Search Results (5,850)

The dielectric performance of power transformer insulation systems is strongly influenced by the type of cellulose paper, the impregnating dielectric liquid, and the paper moisture content. This study evaluates the moisture-dependent dielectric response of three cellulose insulating papers, Kraft, Thermally Upgraded Kraft, and Diamond Printed Enhanced, impregnated with three dielectric liquids: mineral oil, a rapeseed-based natural ester, and a Palm Fatty Acid Ester. Paper samples were first conditioned at controlled moisture contents ranging from 1% to 5%, then impregnated under stabilized conditions, and finally characterized by Frequency Domain Spectroscopy. The results show that increasing the moisture content produces a systematic rise in the dielectric dissipation factor, indicating higher dielectric losses and reduced insulation performance. The relative dielectric benefit of the ester liquids was strongly dependent on paper type, moisture content, and frequency. This paper-dependent behavior was particularly pronounced for Kraft and Thermally Upgraded Kraft papers. Finally, laboratory-derived moisture-dependent 50 Hz tan δ crossover points were identified as dielectric indicators for retrofilling assessment. These findings provide comparative dielectric information for the investigated paper–liquid insulation systems and may support preliminary retrofilling assessment under controlled laboratory conditions. Full article

Background/Objectives: This study characterized compositional variation among 996 foods and beverages retained from the Universidad San Francisco de Quito Food Chemical Composition Table after record-level quality control. Methods: Nineteen nutritional variables were evaluated using descriptive statistics, heteroscedastic one-way analysis of variance, rank correlations, principal component analysis, and hierarchical clustering. Missingness was substantial and non-random across food groups; 427 records contained all 19 variables and were used for multivariate analyses. Results: Welch tests with Holm correction identified food-group differences for all variables, although the magnitude of group separation ranged from small for vitamin A (η² = 0.029, 95% CI 0.016–0.061) to large for carbohydrates (η² = 0.590, 95% CI 0.555–0.632) and energy (η² = 0.588, 95% CI 0.530–0.654). Spearman analysis showed strong expected compositional associations between total fat and monounsaturated fatty acids (ρ = 0.956) and between total fat and saturated fatty acids (ρ = 0.937), together with non-arithmetic associations involving protein, phosphorus, zinc, cholesterol, and vitamin B12. Parallel analysis retained four principal components, which explained 61.4% of total variance; the first two accounted for 40.2% and primarily represented energy-lipid-mineral covariation and lipid composition. Ward clustering in the full 19-dimensional standardized space supported a three-cluster solution (silhouette = 0.482; median subsampling adjusted Rand index = 0.845), comprising a broad mixed profile, a fiber- and mineral-dense profile, and an oil-dominant profile. Conclusions: These results describe compositional patterns within the USFQ database and provide a reproducible basis for database harmonization, nutrient profiling, and hypothesis generation. They do not estimate dietary intake, food availability, nutritional adequacy, or health outcomes in the Ecuadorian population. Full article

Owing to their high nutritional value, functional proteins, and low environmental impact, legume proteins have emerged as sustainable alternatives to animal proteins. However, their broader utilization is constrained by antinutritional factors (ANFs), which can adversely affect protein digestibility, mineral bioavailability, and techno-functional features. Fermentation has appeared as a promising approach to overcoming these limitations. Through microbial and enzymatic activities, fermentation can reduce ANFs, modify protein structures, and promote proteolysis, generating peptides and free amino acids that may improve digestibility, bioavailability, and functional properties. This review critically explores the effects of fermentation on legume proteins, concentrating on ANF reduction, protein degradation and structural modification, proteolysis, and their consequences for nutritional and techno-functional properties. Particular attention is given to protein hydrolysis and peptide generation, as well as the limitations and potential trade-offs of fermentation, including extreme proteolysis, loss of desirable functional properties, unwanted sensory changes, variability among strains and substrates, and prolonged processing. The review also discusses the incorporation of fermented legume proteins into relevant food systems, with emphasis on their functional performance and application potential. Finally, current knowledge gaps and future research priorities are highlighted to support the development of controlled fermentation strategies for nutritionally improved, functionally tailored, and industrially feasible legume protein ingredients. Full article

