Search Results (82,439)

Carbon nanotube yarns (CNTYs) have received more consideration recently due to their excellent specific mechanical, electrical and thermal properties, making them promising materials for different applications. Until now, the axial properties of the yarn have been thoroughly investigated; however, the transverse or radial properties, orthogonal to the fiber axis, remain relatively unknown due to the challenges associated with their measurement. In this study, the transverse or radial response of the CNTY including its elastic modulus was determined using Atomic Force Microscopy (AFM) and Raman Spectroscopy. Determining transverse properties in fibrous materials presents challenges owing to their geometry, inherent anisotropy, whereby mechanical characteristics exhibit directional disparities; i.e., the properties in the transverse direction may be several orders of magnitude smaller than those in the axial direction. To overcome these difficulties, AFM was utilized to perform nanoindentation experiments, where a tipless flexible cantilever probe was used to apply a controlled force to the CNTY surface. The resulting indentation depth was then analyzed to determine the transversal elastic modulus. Preliminary findings indicate that the transverse elastic modulus of the CNTYs ranges from 10–54 kPa for strain levels below 3%. Complementary Raman spectroscopy provided insight into the bulk-scale mechanical behavior of CNTYs. Incremental compressive loading between microscope slides induced nonlinear upshifts in the 2D Raman band (from ~2686.6 to 2691.4 cm⁻¹), indicating nanoscale tube realignment, inter-tube densification, and compaction. From lateral diameter measurements under load, a stress–strain curve was constructed, revealing three distinct regimes: one with an initial elastic modulus of 3.12 MPa (0.3–11.2% strain), another one with an elastic modulus increasing to 8.46 MPa (11.2–14.4%), and finally one with an elastic modulus peaking at 16.86 MPa beyond 14.4% strain. Together, these methods delineate the hierarchical and anisotropic nature of CNTYs, validating the importance of multiscale mechanical characterization for their deployment in piezoresistive sensors and multifunctional composites. This study establishes a robust framework for quantifying the transverse mechanical response of CNTYs. Full article

Background: Chronic Obstructive Pulmonary Disease (COPD) is a common condition that can cause dyspnea, pain, and biomechanical-postural alterations, especially when overlapping with Myofascial Pain Syndrome (MPS). Balneological rehabilitation medicine can help manage COPD and MPS, but it lacks homogeneity and detailed descriptions of effective therapeutic protocols. Therefore, we conducted a case series to preliminarily evaluate the clinical effects of a detailed and codified approach, called Bio-Physico-Metric Integrated Thermal Care (BPM-ITC), for COPD+MPS. Methods: 10 patients were observed while undergoing 20 sessions of BPM-ITC in 4 weeks. Patients were assessed before and after the protocol using the Medical Research Council (MRC) dyspnea scale, Numeric Pain Rating Scale (NPRS), and the Bio-Postural Questionnaire (BPQ) for bio-physical health status. Treatments included manual therapy of key myofascial trigger points combined with crenotherapy, steam inhalations, mud therapy, vascular path, and water-based motor re-education. Results: At the end of the protocol, clinically relevant improvements were observed in almost all parameters considered in single observed cases; overall statistical analysis of the data highlighted significant positive effects in concomitance with the BPM-ITC protocol. Conclusions: The BPM-ITC protocol was followed by significant clinical improvements in the observed cases, suggesting its potential as a complementary approach for COPD+MPS. Further studies on this topic are recommended. Full article

In this study, rice-husk fiber (RHF) extracted via alkali hydrolysis was used as a reinforcing material (0–10 wt%) in a pectin-sodium alginate (PE/SA) matrix to develop biofilms by the casting method. These biofilms were characterized by using FTIR, XRD, TGA, and DSC. The thickness, moisture content, water solubility, swelling behavior, water-contact angle, water-vapor permeability, optical transparency, and mechanical properties of biofilms were investigated. It was observed that the PE/SA/RHF film loaded with 5% RHF had better visual attributes, and a further increase in reinforcement was not found to be as favorable. The addition of 10 wt% RHF significantly enhanced the thickness from 0.094 to 0.127 mm, water solubility from 49.25 to 56.13%, water-contact angle from 48.4 to 62.6°, and tensile strength from 4.17 to 10.23 MPa. However, decreases in water-vapor permeability from 1.94 × 10⁻⁹ to 1.32 × 10⁻⁹ g·m⁻¹·Pa⁻¹·s⁻¹ and in elongation at break from 19.24 to 2.87% were observed in the biofilms. Structurally, FTIR confirmed intermolecular hydrogen bonding between components. XRD revealed that the films remained predominantly amorphous, without significant crystalline alterations. Furthermore, thermal stability improved with the addition of RHF. Finally, these PE/SA/RHF composite films may be potential eco-friendly biodegradable packaging candidates for food industry applications. Full article

