Search Results (3,923)

Cementite (Fe₃C) plays a key role in determining the mechanical performance of pearlitic and heat-resistant steels, where both its intrinsic elastic properties and interfacial bonding with ferrite are critical. In this study, first-principles calculations based on density functional theory were employed to systematically investigate the elastic anisotropy of orthorhombic Fe₃C and the interfacial stability of α-Fe/Fe₃C with three typical orientation relationships (Isaichev, Bagaryatsky, and Pitsch–Petch). The calculated elastic constants of Fe₃C satisfy the mechanical stability criteria and reveal pronounced anisotropic behavior, indicating strong directional dependence of its deformation resistance. Interfacial models with optimized lattice matching demonstrate that the Isaichev orientation exhibits the lowest lattice mismatch (~1.71%), the smallest interface energy (0.55 J/m²), and the highest work of adhesion (4.29 J/m²), suggesting superior thermodynamic stability and interfacial bonding strength. In contrast, the Bagaryatsky and Pitsch–Petch interfaces exhibit larger lattice mismatch and more pronounced local interfacial distortion, resulting in higher interface energies and reduced interfacial stability. These findings provide atomic-scale insights into the structure–property relationship of Fe₃C and highlight the critical role of orientation relationships in governing interface stability. The results offer theoretical guidance for interface engineering and microstructure optimization in high-performance steels. Full article

Residential development in Kuwait is shaped by a state-led housing system, rapid urban expansion, extreme climatic conditions, and socio-cultural practices that influence how residents experience housing and neighborhoods. Existing social value and sustainability frameworks provide useful principles for evaluating development outcomes; however, they may require contextual adaptation to address issues that are particularly relevant to Kuwait, including housing allocation, intergenerational living, privacy, maintenance, access to essential facilities, and culturally appropriate communal space. This study develops a stakeholder-informed framework for evaluating the social value of residential property development in Kuwait. A sequential mixed-methods design was adopted. First, a literature review identified five preliminary domains: Political, Social, Economic, Environmental, and Urban and 25 initial indicators. Second, 28 semi-structured interviews were conducted with eight supply-side stakeholders and 20 demand-side stakeholders. Thematic analysis was used to refine the indicator set, resulting in six additional context-specific indicators and a 31-indicator framework. Third, the same participants completed a structured questionnaire using a six-category scale from 0 to 5 to provide exploratory priority ratings. The Urban domain received the highest exploratory weight (24.33%), followed by Social (22.60%), Environmental (20.85%), Economic (18.06%), and Political (14.16%). The highest-ranked indicators were schools, clinics, mosques, and playgrounds (4.34%); accessibility for people with disabilities (4.21%); and resident satisfaction with safety and identity (3.83%). The findings indicate differences between supply-side emphasis on infrastructure delivery, maintenance, and governance and demand-side emphasis on affordability, housing access, environmental conditions, and lived residential experience. The framework is intended as a context-sensitive, exploratory decision-support instrument that can complement established social value approaches in Kuwaiti residential development. Its practical performance and external validity require testing through independent application to completed or live residential projects. Full article