In this study, the application of the boron-doped diamond (BDD) electrode for electrochemical removal of clavulanic acid was investigated. The studied pharmaceutical is one of the most commonly prescribed β-lactamase inhibitors, which raises concerns about its impact on the spread of antibiotic resistance, as well as environmental toxicity. Preliminary experiments conducted in buffered solutions showed that neutral pH ensures substantially higher degradation rates than basic and acidic conditions. Further studies featuring standardized humic substances revealed that the presence of dissolved organic matter can even improve the process’s performance, resulting in over 99% degradation achieved within 30 min of the electrooxidation experiment. Two detected intermediates were identified as the products of a β-lactam ring cleavage, which supposedly led to the loss of enzyme inhibiting properties. Total organic carbon (TOC) analysis (namely the non-purgeable carbon—NPOC—assay) showed that the time necessary to fully mineralize clavulanic acid is significantly longer than to degrade it. Nevertheless, BDD electrodes can be successfully applied for the removal of the studied compound from aquatic environments, which confirms their suitability as a part of water treatment systems. Full article

Lignocellulosic biomass recalcitrance remains a major challenge for the development of integrated biorefineries, necessitating efficient and selective pretreatment strategies. In this study, the influence of three acid catalyst systems, namely sulphuric acid (mineral acid), p-toluenesulphonic acid (pTSA; hydrotropic organic acid), and a ChCl:pTSA (1:1 molar ratio) binary catalyst system, prepared as an acidic deep eutectic solvent (DES) precursor and employed at a working concentration of 150 mM, on the organosolv fractionation of pigeon pea (Cajanus cajan) stalk was systematically investigated under identical operating conditions. All catalyst systems exhibited comparable delignification efficiencies (79.33–81.55%), cellulose retention (88.45–98.9%), and xylan removal (>95.51%), indicating similar biomass deconstruction at equivalent nominal acid equivalents. However, notable differences were observed in lignin recovery. The ChCl:pTSA resulted in the highest lignin recovery (65.9%), followed by pTSA (62.41%) and sulphuric acid (51.82%). Structural characterisation of the cellulose-rich and lignin-rich fractions by SEM, FTIR, XRD, ${}^1$H NMR, and TGA confirmed extensive lignin and hemicellulose removal while preserving the cellulose framework. The results indicate that catalyst formulation influences organosolv fractionation beyond nominal proton loading alone. While all catalyst systems effectively fractionated pigeon pea stalk, pTSA provided a competitive catalyst performance, combining high delignification and lignin recovery without the addition of ChCl, although its cellulose retention was lower than that obtained with sulphuric acid. The ChCl–pTSA system produced the highest numerical lignin recovery, although this was not statistically different from pTSA. The lower apparent molecular weight of the ChCl–pTSA-derived lignin further suggests that catalyst formulation may influence the subsequent reaction and recovery pathways of solubilised lignin, although the specific molecular mechanism remains unresolved. Full article

High-purity quartz (HPQ) is an essential material for photovoltaic, semiconductor, optical fiber, and advanced glass industries. However, natural quartz commonly contains gangue minerals, inclusions, and lattice impurities, and therefore requires deep purification. Owing to its ability to dissolve impurity-bearing components, acid leaching is widely adopted for quartz purification. This review critically summarizes recent advances in the mechanisms and enhancement strategies of acid purification of quartz sand. The partitioning characteristics of impurities in quartz are discussed; fundamental mechanisms of acid leaching are then reviewed. Particular attention is given to the differences between non-HF acid systems and HF-containing systems. Process enhancement strategies, including mechanical activation, thermal pretreatment, pressure leaching, and ultrasound-assisted leaching, are critically discussed. These strategies improve impurity accessibility, accelerate mass transfer, and improve reaction kinetics. This review provides guidance for the design of efficient, selective, and sustainable acid purification for HPQ production. Full article

