Search Results (2,950)

Background/Objectives: In-office bleaching commonly employs high concentrations of hydrogen peroxide (HP) or carbamide peroxide (CP), which may compromise enamel integrity. This in vitro paired-design study aimed to compare the chemical and mechanical effects of three commercial bleaching agents—Opalescence Boost (40% HP), Opalescence Quick (45% CP), and BlancOne Ultra+ (35% HP)—on human enamel. The null hypothesis assumed no significant differences between the control and treated samples. Given the ongoing debate over pH, active ingredients, and enamel impact, comparing whitening systems remains clinically important. Methods: Forty-two extracted teeth were assigned to three experimental groups (n = 14) with matched controls. Each underwent a single bleaching session per manufacturer protocol: Opalescence Boost (≤60 min), Opalescence Quick (15–30 min), and BlancOne Ultra+ (three light-activated cycles of 8–10 min). Enamel chemical changes were analyzed by Fourier transform infrared (FTIR) spectroscopy (phosphate and carbonate bands), and surface hardness by Vickers microhardness testing. Paired t-tests (α = 0.05) assessed statistical significance. Results: FTIR analysis revealed alterations in phosphate and carbonate bands for all agents, most notably for Opalescence Boost and BlancOne Ultra+. Microhardness testing showed significant reductions in enamel hardness for Opalescence Boost (control: 37.21 ± 1.74 Hv; treated: 34.63 ± 1.70 Hv; p = 0.00) and Opalescence Quick (control: 45.82 ± 1.71 Hv; treated: 39.34 ± 1.94 Hv; p < 0.0001), whereas BlancOne Ultra+ showed no significant difference (control: 51.64 ± 1.59 HV; treated: 51.60 ± 2.34 Hv; p = 0.95). Conclusions: HP-based agents, particularly at higher concentrations, caused greater enamel alterations than CP-based products. While clinically relevant, the results should be interpreted cautiously due to in vitro limitations and natural enamel variability. Full article

Understanding how energy use and economic activity shape carbon emissions is pivotal for achieving global climate targets. This study quantifies the dynamic nexus between disaggregated energy consumption, economic growth, and CO₂ emissions in India and China—two economies that together account for more than one-third of global emissions. Using annual data from 1990 to 2021, we implement Long Short-Term Memory (LSTM) neural networks, which outperform traditional linear models in capturing nonlinearities and lagged effects. The dataset is split into training (1990–2013) and testing (2014–2021) intervals to ensure rigorous out-of-sample validation. Results reveal stark national differences. For India, coal, natural gas consumption, and economic growth are the strongest positive drivers of emissions, whereas renewable energy exerts a significant mitigating effect, and nuclear energy is negligible. In China, emissions are dominated by coal and petroleum use and by economic growth, while renewable and nuclear sources show weak, inconsistent impacts. We recommend retrofitting India’s coal- and gas-plants with carbon capture and storage, doubling clean-tech subsidies, and tripling annual solar-plus-storage auctions to displace fossil baseload. For China, priorities include ultra-supercritical upgrades with carbon capture, utilisation, and storage, green-bond-financed solar–wind buildouts, grid-scale storage deployments, and hydrogen-electric freight corridors. These data-driven pathways simultaneously cut flagship emitters, decouple GDP from carbon, provide replicable models for global net-zero research, and advance climate-resilient economic growth worldwide. Full article

Given the urgent need to decarbonize the global energy system, green hydrogen has emerged as a key alternative in the transition to renewables. However, its production via electrolysis demands high water quality and raises environmental concerns, particularly regarding reject water discharge. This study employs an experimental and analytical approach to define optimal water characteristics for electrolysis, focusing on conductivity as a key parameter. A pilot water treatment plant with reverse osmosis and electrodeionization (EDI) was designed to simulate industrial-scale pretreatment. Twenty water samples from diverse natural sources (surface and groundwater) were tested, selected for geographical and geological variability. A predictive algorithm was developed and validated to estimate useful versus reject water based on input quality. Three conductivity-based categories were defined: optimal (0–410 µS/cm), moderate (411–900 µS/cm), and restricted (>900 µS/cm). Results show that water quality significantly affects process efficiency, energy use, waste generation, and operating costs. This work offers a technical and regulatory framework for assessing potential sites for green hydrogen plants, recommending avoidance of high-conductivity sources. It also underscores the current regulatory gap regarding reject water treatment, stressing the need for clear environmental guidelines to ensure project sustainability. Full article

