Search Results (13,827)

Understanding and controlling thermal rectification is pivotal for designing phononic devices that guide heat flow in a preferential direction. This study investigates one-dimensional atomic chains with binary mass asymmetry and nonlinear interatomic potentials, focusing on how energy propagates under thermal and wave excitation. Two potential models—the β-FPU and Morse potentials—were employed to examine the role of nonlinearity and bond softness in energy transport. Simulations reveal strong directional energy transport governed by the interplay of mass distribution, nonlinearity, and excitation type. In FPU chains, pronounced rectification occurs: under “cold-heavy” conditions, energy in the left segment increases from ~1% to over 63%, while reverse (“hot-heavy”) cases show less than 4% net transfer. For wave-driven excitation, the rectification coefficient reaches ~0.58 at 100:1. In contrast, Morse-based systems exhibit weaker rectification (∆E < 1%) and structural instabilities at high asymmetry due to bond breaking. A comprehensive summary and heatmap visualization highlight how system parameters govern rectification efficiency. These findings provide mechanistic insights into nonreciprocal energy transport in nonlinear lattices and offer design principles for nanoscale thermal management strategies based on controlled asymmetry and potential engineering. Full article

Micro-computed tomography ($\mu$CT) and X-ray Fluorescence (XRF) were used to investigate a Polymetallic Nodule (PN) from the North-Western Pacific abyssal plain to gather more information concerning the environmental changes that could be reflected by the PN’s internal structure. Despite its small size, for example, an ovoid measured 48 × 38 mm, the $\mu$CT revealed the presence of four concentric layers with varying thicknesses and opacities to X-rays, all developed around a fragment of a tooth, most likely belonging to a Lamniformes shark. The same micro-tomograph, functioning as an XRF spectrometer, allowed for the determination of the mass fractions of Mn and Fe in the first two external layers. To estimate the PN age, a model that considers PN growth rate proportional to the ratio of Mn to the square of Fe mass fractions was used, and, by extrapolating it to the entire PN, its age was estimated at 1.56 ± 0.22 Ma, i.e., Early Pleistocene. Therefore, the correlated use of $\mu$CT and FRX, two noninvasive methods, allowed to highlight a shark tooth fragment as being the PN nucleus as well as determine its absolute age. Full article

The synthesis, reaction process, and mechanical properties of medium-entropy (TiVNb)₂AlC MAX phase materials were investigated. The Ti, V, Nb, Al, and C powders were mixed and sintered by the powder metallurgy method. The experimental results showed that the highest purity M₂AlC phase with a mass fraction of 95.8% was obtained when the raw material ratio was M(Ti:V:Nb):Al:C = 2:1.2:0.7 and the sintering temperature was 1450 °C. In order to explore the sintering process reactions and optimize the purity of sintered products, sintering was carried out under different temperatures and various molar ratios of raw materials. During the sintering process, the metal elements firstly reacted with aluminum to generate intermetallic compounds (IMCs), and with the increase in temperature, the IMCs gradually reacted with carbon to generate M₂AlC. Mechanical property tests revealed that the Vickers hardness of the medium-entropy (TiVNb)₂AlC material was 6.52 GPa, significantly higher than both the theoretical prediction based on the rule of mixtures and the hardness of traditional MAX phases. The severe lattice distortions in the polymeric solid solution structure contributed to this significant increase in hardness. In addition, the medium-entropy (TiVNb)₂AlC exhibited temperature-dependent friction behavior within the temperature range of room temperature to 400 °C, with the lowest friction coefficient observed at 200 °C when the sample was in contact with the bearing steel. This study provided an important theoretical and experimental basis for the synthesis and future application of medium-entropy MAX phase materials. Full article

