Abstract Multilayer plastic packaging is difficult to recycle because of its complex composition. Asphalt mixtures tolerate heterogeneous inputs, offering a practical valorization route. This study evaluates polypropylene-based multilayer plastic waste as a bitumen modifier for polymer modified bitumen (PMB). Mixtures containing 0, 3, 4, and 5 wt% plastic were assessed by the Marshall method. Plastic content significantly affected all seven Marshall parameters (two-way ANOVA, p < 0.001), most strongly Marshall Quotient ( η 2 = 0.76) and flow ( η 2 = 0.54). Tukey HSD contrasts showed the 4 and 5 wt% mixtures differed from the unmodified control while 3 wt% did not, placing the effective threshold between 3 and 4 wt%. Flow and volumetric properties (VMA, VIM, VFB) remained within Bina Marga 2018 limits throughout. Optimum asphalt content decreased stepwise from 5.93 wt% (unmodified) to 5.90, 5.83, and 5.70 wt% at 3, 4, and 5 wt% PMB – a 0.23 wt% reduction at equivalent specification compliance. The 5 wt% mixture combined full compliance with the highest stability (1,619 ± 67 kg) and lowest binder demand. Polypropylene-based multilayer waste is, therefore, viable as an asphalt modifier at mix-design level; durability and binder-level characterization remain necessary before field application.
Abstract Carbon fiber–reinforced composites (CFRP) are widely used in the aerospace industry due to their excellent properties. The quality of drilling in CFRP components has a significant impact on their structural integrity and in-service performance. Tool wear is a key factor determining drilling quality. To achieve data-driven process control, this study developed an integrated signal acquisition platform capable of simultaneously capturing acoustic emission (AE) and axial force signals during the drilling of CFRP. Under controlled and repeatable drilling conditions, acoustic emission and axial force signals were systematically recorded at each stage. A five-layer decomposition thresholding method based on the db4 wavelet was applied to the acoustic emission signals. This method effectively suppresses broadband noise while preserving the transient impact characteristics associated with the progressive degradation of the cutting edge. By analyzing acoustic emission signals and axial force in the time and frequency domains, among other methods, characteristic parameters highly correlated with the tool’s wear state were identified based on the Passion correlation coefficient. Finally, a classification method based on a convolutional neural network (CNN) under batch processing conditions was proposed to enable effective identification of tool wear under various operating conditions. This lightweight convolutional neural network achieved 94.44 % identification accuracy for tool wear, demonstrating strong potential for engineering applications.
Abstract Solar-driven simultaneous clean water production and organic pollutant photodegradation represent an effective strategy for sustainable treatment of organic wastewater. Here, we design a hybrid hydrogel composed of natural down fiber (DF) and Cu co-doped TiO 2 (DF–Cu@TiO 2 ) combined with DF-derived carbon (DFC) within a chitosan–polyvinyl alcohol matrix. The resulting DF–Cu@TiO 2 /DFC hybrid hydrogel achieves exceptional light absorption, sufficient water supply, and visible light-driven catalytic activity. Consequently, under one-sun illumination, the hydrogel demonstrated an evaporation rate of 1.87 kg m −2 h −1 and achieved a concurrent methyl orange (MO) degradation efficiency of 93.50 % within 5 h. Furthermore, the hydrogel exhibited self-floating capability, maintaining buoyancy continuously for over 7 days. Actual outdoor experiments yielded an evaporation rate of 1.21 kg m −2 h −1 at 12:00 p.m. and a simultaneous MO degradation efficiency of 95.71 % over a 10-h operational period (8:00 a.m.–6:00 p.m.). These findings provide valuable insights for designing multifunctional, self-floating evaporators for advanced wastewater treatment applications, particularly for wastewater containing harmful organic contaminants.
Abstract Overactive bladder (OAB) represents a prevalent and clinically significant urological disorder with substantial global impact. Conventional therapeutic approaches, including oral administration of antimuscarinic agents and β3-adrenoceptor agonists, often exhibit limited efficacy and are associated with undesirable systemic side effects, particularly gastrointestinal disturbances. To address these limitations, controlled drug delivery systems have emerged as a promising strategy to enhance therapeutic outcomes. Among these, transdermal patch (TP) technologies offer a noninvasive route for the sustained and targeted administration of pharmacologically active compounds. TP systems incorporating oxybutynin (OXY) and mirabegron (MRB) have been successfully formulated to enhance sustained drug delivery. The APIs were encapsulated within electrospun nanofibers and subsequently embedded into the patch matrix, enabling controlled and extended-release profiles. Comprehensive physicochemical characterization – including morphological, thermal, and mechanical analyses – was conducted to evaluate the structural integrity and functional performance of the composite system. In vitro release studies revealed that the nanofiber-enhanced TP extended the release of OXY by approximately fourfold compared to the reference commercial product, Kentera ® . A parallel formulation containing MRB was developed, leveraging its higher receptor affinity and pharmacodynamic potency to achieve therapeutic efficacy at significantly lower concentrations than OXY. Incorporation of nanofibers similarly resulted in a fourfold extension of MRB release time.
Abstract This study developed a chitosan-co-acrylamide hydrogel for controlled, pH-responsive delivery of venlafaxine hydrochloride. Hydrogels were synthesized via free-radical polymerization of chitosan and acrylamide, cross-linked with N,N′-methylenebisacrylamide (MBA), and initiated with ammonium persulfate (APS) and sodium metabisulfite (SMS). Three formulations with varying chitosan content (1.0, 0.2, and 0.1 g) were prepared and characterized by FTIR, SEM, TGA, DSC, and XRD to confirm structural integrity and thermal stability. Swelling was pH-dependent, with maximum uptake at pH 7.4 and minimum at pH 1.2. Drug release followed the same trend, with slower release at pH 1.2 and faster release at pH 7.4, attributed to greater hydration and expansion of the polymer network at higher pH; complete release occurred within 36–42 h, following zero-order kinetics ( R 2 ≈ 0.9998). Drug loading, performed by immersing dried hydrogel discs in 50 mL of venlafaxine hydrochloride solution (1 mg/mL) for 24 h at 37 °C, yielded encapsulation efficiencies of 92.00–99.23 %. Batch B (0.2 g chitosan) showed the highest encapsulation efficiency (99.23 %) and the most favorable balance of swelling, drug loading, and sustained release, identifying it as the optimum formulation for oral venlafaxine delivery.