Lithium cobalt oxide (LiCoO${}_2$) is a widely used cathode material whose mechanical behavior under pressure is increasingly relevant to cell manufacturing and extreme-environment applications. Yet a coordinated understanding of how hydrostatic pressure simultaneously affects its structural, elastic, and vibrational properties has been lacking. Here, we employ first-principles DFT-GGA-PBE calculations to investigate the structure, elastic constants and moduli, and phonon band structure of $R\overline{3}m$ LiCoO${}_2$ under hydrostatic pressure from 0 to 50 GPa. The in-plane and interlayer lattice parameters contract anisotropically, with the c-axis showing greater compliance; our computed $c/a$ evolution reproduces the experimentally observed decreasing trend, lying systematically ∼2% below the convergent experimental datasets over the experimentally covered pressure range, with the deviation narrowing toward the highest experimentally covered pressures. All six independent pressure-corrected elastic constants increase monotonically and satisfy the Born stability criteria over the full pressure range. The polycrystalline bulk modulus more than doubles from 0 to 50 GPa, while the Young’s and shear moduli increase by 27–37%, with zero-pressure values ($B_{\mathrm{H}}=144.76$ GPa, $E_{\mathrm{H}}=214.65$ GPa, $G_{\mathrm{H}}=85.66$ GPa) in good agreement with pulse–echo and nanoindentation measurements. Phonon frequencies exhibit a systematic blueshift, with the highest-frequency optical modes hardening at an average rate of 0.102 THz/GPa, and remain real across the entire Brillouin zone, confirming the dynamical stability of the $R\overline{3}m$ phase. The correlated hardening of elastic moduli and phonon frequencies is consistent with pressure-induced bond shortening and the associated strengthening of the interatomic interactions, as evidenced by the monotonic contraction of the Co–O and Li–O bonds (by 4.1% and 9.7%, respectively, over the full pressure range). These results provide a quantitative benchmark for the mechanical behavior of layered oxide cathodes under pressure and offer a reference for related materials. Full article

It has been more than 30 years since the principle of Housing First (HF) was first conceptualized as a way of responding to people experiencing chronic homelessness in North America. It has been regarded by many as a trailblazing approach that focuses on the provision rapid housing responses for people experiencing homelessness with the option of accessing person-centered and flexible support services. The principle has come to underpin a wide variety of housing programs, most notably the Supportive Housing movement originating in New York City. The principle of HF continues to gather policy momentum and inform housing and homelessness policy and programs across the world. This paper addresses the question: How have four Western liberal democracies represented HF strategies within contemporary housing and homelessness policy documents? Using a qualitative analysis, this paper reports on a critical, interpretive and comparative international policy analysis of HF Programs across four major cities: Brisbane, Australia; New York City, USA; London, England and Stockholm, Sweden. These four locations were chosen for this study due to each nation being a Western liberal democracy and all espousing a policy commitment to the Housing First principle and associated strategies and programs. The findings from this research reveal that although support exists for Housing First principles, there is a wide variation in the way HF strategies feature in strategic housing and homelessness policy. The paper argues that despite good intentions, jurisdictions have largely taken an incrementalist approach to HF programs. The election of new administrations and recent policy announcements and settings provide hope for more concerted efforts in the scaling up of HF programs. Full article

In line with the International Marine Organisation (IMO) Net Zero 2050 strategy and its emphasis on improving shipboard energy efficiency, this project conducts a system analysis of a marine ICE exhaust gas, waste heat recovery system using ORC technology to quantify exergy efficiency and SFOC at varied ICE loads. A Wärtsilä 6L25 2 MW marine ICE in the diesel generation configuration is used for the case study and a commercial ORC system, selected based on calculated engine exhaust gas thermal energy. A high temperature heat exchanger design is calculated from first principles using the analytical NTU method, to give base geometry requirements to assess feasibility. Finally, exergy efficiency and combined ORC-DG system SFOC is quantified. Key results indicated exergy efficiency ranges from $24.5\%$ to $19.5\%$, with highest exergy efficiency being at 50% ICE load and lowest at 100% ICE load. Combined SFOC was shown to be lowest at 85% ICE load, representing a $\approx 7 \mathrm{g}/\mathrm{k}\mathrm{W}\mathrm{h}$ reduction from DG SFOC. The analysis indicated a usable ORC power output, ranging from $\approx 50 \mathrm{k}\mathrm{W}$ to $80 \mathrm{k}\mathrm{W}$. The main conclusions drawn are that research and ORC systems suitable for ICEs similar to the Wärtsilä 6L25 2 MW in the DG configuration are underreported, partially owing to a lack of suitable real-world data for research. Exergy efficiency and combined SFOC support the presented ORC-DG waste heat recovery system as an effective way to utilise exhaust gas waste heat that would otherwise be lost. However, when selecting and optimising an ORC system for waste heat recovery, designers should consider both real vessel operational profiles and lowest DG SFOC to maximise exergy recovery and efficiency with a high degree of accuracy. Similarly, optimising heat exchangers for actual DG operational profiles rather than theoretical 100% would avoid underutilisation and a larger physical heat exchanger footprint than necessary. This research should be considered as a first step system analysis of exhaust gas, waste heat recovery systems using ORC, as well as a contribution to critical research surrounding emissions reductions from shipping. Future studies should validate and expand upon the study by software modelling utilising full operational data from a suitable case study of vessels and manufacturers’ equipment data. Full article

