Search Results (1,227)

The production of high-purity hydrogen from chemical hydrogen storage materials such as sodium borohydride (NaBH₄) has been identified as a particularly promising candidate due to its high hydrogen storage capacity and environmentally benign hydrolysis products. The incorporation of tungsten (W), thereby developing W-promoted NiMo catalytic systems, results in the enhance activity toward NaBH₄ hydrolysis, thereby developing ternary NiMoW catalytic systems. The synthesis of NiMoW-coated copper catalysts (NiMoW/Cu) containing 3–11 wt.% of W was accomplished using a cost-effective and efficient electroless deposition method from citrate-based plating baths containing Ni²⁺, Mo⁶⁺, and W⁶⁺ ions. Morpholine borane was utilized as the reducing agent in this process. The catalytic activity of the prepared coatings toward alkaline NaBH₄ hydrolysis increased as the tungsten content decreased within the investigated range of 3–11 wt.%. The highest hydrogen generation rate, reaching 9.87 L min⁻¹ gcat⁻¹, was achieved using the NiMoW/Cu catalyst containing 3 wt.% of W at 343 K. The corresponding apparent activation energy was calculated to be 52 kJ mol⁻¹. In addition, the catalyst demonstrated notable 89.1% stability, maintaining a high degree of catalytic activity after undergoing five successive hydrolysis cycles. The enhanced catalytic performance was attributed to synergistic interactions between Ni, Mo, and W and to the favorable surface morphology of the multicomponent coating, which promoted the hydrogen generation reaction. Full article

Sodium butyrate (NaBu), a short-chain fatty acid and histone deacetylase inhibitor, has been reported to influence protein acetylation and cellular function; however, its effects on boar spermatozoa remain poorly understood. This study evaluated the effects of NaBu on sperm function and global protein acetylation in fresh after 24 h storage and frozen–thawed boar spermatozoa. Semen samples collected from boars (n = 4), with three ejaculates per boar, were supplemented with 0, 0.5, 0.75, or 1 mM NaBu, stored for 24 h at 17 °C, and subsequently cryopreserved. Sperm motility, mitochondrial membrane potential, membrane integrity, apoptosis-like changes, and chromatin status were assessed using CASA, flow cytometry, and fluorescence microscopy, whereas global protein acetylation was assessed by Western blotting. In fresh semen after 24 h storage, NaBu did not significantly affect the evaluated sperm functional parameters, whereas frozen–thawed spermatozoa showed significant changes in selected functional parameters, particularly total and progressive motility at 0.5 mM. Selected mitochondrial membrane potential parameters were also affected in frozen–thawed samples, while membrane integrity, apoptosis-like changes, and chromatin status remained largely unaffected. NaBu did not significantly alter global protein acetylation levels in either fresh after 24 h storage or frozen–thawed spermatozoa. Considerable inter-individual variability between boars was observed. These findings indicate that NaBu may affect selected in vitro functional properties of frozen–thawed boar spermatozoa; however, the observed functional changes were not associated with detectable statistically significant changes in global protein acetylation under the conditions tested. Further studies are needed to determine whether specific acetylated proteins, metabolic pathways, or stress-response mechanisms are involved. Full article

