Search Results (4,802)

Stabilizing weak soils is a well-known pavement and geotechnical engineering technique. This technique involves introducing minimal cementitious materials to improve the soil’s geotechnical characteristics. This paper investigates the use of recycled industrial polymer waste (IPW) as a reinforcement material in the presence of cementitious binders to stabilize weak silty sand soil (SM), supporting sustainable engineering practices. The randomly distributed IPW were added as percentages of 0%, 5%, and 10% to a mixture of lime soil and cement soil, with varying amounts of 0% to 6% of lime (L) and 0% to 6% of ordinary Portland cement (OPC), respectively. The laboratory experiments were conducted on natural and stabilized samples in wet (unsoaked) and submerged (soaked) conditions. The experimental program included Proctor compaction, California bearing ratio (CBR), unconfined compressive strength (UCS), durability tests, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction analyses. The resilient modulus (Mr) was estimated using an empirical equation. The outcomes of this experimental study show that adding a combination of IPW shreds with a small amount of L and/or OPC to the SM soil provides a significant increase in the UCS, CBR, durability and Mr values compared with case of SM with only L, which allows for superior characteristics and increases strength and stiffness parameters throughout any phase of earthwork construction design, resulting in stronger and stiffer subgrades. These results were reinforced by microstructural observations from SEM, EDS, and DRX, confirming the formation of cementitious gels and chemical compounds, consistent with the macro-scale mechanical improvements. The expected practical outcomes include potential reductions in pavement thickness, which can help lower pavement stabilization costs and extend its service life. Additionally, the use of waste materials to replace raw materials contributes to decreased energy consumption and emissions, although detailed assessments are needed to quantify these effects. Full article

The increasing prevalence of drug-resistant microorganisms has prompted research into novel antimicrobial compounds, with 2-thiophene carboxylic acid thiourea derivatives showing promise for future therapeutic applications. However, the poor water solubility of these compounds limits their practical use. This study investigates the formation and characterization of inclusion complexes between 2-hydroxypropyl-β-cyclodextrin (HPβCD) and 2-thiophene carboxylic acid-halogenated (chlorine-, bromine-, and iodine-) thiourea derivatives, seeking to improve their physicochemical properties. The dynamic light scattering (DLS) measurements and UV-Vis spectroscopy provided information related to thiourea–HPβCD aggregates and stoichiometry. Solid-state inclusion compounds and physical mixtures were prepared in two different molar ratios (thioureas:HPβCD = 1:1 and 1:2), and the morphology of the resulting powders was observed by scanning electron microscopy (SEM). Thermogravimetry (TG) and differential scanning calorimetry (DSC) (TG-DSC) coupled analysis were used to analyze thermal profiles in the temperature range of 25 °C to 600 °C, while the spectral data obtained by Fourier transform infrared spectroscopy (FTIR) provided the characteristic vibrational bands of the pure guest molecules and data corresponding to the structural and chemical changes in the host–guest systems. The structural and thermal analyses revealed significant interactions between the host and thioureas molecules, with evidence of possible interactions involving two cyclodextrin molecules. The results demonstrate the presence of intermediate stoichiometry in the inclusion compounds, with possible enhancement of the therapeutic potential of these thiourea derivatives. Full article

In this paper, we present the result of the study conducted on aging tests carried out by the artist Emile Claus (1849–1924), composed of oil paint samples from three manufacturers: Blockx, Lefranc Bourgeois and Fritz Behrendt. These colors were applied neat and mixed with white on wooden panels prepared with white ground layer. A non-invasive analytical protocol, combining imaging techniques and physico-chemical analyses, was used to characterize potential differences between manufacturers for nominally identical colors. The differences highlight in this study include variations in nickel content in cobalt blue colors and aluminum content in madder lakes. It also discusses the intrinsic and extrinsic factors that led to the degradation of certain colors. Hyperspectral imaging further demonstrated that the addition of lead white induces a systematic shift of spectral inflection points toward shorter wavelengths, consistent with the optical dilution effect in pigment-white mixtures, while the altered colors do not follow the same trend. Full article

