Search Results (465)

Scope 3.1 emissions from purchased goods and services often represent a substantial share of corporate greenhouse gas footprints, yet their quantification is characterized by high uncertainty and limited transparency. In practice, organizations frequently rely on weight-based secondary emission factors, which can vary substantially depending on underlying assumptions such as production technology or geographical origin. Existing standards and data quality approaches provide important guidance on representativeness, reliability, and data exchange, but offer limited operational support for selecting appropriate emission factors. This study addresses this practical challenge by examining emission-factor variability for selected material groups, identifying key influencing factors, and developing a qualitative decision-support framework for evaluating, selecting, and documenting secondary emission factors in Scope 3.1 accounting. The results demonstrate that emission factors for the same material can differ by more than an order of magnitude, leading to substantial deviations in carbon footprint results if selected inconsistently. The proposed framework, while not replacing supplier-specific primary data or formal data-quality assessment, reduces selection-related uncertainty, and supports more reliable carbon accounting, particularly in data-constrained supply chain contexts. By providing a transparent screening logic for early-stage Scope 3.1, the study enables more informed sustainability and procurement decisions. Full article

This study presents a cradle-to-grave Life-Cycle Assessment of a multifunctional building-integrated photovoltaic (BIPV) skylight system combining a recycled aluminum frame, double-glazing unit, semi-transparent cadmium telluride (CdTe) photovoltaic glass, and an organic phase change material (PCM) for passive thermal regulation. Assessed over a 30-year service life in accordance with EN 15804+A2 using One Click LCA, the system is evaluated across 13 environmental impact categories for a declared unit of 0.72 m². Results show that materials production is the dominant environmental driver across all categories, contributing 72.0% of total GWP (78.00 kg CO₂-eq). Component replacement is the second contributor with 9.8% of GWP. End-of-life burdens account for 7.7% of cradle-to-grave GWP. When Module D credits are included, the system achieves an indicative net GWP balance of −808.34 kg CO₂-eq, that is conditional on a static Romanian grid-mix assumption; under progressive grid decarbonization this benefit is reduced, so the figure should be read as scenario-dependent potential rather than an immutable property of the product. Abiotic depletion of mineral elements is the only category where Module D does not fully offset system burdens, highlighting the relevance of critical raw material considerations for CdTe technologies. These findings demonstrate that BIPV depend on low-impact manufacturing and underscore the importance of multi-indicator LCA as the appropriate evaluation framework for integrated energy-generating building products. Full article

In the leveling process of ultra-high-strength steel plates, sample scarcity—driven by high prototyping costs and small-batch production—coupled with a narrow and unevenly distributed feasible region due to high yield-to-tensile ratios and limited ductility, impedes the balanced optimization of plate shape quality and energy consumption. To address this issue, this paper develops an optimization framework for the balanced trade-off between these two objectives. First, a high-precision response surface model based on Box–Behnken experimental design and finite element simulation was constructed using initial wave height, entry roll reduction, exit roll reduction, and leveling speed as key process parameters; peak residual stress difference (characterizing potential sheet quality) and leveling energy consumption as co-optimization objectives; and post-leveling flatness as a constraint. Next, by introducing the NSGA-II multi-objective genetic algorithm, the Pareto optimal solution set for the quality and energy efficiency objectives was obtained, clearly revealing the trade-off relationship between the two; furthermore, the TOPSIS decision-making method was employed to select the comprehensive optimal process scheme that achieves a balance between quality and energy efficiency from the Pareto solution set. An adaptive recommendation curve for the leveling process parameters of MS1500 ultra-high-strength steel plates was established, covering an initial wave height range of 10.5–14.6 mm, thereby enabling intelligent parameter matching based on different incoming material conditions. Finally, industrial validation demonstrated that this optimized scheme significantly reduced leveling energy consumption while ensuring that post-leveling flatness meets the high-quality requirement of less than 3.5 mm·m⁻¹. This achieves a balanced optimization of quality and energy efficiency. This study provides a reliable theoretical basis and practical engineering solution for the efficient and environmentally friendly leveling production of ultra-high-strength steel. Full article