Prunus spinosa L. (blackthorn) is a widely distributed wild fruit species in Romania with considerable, yet underexplored, potential as a functional food ingredient and natural source of bioactive compounds. This study aimed to characterize the phytochemical composition, mineral and contaminant profiles, and antioxidant capacity of P. spinosa fruits collected from five sites in the Cluj region with contrasting land-use conditions (forest-edge, rural, suburban, and roadside). Fruits were harvested in three sampling campaigns (October 2018, October 2019, and November 2019). Analytical determinations included total polyphenol content, antioxidant capacity, fatty acid methyl esters (FAMEs), dietary fibers, chlorophyll, water content, polycyclic aromatic hydrocarbons (PAHs, 15 congeners), and metal concentrations (ICP-OES/MS). A composite Ecotoxic Pressure Index (EPI) integrating metal and PAH data was computed per site. Total polyphenol content ranged from 124 to 1172 mg GAE·kg⁻¹ DW, while antioxidant capacity ranged from 116 and 1184 µg AAE·mg⁻¹. One-way ANOVA revealed significant location effects on Cu, Zn, Mn, Ca, Mg, Na and K (p < 0.05). PCA (65–70% explained variance) discriminated rural/forest-edge samples (high polyphenols, low EPI) from urban/roadside samples (elevated metals and PAHs). Multiple linear regression demonstrated that polyphenols were the dominant positive predictor of antioxidant capacity (β = +0.78, p < 0.001), while Fe and total PAHs were inversely associated with antioxidant capacity (β = −0.31 and −0.28, respectively; R² = 0.80). The observed biochemical and contaminant profiles varied according to geographical origin and land-use context, although these associations cannot be attributed exclusively to pollution exposure. Rural and forest-edge samples showed favorable descriptive profiles for several bioactive parameters, but further controlled studies are required before site-specific superiority for functional food applications can be established. Full article

Driven by the escalating worldwide consumption of animal-sourced commodities, the livestock industry faces intensified constraints regarding its ecological consequences, encompassing large-scale deforestation, elevated greenhouse gas emissions, progressive soil deterioration, and the suboptimal management of hydrological resources. In response to these challenges, the concept of sustainable livestock husbandry integrates production practices with environmental management strategies designed to conserve biodiversity, optimize resource use, and reduce emissions. The objective of this review is to emphasize the significance of sustainable cervid farming as an integral element of contemporary food supply chains, comprehensively addressing its environmental, production, and nutritional dimensions. A comprehensive assessment of current scholarly articles from Scopus, Web of Science, and Google Scholar was performed to explore topics concerning eco-conscious livestock practices, non-conventional farming models, organic rearing, animal well-being, and the evolution of deer breeding. Particular attention was paid to the role of permanent grasslands in venison production, soil protection, carbon sequestration, and biodiversity preservation. The nutritional value of red deer and fallow deer meat and its significance in sustainable food systems are also outlined. As indicated by the analysis of available research findings, extensive cervid farming based on the use of permanent grasslands and local feed resources can reduce environmental pressures through support of landscape conservation, preservation of ecosystem functions, and efficient utilization of biomass that is inedible for humans. Venison is shown to be a valuable source of high-quality protein, minerals, and essential fatty acids, which meets growing consumer demands for high-quality food. The literature review has confirmed that properly managed cervid farming can be an important element of sustainable food production systems combining production goals with environmental protection and animal welfare. It also emphasizes the need for further research into the environmental, economic, and social aspects of this branch of animal production. Full article