In this study, first-principles simulations of inverse spinel Mg₂TiO₄ (MTO) and MTO:Mn⁴⁺ on the base of the tetragonal phase were performed within the linear combination of atomic orbitals (LCAO) approximation of density functional theory (DFT), as implemented in CRYSTAL23 computer code. The effect of Mn doping on the MTO band gap structure was studied for the first time. Lattice relaxation around Mn⁴⁺ ions upon substitution was considered. Two possible spin configurations of the Mn⁴⁺ ion (3d³) in MTO:Mn⁴⁺ (total spin of system S = 3/2 and 1/2) were considered in the framework of the unrestricted (open shell) DFT-LCAO calculations. The structural, electronic, vibrational, dielectric and elastic properties of materials were investigated, compared and discussed. It has been shown that dopant atoms create new defect states within the band gap and modify the conduction band and the valence band, which is one of the most important results in the present study. The effect of isotopic substitution on the vibrational properties was analyzed. Based on the calculated elastic moduli, the Debye temperature for MTO was estimated. This study provides a basis for the assessment of the optical and luminescent properties of the doped material and its use in LED applications. Full article

Repeated molecular sampling of the distal airways is constrained by the invasive nature of bronchoalveolar lavage (BAL), limiting its use in healthy control populations, longitudinal studies, clinical trials and occupational screening. Particles in exhaled air (PExA) sampling offers a non-invasive approach to distal-airway sampling, although whether it captures the same proteins and relative protein abundance as BAL has not been established. We performed the first proof-of-principle high-dimensional proteomic comparison of matched BAL and PExA samples collected from three individuals with silicosis using the SomaScan 11K platform. Within individuals, PExA and BAL shared a substantial subset of detectable proteins and showed similar cross-protein signal patterns, with Pearson correlation coefficients ranging from 0.48 to 0.71. Analytes recurrently detected across all three PExA samples were strongly enriched among those consistently detected in BAL and included pulmonary surfactant proteins and mediators associated with epithelial injury, alveolar macrophage function, inflammation and fibrosis. The PExA findings also showed substantial overlap with an independent published PExA-only proteomic dataset. These proof-of-principle findings show that non-invasive PExA sampling can capture a biologically meaningful subset of the matched BAL proteome. PExA may therefore offer a practical approach for repeated molecular profiling of the distal airways and warrants further evaluation for respiratory biomarker discovery and disease monitoring. Full article

Eight-wheel drive vehicles have many areas of use, such as military, logistics, firefighting, and disaster response. One of the key design requirements of an 8 × 8 vehicle is to achieve low turning radius at low speeds, without loss of stability and handling at high speeds. In this study, an 8 m turning radius is taken as a preliminary design objective of a 24-ton vehicle, and best handling performance is achieved for high speeds using simulations and the Taguchi Method. While achieving the 8 m turning radius, calculations are based on Akerman’s principle to calculate the turning angles of each wheel. The bicycle model was derived using motion equations, then implemented in MATLAB/Simulink (version 2023b) model to predict the slip angle for six degrees of sinusoidal steering input and a longitudinal speed of 72 kph. The effects of design parameters such as steering configuration and axle distances on slip and steering angle were investigated by design of experiments. With the help of ANOVA analysis performed using Minitab software (version 19), the relationship and optimized solutions were achieved to satisfy both minimum slip angle and steering stability. Minitab optimizer results conclude that Configuration 3 with L1 = 2.45 m, L2 = L3 = 0.8 m, and L4 = 2.3 m axle distances achieved a mean slip of 2.54 × 10⁻² radians delay during the sinusoidal maneuver of 4.19 × 10⁻³ radians at 20 m/s forward speed. Although the optimum solution is achieved with the third configuration, there is not a common solution to achieve both the lowest slip and the highest stability with the same set of design parameters. Finally, a CAD model of the first two axles is established using the software Solidworks (version 2025). A kinematics model including pitman arm, idle arm, and steering rods is designed and virtually validated using ADAMS/View (version 2025.1) multibody dynamics software. Full article

