Search Results (4,142)

Plastics represent one of the biggest challenges related to the circular economy (CE) and sustainable development goals (SDGs). In this study, both the virgin and mechanically recycled versions of three traditional petroleum-based polymers, polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET), are compared. For that, an investigation of the different mechanical, chemical and thermal properties was conducted. Additionally, the life cycle eco-indicators were studied for each case. Finally, correlations between all of the factors were studied in order to get a more comprehensive understanding of how the properties influence one another. Full article

The development of straightforward and efficient strategies for the preparation of polymer-functionalized mesoporous silica remains an important challenge in the design of advanced hybrid materials. Herein, we report a novel and simplified approach to the covalent functionalization of mesoporous silica particles (MSP) with poly(2-ethyl-2-oxazoline) (PEtOx), based on the direct termination of living cationic polymer chains by amino groups immobilized on the silica surface. In contrast to conventional grafting-to methods, the proposed strategy eliminates the need for polymer end-group functionalization while avoiding the synthetic complexity associated with surface-initiated polymerization. Well-defined PEtOx chains with number-average molar masses of 5000 and 7500 g mol⁻¹ were synthesized by cationic ring-opening polymerization (CROP) and subsequently grafted onto amino-functionalized MSP. Successful covalent immobilization of the polymer was confirmed by Fourier-transform infrared spectroscopy (FT-IR), elemental analysis, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), contact angle measurements, and nitrogen adsorption–desorption studies. The modification preserved the ordered mesoporous architecture while increasing particle hydrophilicity and decreasing the specific surface area and pore volume due to polymer incorporation. Shorter polymer chains exhibited higher grafting efficiency than higher-molar-mass analog, indicating that steric hindrance is an important factor influencing the grafting process. The presented methodology provides a versatile and experimentally accessible platform for the preparation of well-defined poly(2-oxazoline)-functionalized mesoporous silica with tunable physicochemical properties. Owing to the combination of a porous inorganic framework and a polymer shell, the obtained hybrid materials represent promising candidates for drug delivery, adsorption technologies, and other advanced biomedical and environmental applications. Full article

Material extrusion 3D printing has been widely used in industrial, educational and residential environments. However, the associated emissions and exposure health impacts need to be evaluated, especially for the new and emerging filament materials. This study characterized particle and chemical emissions from 3D printing using five different metal composite filaments, which contain over 90% (by weight) of metal powder blended with polymer binders. The emission characterization was conducted using an exposure chamber following a standard testing method. Real-time particle measurements showed that particle emission rates ranged from 8 × 10⁹ to 2 × 10¹¹ particles/h for particle number and 200 to 1400 µg/h for particle mass. Over 98% of the emitted particles were smaller than 1 µm, which poses an inhalation hazard. Inductively coupled plasma–mass spectrometry analysis detected manganese, copper, zinc, and selenium in emitted particles from all filaments. However, metal powder in raw filaments tended not to be transferred into particle emissions, resulting in the total metals (and metalloids) accounting for 0.07% to 0.95% of emitted particle mass. Sorbent tube sampling and analytical analyses showed various volatile organic compounds emitted during printing, including hydrocarbons, alcohols, aldehydes, and aromatic compounds. Overall, metal composite filaments generated lower levels of volatile organic compounds (VOCs) compared to thermoplastic polymer filaments; in addition, the emitted VOC compositions differed. Organic chemicals associated with metal composite filament emissions included formaldehyde, benzaldehyde, acetaldehyde, naphthalene, and trimethylbenzene, exposure to which may cause irritations or other adverse health impacts. This study estimated personal exposure to hazardous components assuming a person is close to the printer with low ventilation to represent an acute worst-case exposure scenario. Modeled personal exposure to emissions showed potential exceedances of exposure to fine (PM_2.5) and coarse (PM₁₀) particulate matter, arsenic, manganese, formaldehyde, caprolactam, acetaldehyde, and naphthalene compared to reference levels. A modeled office room with ventilation showed reduced exposure levels by up to two orders of magnitude, assuming the same emission source. Users can avoid close proximity to an operating printer and increase dilution through larger room volumes and higher air change rates to reduce potential inhalation exposures at given printing conditions. Full article

