Search Results (274)

Floating roof seal integrity is critical for safety and emission control in petroleum storage tanks, yet current detection methods suffer from spark risks and operational inefficiencies. This study proposes an intrinsically safe, non-contact leakage detection system utilizing oil-swellable rubber actuators coupled with a linear magnetic transmission mechanism. By integrating quasi-static experiments with finite element simulations, we investigated the impact of permanent magnet geometry on transmission performance. The results establish a “thickness priority principle”, revealing that increasing magnet thickness nonlinearly enhances shear force and transmission efficiency, whereas increasing width yields diminishing returns due to magnetic flux leakage and added mass. Furthermore, comparative analysis demonstrates that optimized monolithic magnets significantly outperform arrayed configurations, achieving a 471% increase in shear force and a 3.7-fold improvement in transmission efficiency. Based on these findings, a practical detection device was designed and verified against API 650 standards. The proposed solution offers a reliable, electricity-free, and real-time monitoring method for early leakage detection in hazardous tank environments. Full article

Background/Objectives: Current evidence regarding the association between the temporal bone and paranasal sinus pneumatization remains limited. This study aims to investigate the potential morphological association between zygomatic process pneumatization and sphenoid sinus pneumatization using three-dimensional cone-beam computed tomography. Methods: Cone-beam computed tomography images from 573 individuals aged 16 to 87 years (170 males, 403 females) were evaluated in this study. Zygomatic process pneumatization was assessed in two forms: pneumatized glenoid fossa (a radiolucent defect on the glenoid fossa roof) and pneumatized articular eminence (a radiolucent defect within the articular eminence). The sphenoid sinus was classified into four major pneumatization types: conchal, presellar, sellar, and postsellar. The postsellar configuration was additionally divided into four subtypes—subdorsal, dorsal, occipital, and combined—according to its posteroanterior orientation. Lateral sphenoid sinus pneumatization was categorized into pterygoid, greater wing, full lateral (combining pterygoid and greater wing), lesser wing, and anterior types. Results: The analysis revealed a significant relationship between zygomatic process pneumatization and sphenoid sinus pneumatization (p < 0.001), where the former was detected in 64.0% of participants. The postsellar type represented the most frequent form of sphenoid sinus pneumatization (55.5%), whereas the conchal type was the rarest (1.2%). Conclusions: A significant correlation was observed between the zygomatic process and sphenoid sinus pneumatization, with individuals exhibiting the former tending to display more extensive sphenoid sinus pneumatization Full article

Collisions between over-height vehicles and low-clearance bridges cause infrastructure damage and pose safety risks. Existing detection systems rely primarily on optical sensors, which suffer from performance degradation in adverse weather conditions. This paper presents an alternative approach based on a 94 GHz millimeter-wave radar that achieves velocity-independent height measurement. The proposed technique exploits the ratio of Doppler shifts from two scattering centers on a vehicle, specifically the roof and the wheel–road interface. This ratio depends only on the measurement geometry, as the unknown vehicle velocity cancels algebraically, enabling direct height computation without speed measurement. The paper provides a closed-form height estimation model, analyzes the trade-off between frequency resolution and geometric constancy during integration, and presents experimental validation using a scaled laboratory testbed. An optical tracking system is used solely for ground-truth validation in the laboratory and is not required for operational deployment. Results across six test cases with heights ranging from 20 cm to 46 cm demonstrate an average absolute error of 0.60 cm and relative errors below 3.3 percent. A scaling analysis for representative full-scale geometries indicates that at highway speeds of 80 km/h, integration times in the millisecond range (approximately 3–18 ms for representative 20–50 m measurement standoff) are feasible; warning distance can be extended independently by upstream radar placement. The expected advantage in fog, rain, and dust is based on established W-band propagation characteristics; dedicated adverse-weather and full field validation (including multipath, clutter, and multi-vehicle scenarios) remain future work. Full article