Polychlorinated biphenyls (PCBs) persist in the environment as complex mixtures and undergo extensive biotransformation, yet the developmental toxicity of PCB metabolites remains poorly defined. We evaluated developmental, neurobehavioral, and molecular effects of parent PCBs, hydroxylated, methoxylated, and sulfated metabolites, and environmentally relevant mixtures using embryonic zebrafish. This study employed a high-throughput screening approach using nominal exposure concentrations to enable rapid hazard identification and prioritization across a large chemical series. Morphological abnormalities and photomotor behavior were assessed across early development, followed by targeted cyp1a reporter analysis and transcriptomic profiling for a subset of potent exposures. Most chemicals induced morphological effects, with hydroxylated and sulfated metabolites producing effects more frequently and at lower benchmark concentrations than parent congeners. Behavioral alterations were more prevalent in embryonic photomotor response than larval photomotor response and generally co-occurred with morphological effects. Environmental mixtures elicited broad phenotypic profiles comparable to highly active individual compounds. Transcriptomic analyses revealed minimal responses for parent PCBs but robust, exposure-specific gene expression changes for select metabolites, particularly 5-OH-PCB11, and mixtures. Differentially expressed genes were enriched for xenobiotic metabolism, immune signaling, and neuroactive pathways, alongside consistent downregulation of circadian regulators. Together, these results demonstrate contributions of PCB metabolites and mixtures to toxicity. Full article

Brominated flame retardants (BFRs) are widely used in automotive polymers and electronic components, yet vehicles remain an under-characterized and potentially high-exposure microenvironment, particularly in hot climates. This study provides the first comprehensive assessment of BFR occurrence, sources, and exposure risks in vehicle dust from Saudi Arabia, addressing a critical regional data gap. This study systematically investigates the occurrence, compositional patterns, sources, and human exposure risks of polybrominated diphenyl ethers (PBDEs) and selected alternative BFRs in dust from 80 vehicles (domestic cars and taxis; model years 2015–2022) operating in Jeddah, Saudi Arabia. Dust samples were collected using a standardized vacuuming protocol, extracted and cleaned using solvent extraction and silica SPE, and analyzed via GC–NCI–MS. Both legacy PBDE congeners and emerging alternatives (including DBDPE and TBB) were consistently detected, with BDE-209 dominating the overall BFR burden with mean concentrations of 6560 ng/g in domestic vehicles and 5454 ng/g in taxis, with maximum values reaching 220,860 ng/g. Lower-brominated PBDEs occurred at substantially lower concentrations, reflecting the ongoing global transition away from Penta- and Octa-BDE formulations. Taxis exhibited generally higher concentrations than domestic vehicles, likely due to prolonged occupancy, increased usage intensity, and enhanced dust resuspension dynamics. Multivariate analysis (PCA and correlation) revealed two distinct source categories: (i) legacy Penta-BDE-related congeners associated with polyurethane foam and textile materials and (ii) high-brominated PBDEs and DBDPE linked to hard plastics and electronic components. Human exposure assessment demonstrated that dust ingestion is the dominant exposure pathway, while dermal and inhalation routes contribute minimally. Non-carcinogenic hazard indices (HI) were well below unity for all compounds (HI < 1.67 × 10⁻⁶), and incremental lifetime cancer risks (ILCR) for BDE-209 remained within or near accepted risk thresholds (7.52 × 10⁻⁶–1.04 × 10⁻⁵), although occupational exposure among taxi drivers was consistently higher. Overall, the results demonstrate that modern vehicle cabins act as significant microenvironments for chronic BFR exposure, particularly under high-temperature conditions. Despite generally low estimated risks, the combined effects of chemical persistence, bioaccumulation potential, and mixture toxicity—amplified by extreme in-cabin temperatures—highlight vehicles as overlooked yet significant exposure environments. These findings provide the first comprehensive dataset for the Arabian Peninsula and emphasize the need for climate-sensitive exposure assessment, safer material design, and targeted mitigation strategies in vehicle interiors. Full article

