Search Results (21,993)

Existing office buildings in Australia contribute to 24% of the nation’s electricity consumption and 10% of greenhouse gas emissions, with energy use projected to rise by 84%. Meeting the 2050 sustainability target and United Nations (UN) 17 Sustainable Development Goals (SDGs) requires improving sustainability within existing office buildings. This systematic review examines net zero energy and climate resilience strategies in these buildings by analysing 74 studies from scholarly literature, government reports, and industry publications. The literature search was conducted across Scopus, Google Scholar, and Web of Science databases, with the final search in early 2025. Studies were selected based on keywords and research parameters. A narrative synthesis identified key technologies, evaluating the integration of net zero principles with climate resilience to enhance energy efficiency through HVAC modifications. Technologies like heat pumps, energy recovery ventilators, thermal energy storage, and phase change materials (PCMs) have been identified as crucial in reducing HVAC energy usage intensity (EUI). Lighting control and plug load management advancements are examined for reducing electricity demand. This review highlights the gap between academic research and practical applications, emphasising the need for comprehensive field studies to provide long-term performance data. Current regulatory frameworks influencing the net zero transition are discussed, with recommendations for policy actions and future research. This study links net zero performance with climate adaptation objectives for existing office buildings and provides recommendations for future research, retrofit planning, and policy development. Full article

Hydrogen permeation parameters of PA12 were obtained through high-pressure hydrogen permeation experiments conducted under various temperature and pressure conditions. The temperature-dependent mechanism governing the hydrogen permeation behavior of PA12 was further examined using dynamic mechanical analysis (DMA). A multi-field coupled numerical model was established and validated against the experimental results. Based on the validated numerical approach, the hydrogen permeation behavior of a type IV hydrogen storage vessel with local reinforcement was investigated. The results show that both temperature and pressure have a significant influence on the hydrogen permeation performance of PA12. When the temperature is below the glass transition temperature (Tg) of PA12 (48.34 °C), the diffusion coefficient remains low, whereas temperatures above the Tg led to a marked increase in the diffusion coefficient. In addition, the local reinforcement patch effectively prolongs the time required to reach steady-state permeation, reduces the hydrogen permeation flux before and after steady state, and enhances the overall resistance to hydrogen permeation of the type IV vessel. As the diffusion coefficient of the liner material increases, the hydrogen diffusion rate increases substantially, leading to greater hydrogen accumulation in the dome region and higher permeation levels both before and after steady state. These findings provide theoretical guidance and design references for optimizing the hydrogen-resistant performance of type IV hydrogen storage vessels. Full article

In regions with hot summers and cold winters, elderly care buildings face the dual challenges of high energy consumption and stringent thermal comfort requirements. Using Nanchang as a case study, this research presents an optimization approach that integrates phase change material (PCM) walls with the window-to-wall ratio (WWR). PCM wall performance was tested experimentally, and EnergyPlus simulations were conducted to assess building energy use for WWR values ranging from 0.25 to 0.50, with and without PCM. The phase change material (PCM) used in this study is paraffin (an organic phase change material), which has a melting point of 26 °C and can store and release heat during temperature fluctuations. The experimental results show that PCM walls effectively reduce heat transfer, lowering the surface temperatures of external, central, and internal walls by 3.9 °C, 3.8 °C, and 3.7 °C, respectively, compared to walls without PCM. The simulation results predict that the PCM wall can reduce air conditioning energy consumption by 8.2% in summer and total annual energy consumption by 14.2%. The impact of WWR is orientation-dependent: east and west façades experience significant cooling penalties as WWR increases and should be maintained at or below 0.30; the south façade achieves optimal performance at a WWR of 0.40, with the lowest total energy load (111.2 kW·h·m-2); and the north façade performs best at the lower bound (WWR = 0.25). Under the combined strategy (south wall with PCM and WWR = 0.40), annual total energy consumption is reduced by 9.8% compared to the baseline (no PCM), with indoor temperatures maintained between 18 and 26 °C. This range is selected based on international thermal comfort standards (e.g., ASHRAE) and comfort research specifically targeting the elderly population, ensuring comfort for elderly occupants. These findings offer valuable guidance for energy-efficient design in similar climates and demonstrate that the synergy between PCM and WWR can reduce energy consumption while maintaining thermal comfort. Full article

