Search Results (230)

The variation in the maximum usable frequency (MUF) during geomagnetic disturbances is a key parameter for high-frequency (HF) radio communications. This study investigates MUF variability and related ionospheric parameters during the first geomagnetic superstorm of solar cycle 24, on 17 March 2015 (the Saint Patrick’s Day storm). Using Digisondes at Sao Luis (equatorial) and Campo Grande (low-latitude, near the southern crest of the Equatorial Ionization Anomaly), we analyzed storm-time changes in the F region. During the main phase, two episodes of eastward Prompt Penetration Electric Fields produced rapid uplifts of the F2-layer peak height at São Luis, reaching altitudes up to 520 km, accompanied by MUF decreases of approximately 25% relative to quiet-day values. In contrast, Campo Grande exhibited a more subdued response, with MUF deviations generally remaining within 15–20% of quiet-time conditions. During the recovery phase, the likely occurrence of a westward disturbance dynamo electric field was inferred from suppression of the Pre-Reversal Enhancement and decreased F-layer heights at São Luis. Comparative analysis highlights distinct regional responses: São Luis showed strong storm-time deviations, while Campo Grande remained comparatively stable under the impacts of Equatorial Ionization Anomaly effects. These results provide quantitative evidence of localized geomagnetic storm impacts on MUF in the Brazilian sector, offering insights that may improve space weather monitoring and HF propagation forecasting. Full article

We investigate the $\alpha$ and $\beta$ effects in a rotating spherical plasma system relevant to astrophysical contexts. In particular, we focus on how kinetic and magnetic (current) helicities influence the magnetic diffusivity $\beta$. These coefficients were modeled using three complementary theoretical approaches. Direct numerical simulation (DNS) data (large-scale magnetic field $\overline{\mathbf{B}}$, turbulent velocity $\mathbf{u}$, and turbulent magnetic field $\mathbf{b}$) were then used to obtain the actual values of ${\alpha }_{\mathrm{EM}-\mathrm{HM}}$, ${\beta }_{\mathrm{EM}-\mathrm{HM}}$, ${\beta }_{\mathrm{vv}-\mathrm{vw}}$, and ${\beta }_{\mathrm{bb}+\mathrm{jb}}$. Using these coefficients, we reconstructed $\overline{\mathbf{B}}$ and compared it with the DNS results. In the kinematic regime, where $\overline{\mathbf{B}}$ remains weak, all models agree well with DNS. In the nonlinear regime, however, the field reconstructed with ${\beta }_{\mathrm{vv}-\mathrm{vw}}$ alone deviates from DNS and grows without bound. Incorporating the turbulent magnetic diffusion term ${\beta }_{\mathrm{bb}+\mathrm{jb}}$ suppresses this unphysical growth and restores consistency. Specifically, ${\overline{B}}_{DNS}$ saturates at approximately 0.23 in the nonlinear regime. The reconstructed $\overline{B}$ using ${\beta }_{EM-HM}$ saturates at $\overline{B}$∼0.3. When ${\beta }_{vv-vw+bb+jb}$$(={\beta }_{vv-vw}+{\beta }_{bb+jb})$ is used, $\overline{B}$ varies from about 0.3 to 0.23. These results indicate that kinetic helicity reduces $\beta$ (or provides a negative contribution), thereby amplifying $\overline{\mathbf{B}}$, whereas turbulent current helicity, together with turbulent magnetic and kinetic energies, enhances $\beta$, thus suppressing $\overline{\mathbf{B}}$ in the nonlinear regime. In this respect, the new form of $\beta$ differs from the conventional one, which acts solely to diffuse the magnetic field. Full article

This article presented a method for grading and visualising corrosion in steel pedestrian bridges using Building Information Modelling (BIM). Traditional inspection methods are often manual and subjective, which reduces their reliability and repeatability. To enhance the recording and reporting of inspection results, a five-level corrosion severity grading system was developed using matched photographic data from two inspection campaigns conducted in February 2024 and April 2025. The grades were assigned based on visual signs, including surface rust, coating damage, and flaking. A Dynamo script was used to link each grade to the corresponding elements in a Revit model using colour overrides. The proposed approach enables corrosion data to be integrated into the BIM environment in a clear, structured manner. This helps engineers assess the structure’s condition, monitor changes over time, and make informed maintenance decisions. The workflow was demonstrated using case studies from a steel pedestrian bridge in Aveiro, Portugal. The method is adaptable for future digital twin applications and supports the development of BIM-based tools for bridge asset management. The workflow was applied to over 2600 elements, with 75 visually degraded cases identified and classified into five grades, demonstrating the method’s feasibility for systematic corrosion tracking. The proposed workflow was tested on a coastal steel bridge and could be generalised to other bridges with similar environmental conditions. Full article

