Balance Strength Research Articles

Bimetallic Phthalocyanine Monolayers as Promising Materials for Toxic H2S, SO2, and SOF2 Gas Detection: Insights from DFT Calculations.

The development of a high-performance gas sensor for the rapid and efficient detection of harmful SF6 decomposition gases (H2S, SO2, and SOF2) is crucial for equipment environmental monitoring and safeguarding human health. In this work, first-principles calculations were conducted to assess the adsorption performance and sensing characteristics of these decomposition gases on two-dimensional metal-dimer-modified phthalocyanine (Mn2Pc, Tc2Pc, and MnTcPc) surfaces. The results demonstrate that the Mn2Pc, Tc2Pc, and MnTcPc monolayers possess enhanced structural stability. The Mn2Pc, Tc2Pc, and MnTcPc monolayer materials show strong adsorption capabilities (|Eads| > 0.90 eV) and significant electron transfer (|Qt| > 0.017 e) and interact favorably with the aforementioned toxic gases, indicating their superior adsorption capacities for SOF2, SO2, and H2S. The microscopic interaction mechanisms between SF6-decomposed gas molecules and the Mn2Pc, Tc2Pc, and MnTcPc nanosheets are elucidated through analyses of electron density distribution, differential charge distribution, and density of states. Furthermore, upon absorption of H2S, SO2, and SOF2, the work function and band gap energy of the Mn2Pc, Tc2Pc, and MnTcPc monolayers undergo significant changes, and the magnetic moments of the Mn2Pc, Tc2Pc, and MnTcPc monolayers also exhibit substantial alterations, suggesting high sensitivity to H2S, SO2, and SOF2. Considering the balance of adsorption strength, sensitivity, and recovery time, the single-layer films of Mn2Pc, Tc2Pc, and MnTcPc are deemed to be gas-sensing materials with significant potential, suitable for the development of sustainable gas sensors targeting H2S, SO2, and SOF2 with effective recovery capabilities.

Strategic enhancement of joint strength in dissimilar Al/Mg alloys: a workable approach for aerospace application

The increasing importance of dissimilar lightweight metal joints is crucial for advancing aerospace and automotive technologies, where aluminum (Al) and magnesium (Mg) alloys offer an ideal balance of strength and weight. However, the challenges associated with joining these dissimilar metals necessitate innovative solutions. This study explores the role of silicon carbide (SiC) nanoparticles in enhancing the friction stir spot welding (FSSW) of dissimilar alloys AA6061 and AZ31B. The methodology involved varying the rotational speed of the welding tool (1000, 1200, 1400, and 1600 rpm) while keeping other parameters such as plunge depth, plunge rate, and dwell time constant. SiC nanoparticles were introduced through a pre-drilled 2 mm hole at the tool’s plunging point to refine the microstructure and mitigate the formation of brittle Al–Mg intermetallic compounds (IMCs). The addition of SiC nanoparticles modifies the weld microstructure, reducing the formation of brittle Al–Mg IMCs and promoting the development of finer, well-distributed Mg–SiC IMCs, resulting in a more favorable and homogeneous multilayered structure. The incorporation of SiC significantly enhances the strength of the joints, achieving a maximum of 5.68 kN, 22.7% increase compared to SiC-free Al/Mg joints. This improvement underscores potentiality of SiC as a reinforcing element in strengthening dissimilar metal joints and demonstrates the effectiveness of it in dissimilar Al/Mg joints, making them suitable for aerospace and automotive applications.

Adjustmentalisation - digitalisation as transformation process and the interplay between a digital logic and diverse primary care logics in Sweden.