Background: As a traditional Chinese exercise, Wushu has been shown to effectively promote balance and postural stability in various populations. Preschoolers’ capacity for balance control, including static, dynamic, and dual-task balance, is linked to the later development of stability skills in adulthood. However, studies of Wushu intervention focusing on balance ability and the related physical fitness in preschool children are limited. Objectives: This study investigated the effects of a 10-week Wushu program on static, dynamic dual-task balance and physical fitness in children 5–6 years old. Methods: Seventy-three participants were randomly divided into an intervention (INT, n = 39) and a control (CON, n = 34) group. The INT group participated in a 10-week Wushu program that included three 30 min sessions per week, while the CON group engaged in unstructured free play with purposely designed materials. The three key primary outcomes were dominant-leg stance for static balance, the balance beam walk for dynamic balance, and the center of pressure (CoP) path length obtained via a force platform during dual-task balance testing, in which the participants were instructed to count numbers backward. The five derived primary outcomes were non-dominant-leg stance, CoP ML path length, CoP AP path length, CoP sway velocity, and CoP sway area. Secondary outcomes were physical fitness indicators, including sit and reach, grip strength, standing long jump (SLJ), countermovement jump (CMJ), 15 m zigzag run, double-leg continuous jump, height and body weight. The analysis of the outcomes was conducted using analysis of covariance (ANCOVA) and Pearson correlation. Results: At baseline, the CON and INT groups did not differ significantly. The INT demonstrated significant enhancements in comparison with CON in the dominant and non-dominant-leg stance (p = 0.017 and p = 0.005, respectively), the balance beam walk, SLJ, 15 m zigzag run and double-leg continuous jump (all p < 0.05), along with the mediolateral CoP path length (p = 0.012). A strong correlation was found between the balance beam walk and the double-leg continuous jump (r = 0.55, p = 0.001), and between the balance beam walk and the 15 m zigzag run (r = 0.43, p = 0.015). Conclusions: The present study demonstrates that a 10-week Wushu program significantly enhances preschool children’s static balance, dynamic balance, and mediolateral postural control during dual-task condition. The improvements in dynamic balance are correlated with lower-limb coordination and jumping agility. Full article

This study presents a data-driven evaluation of recycled-aggregate gypsum composites by examining the relationships between dry density, mechanical performance, thermal conductivity, and formaldehyde adsorption. Analysis of published experimental data shows that dry density is the primary parameter governing overall material performance. Compressive strength increases with density, whereas lower-density composites provide superior thermal insulation. An optimal multifunctional performance range was identified at 900–1100 kg/m³, where a favorable balance between strength and insulation efficiency is achieved. Aggregate type also influences performance: polymer-based aggregates produce the greatest density reduction, biomass-derived aggregates offer a balanced combination of properties, and mineral-based aggregates generally maintain higher stiffness. Assessment of environmental functionality indicates that conventional gypsum composites possess limited formaldehyde and CO₂ adsorption capacity, although biochar and other bio-based modifications can significantly enhance adsorption performance. These findings provide a practical framework for designing sustainable gypsum composites with balanced structural, thermal, and indoor air quality benefits. Full article

