Search Results (3,987)

We present a one-dimensional shear-force-driven droplet formation model with a flux-based error estimator. The model is derived using asymptotic expansion and a front-tracking method to simulate the droplet interface. The model is then discretized using the Galerkin finite element method in the mixed form. However, the solution gradients exhibit large jumps across element boundaries and can grow rapidly due to the highly convective pinch-off process. This leads to an erroneous droplet interface and incorrect curvature. Therefore, the mesh must be sufficiently refined to capture the interface accurately. The mixed form of the governing equation naturally provides smooth interface gradients that can be used to compute the error estimate. The computed error estimate is then used to drive the adaptive mesh refinement algorithm. The efficacy of the error estimator is illustrated by comparing the droplet profiles obtained with adaptive refinement to those obtained with regular refinement. The adaptive mesh refinement approach reduces the computational cost significantly without compromising accuracy. For an 85% glycerol droplet in co-flowing air, AMR reproduces pinch-off location, surface area, volume, and pinch-off time with only ≈1% accuracy loss compared to the highly refined reference while reducing wall-clock time from 638 s to 153 s (4.17× speedup) and reducing the maximum element count from 800 to 146 (81.75% reduction). Full article

Direct air capture (DAC) requires carbon capture interfaces that operate under highly dilute CO₂ conditions while minimizing thermal and chemical regeneration penalties. Carbonic anhydrase (CA) accelerates the reversible hydration of CO₂ to bicarbonate and is therefore a strong biocatalytic candidate for low-temperature CO₂ capture, but its implementation depends on candidate support materials that combine wet-state accessibility, chemical reactivity, mechanical processability and compatibility with membrane architectures. This study reports the preparation and screening of N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS)-reactive biopolymer composite membranes for future carbonic anhydrase (CA) immobilization. Chitosan particles were precipitated with citrate or tripolyphosphate under high-shear homogenization and compared after lyophilization or convective drying. Chitosan-, shellac-, agarose- and cellulose-acetate-based films plasticized with glycerol and/or polyethylene glycol 400 (PEG-400) were then evaluated by optical microscopy, dry-state penetrometric puncture testing, qualitative EDC/NHS-reactivity mapping and Fourier-transform infrared spectroscopy (FTIR). Freshly precipitated chitosan particles showed dendrite-like high-surface morphologies, while lyophilization preserved porous flocculated aggregates and convective drying produced denser collapsed structures. Neat chitosan showed the highest dry-state puncture force (2.230 ± 0.173 N), whereas chitosan/shellac (0.377 ± 0.044 N) and agarose/chitosan/PEG-400 (0.386 ± 0.038 N) provided the strongest reactive-composite compromise between dry-state puncture resistance and EDC/NHS compatibility. The EDC/NHS reactivity map identified chitosan- and shellac-containing films as the chemically most relevant supports because they provide amine and/or carboxyl functionality, whereas agarose and cellulose acetate alone were not directly suitable for zero-length amidation. FTIR spectra confirmed polymer-specific functional signatures and EDC/NHS-associated changes in carbonyl, amide and C-O/C-O-C regions, especially in shellac- and chitosan-containing composites. The results identify chitosan/shellac as the lead candidate membrane and agarose/chitosan/PEG-400 as a hydration-rich comparator for subsequent carbonic anhydrase immobilization studies. This work should be interpreted as a first-stage materials-screening study of candidate membranes for enzyme immobilization. Full article

Mg–La mixed metal oxides derived from layered double hydroxide (LDH) precursors were synthesized via coprecipitation and evaluated as heterogeneous catalysts for solventless glycerol etherification to short-chain polyglycerols. The influence of Mg/La molar ratio on the structural, textural, and catalytic properties of the catalysts was systematically investigated using XRD, BET, SEM-EDX, FTIR, TPD-CO₂, TPD-NH₃ and ICP-OES analyses. XRD confirmed the formation of La₂O₂CO₃ phases, while CO₂-TPD analysis revealed the presence of abundant medium-to-strong basic sites. Among the synthesized catalysts, Mg_0.25La_0.75O₂ exhibited the highest basic site concentration (6830 µmol g⁻¹) and superior catalytic performance due to the possible cooperative interaction between Mg- and La-derived sites. Under optimum reaction conditions of 220 °C, 8 h, and 2 wt% catalyst loading, the catalyst achieved 90% glycerol conversion with 70% diglycerol selectivity, 23% triglycerol selectivity, and 84% combined diglycerol and triglycerol yield. Reaction temperature, catalyst loading, and reaction duration significantly influenced oligomer distribution and catalyst performance. Reusability studies demonstrated acceptable catalyst stability for up to four cycles before gradual deactivation caused by oligomer deposition and metal leaching. The results highlight Mg–La mixed oxides as promising catalysts for sustainable solvent-free glycerol valorization, while demonstrating a scalable and environmentally benign strategy for maximizing lower-degree polyglycerol production within shorter reaction durations and reduced processing cost. Full article