This study aims to contribute with knowledge on the characteristics of the process of co-existence of value conflicts between managers, markets/businesses, patients, professionals and digital technology in primary care practices, to be able to nuance the array of descriptions of the consequences of introducing a digitalised care practice, such as telemedicine, into an already existing primary care organisation. Due to its organisational structure and dynamic environment with a multitude of professions and patients as well as influenced by managerial and market drivers, the primary care setting provides fertile ground for studying value conflicts from an institutional logic perspective. This multi-source study utilises qualitative thematic content analysis on empirical data collected through interviews, a survey and documents, followed by an iterative analysis in regard to institutional logics based on the themes developed from empirical data. Coexistence and Adaptation: Different logics coexist and transform through adjustmentalisation rather than competing or dominating each other. Digital Technology's Influence: Digital technology influences and interacts with all established logics, potentially acting as a separate, evolving logic. Changing Healthcare Conditions: New conditions and digital solutions in healthcare may shift the balance of logics, potentially normalising managerial and market logics. Patient Empowerment and Data Ownership: Increasing emphasis on patient empowerment and transparent data processing under regulations like General Data Protection Regulation (GDPR) and Medical Devices Regulation (MDR). With its qualitative design there is not an emphasis on generalisability. The study is performed in a Swedish primary care setting. Regarding its practical implications, this study examines digitalisation and the introduction of eHealth solutions in primary care in Sweden. The adjustmentalisation of diverse institutional logics described in this study was used to try to facilitate the implementation of eHealth and telemedicine in primary care. This practical contribution could be used in other primary care organisation that plans to introduce eHealth solutions as part of their practices. This study may also have practical implications for other healthcare organisations since the presence of diverse institutional logics is not unique to primary care. Firstly, this study confirms earlier studies that argue that co-existence of diverse logics is possible in everyday practice. However, we show that adjustmentalisation of the diverse logics rather than the balance of strengths between them, facilitates the transformation, regulation and coordination of the new eHealth practice in relation to established practices. Secondly, this study shows that the adjustmentalisation derives from societal challenges such as an ageing population, accessibility problems and the COVID pandemic that are used to legitimise the adjustmentalisation of diverse logics. Digital technology influences and interacts with all established logics, potentially acting as a separate, evolving logic. Coexistence and adaptation: Different logics coexist and transform through adjustmentalisation rather than competing or dominating each other.Digital technology's influence: Digital technology influences and interacts with all established logics, potentially acting as a separate, evolving logic.Changing healthcare conditions: New conditions and digital solutions in healthcare may shift the balance of logics, potentially normalising managerial and market logics.Patient empowerment and data ownership: Increasing emphasis on patient empowerment and transparent data processing under regulations like GDPR and MDR.Future research directions: Need for further research on digital technology's impact on shift and balance between logics, business development, patient participation and its potential to become a dominant logic.

Electrospun scaffold with bioactive polyurethane shell infused with propolis and starch-hyaluronic acid core: An advanced therapeutic platform for skin tissue engineering.

Biological macromolecules such as polysaccharides and proteins, due to their excellent biocompatibility and biodegradability, are ideal for promoting Skin Tissue Engineering (STE) both in vitro and in vivo. In this study, a core-shell electrospun scaffold was fabricated using the coaxial electrospinning method, with Polyurethane (PU) forming the shell and a mixture of Starch (ST), Propolis Extract (PE), and Hyaluronic Acid (HA) forming the core. The scaffold's morphology was characterized by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), confirming the successful formation of a well-defined core-shell structure. The scaffold exhibited a contact angle of 56.7°, reflecting its favorable hydrophilic properties for cellular attachment. Mechanical testing revealed Young's modulus of 8.12MPa and a strain at break of 46%, indicating an optimal balance of mechanical strength and elasticity for STE. Antibacterial tests demonstrated that the core-shell structure exhibited strong antimicrobial activity against Staphylococcus aureus and Escherichia coli, making them a potential candidate. Cytotoxicity assessments showed no toxicity, with L929 fibroblast cells demonstrating enhanced adhesion and proliferation on the core-shell structure compared to control samples. These findings suggest that the PU-shell and ST/PE/HA-core electrospun scaffold represents a promising multifunctional platform for advanced STE and regenerative medicine applications.