Hydrophobic silica aerogels are widely used as thermal-insulation materials, but the thermal decomposition of their organic surface groups may affect their stability and safety during high-temperature service. In this study, ambient-pressure-dried silica aerogels modified with trimethylsilyl, dimethylsilyl, and methylsilyl groups were prepared and denoted as TSA, DSA, and MSA, respectively, to clarify how the degree of methyl substitution in the surface modifier controls the pyrolysis behavior of hydrophobic silica aerogels. Thermogravimetric analysis at different heating rates was combined with TG-FTIR, a model-free kinetic analysis, a model-fitting analysis and thermodynamic calculation. With decreasing methyl substitution from TSA to MSA, the aerogel framework became denser, the specific surface area decreased, and the contribution of solid-phase heat transfer increased slightly. The main pyrolysis process occurred at 250–800 °C and involved multiple overlapping reactions. The average activation energies of TSA, DSA, and MSA were 241.4, 246.6, and 285.5 kJ/mol according to the Kissinger–Akahira–Sunose (KAS) method and 243.0, 248.2, and 289.0 kJ/mol according to the Flynn–Wall–Ozawa (FWO) method, respectively. The higher activation energy of MSA indicates that the more condensed silica-rich framework and lower organic methyl content improves its resistance to the main degradation process. The model-fitting analysis further suggested an A1/2 mechanism for TSA and A2/5 mechanisms for DSA and MSA. TG-FTIR further confirmed the evolution of CO₂, H₂O, CH₄, and C₂H₄ and revealed distinct gas-release behaviors among the three samples. These results demonstrate that the surface methyl-substitution structure governs the balance between hydrophobic modification, pore-structure preservation, pyrolysis resistance, and volatile-product release, providing a basis for selecting surface modifiers for thermally stable silica-aerogel insulation materials under oxygen-limited high-temperature conditions. Full article

The residential sector accounts for a significant portion of global energy demand, which can be met through sustainable alternatives such as solar energy. This study evaluated the energy, exergy, environmental, and exergy-sustainability performance of three waste heat recovery configurations (double-loop organic Rankine cycle—DORC, Kalina cycle—KC, and organic Rankine cycle—ORC) coupled to a supercritical CO₂ Brayton cycle with intercooling and reheating, designed to meet the demand of a residential complex of 120 homes in the Colombian Caribbean region, built with four different materials, using a concentrated solar power tower as the heat source. Mass, energy, and exergy balances were performed, along with a life cycle analysis, sizing the systems to supply a cooling load of 133 kW. The results show that the three configurations meet the required demand, with energy efficiencies above 50%: sCO₂-DORC (51.7%), sCO₂-ORC (51.61%), and sCO₂-KC (51.32%), with a maximum exergy efficiency for sCO₂-DORC (24.3%). The environmental analysis indicates that the construction phase accounts for more than 95% of total emissions. Overall, the results confirm the viability of these configurations for residential applications, promoting the integration of renewable energies and supporting the regional energy transition. Full article

Cement manufacturing is a major source of carbon dioxide (CO₂) emissions globally. Cement replacement materials are increasingly used to minimize the environmental impact of concrete production. In the present study, the mechanical and environmental performance of concrete mixtures containing fly ash and recycled glass powder as partial cement replacements at levels of 10%, 20%, and 30% were investigated. Workability, unit weight, compressive strength, and water permeability tests were conducted to evaluate the effects of replacements on concrete behavior. Carbon emissions decreased as the substitution ratio increased, with the highest reduction (28.9%) observed in the mixture containing 30% fly ash. Compressive strength values ranged from 21.9 to 27.0 MPa, indicating that all mixtures fell within the intended strength range. Two types of cement replacements—fly ash (FA) and recycled glass powder (GP)—were evaluated separately. Compared to GP mixtures, FA mixtures generally exhibited lower permeability (up to 50%) and better strength retention (up to 9.6 percentage points), though both materials contributed to reducing embodied carbon. The mixture containing 30% fly ash demonstrated the highest environmental efficiency, with a carbon intensity of 10.84 kg CO₂/MPa, corresponding to a 19.2% reduction compared with the control. For recycled glass powder, the 20% replacement level offered the most balanced performance, while higher replacement ratios led to more pronounced strength losses. This study provides a direct comparison of FA and GP under identical mixture conditions using performance-normalized environmental indicators. The results indicate that, under the tested conditions, fly ash exhibits a better combination of carbon emission reduction and mechanical strength than recycled glass powder. Full article