In this study, the presence of seven polychlorinated biphenyl (PCB) congeners proposed by ICES-7 (International Council for the Exploration of the Sea) (PCBs 28, 52, 101, 118, 138, 153, and 180) in milk, dairy products, and beverages was investigated, and potential risks to consumer health were assessed. A total of 130 samples were analyzed using gas chromatography–mass spectrometry (GC–MS/MS). Most PCBs levels were below the limits of detection and quantification, but trace amounts, particularly of PCB 153 and PCB 180, were detected. Overall, 35% of milk and dairy products and 20% of beverage samples exceeded the reference limits for ICES-7, with higher accumulation observed in high-fat dairy products. Packaging type also appeared to influence contamination levels. The study findings indicate that PCBs contamination levels may vary depending on product type, content, production method, and packaging structure. Three consumption scenarios were modeled for children and adults, and the estimated daily intake (EDI) was calculated. All hazard index (HI) values found to be below 1. This result suggests no significant non-carcinogenic health concern across the examined products and packaging types. Nevertheless, given the persistence and bioaccumulation potential of PCBs, continuous monitoring remains essential. Full article

Naproxen (NPX), a nonsteroidal anti-inflammatory drug, is considered an emerging contaminant due to its persistence and potential environmental risks. In this study, NPX degradation was investigated through ozonation using nickel–iron foam (NiFeF) and NiO-modified NiFeF (NiO/NiFeF). The effect of the foam size was investigated using three configurations: S1 (1 cm × 2.5 cm), S2 (2 cm × 2.5 cm), and S3 (2 cm × 5 cm). Complete NPX removal was achieved in all systems, with degradation times of 4 min for ozonation alone, 2 min for NiFeF-S1, and 1 min for NiO/NiFeF-S2 and NiO/NiFeF-S3. The NiO/NiFeF catalyst was synthesized via ultrasonic spray pyrolysis, resulting in a porous structure with abundant active sites. Compared with conventional ozonation, NiO/NiFeF-S1 improved the total organic carbon (TOC) removal rate by 6.2-fold and maintained 87.5% of its activity after five reuse cycles, demonstrating excellent stability. High-resolution mass spectrometry revealed that catalytic ozonation generated fewer by-products (22 vs. 27 for ozonation alone) and promoted more selective pathways, including demethylation, ring-opening oxidation, and partial mineralization to CO₂ and H₂O. This enhanced performance is attributed to the synergy between NiO and NiFeF, which facilitates reactive oxygen species generation and electron transfer. These results demonstrate the potential of NiO/NiFeF as an efficient and stable catalyst for pharmaceutical removal from water. Full article

Lithium slag (LS), a solid waste generated during lithium smelting, exhibits significant potential for geopolymer preparation. However, the high shrinkage of lithium slag geopolymer mortar (LSGM) severely restricts its engineering application. Currently, research on the effects of mix proportions (GBFS-LS mass ratio, water–binder ratio, and binder–sand ratio) on LSGM’s shrinkage, and the correlation between shrinkage behavior and microstructures (pore structure and thermal behavior), remains insufficient. Additionally, there is a lack of targeted shrinkage prediction models for LSGM. To address these research gaps, this study systematically investigates the shrinkage characteristics of LSGM and develops a modified prediction model. Thermogravimetric analysis–differential thermal gravimetric analysis (TG-DTG) results show that a lower GBFS-LS ratio promotes the formation of dense sodium-alumino-silicate hydrate (N-A-S-H) gels. Meanwhile, mercury intrusion porosimetry (MIP) tests demonstrate that optimizing the water–binder ratio and binder–sand ratio refines the pore structure of LSGM, where the average pore size is reduced from 53.5 nm at a GBFS-LS ratio of 3 to 28.75 nm at a GBFS-LS ratio of 1.5.Quantitatively; compared with the group with a GBFS-LS ratio of 3, the 90-day shrinkage strain of the group with a GBFS-LS ratio of 1.5 decreases by 25.8%. When the water–binder ratio decreases from 0.57 to 0.27, the 90-day shrinkage strain reduces by 36.7%; in contrast, increasing the binder–sand ratio from 0.21 to 0.39 leads to a 39.8% increase in 90-day shrinkage strain. Based on the experimental data and the fundamental framework of the American Concrete Institute (ACI) model, this study introduces mix proportion influence coefficients and constructs a novel shrinkage prediction model tailored to LSGM. The coefficient of determination (R²) of the proposed model exceeds 0.98. This model provides a reliable quantitative tool for the mix proportion optimization and engineering application of LSGM. Full article