The commercialization of poly(butylene succinate-co-adipate) (PBSA), a biodegradable and potentially fully biobased random copolyester, is still ongoing. Due to its high relevance as mono material or as blend component in flexible film applications, a sound understanding of compounding, further processing and film properties is necessary. In this work, PBSA, poly (lactic acid) (PLA) and blends at three different compositions thereof were processed into flat films and blown films, respectively. Investigating the films with X-ray diffraction (XRD), multivariate confocal Raman microscopy (CRM) and scanning electron microscopy (SEM) revealed the semicrystalline order as well as the blend morphology. While PBSA is semicrystalline, PLA remains amorphous after the processing step. As imaged by CRM, flat films exhibit lamellar-like domains formed during uniaxial stretching and rapid cooling, whereas blown films show no pronounced preferential orientation. Tensile tests in both the machine and transverse directions demonstrate the versatility of PBSA and its blends in spanning a wide range of mechanical strength and flexibility, covering and partly exceeding the stiffness and strength ranges typically reported for commodity polyolefins while exhibiting reduced ductility. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) provide further insights into the thermal properties of the pure and blend materials. Full article

Per- and polyfluoroalkyl substances (PFAS) constitute a large and chemically diverse class of synthetic compounds characterized by one or more fully fluorinated methyl or methylene groups. Many PFAS are toxic, environmentally persistent, bioaccumulative, and highly mobile, resulting in widespread contamination and biological exposure. Across taxa PFAS exhibit affinity for proteins and preferentially accumulates in protein-rich, highly perfused tissues. Protein binding critically influences PFAS distribution, bioaccumulation, toxicity, and elimination. A variety of different approaches for determining bind affinity have existed for decades; however, depending on experimental conditions, calculated affinities can vary over multiple orders of magnitude which limits comparison of protein–PFAS binding affinities across studies and across PFAS chemical space. Addressing this limitation requires robust and standardized experimental platforms capable of rapidly generating quantitative binding data. Among the most important targets is serum albumin—the principal transport protein in vertebrate blood—which plays a central role in governing PFAS toxicokinetics. This review summarizes current methodologies for measuring protein–PFAS binding affinities, evaluates the strengths and limitations of each approach, synthesizes the existing literature on serum albumin–PFAS interactions, and highlights differential scanning fluorimetry as a rapid, reproducible, and sensitive technique for in vitro assessment of relative protein–PFAS binding. Full article

Electromagnetic field-based stimulation has emerged as a promising noninvasive approach for enhancing bone fracture healing. Beyond conventional pulsed electromagnetic field (PEMF) therapies employing spatially uniform fields, dielectrophoretic-force-based (DEPF) stimulation exploits electromagnetic field non-uniformities to induce localized interactions to enhance fracture healing. However, the thermal behavior associated with DEPF-driven PEMF exposure in the presence of metallic orthopedic implants remains largely unexplored. In this study, the thermal response of tissue-like tibia phantoms with and without metallic implants is investigated using an integrated experimental and numerical framework. A custom-designed conical coil is employed to generate non-uniform DEPF excitation capable of affecting the fracture site. Surface temperature evolution is measured using infrared thermal imaging, while electromagnetic power absorption is quantified through specific absorption rate (SAR)-based thermal measurement coupled with a bio-heat formulation. Anatomically realistic tibia phantoms reconstructed from computed tomography data are fabricated via a 3D printer to represent clinically relevant fracture configurations. Experimental results show that the metallic implant exhibits a rapid temperature increase of approximately $0.4 °\mathrm{C}$ within the first few minutes of exposure, followed by thermal stabilization, corresponding to an effective absorbed power of ${\mathrm{SAR}}_{\mathrm{eff},\mathrm{implant}}\approx 2.2 \mathrm{W}/\mathrm{kg}$ inferred from the initial temperature slope. In contrast, the non-conductive resin phantom displays a temperature rise of only $0.05 °\mathrm{C}$ over the same interval, yielding ${\mathrm{SAR}}_{\mathrm{eff},\mathrm{resin}}\approx 0.8 \mathrm{W}/\mathrm{kg}$. These findings demonstrate that implant-related eddy-current losses dominate localized heating under DEPF excitation, while tissue-like media remain weakly affected. This work provides SAR-based experimental evaluation of DEPF stimulation in implanted tibia fracture models, offering new insight into implant-induced electromagnetic heating and its implications for the safety and optimization of DEPF-based bone-healing therapies. Full article