Increasing fertilizer costs, climate-related stresses, and soil degradation caused by the prolonged use of chemical fertilizers threaten the sustainability of agricultural production. Organic soil amendments offer a promising approach to restoring soil health while reducing dependence on synthetic inputs. This study evaluated the combined effects of biochar and organic fertilizer on soil health and soybean (Glycine max L.) productivity under acidic soil conditions. During the 2024 growing season, a greenhouse pot experiment was conducted using a completely randomized design (CRD) comprising seven treatments. Each treatment was replicated three times, resulting in a total of 21 pots. The treatments consisted of different combinations of biochar (B) and organic fertilizer (F), applied at rates of grams per 10.5 kg of soil: control (B0F0), B35F70, B35F105, B35F140, B70F70, B70F105, and B70F140. Treatment means were compared using the Least Significant Difference (LSD) test at p < 0.05. The results showed that the highest soil pH value (5.41) was recorded under the B35F70 treatment at 45 days after amendment of the acidic soil. Application of the B35F140 treatment resulted in a significant increase (p < 0.05) in electrical conductivity (0.23 mS cm⁻¹) compared with the control. Soil organic matter and available phosphorus reached their highest values under B70F140, at 5.25% and 13.87 mg kg⁻¹, respectively, and were significantly greater than those in the control treatment. Soil available iron (Fe) and manganese (Mn) concentrations also increased significantly (p < 0.05) compared with the control, with the B35F70 and B70F70 treatments resulting in the highest Fe (371.29 mg kg⁻¹) and Mn (37.77 mg kg⁻¹) concentrations, respectively. At 100 days after amendment of the reddish-brown acidic soil, exploratory Pearson correlation analyses were conducted to examine relationships between soil health indicators and soybean performance. Soil available phosphorus and potassium exhibited positive associations with soil pH (r = 0.69 and r = 0.65, respectively; p < 0.01). Soybean growth traits, including plant height and number of leaves, were positively associated with seed yield (r = 0.56 and r = 0.77, respectively; p < 0.01). Furthermore, seed yield was positively correlated with SPAD values (r = 0.80, p < 0.01), soil pH (r = 0.56, p < 0.01), available K (r = 0.68, p < 0.01), and Mg (r = 0.47, p < 0.05). Principal component analysis (PCA) further demonstrated clear treatment clustering and consistent positive relationships among soil properties, plant growth traits, and soybean yield variables. The control treatment was clearly separated from all biochar-organic fertilizer treatments along PC1. Among all treatments, B35F140 (3.33 g biochar kg⁻¹ soil + 13.33 g organic fertilizer kg⁻¹ soil) showed the strongest positive association with soil health and plant growth and produced the highest soybean seed yield (10.77 g plant⁻¹). Overall, the combined use of biochar and organic fertilizer improved soil health, soybean growth, and yield, demonstrating its potential as a sustainable strategy for enhancing soybean productivity under acidic soil conditions. Full article

Mussels are a nutritionally valuable and environmentally sustainable seafood, yet how geographical origin and farming environment shape their sensory and nutritional quality remains insufficiently characterized across European production contexts. This study compared mussels from three contrasting European farming areas, Ireland (Mytilus edulis), Norway (Mytilus edulis) and Italy (Mytilus galloprovincialis), integrating Quantitative Descriptive Analysis (QDA^®) with proximate composition, fatty acid, amino acid and mineral analyses. Italian mussels showed higher protein, lipid, carbohydrate and amino acid content together with the most intense and persistent umami taste, correlated with glutamic and aspartic acid content. Irish mussels were characterized by the highest moisture and iron content, associated with greater exudate release and salty/briny notes, while Norwegian mussels showed the lowest ash and amino acid content alongside greater bitterness, linked to omega-3 fatty acid content. These findings indicate that local environmental conditions shape origin-associated tendencies in the nutritional and sensory profile of farmed mussels, supporting the concept of a bivalve ‘marine terroir’ with potential applications for origin-based quality valorization. Full article

