Search Results (4,661)

This work provides a systematic experimental study for the electrochemical desalination of saline water using an electrospun permselective polyvinylidene difluoride (PVDF) membrane. Several nano additives were initially screened during membrane development; however, only the materials that demonstrated stable dispersion, reproducible membrane formation, and consistent electrochemical behaviour, namely graphene oxide (GO) and carbon nanotubes (CNTs) were selected for full analysis in this study. Accordingly, the study focuses on pure PVDF, PVDF/GO, and PVDF/CNTs membranes integrated with an alternating Ag/AgCl electrode system. The silver electrode is prepared by spray-coating of silver nanoparticles on high surface carbon cloth, whereas the AgCl electrode was prepared electrochemically from the Ag electrode using a three-electrode electrochemical cell. The electrochemical behaviour of various modified electrodes (bare carbon cloth, Ag/carbon cloth, Ag/nafion/carbon black/PVDF, and Ag/nafion/carbon cloth) was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and X-Ray Diffraction (XRD). The electrode prepared using Nafion and PVDF as binders with carbon black as conductive additive exhibited the highest current response and lowest charge-transfer resistance. When coupled with this optimized electrode, the PVDF/GO membrane delivered the best desalination performance, achieving an ion removal efficiency of 68%, a salt adsorption capacity (SAC) of 775.40 mg/g, and a specific energy consumption (SEC) of 16.17 kJ/mole values superior to those reported in the literature. Full article

Silica aerogels are critical for thermal protection in extreme environments; however, their mechanical response mechanisms under high temperatures remain elusive. This study employs large-scale molecular dynamics simulations to systematically investigate the mechanical behavior of silica aerogels (0.43–0.71 g/cm³) across a temperature range of 298–1800 K. The results reveal a fundamental competition between thermal softening and sintering-induced strengthening. Under tensile loading, the thermal softening effect dominates, leading to a significant fracture strength reduction of up to 49.6% at 1800 K, while simultaneously enhancing ductility, extending fracture strain to 80%. Conversely, under compressive loading, the sintering effect induced by temperatures above 900 K outweighs softening, resulting in a ~20% increase in the elastic modulus for high-density samples at 1300 K. Microstructural analysis attributes this enhancement to the preferential collapse of large pores and densification into an atomic-scale micropore range (0.5–1.0 nm). This work elucidates how the interplay between softening and sintering dictates material failure or strengthening, providing a microscopic theoretical basis for designing thermal shock-resistant materials for new energy batteries. Full article

Hydrophobic silica aerogels (SAs) have attracted much attention because of their excellent thermal insulation performance and have potential applications in energy conservation and emission reduction. However, the organic groups on its surface are flammable, which brings security risks and limits its application scope. In this study, two kinds of ammonium polyphosphate (APP) with different polymerization degrees, namely low-polymerization-degree APP (LAPP) and high-polymerization-degree APP (HAPP), were introduced into SA to prepare APP/SA composites, to improve the thermal safety of the materials. The results showed that APP with two polymerization degrees significantly delayed the initial decomposition and peak temperature of heat flow, and HAPP reduced the gross calorific value by 31.01% at most, which is 29.04% greater than that of LAPP, indicating that the effect of HAPP was slightly better than that of LAPP. With the increase in APP with two polymerization degrees, the density increased and the porosity decreased: LAPP system was 0.095–0.196 g/cm³ and 96.0–91.0%. Both made the thermal conductivity increase only slightly (up to 26.8 mW/m/K), but the sample still maintained excellent thermal insulation and hydrophobicity, which indicated that the addition of APP improved the thermal safety performance of SA while maintaining its basic excellent performance. This strategy provides an effective and simple way to improve the flame retardancy of SA, which makes SA more widely used in fields with strict requirements on thermal safety. Full article

Metal halides with efficient, stable, and tunable white light emission are ideal for lighting applications, because their emission properties can be effectively optimized through rational doping and precise compositional engineering. However, the synthesis of such materials often requires strict conditions and complex procedures. In this work, we report a phase transition from Sb-doped Cs₂InCl₅·H₂O to Cs₂NaInCl₆, along with tunable white light emission. Partial substitution of Na⁺ enables the formation of high-energy multiple emission centers, resulting in efficient white light with an adjustable correlated color temperature ranging from 2500 K to 5000 K under 365 nm excitation. The photoluminescence quantum yield reaches up to 45.24%. Efficient energy transfer among emission centers and the doping concentration of Na⁺ are critical for achieving high-performance tunable white light. The synthesized Cs₂Na_xInCl_5+x:Sb composite exhibits excellent stability under ultraviolet irradiation and environmental conditions such as oxygen and humidity, even after 200 h of ultraviolet irradiation, the emission spectrum remains stable, with more than 80% of its initial efficiency being preserved. Our results show its potential for advanced lighting applications and provide valuable insight for a desirable emission-tunable metal halide design. Full article