Hydrocarbon biodegradation in cold environments is constrained not only by microbial catabolic capacity but also by interfacial access to poorly soluble substrates and by the way remediation materials interact with microbial envelope-related structures. This study presents an uncertainty-aware low-temperature computational screening workflow for prioritizing functionalized oxide surface-patch models that may favor hydrocarbon association while avoiding excessive perturbation of simplified microbial-interface proxies. Twelve finite oxide–ligand candidates derived from TiO₂, ZnO, and CeO₂ patches functionalized with bare, catechol, glycerol, or citric acid states were evaluated against three hydrocarbon probes, hexane, toluene, and naphthalene, and two microbial-interface proxies. The workflow combined GFN2-xTB geometry optimization and relative interaction-energy screening, clean GFN2-xTB/ALPB rescoring with rescue tracking, short xTB-MD perturbation analysis, ORCA refinement of selected candidates, sensitivity analysis of ranking parameters, and integrated evidence classification. The analysis supports interfacial selectivity, rather than maximum adsorption strength, as the central design principle. TiO₂–catechol and TiO₂–glycerol remain experimentally testable primary candidates because their original screening profile combines chemically interpretable hydrocarbon association with comparatively mild microbial-proxy interaction descriptors. ZnO–catechol and ZnO–glycerol emerged as sensitivity-competitive secondary candidates under several scoring assumptions. Completed short xTB-MD trajectories further showed that TiO₂–glycerol produced moderate perturbation against the peptide proxy, whereas TiO₂–glycerol against NAG and ZnO–catechol against the peptide proxy showed very high proxy displacement. Overall, the workflow provides a transparent prioritization framework for experimental validation. Full article

Microalgal lipids are promising sustainable feedstocks for high-value functional ingredients. However, the influence of cultivation-driven lipid composition on enzymatic conversion remains poorly understood. This study integrated cultivation strategy and enzymatic upgrading to tailor Neochloris oleoabundans lipids for mono- and diacylglycerol (MAG and DAG) production. Heterotrophic cultivation achieved a maximum dry biomass concentration of 2.78 ± 0.14 g L⁻¹, whereas autotrophic cultivation reached 0.39 ± 0.01 g L⁻¹, confirming the superior biomass productivity of heterotrophic metabolism. Lipid fractions obtained under both trophic conditions were characterized and subjected to glycerolysis catalyzed by Novozym 435 under a 5:1 glycerol-to-oil ratio for 16 h. Heterotrophic oils, characterized by triacylglycerol-rich and low-free fatty acid (FFA) profiles, achieved higher MAG + DAG conversion (45%), while autotrophic oils reached 43% conversion despite elevated FFAs and polar lipids. The presence of FFAs, pigments, and phospholipids in non-refined microalgal oils influenced catalytic behavior, reducing conversion efficiency and favoring competing esterification and hydrolysis pathways. These findings demonstrate that substrate purity, acylglycerol distribution, and cultivation-specific lipid architecture strongly affect lipase performance, highlighting oil refining and cultivation optimization as key strategies for improving sustainable MAG and DAG production. Full article

MAFLD progression is closely linked to a systemic failure of antioxidant defense systems. Se and Zn play crucial roles in maintaining redox balance in the liver. This study evaluated the effects of micronutrient-biofortified chickpea flours as functional ingredients for the prevention and management of MAFLD disturbances. Chickpea seeds were germinated with Na₂SeO₃, ZnSO₄, ZnSeO₃, or ZnSO₄ + Na₂SeO₃, processed into flours, and then subjected to gastrointestinal digestion to obtain biofortified-chickpea digests (BCD). SDS-PAGE and FTIR indicated treatment-dependent changes in the protein/peptide profile and in the structural organization of the digested matrix. Isoflavone content was higher in ZnSO₄-BCDs. The oleic acid-induced HepG2 cell model was used to emulate MAFLD conditions. Under preventive conditions, except for ZnSeO₃-BCD, all treatments reduce triglyceride accumulation from 17.1 to 38.6%. Non-biofortified (GC) chickpea flour and ZnSeO₃-BCD had greater effects on lipolysis and glycerol release. Overall, Se-BCD affected redox regulation 1.2–1.3-fold, suggesting potential improvement in lipid utilization. GC and ZnSO₄ + Na₂SeO₃ BCDs decreased triglyceride accumulation (21.1 and 20.5%, respectively) when evaluated post lipid exposure. In both experimental conditions, BCDs significantly reduced IL-6 levels by 25.1 to 34.7%, demonstrating their immunomodulatory potential. Biofortified chickpea flours exhibit complementary and coordinated biological activities against the main metabolic disturbances associated with MAFLD. Zn/Se-biofortification of chickpea is a valuable strategy for addressing micronutrient deficiencies and for producing functional ingredients to prevent or ameliorate MAFLD-associated disturbances and improve liver health. Full article