A low-voltage alternating current (AC) field (20 V peak-to-peak, 1 kHz) was superimposed on a conventional direct current (DC) electrospinning configuration in order to test whether the shape of that perturbation measurably alters fiber formation. A function generator delivered sinusoidal, pulsed (square), ramp and arbitrary (noise) waveforms to a foil-covered flat collector, while a standard DC high-voltage source (20 kV) drove the jet from the spinneret. Polyvinylpyrrolidone (PVP) nanofibers were characterized by scanning electron microscopy (SEM), fiber-diameter distribution analysis (FIJI/ImageJ), quantitative orientation analysis and contact profilometry. One-way analysis of variance across the six conditions was significant (F(5.594) = 5.56, p = 5.1 × 10⁻⁵) but the associated effect size was small (η² = 0.045). Relative to the connected control (237 ± 52 nm), the ramp (205.5 ± 43.9 nm), noise (201.3 ± 48.6 nm) and pulse (212.6 ± 70.0 nm) waveforms yielded significantly finer fibers (Tukey HSD, p = 0.0008, 0.0001 and 0.022, respectively); relative to the grounded control (215 ± 47 nm), no waveform reached significance. The ramp waveform produced the narrowest diameter distribution but, unexpectedly, the roughest mat of the four AC conditions (Ra = 1.95 µm against 0.74 µm for the grounded control), while the noise waveform gave both the smallest mean diameter and the smoothest mat (Ra = 0.61 µm); with a single profile per scan direction, these roughness values are descriptive rather than statistically compared. Quantitative orientation analysis using two independent estimators (structure tensor and fast Fourier transform) returned Herman orientation factors of S ≤ 0.13 for every condition, against S = 0.81 for a partially aligned reference population: no condition exceeded the isotropic noise floor of the FFT estimator (S95 = 0.141), and the three conditions that marginally exceeded the structure-tensor floor (S95 = 0.104) included the connected control, which received no oscillating signal. No waveform, including the pulsed waveform, produced fiber alignment attributable to the AC field. The applied AC amplitude corresponds to approximately 0.05% of the DC voltage, and the associated oscillating field (±50 V m⁻¹) is approximately three orders of magnitude smaller than the mean DC field (~1 × 10⁵ V m⁻¹); the electrohydrodynamic mechanisms discussed here are therefore presented as hypotheses requiring direct measurement rather than as established explanations. Within these limits, low-voltage waveform modulation is a simple, safe and retrofittable route to modest control of nanofiber diameter and mat uniformity in a single-polymer system, but it does not induce fiber alignment. Full article

Diabetic chronic wounds face multiple intractable healing obstacles including sustained inflammation, severe infection, insufficient angiogenesis and defective collagen deposition. Current dressings fail to simultaneously relieve all these pathological defects. Herein, we constructed a carrier-free binary self-assembled Glycyrrhizic acid monoammonium salt–Berberine (GB) hydrogel composed of berberine and glycyrrhizic acid monoammonium salt, which forms interconnected nanofiber networks via one-pot thermally assisted small-molecule co-assembly without chemical crosslinking or exogenous polymer carriers. Relying on intermolecular non-covalent interactions, this single supramolecular material integrates anti-inflammatory, broad-spectrum antibacterial, pro-angiogenic, and collagen-regenerative multifunctions, which simultaneously ameliorates multiple core pathological obstacles of diabetic wounds within one formulation. We systematically characterized its physicochemical features, biocompatibility, and antibacterial and anti-inflammatory activities, as well as in vivo wound repair performance. This hydrogel formed uniform nanofibrous architectures with favorable viscoelastic properties and pH-dependent sustained release. In vitro assays verified its outstanding biosafety, broad-spectrum bacteriostasis against Escherichia coli and Staphylococcus aureus, and potent inhibitory effects on pro-inflammatory cytokines TNF-α and IL-6, with bacterial inhibition rates reaching ~88% against E. coli and ~70% against S. aureus. In diabetic mouse full-thickness infected wound models, the GB hydrogel simultaneously alleviated local inflammation, accelerated wound closure and facilitated ordered collagen deposition and mature microvessel formation, achieving a 73.10% wound closure rate at day 7 and 58.01% collagen deposition fraction at day 14, thus exhibiting equivalent or superior repair capacity compared with commercial hydrogel dressings. This carrier-free supramolecular system based on natural herbal small molecules provides a safe, convenient, and integrated therapeutic strategy for diabetic infected chronic wounds, with promising clinical translation potential. Full article