The evolution of modern warfare and civil exploration requires platforms that can operate seamlessly across the air–water interface. The folding-wing Hybrid Air and Underwater Vehicle (FUD) has emerged as a transformative solution, combining the high-speed cruising capabilities of fixed-wing aircraft with the stealth characteristics of underwater navigation. This review thoroughly analyzes the advancements and challenges in folding-wing FUD technology. The discussion is framed around four interconnected pillars: the overall design driven by morphing technology, adaptation of the propulsion system, multi-phase dynamic modeling and control, and experimental verification. The paper systematically compares existing technical pathways, including lateral and longitudinal folding mechanisms, as well as dual-use and hybrid propulsion strategies. The analysis indicates that, although significant progress has been made with prototypes demonstrating the ability to transition between air and water, core challenges persist. These challenges include underwater endurance, structural reliability under impact loads, and effective integration of the power system. Additionally, this paper explores promising application scenarios in both military and civilian domains, discussing future development trends that focus on intelligence, integration, and clustering. This review not only consolidates the current state of technology but also emphasizes the necessity for interdisciplinary approaches. By combining advanced materials, computational intelligence, and robust control systems, we can overcome existing barriers to progress. In conclusion, FUD technology is moving from conceptual validation to practical engineering applications, positioning itself to become a crucial asset in future cross-domain operations. Full article

Background and Objectives: The vitamin K epoxide reductase complex subunit 1 (VKORC1) plays a central role in the vitamin K cycle, which is essential for γ-carboxylation of multiple bone-related proteins. Genetic variants in VKORC1 may influence bone mineral density (BMD) and osteoporosis risk. Materials and Methods: A systematic review and meta-analysis were conducted to evaluate the association between VKORC1 polymorphisms and osteopenia and osteoporosis. Relevant studies were identified through PubMed, Scopus, and Web of Science databases. Data on study characteristics, genotypes, BMD measurement, ethnicity, sex, and menopausal status were extracted. Results: Six studies comprising 7335 participants were included. All studies assessed BMD using dual-energy X-ray absorptiometry (DXA). The mean participant age ranged from 41.9 to 63.7 years. The VKORC1 variants most frequently studied, which were included in the meta-analysis, were rs9923231 and rs9934438. The overall effect of VKORC1 risk alleles on osteopenia/osteoporosis was significant with a p = 0.041 (fixed effects OR = 1.16, 95% CI = 1.01–1.35). Heterogeneity among studies was insignificant (I² = 0%, p = 0.893). Conclusions: A modest association was observed for the VKORC1 variants. The current body of evidence requires further studies to elucidate whether VKORC1 polymorphisms have a clinically meaningful role in bone health. Full article

A well construction plan includes a drilling program, drilling fluids, casing-setting-depth selection, casing-grade-combination design, bit selection, cementing, and a wellhead design. Casing-setting-depth selection techniques are an integral part of the construction of oil and gas wells, where setting-depth selection methods rely on both safety and economics. In this study, a new casing-setting-depth selection method is developed. This new method is based on the estimation of the fracturing pressure using the Mohr–Coulomb failure criterion. To validate this new casing-setting-depth selection method, ten core samples, representing ten underground formations in the Saudi lithological column, were tested for uniaxial compressive and tensile strengths. The results were utilized to establish rock failure criteria and estimate casing setting depth using a newly proposed casing-setting-depth selection method based on the Mohr–Coulomb failure criterion and compared to other traditional casing-setting-depth estimation methods. The results demonstrated that the Hubbert & Willis method provided a very narrow safe mud window compared to the other methods, while the leak-off, Eaton, Mathews & Kelly, and other methods provided more economical results. On the other hand, the Mohr–Coulomb method provided the widest and most economical safe mud window compared to all other traditional methods. One of the main requirements of the Mohr–Coulomb casing-setting-depth selection method is that it either requires appreciable core samples from various depths to be tested in the laboratory for their mechanical properties and failure criteria, or that core-calibrated well logs be used. Additionally, relying on Mohr–Coulomb casing-setting-depth selection methods requires the use of filtration loss control materials to seal any microcracks that may form. Economical comparisons in terms of casing string number and length yielded that Eaton, leak-off, and Mathews and Kelly methods reduced casing cost by 31% compared to Hubbert and Willis methods. On the other hand, the new casing-setting-depth selection method based on the Mohr–Coulomb method reduced casing costs by 41% compared with the Hubbert and Willis methods and by 10% compared with the leak-off and Mathews and Kelly methods. Therefore, this study provides a new proof of concept for developing an efficient method for selecting the casing setting depth for oil and gas wells. Full article