This study investigates the ionospheric responses to two successive geomagnetic storms that occurred on 7–8 and 10–11 October 2024 over the Indian equatorial and low-latitude sector. Using GNSS-derived vertical total electron content (VTEC) measurements and the Global Ionosphere Map (GIM)-derived VTEC variation, supported by O/N₂ ratio variations, equatorial electrojet (EEJ) estimates, and modeled equatorial electric fields from the Prompt Penetration Equatorial Electric Field Model (PPEEFM), the distinct mechanisms driving storm-time ionospheric variability were identified. The 7–8 October storm produced a strong positive phase in the morning sector, with VTEC enhancements exceeding 100 TECU, followed by sharp afternoon depletions. This short-lived response was dominated by prompt penetration electric fields (PPEFs), subsequently suppressed by disturbance dynamo electric fields (DDEFs) and storm-induced compositional changes. In contrast, the 10–11 October storm generated a more complex and prolonged response, including sustained nighttime enhancements, suppression of early morning peaks, and strong afternoon depletions persisting into the recovery phase. This behavior was mainly controlled by DDEFs and significant reductions in O/N₂, consistent with long-lasting negative storm effects. EEJ variability further confirmed the interplay of PPEF and DDEF drivers during both events. The results highlight that even storms of comparable intensity can produce fundamentally different ionospheric outcomes depending on the dominance of electrodynamic versus thermospheric processes. These findings provide new insights into storm-time ionospheric variability over the Indian sector and are crucial for improving space weather prediction and GNSS-based applications in low-latitude regions. Full article

The construction industry is responsible for nearly one-third of global greenhouse gas emissions and consumes over 50% of the planet’s natural resources. As population growth continues, the demand for these resources is expected to rise. Within this context, where business models are still largely based on the Linear Economy (LE), the Circular Economy (CE) emerges as a strategy for promoting economic development while reducing dependence on natural resource consumption. To enable the transition from LE to CE, digital tools such as Material Passports (MP) are essential. An MP compiles data and information describing the characteristics of materials to facilitate their recovery and reuse. This study aims to model the MP of a wood-frame panel commercially produced by Tecverde in Brazil. The panel was designed for a building project using 2024 version of Autodesk Revit software. The proposed MP contains 49 parameters grouped into nine categories, and the data were obtained from open databases provided by the company. The results highlight existing challenges related to sustainability parameters, as well as opportunities to incorporate circular value principles into the construction industry. Full article

The MHD (magnetic hydrodynamics) boundary problem in three-dimensional domains of certain types is considered within the framework of discrete potential theory. The discrete character of the information obtained from remote sensing of the Earth and planets of the Solar System can be taken into account when using the basic principles of this theory. This approach makes it possible to reconstruct the spatial distribution of magnetic fields and the velocity field with relatively high accuracy using the heterogeneous data in some network points. In order to restore the magnetic image of a planet with a so-called dynamo, the subsequent approximations approach is implemented. The unknown physical field is represented as a sum of terms of different magnitudes. Such an approach allows us to simplify the nonlinear partial differential equation system of magnetic hydrodynamics and extend it to discrete magnetic field and velocity vectors. The solution of the simplified MHD equation system is constructed for some classes of bounded domains in Cartesian coordinates in three-dimensional space. Full article

The Lomb–Scargle method (LSM) constitutes a robust method for frequency and amplitude estimation in cases where data exhibit irregular or sparse sampling. Conventional spectral analysis techniques, such as the discrete Fourier transform (FT) and wavelet transform, rely on orthogonal mode decomposition and are inherently constrained when applied to non-equidistant or fragmented datasets, leading to significant estimation biases. The classical LSM, originally formulated for univariate time series, provides a statistical estimator that does not assume a Fourier series representation. In this work, we extend the LSM to multivariate datasets by redefining the shifting parameter $\tau$ to preserve the orthogonality of trigonometric basis functions in ${\mathbb{R}}^n$. This generalization enables simultaneous estimation of the frequency, phase, and amplitude vectors while maintaining the statistical advantages of the LSM, including consistency and noise robustness. We demonstrate its application to solar activity data, where sunspots serve as intrinsic markers of the solar dynamo process. These observations constitute a randomly sampled two-dimensional binary dataset, whose characteristic frequencies are identified and compared with the results of solar research. Additionally, the proposed method is applied to an ultrasound velocity profile measurement setup, yielding a three-dimensional velocity dataset with correlated missing values and significant temporal jitter. We derive confidence intervals for parameter estimation and conduct a comparative analysis with FT-based approaches. Full article