Organic supercapacitors (OSCs) suffer from sluggish Li⁺ desolvation and ion diffusion kinetics, limiting their electrochemical performance and practical application. Heteroatom doping is a valid strategy to improve the capacitive properties of carbon electrode materials. Herein, density functional theory (DFT) first-principles calculations were adopted to systematically investigate and compare the effects of equal-concentration N and P doping on the Li⁺ desolvation behavior, capacitance performance, and ion diffusion kinetics of single-walled carbon nanotubes (SWCNTs) in acetonitrile-based electrolytes. The results show that N doping maintains the [Li(AN)]⁺ critical desolvation size (5.91 Å) of pristine SWCNTs, while P doping increases this size to 6.11 Å. Benefiting from the optimized desolvation behavior, P-doped SWCNTs achieve a maximum relative capacitance 1.9 times that of pristine SWCNTs, outperforming N-doped SWCNTs (1.3 times). Moreover, P doping significantly reduces the [Li(AN)]⁺ diffusion barrier to 0.99 eV, much lower than that of pristine and N-doped SWCNTs, thereby accelerating ion migration. Electronic structure analysis confirms that heteroatom doping weakens electron localization and C-heteroatom covalent bonding, and the weaker P-C bonding further accounts for the superior performance of P-doped SWCNTs. This study clarifies the intrinsic regulatory mechanism of N/P doping on Li⁺ desolvation and electrochemical performance of SWCNTs, providing a theoretical guideline for the design of high-performance carbon-based electrodes for OSCs. Full article

Wide-bandgap indium-oxide thermoelectric materials face a strong electrical–thermal transport trade-off and low structural reliability, limiting their thermoelectric efficiency and practical deployment on welding robots. To overcome these bottlenecks, gradient Na-doped In₂O₃ ceramics are fabricated by mechanical alloying combined with spark plasma sintering. A dual-functional modulation mechanism via monovalent alkali-metal doping is proposed to decouple thermoelectric performance. Unlike conventional high-valence doping that degrades the Seebeck coefficient and raises thermal conductivity, moderate Na substitution introduces shallow acceptor states, oxygen vacancies, or other compensating defects inside the bandgap, precisely tuning the Fermi level and carrier concentration within the optimal transport window. This mild electronic-structure reconstruction balances conductivity and Seebeck coefficient, boosting the power factor without carrier overflow or saturation. The ionic-size mismatch between Na⁺ and In³⁺ generates controllable point defects and uniform lattice strain, scattering multi-frequency phonons to suppress lattice thermal conductivity while avoiding excessive electronic thermal conductivity. Na doping also improves lattice bonding and thermomechanical properties, enhancing Vickers hardness to offset doping-induced mechanical deterioration. Supported by first-principles calculations, this work reveals the mechanism of shallow-level electronic modulation coupled with lattice-strain engineering. The optimized sample delivers good medium-temperature conversion efficiency and structural stability. This study achieves simultaneous improvement in thermoelectric and mechanical properties, fills the research gap for alkali-metal-modified In₂O₃, and offers theoretical guidance for high-performance oxide thermoelectric material design. Full article