Comparative study on psychological characteristics and biomechanical indicators of rock climbers at different levels: An analysis based on self-efficacy, sport motivation, and muscle function performance

Background: Rock climbing is a comprehensive sport that integrates physical strength, coordination, and psychological resilience. Significant differences may exist in the psychological states and biomechanical performance of athletes at different levels. However, systematic studies on the psychological characteristics and biomechanical indicators of rock climbers at different levels remain limited. Objective: This study aimed to compare the psychological indicators (e.g., self-efficacy and sport motivation) and biomechanical characteristics (e.g., muscle activation levels, relative peak torque, and flexor-extensor peak torque ratios) of rock climbers to explore the differences and intrinsic relationships between athletes of different skill levels. The findings aimed to provide a theoretical basis for optimizing performance and designing training strategies. Methods: Twenty-two rock climbers participated in the study, including 11 elite athletes and 11 novice athletes. Psychological indicators were assessed using standardized questionnaires, including self-efficacy and five dimensions of sport motivation: Fun motivation, ability motivation, appearance motivation, health motivation, and social motivation. Biomechanical data were collected using the Noraxon DTS surface electromyography (sEMG) system and the Biodex System 4 isokinetic dynamometer, which measured muscle activation levels and the relative peak torque and flexor-extensor peak torque ratios of the shoulder, elbow, hip, knee, and ankle joints at speeds of 60°/s, 120°/s, and 180°/s. Muscle activation signals were normalized as %MVC, and peak torque values were extracted for analysis. The data were grouped by athlete level, and independent sample t-tests were conducted to compare group differences, with significance set at p < 0.05. Results: Elite athletes demonstrated significantly higher psychological indicators than novice athletes, particularly in self-efficacy (3.19 ± 0.671 vs. 2.77 ± 0.341) and fun motivation (3.28 ± 1.049 vs. 2.78 ± 0.47). Additionally, elite athletes exhibited higher muscle activation levels and relative peak torque in upper limb and core muscle groups compared to novice athletes (p < 0.05), indicating superior strength control and coordination. Conversely, novice athletes had relatively higher peak torque in lower limb muscle groups but showed deficiencies in strength balance and coordination. Conclusion: Significant differences were found in the psychological states and biomechanical characteristics of rock climbers at different levels. These differences likely contribute to variations in athletic performance. Elite athletes displayed stronger psychological advantages and superior strength in upper limb and core muscle groups. In contrast, novice athletes needed to enhance sport motivation and improve upper limb and core strength to develop comprehensive athletic abilities. This study provides a scientific basis for optimizing training strategies for rock climbers at different levels and lays a foundation for future research on the mechanisms underlying climbing performance.

Optimization of Deposition Temperature and Gyroid Infill to Improve Flexural Performance of PLA and PLA–Flax Fiber Composite Sandwich Structures

This research investigates the optimization of 3D-printed sandwich structures fabricated using fused filament fabrication (FFF) with polylactic acid (PLA) and PLA reinforced with flax fibers. The core of the sandwich structure features a gyroid infill pattern, which is known for its mechanical efficiency. The study delves into the effects of deposition temperature on the adhesion between the core and skin layers, as well as the impact of infill density on the overall mechanical properties. Three-point bending tests are conducted to assess the flexural performance of the structures. The objective is to identify the optimal processing parameters to enhance the performance of PLA-based composite sandwich structures. Potential applications for these structures include lightweight components for automotive interiors, sustainable packaging solutions, and architectural elements requiring a balance of strength and environmental sustainability.

Strength and dynamic balance performance in soccer players in the United States: age, sex, and bilateral differences.