This paper introduces a novel BIM-based computational workflow that embeds spatial analysis directly within the Building Information Modelling (BIM) environment to support the evaluation and design of hospital emergency department (ED) layouts. Conventional analyses often depend on external software and repeated data exchange, which limit efficiency and integration with the design process. The proposed method integrates space syntax principles into Revit through Dynamo and custom Python scripts, enabling automated calculation of spatial measures linked to healthcare-specific performance indicators. The workflow was applied to two UK-based ED floor plans in a comparative case study, assessing patient-oriented aspects such as wayfinding, emergency access, and spatial privacy, alongside staff-oriented factors including workstation accessibility and visibility. Results were validated against DepthmapX to ensure consistency and reproducibility. The findings demonstrate that a BIM-native approach can streamline spatial analysis by eliminating import–export cycles, enhancing design iteration, and supporting post-occupancy evaluation. The significance of the study is in providing a decision-support framework for architects and healthcare planners in both designing new and evaluating existing ED layouts, where spatial configuration directly affects efficiency and user experience. Its main contribution is a reproducible workflow that enables real-time evaluation and strengthens the link between spatial analysis and evidence-based healthcare design. Full article

Improving building energy efficiency has become essential for reducing global greenhouse gas emissions. (1) Background: We aim to strengthen early-stage collaboration among stakeholders based on integrated design principles, rather than relying solely on individual designers’ subjective decisions. The goal is to propose an objective method for optimizing apartment building layouts. (2) Methods: Accordingly, key design elements for energy optimization were identified, and corresponding energy usage prediction data were collected to build a database. Generative Design (GD) techniques were applied to generate and evaluate alternative layout configurations. (3) Results: The conventional apartment block layout process, which heavily depends on the expertise and intuition of experienced designers, was automated using Revit-Dynamo. An energy optimization method from the integrated design perspective was subsequently proposed. (4) Conclusions: GD enabled the identification of comprehensively optimized layout alternatives. We demonstrate the applicability of Revit-Dynamo-GBS in apartment complex design from an integrated design perspective and suggest improvements to existing certification systems and procedures in light of domestic policy considerations. Full article

The rapid growth of the semiconductor industry has created a bottleneck in which traditional manual methods for designing fabrication plants (fabs) cannot keep pace with their high complexity and short technological lifecycles. This problem stems from the critical mismatch between a fab’s multiyear construction timeline and the rapidly shrinking lifecycle of the advanced chips it is built to produce. To address this challenge, the present study proposes a methodological framework that uses dynamic generative design within a Building Information Modelling (BIM) environment. This approach applies algorithms to generalized models to generate and evaluate numerous potential design solutions automatically. For facility layouts, the framework produces plans that balance spatial efficiency, material flow, and stringent cleanroom protocols. For complex utility systems, it moves beyond simple clash detection to proactively generate resource-efficient, clash-free routing paths that consider both constructability and long-term maintainability. The primary contribution of this study is a standardized, data-agnostic design process that enhances design quality without requiring sensitive project data, establishing a robust foundation for future Digital Twin integration. Full article

Steel reinforcement is one of the most important materials used in the construction industry. This research optimizes reinforcement bar fabrication by integrating Building Information Modeling (BIM) with visual programming in Dynamo. On-site rebar cutting and bending generate significant material waste, increasing costs and environmental impact. To address this, an intelligent Dynamo script was developed to extract detailed 3D rebar and 4D scheduling data from BIM models. The script optimizes material usage by specifying cut-off lengths to improve reuse and minimize waste. Validation through two real-world case studies demonstrated the method’s significant potential. Effectiveness was assessed using benchmarks comparing the number of bars saved, waste reduced, and overall cost savings. The study confirms that optimized fabrication significantly cuts waste and cost. Its effectiveness, however, varies with rebar type and structural component, with the most significant gains observed in medium-length bars and pile caps. By offering a novel tool for sustainable construction, this research advances BIM-enabled reinforcement design and material optimization. Full article