With the increasing requirements for “Green Mine” construction, Cemented Tailings Backfill (CTB) has emerged as the preferred strategy for solid waste management and ground pressure control in underground metal mines. However, full tailings, characterized by wide particle size distribution and high fine-grained content, exhibit complex physicochemical properties that lead to significant non-linear behavior in slurry rheology and strength evolution, posing challenges for accurate prediction using traditional empirical formulas. Addressing the issues of significant strength fluctuations and difficulties in mix proportion optimization in a specific lead–zinc mine, this study systematically conducted physicochemical characterizations, slurry sedimentation and transport performance evaluations, and mechanical strength tests. Through multi-factor coupling experiments, the synergistic effects of cement type, cement-to-tailings (c/t) ratio, slurry concentration, and curing age on backfill performance were elucidated. Quantitative results indicate that solids mass concentration is the critical factor determining transportability. Concentrations exceeding 68% effectively mitigate segregation and stratification during the filling process while maintaining optimal fluidity. Regarding mechanical properties, the c/t ratio and concentration show a significant positive correlation with Uniaxial Compressive Strength (UCS). For instance, with a 74% concentration and 1:4 c/t ratio, the 3-day strength increased by 1.4 times compared to the 68% concentration, with this increment expanding to 2.0 times by 28 days. Furthermore, a comparative analysis of four cement types revealed that 42.5# cement offers superior techno-economic indicators in terms of reducing binder consumption and enhancing early-age strength. This research not only establishes an optimized mix proportion scheme tailored to the operational requirements of the lead–zinc mine but also provides a quantitative scientific basis and theoretical framework for the material design and safe production of CTB systems incorporating high fine-grained full tailings. Full article

The automotive industry’s use of aluminum alloys continues to rise, driven by efforts to reduce vehicle weight—and thus fuel consumption—amid growing demand for larger vehicles such as SUVs, as well as the accelerating shift to electric vehicles and the expanding global vehicle fleet. These trends create major challenges for the aluminum sector. This paper provides a narrative literature review of available and published data, primarily from the period 2020–2025, examining new trends, challenges and opportunities regarding the implementation of recycled aluminum as a substitute for primary aluminum in the European automotive industry. The goal is to develop a discussion based on the answer to the following three issues: (1) What opportunities exist for increasing the production of recycled aluminum, given the imperative to conserve diminishing raw materials required for primary aluminum production? (2) What methods could enhance the obtaining of recycled aluminum over primary aluminum? (3) How might the technological barriers that hinder the wider use of recycled aluminum be overcome? This review finds that recycled aluminum availability in the EU automotive sector is improving due to rising demand for recycled material over primary aluminum—supported by a steadily growing scrap supply—alongside the development of advanced recycling strategies capable of producing high-purity recycled alloys. Full article

The design of aircraft components is a complex process that must simultaneously account for environmental impact, manufacturability, cost and structural performance to meet modern regulatory requirements and sustainability objectives. When these factors are integrated from the early design stages, the approach transcends traditional eco-design and becomes a genuinely sustainability-oriented design methodology. This study proposes a sustainability-driven design framework for aircraft components and demonstrates its application to a fuselage panel consisting of a curved skin, four frames, seven stringers, and twenty-four clips. The design variables investigated include the material selection, joining methods, and subcomponent thicknesses. The design space is constructed through a combinatorial generation process coupled with compatibility and feasibility constraints. Sustainability criteria are evaluated using a combination of parametric Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) regression models, parametric Finite Element Analysis (FEA), and Random Forest surrogate modeling trained on a stratified set of simulation results. Two methodological pathways are introduced: 1. Cluster-based optimization, involving customized clustering followed by multi-criteria decision-making (MCDM) within each cluster. 2. Global optimization, performed across the full decision matrix using Pareto front analysis and MCDM techniques. A stability analysis of five objective-weighting methods and four normalization techniques is conducted to identify the most robust methodological configuration. The results—based on a full cradle-to-grave assessment that includes the use phase over a 30-year A319 aircraft operational lifetime—show that the thermoplastic CFRP panel joined by welding emerges as the most sustainable design alternative. Full article

