pre‐bending process induced the generation of microcracks in the perovskite film surface, and 2‐mercaptopyridine can more effectively penetrate the interior of the film through the microcracks, thereby further passivating deep surface defects. These microcracks and defects can be perfectly repaired by 2‐mercaptopyridine. Bidentate coordination sites of S and N in 2‐mercaptopyridine show stronger binding energy with surface defects. The debridement strategy effectively enhanced the crystallization of the film surface and markedly inhibited crack propagation during the film's bending process. The optimized device achieves a champion power conversion efficiency (PCE) of 14.74%. The pre‐bent and passivated all‐inorganic f‐PSC shows 104% of its initial PCE after 15 000 bending cycles at a curvature radius of 3 mm. Remarkably, even after undergoing 70 000 bending cycles at a curvature radius of 5 mm, pre‐bent, and passivated f‐PSC can retain over 93% of its initial PCE, exhibiting excellent mechanical durability. [ABSTRACT FROM AUTHOR]

One of the main challenges in super high-density olive is maintaining hedgerow structure suitable for mechanical harvesting. Deficit irrigation strategies (DI) can contribute to this maintenance. In this study, three DI treatments at 50% of the Control (DI-1: budbreak to pre-bloom, DI-2: fruit set to pit hardening, and DI-3: pit hardening to harvest) were applied to 6-year-old Arbequina hedgerows in a semi-arid environment of Argentina over three consecutive seasons. The mean applied water reduction was 12% for DI-1 and 16% for DI-2 and DI-3, compared to Control (100% of ETc throughout the cycle). DI-3 achieved the narrowest hedgerows at harvest, where canopy height was responsive to irrigation and canopy width was affected by fruit load but not by the irrigation regime. DI-1 demonstrated similar fruit and oil yields to Control throughout the experiment, while DI-2 only had comparable yields to Control in Off-season. DI-3 had the lowest oil yields, averaging – 27% in Off and On-seasons. The fruit number was similar among treatments in all seasons, indicating that differences in final yield were related to fruit size and oil concentration. Further studies are needed to determine the optimal duration and intensity of the water deficit for DI-3. [ABSTRACT FROM AUTHOR]

This paper investigates the feasibility of the Biofuel and diesel used in a proportionate mixture as a Biodiesel as a replacement for Diesel fuel. Biodiesel has gained significant attention in the power world as an alternative to biodiesel blends prepared in this study is 50% Neem and 50% Pongamia pinnate. During the study, the blends used for testing were B5%, B10%, B15% and B20% with a varying load condition of 3kg to 20kg in a single-cylinder diesel engine at rpm of 1600 with a load of 19.01kg. A pyrolysis method is used for making Biodiesel. The viscosity values of the Biodiesel blend lie in the range of 3.89 to 8.756 Nm/s2 1. The performance of biodiesel has been analysed in terms of break power, indicated power, break and indicated thermal efficiency, mechanical efficiency, torque, specific fuel consumption, and volumetric efficiency. The parametric value of the all curve shows the increasing behaviour from lower to higher value. Volumetric efficiency shows only decreasing behaviour concerning load. The result shows the B5% blend is better in break power by 13.43% than a diesel at a load of 19.01kg. And specific fuel consumption. The torque generated is more efficient in B20% blends. Break thermal efficiency is proportional to the load of the engine. Indicated Thermal efficiency is much higher than diesel of B5% Biodiesel. The maintenance of a fuel pump is required regularly due to more viscosity problems. [ABSTRACT FROM AUTHOR]