To meet the requirements of next-generation spacecraft thermal protection systems for lightweight materials with high strength, effective thermal insulation, and superior ablation resistance, a novel POSS-modified phenolic aerogel/quartz fiber composite (POSS-PR/QF) was developed using a thiol–ene click reaction combined with a sol–gel process. Covalent incorporation of polyhedral oligomeric silsesquioxanes (POSS) into the phenolic matrix effectively eliminates nanoparticle aggregation and improves interfacial compatibility. As a result, the modified resin is suitable for resin transfer molding (RTM) processes. The resulting composite exhibited an aerogel-like porous structure with enhanced crosslinking density, thermal stability, and oxidation resistance. At 7.5 wt% POSS loading, the composite achieved low density (~0.7 g·cm⁻³) and outstanding mechanical properties, with tensile, flexural, compressive, and interlaminar shear strengths increased by 114%, 79%, 29%, and 104%, respectively. Its thermal conductivity (0.0619 W/(m·K)) and ablation rates were also markedly reduced. Mechanistic studies revealed that POSS undergoes in situ ceramification to form SiO₂ and SiC phases, which create a dense protective barrier. In addition, this ceramification process promotes char graphitization, thereby enhancing oxidation resistance and thermal insulation. This work provides a promising approach for designing lightweight, high-performance, and multifunctional thermal protection materials for aerospace applications. Full article

Classroom acoustic conditions significantly affect students’ learning outcomes and teachers’ occupational health, yet a systematic gap persists between optimal acoustic standards established in research and their implementation in practice. Although peer-reviewed literature has defined performance thresholds, guidance on which design strategies effectively achieve these targets across different school spaces remains limited. Grey literature—project documentation from architectural firms, acoustic consultants, and material suppliers—contains valuable practice-based evidence. This study aimed to map practice-based evidence in K–12 school acoustic design, identify dominant space–strategy patterns, and appraise evidence quality through systematic mapping of grey literature. Following PRISMA-ScR guidelines, systematic searches were conducted across 27 websites representing three source types, yielding 142 projects from 22 countries. Data extraction employed a standardised coding framework encompassing project metadata, 19 space types, and 16 acoustic strategy subcategories within five major categories. Evidence quality was assessed using a quantified AACODS framework (score range 6–30), with inter-rater reliability (ICC = 0.989). The evidence landscape revealed geographic concentration in North America (41.5%) and the Asia–Pacific region (26.8%), with architectural firms contributing most documentation (54.2%). Space–strategy analysis identified dominant patterns: classrooms and corridors primarily employed absorptive ceilings combined with wall treatment, gymnasiums relied on suspended absorbers, and performance spaces used multi-strategy packages including variable acoustics systems. Open-plan learning spaces displayed high strategy diversity without consensus solutions. Mean quality score was 15.2/30 (SD = 3.0), with only 16.9% of projects reporting quantitative performance indicators. These findings reveal a substantial research-to-practice gap and provide an empirical basis for developing targeted acoustic design guidance for practitioners, informing policy, standards, and future research directions. Full article

The thermally efficient and lightweight TRC/CLCi composite panels for functional and smart building envelopes, funded by the iclimabuilt project (Grant Agreement no. 952886), offer innovative solutions to sustainably address common failure risks in facade systems. This work specifically emphasizes strategies for mitigating structural, thermal, and fire-related failures through targeted material selection, advanced design methodologies, and rigorous validation protocols. To effectively mitigate structural failures, high-pressure concrete (HPC) reinforced with carbon fibers is utilized, significantly enhancing tensile strength, reducing susceptibility to cracking, and improving overall durability. To counteract thermal bridging—a critical failure mode compromising energy efficiency and structural integrity—the panels employ specially designed glass-fiber reinforced pins connecting HPC outer layers through the cellular lightweight concrete (CLC) insulation core that has a density of around 70 kg/m³ and a thermal conductivity in the range 35 mW/m∙K comparable to those of expanded polystyrene and Rockwool. These connectors ensure effective load transfer and maintain optimal thermal performance. A central focus of the failure mitigation strategy is robust fire behavior. The developed panels undergo rigorous standardized fire tests, achieving an exceptional reaction to fire classification of A2. This outcome confirms that HPC layers maintain structural stability and integrity even under prolonged fire exposure, effectively preventing catastrophic failures and ensuring occupant safety. In conclusion, this work highlights explicit failure mitigation strategies—reinforced concrete materials for structural stability, specialized glass-fiber connectors to prevent thermal bridging, rigorous fire behavior protocols, and comprehensive thermal performance validation—to produce a facade system that is robust, energy-efficient, fire-safe, and sustainable for modern buildings. Full article