Calcium oxalate (CaOx) crystals in plants can form naturally within their idioblasts but may also be induced by other factors, such as environmental pollution. Here, we report qualitative and semiquantitative results obtained using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) from two experiments in which tomato seedlings were moderately irrigated with Sulfamethoxazole (SMX) and Amoxicillin (AMX) solutions (0.25 mM). Abundant prismatic CaOx co-crystals appeared on the leaf surface induced by these two antibiotics compared to the distilled water (DW) control. Applying a non-thermal plasma (NTP) treatment for 20 min (T20) to the SMX initial solution led to a dramatic suppression of these crystals, with a shift toward spherical structures. Furthermore, the investigation into the composition of both crystal types, indicated different percentual levels of O, C, Ca, K, Mg, S, and Mn as main constituent minerals involved in crystal formation. However, crystal morphology was affected by each applied experimental condition, while detecting their constituent elements depended on their mineral homogeneity at the micro- or macro-field scales. Although both antibiotics induced crystal formation and T20 phenotypically reduced the abundance of the acicular–prismatic crystals by removing the effects of SMX, their mode of action has not yet been clarified. Full article

Metal additive manufacturing (AM) offers unprecedented opportunities to fabricate complex, lightweight metallic components, yet its practical deployment remains fundamentally constrained by defects arising from rapid melting and solidification. Cyclic thermal transients generate cracks, pores, residual stresses, and lack-of-fusion regions, undermining mechanical performance and reliability. Ultrasonic field-assisted laser-based additive manufacturing (UF-LBAM) has emerged as a powerful approach to manipulate melt pool dynamics and suppress defect formation. Nevertheless, the governing physical mechanisms remain poorly understood, particularly under highly non-equilibrium ultrasonic excitation, where acoustic pressure oscillations, melt convection, cavitation, and solidification are intricately coupled across multiple temporal and spatial scales. Here, we provide a systematic review of X-ray based fundamental studies in UF-LBAM and the diverse applications of machine learning (ML), detailing the literature selection criteria and methodology. We highlight advances spanning synchrotron X-ray revealed physical phenomena, ML-driven real-time monitoring and defect prediction, and pathways toward industrial implementation. Critical challenges persist, including fundamental physics gaps, transferability of ML models across alloy systems, and real-time control limitations. We further identify promising directions for the field, such as physics-informed models, multimodal diagnostics, and closed-loop control, which together promise to unlock the full potential of UF-LBAM for high-performance metal component fabrication. Full article

Ammonia has emerged as a strategically advantageous hydrogen carrier; however, its efficient decomposition using conventional solid catalysts remains technically challenging from an industrial standpoint, particularly in terms of long-term stability and large-scale implementation. In this study, we propose a strategy for ammonia cracking by utilizing Sn-based molten metal alloys in a bubble column reactor, which provides a sintering-resistant and thermally efficient catalytic platform. Among various candidate transition metals, the Sn-Co alloy exhibited the most superior catalytic performance, demonstrating a significant reduction in the apparent activation energy to 52.6 kJ/mol. To the best of our knowledge, this study provides the first experimental evidence of the catalytic role of molten metals in the ammonia decomposition process. Structural characterization confirmed that the molten alloy maintains its metallic state without the formation of nitrides, verifying the function of the molten metal as an active catalyst rather than a sacrificial reagent. This work offers a new catalytic approach that addresses the requirements for the commercialization of ammonia cracking through improved scalability and chemical durability. Full article