This review aims to clarify the molecular design principles and operational challenges of photoinduced electron transfer (PET) and photoredox processes in metal complexes. The manuscript is structured to include a survey of established conventional systems, such as Ru complexes, followed by our own research on cost-effective photosensitizers for dye-sensitized solar cells (DSSCs) and carbon dioxide (CO₂) reduction. Crucially, our main conclusion emphasizes that achieving high optoelectronic efficiency requires the balanced optimization of excited-state lifetimes, orbital distributions, and matrix environments, rather than a simplistic “one-size-fits-all” approach. Finally, based on the fundamental principles of metal complexes and photocatalytic materials, we offer a critical analysis of the practical challenges and reasons behind our unsuccessful experimental outcomes. Thus, this study provides a perspective on unsuccessful molecular design, comparing typical examples. Full article

Spinel NiCo₂O₄ has emerged as a promising microwave absorption material due to its unique crystal structure and abundant defect sites. Nevertheless, its low intrinsic electrical conductivity leads to insufficient conductive loss and unsatisfactory high-frequency impedance matching, severely limiting the simultaneous realization of strong electromagnetic attenuation and broad absorption bandwidth. Fe³⁺ doping is an effective modification strategy for NiCo₂O₄ by virtue of its matched ionic radius and dual modulation capability for dielectric and magnetic properties. Herein, pristine and Fe-doped NiCo₂O₄ absorbers with different doping contents (4%, 6%, 8%) were fabricated via a hydrothermal–calcination route, and the correlation between Fe doping concentration, microstructure, electronic structure, electromagnetic properties, and microwave absorption performance was systematically investigated. Benefiting from moderate 6% Fe doping, the optimized F6 sample exhibits a refined porous nano-agglomerate structure, which provides abundant heterogeneous interfaces and pore channels for electromagnetic wave scattering and attenuation. The introduced oxygen vacancies and balanced Ni²⁺/Ni³⁺, Co²⁺/Co³⁺, and Fe²⁺/Fe³⁺ mixed-valence states effectively strengthen interfacial and dipole polarization, while the optimized electrical conductivity and magnetic properties synergistically boost conductive and magnetic losses. Owing to the dual-loss synergism and superior impedance matching (58% proportion of Δ < 0.4), the F6 sample achieves an excellent minimum reflection loss of −62.7 dB at 2.2 mm and a wide effective absorption bandwidth of 4.6 GHz. This work clarifies the intrinsic structure–performance mechanism of Fe-doped NiCo₂O₄, providing a reliable and feasible strategy for the design and preparation of high-performance spinel-type microwave-absorbing materials. Full article

This study aims to systematically evaluate the balancing mechanism between road performance, carbon emissions, and economic cost when selecting asphalt materials for severe cold regions, filling the gap in multi-criteria decision-making for composite chemical modifications. To address alternating temperatures, heavy traffic, and modified asphalt transport difficulties, this study presents a novel evaluation framework focusing on the performance–environmental–cost nexus of a desulfurized rubber powder composite SBS-modified asphalt mixture, which provides a clear technological breakthrough for high-ratio scrap tire recycling in seasonal frost zones. Two reference mixtures serve as comparisons: a conventional rubber powder composite SBS (styrene–butadiene–styrene triblock)-modified asphalt mixture (CR-SBS) and an SBS-modified asphalt mixture (SBS). A comparative experiment was conducted between the two materials and the SBS-modified asphalt mixture (ACR-SBS) compounded with desulfurized rubber powder. High-temperature stability was tested by the rutting test, low-temperature crack resistance by the beam bending test, and water stability by the immersion Marshall and freeze–thaw splitting tests. Life cycle carbon emissions and economic costs were quantified from raw material acquisition to construction. The results show that desulfurized rubber powder composite with ACR-SBS delivers the most superior overall road performance. However, it also generates the highest life cycle carbon footprint. Its total carbon emission reaches 162,800 kgCO₂eq, which is 13.7% (19,600 kgCO₂eq) higher than SBS (143,200 kgCO₂eq) and 7.7% (11,600 kgCO₂eq) higher than CR-SBS (151,200 kgCO₂eq). The total cost of ACR-SBS is 391,000 CNY, which is 1.5% (6000 CNY) higher than SBS (385,000 CNY) and 1.3% (5000 CNY) lower than CR-SBS (396,000 CNY). These findings provide a basis for the selection of high-performance, low-carbon, and economical composite-modified asphalt in severe cold regions. Full article

