Search Results (784)

Wave-powered desalination systems integrate reverse osmosis (RO) with renewable ocean energy, providing a sustainable and environmentally responsible approach to freshwater production. This study aims to investigate wave-powered RO desalination using supervised and deep machine learning (ML) models to predict the effects of variable feed flow on permeate recovery and salt rejection under dynamic hydrodynamic conditions. Multiple ML models, including Gaussian process regression (GPR), support vector machines (SVMs), multi-layer perceptron (MLP), linear regression (LR), and decision trees (DTs) were systematically assessed for the prediction of permeate recovery and salt rejection (%) using three distinct input configurations: limited physicochemical features (M1), flow- and salinity-related parameters (M2), and a comprehensive variable set incorporating temperature (M3). GPR achieved near-perfect predictive accuracy R² values (~1.00) with minimal errors for permeate recovery and salt rejection, attributed to its flexible kernel and probabilistic design. MLP and SVM also performed well, though they showed greater sensitivity to feature complexity. In contrast, DT models exhibited limited generalization and higher error rates, particularly when key features were excluded. Sensitivity analyses revealed that feed pressure (FP) and brine salinity (BS) were dominant positive influencers of permeate recovery and salt rejection. In contrast, brine flow (BF) and permeate salinity (PS) had negative impacts. Full article

This study reports the development of electrospun poly(methyl methacrylate) (PMMA) fiber mats incorporating ibuprofen (IBU)-intercalated layered double hydroxides (LDH) for enhanced transdermal drug delivery systems (TDDS). IBU, in its anionic form, was successfully intercalated into LDH, which possesses anion exchange capabilities, and subsequently embedded into PMMA fibers via electrospinning. In vitro drug release experiments demonstrated that UPMMA–LDH–IBU fibers exhibited significantly higher IBU release than PMMA–IBU controls. This enhancement was attributed to the improved hydrophilicity and water absorption imparted by the LDH, as confirmed by contact angle and water uptake measurements. Furthermore, artificial skin permeation tests revealed that the UPMMA–LDH–IBU fibers maintained comparable release rates to those observed during buffer immersion, indicating that the rate-limiting step was the diffusion of IBU within the fiber matrix rather than the interface with the skin or buffer. These findings highlight the critical role of LDH in modulating drug release behavior and suggest that UPMMA–LDH–IBU electrospun fiber mats offer a promising and efficient platform for advanced TDDS applications. Full article

Vacuum Membrane Distillation (VMD) is a separation process applied to liquid solutions; however, there are phenomenological and operational differences depending on whether the component to be separated is the solute or the solvent. The objective of this article is to develop a mathematical and phenomenological model of the VMD process applied to the separation of volatile organic compound (VOCs) from aqueous solutions and the desalination of saline aqueous solutions. This approach enabled the evaluation of the influence of variables and operating conditions on both separation efficiency and system productivity. Under the analyzed conditions, increasing the temperature, flow rate, and vacuum pressure led to approximate increases in permeate flux of 400%, 10%, and 50%, respectively. In the case of concentration increase, the permeate flux increases linearly for VOC separation and decreases asymptotically for saline solution desalination. Therefore, adjusting the feed temperature is recommended to achieve significant changes in permeate flux. Full article

This study proposes a novel approach for preparing a laminated carbides and nitrides (MXene) membrane with loose nanochannels by intercalating cellulose nanocrystal (CNC) and cross-linking with glutaraldehyde. The interlayer spacing of the MXene membrane can be expanded by one-dimensional CNC, while cross-linking with glutaraldehyde enhances the stability of the membrane. The optimized membrane displays a high water permeate flux of 96.8 L m⁻² h⁻¹ (2.1 times higher than MXene membrane) and good selectivity (methyl blue rejection rate: ~99.6%; NaCl rejection rate: <5.0%). This strategy provides a universal way to prepare high-performance two-dimensional membranes. Full article