The global seafood industry generates substantial quantities of processing by-products such as heads, viscera, skin, bones, scales, and shells. These residues represent an underutilized resource rich in proteins, lipids, minerals, enzymes, and polysaccharides. Conventional valorization approaches such as chemical extraction, wet rendering, and enzymatic hydrolysis have been used to recover valuable compounds from seafood waste. However, conventional methods often involve high chemical consumption, long processing times, and environmental concerns. Green extraction technologies have emerged as promising alternatives, with subcritical water extraction (SWE) gaining significant attention due to its unique properties and ability to simultaneously extract and convert biomass components. This review provides a comprehensive overview of the valorization of seafood processing wastes using SWE. Particular emphasis is placed on the physicochemical properties of subcritical water, the reaction mechanisms governing the hydrolysis and transformation of proteins, lipids, and polysaccharides, and the key parameters influencing extraction performance. Recent advances in the recovery of value-added products such as amino acids, bioactive peptides, protein hydrolysates, omega-3-rich oils, chitin derivatives, and mineral-rich materials are summarized. In addition, the integration of SWE with complementary technologies such as supercritical CO₂ extraction, enzymatic hydrolysis, and hydrothermal carbonization is examined as a strategy for developing integrated seafood biorefineries. Full article

Salinity is a key driver of microbial community structure and function in salt lake ecosystems, yet how it shapes functional genes involved in carbon (C), nitrogen (N), and phosphorus (P) cycling remains poorly understood. We collected metagenomic samples along a natural salinity gradient in Yuncheng Salt Lake and examined how salinity was associated with microbial taxonomic and functional diversity and with C, N, and P cycling genes. Both diversity metrics decreased significantly with increasing salinity and were positively correlated with each other. The composition and abundance of C, N, and P cycling genes differed significantly among the low-, medium-, and high-salinity groups. In carbon cycling, most carbon fixation genes were more abundant at higher salinity, whereas most carbon degradation genes were less abundant; within carbon fixation, reductive tricarboxylic acid (rTCA) cycle and Calvin cycle gene abundances were higher. In nitrogen cycling, nitrogen mineralization and assimilation genes were significantly more abundant. In phosphorus cycling, transporter and pyrimidine metabolism genes were more abundant, whereas the relative contribution of purine metabolism genes declined. Co-occurrence network analysis revealed dense positive co-occurrence associations among C, N, and P cycling genes, with mer, GLU, and ppk1 as highly connected genes. Mantel tests identified salinity and pH as the primary environmental factors associated with functional gene variation. These results suggest that salinity may regulate C, N, and P cycling genes partly by reshaping microbial community structure in salt lake ecosystems. Full article

Rare earth elements (REE) are critical to 21st-century technology, from electronics and defense applications to renewables and beyond. The processing of REE is primarily based on minerals (bastnasite, monazite, and xenotime), but alternative resources (coal ash, E-waste, and permanent magnets) are also gaining increasing interest. Adsorption remains one of the most efficient, environmentally friendly extraction methods despite its lengthy mixing time. In the present research article, a hemp biochar prepared by vacuum pyrolysis at 700 °C was examined for its applicability in the adsorption of selected REE (La³⁺, Nd³⁺, Dy³⁺) from synthetic solutions. An innovative technique, Resonant Vibratory Mixing (RVM), was applied to improve adsorption kinetics, with factors including time (5–30 min) and intensity (30–70%) at room temperature. Using the Thermo Scientific 4000 M shaker for mixing, the maximum adsorption capacities were 77.56 mg/g for Dy³⁺, 75.85 mg/g for La³⁺, and 72.65 mg/g for Nd³⁺ using 100 mg of hemp biochar and 10 mL solutions (1000 mg/L). The adsorption capacity of 100 mg hemp biochar was 79.79 mg/g for Dy³⁺, followed by 77.61 mg/g for La³⁺ and 75.75 mg/g for Nd³⁺, using RVM for only 40 min at 70% intensity. RVM increased the adsorption capacities of all REE in only 40 min. Surface and structural analyses were carried out using Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller analysis (BET), Zeta Potential, and Carbon/Hydrogen/Nitrogen (CHN) methods. The adsorption recoveries of all REE in the single-element system were higher than 98.5%. However, in a multi-element system, the adsorption recoveries of La³⁺, Nd³⁺, and Dy³⁺ were 83.7%, 96.2%, and 99.2%, respectively, demonstrating that hemp biochar has low selectivity for Dy³⁺ and Nd³⁺. The adsorption process could be well described by the Langmuir isotherm and the pseudo-second-order kinetic model, indicating monolayer adsorption and chemical process involvement. Based on the characterization analysis of hemp biochar, electrostatic interaction was the dominant mechanism in this study. REE desorption using 0.5 M nitric acid was the most efficient, with >80% of REE recovered. The combination of hemp biochar as an adsorbent and RVM as a mixing technique demonstrated excellent performance in synthetic solutions; the reusability and application of hemp biochar to natural solutions require further study. Full article