This study investigates the separation performance of transformer oil–water mixtures using gravity separation and chemical demulsification. The synthetic emulsion had an initial oil concentration (C₀) of approximately 246,000 mg/L. For gravity separation, the effects of compartment volume ratio, influent flow rate, initial water level, and oil discharge strategy were systematically evaluated. Under optimal conditions (volume ratio 2:1:1, flow rate 0.0055 L/s, initial water level 5 cm), the effluent oil concentration was reduced to as low as 0.020 mg/L, corresponding to a removal efficiency higher than 99.99%. For chemical demulsification, polyaluminum chloride (PAC), polyferric sulfate (PFS), polyacrylamide (PAM), and an organosilicon polyether demulsifier (MCL-D) were tested. The effects of pH, dosage, and temperature on demulsification efficiency (DE) and dehydration rate (DR) were investigated. Under optimal conditions (pH 3–5, dosage 300 mg/L, temperature 50 °C), MCL-D achieved the best performance, with a DE of 95.09% and a DR of 99.50%. Overall, gravity separation is effective for removing free and dispersed oil with low operational cost, whereas chemical demulsification is more suitable for treating stable emulsified oil. The combination of these two methods provides an efficient strategy for the treatment of transformer oil-containing wastewater. Full article

Bark beetle–fungus associations are essential for nutrition, detoxification, and host colonisation, but their composition and function vary across developmental stages and environmental contexts. Hence, we characterised the fungal communities associated with two pine-feeding bark beetles, Ips sexdentatus (ISX) and Ips acuminatus (IAC), across developmental stages and compared wild-collected and laboratory-bred populations using ITS2 amplicon sequencing. Both beetle species maintained a stable core mycobiome dominated by Kuraishia, Ogataea, Ophiostoma, Graphilbum, and Cyberlindnera. These taxa have been earlier reported to be associated with nutrient provisioning, detoxification of host secondary metabolites, and chemical signalling. Adult beetles showed species-specific community differences, whereas wild-collected beetles, particularly IAC, harboured higher fungal diversity than laboratory populations, indicating a strong environmental effect. Beetles shared more fungal taxa with control wood than with gallery wood, suggesting possible fungal acquisition during feeding and concurrent restructuring of the wood mycobiome during infestation. Monoterpene bioassays with selected yeast symbionts showed differential growth responses to α-pinene, 3-carene, and terpinolene, and their mixture, with the mixture producing stronger inhibition than individual compounds. These yeast symbionts further displayed selective antagonistic activity in vitro against selected filamentous fungi, including entomopathogenic taxa, along with detectable lytic and digestive enzyme activities. Together, our findings highlight a link between community structure, predicted functions, and observed interaction phenotypes, providing a strong basis for future mechanistic studies of beetle–fungus–conifer interactions. Full article

This study investigates the effect of the gas mixture composition ratio (Ar:N₂:O₂) during magnetron sputtering on the morphology, phase composition, and visual characteristics of TiN_xO_y thin films. Five different modes were used with a variable N₂:O₂ ratio ranging from 0.5 to 3. The resulting coatings exhibited noticeable differences in color—from golden to dark blue—which correlates with changes in chemical composition and phase state. The morphology of the films, examined by scanning electron microscopy (SEM), varied from a dense to a columnar structure. These results demonstrate that the properties of TiON coatings can be controlled by adjusting the N₂:O₂ ratio: nitrogen-rich conditions promote denser coatings with higher hardness and improved wear resistance, whereas a balanced N₂:O₂ ratio enhances coating adhesion to the substrate. Full article

Pistacia lentiscus L. var. Chia is an endemic tree cultivated in the Southern part of Chios Greek Island. Chios mastiha, the aromatic resin secreted from this tree, has been used as traditional remedy since ancient times to cure many peptic system diseases and as a nutritional agent. Nowadays, Chios mastiha has been widely investigated for its biological activities and its chemical composition. A major part of Chios mastiha’s bioactive compounds are triterpenoids, which are proposed to interfere with glucocorticoid receptor (GR) signaling, acting as selective GR agonists. In this study a specific “neutral fraction” of Chios mastiha resin, a portion devoid of acidic triterpenoids, was investigated regarding its biological potential and chemical composition. The study aimed to determine if the neutral triterpenoids, the non-carboxylic ones, within this fraction drive Chios mastiha’s interference with GR signaling and whether it exhibits anti-inflammatory, apoptotic, and potential antilipidemic activities. The phytochemical characterization of this specific resin portion, applying ¹H NMR and HPLC-QTOF-MS/MS analysis, identified novel unidentified Chios mastiha’s phenolic components (apigenin, astragalin, diosmetin, flavidin, genistein), a complex mixture of fatty acids (palmitic, stearic, oleic), non-carboxylic triterpenoids (lupeol, β-amyrin, keto-oleanolic aldehyde), and a trace of terpenoids. Biological assessment of DEX-induced GR transcriptional activation revealed that neutral triterpenoid fractions only minimally contribute to GR transcriptional activation while positively regulating GR and its target, phosphoenolpyruvate carboxykinase (PEPCK), protein levels. Additionally, negative regulation of the peroxisome proliferator-activated receptor alpha (PPARα) protein levels as well as inhibition of the TNFα-induced NF-κΒ activity and reduction in the p65 subunit of NF-κΒ protein levels, were observed, indicating potential antilipidemic and anti-inflammatory Chios mastiha’s neutral fraction activities, which were attributed to its composition in triterpenoids, fatty acids, and novel phenolic compounds. Moreover, mitochondrial-dependent induction of apoptosis accompanied by reduction in cell viability was observed in lupeol, β-amyrin, and fatty acids-enriched fractions. The plethora of bioactive compounds associated with a variety of Chios mastiha’s neutral fraction render Chios mastiha a valuable food additive and nutritional agent. Full article

