Search Results (436)

Background/Objectives: The aim of the present investigation was to validate the diagnostic performance of the AI-based dental cloud software Diagnocat^® AIS (Version 1.0 (UDI: 860010268018), DGNCT LLC, Miami, FL, USA) regarding the detection possibilities of seven different endodontic findings on cone-beam computed tomography (CBCT) against a multi-rater consensus reference standard, and to characterize its calibration, threshold-optimized performance and clinical utility. Methods: 358 root-canal-treated teeth from 167 CBCT scans (167 patients) were retrospectively evaluated at a single private dental practice. From initially included 383 root-canal-treated teeth from 177 patients, 358 (93.5%) were recognized by the AI tool and entered the primary analysis. Two experienced dentists with a clinical focus on endodontics independently graded each tooth and disagreements were adjudicated by a senior expert. Seven different endodontic findings were evaluated: (i) apical (periapical) lesion; (ii) short root-canal filling (apical filling end >2 mm short of the radiographic apex); (iii) voids/lacunae in the root-canal filling; (iv) missed (un-instrumented/un-filled) canal; (v) overfilled root-canal filling (apical extrusion); (vi) apicoectomy (resected root apex with or without retrograde filling); and (vii) coronal restoration with a full-coverage crown. Diagnocat^® output was binarized at the manufacturer-fixed 0.50 probability threshold; sensitivity, specificity, predictive values, accuracy, area under the curve AUC (ROC), Cohen κ and Gwet AC1 were computed with 95% cluster-bootstrap confidence intervals (cluster = scan). Threshold optimization, probability calibration, GEE-based subgroup analyses, and decision-curve analysis were pre-specified. Results: Diagnostic performance varied by finding. AUCs were 0.984 for missed canal, 0.917 for overfilled root canal, 0.902 for short root filling, 0.893 for crown, 0.864 for apical lesion, 0.857 for apicoectomy and 0.761 for voids in the root filling. Apical-lesion sensitivity rose from 33.6% for sub-millimeter lesions to ≥80% for lesion measuring 1–5 mm. Re-tuning the decision threshold raised missed-canal sensitivity from 69.6% to 97.5%. Decision-curve analysis confirmed positive benefits for missed canal and root-filling-quality findings. Conclusions: The AI tool Diagnocat^® can be recommended as a focused screening adjunct in CBCT-based endodontic interpretation for missed canals, crowns, and gross root-filling-quality flaws. Sub-millimeter apical lesions and several less common findings (resorption, instrument fragment, retrograde filling) remain outside the reliable performance envelope of the current platform. Full article

This study presents a computational and experimental aerodynamic characterisation of a full-scale 5.5 m diameter, six-sail horizontal-axis windmill of the traditional Cretan Lasithi type, equipped with flexible woven polyester sails that act as a passive load-control mechanism. Seventeen operating points spanning wind speeds of 2.3–18.3 m/s were simulated in OpenFOAM using a transient sliding-mesh Arbitrary Mesh Interface formulation with the k–ω SST turbulence closure on a 2.3 million cell grid, selected on the basis of a four-level grid convergence study. CFD simulations identify three distinct aerodynamic regimes: a drag-dominated high-TSR regime (λ > 2.1), a mixed lift–drag working range with peak loading near λ ≈ 1.4–1.5, and a deep-stall regime in which boundary-layer separation propagates from root to tip as λ falls below 1.0. Field measurements conducted at the Energy Systems Synthesis Lab of the Hellenic Mediterranean University in compliance with IEC 61400-12-1:2005(E) confirm that rotor speed stabilises passively at 55–58 RPM above 13 m/s without any active control mechanism; CFD predictions agree with measured power output within 8–12% across the 2–13 m/s attached-flow envelope. The combined evidence indicates that passive overspeed self-regulation is driven by aeroelastic sail deformation, reducing effective disc solidity at high wind speeds, a mechanism that rigid-geometry CFD correctly identifies in trend but cannot quantify in magnitude. The primary limitation of the present work is the rigid-sail assumption of the CFD model, which requires a two-way coupled fluid–structure interaction extension as a future step. Full article