This study evaluates the feasibility of using two affordable thermal cameras (UNI-T UTi260M and UTi260T), which are not designed as automotive sensors, for observing pedestrians and warm objects during night-time driving under low-illumination conditions. The experimental setup includes mounting the camera on the vehicle body (e.g., side mirror area/roof), recording road scenes in urban and rural environments, and selecting representative frames for qualitative and quantitative analysis. The study assesses: (i) observable pedestrian detectability in unlit road sections and under oncoming headlight glare, where visible cameras often lose contrast; (ii) the influence of low ambient temperature and strong cold wind on image appearance (including “whitening”/contrast shifts); and (iii) workflow differences, where UTi260M relies on a smartphone application for streaming/recording, while UTi260T supports PC-based image analysis and temperature-profile visualization. In addition, a calibration-based geometric method is proposed for approximate pedestrian distance estimation from single frames using silhouette pixel height and a regression model based on 1$/h_{px}$, valid for a specific mounting configuration and a known subject height. Results indicate that both cameras can highlight warm objects relative to the background and support visual pedestrian identification at low illumination, including in the presence of oncoming headlights, with UTi260M showing more stable behavior in parts of the tests. This work is a feasibility study and does not claim Advanced Driver Assist Systems (ADAS) functionality; it outlines limitations, repeatability considerations, and a minimal set of metrics and procedures for future extension. All quantitative indicators derived from exported frames are explicitly treated as image-level proxy metrics, not as physical sensor characteristics. Full article

Historic towns often lack thorough records, complicating the study of long-term material changes in the built environment. This study develops RoofChronoNet, a machine learning workflow that extracts roof covering classes from grayscale imagery and quantifies roofscape change over time. Applied to Tirilye (Bursa, Turkey), historical aerial photographs from 1970 and 1984 are colourised using a pix2pix generative adversarial network trained on 2022 imagery. A YOLOv11m-seg model then detects roof surfaces and classifies them into three roof covering categories: red, white, and dark grey, producing diachronic roofscape maps for 1970–2022. Bounding box detection reached mask mAP@0.50 of 0.81 (2022), ≈0.71 (1984), and 0.76 (1970, single class), while class-averaged mask mAP@0.50 was lower due to pixel-level delineation complexity. Results indicate the persistence of red-tiled roof regimes within the historic core alongside a growing presence of white and dark-grey roof coverings in peripheral areas, consistent with renovation-driven material diffusion after the 1980s. Methodologically, the study contributes a reproducible framework that operationalises chromatic differentiation as a measurable variable for mapping roof covering regimes in planning history research using monochrome historical aerial imagery. RoofChronoNet supports heritage-oriented and planning history interpretations of material regime shifts in data-scarce contexts; however, colourised outputs are synthetic and probabilistic, and spatial inferences should be corroborated with archival or field-based evidence where feasible. Full article

Transitioning toward a circular economy requires not only solutions involving technical component reuse but also mechanisms that reduce risk and increase confidence among market stakeholders. Steel-faced sandwich panels, widely used in façades and roofs, constitute a significant urban material stock, yet their reuse is constrained by information asymmetry, liability concerns, and the absence of verifiable condition data. In this study, we develop an integrated end-to-end workflow—combining controlled panel recovery, Unmanned Aerial Vehicle (UAV) inspection, deep learning-driven damage detection, and Building Information Modeling (BIM)-linked material passports—to enable traceable, evidence-based reuse decisions. Validated through a pilot façade assembly and disassembly process, the methodology successfully quantified 4845.90 cm² of mechanical damage across 10 panels, with all orthomosaic and detection outputs fully integrated into the digital passport environment. By standardizing component-level condition records, this approach reduces perceived risk and provides the technical assurance necessary to unlock a trusted second-hand marketplace for sandwich panels. Framed within an urban metabolism perspective, the findings demonstrate how digital transparency can bridge the gap between material recovery and market valuation. Full article

