Search Results (99,234)

The reuse of the finest fraction derived from recycled aggregate washing has been investigated for the manufacture of mortars. This practice contributes to the circular economy and lowers CO₂ emissions in the manufacturing of construction materials. A distinction was made between concrete-rich residues (RH) and mixed concrete–ceramic wastes (RHM). Chemical and mineralogical analyses of samples collected over a two-year period revealed consistent homogeneity over time. The RH residues are richer in CaO, primarily as calcite. Conversely, higher ceramic content in the waste correlates with increased SiO₂, Al₂O₃, and K₂O concentrations, predominantly as phyllosilicates and feldspars. Ettringite and portlandite occur in trace amounts. DTA-TG analysis reveals the presence of minor contents of portlandite and C-S-H gel. Mortars were prepared by replacing 10%, 20%, and 30% of Portland cement (OPC) with concrete-derived (RH) and mixed concrete–ceramic (RHM) wastes. At 10% and 20% substitution, both wastes yielded similar strengths, confirming their high potential for masonry mortars without prior treatment. However, at 30% replacement, RH provided markedly higher compressive and flexural strengths than RHM, likely due to a greater presence of the C-S-H gel phase in concrete waste. While 10% and 20% replacements successfully meet the 70% Strength Activity Index (SAI) threshold, a 30% limit severely reduces strength. Consequently, substitutions of 30% or higher require mechanical or thermal activation to enhance CDW reactivity. Given the minimal performance gap between RH and RHM, processing mixed CDW streams uniformly is recommended to maximize economic viability and ensure batch homogeneity in industrial washing plants. Full article

Increasing temperature is a major stress factor associated with climate change, strongly limiting agricultural productivity, particularly in sensitive crops such as tomato (Solanum lycopersicum L.). High temperatures promote the accumulation of reactive oxygen species (ROS), leading to oxidative damage and disruption of key physiological processes. Here, we evaluated whether desert-derived endophytic fungi differentially modulate oxidative stress responses in tomato plants exposed to heat stress. Plants were inoculated with either Talaromyces minioluteus or Serendipita indica and grown under control (22/19 °C) or heat stress conditions (35/19 °C). Heat stress reduced growth and increased oxidative damage, whereas endophyte inoculation mitigated these effects. Inoculated plants showed higher shoot and root biomass, lower levels of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), and enhanced enzymatic and non-enzymatic antioxidant systems, including increased activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), as well as greater accumulation of phenolic compounds and flavonoids. However, the magnitude and direction of these responses depended on the endophyte species. Overall, endophytic fungi modulated ROS homeostasis through coordinated enzymatic and non-enzymatic antioxidant mechanisms. These findings indicate that desert endophytic fungi enhance tolerance to heat stress through endophyte-specific regulation of oxidative balance, highlighting their potential to improve crop resilience under climate change. Full article

The extensive use of synthetic polymers has raised significant environmental concerns due to their non-biodegradable nature and persistence in the environment. Cellulose-based materials have attracted considerable interest owing to their excellent inherent properties which enable their wide range of industrial and biomedical applications. In this study, an integrated approach (hydrothermal process, organosolv delignification and chlorine-free bleaching) was evaluated to obtain high-purity cellulose fiber from sugarcane bagasse (SCB). The untreated SCB was first subjected to hydrothermal process under varying experimental conditions defined by a central composite design (170–190 °C, 30–50 min) using a solid-to-liquid ratio of 1:10 (w/v). The hydrothermally pretreated solid was subsequently delignified using an organosolv process with an aqueous solution of 40% (v/v) ethanol and 0.1% (w/v) NaOH at 180 °C for 20 min. Finally, the organosolv delignified SCB was bleached with 1% (v/v) H₂O₂ and 1% NaOH (w/v) at 80 °C for 1 h. The bleached cellulose fiber exhibited a composition of 97.79 ± 0.19% cellulose, 1.10 ± 0.14% lignin and 0.23 ± 0.13% hemicellulose. XRD analysis displayed a notable increase in the crystallinity index from 52.2% in untreated SCB to 70.7% in the bleached cellulose fibers (BCF). Furthermore, FTIR revealed the disappearance of characteristic lignin and hemicellulose peaks at 1729, 1602, 1512 and 1240 cm⁻¹ while the intensity of cellulose bands including the crystallinity-associated peaks at 1432 and 1320 cm⁻¹ were preserved. The SEM images further confirmed significant transformation with distorted vascular tissue and exposed cellulose fibrils indicating extensive defibrillation. Full article