Quantification of asymmetries between the two limbs is informative in assessing the risk of injury and performance deficits, but there is a paucity of studies investigating the effects of age and sex on bilateral asymmetry in young soccer players. This cross-sectional study aimed to investigate the effects of age and sex on strength and dynamic balance in 7- to 24-year-old soccer players in the United States. A total of 174 young soccer players participated in the study (Age 7-9 years: 26 females and 16 males; Age 10-12 years: 32 females and 31 males; Age 13-17 years: 17 females and 25 males; Age >18 years: 13 females and 14 males). Jump displacement, peak force, and asymmetry during countermovement jump with arm swing and landing, peak force and asymmetry during push-up, and normalized reaching distances for upper and lower extremity reaching tests were quantified. Preferred legs and arms were defined as the preferred kicking leg or throwing arm. As age increased, both preferred and non-preferred sides demonstrated decreased landing forces, increased jump displacement, and increased normalized peak forces during push-ups in both males and females (p < 0.05). Males showed greater jump displacement, normalized landing forces, and normalized peak forces in push-ups compared to females in several age groups (p < 0.05). No significant differences were observed for asymmetry variables between ages or sexes, and on average, most bilateral asymmetry variables were less than 5%. Age was associated with strength but not dynamic balance performance in healthy soccer players in the United States. Male and female players demonstrated similar changes, and bilateral asymmetries were on average small. Soccer players may need more dynamic balance training over time as they progress to higher levels of competition. Landing technique training may be implemented for young soccer players to decrease the high impact landing forces and landing related injury risk. Asymmetries and their relationships with injury risk should be evaluated on an individual basis, as their relationships with age and sex were weak. Future longitudinal and cohort studies are warranted to further elucidate the relationship among strength, dynamic balance, and injury risk in soccer players.

Ankle instability and physiotherapy: Exploring novel rehabilitation approaches

AbstractA common ailment that affects many people, especially athletes, ankle instability is frequently brought on by acute injuries that result in long-term pain and functional restrictions. This article examines both cutting-edge techniques like neuromuscular training, sport-specific drills, and technology-enhanced rehabilitation as well as more conventional approaches like strength training and balance exercises. Physiotherapists can develop customised regimens that enhance recovery results and lower the chance of re-injury by combining these tactics. Validating these novel approaches and improving rehabilitation procedures require ongoing research.

Microstructural Influences on High Cycle Fatigue Crack Initiation Mechanism in Ti-Al-Mo-Cr-V-Nb-Zr-Sn Metastable β Titanium Alloy.

In this work, the high cycle fatigue behavior and tensile properties of Ti-Al-Mo-Cr-V-Nb-Zr-Sn titanium alloy at room temperature with a basketweave structure and bimodal structure were studied. The results show that the fatigue strength of the basketweave structure is higher, while the balance of strength and plasticity of the bimodal microstructure is better. However, the fatigue performance of the bimodal microstructure is unstable due to the bilinear phenomenon of the S-N curve. By fractographic analysis and the study of the crystal orientation, as well as the slip traces of the primary α grains and β matrix at the facets, it was found that the facets are formed on the {101¯1}<112¯0> slip system with the highest Schmid factor, and the microcracks grow along the {110}<111> slip system in the β grain, but the driving force of microcrack propagation may exceed the restriction of crystallographic orientation. Based on the conclusions above, the phenomenological models of the fatigue crack initiation mechanism of Ti-Al-Mo-Cr-V-Nb-Zr-Sn titanium alloy are established.

Influence of cervical muscle strength and pain severity on functional balance and limits of stability in elderly individuals with chronic nonspecific neck pain: a cross-sectional study

BackgroundChronic nonspecific neck pain (CNSNP) is a common musculoskeletal disorder, particularly in the elderly, leading to reduced cervical muscle strength, impaired functional balance, and decreased postural stability. This study investigated the correlation between cervical muscle strength, functional balance, and limits of stability (LOS) in elderly individuals with CNSNP. Additionally, it assessed the moderating effect of pain severity on the relationship between cervical muscle strength and these balance outcomes.MethodsA prospective study included a total of 186 participants, including 93 with CNSNP and 93 asymptomatic individuals, were recruited. Cervical flexor and extensor muscle strength were assessed using an ergoFET hand-held dynamometer. Functional balance was measured using the Berg Balance Scale (BBS) and Timed Up and Go (TUG) test, while LOS were evaluated using the Iso-Free machine.ResultsIndividuals with CNSNP exhibited significantly lower cervical flexor strength (32.45 ± 5.67 N vs. 40.75 ± 5.20 N, p < 0.001) and extensor strength (28.30 ± 6.05 N vs. 36.90 ± 5.90 N, p < 0.001) compared to asymptomatic individuals. Functional balance was also poorer in the CNSNP group, with lower BBS scores (47.85 ± 4.20 vs. 53.65 ± 3.85, p < 0.001) and slower TUG times (11.30 ± 2.05 s vs. 8.45 ± 1.80 s, p < 0.001). Cervical muscle strength showed moderate to strong positive correlations with LOS (r = 0.56 to 0.62, p < 0.001) and BBS (r = 0.48 to 0.53, p < 0.001). Pain severity significantly moderated the relationship between cervical muscle strength and functional balance (β = 0.20, p = 0.045) as well as LOS (β = 0.22, p = 0.038), suggesting that higher pain levels diminish the positive effects of muscle strength on balance.ConclusionCervical muscle strength plays a crucial role in maintaining functional balance and postural stability in elderly individuals with CNSNP. Pain severity moderates the relationship between cervical muscle strength and balance outcomes, emphasizing the importance of integrating muscle strengthening and pain management in rehabilitation programs for elderly individuals with CNSNP to optimize postural control and minimize fall risk.