Natural hydrogen is generated by fairly deep processes and/or in low-permeability rocks. In such contexts, fluids circulate mainly through the network of faults and fractures. However, hydrogen flows from these hydrogen-generating layers can reach sedimentary rocks with more typical permeability and porosity, allowing H₂ flows to spread out rather than be concentrated in fractures. In that case, three different H₂ transport modes exist: advection (displacement of water carrying dissolved gas), diffusion, and free gas Darcy flow. Numerical models have been run to compare the efficiency of these different modes and the pathway they imply for the H₂ in a sedimentary basin with active aquifers. The results show the key roles of these aquifers but also the competition between free gas flow and the dissolved gas displacement which can go in opposite directions. Even with a conservative hypothesis on the H₂ charge, a gaseous phase exists at few kilometers deep as well as free gas accumulation. Gaseous phase displacement could be the faster and diffusion is neglectable. The modeling also allows us to predict where H₂ is expected in the soil: in fault zones, eventually above accumulations, and, more likely, due to exsolution, above shallow aquifers. Full article

The main advantage of using biomass for energy generation is the reduction in carbon dioxide emissions. For a fast reduction effect, it is important to use biomass characterised by an annual growth cycle. These may be fallen leaves. The fuel properties of the leaves can change during the growth period. These changes can result from both the natural growth process and environmental factors—particulate matter adsorption. The main objective was to determine changes in the characteristics of leaves and needles during the growth period (from May to October). Furthermore, to determine the effect of adsorbed particulate matter, the washing process was carried out. Studies were carried out for three tree species: Norway maple, horse chestnut and European larch. Proximate and ultimate analysis was performed and mercury content was determined. During the growth period, beneficial changes were observed: an increase in carbon content and a decrease in hydrogen and sulphur content. The unfavourable change was a significant increase in ash content, which caused a decrease in calorific value. The increase in ash content was caused by adsorbed particulate matter. They were mostly absorbed by the tissues of the needle and leaves and could not be removed by washing the surface. Full article

The European Union promotes decarbonization in energy-intensive industries like glass manufacturing. Collaboration between industry and researchers focuses on reducing CO₂ emissions through hydrogen (H₂) integration as a natural gas substitute. However, to the best of the authors’ knowledge, no updated real-world case studies are available in the literature that consider the on-site implementation of an electrolyzer for autonomous hydrogen production capable of meeting the needs of a glass manufacturing plant within current technological constraints. This study examines a representative hollow glass plant and develops various decarbonization scenarios through detailed process simulations in Aspen Plus. The models provide consistent mass and energy balances, enabling the quantification of energy demand and key cost drivers associated with H₂ integration. These results form the basis for a scenario-specific techno-economic assessment, including both on-grid and off-grid configurations. Subsequently, the analysis estimates the levelized costs of hydrogen (LCOH) for each scenario and compares them to current and projected benchmarks. The study also highlights ongoing research projects and technological advancements in the transition from natural gas to H₂ in the glass sector. Finally, potential barriers to large-scale implementation are discussed, along with policy and infrastructure recommendations to foster industrial adoption. These findings suggest that hybrid configurations represent the most promising path toward industrial H₂ adoption in glass manufacturing. Full article

Hydrogen sulfide (H₂S) can be produced from the metabolism of foods containing sulfur in the gastrointestinal tract (GIT). At low doses, H₂S regulates the gut microbial community and supports GIT health, but depending on dose, age, and individual health conditions, it may also contribute to inflammatory responses and gut barrier dysfunction. Controlling H₂S production in the GIT is important for maintaining a healthy gut microbiome. However, research on this subject is limited due to the gaseous nature of the chemical and the difficulty of accessing the GIT in situ. In the present ex vivo experiment, we used a single-dose sodium sulfide preparation (SSP) as a H₂S precursor to test the effect of H₂S on the human gut microbiome across different age groups, including breastfed infants, toddlers, adults, and older adults. Metagenomic sequencing and metabolite measurements revealed that the development of the gut microbial community and the production of short-chain fatty-acids (SCFAs) were age-dependent; that the infant and the older adult groups were more sensitive to SSP exposure; that exogeneous SSP suppressed SCFA production across all age groups, except for butyrate in the older adult group, suggesting that H₂S selectively favors specific gut microbial processes. Full article