While double-layer insulation structures are widely adopted, their thermal performance is critically dependent on the thermophysical behavior of the interstitial air cavity, a variable often oversimplified in current design practices. This article moves beyond generic material descriptions to investigate the specific mechanism of heat transfer transition within sealed air gaps sandwiched between graphite polystyrene boards. The innovation of this experiment lies in the rigorous isolation of air gap thickness as the primary independent variable within a 1 × 1 × 1 m closed building model, instrumented with high-precision GPRS temperature and humidity sensors to capture real-time thermal gradients under the authentic climate conditions of Anyang, Henan. The results demonstrate a non-monotonic relationship between gap thickness and effective thermal resistance, governed by the competition between molecular conduction and buoyancy-driven natural convection. Specifically, the data validates that a 20 mm air gap represents the statistically significant optimum, thereby maximizing insulation efficiency while minimizing radiative heat loss. Using this optimized structure reduces steady-state heat flux compared to monolithic equivalents and aligns with the energy conservation target. Unlike previous studies limited by simulation assumptions or short-term testing, this research provides empirically verified, long-term field data that bridges the gap between theoretical fluid dynamics and practical building envelope engineering. These findings offer a robust, physics-based reference for optimizing double-layer insulation systems in the Central Plains, directly supporting the low-carbon retrofitting of existing building stocks. Full article

In this study, the influence of thermal loading in a supersonic flight environment on the mechanical stiffness of elastic structures and the corresponding aeroelastic stability limits is investigated analytically. Recognizing that elevated temperatures inherently alter constituent elastic properties, a temperature-dependent continuous elasticity framework is incorporated directly into the governing differential operators of the structural domain. The macro-mechanical behavior of representative panel- and wing-type elements is modeled utilizing the Euler–Bernoulli beam formulation, while high-speed supersonic aerodynamic effects are represented through linearized first-order piston theory. The continuous spatial displacement fields are discretized by means of a modal expansion, and the coupled aeroelastic system is subsequently transformed into a finite set of dynamic state-space equations using the Ritz–Galerkin truncation method. The numerical and analytical outputs demonstrate that aerothermal softening not only induces continuous erosion in the material stiffness but also directly modulates the aeroelastic pole trajectories, thereby prematurely contracting the safe supersonic flight envelope. The primary novelty of the proposed framework lies in the derivation of explicit analytical expressions that directly map temperature-dependent stiffness variations onto supersonic aeroelastic instability boundaries. Because this approach is formulated in a generalized analytical form, it can be applied across diverse material systems, geometric profiles, and thermal conditions with reduced computational overhead compared to full fluid–structure interaction solvers, thereby providing a theoretical basis for preliminary stability assessment of supersonic aerospace configurations operating under high-temperature conditions. Full article

The cell envelope of Gram-positive bacteria is a primary target of host immune defenses and antibiotics, and its stability is influenced by environmental factors, including the availability of the divalent cations Mg²⁺ and Ca²⁺. Alanine also plays a critical role in cell envelope integrity, contributing to peptidoglycan cross-linking, D-alanine modification of teichoic acids, and protein synthesis. However, how these factors functionally interact to maintain envelope stability in S. aureus remains unclear. Here, we demonstrate that growth of S. aureus under Mg²⁺-limited and Ca²⁺-limited conditions requires increased alanine uptake mediated by the transporter AapA. Loss of AapA results in increased cell lysis and impaired growth under cation-limited conditions, and removing alanine from the growth medium phenocopies these aapA mutant defects. Alanine limitation increases susceptibility to the detergent Triton X-100 and the membrane-targeting antibiotic daptomycin, consistent with defects in envelope stability. Furthermore, aapA function contributes to bacterial fitness in insect and murine infection models. Together, these findings indicate that Mg²⁺, Ca²⁺, and alanine play overlapping roles in stabilizing the S. aureus cell envelope, pointing to AapA as a target that may leveraged to enhance antimicrobial efficacy. Full article

Healthcare facilities are among the most energy-intensive public infrastructures due to their continuous operations, complex systems, and critical service requirements. In this context, Energy Performance Contracts (EPCs) have gained increasing attention as a strategic tool for enhancing energy efficiency and sustainability in healthcare facilities. This paper investigates the potential and implementation of EPCs in the hospital sector, with a particular focus on their integration within Public–Private Partnership (PPP) frameworks. The study addresses that gap through a cross-case analysis of fourteen hospital EPC projects implemented in Italy, the United Kingdom, the Nordic countries and Central-Eastern Europe, mapping their technical scope against a three-family taxonomy (envelope, plant systems, regulation and monitoring) and benchmarking their energy and economic performance. All figures reported derive from project documentation and contractual monitoring records. The results show that envelope-led configurations deliver the deepest reductions in primary and final energy consumption (up to 50% on the baseline), while plant-side measures, and trigeneration in particular, generate the largest absolute CO₂ savings (from approximately 500 to 17,000 tCO₂eq/yr); lighting, and building management systems (BMS) retrofits, although ubiquitous, account for a 20–25% band when deployed in isolation. The findings reframe EPCs as a configurable contract for decarbonization in healthcare environments and offer practitioners a reading grid for scoping future hospital retrofits under this framework. Full article