Only recently, observational studies have started providing measurements for the barium isotopic ratio in metal-poor stars with unprecedented detail. This new approach can be extremely useful in tracing back the origin of neutron-capture elements, since the r- and s-process produce different amounts of barium isotopes, and their astrophysical sites of production are still largely unconstrained. We employ here a stochastic chemical evolution model of the Galactic halo to compare observations to theoretical predictions. We find that in the earliest phases of evolution, both r- and s-process sites are required, with the model and observations agreeing well for Sr, Ba and Eu, possibly requiring a slightly larger s-process production for Sr. The model can actually explain the mixture of r- and s-process material often observed in halo stars. This work shows how is it possible now to use isotopic ratios in addition to elemental ratios to obtain additional constraints useful for the Galactic Archaeology investigation. Full article

Alfalfa (Medicago sativa), a globally important perennial forage legume, is widely cultivated in China, where effective weed management is essential for sustainable production. Chemical weed control, primarily relying on the herbicide imazethapyr, represents the most common strategy. Reliance on a single-herbicide program, however, may lead to inconsistent weed control under field conditions and may raise environmental concerns when higher application rates are used. To address this challenge, a two-year field study (2022–2023) was conducted to reduce herbicide inputs and identify new weed management options through tank mixtures. Initial screening identified imazethapyr, prometryn, imazapic, and 2,4-DB as safe and effective against broadleaf weeds. To broaden the control spectrum and reduce total herbicide use, haloxyfop-R-methyl was tank-mixed with each of the four broadleaf-active herbicides. The combinations haloxyfop-R-methyl + imazethapyr (36.5 + 56.3 g a.i. ha⁻¹) provided broad-spectrum weed control without compromising alfalfa performance and, importantly, reduced herbicide input at least by 25% of the recommended label dose. Additionally, the mixture of haloxyfop-R-methyl with 2,4-DB (36.5 + 506.3 g a.i. ha⁻¹) achieved effective, broad-spectrum weed control, increased alfalfa yield, and reduced total herbicide input at least by 25% of the recommended label dose. This mixture offers a useful option for diversifying weed management programs and reducing reliance on repeated imazethapyr applications. These tank mixtures represent sustainable and practical components of an integrated weed management system in alfalfa production. Full article

Given the increasing concern around greenhouse gas emissions and the decline in the availability of fossil fuels, there is increasing global demand to develop alternate fuels for maritime transportation that are sustainable and which have lower greenhouse gas emissions. Methanol is one such alternative fuel that has garnered considerable attention given its potential to be produced by more sustainable processes and its more favorable greenhouse gas emission profile in comparison with current fossil fuels. Understanding the physical and chemical properties of methanol under a range of conditions is essential for its development as a marine fuel. In this study, we seek to define physical and chemical properties of different methanol samples to simulate real-world storage conditions as these data are lacking in the literature. Several methanol samples were evaluated: nearly pure methanol; International Organization for Standardization (ISO) marine methanol (MM) grades A, B, and C; and methanol plus higher alcohols. We first evaluated all methanol samples for impurities, acetic acid content, density, and distillation range. We then characterized the effects of water absorption and found that methanol can easily absorb unacceptable water content from humid air within hours, necessitating storage conditions that prevent this process. In eight-week aging experiments at 20 °C and 40 °C in ambient air, we did not observe significant oxidation for any of the methanol samples; however, we did observe increases in acid number. We assessed the impact of contamination of methanol with water, marine gas oil (MGO), and an MGO–biodiesel mixture on density, viscosity, distillation range, and lubricity. Finally, we show that MGO contamination of methanol results in a slight increase in sooting tendency. In aggregate, our results provide an in-depth analysis of physical and chemical properties of methanol as well as the impacts of storage conditions and impurities on the properties of fuel methanol. Full article