This paper introduces a test system for microwave-assisted dual-mode mechanical cutting of hard rock under true triaxial compression. The test system was developed by Northeastern University, China, to simulate the cutting and breaking of hard rock by a tunnel boring machine (TBM). The test system is mainly composed of a dual-mode mechanical cutting subsystem, a true triaxial loading subsystem and a high-power microwave presplitting subsystem. The system performs dual-mode cutting under true triaxial stress, applies a single sensor to monitor the three-dimensional force of the cutter head, and integrates the reduction in the vibration and resistance to torsion during the cutting process. Mechanical cutting tests of basalt under different amounts of microwave irradiation and true triaxial stress conditions were conducted in Chifeng, Inner Mongolia, China. The results showed that microwave radiation presplitting effectively improved the efficiency of mechanical rock breaking. However, after 180 s of microwave irradiation, true triaxial high stress inhibited the mechanical breaking of basalt in terms of the overall excavation depth. During the tests, each system performed stably. The test results verified the reliability of the test system. Highlights: A true triaxial stress microwave-assisted mechanical dual-mode cutting test system is independently developed. The proposed system simulates rock breaking by a microwave-assisted roadheader under different ground stress conditions. The cutting test system innovates in three main facets: it carries out a dual-mode cutting test system in rock breaking; it realizes a unified monitoring output of a single sensor for the three-dimensional force; and it integrates the seismic resistance and torsion resistance to create a smooth system body. As the cutting test is conducted, the effective influence range of microwave radiation on rock is verified, and the degree of influence of true triaxial high stress on microwave-assisted mechanical cutting is revealed, providing guidance for deep microwave-assisted rock breaking of roadheaders. The necessity and feasibility of the system development is thus verified. [ABSTRACT FROM AUTHOR]

In automatic transmissions, hydraulic oil in the oil sump is strongly agitated by gears during operation; thus, the oil is mixed with great amounts of air. Air-mixed oil is sucked and discharged by a hydraulic pump to shift the gears. Although air bubbles mixed in the oil may affect the behavior of the rotors, driving torque, and discharge flow rate, they have hardly been measured. In this study, we measure them using a balanced vane pump and a gerotor pump used for automatic transmissions under varying air bubble contents and operating conditions. The experimental results revealed that the inclusion of air bubbles in the oil somewhat influenced the rotor behavior of both test pumps but it did not seem to increase the contact between the rotor and the surrounding stationary parts. Furthermore, as the bubble content increased, friction torque decreased to some degree, while discharge flow rate decreased to a great degree. This work proposed a new friction torque model, in which bubble content is included as a parameter, and the proposed model demonstrated relatively good agreement with the measured friction torque characteristics. The results also revealed that the rotor behavior and friction torque characteristic were mainly affected by bubble content and less so by bubble size. [ABSTRACT FROM AUTHOR]

Objective: This study investigated whether exposure to suboptimal gestational factors (SGFs) alters mechanical efficiency (ME) and substrate oxidation during rest and exercise in children as a mechanism contributing to obesity. Methods: Data from the Quebec Adiposity and Lifestyle Investigation in Youth cohort were used. Children aged 8 to 10 years performed an incremental maximal cycling test with indirect calorimetry. Their ME was measured during submaximal and maximal effort. The substrate oxidation during rest and submaximal effort was also computed. ME and substrate oxidation results between children exposed to each SGF during pregnancy (gestational diabetes mellitus: n = 68; hypertensive disorders: n = 49; maternal smoking: n = 77) and nonexposed children (n = 370) were compared. Results: No difference was observed for ME during submaximal (F[3,540] = 0.46, p = 0.713) and maximal effort (F[3,545] = 0.86, p = 0.463) between exposed and nonexposed children. The percentage contributions of lipids and carbohydrates did not differ during rest (F[3,545] =1.68, p = 0.169) or submaximal exercise (F[3,544] = 0.31, p = 0.534) between exposed and nonexposed children. Conclusions: Children exposed to investigated SGFs display a similar physiological response regarding ME and substrate oxidation during rest and exercise compared to nonexposed children. Future studies should confirm these novel results and continue investigating other research avenues to explain the higher risk of obesity in this population. [ABSTRACT FROM AUTHOR]