Soft piezoelectric electronic skins are expected to work reliably under repeated joint bending, where both stretchability and stress transfer efficiency are important. In this work, a BaTiO₃/PDMS piezoelectric electronic skin, denoted as BPPE-skin, was prepared by a blade-coating method. Rather than only increasing the amount of piezoelectric filler, this study focuses on how the PDMS matrix composition affects the mechanical deformation and electrical response of the composite. The PDMS base-to-curing-agent ratio was adjusted from 5:1 to 30:1, and the BaTiO₃ loading was varied from 10 to 90 wt%. Tensile tests show that increasing the base-to-curing-agent ratio reduces the elastic modulus and improves stretchability, while excessive softening weakens effective stress transfer. As a result, the voltage output reaches its highest value at a 10:1 ratio. Increasing the BaTiO₃ content further enhances the output, mainly because more active piezoelectric particles participate in electromechanical conversion. The optimized film, containing 90 wt% BaTiO₃ with a 10:1 PDMS ratio, maintains good flexibility and can be attached conformally to different body joints. Tests on the knee, elbow, wrist, and fingers produce distinct voltage patterns during bending motions, indicating the potential of BPPE-skin for wearable, self-powered human motion monitoring. Full article

Optical interrogation of weak infrared molecular signatures from hazardous small molecules is important for environmental monitoring and industrial safety. However, these weak molecular responses are often difficult to distinguish using conventional far-field spectroscopy. Here, we theoretically investigate an Ag metal–insulator–metal (MIM) nanocavity as a cavity-length-engineered plasmonic platform for molecular resonance-plasmon coupling. The molecular response is incorporated through an effective-medium dielectric model for a surface-confined molecular population within the 1 nm nanogap. By tuning the cavity length, the bare cavity plasmon resonance can be matched to a selected infrared-active molecular resonance, converting weak molecular absorption responses into a finite-contrast spectral splitting in the simulated spectrum. SO₂, COCl₂, and H₂O are first investigated as representative systems, with optimized cavity lengths of 545, 404, and 190 nm, respectively. Using a unified 5% normalized dip-depth criterion, we identify the onset of spectral splitting and obtain local threshold molecular number densities of 4.47 × 10²⁴, 1.48 × 10²⁵, and 1.84 × 10²⁶ m⁻³, respectively. The same cavity-matching and threshold-evaluation procedure is further applied to NO₂, NH₃, PH₃, HF, HCN, and H₂S. These results provide a comparative theoretical framework for molecule-specific cavity design in MIM nanocavities. Full article

Tunnel lining concrete is prone to early-age cracking and leakage during service, which provides pathways for water and harmful ions and consequently threatens the safety and durability of tunnel structures. To improve the crack resistance and water penetration resistance of lining concrete, this study investigates the effects of steel fibers, a CaO-MgO composite expansive agent, and fly ash–slag replacement on workability, mechanical properties, ultrasonic pulse velocity, early-age cracking, and water penetration resistance. The results show that steel fibers had the most pronounced effect on crack-width control; at 1.0% steel fiber content, the total cracking area and water penetration height decreased by 71.9% and 68.2%, respectively. The composite expansive agent showed an optimum dosage of 10%, at which cracking resistance and water penetration resistance were both improved. The largest reduction in water penetration height was observed when slag was fully replaced by fly ash, with an 87.5% decrease. These findings provide a material-design reference for improving the crack resistance and durability of tunnel lining concrete under restrained early-age conditions. Full article