Emissivity is a parameter allowing the assessment of thermal/optical properties of active pharmaceutical ingredients (APIs). ε reflects radiative properties, changes with product aging, and correlates with surface characteristics. This study analyzed the thermal emissivity of commercial tablets—extended-release tablets with metformin hydrochloride (from two manufacturers: XR I and XR II), coated (Co) tablets with ibuprofen, and chewable (Ch) tablets with sodium aluminum dihydroxycarbonate—and compared unexpired vs. expired products. We used the ET 100 emissometer (Surface Optics Corporation, USA; IR range 1.5–21 µm) to measure directional–hemispherical reflectance (DHR) at 300 K, and on the basis of these values, directional thermal emissivity at 20° (DTE20) and 60° (DTE60) and hemispherical thermal emissivity (HTE) were calculated. Then, emissivity parameters were evaluated at 500 K, 800 K, and 1200 K. The DHR values at a 60° angle differed between unexpired and expired XR II tablets across all spectral bands and for XR I tablets, except in the 3.0–4.0 micron range. In turn, for DHR at 20°, high effect sizes were demonstrated between unexpired and expired Ch tablets for 1.5–2.0, 2.0–3.5, 4.0–5.0, and 5.0–10.5 microns. For the DHR at 60°, the high effect size between unexpired and expired Ch tablets was found at 1.5–2.0, 2.0–3.5, and 4.0–5.0 microns. At 300 K, XR I and XR II tablets showed comparable DTE20, DTE60, and HTE. The Ch tablets had higher DTE20 than XR I and XR II (0.968 vs. 0.954 and 0.958, respectively; p < 0.001) and Co tablets (0.968 vs. 0.930; p < 0.001). The Co tablets had the highest DTE60 mean values (0.941 vs. 0.926 for Ch, p < 0.001; 0.926 for XR I, p < 0.001; 0.932 for XR II, p = 0.001). The HTE value was the highest for Ch tablets (p < 0.001 vs. others). During thermal modeling of the emissivity parameters, all DTE20, DTE60, and HTE values decreased with temperature, reaching their lowest values at 1200 K. The largest relative decrease in HTE values (over 15%) between the standard measurement temperature of 300 K and the modeled temperature of 1200 K was found for Ch tablets. Tablets with different release profiles show distinct DTE20, DTE60, and HTE values, suggesting that emissivity may serve as a rapid, non-destructive screening tool that could support further pharmaceutical evaluation during storage. However, emissivity alone does not establish pharmaceutical quality, and the present findings should be interpreted as proof-of-concept rather than as validation of a stand-alone quality-control method. Full article

Sodium alginate was extracted from beach-cast Sargassum spp. collected along the coast of Puerto Progreso, Yucatán, Mexico, using two established pretreatment routes based on formaldehyde and ethanol. This study evaluates how extraction methodology controls alginate recovery, molecular structure, hydrogel rheology, macroscopic integrity, swelling behavior, and preliminary inorganic contaminant profiles. The ethanol-based route provided the highest extraction yield, reaching 19.87 ± 0.79% w/w for AE-5, whereas the formaldehyde route reached a maximum of 15.60 ± 0.62% w/w for AF-12; statistical analysis confirmed significant differences among extraction conditions (ANOVA, p < 0.05). Despite its lower yield, the formaldehyde route produced alginate with higher intrinsic viscosity (2.13 dL/g) and viscosity-average molecular weight (1.00 × 105 g/mol) than the ethanol-derived sample (1.33 dL/g and 0.62 × 105 g/mol), indicating better preservation of polymer chain length. ¹H NMR analysis showed that AE-5 had higher guluronic acid content (F_G = 0.60), lower M/G ratio (0.67), and higher G-block fraction (F_GG = 0.54), favoring Ca²⁺-mediated junction zone formation. Consequently, AE-5-derived hydrogels exhibited the highest storage modulus at 1 Hz (G′ = 23,650 Pa), compared with AF-12-derived hydrogels (13,160 Pa) and the commercial reference (14,480 Pa). However, visual inspection and swelling analysis showed that the higher small-amplitude stiffness of AE-5 did not translate into superior macroscopic integrity; these hydrogels showed greater fragmentation during handling and higher long-term swelling. In contrast, AF-12-derived hydrogels showed lower stiffness but better apparent cohesion and a more restricted swelling profile, consistent with enhanced long-range network connectivity derived from higher molecular weight. FTIR confirmed preservation of the characteristic functional groups of sodium alginate, whereas XRD provided qualitative evidence of residual crystalline inorganic phases. Selected-metal analysis by MP-AES detected Cu in both extracted alginates, while As was detected but not quantified only in AF-12; Cd and Pb were not detected under the analytical conditions employed. Overall, the results establish a route-dependent structure-property relationship in which extraction conditions govern yield, chain preservation, block architecture, viscoelastic response, swelling behavior, and preliminary contaminant profile. These findings support beach-cast Sargassum as a promising source of research-grade sodium alginate, while emphasizing that further purification, expanded contaminant profiling, arsenic speciation, biological evaluation, and direct mechanical testing are required before any food, biomedical, pharmaceutical, or environmental application can be proposed. Full article