Rye (Secale cereale L.) is a small-grain cereal traditionally cultivated under low-input conditions, where locally adapted populations have contributed substantially to the maintenance of genetic diversity. Despite this importance, Greek rye germplasm has received limited attention at the molecular level. In the present study, 33 rye accessions, including gene bank landraces, locally cultivated populations and one commercial variety, were analyzed using inter-simple sequence repeat (ISSR), start codon-targeted (SCoT), and exon-based amplified polymorphism (EBAP) markers. All three marker systems generated high proportions of polymorphic loci and comparable estimates of expected heterozygosity, indicating considerable genetic variability within the studied material. Multivariate analyses revealed moderate population structuring and consistently identified a small number of genetically divergent accessions, most notably T-492, K-163, and K-166. No clear clustering according to geographical origin was detected, as in most cases of landraces or local populations. Taken together, the results provide a detailed molecular overview of Greek rye germplasm—which has never been performed before for Greek rye genetic material—and offer a useful basis for conservation priorities and future pre-breeding efforts. Full article

Polyester yarn bundle geogrids are widely used materials in flexible retaining structures due to their high toughness and high-strength mechanical properties. To investigate the mechanical characteristics and the interfacial mechanical properties of these geogrids, a series of pull-out tests were conducted under different pull-out rates and filling water contents. Based on the test results, a DEM-FDM coupled numerical model for pull-out behavior was established to analyze the pull-out deformation behavior of the geogrids. Combined with the theoretical analysis of the load-bearing characteristics of the geogrids, the reinforcement mechanism of polyester yarn bundle geogrids was revealed. The results show that there exists a critical pull-out rate of 1 mm/min that maximizes the pull-out resistance; the interface friction angle decreases with an increase in pull-out rate, while the interface cohesion shows an opposite trend. The filling water content presents a more significant weakening effect on the soil–geogrid interface strength under low stress, resulting in a strain-softening type of pull-out curve. Unlike fine-ribbed plastic geogrids, the sliding frictional resistance of polyester yarn bundle geogrids accounts for 80% of the total pull-out resistance during the pull-out process. The mechanical interlocking force, which arises from the bulges on the mid-section of transverse ribs and the downward bending of longitudinal rib edges, is subject to dynamic changes in the course of the pull-out process. The geogrid exhibits overall shear failure under low normal stress (${\sigma }_n<$ 200 kPa) and penetration shear failure under high normal stress (${\sigma }_n\ge$ 200 kPa). In practical engineering installation, polyester yarn bundle geogrids should be placed as parallel as possible to maximize the frictional resistance with filled soil and should take care of the geogrid joints for enhanced durability of the geogrids. Full article

As a prevalent integrated structure-insulation system, sandwich insulation wall panels have emerged as a critical structural configuration for zero- and nearly zero-energy green buildings, owing to their high construction efficiency and superior thermal insulation performance which directly aligns with the core goals of sustainability and sustainable energy utilization in the built environment. However, connectors penetrate the insulation layer and form systematic thermal bridges, which cause substantial heat loss and become a key bottleneck limiting further improvement in the overall thermal performance of wall systems. This study established three-dimensional numerical models of sandwich insulation wall panels with four typical connectors (fiber-reinforced polymers (FRPs), clamp-type stainless steel, plate-type stainless steel, and truss-type stainless steel) using Ansys Fluent 2021R1. The model reliability was verified by calibrated hot-box experiments, with relative errors between simulation and experimental results ranging from 2.1% to 16.1%. Systematic numerical simulations were then performed to investigate the effects of connector type, insulation material, climate zone, inner–outer temperature difference, connector quantity, and wall dimensions on the thermal bridge effect. The results indicated that FRP connectors caused the minimal heat flux increment (only 0.27%), followed by clamp-type stainless steel connectors (9.59%), while plate-type and truss-type stainless steel connectors led to significant increments (27.17% and 27.62%, respectively). The lower the heat transfer coefficient (K-value) of the wall was, the more prominent the connector-induced thermal bridge effect was. Within the typical temperature difference range, the heat flux increment of each connector remained stable, and polyurethane (PU) insulation exhibited a more significant inhibitory effect on thermal bridges than extruded polystyrene (XPS) under the same K-value. Linear fitting formulas for the relationship between wall K-value/temperature difference and the heat flux correction coefficient were derived, with high goodness-of-fit. The maximum impact of connectors on wall thermal performance did not exceed 30%. This study provides theoretical support and design references for the selection of connectors, material optimization, and thermal performance calculation of sandwich insulation wall panels, contributing to the promotion of energy-saving building envelope technologies. Full article