Rammed earth has long been recognised for its economic, environmental, and social advantages, and it is increasingly considered a sustainable alternative within the construction industry. Its primary benefit lies in the use of local soils, thereby minimising environmental impacts associated with material transport. At present, the assessment of soil suitability relies primarily on particle size distribution (PSD) envelopes or the maximum dry density achieved in compaction tests. Although the mechanical performance of unstabilised rammed earth (URE)—most notably its unconfined compressive strength (UCS)—depends heavily on soil clay content due to clay’s role as a natural binder, clay-rich soils are often excluded by existing criteria, despite reports of acceptable strength in such materials. In this study, URE specimens were prepared from a single local soil by systematically varying its clay fraction. The optimum moisture content (OMC) of all mixtures was determined, and all specimens were cured under controlled conditions for 28 days before being subjected to UCS testing. One-way ANOVA confirmed a statistically significant influence of clay content on UCS, and a logarithmic regression model was developed and benchmarked against published data. The results indicate that, under the controlled material and curing conditions investigated, the clay fraction can serve as a practical first-order indicator of compressive strength and related physical parameters in URE, although its predictive capacity must be interpreted together with mineralogy, moisture state, compaction conditions, and soil fabric. Full article

The environmental performance of residential buildings depends not only on envelope quality but also on the choice of heating, domestic hot water, and ventilation systems. This study presents a comparative assessment of eight technology packages for a reference single-family house located in Warsaw, Poland, using a harmonised framework under Polish EPC calculation assumptions, with identical building parameters, system boundaries, and functional assumptions for all variants. Operational performance was evaluated using Energy Performance Certificate indicators, including useful energy, final energy, non-renewable primary energy, operational CO₂ emissions, and the share of renewable energy sources. In addition, a comparative 50-year scenario of operational CO₂ emissions was developed, and a screening life-cycle carbon assessment of the reference building fabric and major building components was performed to provide a material and construction-related carbon context for the operational comparison. The embodied impacts of package-specific technical systems were excluded from the LCA scope. The results showed that fossil-dominated packages generated the highest primary energy demand and operational emissions, whereas renewable-supported and hybrid configurations substantially improved environmental performance. Under the adopted EPC-based accounting assumptions, the fully renewable packages achieved the lowest operational indicators; however, these variants should be interpreted as upper-bound theoretical scenarios rather than as demonstrated real-life zero-emission solutions. Therefore, they were not used as the main basis for the practical ranking. Among the practically comparable mixed configurations, the most favourable operational results were obtained for renewable-supported heat-pump-based packages. The screening life-cycle assessment indicated that a substantial part of the total environmental burden was associated with the product and construction stages of the reference building. The results confirm that the interpretation of residential technical packages depends strongly on the adopted assessment perspective and that operational indicators should be considered together with at least a screening-level carbon context for the building fabric. According to the calculation results, the EP value ranges from 0 to 90.8 kWh/(m²·year), depending on the technology package. Full article

The building shape coefficient is an important metric in building design and energy analysis for describing the geometric compactness of a building. However, the conventional shape coefficient neglects the beneficial contribution of transparent building envelopes in utilizing solar radiation. To address this limitation, this study proposes a novel indicator, the building shape energy-saving coefficient (E), which accounts for the thermal performance differences between transparent and non-transparent building envelopes. A key intermediate parameter in the development of this indicator is the transparent envelope equivalent coefficient (C_i). Numerical simulation results indicate that climate conditions and building orientation are the primary factors influencing C_i. Based on these results, reference C_i values for different orientations of linear buildings in typical cities are provided. Subsequently, the corresponding E values are calculated, and the correlations between E, the traditional shape coefficient, and building air conditioning energy consumption are systematically compared. The results show that the coefficient of determination between E and air conditioning energy consumption exceeds 0.80, significantly higher than that between the traditional shape coefficient and energy consumption, demonstrating the improved predictive capability of the proposed indicator. Full article