Background/Objectives: Microplastics (MPs) are increasingly reported in human reproductive tissues and fluids, but detection alone does not establish tissue injury or disease. Recent reviews have synthesised occurrence, reproductive toxicity, placental transfer, fertility, and pregnancy outcomes. The unresolved problem is that occurrence, model-response, lesion-comparison, clinical-association, and causal evidence are not interchangeable. This review asks what minimum evidence is required for an MP finding in the female genital tract (FGT) or fetoplacental continuum to become lesion-relevant and where inference must stop. Methods: We performed a critical narrative search of PubMed, Scopus, Web of Science, ScienceDirect, and Google Scholar from database inception through 10 July 2026. The final synthesis comprised 59 sources: 28 primary studies, 24 reviews or systematic syntheses, and 7 regulatory, consensus, or professional-guidance documents.. Methodological recommendations were graded as claim-essential, context-dependent, or exploratory and as routine, specialised, or research-intensive. Results: The distinct contribution is an FGT-specific mechanistic and claim-to-evidence architecture rather than another environmental or reproductive-toxicity catalogue. We propose an ordered, claim-calibrated evidence ladder linking external exposure, internal dose, reproductive-fluid burden, spatial localisation, lesion response, and clinically annotated phenotype. The framework specifies the minimum evidence for occurrence, localisation, lesion, clinical, and causal claims and provides explicit stopping and downgrading rules rather than treating all desirable measurements as mandatory. The FGT Lesion Atlas is a compartment-by-compartment map of prioritised, non-exhaustive endpoints and sampling requirements. The FGT Lesionome is a cross-compartment synthesis of recurring barrier-receptivity, stromal-fibrotic, vascular-perfusion, immune-microbiome, endocrine-steroidogenic, and particle-cargo axes. An integrated hypothesis-generating pathway links systemic or local exposure, internal and target-compartment burden, physicochemical conditioning in reproductive-fluid microenvironments, particle or particle-associated-constituent interaction with compartment-specific cells and matrices, the six response axes, physiological dysfunction, and clinically annotated outcomes. A reproductive-fluid model, an assisted-reproductive-technology sentinel sequence, and an FGT Microplastic Pathology Reporting Checklist rank study elements by evidentiary necessity, feasibility, and interpretive consequence. Conclusions: The framework is hypothesis-generating, not a validated causal map or a universal core outcome set. It separates essential validity safeguards from context-dependent best practices and exploratory endpoints. Human reproductive and fetoplacental disease causation remains unproven without contamination-controlled sampling, polymer confirmation, spatial co-localisation with lesions, temporality, exposure-response assessment, confounder control, replication, and appropriately powered, temporally informative clinical outcomes. Full article

Dilute-solution properties are important sources of information on the structure of macromolecules. Analyzing experimental data and extracting information on structural properties require theoretical and computational resources. The resources needed to study rigid particles are manageable; however, studying flexible particles is more challenging. This is because, unlike rigid bodies, and as a consequence of the conformational variability arising from flexibility, flexible particles do not have a definite size and shape. In addition to their overall translational and rotational Brownian motion, the dynamics of flexible particles in solution has an internal component: size/shape conformational fluctuations. In order to facilitate the study of flexible macromolecule hydrodynamics, we have implemented existing theories within several computer programs. MONTEHYDRO combines Monte Carlo simulations based on the importance-sampling algorithm to generate conformations from which, in addition to conformational quantities, the hydrodynamic properties of flexible particles can be obtained using rigid-body treatment. SIMUFLEX is a suite based on a Brownian dynamics simulation of macromolecules, comprising BROWFLEX, for the generation of trajectories, and ANAFLEX, for the calculation of static and time-dependent properties as well as the simulation of single-particle events. In this paper, we present some concepts which are fundamental to the methods implemented in those computational tools, as well as examples of their utilization in various biomacromolecule applications, with a particular emphasis on double-stranded DNA in various cases: coarse-grained double-helical models for moderately short DNA; the worm-like model treatment of DNA over an extremely wide range of sizes (from 8 to 200,000 base pairs); and the problem of the anomalous rotational-speed dependence of the sedimentation coefficient of very long DNA. SIMUFLEX has also been particularly useful for studying intrinsically partially disordered proteins, whose structure comprises both ordered, globular domains as well as flexible tail and linker chains. To illustrate applications in the field of synthetic polymers, we describe a study on dendrimers, with aspects related to drug delivery in targeted therapies. Full article