A tetraphenylethylene-based salen-type Schiff base ligand and its Fe(III) coordination complex were synthesized and characterized using spectroscopic, electrochemical, mass spectrometric, and single-crystal X-ray diffraction techniques. The ligand features an N₂O₂ donor set and was obtained via Schiff base condensation with ethylenediamine, while reaction with FeCl₃ afforded a di-μ-phenoxo-bridged dinuclear Fe(III) complex under mild conditions. Unlike previously reported Fe(III)-salen electrochromic systems, which are predominantly mononuclear and exhibit ligand-centered redox processes with limited modulation of intraligand electronic communication, the present system incorporates a rigid tetraphenylethylene scaffold and forms a centrosymmetric di-μ-phenoxo-bridged Fe(III) dimer. This structural motif enables coordination-induced electronic coupling between phenolate units, resulting in a distinct splitting of ligand-centered oxidation processes. Single-crystal X-ray diffraction confirmed a di-μ-phenoxo-bridged Fe(III) dimer with distorted octahedral geometry. Electrochemical studies show a quasi-reversible ligand-centered oxidation in the free ligand, which splits into two separate redox events upon complexation, indicating the emergence of electronically non-equivalent redox sites. Spectroelectrochemical analysis reveals the formation of phenoxyl radical species accompanied by ligand-centered intervalence charge–transfer transitions and the appearance of a near-infrared absorption band upon oxidation. A reversible color change from red to blue is observed, reflecting redox-driven modulation of the electronic structure. Overall, this work demonstrates that incorporation of a tetraphenylethylene-based salen framework and formation of a di-μ-phenoxo-bridged Fe(III) dimer enables coordination-triggered intraligand electronic communication, leading to fundamentally different redox behavior compared to previously reported Fe(III)-salen electrochromic complexes, while no reversible metal-centered redox processes were detected within the experimentally investigated potential window. Full article

Background: Among natural products, vanillin (Van), a major component of Vanilla planifolia, exhibits multiple bioactivities, including antimicrobial effects. Methods: In this study, Van, its analogues o-vanillin (oVan), iso-vanillin (iVan), ethylvanillin (eVan), and a library of newly synthesized derivatives were evaluated against Helicobacter pylori strains with distinct antibiotic susceptibilities. Time-kill kinetics, antibacterial spectrum, and viability in a normal gastric cell line GES-1, were also assessed. Results: Van showed minimal or no activity (MIC and MBC > 128 µg/mL), whereas structural modifications markedly improved anti-H. pylori activity, with MIC values as low as 4 µg/mL. Compounds 16V, 20oV, and 29eV were among the most potent (MIC₉₀ = 4–16 µg/mL). Activity depended on both the vanilloid core and substituent type. The compounds were inactive against representative Gram-negative and Gram-positive bacteria (MIC > 128 µg/mL). Selected compounds preserved viability in GES-1 cells. Hierarchical clustering, artificial neural clustering, and principal component analysis identified potency-related architectural motifs and strain-specific activity. Docking against H. pylori urease suggested that several compounds, particularly 16V, may interact with the enzyme, providing preliminary support for a possible involvement of this target. Conclusions: Systematic modification of the vanilloid scaffold generated selective and relatively non-cytotoxic anti-H. pylori hit compounds and confirmed the value of natural metabolites in antibacterial drug discovery. Full article

This investigation meticulously examines the influence of activation energy, thermophoresis, Brownian motion, and magnetic fields on the flow dynamics and heat transfer characteristics of a non-Newtonian hybrid nanofluid comprising aluminum oxide (Al₂O₃), copper (II) oxide (CuO), and ethylene glycol over a horizontally stretching porous wedge. This research addresses the imperative need for enhancing energy transfer and thermal management systems, which possess considerable technical significance and industrial relevance. The flow equations were formulated into ordinary differential equations through the use of similarity transformations, which in turn were solved numerically by employing the spectral relaxation (SR) scheme. The findings indicate that the Brownian motion, activation energy, wedge angle, and magnetic field intensity are pivotal determinants of the system’s flow and thermal behavior. In particular, an increase in the wedge angle correlates with an augmentation of the Nusselt number while concurrently diminishing the thermal and diffusion profiles. A comparative analysis of the current investigation and earlier scrutiny revealed that hybrid nanofluids enhance mass and energy transfer rates in both studies. The novelty of this investigation is anchored in its comprehensive exploration of magneto-flow dynamics and the characteristics of hybrid nanofluids within the context of porous wedge-shaped geometries and external magnetic influences. The findings of this study extend previous research by offering quantitative elucidation regarding how pivotal parameters, such as wedge angles, activation energy, thermophoresis, and Brownian motion, affect heat and mass transfer phenomena, thus laying a robust groundwork for the optimization of hybrid nanofluid applications in engineering and industrial environments. The results are in robust agreement with the existing body of literature, thereby affirming the contributions of this study to the academic discourse in the field. Full article