Effect of Stress Aging on Strength, Toughness and Corrosion Resistance of Al-10Zn-3Mg-3Cu Alloy.

The 7000 series aluminum alloy represented by Al-Zn-Mg-Cu has good strength and toughness and is widely used in the aerospace field. However, its high Zn content results in poor corrosion resistance, limiting its application in other fields. In order to achieve the synergistic improvement of both strength and corrosion resistance, this study examines the response of strength, toughness and corrosion resistance of a high-strength aluminum alloy tail frame under aging conditions with external stresses of 135 MPa, 270 MPa and 450 MPa. The results show that with the increase in the external stress level, the strength of the alloy improves, while its corrosion resistance decreases. An optimal balance of strength, toughness and corrosion resistance is achieved at the conditions of 270 MPa-120-24 h. This phenomenon can be attributed to two main factors: first, lattice defects such as vacancy and dislocation are introduced into the stress aging process. The introduction of a vacancy makes it easier for neighboring solute atoms to migrate there. This makes the crystal precipitates more dispersed. Also, the number of precipitates in the matrix increases from 2650 to 3117, and the size is refined from 2.96 nm to 2.64 nm. At the same time, the dislocation entanglement within the crystal structure promotes the dislocation strengthening mechanism and promotes the solute atoms to have enough channels for migration. Since too many dislocations can cause the crystal to become brittle and thus reduce its strength, entangled dislocations hinder the movement of the dislocations, thereby increasing the strength of the alloy. Secondly, under the action of external force, the precipitated phase is discontinuous, which hinders the corrosion expansion at the grain boundary, thus improving the corrosion resistance of the alloy. At low-stress states, the binding force of vacancy is stronger, the precipitation free zone (PFZ) is significantly inhibited, and the intermittent distribution effect of intergranular precipitates is the most obvious. As a result, the self-corrosion current decreases from 1.508 × 10-4 A∙cm-2 in the non-stress state to 1.999 × 10-5 A∙cm-2, representing an order of magnitude improvement. Additionally, the maximum depth of intergranular corrosion is reduced from 274.9 μm in the non-stress state to 237.7 μm.

Multi-scale finite element analysis of the strengthening and damage behavior of carbides with different characteristics in nickel-based superalloys

This study proposes a novel multi-scale numerical approach to explore the mechanical behavior and damage evolution in nickel (Ni)-based superalloys containing various carbide particles. At the nanoscale, the elastic properties of two distinct carbides are determined using first-principles calculations. At the microscale, finite element simulations (FEM) in ABAQUS are used to analyze the stress–strain relationship and local stress distribution within a three-dimensional representative volume element, as well as damage and fracture behavior. The model integrates the elastic–plastic response of the Ni matrix, the elastic-brittle fracture of micro-scale carbides, and the interface behavior between carbide and matrix. FEM findings are consistent with tensile test data, indicating that skeletal carbide promotes plasticity while blocky carbide elevates strength. The interface between blocky carbide and matrix is susceptible to cracking. When the carbide is oriented at 45° to the load direction, offering a balance of strength and plasticity. Stress concentration is reduced when carbides are uniformly distributed and present in high-volume fractions. The numerical method is well-suited for a thorough analysis of the comprehensive behavior of reinforced phase/metal-matrix composites.