Plastic pyrolysis can not only effectively solve the environmental pollution caused by the large use of plastics products but also can produce valuable chemical products to alleviate the energy shortage problem. Firstly, this study designs a microwave pyrolysis device for polypropylene plastic based on a symmetrical circular waveguide slot radiation structure. The microwave energy is fed in through the bottom symmetrical circular waveguide port, transmitted to the slot array unit after passing through the horn amplification structure, and then uniformly radiated into the polypropylene plastic. Secondly, the finite element method is employed to conduct multi-physics field coupling calculations for the electromagnetic field, temperature field, chemical reaction field, mass transfer field of concentrated substances, and fluid field involved in the microwave pyrolysis process. Finally, to improve the efficiency of microwave pyrolysis, the wave-absorbing material SiC is introduced to investigate the effects of different doping methods and doping mass ratios m_SiC:m_PP on pyrolysis temperature distribution uniformity, pyrolysis gas yield (Y_G), energy consumption (Q), gas composition, and higher heating value (HHV). The results indicate that optimal pyrolysis performance is achieved when the microwave power is 1000 W, the pyrolysis time is 9.2 min, SiC is uniformly doped and the mass ratio is m_SiC:m_PP = 3:1. The COV of temperature is a mere 0.0004, the Y_G reaches 75.15 wt.%, and Q is 0.15 kWh, the HHV is up to 85.32 MJ/Nm³, and the percentages of C₃H₆ and CH₄ are relatively high at 72% and 11.4%. These findings confirm the designed microwave pyrolysis device can achieve uniform and high-efficiency pyrolysis capability for polypropylene plastic. Full article

Recent discoveries of fluorite–barite deposits in the Donghai–Linshu area in northern Jiangsu Province, China, underscore the region’s mineral potential, yet detailed geological investigations remain limited. In this study, we examined monzonite and quartz monzonite from drill cores in the Jiashan mining area using petrography, U–Pb zircon dating, zircon trace element geochemistry, whole-rock geochemistry, and zircon Lu–Hf isotopes. Laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) zircon U–Pb analyses were conducted to constrain the crystallization ages of the monzonite (127.06 ± 0.54 Ma and 126.83 ± 0.75 Ma) and quartz monzonite (127.2 ± 0.5 Ma and 128.59 ± 0.62 Ma) to the Early Cretaceous, marking a significant magmatic event. Many of the zircons contain inherited Neoproterozoic cores (718–760 Ma and 800–860 Ma), indicating the assimilation of deep crustal materials of this age. The monzonite is metaluminous, with moderate SiO₂ (61.61–62.41 wt.%), high alkalis (Na₂O + K₂O = 7.48–7.92 wt.%), and A/CNK = 0.72–0.91. The quartz monzonite has higher SiO₂ (66.26–68.18 wt.%) and alkalis (8.32–9.33 wt.%). Both rock types exhibit similar trace and rare earth element patterns: enrichment in large-ion lithophile and light rare earth elements, depletions in Nb, Ta, and Ti, no significant Zr-Hf depletion, and weak negative Eu anomalies (δEu ≈ 0.84–1.00). Their low Zr + Nb + Ce + Y contents, Ga/Al ratios, and TFeO/MgO ratios indicate that they have an I-type granite affinity. The Early Cretaceous zircons have highly negative ε_Hf(t) values (−33.7 to −23.5) and ancient two-stage model ages (2622–3247 Ma), which are consistent with derivation from Archean crust. The inherited Neoproterozoic zircons have younger Paleo–Mesoproterozoic T_DM2 ages. The evidence suggests that both intrusions were mainly generated by partial melting of ancient Archean basement, with minor mantle input. The magma generation was likely triggered by crustal anatexis induced by the underplating of mantle-derived magmas in an extensional tectonic regime, coeval with Early Cretaceous magmatism in the Sulu orogen. Full article