Glyphosate is among the most widely used herbicides worldwide, and its extensive application has led to increasing concerns regarding environmental contamination and potential risks to human health. The persistence of this compound in soil and aquatic environments has created an urgent demand for analytical methods that are rapid, reliable, and economically feasible. In the present study, a microconductometric sensing platform was developed for glyphosate determination using a PVC liquid membrane incorporating an [o-COSAN]⁻/glyphosate ion-pair complex deposited onto interdigitated electrodes. The proposed sensor provided a linear analytical response over the concentration range of 1.0 × 10⁻⁵ to 2.5 × 10⁻³ M, with a detection limit of 4 μM. The device also exhibited excellent analytical performance, with reproducibility and repeatability values of 3% and 8% (RSD), respectively. Furthermore, the sensor maintained stable performance for more than three months and showed a high degree of selectivity toward glyphosate when evaluated against potential interfering compounds, including AMPA and carbofuran. These results demonstrate the potential of the proposed sensing platform as a simple, sensitive, and cost-effective tool for glyphosate monitoring in environmental samples. Full article

The COVID-19 pandemic affected maternal mental health in the UK, increasing postpartum emotional distress. This scoping review identified forms of postpartum emotional distress (PPED) examined during the pandemic, the methodologies and assessment tools used, analytical approaches, reported limitations, future research directions, and overall findings. This review followed Arksey and O’Malley’s framework and the Joanna Briggs Institute scoping review guidelines. A comprehensive, keyword-based search strategy was applied across electronic databases, initially on 28 January 2023, and updated on 20 July 2023, and 3 September 2025. Strict inclusion criteria were used, and data from eligible studies were charted and synthesised. This review of 35 UK studies on postpartum emotional distress (PPED) during COVID-19 found a dominant focus on depression and anxiety, with other PPED forms largely neglected. Quantitative designs overwhelmingly outnumbered qualitative and mixed-method approaches. Common limitations included low sample diversity, reliance on online self-report surveys, cross-sectional designs, convenience sampling, and social-media-based recruitment. This review is the first to map research approaches used to explore postpartum emotional distress (PPED) during COVID-19 in the UK. The limitations and future research directions identified in this review highlight an urgent need for more diverse sampling, longitudinal study designs, qualitative research exploring women’s lived experience narratives of different forms of postpartum emotional distress, greater consideration of biopsychosocial factors, and evidence-based interventions. Full article

This study evaluated the effects of different LED spectral irradiance ratios on the growth, secondary metabolites, and essential oil characteristics of Ocimum × africanum Lour. cultivated for four weeks under controlled conditions. Four LED lighting treatments with different red, blue, green, ultraviolet-A, and far-red light ratios, and a treatment in greenhouse as low-light control were used. The constant 16 h photoperiod and light intensity of 220 µmol·m⁻²·s⁻¹ were maintained. The F2 treatment (UV-A:B:R:Fr = 6.60:45.15:29.23:19.02) promoted the greatest plant height (76.62 cm), and chlorophyll a (7.41 mg/100 g, FW), chlorophyll b (4.73 mg/100 g, FW), and total phenolic (25.78 mg/g, FW) concentrations. F1 treatment (B:G:R:Fr = 17.14:29.8:47.4:5.66) produced significantly higher (p < 0.01) biomass (8.3 ton/ha, FW), oil yield (10.89 L/ha), and carotenoid (3.74 mg/100 g, FW) than the others. Essential oils contained 12–15 compounds, dominated by neral (27.5–37.3%), geranial (41.1–49.9%), and (E)-β-caryophyllene (2.4–9.9%), while the highest contents of oil (0.83%, DW), anthocyanin (16.50 mg/100 g, FW), and total flavonoid (14.17 mg/g, FW) were obtained under F4 (B:G:R:Fr = 13.85:43.50:39.30:3.35). These findings demonstrate that optimized LED spectra can effectively improve both productivity and phytochemical quality in O. africanum through regulating both primary and secondary metabolism. Full article