Benzisothiazolinone (BIT) is a commonly used biocide in water-based products, which can enter the environment from household and personal care products, as well as from leaching off building facades and roofs due to rainfall, eventually reaching rivers through stormwater runoff and raising ecological concerns due to its high aquatic toxicity. Detecting benzisothiazolinone, particularly in the environment is crucial due to health and regulatory requirements. This study explores electrochemical techniques and conductive nanomaterials for detecting BIT in environmental samples. Carbon- and gold-based screen-printed electrodes (SPEs) with distinct morphologies were investigated: carbon electrodes as nanoparticles (SPE-C) and single-wall carbon nanotubes (SPE-SWCNTs), and gold electrodes as nanoparticles (SPE-Au-BT) and thin films (SPE-Au-AT). Cyclic voltammetry and square-wave voltammetry (SWV) were optimized, with SWV demonstrating superior sensitivity—showing a two-order improvement with carbon-based electrodes and a 30-fold enhancement with gold-based electrodes. The lowest detection limits were 40 nM for carbon and 80 nM for gold nanoparticle-based electrodes. SPE-C achieved good recovery in river water, confirming its effectiveness for BIT monitoring with minimal interference from common ions or saccharin. These sensors can be easily used for everyday detection and monitoring of BIT in river water, ensuring a screening programme that supports the development of adequate regulatory guidelines. Full article

This paper proposes a building reconstruction framework for airborne LiDAR data to address the challenge of automated modeling under conditions of uneven point cloud density and missing vertical walls, generating high-precision and structurally compact 3D building models. The method first combines adaptive resolution hypervoxels with a global graph cut optimization strategy to extract precise roof plane primitives from sparse point clouds of buildings. Subsequently, it infers building facades and internal vertical walls based on point cloud projection contours and height change detection, thereby completing the wall structures commonly missing in airborne LiDAR data. Finally, a feature line constraint term is introduced into the hypothesis-and-selection-based reconstruction framework to guide the structural optimization of candidate planes, ensuring the reconstructed model closely matches the actual building geometry. The proposed method was evaluated on multiple public airborne LiDAR datasets, demonstrating its effectiveness through qualitative and quantitative comparisons with various state-of-the-art approaches. Full article

Accurate identification of concealed coal seam structures, such as folds or faults, is crucial for safe and effective production in the coal mining industry. In-seam seismic exploration serves as a promising technique for advanced detection of coal seam structures, but traditional numerical simulation methods easily produce errors when coping with irregular interfaces. This study uses the curvilinear grid finite-difference method (FDM) for modeling the 3D channel wave propagation. The body-fitted grids are utilized to conform to undulating interfaces, while the DRP/opt MacCormack difference scheme and the fourth-order Runge–Kutta algorithm are applied for the spatial and temporal derivative approximation, in that order. The forward and backward extrapolation for in-seam waves are implemented in the curvilinear coordinates. The roofs and floors of coal seams and special structures are imaged by reverse-time migration (RTM) using an excitation amplitude imaging condition. Numerical results show that compared with conventional methods, the curvilinear grid method effectively reduces spurious scattering caused by the staircase approximation, improves the modeling accuracy of channel waves, and enhances the continuity and interpretability of imaged coal-seam interfaces and structural boundaries. The proposed method has the potential to enhance the accuracy of channel wave exploration under complex geological conditions, supporting advanced hazard detection in coal mines. Full article

The monitoring and conservation of built heritage is a major challenge for the scientific community, given the continuous degradation caused by natural, anthropogenic and climatic factors. The generation of high-resolution 3D documentation is important in the diagnosis of deterioration in historic buildings and the planning of conservation and restoration efforts. The present study proposes an integrated, multi-source workflow combining terrestrial laser scanning (TLS), unmanned aerial vehicle (UAV) photogrammetry, and 3D camera interior scanning. This workflow was employed to document and evaluate the Casa Rusănescu monument in Craiova, Romania. The following processes were incorporated: coordinated acquisition, processing, alignment, evaluation of geometric consistency and deviation-based diagnosis. The diagnosis process include measuring the distance between data clouds and analyzing surface roughness, curvature, planarity and linearity. The workflow was designed to be applicable in real urban conditions, ensuring the coverage of façades, interiors and roof structures. The final, combined dataset contained over 235 million points and includes both interior and exterior geometries. This process helped identify various types of damage, such as cracks, exfoliation, plaster detachment, moisture-related changes, and geometric deformations. An additional AI-assisted validation step (Twinspect) was used to cross-check the degradation indicators derived from point-cloud analyses. The findings suggest that using multiple sensors improves spatial completeness, enhances anomaly detection, and establishes a reliable baseline prior to restoration interventions and long-term monitoring. This methodology facilitates the development of digital twins and GIS-based risk assessments, thereby providing a scalable solution for heritage preservation. Full article