A high voltage circuit breaker (HVCB) plays a crucial role in current smart power system. However, the current research on HVCB mainly focuses on the convenience and efficiency of mechanical structures, ignoring the aspect of their fault diagnosis. It is very important to ensure the circuit breaker conducts in a normal state. According to real statistics when HVCB works, most defects and faults in high voltage circuit breakers is caused by mechanical faults such as contact fault, mechanism seizure, bolt loosening, spring fatigue and so on. In this study, vibration sensors were placed at four different locations in the HVCB system to detect four common mechanical faults using vibration signal. In our approach, a convolutional attention network (CANet) was introduced to extract features and determine which mechanical faults occur within a fixed period of time. The results indicate that the mechanical fault diagnosis accuracy rate is up to 94.2%, surpassing traditional methods that rely solely on vibration signals from a single location. [ABSTRACT FROM AUTHOR]

Introduction: Domestic production of pepper (Capsicum spp.) is shrinking while demand within the US is growing. Lack of availability and cost of labor often present an obstacle for domestic producers both practically and economically. As a result, switching to harvesting peppers mechanically is anticipated as a key strategy to help domestic producers compete in the international market. Mechanical harvest efficiency can be improved through breeding. One important trait that mechanical harvest compatible material should have is an easy destemming trait: low force separation of the pedicel and calyx fromthe fruit. Methods: To detect the genetic sources underlying a novel easy destemming trait for the purpose of future breeding efforts in New Mexico pod-type green chile, we performed QTL analysis on three F2:F3 populations, coming from three New Mexico pod-type varieties: 'NuMex Odyssey,' 'NuMex Iliad,' and 'NuMex Joe E. Parker,' each crossed with a parent with an easy destemming trait: MUC14. Genotyping was done through genotyping by sequencing (GBS) and phenotyping was done for destemming and fruit trait measurements. Correlations between measurements were found through the R package hmisc and QTL analysis was done through R/qtl. Results: A strong relationship was seen between destemming and aspects of fruit morphology, particularly, destemming force and fruit width (Pearson's correlation coefficient r=0.75). Major QTLs for destemming and fruit size were discovered. Of these, the largest destemming force QTLs for all populations (PVE=34.5-69.9%) were on chromosome 10, and in two populations QTLs for destemming force were found on chromosome 3 (Percent Variance Explained (PVE)=10.7-18.8%). Fruit size-related QTLs in all populations colocalized in these same areas on chromosomes 3 and 10. Discussion: This suggests that fruit shape may be genetically linked to destemming, and breeders interested in selecting for easy destemming pepper will also have to pay attention to fruit size and shape. [ABSTRACT FROM AUTHOR]