The study presents the results of experimental investigations into hybrid additive–subtractive manufacturing of lightweight PLA fixtures with gyroid internal structures. The proposed manufacturing approach combines FFF (Fused Filament Fabrication) printing with finish CNC milling in order to improve the dimensional accuracy, surface quality, and functional performance of polymer components intended for rapid tooling and functional prototyping applications. Test specimens with gyroid infill densities of 30% and 60% were manufactured from PLA material and subsequently subjected to finish milling under various cutting conditions. Particular attention was paid to the influence of cutting speed and feed per tooth on surface integrity, dimensional stability, and thermal effects occurring during machining. Maintaining the process temperature below the glass transition range of PLA (approximately 50 °C–60 °C) was identified as a critical factor for minimizing deformation and preserving geometric accuracy. The obtained results demonstrate that hybrid FFF-CNC processing enables the fabrication of lightweight yet sufficiently stiff fixtures characterized by improved surface roughness and high dimensional precision. The application of gyroid internal structures significantly reduces component mass while maintaining adequate mechanical rigidity. Moreover, the milled reference surfaces ensure precise positioning and repeatable geometric basing of cooperating machine and robotic assembly elements. The proposed hybrid manufacturing approach shows considerable potential for industrial implementation, particularly in the production of customized positioning fixtures, jigs, and functional tooling components used in automated assembly systems and rapid tooling applications. Full article

To address the technical bottleneck of the trade-off between fluidity and anti-dispersion performance in traditional underwater anti-dispersion cement pastes, this paper performs composite modification on the paste using polyacrylate (PAE) emulsion and nonionic waterborne epoxy resin (NEP) compounded with silica fume. The results show that both polymer components improve paste fluidity, whereas the silica-fume-free mixtures exhibit pronounced composition-dependent fluctuations in fluidity. Silica fume improves the stability of the paste’s fresh-state behavior but adversely affects its fluidity. Within the investigated dosage ranges, increasing the NEP dosage generally reduced turbidity and improved underwater anti-dispersion performance, whereas increasing the PAE dosage produced the opposite trend; silica fume exhibited a dosage-dependent effect, with an appropriate dosage contributing to lower turbidity. Experiments were conducted based on the Box–Behnken response surface methodology to establish second-order regression prediction models for fluidity and underwater anti-dispersion performance respectively. The RSM analysis identified model-derived candidate dosage ranges of 15–25% PAE solids, 9–15% NEP, and approximately 5–15% silica fume by cement mass. An independent validation batch prepared at the predicted optimum of 15.54% PAE solids, 13.69% NEP, and 4.95% silica fume exhibited a fluidity of 142 mm and a turbidity of 148 NTU. The validation results support the local predictive reliability of the models and confirm that the candidate composition satisfies the predefined fresh-state fluidity and turbidity criteria; its hardened-state and engineering-scale performance remains to be evaluated. Full article

Hollow filament-wound glass fiber-reinforced polymer (GFRP) tubes are known for their high specific strength, corrosion resistance, and structural efficiency. The nonlinear flexural response of these structures is controlled by the interaction of material and stability mechanisms, which are not well-captured by traditional linear sectional approaches. In this paper, a nonlinear sectional analytical model is proposed to determine the flexural response and the corresponding failure modes of hollow filament-wound GFRP tubes subjected to monotonic four-point bending. The formulation combines Euler–Bernoulli beam kinematics, layered numerical integration of the annular cross-section, asymmetric nonlinear tensile and compressive constitutive relations, iterative neutral-axis equilibrium, tangent-stiffness degradation, and compression-side local shell-buckling assessment in a curvature-controlled incremental solution routine. This framework captures progressive stress redistribution, neutral-axis migration, degradation of flexural rigidity and transition from material-controlled compression failure to local shell instability. Validation was performed against experimental results for five filament-wound glass/vinylester tube configurations with nominal ±55° winding and diameter-to-thickness ratios, D/t, ranging approximately from 20 to 75. The predicted load–deflection and moment–curvature responses were in good agreement with the experimental measurements with mean errors of about 1.6% for peak load, 1.8% for ultimate bending moment and 2.4% for peak curvature. The model also reproduces the experimentally observed governing failure mechanisms over the investigated configurations. The convergence study with sectional discretization showed that 200 integration layers provide a good compromise between numerical accuracy and computational efficiency, with less than 1% variation compared to the refined 500-layer reference solution. The proposed reduced-order formulation has low computational cost in the present implementation and provides a direct physical interpretation of the evolving sectional response. Because a directly comparable finite-element runtime was not reported for the benchmark model, no quantitative FE speed-up factor is claimed. Thus, the proposed framework provides an efficient analytical tool for the nonlinear flexural evaluation of hollow filament-wound GFRP tubes in the validated geometric, loading and laminate domain. Full article