SiCp/Al composites (Silicon Carbide Particle-Reinforced Aluminum Matrix Composites), due to their light weight, high strength, and superior wear resistance, are extensively utilized in aerospace and other sectors; nonetheless, they are susceptible to tool wear and surface imperfections during machining, which negatively impact overall machining performance. Supercritical carbon dioxide minimal quantity lubrication (SCCO₂-MQL) is an environmentally friendly and efficient lubrication method that significantly improves interfacial lubricity and thermal stability. Nonetheless, current lubrication models are predominantly constrained to gas–liquid two-phase scenarios, hindering the characterization of the three-phase lubrication mechanism influenced by the combined impacts of SCCO₂ phase transition and ultrasonic vibration. This study formulates a lubricant film thickness model that incorporates droplet atomization, capillary permeation, shear spreading, and three-phase modulation while introducing a pseudophase enhancement factor β_ps(p,T) to characterize the phase fluctuation effect of CO₂ in the critical region. Simulation analysis indicates that, with an ultrasonic vibration factor Af = 1200 μm·kHz, a lubricant flow rate Q_f = 16 mL/h, and a pressure gradient Δp_tot = 6.0 × 10⁵ Pa/m, the lubricant film thickness attains its optimal value, with Δp_tot having the most pronounced effect on the film thickness (normalized sensitivity S = 0.488). The model results align with the experimental trends, validating its accuracy and further elucidating the nonlinear regulation of the film-forming process by various parameters within the three-phase synergistic lubrication mechanism. This research offers theoretical backing for the enhancement of performance and the expansion of modeling in SCCO₂-MQL lubrication systems. Full article

Background/Objectives: The principal function of pharmaceutical blister packaging is to provide protection for the drug product. Moisture is regarded as a critical factor in the physical and chemical aging of drug products. The present work proposes a modeling framework to predict the performance of tablet blister materials based on the moisture uptake profile of the drug product as well as degradation characteristics of the drug substance, while the consumption of water due to degradation is included. Methods: The model incorporates three kinetic superimposed processes that define moisture uptake and drug stability. The processes of permeation, sorption and degradation are each described with a rate constant. Based on a mass balance, these rate processes are interconnected and the relative humidity in the blister cavity is predicted. Results: In a case study, the model was applied to demonstrate the feasibility of predicting the stability of blistered tablets. By establishing a correlation between the moisture uptake of the tablet and the drug stability demonstrated in the model, it was feasible to predict the drug content over shelf life. Conclusions: Modeling of the drug stability of blister-packed products enables a rational packaging which offers novel possibilities for reducing material in order to avoid overpackaging of pharmaceutical products. As some of the commonly used barrier materials are considered to not be sustainable, this model can be used to consider a rationally justified reduction or even abandonment of the barrier materials. Full article

Objective: The objective of this study was to develop a Physiologically Based Biopharmaceutics Modeling (PBBM) framework that can predict PK profiles in humans based on data generated from the BE Checker. Methods: Metoprolol and dipyridamole were selected as model drugs. A mathematical model was developed to describe drug dissolution, membrane permeation, and dynamic changes in pH and fluid volume within the BE Checker system. Using data generated under various experimental conditions, dissolution rate constants were estimated. For dipyridamole, the precipitation rate constant was also estimated, assuming simultaneous dissolution and precipitation processes. The estimated parameters were subsequently incorporated into the human PBBM to simulate PK profiles. Finally, the predictive accuracy of PK parameters such as Cmax and AUC was assessed. Results: For metoprolol, the PK profiles using the paddle revolution rates of 100 and 200 rpm closely matched the observed human data, particularly for Cmax and AUC, a key indicator of BE. In the case of dipyridamole, accurate predictions of the mean human PK profile were achieved when using BE Checker data obtained under high paddle speed (200 rpm) and longer pre-FaSSIF infusion times (20–30 min). Conversely, simulations based on lower paddle speed (50 rpm) and shorter pre-FaSSIF infusion time (10 min) underestimated plasma concentrations in humans. Conclusions: These findings suggest that the combination of BE Checker data acquired under high agitation conditions and the in silico mathematical model developed in this study enables accurate prediction of average human PK profiles. Full article

Substituting cement with mineral additives like fly ash is increasingly essential for sustainable production. While replacement rates largely depend on fresh-state properties, the interaction between fly ash and polycarboxylate ether (PCE) molecular structures remains underexplored. In this regard, this study investigates the effect of PCE molecular structures and weight on the rheology, setting, and strength of cementitious systems containing up to 45% fly ash additions. Seven distinct PCE possessing different molecular weights (27,000–78,000 g/mol) as well as backbone and side chain lengths are synthesized. The interaction between PCE and solid particles was explored through total organic carbon, dynamic light scattering, and gel permeation chromatography. Test results showed that the adsorption rates of the cement and fly ash particles within the cementitious composites improved by up to 90% with fly ash replacement and upon using PCE with a medium molecular weight of 56,000 g/mol, backbone length of 21 k, and short side chain length of 1000 g/mol. This has resulted in a 75% reduction in the material’s apparent viscosity, delayed setting times of up to 38%, and improved early- and late-age compressive strengths of up to 123%. Such data can interest cement and admixture producers in proposing suitable PCEs for superior fly ash concrete performance. Full article