Ancient Chinese architecture, with its typical symmetrical structures, curved roofs, and upturned eaves presenting a unique architectural aesthetic, is a treasure of Chinese culture. Recently, unmanned aerial vehicle oblique photogrammetry and laser scanning technology have greatly facilitated the realistic replication of ancient buildings and have become crucial data sources for the HBIM of ancient buildings. However, parameter extraction and geometric model representation are more difficult because of the curved surfaces and upturned eaves of traditional Chinese roofs. As symmetrical features are typical of ancient Chinese architecture, the parameter quantity and modelling difficulty of the model representation can be effectively reduced by recognizing the symmetrical structure of traditional Chinese roofs and using “mirror replication” to quickly generate the other half of the model. Accurate symmetry detection and highly efficient parameter extraction are crucial for the HBIM of traditional Chinese roofs. Therefore, in this study, a deep learning network, namely, TCRSym-Net, is proposed to identify the symmetry from point clouds of traditional Chinese roofs. Each roof point cloud is then relocated and reoriented to obtain longitudinal and cross sections, and parametric modelling scripts are coded in Dynamo to model traditional Chinese roofs via curve lofting and solid Boolean operations. The experimental results reveal that the symmetry detection network is effective for symmetry detection, and five different types of traditional Chinese roofs are successfully recreated, which confirms the dependability of the method. Full article

Controllable shock wave (CSW) technology offers a promising approach for improving roof cavability and safety in underground mining, yet its field-scale mechanisms remain insufficiently clarified. This study develops and validates an optimized CSW pre-cracking procedure for hard top coal at the Liuxiang Coal Mine. A series of CSW-induced fracturing experiments were conducted across multiple boreholes under real operating conditions, and the causal relationships between loading parameters, induced fracture propagation, and mining performance were systematically evaluated. Segmented water injection leak detection was used to quantify fracture development in the No. 3 coal seam. The results demonstrate that CSW significantly enhances top-coal cavability: the proportion of large coal blocks was reduced by approximately 25%, and the average roof pressure step distance decreased from the baseline of 16.12–20.03 m to 13.12–13.82 m. These improvements indicate more efficient energy release, a more stable roof structure, and safer working conditions. Overall, this study provides a technically verified and operationally optimized CSW procedure, highlighting its strong potential to support safer and more sustainable hard top-coal mining. Full article

Urban building energy modeling (UBEM) is crucial for assessing energy consumption patterns at the city-scale and for supporting data driven planning and decarbonization strategies. However, its practical deployment is often hindered by the need to balance detailed physics-based simulations with acceptable computation times when thousands of buildings are involved. This work presents a large-scale real world UBEM case study and proposes a workflow that combines EnergyPlus simulations, high-performance computing (HPC), and open urban datasets to model the energy consumption of the building stock in the Municipality of Bologna, Italy. Geometric data such as building footprints and heights were acquired from the Bologna Open Data portal and complemented by aerial light detection and ranging (LiDAR) measurements to refine elevations and roof geometries. Non-geometrical building characteristics, including wall materials, insulation levels, and window properties, were derived from local building regulations and the European TABULA project, enabling the assignment of archetypes in contexts where granular information about building materials is not available. The pipeline’s modular design allows us to analyze different combinations of retrofitting scenarios, making it possible to identify the groups of buildings that would benefit the most. A key feature of the workflow is the use of Leonardo, the supercomputer hosted and managed by Cineca, which made it possible to simulate the energy consumption of approximately 25,000 buildings in less than 30 min. In contrast to approaches that mainly reduce computation time by simplifying the physical model or aggregating representative buildings, the HPC-based workflow allows the entire building stock to be individually simulated (within the intrinsic simplifications of UBEM) without introducing further compromises in model detail. Overall, this case study demonstrates that the combination of open data and HPC-accelerated UBEM can deliver city-scale energy simulations that are both computationally tractable and sufficiently detailed to inform municipal decision-making and future digital twin applications. Full article