Chilling injury is a major problem limiting the postharvest storage and marketability of mango fruit at low temperature. The present study investigated the individual and combined effects of sodium nitroprusside (SNP), L-arginine (Arg) and salicylic acid (SA) on chilling tolerance, regulation of oxidative stress and the postharvest quality of ‘Keitt’ mango fruit stored at 5 ± 1 °C for 28 days followed by 4 days of shelf life at 23 °C. Fruits were pre-treated with 1 mM SNP, 1 mM Arg, 2 mM SA or their binary combinations before storage. The chilling injury, membrane damage, lipid peroxidation, protein oxidation and fruit softening were greatly enhanced by cold storage in untreated fruits. In contrast, all the treatments significantly ameliorated these deteriorative changes, and the combined treatments were superiorly effective. Among these, SNP + Arg was the most effective treatment, which reduced the chilling injury index from 4.05 in control fruits to 1.00 after shelf life, completely inhibiting the incidence of decay and reducing electrolyte leakage and malondialdehyde accumulation by 47.4 and 48.2%, respectively. The same treatment also maintained higher firmness, titratable acidity, visual appearance and ascorbic acid content than untreated fruits. The enhanced chilling tolerance was accompanied by increased antioxidant defense, as SNP + Arg significantly stimulated the activities of superoxide dismutase, catalase and peroxidase, but suppressed the activity of pectin methylesterase. Multivariate analyses, such as PCA, clustered heatmap and integrated stress index, demonstrated a strong negative relationship between oxidative stress markers and antioxidant metabolism. The results showed that combined SNP and Arg treatments enhanced chilling tolerance through increasing antioxidant capacity, preserving membrane integrity, and retarding ripening-related metabolism, which provides an effective way to maintain the postharvest quality of cold-stored mango fruit. Full article

Excessive application of chemical preservatives has raised increasing concerns regarding food safety and human health, prompting the search for safer natural alternatives. Lavender essential oil (LEO), a plant-derived antimicrobial agent, has been considered a promising substitute for synthetic preservatives, but its high volatility and poor water solubility limit its practical application. In this study, LEO nanoemulsions were fabricated via high-pressure homogenization using sodium caseinate (SC) and tea polyphenols (TPs) as composite emulsifiers. The preparation process was optimized using a three-factor, three-level orthogonal design, and the physicochemical properties, storage stability, and antibacterial activity were systematically investigated. The optimal preparation conditions were determined as an SC/TP mass ratio of 2:1, homogenization pressure of 70 MPa, and 7 homogenization cycles. The optimized nanoemulsion exhibited a droplet size of 130–210 nm, zeta potential of −30.89 mV, and encapsulation efficiency of 98.61%, with typical shear-thinning behavior and excellent storage stability. The percentage of free LEO remained below 7.5% within 15 days, indicating high stability, and the release behavior followed a zero-order kinetic model. The prepared nanoemulsion showed significant antibacterial activity against Staphylococcus aureus and Escherichia coli, with a minimum inhibitory concentration (MIC) of 62.5 μg/mL for both strains. This study confirms that the SC/TP composite interface can effectively stabilize LEO nanoemulsions, providing a theoretical basis for the development of natural and efficient food preservatives. Full article