Reliable short-term hydropower forecasting is essential for dispatch planning and early electricity procurement in snowmelt-influenced power systems. This study develops a leak-free operational forecasting framework using quality-controlled hourly generation and hydro-meteorological records from eight hydropower plants in Kazakhstan. Two tasks are addressed: deterministic multi-step forecasting for D+1–D+7 and uncertainty-aware envelope forecasting for D+8–D+14 using MIN and Q90 targets. The benchmark uses Persistence as the primary baseline, against which RIDGE, SARIMAX, Random Forest, HistGradientBoosting, MLP, and LSTM are compared using Nash–Sutcliffe efficiency (NSE), root mean squared error (RMSE), and mean absolute error (MAE). For D+1–D+7, the results reveal strong cross-station heterogeneity and the expected decline in skill with increasing lead time. In the aggregated comparison, SARIMAX achieves the highest mean NSE at D+1 (0.903), while RIDGE becomes strongest by D+7 (0.625), both outperforming Persistence (0.534 at D+7). At the station level, SARIMAX performs best for Kapch, Kask, Moin, Bukh, and Ustk, RIDGE is best for Shar and Lenin, and LSTM is best for Shulb. The strongest stations, Kapch and Kask, reach mean NSE values of 0.941 and 0.933, respectively, whereas Ustk and Bukh remain the most difficult cases. A central methodological contribution is a flood-sensitive switched hybrid strategy for Ust-Kamenogorsk based on an observed-generation high-flow window selected by a regime-score procedure. This strategy improves robustness at medium lead times: for SARIMAX, NSE increases from 0.587 to 0.739 at D+2 and from 0.161 to 0.559 at D+7, while for RIDGE, NSE increases from 0.549 to 0.701 at D+2 and from 0.109 to 0.435 at D+7, together with substantial RMSE and MAE reductions. For D+8–D+14, envelope forecasting remains informative, but model ranking becomes target-dependent: SARIMAX and RIDGE provide the strongest mean performance for MIN (0.664 and 0.658), whereas LSTM and RIDGE are strongest for Q90 (0.746 and 0.743). Overall, the results show that hydropower forecasting in Kazakhstan is best approached as a station-wise, regime-aware, and horizon-specific problem. Full article

The excavation of deep shafts using Vertical Shaft Sinking Machine (VSM) technology in stratified soft soils involves complex soil-structure interaction (SSI) mechanisms that are often oversimplified by conventional numerical approaches. This study develops a robust three-dimensional numerical framework to investigate ground deformation induced by VSM operations, explicitly incorporating the phased construction sequence, segmental lining installation, and site-specific stratigraphy. The model is calibrated and validated against high-resolution field monitoring data, employing a prediction envelope approach and statistical performance metrics (RMSE and $R^2$). The results suggest that ground response during VSM excavation is predominantly stiffness-controlled under the investigated conditions. Mobilized shear stresses remain significantly below the available soil capacity, indicating that deformation under serviceability conditions is driven by progressive strain accumulation. Horizontal displacement profiles suggest a relatively stable depth of influence, indicating that the excavation process amplifies deformations within a pre-established domain without significant deep-seated propagation. Sensitivity analyses indicate soil stiffness modules ($E_{50},E_{oed},E_{ur})$ and the SSI interface factor ($R_{inter}$) as the primary drivers of deformation magnitude. Furthermore, stratigraphic contrasts specifically clay-sand sequences, act as a mechanical filter, concentrating strains in soft layers while limiting vertical propagation through stiffer strata. The proposed framework provides a mechanically coherent basis for serviceability-oriented design, deformation prediction, and risk-mitigation strategies for mechanized shafts in saturated soft ground. Full article

The construction sector accounts for approximately 36% of global final energy consumption and close to 40% of total CO₂ emissions, making it a primary target of international climate policy. Despite this growing attention, the indigenous building traditions of the Ecuadorian Andes remain virtually absent from the international scientific literature on vernacular sustainability. This study presents a systematic field documentation and bioclimatic assessment of vernacular bahareque dwellings in the Kichwa-Saraguro community of Ilincho, canton of Saraguro, province of Loja, Ecuador (2700 m a.s.l.). A field survey of 30 dwellings identified five morphological typologies—I-1P, I-2P, 2B, L, and C—with typology C, a compact C-shaped block with a three-sided portal, accounting for 53.3% of the sample. A structured multi-criteria framework of 48 bioclimatic indicators distributed across eight categories, adapted to the cold-temperate mountain climate of the study area, was applied to quantify each typology’s bioclimatic performance. All typologies exceeded 75% overall compliance on the global Bioclimatic Performance Index (BPI), with typology C achieving the highest value (88.5%). Categories F (Materials and construction) and H (Cultural and social aspects) scored 100% across all typologies, reflecting system-level properties of the bahareque constructive system rather than morphological differences between typological variants; a supplementary morphological BPI restricted to Categories A–E and G is reported. An exploratory, uncalibrated energy simulation of typology C provided indicative evidence consistent with the expected thermal behavior of a high-thermal-mass bahareque envelope, with simulated minimum temperatures in the sleeping area within the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 55-2013 comfort range (T-min 18.80 °C). Collectively, these findings contribute quantified bioclimatic documentation of vernacular bahareque architecture in Ilincho, identifying attributes—encompassing solar control, spatial compactness, high-thermal-mass envelope performance, and use of locally sourced low-embodied-energy materials—that may inform sustainable rural housing discussions in the Ecuadorian Andes and comparable high-altitude mountain contexts. Its documentation in the indexed scientific literature constitutes a step toward recognizing this constructive heritage as a practical resource for low-carbon building policy. Full article