This study investigates the origin and amplification of magnetic fields in planets and galaxies, emphasizing the foundational role of a seed magnetic field (SMF) in enabling dynamo processes. We propose a universal mechanism whereby an SMF arises naturally in systems where an orbiting body rotates non-synchronously with respect to its central mass. Based on this premise, we derive a general equation for the SMF applicable to both planetary and galactic scales. Incorporating parameters such as orbital distance, rotational velocity, and core radius, we then introduce a dimensionless factor to characterize the amplification of this seed field via dynamo processes. By comparing model predictions with magnetic field data from the solar system and the Milky Way, we find that the observed magnetic fields can be interpreted as the product of a universal gravitationally induced SMF and a body-specific amplification factor. Our results offer a novel perspective on the generation of magnetic fields in a wide range of astrophysical contexts and suggest new directions for theoretical investigation, including the environments surrounding black holes. Full article

This study investigates the comparative applicability of Somaloy 700HR 5P and Fe-5.0 wt.%Si powders for axial flux permanent magnet (AFPM) motor cores in low-speed electric vehicles. Optimal forming conditions were derived through Taguchi-based simulations, considering corner radius, forming temperature, and forming speed, followed by prototype fabrication and validation. Simulation and SEM-EDS analyses confirmed consistent density distribution trends, and XRD verified phase stability during forming. While Fe-5.0 wt.%Si exhibited ~10% ± 2 superior electromagnetic performance in the powder state, its motor dynamo performance decreased by 19–25% (n = 1) compared to Somaloy 700HR 5P. This discrepancy was attributed to its ~4% lower target density (7.19 ± 0.02 g/cm³ vs. 7.51 ± 0.01 g/cm³, n = 3), assembly-induced mechanical losses, and non-uniform insulation layer caused by residual H₃PO₄ and Mo segregation. Somaloy 700HR 5P, despite a higher relative density variation (0.084 ± 0.002 g/cm³ vs. 0.063 ± 0.003 g/cm³ for Fe-5.0 wt.%Si), achieved an average density close to 7.5 g/cm³ and delivered more stable motor performance. Overall, Somaloy 700HR 5P was identified as a more suitable candidate for AFPM motor cores in low-speed EV applications, balancing formability and electromagnetic performance. Full article

Using the results of numerical simulations and solar observations, this study shows that the transition from deterministic chaos to hard turbulence in the magnetic field generated by the emerging small-scale, near-surface (within the Sun’s outer 5–10% convection zone) solar MHD dynamos occurs through a randomization process. This randomization process has been described using the concept of distributed chaos, and the main parameter of distributed chaos $\beta$ has been employed to quantify the degree of randomization (the wavenumber spectrum characterising distributed chaos has a stretched exponential form $E\left(k\right)\propto exp-{(k/k_{\beta })}^{\beta }$). The dissipative (Loitsianskii and Birkhoff–Saffman integrals) and ideal (magnetic helicity) magnetohydrodynamic invariants govern the randomization process and determine the degree of randomization $0<\beta \le 1$ at various stages of the emerging MHD dynamos, directly or through Kolmogorov–Iroshnikov phenomenology (the magnetoinertial range of scales as a precursor of hard turbulence). Despite the considerable differences in the scales and physical parameters, the results of numerical simulations are in quantitative agreement with solar observations (magnetograms) within this framework. The Hall magnetohydrodynamic dynamo is also briefly discussed in this context. Full article

It has been previously shown that some short peptides are involved in various cellular processes, such as transcription modulation and regulation of differentiation mechanisms. In particular, the effect of peptides on the neuronal differentiation of human periodontal ligament stem cells has been demonstrated. The goal of this study was to assess the effect of KED, EDR, and AEDG short peptides in stimulating the transdifferentiation of fetal MSCs into induced neuronal cells and prevention of their senescence. We applied a novel in vitro technique for neuronal cell generation, which combines the use of microRNAs, transcription factors, and small molecules to transdifferentiate fetal mesenchymal stem cells into induced cortical neurons. It was shown that the application of AEDG and KED short peptides at the end of the transdifferentiation process decreases the expression of the cell cycle marker p21 by 15% and beta-galactosidase activity by 1.51–2.4 times. However, short peptides did not affect the expression levels of TUj-1 and LaminB1, whose expression also changes during neuronal differentiation. The experiments indicate the potential of AEDG and KED short peptides as modulators of neurogenesis and geroprotectors and suggest that they can be used as stimulators of neuronal differentiation. Full article