This study proposes a new approach to identify structural parameters under seismic excitation using classical and quantum-inspired algorithms. Traditional methods often struggle with complex effects, noise, and computing limits. A five-story building model with mass–spring–damper system was tested to find properties during earthquakes. The study used optimization methods including Genetic Algorithm (GA), Particle Swarm Optimization (PSO), and five quantum-inspired versions: Quantum Genetic Algorithm (QGA), Quantum Particle Swarm Optimization (QPSO), Quantum Non-Dominated Sorting Genetic Algorithm II (QNSGA-II), Quantum Differential Evolution (QDE), and Quantum Simulated Annealing (QSA). Additionally, statistical analysis used Shapiro–Wilk for normality, Levene and Bartlett for variance, ANOVA with Tukey–Bonferroni comparisons, Bootstrap model ranking, and Borda count. The results show that the quantum-inspired methods perform better than classical ones. QSA reduced mean squared error (MSE) by 15.3% compared to GA, and QNSGA-II reduced MSE by 8.6% and root mean squared error (RMSE) by 3.5%, with less variation and tighter rankings. The framework addresses computing cost and response time; quantum methods need significant computing power and their accuracy suits offline earthquake assessments and model updates. This balance helps monitor building health when real-time speed is less critical but accuracy matters. The method provides a scalable tool for checking civil structures and could enable digital twins. Full article

This article focuses on the utilization of the supramolecular self-assembly of renewable materials derivatives to obtain functional compounds. Novel bio-based amphiphile molecules (CALAH and PALAH) were synthesized through a tailored process, involving Williamson ether synthesis and amidation reactions, employing renewable amino acid and cashew nut shell liquid (CNSL) derivatives as essential reactants. Their molecular structures were confirmed by nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HRMS), and Fourier-transform infrared spectroscopy (FT-IR). Notably, these compounds self-assemble into nanofibers that organize into a fibrous network, unexpectedly exhibiting two distinct morphologies: curved and rigid nanostructures. These structures were characterized by scanning electron microscopy (SEM), and their formation mechanisms were elucidated through temperature-dependent NMR studies and density functional theory (DFT) calculations. The sodium salts of the compounds (PALA and CALA) exhibited fundamental surfactant properties, exhibiting a hydrophilic lipophilic balance (HLB) value of 13.7 and critical micelle concentration (CMC) values of 1.05 × 10⁻⁵ M and 4.10 × 10⁻⁶ M. They also demonstrated low cytotoxicity, suggesting potential suitability in consumer applications. Furthermore, the compounds exhibited multi-functional performance as effective inhibitors of Staphylococcus aureus and efficient adsorbents for gaseous pollutants. Full article

Asteroids are remnants of primordial material from the early stages of solar system formation, approximately 4.6 billion years ago, and they preserve invaluable records of the processes underlying planetary evolution. Investigating asteroids provides critical insights into the mechanisms of planetary development and the potential origins of life. To enable efficient sample acquisition under vacuum and microgravity conditions, this study introduces a two-stage gas-driven asteroid sampling strategy. This approach mitigates the challenges posed by low-gravity environments and irregular asteroid topography. A coupled computational fluid dynamics–discrete element method (CFD–DEM) framework was employed to simulate the gas–solid two-phase flow during the sampling process. First, a model of the first-stage gas-driven sampling device was developed to establish the relationship between the inlet angle of the gas nozzle and the sampling efficiency, leading to the optimization of the nozzle’s structural parameters. Subsequently, a model of the integrated two-stage gas-driven sampling and sample-delivery system was constructed, through which the influence of the second-stage nozzle inlet angle on the total collected sample mass was investigated, and its design parameters were further refined. Simulation outcomes were validated against experimental data, confirming the reliability of the CFD–DEM coupling approach for predicting gas–solid two-phase interactions. The results demonstrate the feasibility of collecting asteroid regolith with the proposed two-stage gas-driven sampling and delivery system, thereby providing a practical pathway for extraterrestrial material acquisition. Full article