The indoor environmental quality of primary and secondary school classrooms is crucial for students’ health and learning efficiency, yet enhancing comfort often leads to high energy consumption. Efficiently balancing the complex relationship between daylighting, visual comfort, and energy consumption during the early design stage presents a significant challenge for architects. To address the design optimization of standard classrooms in primary and secondary schools in the cold region of Zhengzhou, this paper proposes an efficient multi-objective optimization method based on metamodels. This method integrates physical performance simulation (EnergyPlus and Radiance), Latin Hypercube Sampling (LHS), an artificial neural network (ANN) metamodel, and the Non-Dominated Sorting Genetic Algorithm II (NSGA-II). Using Useful Daylight Illuminance (UDI), Discomfort Glare Index (DGI), and Cooling Energy Use Intensity (cEUI) as optimization objectives, ten design parameters, including classroom spatial form and envelope structure, were optimized. The aim is to replace time-consuming traditional simulation calculations and rapidly generate a Pareto optimal solution set. A case study of a typical south-facing classroom in Zhengzhou demonstrates that this method can substantially improve daylighting performance while moderately reducing cooling energy. Compared to the baseline model, the optimized schemes show an average increase in UDI of 42.9% (maximum 50.5%), an average reduction in DGI of 8.4% (maximum 9.6%), and an average reduction in cEUI of 4.7% (maximum 7.7%). Because the study focuses on summer cooling energy only, the reported cEUI improvement should not be interpreted as an annual energy reduction. Through K-means clustering and sensitivity analysis, the study further identifies different design strategies from the Pareto solution set and clarifies the key design variables affecting each performance indicator. This provides an evidence-based reference and preliminary design guidelines for the early-stage design of primary and secondary school classrooms in the region. Full article

To this day, the etiology of multiple sclerosis has yet to be fully comprehended by the scientific community. However, the knowledge on mechanisms leading to the development of this neurodegenerative autoimmune disorder increases daily, along with the development of new disease-modifying treatments. A correlation between Epstein–Barr Virus infection and the disease incidence has recently shed light on possible innovative antiviral therapies. Here, we review the literature on Human Endogenous Retroviral sequences as emerging actors for the impairment of remyelination as a major challenge in disease progression. Our primary focus is the HERV-W envelope protein, which has been found at elevated levels in individuals affected by this condition and is suggested here as a potential therapeutic target. We then continue analyzing the clinical cases where antiretroviral drugs have been tested to treat multiple sclerosis patients and, from successes and failures, we finally narrow down our therapeutic hypothesis to the administration of Nucleoside-analog Reverse Transcriptase Inhibitors to target the HERV-W envelope protein, possibly leading to remyelination and significantly improving the condition of those affected by the disease. The main purpose of this review is to present a rationale for the therapeutic potential of this drug class and offer a new perspective for therapeutic options against multiple sclerosis. Full article

This paper studies a realization-theoretic problem inside the standard Lorentz-covariant Fourier-dual framework on $L^2\left({\mathbb{R}}^{3,1}\right)$: whether position-space and momentum-space geometric translations can be placed on equal structural footing without leaving the ordinary X- and K-polarized realizations. Working on the common Schwartz core $\mathcal{S}\left({\mathbb{R}}^{3,1}\right)$, we first isolate a Fourier-compatibility obstruction: Fourier transform exchanges geometric translations with character actions, while the Poincaré algebra contains at most one Lorentz-covariant abelian translation ideal. The main result is that, within the resulting Fourier-compatible realization class, the minimal operator-generated Lie algebra is the Lorentz–Heisenberg algebra. We then determine the full center of its universal enveloping algebra, derive the normalized Lorentz-bivector invariants, orbit data, and connected stabilizers in nondegenerate sectors, and show that the orbit variable is a normalized Lorentz bivector rather than a momentum vector. Finally, for fixed spectral elements in the dual translation sectors, we derive the associated scalar, Dirac, and vector equations in position and momentum space and show that, in the regular polarized realizations, the represented Heisenberg sector induces dual local abelian phase groups, compatible covariant derivatives, curvatures, and primary Dirac–Maxwell systems. Full article