This study contends that the dialogic structure of “question” (wen 問) and “response” (ying 應) is not only a description of the procedure of divination, but also the logic through which the Yijing constructs the human–divine relation. There are two core questions: First, how does this dialogical structure generate a religious communicative model that presupposes the finitude of the human questioner and the transcendence of the responding divine? Second, how does this same structure enable a shift in divination from a ritual technique for resolving doubt to a discipline for existential self-realization? This study, by drawing on the Yijing text and later commentaries, argues that “questioning” is not limited to a cognitive request for information but also an existential opening of the finite self to the transcendent, conditioned by “sincerity” (cheng 誠) and impelled by the recognition of human limitation. The “response” is unfolded in two progressively deeper registers: “image response” (xiang ying 象應), which presents a field of “image” meaning that must be interpreted, and “response of bestowal” (ming ying 命應), which requires the diviner to internalize Heaven’s generative bestowal through fully comprehending and exhausting the principles (qiong li 窮理) and realizing his own “nature” (jin xing 盡性). The cosmological principle of “communion through resonance” (gan 感), based on the common qi 氣 of humanity and Heaven, integrates “questions” and “responses”. The path from question to answer is thus the path from doubt to self-transcendence, where divination fulfills itself not in prediction but in the harmonizing of human virtue with the cosmic rhythm. The contribution of this study is to show how the religious act of “questioning” becomes a discipline of existential realization, and how the structure of “question” and “response” holds the key to understanding the transformation of the Yijing from a manual of divination into a project of human realization and transcendence. Full article

Hydroxyapatite (HAp) possesses exceptional compositional flexibility, allowing for extensive cationic, anionic, and coupled substitutions that can modify its structural, mechanical, electronic, magnetic, catalytic, and biological properties. However, experimental identification of dopant locations and charge-compensation mechanisms remains challenging, particularly in nanocrystalline, calcium-deficient, and multiphase materials. This review evaluates first-principles studies of ion-substituted HAp, with particular emphasis on substitution-site preferences, defect association, charge compensation, thermodynamic stability, configurational effects, surfaces, hydration, and comparison with experimental observables. Unlike earlier reviews that primarily catalogued individual dopants and their calculated effects, the present work critically examines the methodological and defect-chemical assumptions underlying reported substitution mechanisms, including charge compensation, configurational sampling, chemical-potential definitions, hydration, finite-temperature effects, and experimental validation. The literature demonstrates that dopant site preference is not an intrinsic and concentration-independent property of an element. Instead, it depends on supercell size, dopant concentration, hydroxyl ordering, oxidation and spin states, compensating defects, chemical potentials, hydration, temperature, and the presence of other impurities. Many apparent discrepancies between studies arise from small simulation cells, incomplete configurational sampling, inconsistent formation-energy definitions, or calculations performed for assumed compositions without explicit charge compensation. The strongest structural assignments combine defect energetics with directly calculated spectroscopic parameters. Future predictive models should treat substituted HAp as a condition-dependent ensemble of interacting defects and integrate large-scale configurational sampling, finite-temperature methods, hydrated surfaces, machine learning, and advanced spectroscopic validation. Full article

Hybrid rural–urban environments present growing challenges for architecture and design because they require ecological, cultural, and spatial values to be integrated within coherent design solutions. This study proposes a qualitative framework for identifying sustainability aesthetics archetypes that can support the interpretation and design of such hybrid environments through the integration of accessible artificial intelligence (AI) tools and author-based qualitative analysis. The research is based on a design experiment conducted with first-year Industrial Design Engineering students at Kaunas University of Technology during 2024–2025, resulting in a dataset of 43 modular spatial systems. Photographs of the design outcomes were analysed using user-friendly AI tools to generate image descriptions, semantic tags, colour palettes, and AI-assisted visual interpretations, which were combined with researcher observations in a triangulated qualitative framework. Comparative cross-case analysis identified six recurring sustainability aesthetics archetypes: living organism, habitat, geological harmony, modular ecosystem, cultivated landscape, and biomorphic artefact. Together, these archetypes provide a conceptual vocabulary for exploring how sustainability-related aesthetic principles might inform buildings, public spaces, and hybrid rural–urban environments. Beyond the identified archetypes, the study illustrates how accessible AI-assisted visual analysis can support the interpretation of implicit sustainability-related aesthetic patterns and complement researchers’ qualitative interpretation in architectural and design research. Full article