Headspace–gas chromatography–ion mobility spectrometry (HS-GC-IMS) combined with chemometrics was employed to track volatile aroma compounds during the nine-steaming and nine-drying process. A total of 84 volatile signals (including monomers, dimers, and polymers) were tentatively identified, of which 73 volatile compounds were semi-quantified. Principal component analysis (PCA) revealed a mixed clustering pattern across cycles, indicating that unsupervised methods alone could not adequately resolve the volatile changes. A partial least squares discriminant analysis (PLS-DA) model supported clear chemical discrimination among the three hypothesized stages—early (cycles 1–3), middle (4–6), and late (7–9). Based on VIP > 1 and ANOVA (q < 0.05), 29 key differential compounds were screened and categorized into three dynamic groups (decreasing, transient, and accumulating), revealing three proposed transformation windows: green-grassy odor dissipation (cycles 1–3), roasted/malty aroma generation (cycles 4–6), and aroma stabilization via end-product accumulation (cycles 7–9). Relative odor activity value (ROAV) analysis revealed a decoupling between abundance and sensory impact: high-abundance Maillard products like maltol showed negligible ROAV (<0.0003), whereas esters and aldehydes dominated the ROAV profiles, suggesting their potential as important contributors to the fruity, sweet, and malty notes. The maltol/α-cedrol ratio (M/C) increased by an order of magnitude after the seventh steaming, and color parameters E*ab correlated negatively with ester accumulation. This study provides chemical insights and quantitative indicators for aroma quality control and process determination in black ginseng production. Full article

Hydrophilic polymer films containing environment-sensitive chromophores are useful model systems for examining optical responses in polar matrices. In this study, chitosan/poly(vinyl alcohol) (CS–PVA) films containing low nominal loadings of 3-hydroxyflavone (3HF; 0.05–0.20 wt.%) were prepared by solution casting and characterized in terms of macroscopic appearance, thickness, ultraviolet–visible (UV–Vis) response before and after ultraviolet-A (UV-A) exposure, Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), and water-related behavior. All formulations produced continuous and macroscopically translucent films without visible precipitation or phase separation. Film thickness varied substantially among formulations (0.100–0.168 mm), requiring cautious interpretation of raw transmittance data. Before UV-A exposure, the thickness-normalized apparent attenuation coefficient at 365 nm (α_app,365) ranged from 23.84 to 121.74 cm⁻¹ and followed a non-monotonic order: CS–PVA–3HF-0.05 > CS–PVA–3HF-0.20 > CS–PVA–3HF-0.10 > CS–PVA. UV-A exposure for 120 min produced formulation-dependent changes in optical response, with no common concentration-dependent trend. FTIR-ATR spectra showed relatively small variations in the O–H/N–H, carbonyl/amide, and C–O regions; because several band displacements were comparable to the instrumental resolution, these changes were interpreted as variations in the local vibrational environment rather than direct evidence of hydrogen-bond-network restructuring. Water-contact measurements revealed very high apparent water uptake together with post-immersion dry-mass losses above 94%, demonstrating limited aqueous stability. Density functional theory (DFT) calculations combined with Multiwfn wavefunction analysis on isolated 3HF, a three-unit poly(vinyl alcohol) oligomer (PVA3), and a two-unit chitosan oligomer (CS2) described their intrinsic electronic features but did not establish intermolecular complex formation or directly explain the experimental responses. Overall, the results provide a descriptive characterization of the optical and water-related behavior of 3HF-containing CS–PVA films while emphasizing the influence of film geometry and the limitations associated with nominal, rather than analytically verified, chromophore loading and isolated-component computational models. Full article