Phosphogypsum (PG) was used as a calcium source for preparing calcium carbonate (CaCO₃) through NH₄Cl leaching followed by high-pressure carbonation. The effects of NH₄Cl concentration, liquid-to-solid mass ratio, temperature, and leaching time on Ca²⁺ extraction were investigated, and the effects of CO₂ pressure, carbonation time, and NH₃·H₂O dosage on Ca²⁺ conversion were evaluated. The optimal conditions were an NH₄Cl concentration of 1.5 mol/L, a liquid-to-solid mass ratio of 60:1, a leaching temperature of 25 °C, a leaching time of 60 min, a CO₂ pressure of 1 MPa, a carbonation time of 10 min, and 12 vol% NH₃·H₂O addition. Under these conditions, the Ca²⁺ leaching rate and conversion rate reached 81.25% and 97.36%, respectively. The product obtained without organic additives was mainly spherical vaterite with partial particle agglomeration. Based on the optimized process, aspartic acid, glutamic acid, ethanol, and glycerol were introduced to regulate CaCO₃ crystallization. Appropriate additive dosages further improved Ca²⁺ conversion, promoted calcite as the dominant polymorph, and produced well-dispersed spherical CaCO₃ particles. Among the tested additives, glutamic acid and glycerol showed the strongest effects on crystal morphology regulation. Full article

The study presents the results of research on the preparation of biopolyols based on organosolv lignin and their application in the synthesis of rigid polyurethane foams. The research was conducted in order to develop a sustainable alternative to the previously used ethylene carbonate in lignin oxyalkylation processes. The main objective was to replace the previously used ethylene carbonate with propylene carbonate in a stoichiometrically equivalent molar amount in order to reduce polyol viscosity and improve the performance properties of the resulting foams. The syntheses were carried out without the need for isolation and purification of intermediate products. Polyols analogous to those described previously were obtained and subsequently used for the preparation of rigid polyurethane foams employing polymeric diphenylmethane diisocyanate. The properties of the obtained foams were investigated and compared with those of foams prepared from ethylene carbonate-based polyols. The results demonstrated that the use of propylene carbonate leads to the formation of lower-viscosity polyols, facilitating homogenization of the reaction systems and enabling the production of foams with advantageous performance characteristics, generally superior to those of foams based on ethylene carbonate. The obtained materials constitute a promising alternative to conventional polyurethane foams derived from petrochemical raw materials. Full article

The development of highly crystalline tungsten oxide nanomaterials remains challenging for catalytic applications due to the difficulty in achieving high phase purity without sacrificing metal oxide loading. This work addresses this limitation through an innovative fast hydrothermal synthesis at 100${}^{\circ }\mathrm{C}$ for 4$\mathrm{h}$ without autoclaves or surfactants, using citric acid as a critical structural directing agent. Such methodology reduces the synthesis time by 50–80% compared to existing hydrothermal routes. Citric acid was identified as the critical parameter controlling the nanosheet thickness (20$\mathrm{n}$$\mathrm{m}$–35$\mathrm{n}$$\mathrm{m}$) and diameter (109$\mathrm{n}$$\mathrm{m}$–173$\mathrm{n}$$\mathrm{m}$), acting as a coordinating ligand. The resulting nanosheets were used to prepare Pt/WO3/Al2O3 catalysts with well-defined crystalline monoclinic WO3 structures at 9.5% wt. loading. Normally, this phase is inaccessible by standard impregnation at equivalent loading. NH3-TPD characterization confirmed that crystalline WO3 generates strong acid sites absent in the reference wet impregnation catalyst. Glycerol hydrogenolysis tests revealed that the presence of monoclinic WO3 reduces the average glycerol conversion rate by a factor of 3.8 and systematically shifts selectivity toward over-hydrogenolysis products (1-propanol and 2-propanol), despite identical WO3 loading and surface densities below the literature optimum of $2.2Watomsn{m}^{-2}$. These results demonstrate that the WO3 crystalline phase is a primary determinant of catalytic performance, without taking into account increased loading. Such demonstration will be useful for the rational design of selective glycerol hydrogenolysis catalysts. Full article