This study employed sodium acetate trihydrate as the phase-change matrix and used a binary nucleating agent composed of disodium hydrogen phosphate dodecahydrate (DHPD) and borax (BX) to suppress supercooling. Sodium carboxymethyl cellulose (CMC) was used as a thickener to mitigate phase separation, and expanded graphite (EG) was introduced as a supporting matrix to enhance thermal conductivity. The composite phase-change material was prepared via melt blending. By means of thermal storage and release performance tests, differential scanning calorimetry and thermal conductivity tests, the effects of the binary nucleating agent ratio, CMC content and EG addition amount on phase-change thermal storage performance, supercooling degree, phase stability and thermal conductivity of the system were systematically investigated. The results indicated that the addition of 3.0 wt% DHPD and 2.0 wt% BX as the binary nucleating agent reduced the supercooling temperature from 20.52 °C to 1.92 °C; 1 wt% CMC effectively suppressed phase separation during thermal cycling; and the incorporation of 3.0 wt% EG increased the thermal conductivity of the composite to 2.92 times that of the pure hydrated salt. Full article

The present study evaluated the feasibility of replacing soy protein isolate with collagen and plasma proteins, either individually or in combination with κ-carrageenan, xanthan gum, and sodium tripolyphosphate, in an emulsion-type pork sausage, based on selected physicochemical, compositional, and textural quality parameters. Six formulations were produced, including a control and five reformulated variants in which soy protein was fully replaced by a mixture of collagen (1.88%) and plasma proteins (3.4%), used alone or supplemented with κ-carrageenan (1.0%), xanthan gum (0.2%), and sodium tripolyphosphate (0.2%). Moisture, protein, fat and collagen contents, color, pH, and sensory properties were analyzed after processing, while TBARS values and textural properties were assessed initially and after 30 days of storage. As a result of the reformulation, collagen content increased by 32.35–40.33%, while the collagen-to-protein ratio remained within legal limits (<20%). Soy protein replacement increased textural parameters, including hardness, cohesiveness, gumminess, chewiness, and shear force. Carrageenan and sodium tripolyphosphate enhanced texture and oxidative stability, whereas xanthan gum negatively affected texture quality and sensory acceptance. The formulation containing collagen, plasma proteins, carrageenan (1%) and sodium tripolyphosphate (0.2%) achieved the highest sensory scores, comparable to those of the control. The results show that replacing soy protein in an emulsion-type pork sausage is feasible when using optimized combinations of collagen, plasma proteins, and κ-carrageenan systems. Full article

A solar-assisted thermochemical cycle to store concentrated solar energy in solid elemental sulfur via the reversible interconversion of sulfuric acid and sulfur is being developed within the SULPHURREAL project. This process enables long-term, transportable energy storage through internal recycling of sulfur oxides. A central objective is to integrate SO₂ capture and conversion in separation-friendly steps that support closed-loop operation with minimal additives and limited downstream purification, while remaining compatible with industrial sulfuric acid and sulfur feedstocks. The method presented in this paper can also be feasible for SO₂ removal from fossil fuels and industrial emissions. With this purpose, indirect SO₂ conversion via bisulfite disproportionation was investigated using elemental sulfur as a heterogeneous auto-catalyst. Batch tests were performed in a pressurized, Teflon-lined autoclave with concentrated bisulfite solutions (3 M) at 140–180 °C for 3 h. Sodium bisulfite showed no conversions at 140–160 °C, whereas sulfur auto-catalysis was observed at T ≥ 170 °C. Ammonium bisulfite was also evaluated as a separable SO₂-capture intermediate; due to thermal instability, operation was limited to 170 °C, where sulfur formation remained detectable. For loop closure, NH₃ and H₂SO₄ must be recovered from the produced sulfate. This was addressed by reacting (NH₄)₂SO₄ with metal oxides in a tubular furnace at 500 °C. The evolved NH₃ was trapped in acid and quantified by ion chromatography. Near-quantitative NH₃ recovery (≈92–98%) was achieved with MgO and ZnO, and the corresponding metal sulfates were identified by XRD. These results support integrated process development and motivate kinetic and mass-balance studies toward continuous operation and scale-up. Full article