The co-occurrence of microplastics and antibiotics in aquatic environments has raised increasing concern because their interactions remain poorly understood. This study investigated the interactions between two co-existing aquatic pollutants, antibiotics and microplastics, by evaluating the adsorption of nine commonly detected antibiotics onto PET, PP, and HDPE microplastics. The microplastics were considered environmentally contaminants rather than adsorbents intended for water treatment. Adsorption kinetics, equilibrium isotherms, and multi-component competitive models were employed, while the effects of the microplastic size, dosage, and water matrix composition were also studied. The adsorption kinetics for most antibiotics were best described by the pseudo-second order model (R² > 0.90), with the modelling suggesting contributions from film diffusion. The Freundlich and multi-component Sheindorf–Rebuhn–Sheintuch (SRS) models represented the equilibrium adsorption, indicating heterogeneous and competitive adsorption behaviour. PET exhibited the highest adsorption capacity, reaching 0.80 mg/g for doxycycline and 0.75 mg/g for oxytetracycline at 2000 mg/L microplastic. The competitive adsorption suggested that aromatic and moderately hydrophobic antibiotics showed greater adsorption, while highly polar antibiotics exhibited weaker adsorption and greater displacement. Potential interactions included electrostatic interactions, hydrogen bonding, and π–π interactions. These findings provide insights into antibiotic–microplastic interactions and emphasise the roles of the polymer type, molecular structure, and environmental conditions in influencing antibiotic fate and transport in aquatic environments. Full article

Organic electrochemical transistors (OECTs) utilize ion injections to regulate the overall conductivity of the organic semiconductor channel, achieving high transconductance (g_m) by coupling ionic and electronic charge carriers within the whole channel’s volume. However, the slow ion migration rate through the hydrophobic semiconducting polymer layer restricts the response rate of the device for widespread applications in biomedical sensing. This work introduced poly(ethylene glycol) (PEG) bisazide photo-crosslinking agent into the p-type semiconducting polymers as a hydrophilic active channel in accumulated-mode OECTs. Upon incorporation of PEG segments into conjugated polymers via photolithography, the resulting OECTs exhibit a significant enhancement in both µC* product and doping/de-doping dynamics by at least one order of magnitude. The photo-patterning of an ion-conducting semiconductor channel with a minimum line gap of 5 µm enables the fabrication of a depletion-mode inverter. This study presents a straightforward patterning process that enhances the hydrophilicity of various hydrophobic conjugated polymers while eliminating the need for complex synthesis procedures typically required for introducing ethylene glycol side chains on conjugated polymers. Full article

This study addresses the inherently low damping and vibration susceptibility of carbon fiber reinforced polymer (CFRP) laminated cantilever plates by developing a comprehensive dynamic modeling and active vibration control framework. An electromechanical coupling model incorporating macro-fiber composite (MFC) actuators and sensors is established using the first-order shear deformation theory (FSDT) and the assumed mode method, with virtual springs introduced to account for non-ideal clamped boundary conditions. A reduced-order state-space model is then derived through model reduction, and a linear quadratic Gaussian (LQG) controller is designed for optimal state estimation and feedback control. The theoretical model is systematically validated via convergence analysis, ANSYS finite element simulations, and LMS impact hammer testing. The results demonstrate that, with the relative errors of the first four natural frequencies controlled within 2%, the theoretical mode shapes are highly consistent with those obtained from ANSYS simulations. An active vibration control experimental platform is established, and the effectiveness of the control strategy is verified under dual-spectrum harmonic and impact excitations. The results show that the designed LQG controller can effectively suppress multi-modal vibrations, substantially attenuating the response amplitudes of dominant modes and significantly accelerating the transient vibration convergence. This study addresses the challenge of precisely characterizing actual non-ideal clamped boundary conditions. Through model order reduction and closed-loop LQG control experiments, it provides a comprehensive set of theoretical methodologies, numerical solution strategies, and engineering-oriented experimental schemes for the electromechanical coupling dynamic modeling and optimal vibration suppression of CFRP thin-walled composite structures. Full article