The current work is established with the object of modifying the source of Fenton system and substituting iron source as a catalyst with magnetite/potato peels composite material (POT400-M) to be an innovative solar photocatalyst. The structural and morphological characteristics of the material are assessed through X-ray diffraction (XRD) and scanning electron microscopy (SEM). The technique is applied to treat oil spills that pollute seawater. The effectiveness of the operating parameters is studied, and numerical optimization is applied to optimize the most influential parameters on the system, including POT400-M catalyst (47 mg/L) and hydrogen peroxide reagent (372 mg/L) at pH 5.0, to maximize oil removal, reaching 93%. Also, the aqueous solution and wastewater temperature on the oxidation reaction is evaluated and the reaction exhibited an exothermic nature. Kinetic modeling is evaluated, and the reaction is found to follow the second-order kinetic model. Thermodynamic examination of the data exhibits negative enthalpy (ΔH′) values, confirming that the reaction is exothermic, and the system is verified to be able to perform at the minimal activation energy barrier (−51.34 kJ/mol). Full article

This study aimed to determine the impact of natural fermentation time on the chemical composition and antioxidant activities of cassava flour. Samples of flour were fermented for intervals of 12, 24, and 48 h and compared with the control (0 h). The results indicated clear differences in the chemical composition of these samples. The pH value was reduced, TTA increased, and TSS decreased. This is due to the action of lactic acid bacteria during fermentation. The TPC value also increased with fermentation time, achieving 2.95 mg GAE/g after 48 h, compared to 1.35 mg GAE/g initially. Antioxidant activities improved significantly; total antioxidant capacity surged from 23.50 µmol TE/g to 69.81 µmol TE/g over the 48 h fermentation period, based on ABTS, DPPH, and FRAP assays. Protein content also improved significantly, increasing from 1.82% to 3.10%, while the hydrogen cyanide content declined from 25.14 mg/100 g to 5.34 mg/100 g, signifying reduced nutritional risk. An increase in minerals was also noted, with calcium showing the highest concentration of 41.35 mg/100 g after 48 h of fermentation. These findings demonstrate the effectiveness of fermenting cassava flour by enhancing its chemical composition and antioxidant properties while lowering antinutrients, which improves its value in functional foods. Full article

This study investigates ground deformations in the southeastern Po Plain (northern Italy), focusing on the Bologna area—a densely populated region affected by natural and anthropogenic subsidence. Ground deformations in the area result from geological processes (e.g., sediment compaction and tectonic activity) and human activities (e.g., ground water production and underground gas storage—UGS). We apply a multidisciplinary approach integrating subsurface geology, ground water production, advanced differential interferometry synthetic aperture radar—DInSAR, gas storage data, and land use information to characterize and analyze the spatial and temporal variations in vertical ground deformations. Seasonal and trend decomposition using loess (STL) and cluster analysis techniques are applied to historical DInSAR vertical time series, targeting three representatives areas close to the city of Bologna. The main contribution of the study is the attempt to correlate the lateral extension of ground water bodies with seasonal ground deformations and water production data; the results are validated via knowledge of the geological characteristics of the uppermost part of the Po Plain area. Distinct seasonal patterns are identified and correlated with ground water production withdrawal and UGS operations. The results highlight the influence of superficial aquifer characteristics—particularly the geometry, lateral extent, and hydraulic properties of sedimentary bodies—on the ground movements behavior. This case study outlines an effective multidisciplinary approach for subsidence characterization providing critical insights for risk assessment and mitigation strategies, relevant for the future development of CO₂ and hydrogen storage in depleted reservoirs and saline aquifers. Full article

Anaerobic digestion (AD) has long been valued for producing a biogas–digestate pair, yet its profitability is tightening. Next-generation AD biorefineries now position syngas both as a supplementary feedstock and as a springboard to capture high-value intermediates, hydrogen (H₂) and volatile fatty acids (VFA). This review dissects how complex natural consortia “decide” between hydrogenogenesis and acetogenesis when CO, H₂, and CO₂ co-exist in the feedstocks, bridging molecular mechanisms with process-scale levers. The map of the bioenergetic contest between the biological water–gas shift reaction and Wood–Ljungdahl pathways is discussed, revealing how electron flow, thermodynamic thresholds, and enzyme inhibition dictate microbial “decision”. Kinetic evidence from pure and mixed cultures is integrated with practical operating factors (gas composition and pressure, pH–temperature spectrum, culture media composition, hydraulic retention time, and cell density), which can bias consortia toward the desired product. Full article