Biomass-derived carbons are promising sustainable anode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) because biomass is renewable, abundant, low-cost, and naturally diverse in composition and morphology. Lignocellulosic frameworks, intrinsic heteroatoms, and biomass-derived inorganic species can be converted through carbonization, activation, graphitization, and doping into carbon architectures with tunable porosity, carbon ordering, and surface chemistry. This review first summarizes the compositional and structural features of biomass precursors and explains how processing conditions convert them into carbon frameworks. Recent advances in biomass-derived carbon anodes are then discussed by comparing the distinct design requirements for LIBs and SIBs. For LIBs, accessible surface area, hierarchical porosity, heteroatom-derived active sites, and improved electronic conductivity are generally beneficial for enhancing Li⁺ storage and rate capability. In contrast, SIB hard carbons require controlled surface exposure, expanded turbostratic spacing, and closed or latent pores to improve Na⁺ storage reversibility and initial Coulombic efficiency. These comparisons emphasize that biomass-derived carbon anodes should be designed according to system-specific storage mechanisms rather than a universal carbon design strategy. Full article

Aqueous zinc-ion batteries offer a safe and economical platform for large-scale energy storage, yet vanadium oxide cathodes remain hindered by sluggish Zn²⁺ migration, poor electronic conductivity, and structural degradation during cycling. Herein, a PEDOT regulated interfacial engineering strategy is proposed to construct surface modified sodium vanadium oxide nanostructures with coordinated ion and electron transport. The 1P-NaVO cathode retains the layered framework while introducing a PEDOT-derived surface component that strengthens interfacial charge transfer and preserves accessible Zn²⁺ diffusion pathways, delivering 655 mAh g⁻¹ at 0.1 A g⁻¹. Kinetic analyses further reveal accelerated charge storage behavior, including an increased pseudocapacitive contribution, a low charge transfer activation energy of 20.6 kJ mol⁻¹, and improved Zn²⁺ diffusion, with D_Zn²⁺ values of approximately 10^−10.8 to 10^−9.8 cm² s⁻¹. Ex situ XRD and SEM disclose a reversible structural response during Zn²⁺ insertion and extraction, involving interlayer perturbation, local framework relaxation, transient electrolyte-derived surface species, and partial morphology recovery after recharge. These findings show that controlled PEDOT-derived surface regulation promotes efficient coupling between interfacial electron transfer and Zn²⁺ diffusion, offering a practical design principle for durable vanadium-based cathodes in aqueous zinc-ion batteries. Full article

Upcycling biomass waste into value-added battery materials is crucial for sustainable energy storage. Here, we transform coffee grounds into high-performance hard carbon (HC) anodes for sodium-ion batteries (SIBs) via a synergistic pre-oxidation and acetylene chemical vapor deposition (CVD) strategy, which effectively reduces open pores and promotes structural stabilization. The resulting material exhibits features consistent with a closed-pore architecture. Pre-oxidation incorporates oxygen-containing functional groups that template accessible pores and expand the interlayer spacing during carbonization. Subsequent CVD covers surface pores and contributes to the stabilization of the pore structure. The optimized HC (COF300&1300@C) exhibits a balanced set of structural features, including a low specific surface area (2.1 m² g⁻¹), expanded interlayer distance (0.391 nm), and a well-regulated pore system with reduced surface area and controlled pore size. As a result, it delivers a reversible capacity of 298 mAh g⁻¹ with an ICE of 70%, and remarkable cycling stability (97% capacity retention after 500 cycles at 1C). This study elucidates the synergistic mechanism of pre-oxidation and CVD in reducing open pores and stabilizing the pore architecture, thereby yielding characteristics indicative of closed-pore behavior, and providing a novel and efficient approach for designing high-performance biomass-derived hard carbons for energy storage. Full article