AbstractBackgroundAimMaterials and MethodsResultsConclusion\nIMPLICATIONS FOR REHABILITATIONWhen selecting a manual wheelchair frame, the choice between rigid and folding frames carries significant implications. Traditional folding frames are expected to have more rolling resistance and power dissipation caused by frame deformation, while they are more convenient for transportation, such as in a car. A new hybrid frame, designed to be more rigid, aims to minimize power dissipation while still retaining foldability.This study aimed to assess rolling resistance, power output, propulsion technique and physiological demands of handrim wheelchair propulsion across three different frames: a rigid frame, a hybrid frame and a conventional folding frame.Forty-eight able-bodied participants performed coast-down tests using inertial measurement units to determine rolling resistance. Subsequently, four-minute submaximal exercise block under steady-state conditions at 1.11 m/s were performed on a wheelchair ergometer (n = 24) or treadmill (n = 24) to determine power output, propulsion technique and physiological demands.Repeated measures ANOVA revealed that the hybrid frame exhibited the lowest rolling resistance (7.0 ± 1.5N, p ≤ 0.001) and required less power output (8.3 ± 1.0W, p ≤ 0.001) at a given speed, compared to both the folding (9.3 ± 2.2N, 10.8 ± 1.4W) and rigid frame (8.0 ± 1.9N, 9.4 ± 1.6W). Subsequently, this resulted in significantly lower applied forces and push frequency for the hybrid frame. The folding frame had the highest energy expenditure (hybrid: 223 ± 44 W, rigid: 234 ± 51 W, folding: 240 ± 46 W, p ≤ 0.001).The hybrid frame demonstrated to be a biomechanically and physiologically beneficial solution compared to the folding frame, exhibiting lower rolling resistance, reduced power output, and consequently minimizing force application and push frequency, all while retaining its folding mechanism.A hybrid frame, developed as an intermediary solution between a folding and rigid frame, presents reduced biomechanical and physiological demands compared to a folding frame. This is attributed to its decreased need for propulsive forces and energy expenditure, resulting from lower rolling resistanceDespite the hybrid frame offering lower rolling resistance and thus requiring less propulsive force as the rigid frame, it experiences internal power losses due to movement between its interconnected pieces. Consequently, the net mechanical efficiency of the hybrid frame is inferior to that of the rigid frame, resulting in a similar energy expenditure between the hybrid and rigid frames.The hybrid frame emerges as a potentially more advantageous option than a conventional folding frame, as it diminishes biomechanical and physiological strain while retaining a folding mechanism, to ensure easy transportation.A hybrid frame, developed as an intermediary solution between a folding and rigid frame, presents reduced biomechanical and physiological demands compared to a folding frame. This is attributed to its decreased need for propulsive forces and energy expenditure, resulting from lower rolling resistanceDespite the hybrid frame offering lower rolling resistance and thus requiring less propulsive force as the rigid frame, it experiences internal power losses due to movement between its interconnected pieces. Consequently, the net mechanical efficiency of the hybrid frame is inferior to that of the rigid frame, resulting in a similar energy expenditure between the hybrid and rigid frames.The hybrid frame emerges as a potentially more advantageous option than a conventional folding frame, as it diminishes biomechanical and physiological strain while retaining a folding mechanism, to ensure easy transportation. [ABSTRACT FROM AUTHOR]

Microwave treatment has become a promising method to improve the efficiency of mechanical excavators in hard rocks. This paper conducted microwave irradiation tests on three water-bearing sandstones and analyzed the heating and water-escaping process by real-time temperature and mass measurement. Meanwhile, nuclear magnetic resonance tests were performed to investigate the water transport behavior inside the samples under microwave irradiation. The results show that the thermal behaviors are jointly governed by the water content, permeability and microwave power used. As the sample temperature increase, the contained water would firstly transport from the drying front to the surface driven by the temperature gradient. Subsequently, water began to escape from the sample with a rate determined by the permeability of the sandstone. At this stage, energy dissipation brought by water escaping would slow down the initial heating rate. Hence, the thermal cracking of the sandstones under microwave irradiation can hardly be enhanced by the existence of pore water in spite of its superior dielectric properties. Nevertheless, the vapor pressure could be large enough to burst the sample when water was heated to a high temperature. Highlights: Obtained the real-time temperature and mass change under microwave irradiation Investigated the water transport behavior in sandstones using nuclear magnetic resonance techniques Discussed the role water plays in microwave heating, fracturing and bursting of sandstones [ABSTRACT FROM AUTHOR]

This article explores the intersubjective relationships between clients and workers on two digital domestic work platforms in Bogotá, Colombia. Drawing on feminist social studies of science and technology, it investigates the control, auditing, and subordination mechanisms affecting workers, with clients playing a key role in setting performance conditions. While much of the literature on digital labor focuses on technological intermediation and algorithmic management--used to track, monitor, and rate domestic workers--this article looks at the relationships with clients and how these shape the work process and technologies involved. Based on over thirty in-depth interviews with workers and clients, the study examines three areas: (i) clients' expectations of mechanical efficiency; (ii) the use of rating systems; and (iii) domestic work as emotional labor. The article concludes by reflecting on the dual subordination experienced by workers due to digital service intermediaries and emphasizes the need for fair technologies that consider workers' experiences and perspectives. [ABSTRACT FROM AUTHOR]