To address the capacity decay of NCM811 caused by microcracks and cation disorder during cycling, La, Al, and F tri-doped micron-sized single-crystal NCM811 material with a LiNbO₃ coating was synthesized via a facile co-solvent method. Using a mixed glucose–urea thermal solution as the reaction medium, metal salts were incorporated, followed by step-wise sintering, ball-milling, heat treatment, and wet-chemical coating. This approach enables atomic-level precursor mixing and ensures homogeneous element distribution. La³⁺ enlarges the lithium layer spacing to enhance ion diffusion and Al³⁺ suppresses Ni³⁺ reduction to Ni²⁺, mitigating cation mixing and improving conductivity, while F⁻ stabilizes the crystal structure via its strong electronegativity. The LiNbO₃ coating protects the interface from electrolyte attack, and the single-crystal morphology effectively suppresses microcracking. Compared to unmodified single-crystal NCM811 prepared identically, the modified material exhibits reduced cation disorder, improved crystallinity, and superior thermal stability. Electrochemical tests in half-cells with 1 M LiPF₆/(EC/EMC/DMC) electrolyte (2.8–4.3 V) show an initial discharge capacity of 208.32 mAh/g at 0.1 C and 194.05 mAh/g at 1 C. After 200 cycles at 1 C, the capacity retention remains at 92.21%, exceeding the market average. Rate performance is also notably enhanced, with the 5 C discharge capacity increasing from 141.12 mAh/g (unmodified) to 166.81 mAh/g, demonstrating improved kinetics and structural stability. Full article

The fracture behavior of Beishan granite is a critical scientific basis for evaluating and ensuring the long-term safety of geological repositories for high-level radioactive waste under extreme thermal–mechanical conditions. With increasing emphasis on climate-resilient infrastructure, understanding the mechanical response of deep geological materials under cyclic loading and simulating long-term environmental conditions are essential for sustainable engineering management. Previous studies have predominantly concentrated on the fracture characteristics under static loading tests, with limited research conducted on the characteristic parameters of acoustic emission (AE) during cyclic loading and the morphology of fractures post-failure. Contributing to the field of resilient infrastructure, this paper presents static and cyclic loading tests using MTS815 equipment on Beishan deep granite (CCNBD type). To determine the rock fracture toughness of mode I and fracture roughness, static loading and cyclic loading tests were conducted using MTS815 equipment with Beishan deep granite (CCNBD type) as the subject of study. AE and 3D laser scanning were employed to acquire the characteristic parameters of acoustic emission (AE) during loading and the morphology of fracture surfaces after failure in the specimens. The results revealed that CCNBD specimens demonstrated pronounced brittle tensile failure under static and cyclic loading conditions. The rock fracture toughness obtained in static tests was 1.180 MPa·m^1/2, whereas under cyclic loading, it was 1.153 MPa·m^1/2. In comparison to static loading, cyclic loading led to a greater accumulation of microcracks inside the specimens, resulting in a 9.8% increase in the length of the fracture process zone. A 57.5% increase in section roughness (fractal dimension) was observed after the failure of the specimen in comparison to static loading. Full article

CAD/CAM polymer-based dental materials are increasingly used as metal-free alternatives for fixed and implant-supported restorations. High-performance polymers such as polyetheretherketone (PEEK), fiber-reinforced composites, and graphene-reinforced polymers have been introduced to improve material stability; however, evidence regarding the effects of thermal aging on their physicochemical and biological properties remains limited. In this study, PEEK, a fiber-reinforced composite (FRC), and a graphene-reinforced PMMA-based polymer (G-CAM) were evaluated. Twenty-seven disc-shaped specimens (10 × 2 mm; n = 9 per material) were fabricated and subjected to 10,000 thermal cycles between 5 and 55 °C. Color change (ΔE₀₀), surface roughness (Ra), and Vickers microhardness (VHN) were measured before and after aging. Chemical stability was assessed using FTIR and Raman spectroscopy, surface morphology by SEM analysis, and biological safety by cytotoxicity testing. Material-dependent differences were observed in color stability, surface roughness, and microhardness after thermal aging (p < 0.05). Microhardness decreased in the fiber-reinforced and graphene-reinforced materials, whereas PEEK showed no significant change. Spectroscopic analyses indicated preserved chemical structure, and all materials demonstrated acceptable cytocompatibility. Thermal aging influenced material behavior while chemical stability and biological safety were maintained, highlighting the importance of considering aging behavior during material selection for prosthetic restorations. Full article