Developing efficient bio-based membranes is key to sustainable wastewater treatment, especially when they can be applied across multiple separation processes for components of varying molecular weights. This study reports the development and characterization of bio-based mixed matrix membranes from carboxymethyl cellulose (CMC) modified with synthesized carboxylated graphene oxide (GOCOOH), aimed at improving performance in both pervaporation and nanofiltration for water treatment. Membrane design was optimized by adjusting the GOCOOH content, applying chemical cross-linking (by immersing in glutaraldehyde with H₂SO₄), and developing highly effective supported membranes (by the deposition of a thin selective CMC-based layer onto a porous substrate). Comprehensive characterization was performed using spectroscopic, microscopic, and thermogravimetric analyses and contact angle measurements. The optimized cross-linked supported CMC/GOCOOH (5%) membrane demonstrated significantly improved transport properties: a 2.5-fold increased permeation flux and over 99.9 wt.% water in permeate in pervaporation dehydration of isopropanol, and high rejection rates—above 98.5% for anionic dyes and over 99.8% for heavy metal ions in nanofiltration. These findings demonstrate that CMC/GOCOOH membranes are promising, sustainable materials suitable for multiple separation processes involving components of varying molecular weights, contributing to more efficient and eco-friendly wastewater treatment solutions. Full article

Membrane separation is an effective means of separating 1,3-propanediol (1,3-PD) from fermentation broth. However, systematic studies on membrane fouling behavior during this process are still limited. Therefore, this study systematically analyzed the membrane fouling behavior during the clarification of 1,3-PD fermentation broth using ultrafiltration/microfiltration and explored the effects of different membrane materials, pore sizes, and shear rates on permeation efficiency, target product recovery rate, and impurity removal rate. The results showed that the filtration of 1,3-PD fermentation broth was mainly dominated by cake formation, and the main foulant was identified as proteinaceous substances. Otherwise, increasing the shear rate adjacent to the membrane did not alter the membrane pore fouling mechanism, but it can disrupt the reversible fouling layer and reduce the growth rate of the fouling layer. Meanwhile, the results also indicated that the PES 100 kDa membrane exhibited the best overall performance with high recovery rate of 1,3-PD and excellent removal effects on impurities, significantly reducing the subsequent purification burden. This study provides more theoretical basis and data support for the optimization of membrane separation processes in 1,3-PD fermentation broth clarification. Full article

This study reports the first synthesis of a new type of ether-polyalphaolefin (DVE-PAO) base oil via free radical bulk copolymerization using triethylene glycol divinyl ether (DVE-3) and α-olefin in drip-feed mode. The characteristic structure of DVE-PAO was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance Spectroscopy (NMR). The relative molecular weight and molecular weight distribution of DVE-PAO were determined using gel permeation chromatography (GPC). Structurally, it is a new type of base oil that integrates both polyalkylene glycol (PAG) and polyalphaolefin (PAO) structural units. The research shows that the viscosity of DVE-PAO base oil, the conversion rate of α-olefin, and the pour point of the copolymer increase with rising copolymerization temperature. Additionally, results from the rotating oxygen bomb test indicate that the oxidation stability of DVE-PAO also improves with increasing viscosity. Based on the principles of free radical copolymerization, this study provides a preliminary elucidation of the copolymerization patterns between the aforementioned double-ended vinyl ethers and α-olefins. Furthermore, the DVE-PAO base oil exhibits excellent miscibility with both mineral oils and polyalphaolefin (PAO) base oils. As a result, this ether-based polyalphaolefin is expected to find broad applications in the field of lubricants. Full article

Vacuum membrane-based air dehumidification (MAD) is potentially more efficient than refrigeration cycles. Air permeance through a membrane is inevitable, especially when there is a large pressure difference between the supply and permeate sides. Given the high specific gas volume under vacuum conditions, removing the permeating air from the dehumidifier is crucial for the stable operation of the vacuum compressor. Energy-efficient air removal techniques are still lacking, thereby hindering the development of MAD technology. This paper proposes a novel MAD approach using a vacuum mixing condenser. The cooling water directly condenses moisture from the vacuum compressor without any heat exchanger. The permeating air and water mixture in the condenser then experiences a quasi-isothermal pressurization process through a multiphase pump, enabling continuous dehumidification and air removal with low power consumption. The fundamentals of the proposed approach are illustrated, and mathematical models are built. Influences of air permeance rate, cooling water flow rate, condenser pressure, membrane area, and gravitational work are investigated. The results show that a COP of 8~12 is achievable to dehumidify air to 50%RH, 25 °C. The vacuum compressor consumes about 80% of the power. A low air permeance rate, low condenser pressure, large membrane area, and high gravitational work positively impact the COP, while the cooling water flow rate has a more complex effect. The proposed dehumidifier can use less selective membranes for higher permeability and cost-effectiveness. Full article