The efficiency of mechanical crushing is a key metric for evaluating machinery performance. However, traditional contact-based methods for measuring this efficiency are unable to provide real-time data monitoring and can potentially disrupt the production process. In this paper, we introduce a non-contact measurement technique for mechanical crushing efficiency based on deep learning algorithms. This technique utilizes close-range imaging equipment to capture images of crushed particles and employs deeply trained algorithmic programs rooted in symmetrical logical structures to extract statistical data on particle size. Additionally, we establish a relationship between particle size and crushing energy through experimental analysis, enabling the calculation of crushing efficiency data. Taking cement crushing equipment as an example, we apply this non-contact measurement technique to inspect cement particles of different sizes. Using deep learning algorithms, we automatically categorize and summarize the particle size ranges of cement particles. The results demonstrate that the crushing efficiencies of ore crushing particles, raw material crushing particles, and cement crushing particles can respectively reach 80.7%, 70.15%, and 80.27%, which exhibit a high degree of consistency with the rated value of the samples. The method proposed in this paper holds significant importance for energy efficiency monitoring in industries that require mechanical crushing. [ABSTRACT FROM AUTHOR]

This study investigated the effects of biodiesel-pentanol blends on the mechanical performance of a diesel engine operated at varied compression ratios. Biodiesel was produced through transesterification of corn oil with methanol using a potassium hydroxide catalyst. Six fuel blends were tested consisting of 100% diesel, 80% diesel + 20% biodiesel, 80% diesel + 20% pentanol, and blends containing 10%, 15%, and 20% proportions of biodiesel and pentanol. The engine was tested on an eddy current dynamometer over a range of loads while measuring performance parameters such as brake torque, power, brake thermal efficiency, and brake specific fuel consumption. The results showed that adding pentanol to the biodiesel blends enhanced the engine's mechanical efficiency and torque output compared to the 20% biodiesel blended with diesel. Specifically, a blend containing 20% biodiesel and 20% pentanol improved torque by 16.7% relative to the 20% biodiesel blend. Overall, pentanol-biodiesel blends show potential as viable alternative fuels for diesel engines. [ABSTRACT FROM AUTHOR]

Radial piston motors are executive components in hydraulic systems, tasked with providing appropriate torque and speed according to load requirements in practical applications. The purpose of this study is to predict the output torque of radial piston hydraulic motors and confirm their suitable operating conditions. Efficiency determination experiments were conducted on physical models, yielding thirty sets of performance data. Torque (output torque) and mechanical efficiency from the experimental data were selected as prediction targets and fitted using two methods: multiple linear regression and neural networks. A dynamic simulation model was built using Adams2020 software to obtain theoretical torque values, enabling the verification of the alignment between the predicted values and simulation results. The results indicate that the error between the theoretical torque of the dynamic model and the physical experiments is 1.9%, with the error of the neural network predictions being within 2%. The dynamic simulation model can yield highly accurate theoretical torque values, providing a reference for the external load of hydraulic motors; additionally, neural networks offer accurate predictions of output torque, thus reducing experimental testing costs. [ABSTRACT FROM AUTHOR]