Metal–organic frameworks (MOFs) typically exist in the form of powders or dispersed crystals, which limits their direct application in practical engineering scenarios that require monolithic structures and processability. To address this issue, the present study successfully anchored MOF (zeolitic imidazolate framework-8, ZIF-8) nanocrystals within a porous silicon carbide (p-SiC) substrate via a facile in situ growth strategy, achieving both stable macroscopic loading and intimate microscopic interfacial bonding. The resulting ZIF-8/p-SiC composite exhibits a hierarchical porous structure, with a specific surface area approximately 183 times higher than that of the raw p-SiC, alongside a substantially enhanced CO₂ adsorption capacity. By utilizing a low-cost p-SiC support and mild ZIF-8 synthesis conditions, this work demonstrates excellent reproducibility and scalability, providing a facile and effective pathway for fabricating MOF/porous media composite systems that possess both superior mechanical properties and tailored pore structures. Additionally, the developed MOF/p-SiC composites can serve as controllable rock-analog porous media, offering new perspectives for investigating MOF-rock interfacial interactions and CO₂ geological sequestration mechanisms, thereby establishing an organic link between fundamental materials science and geological engineering applications. Full article

Diffractive optical elements (DOEs) offer significant advantages over conventional refractive optics, particularly in non-visible spectral regions such as ultraviolet, gamma rays, and X-rays, where material limitations restrict traditional optical components. Owing to their design flexibility, DOEs enable the generation of complex beam profiles—including circular, vortex, and Airy beams—across a wide range of wavelengths. Despite their structural simplicity and compatibility with micro- and nanoscale fabrication, conventional DOEs often suffer from limited focusing efficiency, frequently requiring additional refractive lenses that introduce optical aberrations, increased system complexity, and higher cost. In this work, we present an integrated design and fabrication approach for micro-scale diffractive optical elements capable of achieving high focusing performance without reliance on supplementary optical components. A machine learning-based decision tree method is employed to generate optimized writing paths, which are subsequently fabricated using direct laser lithography. The proposed integrated DOE structures enable efficient focusing of multiple customized beam profiles within a compact and standalone optical element. This approach improves optical efficiency while maintaining low fabrication cost and system simplicity. The demonstrated integrated micro-DOEs provide a scalable and versatile platform for advanced beam shaping and focusing applications in photonics, particularly where compactness and performance are critical. Full article

Background and Objectives: Although several meta-analyses have evaluated the effects of motor imagery (MI) on upper-limb recovery using the Fugl-Meyer Assessment for the Upper Extremity (FM-UE), evidence based on more specific (Action Research Arm Test, ARAT) and functional (Barthel Index, BI) outcomes remains scarce. This study examined the effect of MI combined with conventional rehabilitation therapy (CRT), which translates into meaningful improvements in upper-limb performance and functional independence after stroke, accounting for methodological quality and publication bias. Materials and Methods: A systematic review and meta-analysis were carried out in accordance with PRISMA recommendations, with prior registration in PROSPERO (CRD420251120044). Comprehensive searches were conducted across six electronic databases up to July 2025. The methodological rigor of the included studies was evaluated using the PEDro scale, and risk of bias was appraised with the Cochrane RoB 2 instrument. Random-effects models estimated pooled effect sizes (ESs) for the ARAT and BI, alongside analyses of heterogeneity, publication bias, and moderators. Results: Eleven RCTs (n = 425) were included. A small pooled improvement in ARAT was observed (ES = 0.25; 95% CI: 0.13–0.37; p < 0.001); however, this effect was rendered non-significant after correction for publication bias (ES = 0.08; 95% CI: −0.14–0.31). No significant differences were found for the BI (ES = 0.41; 95% CI: −0.35–1.18; p = 0.268), with substantial heterogeneity (I² = 96.6%). The mean PEDro score was 6.6, indicating moderate methodological quality. Conclusions: MI combined with CRT yields small and inconsistent effects on upper-limb recovery and no improvement in functional independence. Current evidence does not support its routine use in stroke rehabilitation. Well-designed, adequately powered randomized controlled trials employing standardized MI protocols are required to determine its true clinical relevance. Full article