Background/Objectives: The pulmonary administration of levodopa enables a rapid absorption and onset of action, making it a suitable administration route for managing OFF episodes in Parkinson’s disease. Currently, one dry powder product for inhalation (Inbrija) is available on the market, while another (Levodopa Cyclops) is in development. These two products differ substantially in terms of inhaler design, their use and resistance, and their powder formulations. This study aimed to investigate whether these differences translate into in vitro differences in aerosol characteristics and dissolution kinetics and whether any differences were also reflected in the in vivo performance. Methods: The in vitro aerosol characteristics were determined via Next Generation Impactor experiments, and the dissolution kinetics were determined with a modified paddle apparatus. A randomized crossover comparative bioavailability study with fasted healthy volunteers was conducted with Inbrija 84 mg and Levodopa Cyclops 45 mg, 90 mg, and 135 mg. Results: The results showed similar aerosol characteristics, but Levodopa Cyclops showed substantially faster dissolution behavior than Inbrija. Despite this in vitro difference, the pharmacokinetic profiles of Inbrija 84 mg and Levodopa Cyclops 90 mg were similar, with no differences in C_max, T_max, and AUC, showing bioequivalence between the two products. Conclusions: This suggests that the systemic absorption of levodopa via the lungs is not limited by dissolution but most likely by its permeation rate. This finding underscores the need to critically apply in vitro tests and critically interpret the results for predicting the in vivo performance of inhaled products. Full article

This study investigates the valorisation of sour orange (Citrus aurantium L.) flowers using supercritical antisolvent fractionation (SAF) with CO₂ as an antisolvent. SAF was applied to selectively recover bioactive compounds from ethanolic extracts, using supercritical CO₂ to induce precipitation. Response Surface Methodology (RSM) was employed to optimize operational conditions across a pressure range of 8.7–15 MPa and CO₂ flow rates of 0.6–1.8 kg/h, at a constant temperature of 40 °C. Pressure showed a statistically significant positive effect on precipitate yield, while higher CO₂ flow rates led to reduced recovery. High-performance liquid chromatography (HPLC) analysis identified naringin (33.7%), neohesperidin (21.6%), and synephrine (9.0%) as the main components of the enriched fractions. SAF enabled the selective concentration of these compounds, supporting its application as a green separation technique. As a complementary evaluation, preliminary in silico predictions of ADMET properties and skin permeability were performed. The results indicated favourable absorption, low predicted toxicity, and limited dermal permeation for the major flavonoids. These findings are consistent with available experimental and regulatory safety data. Overall, the study demonstrates the potential of SAF as an effective green technology for the selective extraction and enrichment of high-value bioactive compounds derived from Citrus aurantium flowers, with promising applications in cosmetic, nutraceutical, and pharmaceutical formulations. Full article

This study presents a facile approach to fabricate PBAT/PHBV films with superior mechanical and barrier properties by in situ forming ribbon-like lamellae, achieving a PHBV platelet-reinforced PBAT films. The fabrication involves melt blending of PBAT and PHBV, where styrene–methyl methacrylate–glycidyl methacrylate copolymer as a multifunctional reactive compatibilizer (RC) regulates PHBV domain size by forming a branched/cross-linked PBAT-B-PHBV structure. The introduction of a compatibilizer into the PBAT/PHBV system can reduce domain size and improve interfacial adhesion, thereby elevating PBAT’s storage modulus and complex viscosity for optimized blow-molding processability. During blow-molding, biaxial stretching with rapid cooling transforms PHBV sea–island structures into well-aligned ribbon-like lamellae. Notably, when PHBV content is ≤30 wt.%, lamellae form in the PBAT matrix, significantly enhancing both mechanical and barrier properties. The addition of RC reduces the lateral dimensions of PHBV lamellae while increasing PHBV number density. The introduction of 0.2 wt.% RC optimizes lamellar dimensions and density to maximize permeation pathway tortuosity. Ultimately, the lamellae in the PBAT matrix yield remarkable property enhancements: yield strength increased by >600%, elastic modulus by >200%, and water vapor/oxygen transmission rate reduced by ~81% and ~85%, respectively. Full article