Drilling is a complex destructive action that induces vibrations due to the rock-bit interaction, which affects the overall drilling efficiency and wellbore quality. This study aims to enhance drilling efficiency by deploying artificial neural networks (ANNs) to integrate in-cutter force sensing and vibration data. Data is collected from experiments conducted with sharp cutters on rock samples of varying mechanical properties, measuring variables such as weight on bit, torque, rotational speed, in-cutter force, and vibration measurements. A scoring system is used to evaluate the drilling efficiency by coupling the mechanical specific energy and vibration modes. An ANN is trained with these variables to predict the rate of penetration and rock strength, which are also measured in the experiments to be used as ground truth. The reliability of the framework is demonstrated by testing the validity of the ANN model on samples with various mechanical properties. It introduces a reliable and swift method for determining optimal drilling parameters, supported by a sensitivity analysis to fine-tune the ANN and assess the influence of each parameter on performance. This study demonstrates that ANN could be successfully implemented to predict the rate of penetration and rock strength on a laboratory-scaled drilling rig. The results show that the ANN model accurately predicts training and testing datasets for scoring while drilling multiple layers with a correlation coefficient of 0.966. Integration of in-cutter sensing technology, vibration data, and ANN can be of significant interest and be used on field applications to provide a reliable and rapid decision about drilling efficiency. [ABSTRACT FROM AUTHOR]

One-dimensional structured fillers play a crucial role in promoting the rapid and spontaneous healing of defects induced by damage in self-healing coatings. This innovative type of self-healing coating prevents the substrate material from corroding, thereby significantly extending its service life. The modification of self-healing coatings with one-dimensional structured fillers relies on functional additives to efficiently heal coating damage, distinguishing it from traditional approaches involving microcapsules and nanoencapsulated particles. The incorporation of advanced fillers not only enhances the local reconstruction efficiency and mechanical properties of the coating but also enables the coating to heal the damage repeatedly. In this paper, the latest research progress on one-dimensional structured fillers for self-healing coatings is reviewed from three aspects: types of functional fillers with one-dimensional structures, packaging processes for repairing agents in fillers, and self-healing mechanisms of the composite coating. Furthermore, future work has been proposed to address present problems in the research of one-dimensional structured filler-modified self-healing coatings. One-dimensional structured fillers and their applications in self-healing composite coatings. [ABSTRACT FROM AUTHOR]

CF‐PDA‐M hybrid fillers are prepared by three metal cations (M) assisting polydopamine (PDA) through Fe3+, Ni2+, and Al3+. The metal cations promote the polymerization of PDA on the fiber surface, shorten the modification time of the fibers, and ensure that the short‐cut carbon fibers (CF) do not agglomerate during water bath stirring while keeping the structure of the CF undamaged, which is a green and efficient method. After PDA modification, the roughness and surface activity of the fiber surface increase. Finally, CF‐PDA‐M is used as a filler and added to neoprene latex and natural latex, which are prepared into composites by wet blending, and the CF are characterized by different techniques. The results show that the hydroxyl and amino groups on the surface of CF‐PDA‐M increase the cross‐linking density of the composites, establish a good stress cross‐linking network, shorten the vulcanization time, effectively prevent the agglomeration phenomenon of the CF in the rubber, and improve the dispersion of the CF in the composite. After modification, the tensile strength and 300% constant tensile strength of CF‐PDA‐M increase by more than 10% and 30%, respectively, over CF composites, and the rolling resistance is reduced. This study provides a new and effective strategy for CF surface functionalization, which improves the processing efficiency and mechanical properties of rubber products and has a broad application prospect in the rubber industry. [ABSTRACT FROM AUTHOR]

This study investigates the performance dynamics of a six-cylinder, inline compression ignition engine, focusing on its response to varying turbocharger compressor pressure ratios (TCPRs). At a constant speed of 1500 RPM, the engine's power output, braking mean effective pressure, and brake torque increase significantly, ranging from 280 kW, 11.7 bar, and 1779.7 N m at a TCPR of 2–1042.6 kW, 43.7 bar, and 6637.8 N m at a TCPR of 10. This demonstrates a direct relationship between TCPR and engine performance metrics. Additionally, mechanical efficiency improves with increasing TCPR, indicating enhanced adaptability and efficiency of the engine. The study analyzes the effects of turbochargers, exhaust and intake characteristics, NOx emissions, combustion dynamics, and compressor settings, providing a comprehensive understanding of the relationship between turbocharging and compression ignition engines. These insights can support future research aimed at optimizing engine performance across various TCPR settings.