Stress granules (SGs) are dynamic membrane-less structures assembled in response to stress. The formation of stress granules in plants is poorly understood, especially the mechanism of mRNA recruitment. The problem of the specificity of mRNA interaction with stress granule proteins is unexplored. Oligouridylate binding protein 1B (UBP1B) is considered as the core element of plant SGs. In this study, we expressed the AtUBP1b protein from Arabidopsis thaliana in E. coli cells. Mass spectroscopic analysis showed that the AtUBP1b protein expressed in E. coli cells is phosphorylated at serine, threonine, and tyrosine residues. We also performed a de novo phosphorylation reaction in wheat germ extracts with the addition of radioactively labeled phosphorus and showed AtUBP1b phosphorylation in plant extracts. We hypothesized that phosphorylation or dephosphorylation of AtUBP1b in plant cells is a signal for protein binding to RNA. The purified protein was tested for its ability to bind to mRNA in vitro. In gel-shifting assays we demonstrated that AtUBP1b protein binds specifically to 5′-untranslated regions (5′UTR) of mRNA. When AtUBP1b was added to a cell-free wheat germ translation system, it exerted different effects on protein synthesis. We showed that AtUBP1b had a significant inhibitory effect on the expression of mRNAs containing 5′UTRs that were shown to bind to the protein in the gel-shifting reaction. Full article

This paper presents the development and evaluation of an autonomous solar dryer designed to enhance the drying efficiency of bee bread granules. In contrast to natural open-air drying, the proposed system utilizes solar energy in an oscillating operational mode to achieve a controlled and accelerated drying process. The dryer comprises a solar collector integrated into the base of the drying chamber, which facilitates convective heating of the drying agent (air). The system is further equipped with a photovoltaic panel to generate electricity for powering and controlling the operation of air extraction fans. The methodology combines numerical modeling with experimental studies, structured by an experimental design framework. The modeling component simulates variations in temperature (288–315 K) and relative humidity within a layer of bee bread granules subjected to a convective air flow. The numerical simulation enabled the determination of the following: the time required to achieve a stationary operating mode in the dryer chamber (20 min); and the rate of change in moisture content within the granule layer during conventional drying (18 h) and solar drying treatment (6 h). The experimental investigations focused on determining the effects of granule mass, air flow rate, and drying time on the moisture content and temperature of the granular layer of Bee Bread. A statistically grounded analysis, based on the design of experiments (DoE), demonstrated a reduction in moisture content from an initial 16.2–18.26% to a final 11.1–12.1% under optimized conditions. Linear regression models were developed to describe the dependencies for both natural and forced convection drying. A comparative evaluation using enthalpy–humidity (I-d) diagrams revealed a notable improvement in the drying efficiency of the proposed method compared to natural drying. This enhanced performance is attributed to the system’s intermittent operational mode and its ability to actively remove moist air. The results confirm the potential of the developed system for sustainable and energy-efficient drying of bee bread granules in remote areas with limited access to a conventional power grid. Full article