Background/Objectives: Pulsed field ablation (PFA) is increasingly used for pulmonary vein isolation (PVI). One of the emerging single-shot PFA catheters is the variable-loop circular catheter (VARIPULSE™, Biosense Webster, Inc.) which is fully integrated into a three-dimensional mapping system. However, the evidence for the feasibility of ablation of non-pulmonary vein targets is still limited using the VARIPULSE catheter. In this study, we summarize our experience in PVI and mapping/ablation of non-pulmonary vein sites in patients with atrial fibrillation (AF) and complex atrial substrate and arrhythmias using the VARIPULSE catheter. Methods: All patients with paroxysmal or persistent AF who underwent catheter ablation using the VARIPULSE catheter were retrospectively included. PVI was performed in all patients. Spontaneous or inducible atrial flutters were mapped and ablated. Empiric lines were performed at the operator’s discretion. Acute outcomes and complications were analyzed. Results: the study included 60 patients; 25 (41.6%) were females and mean age was 67.15 ± 9.01 years. Thirty four (60%) had persistent AF and six (10%) patients had atrial flutter as the initial rhythm during the index procedure. All patients had PVI using the PFA as per protocol. Most of the patients (76.7%) had non-pulmonary vein ablation sites; posterior wall isolation was performed in 25 (41.7%) patients, roof line in 9 (15%) patients, anterior line in 16 (26.7%) patients, cavotricupsid isthmus in 11 (18.3%) patients and superior vena cava isolation in two (3.3%) patients. Overall, 27 patients had atrial flutters during the index procedure that were mapped and ablated using the VARIPULSE catheter. All had termination of atrial flutter except for one patient. Major complications were not detected. Conclusions: Mapping and ablation of atypical atrial flutter and non-pulmonary vein targets are feasible and safe using the VARIPULSE platform. Full article

This study investigates the seismic retrofit of historic single-nave churches through the optimization of roof diaphragms designed to enhance energy dissipation. The proposed strategy introduces a deformable box-type diaphragm above the existing roof, composed of timber panels and steel connectors with a cover of steel stripes, where energy dissipation is concentrated in the connections. The retrofit design is guided by the estimation of Equivalent Damping Ratio (EDR) instead of the usually adopted resistance criterion, considering an energy-based approach to improve global seismic performance while preserving architectural integrity. In this way, the retrofitted configuration of the roof can be considered a damper. Three numerical phases are presented to assess the effectiveness of the equivalent damping-based intervention. In the first one, the seismic response of the initial non-retrofitted configuration is implemented using a 3D linear finite element model subjected to a response spectrum. Subsequently, nonlinear equivalent models subjected to spectrum-compatible accelerograms are implemented, simulating the possible retrofitted configurations of the roofs to detect the optimum damping and finding the corresponding roof diaphragm configuration. In the third one, the response of the detected retrofitted configuration is also evaluated by nonlinear 3D model subjected to accelerograms. The three phases with the relative numerical approaches are here applied to a case study, located in a high seismic hazard area. The results demonstrate that the EDR-based methodology can optimize the retrofitted roof diaphragm configuration; the nave transverse response is improved in comparison with that designed with the traditional approach, considering only the over-strength of the interventions. Comparisons about the approaches based on the EDR and the strength criteria are presented in terms of lateral displacements, in-plane shear acting on the roof diaphragm, and in-plane stresses on the façade. Full article