TiO₂–biochar-based photocatalysts are one of the materials exhibiting adsorption-photocatalytic synergy. They have been widely used in the remediation of water systems. Current reviews in this field predominantly focus on the following aspects. These include the preparation methods for composite materials, the pollutant removal performance, the adsorption–photocatalytic synergy, and environmental applications. However, there are still gaps in understanding the intrinsic relationships among photocatalyst morphology, surface functional groups, reactive oxygen species (ROS) generation, pollutant removal, and interfacial charge-transfer mechanisms. This restricts the potential for further enhancement of photocatalytic performance. To fill this gap, this review provides a comprehensive summary of the impact of various parameters on the morphology of TiO_2–biochar-based photocatalysts during in situ synthesis. These factors include titanium sources, carbon sources, preparation methods, solvents, pyrolysis conditions, and doping modifications. Further analysis is conducted to investigate the effects of morphological structure on the distribution characteristics of surface functional groups (e.g., oxygen- and nitrogen- containing groups), the generation of ROS, and the removal behavior of organic pollutants. Furthermore, this review focuses on the effects of three typical morphologies. The three typical morphologies include surface-adhered, pore-embedded, and interlayer-distributed. The role of morphology in charge transport behavior at interfaces is also examined. We systematically elucidate the mechanisms of coupled interactions among material morphology, surface functional groups, ROS, interfacial charge transport, and photocatalytic performance. An analytical framework is established to explore the relationships among morphology control, structural characteristics, and photocatalytic performance. Lastly, the limitations of TiO₂–biochar-based photocatalysts in environmental remediation processes are summarized. It also points the way forward for future development. Overall, this review provides a new theoretical perspective on the rational design and environmental applications of high-performance TiO_2–biochar-based photocatalysts. Full article

Green synthesis of zinc oxide nanoparticles (ZnO NPs) represents a sustainable alternative to conventional chemical synthesis by employing biocatalytic systems under environmentally benign conditions. This study presents a systematic modeling approach based on Design of Experiments (DoEs) to optimize the green synthesis of ZnO nanoparticles intended for water treatment applications. Fractional factorial design was first applied to identify the most influential synthesis parameters, including precursor concentration, bio-reductant ratio, pH, temperature, and reaction time. Subsequently, response surface methodology using a D-optimal experimental design was employed to establish predictive mathematical models describing the relationships between process variables and nanoparticle size. The developed models enabled identification of optimal synthesis conditions and prediction of parameter combinations required to produce nanoparticles with targeted dimensions suitable for enhanced photocatalytic activity, antimicrobial performance, and colloidal stability. The proposed data-driven optimization strategy provides a robust, reproducible, and scalable protocol for green ZnO nanoparticle synthesis while minimizing reagent consumption and environmental impact. These findings contribute to the development of sustainable nanomaterials as the first step toward the future application of these ZnO nanoparticles as sustainable photocatalysts for water treatment. Full article

To meet national and global air quality and climate ceilings, it is essential to provide farm-level decision support tools for mitigating gaseous emissions from agriculture. A major challenge is to develop reliable tools that can be adapted to country-specific conditions, particularly in countries where such tools are currently lacking, and support farmers in assessing emission mitigation measures. To address this challenge, a Prototype Decision Support Tool (PDST) for estimating and mitigating gaseous emissions at the livestock farm scale was developed based on the FarmAC whole-farm model. The PDST supports livestock farm-level assessment of carbon emissions, including CH₄ and CO₂, and nitrogen-related emissions, including N₂O and NH₃. Emissions were estimated using the IPCC 2006 Guidelines, their 2019 Refinement, and the EMEP/EEA 2023 methodology. The PDST was applied to two intensive pig farms in Greece, both with fully slatted housing and outdoor slurry tank storage, and two intensive dairy cattle farms, one in Greece and one in Poland, both using deep-litter housing with solid manure storage. For these farms, the PDST estimated total annual emissions of 1.58 and 1.54 kg CO₂eq per kg of pig live weight and 0.80 and 0.66 kg CO₂-eq per kg of raw milk, respectively. These estimates were consistent with values reported in the literature for comparable production systems and emission sources, supporting the preliminary consistency of the PDST outputs. The PDST can form the software basis to support stakeholders in choosing farm-level practices that specifically reduce emissions. Full article