This study analyzes winds over the Red Sea (17 N, 39.5 E) and consequences for the northeast African climate in early summer (May–July). As the Indian SW monsoon commences, NNW winds > 6 m/s are channeled over the Red Sea between 2000 m highlands, forming a low-level jet. Although sea surface temperatures of 30C instill evaporation of 8 mm/day and surface humidity of 20 g/kg, the air mass above the marine layer is dry and dusty (6 g/kg, 100 µg/m³). Land–sea temperature gradients drive afternoon sea breezes and orographic rainfall (~4 mm/day) that accumulate soil moisture in support of short-cycle crops such as teff. Statistical analyses of satellite and reanalysis datasets are employed to reveal the mesoscale structure and temporal response of NE African climate to marine winds via air chemistry data alongside the meteorological elements. The annual cycle of dewpoint temperature often declines from 12C to 4C during the Indian SW monsoon onset, followed by dusty NNW winds over the Red Sea. Consequences of a 14 m/s wind surge in June 2015 are documented via analysis of satellite and meteorological products. Moist convection was stunted, according to Cloudsat reflectivity, creating a dry-east/moist-west gradient over NE Africa (13–14.5 N, 38.5–40 E). Diurnal cycles are studied via hourly data and reveal little change for advected dust and moisture but large amplitude for local heat fluxes. Inter-annual fluctuations of early summer rainfall depend on airflows from the Red Sea in response to regional gradients in air pressure and temperature and the SW monsoon over the Arabian Sea. Lag correlation suggests that stronger NNW winds herald the onset of Pacific El Nino. Full article

Diols represent a structurally diverse class of compounds with considerable biological and functional significance. Herein, we describe the synthesis of 1,1-bis(4-ethylphenyl)propan-1,2-diol (BEPP) via a Grignard reaction. The structure of BEPP was unambiguously elucidated by ¹H and ¹³C nuclear magnetic resonance (NMR), heteronuclear multiple-bond correlation (HMBC), high-resolution mass spectrometry (HRMS), and infrared (IR) spectroscopy. Full article

Addressing the core issue of rock mass failure and deformation induced by local water-induced uneven expansion in expansive soft rock tunnels, this study systematically analyzes the stress–displacement response of the rock mass under various working conditions. This analysis integrates physical model testing with FLAC3D 6.0 numerical simulation and covers four typical expansion zone configurations (vault, spandrel, haunch, invert) as well as multiple stages of stress loading. Leveraging the mathematical analogy between heat conduction and fluid seepage and combining it with a thermo-hydraulic coupling approach, the FLAC3D temperature field module precisely simulates the moisture-induced stress field. This overcomes the limitations of traditional tools for direct moisture field simulation and enables quantitative assessment of how localized expansion impacts tunnel lining failure. The study reveals that horizontal expansion zones significantly increase the risk of shear failure in tunnel structures. Expansion zones at the tunnel crown and base (invert) pose critical challenges to overall safety and exhibit a pronounced nonlinear relationship between stress loading and displacement. This research deepens the theoretical understanding of the interaction between localized non-uniform expansion and the surrounding rock mass and provides crucial technical guidance for optimizing tunnel support systems and improving disaster monitoring and prevention measures. Full article

Electrospun fibers serve as a medium for the targeted release of active compounds, facilitating the desired therapeutic effects in drug administration. The point of this study was to find the best conditions for making electrospun fibers from cellulose acetate (CA) and poly(ε-caprolactone) (PCL), mixed with pure oxyresveratrol extract from Artrocarpus lakoocha Roxberg (Moraceae). Additionally, the study focused on evaluating the antioxidant properties, antityrosinase activity, and freeze–thaw stability of the resulting fibers. We incorporated a concentration of oxyresveratrol at 0.1% w/w into various mass ratios of CA/PCL blended fiber sheets (1:0, 3:1, 1:1, 1:3), utilizing mixed solvents of acetone/DMF (2:1% v/v) and chloroform/DMF (9:1% v/v) for preparation. The fiber sheets displayed a continuous and uniform structure, with fiber diameters ranging from 300 to 1000 nanometers. We investigated the release kinetics of oxyresveratrol from the fibrous substrates using the total immersion technique, specifically in phosphate-buffered saline at a pH of 7.4. The results showed that the fiber sheet with a 3:1 w/w ratio of CA to PCL and a 0.1 w/w loading of oxyresveratrol showed the most significant release of oxyresveratrol at the 2 h mark, and it continued to release consistently at this peak value for up to 24 h. The antioxidant and anti-tyrosinase properties of oxyresveratrol in fiber sheets were more stable than those of free oxyresveratrol at the same concentrations. The fiber sheet presents a promising avenue for a user-friendly transdermal patch application. Full article