Basalt Fiber Reinforced Polymer (BFRP) bolts offer a high mechanical performance, yet their non-destructive evaluation in anchorage systems remains scarcely investigated. This work examines guided wave propagation in BFRP bolt anchorage structures through a combined experimental and numerical analysis. Optimal excitation within 35–100 kHz was determined experimentally, revealing 40 kHz as the most stable mode, with a pronounced bottom reflection and a peak-to-peak amplitude of 0.31 V. Numerical simulations explored the influence of anchorage medium properties, bolt characteristics, and de-bonding defect locations and lengths on dispersion, attenuation, velocity, radial energy distribution, and echo response. The results indicate that denser anchorage media reduce velocity and attenuation but enhance radial nonuniformity, whereas a higher elastic modulus decreases amplitude and increases attenuation; a larger Poisson’s ratio elevates both velocity and attenuation. For the bolt, a higher density lowers velocity and attenuation, while a greater modulus amplifies both; Poisson’s ratio exerts a minor positive effect. Defect echo time varies linearly with defect position, and increasing the defect length elevates velocity yet diminishes amplitude. These findings elucidate the interplay between material parameters, defect geometry, and guided wave behavior, offering a basis for the optimized non-destructive testing (NDT) of BFRP bolts and facilitating their deployment in engineering applications. Full article

Background and Objectives: Sternocleidomastoid (SCM) dysfunction is commonly implicated in several musculoskeletal conditions. Accordingly, shear-wave elastography has been used to characterize SCM stiffness in asymptomatic and clinical cohorts. However, the only reproducibility study available reported limited reliability, so clinical interpretations should be made with caution. Therefore, this study revisits key methodological aspects of that protocol to assess intra-examiner reliability and includes two examiners with different levels of expertise to evaluate inter-examiner reliability. Materials and Methods: A longitudinal observational study was conducted, recruiting twenty-five asymptomatic participants. Two examiners with different experience levels participated in this study after following structured training. For each side, images were obtained in immediate succession in the sequence experienced–novice–experienced–novice (with side order randomized), using an ROI spanning full muscle thickness, stabilizing approximately 10 s before freezing to record Young’s modulus and shear-wave speed. Results: Inter-examiner agreement was good–excellent: single-measurement ICCs were 0.77–0.86, improving to 0.79–0.87 when averaging two trials, which also reduced the standard error of measurement (SEM) and minimal detectable changes (MDCs). Between-examiner mean differences were small and nonsignificant (p ≥ 0.068). Intra-examiner reliability was excellent (ICC ≈ 0.93–0.94) with small absolute errors. Precision was high (SEM ~5–6 kPa; 0.22 m/s), and MDCs were ~15–16 kPa and ~0.60 m/s, with no trial-to-trial bias (all p ≥ 0.311). Conclusions: The revised protocol showed excellent intra-examiner repeatability and good–excellent inter-examiner reliability with minimal bias. Averaging two acquisitions improved precision, while a single operator optimized longitudinal stability. Full article

Rising global electricity demand and the expansion of distribution networks require a critical assessment of component-level greenhouse gas contributions. Distribution transformers, although indispensable, have significant life-cycle carbon impacts due to the use of materials, manufacturing, and in-service losses. This study conducts a life-cycle assessment of a single-phase, 75 kVA oil-immersed distribution transformer manufactured in Newfoundland, one of the provinces with the cleanest, hydro-dominated grids in Canada, and evaluates it over a 40-year lifespan. Using a cradle-to-use boundary, the analysis quantifies embodied emissions from raw material extraction, manufacturing, and transportation, alongside operational emissions derived from empirically measured no-load and load losses. All the data are collected directly during the manufacturing process, ensuring high analytical fidelity. The energy efficiency of the transformer is analyzed in MATLAB version R2023b using measured no-load and load losses to generate efficiency, load characteristics under various operating conditions. Under varying load factor scenarios and based on Newfoundland’s 2025 grid intensity of 18 g CO₂e/kWh, the lifetime operational emissions are estimated to range from 0.19 t CO₂e under no-load operation to 4.4 t CO₂e under full-load conditions. A linear regression-based decarbonization model using Microsoft Excel projects grid intensity to reach net-zero around 2037, two years beyond the provincial target, indicating that post-2037 transformer losses will remain energetically relevant but carbon-neutral. Sensitivity analysis reveals that temporary overloading can substantially elevate lifetime emissions, emphasizing the value of smart-grid-enabled load management and optimal transformer sizing. Comparative assessment with fossil fuel-intensive provinces across Canada demonstrates the dominant influence of grid generation mix on life-cycle emissions. Additionally, refurbishment scenarios indicate up to 50% reduction in cradle-to-gate emissions through material reuse and oil reclamation. The findings establish a scalable framework for integrating grid decarbonization trajectories, life-cycle carbon modelling, and circular-economy strategies into sustainable distribution network planning and transformer asset management. Full article