Differentiated instruction has been proposed as an effective approach for addressing learner diversity and enhancing learning outcomes. The present study investigated the effects of a differentiated instructional intervention, informed by principles of cognitive psychology, Cognitive Load Theory, and educational neuroscience, on cognitive performance, learning engagement, and perceived cognitive load among vocational education students. A quasi-experimental design was implemented with 57 students enrolled in the Pharmacy Assistant specialty program of the Greek Public Employment Service Vocational Education Schools (EPAS DYPA). Two first-year and two second-year classes participated in both traditional and differentiated instructional sessions. Cognitive performance, learning engagement, and cognitive load were assessed through quizzes, application exercises, questionnaires, and rating scales. The findings indicated no statistically significant differences between instructional approaches among first-year students. In contrast, significant differences were observed primarily among second-year students, who demonstrated higher cognitive performance and learning engagement following differentiated instruction, along with a reduction in perceived cognitive load; the strongest effects were observed in application exercises, suggesting improved knowledge transfer and practical application. Most students expressed a preference for the differentiated instructional approach. Overall, the findings highlight the potential value of differentiated instructional approaches in supporting learning processes within vocational education settings. Full article

In our earlier methodology paper, we introduced a hierarchical framework combining graph compression, Diffusion Convolutional Recurrent Neural Networks (DCRNNs), and Multi-Agent Reinforcement Learning (MARL) to approximate Bellman’s optimality principle for real-time energy system control, validated using Palm Springs, California weather data. This extension paper addresses three critical advances. First, we provide a rigorous theoretical proof demonstrating that the DCRNN’s Markovian reduction of strongly path-dependent dynamics yields a bounded approximation error, with the error decaying exponentially in the mixing time of the underlying graph diffusion process. Second, we extend the framework to diverse weather regimes—from stable Mediterranean climates (San Diego) to highly variable marine west coast (Seattle), monsoon (Mumbai), and typhoon-prone regions (Hong Kong)—quantifying how weather-induced path dependence affects the required hidden state dimension and forecasting accuracy. We present comprehensive Leave-One-Out Cross-Validation (LOOCV) results across six cities, demonstrating consistent generalization with R² drops of less than 0.1% under out-of-sample testing. A controlled baseline comparison under matched training protocols shows that the graph-free GRU achieves comparable or higher R² on the one-step prediction task, which we attribute to the near-cumulative structure of the target and the small evaluation graph. We frame the DCRNN’s contribution around its theoretical guarantee and its potential advantage on larger graphs and longer horizons. We also characterize conditions under which the model expects to fail, specifically when weather stochasticity violates the geometric mixing assumption or when the effective temporal correlation length exceeds the GRU’s memory capacity. Third, we outline physics-informed enhancements that are proposed as future development: CFD-integrated loss functions, differentiable Model Predictive Control (MPC) heads, and a modular design enabling alternative turbine configurations. We also propose a standardized rooftop solar thermal deployment architecture with 200 m × 100 m, 100 m × 100 m, and 100 m × 50 m modules designed for data center footprints with pre-allocated HVAC space. We conclude with a stage-gated validation roadmap progressing from unit tests to hardware-in-the-loop simulation to full-scale FEED-site deployment. The completed contributions of this paper are the theorem, its empirical assumption verification, the multi-climate LOOCV study, the matched-protocol baseline comparison, and the sensor-failure robustness analysis. The remaining components are described as proposed extensions. Full article