Mechanochromism is a phenomenon in which mechanical stimuli change the optical properties of a material, such as its color and emission properties. Various materials exhibiting this behavior have been intensively studied. Mechanochromic materials that exploit liquid crystals have been previously reported. Using liquid crystals, properties different from those of conventional materials, such as anisotropic response and multicolored luminescence due to intermediate aggregation phase stabilization, can be expected. Recently, we reported the preparation and evaluation of the optical properties of liquid-crystalline mechanochromic dyes with cholesterol terminals. The dyes formed gels in some solvents, changed their emission color, and exhibited a friable response without reaching a crystalline state. In addition, film-forming properties, processability, and responsiveness were improved in thin films mixed with polymers. However, the mechanical and thermal stabilities of the gels were low. In this study, a compound similar to the polymerizable unit was synthesized to produce tougher gels. In addition, triblock polymers with a mechanoresponsive dye in the hard segment were synthesized. The xerogel film prepared from the monomer showed an irreversible blue shift in photoluminescent color by mechanical grinding and also exhibited linearly polarized photoluminescence by uniaxial grinding due to force-induced alignment. On the other hand, the xerogel film prepared from the triblock copolymer showed a blue shift in photoluminescent color that can approximately revert to the initial state by thermal annealing, though it showed no anisotropy by uniaxial grinding, indicating that polymerization partially preserves mechanical responsiveness. Full article

Thin-walled laminated cooling plates integrate internal channels and pin-fin cores, producing reduced and spatially non-uniform stiffness that changes welding restraint and distortion. This study investigates stiffness-controlled plastic-strain evolution in laser butt welding of GH3230 laminated plates, with geometrically identical solid plates as reference. A coupled heat-transfer and thermo-mechanical finite element model was developed in MSC Marc using a composite Gaussian surface–volumetric moving heat source and temperature-dependent properties. The thermal solution was validated against near-weld thermal cycles and fusion geometry; mechanical predictions were evaluated by CMM distortion and residual-stress measurements. Both structures show comparable residual-stress magnitudes and spatial trends, indicating that residual stress is governed mainly by the local weld thermal gradient. In contrast, the laminated plate exhibits larger angular/bending distortion. Simulations show that, although the plastic-strain pattern is similar, the laminated plate develops higher peak plastic strain confined to a narrower band near the weld, with the transverse plastic strain dominating. Plastic strain–temperature paths reveal continued transverse plastic-strain accumulation during cooling with limited recovery, consistent with restraint redistribution induced by stiffness non-uniformity. An equivalent restraint–stiffness spring model explains this “narrower-but-stronger” plastic zone and links stiffness to yielding and residual plastic-strain magnitude, supporting distortion prediction and stiffness-informed control of welded laminated cooling plates. Full article

Wood is the quintessential material for musical instruments due to its superior acoustic properties. However, its inherent susceptibility to environmental degradation—including moisture-induced dimensional changes, photodegradation, and biological attack—presents a fundamental challenge that treatment strategies must address. This critical review systematically examines recent advances in wood modification and surface protection technologies for musical instruments, encompassing chemical and thermal modification, protective coatings, physical densification, and biological treatments. Drawing on studies published over the past two decades, this review synthesizes current knowledge on how these interventions affect wood’s acoustic performance, dimensional stability, mechanical integrity, and long-term durability. A central finding is that treatment outcomes are highly species-specific and involve complex performance trade-offs: acoustic optimization often comes at the expense of mechanical strength or dimensional stability, and the optimal solution varies depending on the functional requirements of specific instrument components (e.g., soundboards versus fingerboards). Emerging bio-based and nanocomposite coatings show promise for enhancing environmental resistance, but their acoustic implications remain largely unexplored. Furthermore, most research remains at the laboratory scale, with limited validation on full instruments and a notable absence of long-term performance data under natural aging conditions. To advance the field from empirical trial-and-error toward predictive, knowledge-based design, this review identifies three priority areas for future research: (1) establishing cross-scale “treatment-structure-performance” correlation models that bridge molecular-level modifications to instrument-level acoustic outcomes; (2) developing intelligently engineered surface systems capable of multi-objective synergistic optimization; and (3) creating comprehensive assessment standards that encompass acoustics, durability, and sustainability. By systematically synthesizing current knowledge and identifying critical gaps, this review provides a foundation for more targeted, interdisciplinary research in instrument wood protection. Full article