Sparkling wines are produced through a second fermentation of a base wine, whose composition strongly determines the final product quality. Yeast selection for primary fermentation is therefore crucial, as it influences both fermentation performance and sensory attributes. In this study, 156 yeasts were isolated from spontaneous fermentations of Vitis vinifera cv. Torrontés sanjuanino from Paraje de Hilario (1550 m.a.s.l., San Juan, Argentina), aiming to select autochthonous strains with oenological potential for sparkling base wine production. Isolates were phenotypically characterized and molecularly identified by sequencing the D1/D2 domain of the 26S rDNA. A total of 44 Saccharomyces cerevisiae and 60 non-conventional yeasts, mainly Hanseniaspora uvarum, were identified. Based on relevant oenological traits, two S. cerevisiae (M138M, F172M) and two H. uvarum (Mi14M, C135MJ) strains were selected. Laboratory and pilot-scale co-inoculation trials showed that the Mi14M/M138M (50:50) combination exhibited stable fermentation kinetics, low acetic acid production (0.44 g/L), high glycerol levels (7.1 g/L), and suitable pH (3.08) and ethanol content (11.2% v/v). Despite higher residual sugars than the control, no technological issues were observed. These findings support co-inoculation of autochthonous strains of S. cerevisiae and H. uvarum as a promising strategy to enhance wine quality and reinforce regional identity in sparkling base wines. Full article

The selective electrocatalytic conversion of glycerol into value-added products provides a sustainable and efficient strategy for addressing the surplus of biomass-derived waste generated from the biodiesel production. In this paper, a series of carbon-supported PtPdRhRu quaternary alloy nanocatalysts (PtPdRhRu/C) with different atomic ratios (Equi, Pt-rich, Pd-rich, Rh-rich and Ru-rich) were prepared via a one-pot polyol method. The effects of these atomic ratios on the catalytic performance and the selectivity of the glycerol conversion to high-value products were investigated. The as-prepared PtPdRhRu/C nanocatalysts all possess a single-phase face-centered cubic (fcc) structure. Specifically, their mass activities are 10.5, 9.4, 8.1, 1.9 and 6.4 times higher than that of commercial Pt/C (20 wt%) for the Pt-rich, equimolar, Pd-rich, Rh-rich, and Ru-rich catalysts, respectively. This enhancement is suggested to be associated with the unique electronic modulation and synergistic effects inherent in the multicomponent surface. The Pd-rich catalyst exhibits a selectivity of 72% for glyceraldehyde, while the Rh-rich catalyst shows 53% selectivity for oxalic acid. The C2/C3 product ratio for the Rh-rich catalyst reaches 1.13, compared to 0.82 for the Ru-rich catalyst, suggesting that the presence of Rh and Ru atoms promotes C-C bond cleavage. In contrast, the C2/C3 ratios of the Pt-rich and Pd-rich catalysts are relatively low; notably, the C2/C3 ratio of the Pd-rich catalyst is only 0.20. This implies that the inclusion of Pt and Pd elements in the quaternary alloy is more conductive to the retention of C3 frameworks. These findings highlight the PtPdRhRu platform as a versatile framework for tuning the geometric and electronic environment of catalysts, providing a strategic approach for the selective electro-conversion of complex polyols. Full article

Oil-in-water nanoemulsions (NE) can increase the water solubility of plant-derived bioactive molecules as drug candidates. Machine learning-guided NE design can prevent the expensive, time-consuming trial-and-error process. NE composition data was aggregated into a dataset; a predictive machine learning model identified improved self-nanoemulsifying system formulations (olive oil and combinations of Tween 20, Tween 80, glycerol, and soy lecithin). Predictive power was assessed by estimating successful self-nanoemulsification through transmittance and Dynamic Light Scattering. NEs were loaded with an organic extract containing anacardic acid. Encapsulation efficiency was measured by UHPLC. Antiproliferative activity was evaluated on human hepatic cancer (Hep G2) and normal-like human embryonic kidney (HEK-293) cell lines. The model showed an accuracy of 81%. The best-performing formulation, consisting of 10% olive oil, 60% Tween 20, and 30% glycerol, exhibited an average particle size of 162.8 ± 26 nm, a polydispersity index of 0.234 ± 0.03, and high encapsulation efficiency. While HEK-293 cells remained unaffected, naked NE exhibited a selective growth inhibitory effect on the Hep G2 cell line. Loaded NE increased the cytotoxic effect on Hep G2 (IC50: 5.9 ± 1.27 µM). Machine learning-guided NE formulation was a successful carrier for the plant extract and the molecule of interest, providing a proof of concept for how artificial intelligence can shorten the development pipeline for NE drug delivery systems. Full article