Background: Postural disability develops in almost all patients with diabetic polyneuropathy (DPN). While transcutaneous electrical nerve stimulation (TENS) has proven effective in regressing sensory and motor impairments, its efficacy in improving postural control remains insufficiently studied. Purpose: To evaluate and compare the efficacy of direct peroneal and tibial high-frequency low-amplitude (HFLA) TENS and low-frequency high-amplitude (LFHA) TENS in correcting DPN-related postural disability, among European female patients without a documented history of falls, motor deficits, or pronounced electromyographic impairments, using computerized static posturography and the tandem walk test. Materials and methods: In this single-center, three-arm, randomized controlled trial (registration number: ISRCTN47534508, 3 December 2024), we conducted a longitudinal prospective analysis of European women with DPN-related postural disability. All enrolled patients were non-fallers with no motor deficits and baseline compound muscle action potential (CMAP) amplitudes of the peroneal and tibial nerves of at least 1.5 mV. The intervention groups received HFLA TENS (n = 24) or LFHA TENS (n = 25), while the control group underwent sham TENS (n = 24). Primary endpoints were assessed via static posturography and the tandem walk test (TWT); secondary endpoints were evaluated using hypoesthesia and pain evaluation, the Modified Clinical Test of Sensory Interaction in Balance (mCTSIB), and electromyography. Assessments were performed before treatment, immediately post-treatment, and at the conclusion of a 2-month follow-up period. Results: Comparative analysis incorporating the Bonferroni adjustment demonstrated that LFHA TENS is significantly superior to HFLA TENS. Post-treatment, LFHA TENS induced a reduction in envelope area by 20.7% under the eyes-open (EO) condition (p < α_adj; α_adj = 0.0028) and 32.9% under the eyes-closed (EC) condition (p < α_adj; α_adj = 0.0028), alongside a 16.6% decrease in the Romberg uotient (RQ) (p < α_adj; α_adj = 0.0056). Furthermore, LFHA TENS elicited a significant 39.0% reduction in velocity of CoP sway (VCS) under the EO condition (p < α_adj; α_adj = 0.0042), and decreased total CoP sway excursion by an average of 35.8% (EO) (p < α_adj; α_adj = 0.0042) and 43.8% (EC) (p < α_adj; α_adj = 0.0042) compared to baseline. In contrast, no statistically significant changes in these parameters were observed after HFLA TENS. Ultimately, LFHA TENS outperformed HFLA TENS in improving postural stability by 7.04% under the EO condition (p < α_adj; α_adj = 0.0042) and by 25.5% under the EC condition (p < α_adj; α_adj = 0.0042) in both the tandem walk test (TWT) and the Modified Clinical Test of Sensory Interaction on Balance (mCTSIB). Notably, a statistically significant increase in the CMAP amplitude of the affected peroneal nerves by 22.2% was observed exclusively following LFHA TENS treatment (p < α_adj; α_adj = 0.0056). Conclusions: The clinical efficacy of direct peroneal and tibial TENS compared to sham stimulation in reducing postural disability during both static and dynamic conditions was established in European female patients with moderate-to-severe DPN and unremarkable EMG impairments. Comparative analysis reveals a clear therapeutic superiority of LFHA TENS over HFLA TENS, as evidenced by significantly greater improvements in both posturographic parameters (envelope area, total CoP excursion under EO and EC conditions, and VCS under the EO condition) and functional clinical tests (TWT and mCTSIB), demonstrating long-term stability for up to 2 months post-intervention. Full article