Effects of Melatonin Supplementation on Muscle Strength, Manual Dexterity, and Postural Balance in Patients Living with Multiple sclerosis - A Randomized Controlled Trial

Our previous study revealed the benefits of chronic melatonin intake on dynamic postural imbalance and poor walking capacity induced by multiple sclerosis but its impact on muscle weakness and poor manual dexterity related to this disease has not yet been explored. The objective of the current study was to investigate the effectiveness of 12-week melatonin supplementation on motor skills (i.e., muscle strength, manual dexterity, and static postural balance) and psycho-cognitive status among multiple sclerosis patients. For that, twenty-seven patients were divided into melatonin group (MG, n = 15) and placebo group (PG, n = 12). Melatonin and placebo were each taken at a dose of 3 mg per night, 30 min before bedtime, for 12 weeks. Before and after the intervention, we assessed isokinetic knee muscle strength (dynamometer), manual dexterity (Nine-Hole Peg Test (NHPT)), static postural balance (force platform), mood (Hospital Anxiety and Depression Scale (HADS)), and cognition (Montreal Cognitive Assessment (MoCA), Symbol Digit Modalities Test (SDMT), and Trail Making Test (TMT)). The results showed that the peak torques of knee flexors (120°/s: p = 0.015, Hedges’g (g) = 1.84; 180°/s: p = 0.02, g = 2.06) and extensors (120°/s: p = 0.019, g = 1.63; 180°/s: p = 0.03, g = 2.01) increased in MG comparatively with PG. There was also a decrease in the sway area (bipedal stance) and mediolateral amplitude (unipedal stance) of the center of pressure in MG compared with PG in the eyes-open (both: p < 0.001; g = 4.32, g = 1.99, respectively) and eyes-closed (p = 0.0007, g = 1.31; p = 0.003, g = 1.79, respectively) conditions. The MG showed an increase in MoCA (p = 0.0006, g = 1.51) and SDMT (p = 0.02, g = 0.95) scores, as well as a decrease in HADS-Total score (p = 0.012, g = 1.06), TMT (p = 0.03, g = 0.91) and NHPT durations (p < 0.001, g = 2.36) comparatively with PG. Based on this study, the 12-week melatonin supplementation was effective in improving knee muscle strength, manual dexterity, static postural balance, mood, and cognition in multiple sclerosis patients. For clinical trial regsitration, this study was prospectively recorded in the Pan African Clinical Trial Registry (PACTR202007465309582).

Comparative Analysis of Physical Fitness in Aquatic and Terrestrial Environments Among Elderly Women.

(1) Background: Aging is associated with a progressive decline in physical capacity, which is further exacerbated by conditions such as arthritis and chronic joint pain. This study aimed to compare the effects of aquatic and land-based exercise on the functional fitness of older adult women. (2) Methods: Sixty older women (mean age 66.9 ± 3.8 years) participated in this study, divided into two groups: aquatic exercise and land-based exercise. Both groups completed functional fitness tests, including flexibility (Back Scratch and Chair Sit-and-Reach Tests), lower body strength (Chair Stand Test), and dynamic balance (8-Foot Up-and-Go Test). Statistical analyses compared group performance. (3) Results: Improvements in flexibility were observed in the aquatic group, with trends toward significance for the Back Scratch Test (-0.2 ± 1.0 cm vs. -2.0 ± 0.0 cm, p = 0.08) and the Chair Sit-and-Reach Test (2.87 ± 2.0 cm vs. 0.27 ± 1.0 cm, p = 0.07). No statistically significant differences were observed between the groups in measures of lower body strength (Chair Stand Test: 19.1 ± 4.47 reps vs. 18.97 ± 3.77 reps, p = 0.9) or dynamic balance (8-Foot Up-and-Go Test: 6.28 ± 6.2 s vs. 6.03 ± 5.83 s, p = 0.07). (4) Conclusions: Aquatic exercise showed greater improvements in flexibility, particularly in the upper and lower body, although these differences did not reach statistical significance. Both training modalities were equally effective in maintaining lower body strength and dynamic balance in older adult women. These findings support the inclusion of tailored exercise programs in aging populations to address specific functional needs.