Cysteine proteases (bromelain, ficin, and papain) are widely used in biotechnology and medicine, but their application is limited by rapid autolysis and oxidative inactivation. This study aimed to develop effective supports for these enzymes based on graft copolymers of sodium alginate and poly(N-vinylpyrrolidone) (SA-g-PVP) and to elucidate the structure–property relationships governing immobilization efficiency, catalytic activity, and storage stability. Copolymers were synthesized via radical solution polymerization under optimized conditions. Enzymes were immobilized by physical adsorption, and the resulting complexes were characterized by Fourier-transform infrared (FTIR) spectroscopy, protein content assays, proteolytic and amidase activity measurements, and molecular docking. The graft copolymer with a smaller particle size in solution provided a larger accessible surface area, leading to higher bromelain and papain loading. Ficin showed the opposite trend due to its unique surface amino acid composition. Immobilization dramatically increased storage stability: half-life values for bromelain, ficin, and papain reached up to 20, 14, and 14 days, respectively, compared to 1–3 days for the free enzymes. Molecular docking revealed that the dense polymer shell stabilizes the enzyme tertiary structure by forming multiple contacts with internal cavities and tunnels, thereby preventing autolysis and conformational unfolding. Collectively, these findings demonstrate that SA-g-PVP copolymers are promising, non-toxic supports for cysteine proteases, with ficin showing up to 100% activity recovery, making them suitable for food, cosmetic, and biomedical applications. Full article

Water management in high-temperature and high-salinity reservoirs remains a critical challenge for oilfield operations, with conventional polymer gel systems exhibiting insufficient thermal stability and salt tolerance under extreme conditions. Here, we establish an integrated computational–experimental platform combining density functional theory (DFT) and molecular dynamics (MD) simulations to rationally design a novel AM/AMPS/AMB (Acrylamide/2-acrylamido-2-methylpropanesulfonic acid/sodium 3-acrylamido-3-methylbutanoate) terpolymer gel plugging agent tailored for the Tahe Oilfield (140 °C, Ca²⁺/Mg²⁺ 10,000 mg L⁻¹). Density functional theory (DFT) calculations of fourteen functional monomers identified AMB as the optimal candidate, achieving further hydrogen bond interactions that stabilize the crosslinked architecture under extreme conditions. This computational pre-screening reduced experimental iterations by over 60% and significantly shortened development cycles compared to conventional trial-and-error approaches. Experimentally, the optimized terpolymer exhibited a 40% increase in storage modulus (150 Pa) relative to AM/AMPS binary systems, 25% improvement in thermal stability (residual carbon at 300 °C), and plugging efficiency exceeding 92% in core flooding tests. Full article

To address the issue of CO₂ leakage induced by microcracks in cement sheaths during geological CO₂ storage, this study developed a multi-crosslinked CO₂-responsive preformed particle gel (MCCR-PPG) system. Using vinyl silica nanoparticles (VSNPs) as nano-crosslinkers and reinforcing agents, combined with CO₂-responsive monomers, sodium alginate, organic crosslinkers, and ionic crosslinkers, an intelligent plugging material with a quadruple crosslinking network was constructed. The optimal formulation was determined through single-factor experiments: the molar ratio of DMAA, VIM, and NVP was 2:2:1; the dosages of crosslinker MBA and initiator APS were each 0.5% of the total monomer molar amount; the concentration of CaCl₂ solution was 0.1 mol/L; and the VSNP content was 1 wt%. The results showed that the equilibrium swelling ratio of MCCR-PPGs in CO₂ acidic solution reached 3200%, which was 4.27 times that in deionized water, demonstrating excellent CO₂ responsiveness. Fracture plugging experiments further confirmed that the swollen gel formed a stable barrier within fractures, effectively preventing CO₂ channeling with a breakthrough pressure differential of 2.008 MPa, indicating excellent plugging performance. This study provides a critical material solution for wellbore integrity in CCUS applications and holds significant engineering value for preventing CO₂ leakage and ensuring storage safety. Full article