Organic acids, as natural metabolites, play crucial roles in human metabolism and health. Tumor Necrosis Factor (TNF), a pivotal mediator in immune regulation and inflammation, is a key therapeutic target. We evaluated ten organic acids as TNF modulators using in silico molecular docking, followed by detailed ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) profiling and molecular dynamics (MD) simulations for three lead candidates: gallic, aconitic, and crocetin acids. Their effects on TNF gene expression were then assessed in vivo using a mouse leukocyte model. The in silico results indicated that crocetin had the highest TNF binding affinity (−5.6 to −4.6 kcal/mol), while gallic acid formed the most stable protein-ligand complex during MD simulations, and aconitic acid established hydrogen bond interactions. ADMET analysis suggested potential pharmacokinetic limitations, including low permeability. Contrasting its high predicted binding affinity, in vivo gene expression analysis revealed that crocetin stimulated TNF synthesis, whereas gallic and aconitic acids acted as inhibitors. This research explores organic acids as potential TNF modulators, highlighting their complex interactions and providing a foundation for developing these compounds as anti-inflammatory agents targeting TNF-mediated diseases. Full article

Geological storage is an integral element of the green energy transition. Geological formations, such as aquifers, depleted reservoirs, and hard rock caverns, are used mainly for the storage of hydrocarbons, carbon dioxide and increasingly hydrogen. However, potential adverse effects such as ground movements, leakage, seismic activity, and environmental pollution are observed. Existing research focuses on monitoring subsurface elements of the storage, while on the surface it is limited to ground movement observations. The review was carried out based on 191 research contributions related to geological storage. It emphasizes the importance of monitoring underground gas storage (UGS) sites and their surroundings to ensure sustainable and safe operation. It details surface monitoring methods, distinguishing geodetic surveys and remote sensing techniques. Remote sensing, including active methods such as InSAR and LiDAR, and passive methods of multispectral and hyperspectral imaging, provide valuable spatiotemporal information on UGS sites on a large scale. The review covers modelling and prediction methods used to analyze the environmental impacts of UGS, with data-driven models employing geostatistical tools and machine learning algorithms. The limited number of contributions treating geological storage sites holistically opens perspectives for the development of complex approaches capable of monitoring and modelling its environmental impacts. Full article

Construction wood has a high economic value, and its construction waste also has multiple consumption values. Natural wood has many advantages, such as thermal, environmental, and esthetic properties; however, wood sourced from artificial fast-growing forests is found to be deficient in mechanical strength. This shortcoming makes it less competitive in certain applications, leading many markets to remain dominated by non-renewable materials. To address this issue, various modification methods have been explored, with a focus on enhancing the plasticity and strength of wood. Studies have shown that hydrogen bonds in the internal structure of wood have a significant impact on its operational performance. Whether it is organic modification, inorganic modification, or a combination thereof, these methods will lead to a change in the shape of the hydrogen bond network between the components of the wood or will affect the process of its breaking and recombination, while increasing the formation of hydrogen bonds and related molecular synergistic effects and improving the overall operational performance of the wood. These modification methods not only increase productivity and meet the needs of efficient use and sustainable environmental protection but also elevate the wood industry to a higher level of technological advancement. This paper reviews the role of hydrogen bonding in wood modification, summarizes the mechanisms by which organic, inorganic, and composite modification methods regulate hydrogen bond networks, discusses their impacts on wood mechanical properties, dimensional stability, and environmental sustainability, and provides an important resource for future research and development. Full article

In this study, a composite film with dual antioxidant and antibacterial properties was prepared by combining 2% chitosan and 7% gelatin (2:1, w:w), with D-carvone (0–4%) as the primary active component. The effect of D-carvone content on the performance of the composite films was systematically investigated. The results showed that adding 1% D-carvone increased the water contact angle by 28%, increased the elongation at break by 35%, and decreased the WVTR by 18%. FTIR and SEM confirmed that ≤2% D-carvone uniformly bonded with the substrate through hydrogen bonds, and the film was dense and non-porous. In addition, the DPPH scavenging rate of the 1–2% D-carvone composite film increased to about 30–40%, and the ABTS⁺ scavenging rate increased to about 35–40%; the antibacterial effect on Escherichia coli and Staphylococcus aureus increased by more than 70%. However, when the addition amount was too high (exceeding 2%), the composite film became agglomerated, microporous, and phase-separated, affecting the film performance, and due to its own taste, it reduced the sensory quality of the noodles. Comprehensively, the composites showed better performance when the content of D-carvone was 1–2% and also the best effect for freshness preservation in Xinjiang ramen. This study provides a broad application prospect for natural terpene compound-based composite films in the field of high-moisture, multi-fat food preservation, and provides a theoretical basis and practical guidance for the development of efficient and safe food packaging materials. In the future, the composite film can be further optimized, and the effect of flavor can be further explored to meet the needs of different food preservation methods. Full article