Metal–organic frameworks (MOFs) show great potential for post-combustion carbon capture, yet their practical application is often constrained by challenges such as powder handling difficulties, limited structural stability during shaping processes, and performance degradation under high-humidity conditions. In this study, Mg-gallate was structured into millimeter-sized Mg-gallate/CA composite beads via the ionotropic gelation method, and then a hydrophobic layer of vinyltrimethoxysilane (VTMS) was constructed on the bead surface by chemical vapor deposition. The synthesized Mg-gallate/CA and V-Mg-gallate/CA are characterized by XRD, FT-IR, and other techniques, and their CO₂ adsorption behavior, adsorption–desorption kinetics, breakthrough performance, and cyclic stability are systematically evaluated. At 298 K and 0.1 bar, the CO₂ adsorption capacity of Mg-gallate/CA reached 94.2% of that of Mg-gallate powder. The microporous–microporous hierarchical structure constructed by the ionotropic gelation method improved the CO₂ capture efficiency of the composite beads by 16.7% at 0.1 bar. V-Mg-gallate/CA maintained a high dynamic CO₂ adsorption capacity of 2.87 mmol/g for a 10 vol.% CO₂/90 vol.% N₂ gas mixture at 298 K under 80% RH, corresponding to 2.04 times the capacity of Mg-gallate/CA, and retained 98.8% of its initial adsorption capacity at 0.1 bar after 10 cycles. Combining ionotropic gelation shaping with surface hydrophobic modification represents an effective strategy for developing MOF-based adsorbents suitable for post-combustion CO₂ capture. Full article

Current industry standards for evaluating concrete durability in wastewater environments, such as ASTM C267, rely almost exclusively on mass loss as the primary performance indicator. This study demonstrates that mass change alone can be an ambiguous metric that does not fully characterize the structural degradation of advanced cementitious binders. Through a comprehensive physical, chemical, and mechanical evaluation of 27 binary and ternary mixtures (totalling 486 specimens), we identify four limitations of mass-based standards: (1) The Slag Anomaly, where excellent surface mass preservation masks a significant loss of internal structural capacity, indicating potential internal structural softening. (2) The Sewage Anomaly, where specimens in active biogenic environments exhibit mass gain (up to +1.21%) despite continuous chemical attack. (3) Non-Linear Scaling, where 5% “accelerated” acid tests fundamentally alter degradation kinetics compared to realistic 1% environments. (4) The Maturation Conflict, where extended curing (56 days) significantly improves the physical resistance of slow-reacting pozzolans (cyment) while increasing the mass loss of high-performance ternary blends (MK/SF), likely linked to the exhaustion of their chemical buffering capacity. Current standards relying solely on mass loss may not capture internal degradation in slag-based cements that remain geometrically intact. We propose residual flexural strength as a necessary complementary metric. Full article

Chemical probe-based pattern analysis offers a powerful approach for evaluating complex mixtures, particularly in non-target sensing scenarios where components are unknown or where multivariate interactions, such as those involved in taste perception, dominate the response behavior. However, its broader applicability has been limited by challenges in generating sufficiently diverse probe sets and in acquiring multidimensional response data from large probe arrays. In this study, we address both limitations by constructing a high-capacity sensing platform that integrates artificial DNA-derived chemical probes with conventional fluorescent probes. Artificial DNA probes were synthesized following established modular assembly methods, enabling large-scale generation of structurally diverse sensing elements. An imaging-based detection instrument—combining controlled excitation and high-resolution fluorescence capture—was developed to simultaneously quantify color and intensity responses from up to 88 probes. We applied this system to the analysis of 20 taste-related compounds, demonstrating clear discrimination based on multidimensional fluorescence patterns. Furthermore, systematic evaluation of probe number versus classification accuracy revealed that increased probe diversity substantially enhances non-target discrimination performance, supporting the value of using low-specificity artificial DNA probes in high-density arrays. These results establish a versatile and scalable platform for non-target pattern analysis and highlight the importance of probe multiplicity in complex mixture sensing. Full article