Thermochromic smart windows are a promising technology to reduce energy consumption in buildings, particularly in tropical regions where cooling demands are high. Vanadium dioxide (VO₂) is the most studied thermochromic material due to its reversible semiconductor-to-metal transition near 68 °C. Conventional synthesis routes require long reaction times and post-annealing steps. In this work, we report a rapid hydrothermal synthesis of monoclinic VO₂(M) and tungsten-doped VO₂(M) powders obtained within only 6 h at 270 °C, using vanadyl sulfate as precursor and controlled precipitation at pH ≈ 8.5. Differential scanning calorimetry confirmed the reversible transition at 59 °C for the undoped VO₂, with a hysteresis of 18 °C, while tungsten doping reduced the transition temperature by ~17 °C per wt.% of W. X-ray diffraction verified the monoclinic phase with minor traces of VO₂(B), a non-thermochromic polymorph of VO₂, and microstructural analysis revealed crystallite sizes below 35 nm. Electron microscopy and dynamic light scattering confirmed particle sizes suitable for dispersion in polymeric matrices. This approach significantly reduces synthesis time compared to typical hydrothermal methods requiring 20–48 h and avoids further annealing. The resulting powders provide a low-cost and scalable route for fabricating thermochromic coatings with transition temperatures closer to ambient conditions, making them relevant for smart-window applications in tropical climates, where lower transition temperatures are generally regarded as beneficial. Full article

This study addresses the issues with traditional rolling protection bearings in vertical magnetic levitation flywheel energy storage systems (FESSs), which are prone to impact, wear, and temperature rise under abnormal conditions, such as drops. It designed a permanent magnet axial protection bearing based on a Halbach array, utilizing N42SH permanent magnet material. The five-layer Halbach array achieved a maximum axial magnetic force of 86 KN and a maximum air gap magnetic flux density of 2.2 T, meeting the application requirements. Simulation results, combined with rotor drop dynamics and thermal analysis, show that under an 8000 rpm drop condition, the permanent magnet bearing reduces radial and axial contact forces by approximately 60% and 54%, respectively, and wear by around 70%. Additionally, the maximum system temperature decreases from 109 °C to 74 °C, with a 32% reduction in temperature rise. Friction experimental analysis indicates that low frequency, low load, and moderate temperatures improve friction stability and reduce wear. Overall, the permanent magnet axial protective bearing effectively mitigates drop impact, reduces friction heat and wear, and enhances the safety and reliability of the flywheel energy storage system under abnormal working conditions, providing valuable theoretical support and a design reference for engineering applications. Full article

Background and Objectives: Soft tissue sarcomas account for approximately 7% of all malignant tumors in the pediatric population. Diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) measurements may provide early functional biomarkers of treatment response by reflecting changes in tumor cellularity. This study evaluated whether ADC-derived parameters can serve as quantitative biomarkers of neoadjuvant chemotherapy response in pediatric rhabdomyosarcoma. Materials and Methods: This retrospective single-center study included 14 patients aged ≤18 years with histopathologically confirmed rhabdomyosarcoma who underwent MRI before treatment and after three cycles of chemotherapy. Twenty-five patients were initially identified; eleven were excluded due to imaging artifacts or absence of baseline examination. ADC maps were generated on 1.5T and 3T scanners. Regions of interest were placed over the entire lesion and areas with the lowest ADC signal. Relative ADC (rADC) was calculated by normalizing tumor ADC to adjacent healthy muscle. Paired t-tests were used to compare pre- and post-treatment values. Results: At baseline, 13/14 patients (93%) demonstrated diffusion restriction. Mean ADC increased from 1.11 × 10⁻³ mm²/s (SD ± 0.48) at baseline to 1.63 × 10⁻³ mm²/s (SD ± 0.67) after treatment. The paired t-test for rADC yielded t = −3.089 (p = 0.0086, 95% CI: −0.79 to −0.14), indicating a statistically significant change. There was a significant difference between the ADC values of the entire lesion and the areas with the lowest signal in tumors with a heterogenic structure, t = 2.862, p = 0.013. Conclusions: ADC and rADC increased significantly after neoadjuvant chemotherapy in pediatric rhabdomyosarcoma, suggesting potential utility as early functional biomarkers of treatment response. These preliminary findings require validation in larger multicenter prospective studies with correlation to histopathological response and clinical outcomes before clinical implementation. Full article