Cutin, a natural polyester, has attracted attention as a precursor for bio-based materials mimicking plant cuticles, particularly in food packaging. Most studies focus on polycondensation of hydrolyzed cutin fractions or combining cutin hydrolysates with other components; however, cutin precipitation, conditions affecting it, and cutin isolate film properties, without addition of other filmogenic material, remain insufficiently understood. Owing to the pH-dependent solubility of cutin, which progressively decreases as pH is lowered from strongly alkaline to acidic conditions, this study investigates the influence of pH on cutin dispersion formation and characteristics, and evaluates the impact of these dispersion properties on the formation and performance of self-assembled cutin isolate films, with a view to developing films with improved water-barrier and moisture-resistance properties. The influence of three plasticizers, glycerol, propylene glycol, and polyethylene glycol 400, at two concentrations was also evaluated. Results demonstrated that pH is the primary factor influencing cutin isolate dispersion characteristics and film performance, with decreasing pH promoting cutin precipitation and particle aggregation, thereby inducing changes in film structure. The strongest effects were observed for swelling, solubility, and tensile strength, followed by water vapor permeability, elongation at break, and thickness. Plasticizer type mainly affected moisture content and significantly influenced permeability and thickness, while concentration of plasticizer primarily impacted permeability. Interactions between pH and plasticizer significantly influenced most properties. Films prepared from cutin dispersions at pH 6.5 and pH 5 with polyethylene glycol (10%) showed the best balance of mechanical and barrier properties. Additionally, films prepared from the cutin solutions at pH 12 with glycerol (20%) exhibited good mechanical performance and high solubility, suitable for specific applications. Full article

As energy demand continues to increase, the environmental impact of conventional petroleum-based sources has become a growing concern. Biofuels offer a sustainable alternative, with crude glycerol from biodiesel production showing promise for methane production via anaerobic digestion. To optimize methane production, the application of ultrasound as a pretreatment method has been investigated. This study introduces the novel use of ultrasound pretreatment to enhance methane yield from crude glycerol and improve anaerobic digestion efficiency. This work explores the relationship between ultrasound-pretreated crude glycerol and methane production while also assessing the role of reactor operational parameters in determining the final generated volume. The main purpose of this study is to determine how ultrasound duration and process conditions affect biogas performance and to identify an optimal strategy for maximizing methane output from this biodiesel by-product. Chemical oxygen demand (COD) increased from 29.1 to 45.1 g L⁻¹ after 30 min of ultrasound, representing a 55% rise due to enhanced organic matter disintegration. Methane generation improved markedly with pretreatment duration, increasing from 520 mL (10 min) to 1440 mL (15 min) and reaching 13,185 mL after 30 min in the laboratory reactor. The methane volume obtained in 22 days from glycerol subjected to a 30 min ultrasound pretreatment using a 1% glycerol mixture reached an impressive 16,224 mL. Full article

Naringinase is an enzyme complex composed of α-L-rhamnosidase and β-D-glucosidase, capable of deglycosylating flavonoids such as hesperidin. α-L-rhamnosidase converts hesperidin into rhamnose and hesperetin 7-O-glucoside (Hes-7-G), while β-D-glucosidase further hydrolyses Hes-7-G to hesperetin. Selective inactivation of β-D-glucosidase enables accumulation of Hes-7-G, a compound with higher water solubility and bioavailability than hesperidin or hesperetin, making it valuable for food and biotechnological applications. This study aimed to identify conditions allowing selective inhibition of β-D-glucosidase while preserving α-L-rhamnosidase activity for efficient Hes-7-G production. The effects of pH, temperature, and incubation time were investigated, together with the influence of polyols and sugars, including inositol, sucrose, glycerol, xylose, erythritol, xylitol, and sorbitol, on α-L-rhamnosidase thermostability. Among the tested additives, erythritol significantly improved α-L-rhamnosidase thermostability. The highest selectivity was achieved by incubating the enzyme in 1.4 M erythritol at 70 °C for 10 min, resulting in ~5% residual β-D-glucosidase activity and 50% α-L-rhamnosidase activity. Under these conditions, α-L-rhamnosidase activity exceeded β-D-glucosidase activity by more than 60-fold. Selective thermal inactivation of β-D-glucosidase in the presence of erythritol provides an effective strategy for producing Hes-7-G from hesperidin and may enhance flavonoid bioavailability for industrial applications. Full article