This study investigates the use of mussel shells (MSs), a biogenic by-product of the food industry, as a partial replacement for ground granulated blast furnace slag (GBFS) in alkali-activated mortars. Given their high CaCO₃ content, MSs represent a sustainable secondary raw material that reduces both waste disposal burden and reliance on natural resources, while offering a low-carbon alternative to conventional cement-based binders. Alkali-activated mussel shell/slag mortars (AAMSs) were produced with MS replacement ratios of 0%, 5%, 10%, 15%, and 20% by mass of GBFS. Sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃) were used as alkaline activators. Fresh specimens were cured at 60 °C for 48 h. The experimental program included workability, compressive and flexural strength, water absorption, porosity, density, capillarity, ultrasonic pulse velocity (UPV), and freeze–thaw (F-T) resistance tests. Increasing MS content slightly reduced flowability and mechanical strength, while increasing water absorption, porosity, and capillarity. The M0 series achieved the highest 28-day compressive strength (54.06 MPa), while M15 exhibited the highest flexural strength (5.23 MPa). Following F-T cycling, the 5% and 10% MS series demonstrated the best compressive strength (30 MPa). The 10% MS exhibits a relatively balanced overall performance, providing the best balance between mechanical performance, F-T resistance, and microstructural stability, as confirmed by scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) analyses showing elevated Ca/Si ratios and the formation of Ca-rich crystalline phases. Full article

The rapidly increasing global demand for high-performance thermal insulation materials necessitates a significant shift towards more sustainable and cost-effective solutions. This study unveils a novel and efficient pathway to synthesize engineered cordierite, a highly coveted magnesium aluminosilicate ceramic, by intelligently harnessing biogenic silica extracted directly from rice husk. Rice husk, an abundant agricultural by-product, represents a readily available and often underutilized resource. The methodology involved a precise precipitation method to successfully yield high-purity silica from rice husk ash. This extracted silica was then meticulously combined with commercial magnesium oxide (MgO) and aluminum oxide (Al₂O₃) through a solid-state reaction to synthesize the desired cordierite. The study systematically investigated the profound impact of various sintering temperatures, ranging from 850 °C to 1100 °C, on both the cordierite yield and its crucial physicochemical properties. Our experiments revealed that a sintering temperature of 1100 °C achieved a remarkable 66.5% cordierite yield. Beyond yield, the material processed at 1100 °C exhibited exceptional mechanical and thermal characteristics: a compressive strength of 65 kN/m², a flexural strength of 44 kN/m², a tensile strength of 17.5 kN/m², and a remarkably low thermal conductivity of just 3.2 W/m·K. These attributes match the mechanical requirements for structural insulation, with a thermal conductivity of 3.2 W/m·K. While higher than some high-porosity commercial cordierites (typically 1.2–2.0 W/m·K), the biogenic version offers a 40% reduction in production energy and utilizes 100% recycled silica, balancing thermal performance with superior sustainability. By utilizing agricultural waste, this method reduces CO₂ emissions associated with mineral extraction and minimizes reliance on non-renewable raw materials, providing a practical pathway for the circular economy. Full article

Models of thermal runaway propagation in lithium-ion batteries are widely used for thermal safety analysis. Current methods, primarily lumped-parameter and 3D models, face challenges in balancing accuracy with computational efficiency. Three-dimensional models offer high accuracy at high computational cost, while lumped-parameter models are faster but less accurate. For instance, the battery shell is included in lumped-parameter models but often omitted in 3D models. This study focuses on a 37 Ah ternary lithium-ion battery, with Li(NiCoMn)_1/3O₂ as the cathode material and graphite as the anode material. The propagation of thermal runaway in the battery array is triggered by nail penetration. A lithium-ion battery thermal runaway propagation model is proposed, combining the lumped-parameter method with 3D modeling. The model primarily describes the heat transfer characteristics of the shell using a series connection of thermal capacitance and several thermal resistances. The shell temperature is then calculated by weighting the temperatures associated with the thermal capacitance and thermal resistances using specific weight coefficients. The joint model is detailed and applied to study thermal runaway propagation in one- and two-dimensional battery arrays. For the one-dimensional array, based on the three-dimensional simulation data and calculation time, the joint model shows only a 1.32% average deviation in propagation time compared to full 3D simulation, while maintaining good temperature agreement. It also reduces solution time by 70.22%. These findings confirm that the proposed model effectively enhances both the efficiency and accuracy of thermal runaway simulations, supporting improved safety analysis for lithium-ion battery systems. Full article