Fish is a food of high nutritional value, being an important source of proteins, fat, vitamins, and essential minerals. Atlantic horse mackerel is also rich in omega-3 polyunsaturated fatty acids (n3-PUFAs), recognized for their benefits to cardiovascular and neurological health. However, this composition also makes it highly susceptible to lipid oxidation, reducing its shelf life. Oxidation is accelerated by high water activity and near-neutral pH, conditions common in fish and processed products such as fish burgers. This work aimed to develop fish burgers incorporated with bioactive extracts (protein hydrolysates from cod fish processing by-product—PH, or green tea extract—GTE) and study their shelf life. The PH was recovered from cod frames using subcritical water extraction, and GTE with hydro-alcoholic extraction. The fish burgers were prepared using minced fish meat incorporated with 1% (w/w) of extracts, in four formulations: (i) 1% (w/w) of PH; (ii) 1% (w/w) of GTE; (iii) a combination of both extracts at 0.5% (w/w) each; and (iv) control without extracts. Physical–chemical, antioxidant and microbiological analysis of the burgers was performed to evaluate their preservation over 6 days of refrigerated storage. Compared to the control, samples with only GTE or the combined GTE + PH presented a delay in oxidation (50% less in TBARS) and microbiological deterioration (reduction of 0.5–1.8 Log CFU/g in total psychrotropic microorganisms). No significant changes were observed in the fish burgers incorporated with only PH. The results demonstrate that the incorporation of bioactive extracts has potential in reducing oxidative degradation and improving microbiological stability in fish-based products; however, superior doses must be used. Moreover, the use of natural extracts aligns with current consumer demand for clean-label and functional foods. Full article

Carbon dioxide (CO₂) capture and storage technologies are key methods for mitigating the greenhouse effect. The development of high-performance adsorbents using abundant natural minerals represents a promising approach to achieving cost-effective CO₂ capture. In this work, we report a simple and scalable strategy for preparing two-dimensional (2D) porous nanosheets from the natural layered clay mineral vermiculite as the raw material, via liquid-phase exfoliation and acid etching. The clay-based 2D porous nanosheets exhibited a high specific surface area, a hierarchical porous structure, and mechanical and chemical stability. In the presence of the 2D porous nanosheets, the CO₂ capture and adsorption capacity were significantly enhanced. The gas adsorption properties of the porous nanosheets were investigated over a wide temperature range (25–75 °C), achieving a gas uptake capacity of 38.22 mmol/g (at 75 °C and 35 bar). Furthermore, an intrinsic relationship between the pore structure of the porous nanosheets and their gas adsorption performance was revealed. The maximum uptake capacity remained at approximately 36.40 mmol/g during five adsorption–desorption cycles conducted at 75 °C. This work provides a promising approach for further development of clay-derived adsorbents for CO₂ capture and may also offer useful implications for understanding CO₂ geological sequestration. Full article