Rehabilitation With Bridging Exercise In Stroke Patients: Systematic Review

Background: Stroke is a neurological disease that can result in weakness in part or all of the body, emphasizing the importance of early mobilization in post-stroke recovery. One of the fundamental physical exercises recommended is the bridging exercise. This article evaluates the impact of bridging exercises on stroke patients through a systematic review approach, focusing on their potential to improve rehabilitation outcomes. Methods: The methodology involved a systematic review of studies from 2020 to 2024, using journal databases such as Google Scholar, Science Direct, and PubMed. Keywords like "Bridging exercise," "Stroke," "Stroke patients," "Rehabilitation," "Muscle strength," and "Body balance" guided the search. Articles included in the review were in English and selected based on PRISMA guidelines, resulting in seven eligible studies for analysis. Results: The results of this review highlight that bridging exercises significantly improve muscle strength and body balance among stroke patients. The exercises demonstrated a positive influence on patients' rehabilitation progress, contributing to better physical and functional health outcomes. Conclusion: In conclusion, bridging exercises serve as an effective intervention in stroke rehabilitation, promoting early mobilization and improving post-stroke recovery. Encouraging stroke patients to incorporate these exercises into their rehabilitation routines could enhance overall health and functional capabilities.

Multi-functional AA6061 alloy hybrid composites via friction stir processing: tailoring properties with TiNi and ceramic nanoparticles

ABSTRACT This study presents a novel approach to developing hybrid aluminum matrix composites by combining the friction stir processing (FSP) of AA6061 with TiNi particles and secondary ceramic reinforcements (TaC, BN, Al2O3). This distinctive combination maximizes the properties of mechanical, tribological, and corrosion resistance. The FSP, when used in combination with TiNi particles, caused a marked reduction in grain size, especially in the presence of Al2O3, owing to enhanced dynamic recrystallization. Thus, the most promising mechanical characteristics among the composites were demonstrated by AA6061/TiNi+TaC, which is 50% higher than base alloy AA6061. Incorporating TiNi particles alone through FSP enhanced wear resistance by 16% and microhardness by 15.4%. Adding TaC nanoparticles further improved wear resistance by 65% and microhardness by 43.8%. BN nanoparticles provided the most significant wear resistance improvement (83% reduction) and a 35.1% increase in microhardness, while Al₂O₃ improved wear resistance by 29% and microhardness by 23.2%. The combination of FSP with TiNi and TaC nanoparticles offers a promising route to achieving a balance of high strength, stiffness, and corrosion resistance, while BN additions prioritize superior wear resistance and low friction.

Strong and Tough Self-Healing Elastomers via BTA-Mediated Microstructure and Metal-ligand Coordination.

Creating elastomers with high strength, toughness, and rapid self-healing remains a key challenge. These seemingly contradictory properties require innovative design strategies. Herein, a novel approach is proposed by simultaneously incorporating a unique triple hydrogen bond unit, benzene-1,3,5-tricarboxamide (BTA), and imidazole-Zn2+ dynamic coordination into the elastomer. The BTA forms rigid fibers through self-assembly via triple hydrogen bonding, inducing microphase separation that significantly enhances the material's properties. Hydrogen bonds and coordination interactions provide dynamic reversibility and self-healing, achieving a balance of strength, toughness, and healing capabilities. By varying the BTA content and the degree of coordination crosslinking, the elastomer's strength is tunable within 8.79-2.03MPa, and it boasts an impressive elongation at a break of up to 700%. Remarkably, it recovers 94.6% of its strength after being cut in half, facilitated by treatment with DMF at 70 °C for 24h. Furthermore, the integration of carbon nanotubes endows the material with resistance-sensing, enabling real-time monitoring of human movements. Overall, this study lays a theoretical foundation and introduces innovative concepts for the development of high-toughness self-healing elastomers.

Modification of mechanical and microstructural characteristics into Ti‐6Al‐4V alloy by thermal treatment

Purpose The purpose of this study is to analyze the titanium alloy under heat treated condition. Titanium alloy heat treatment, particularly Ti‐6Al‐4V alloy, has been an important field of study due to its wide variety of uses in the aerospace, automotive, and biomedical sectors. The mechanical characteristics of titanium alloys are heavily influenced by their microstructure. Cold‐rolled Ti‐alloys have strong bending and tensile strength due to extensive β‐phase precipitation on the α matrix. However, various heat treatment (HT) methods can affect the mechanical characteristics. The current study seeks to investigate the effects of various heat treatment procedures on the microstructural and mechanical changes of Ti‐6Al‐4V alloy, in order to achieve an optimal balance of strength, hardness, and ductility for a variety of real-world applications. Design/methodology/approach Three plates of Ti‐6Al‐4V alloy were heated above the β‐transus temperature for a certain period and then cooled via furnace, air, and sand. One extra plate was kept in ‘untreated’ condition and given name ‘as received’ plate. The three heat treated plates were evaluated and compared with ‘as received’ plate based on tensile strength, bending strength, hardness, and microstructural changes. Findings A considerable change in orientation of α and β was noted through optical microscopy upon heat treatment. The mechanical testing revealed that all the cooling methods adopted in the study have reduced the UTS and increased the YS of the plates. The ductility of the alloy was primarily enhanced by 'air cooling' and 'sand cooling' methods. Originality/value Notably, the hardness test findings indicated a significant drop in hardness for the ‘sand‐cooled’ sample. Furthermore, the ‘air cooled’ sample showed the maximum hardness due to the production of acicular α regions.

Tuning interfacial wettability in high‐entropy cemented carbides for enhanced mechanical performance

AbstractThis study investigated three newly developed high‐entropy cemented carbides (HECCs) with high‐entropy carbides (HECs) as the hard phase and Co as the binder. Accordingly, the interfacial wettability between HECs and Co was tuned by the changes in relative concentrations of the different metal components (e.g., W, Ta, and Ti) and C. Results demonstrate that the wettability between HECs and Co is dominated by the dissolution of HECs in Co, which determines the sintering behavior and hence the structure and performance of the materials. More specifically, the (W6Ta4Nb10Zr10Ti20)C50‐Co with lower W content has poorer interfacial wettability, leading to pores in the sintered HECC. The (W10Ta10Nb10Zr10Ti10)C50‐Co shows good interfacial wettability and strong resistance against grain boundary infiltration, owing to the formation of several atomic‐layer‐thick Co films between HEC grain boundaries. Reducing the C content facilitates the dissolution of HECs in Co, which can improve the interfacial wettability, but promotes the formation of η‐W3Co3C phase and embrittle the material. The (W10Ta10Nb10Zr10Ti10)C50‐Co with decent interfacial wettability exhibits a good balance of hardness (HV30 ∼1485), compressive strength (3316 MPa), and fracture toughness (10.9 MPa·m1/2). The work demonstrates a design strategy achieving optimized microstructure and mechanical performance in HECCs via tuning interfacial wettability.

Synergy of tensile strength and ductility in a novel additively manufactured Al-Mg-Mn-Er-Zr alloy with a trilevel equiaxed heterogeneous structure

ABSTRACT This study investigates a novel Al-Mg-Mn-Er-Zr alloy with high strength and elongation. The uneven distribution of L12-Al3Er and Al3(Er, Zr) phases in the molten pool structure results in a trilevel equiaxed heterogeneous structure in the alloy. The as-printed alloy exhibits various forms of Al3(Er, Zr) phases and Er-containing primary phases (such as Al3(Zr, Er)5), demonstrating an excellent combination of strength (ultimate tensile strength of 531 MPa, yield strength of 455 MPa) and elongation (fracture elongation of 27%). The strengthening mechanism and strain distribution behaviour of the heterogeneous structure are explored to understand the alloy's elongation and strength mechanism. The large equiaxed grains concentrated in the centre of the molten pool contribute to high elongation, while heterogeneous deformation-induced (HDI) strengthening caused by heterogeneous grains increases the strength. The ultrafine grains at the molten pool boundaries ensure that strength remains at a high level, achieving a good balance of strength and elongation.