Search Results (51)

This article presents a diagnostic study on the characterization of community and walkable rooftops in Barcelona’s historic district. The study aims to evaluate the potential for efficient improvement solutions that align with contemporary regulations for safety, accessibility, and energy efficiency. It is part of the REVTER project, which seeks to recover flat roofs as non-public collective areas in densely populated environments. The research emphasizes the importance of understanding the technical aspects of these rooftops before interventions, focusing on construction and performance to establish guidelines for future improvements. The methodology includes cartographies, on-site inspections, and performance evaluations, aiming to create a district-level overview, characterize roofing solutions chronologically, assess current technical performance, and identify deficiencies to develop intervention guidelines. Key findings highlight the evolution of construction practices across three distinct periods, revealing significant shifts in materials and techniques. The research underscores the necessity of data-driven technical characterization and proposes a systematic approach for evaluating historic architectural spaces. By selecting a broad study sample and using a GIS approach, the study sets a precedent for understanding and improving the technical characteristics of urban rooftops, contributing significantly to sustainable urban development and heritage conservation within Ciutat Vella. Full article

This study presents the development of a Korean-specific safety checklist for fishing vessels under 10 tons, aiming to strengthen self-safety management in small-scale fisheries. The research first reviewed representative European self-inspection systems and checklists from Norway, Denmark, the United Kingdom, and Ireland, which have established integrated safety management schemes combining self-managed risk assessment with periodic inspection. Following on these systems, three human and system analysis methods were employed: SRK/SLMV for identifying human error types and operational error mechanisms, CREAM for evaluating cognitive performance conditions and failure probabilities, and STPA for analyzing control-loop deficiencies and unsafe interactions within the system. Based on these analyses, a Korean-specific safety checklist was developed and structured into three components: Pre-operation, Post-operation, and Periodic Inspection. Each part was designed to reflect the actual operational characteristics of coastal fishing vessels while maintaining consistency with domestic regulatory requirements. The resulting checklist integrates human, technical, and organizational dimensions, providing a structured tool for evaluating risks and supporting self-assessment-based safety management in daily fishing operations. Full article

Accurate and timely identification of cutter anomalies is crucial for ensuring the safety and efficiency of shield tunneling. To address the issues of poor timeliness and high costs associated with traditional periodic manual inspection methods, this study establishes a cutter anomaly identification model based on the BO-Light GBM algorithm, focusing on slightly weathered metamorphic rock formations. Six parameters closely related to the tunneling state were selected to construct the feature set, and one-class support vector machines (SVMs) were employed to remove anomalous samples. On this basis, a baseline Light GBM model with preset hyperparameters was developed, achieving a preliminary accuracy of 96.04%. Further hyperparameter tuning using Bayesian optimization boosted the overall accuracy of the final BO-Light GBM model to 99.40% while improving training efficiency by approximately 50% compared to exhaustive grid search. Interpretability analysis conducted via SHAP values revealed that chamber pressure, cutterhead rotation speed, total thrust, and cutterhead torque were the primary contributing features, with patterns consistent with actual tunneling conditions, confirming the accuracy of the model’s predictions. The research outcomes provide valuable theoretical guidance and technical support for similar engineering applications. Full article

Fotis Kontoglou (1895–1965) was a prominent Greek painter and writer, known primarily for revitalizing byzantine painting in the 20th century and being one of the first artist-conservators in Greece active at this period. The current study represents the first systematic attempt to examine seven (7) icons (i.e., ecclesiastical panel paintings) attributed to Kontoglou, currently located in two famous monasteries in Laconia, Greece. The research utilized exclusively non-destructive analytical techniques, namely digital optical microscopy, UV-induced visible fluorescence photography (UVIVF), and portable X-ray fluorescence (p-XRF) spectroscopy, to identify the materials—particularly pigments—employed in the corresponding paintings. The results are interpreted under the light of Kontoglou’s own writings on painting, in particular his “Ekphrasis” painting manual. Preliminary assessments of surface morphology and state of preservation were achieved through macroscopic and microscopic probing, as well as through inspection under ultraviolet light, while further analysis was performed using portable X-ray fluorescence spectroscopy. The results confirm the employment of both traditional and modern synthetic inorganic components, while comparisons with the pigments listed in Kontoglou’s “Ekphrasis” painting manual suggest his persistent use of a rather limited palette of pigments. Nevertheless, despite the fact that the paintings were executed in a small period of time (1954–1956), data revealed notable differentiation between the studied icons, which probably indicates procurement of materials from various sources. Given the scarcity of technical investigations of modern (20th century) paintings, this study is relevant and reveals some interesting hints, which may pertain to the trends of the mid-20th century Greek paint market, like, e.g., the rather limited distribution of Ti-white. Additionally, the current findings contribute considerably towards understanding Kontoglou’s artistic methods during a highly creative period and can be utilized to support future conservation efforts. Ultimately, the current preliminary study sheds light on some methodological aspects of the pertinent research and assists towards establishing a detailed protocol for future studies. Full article

This paper proposes a hybrid machine learning framework for detecting electricity fraud within the broader context of Non-Technical Losses (NTLs) in power-distribution systems. The framework combines unsupervised anomaly detection using Isolation Forest with supervised classification through XGBoost, exploiting the complementary strengths of both algorithms. Using real consumption data from a Peruvian utility, the approach integrates domain-informed feature engineering to capture behavioral, temporal, and contextual indicators of irregular usage. To address the extreme class imbalance inherent to fraud datasets, the SMOTETomek hybrid resampling technique was applied, enhancing minority-class representation and decision boundary clarity. Experimental results achieved high predictive performance on the test set (AUC-ROC = 0.999, F1-score = 0.77) using an optimized decision threshold of 0.6. Moreover, SHAP-based interpretability analysis identified extreme monthly variations, prolonged low-consumption periods, and tariff category as key behavioral predictors of fraudulent activity. The robustness of the proposed framework was further validated through a 5-fold cross-validation procedure during the training phase, ensuring consistent performance across different data partitions. Overall, the proposed framework demonstrates not only robust and explainable performance but also practical operational value, providing utilities with a scalable data-driven tool to optimize inspection strategies and maximize recovery of non-technical losses. Full article

The vehicle braking system is the system that provides the greatest safety when driving on public roads. That is why European legislation places great emphasis on carrying out periodic technical inspections (PTIs) (annually or whenever necessary) to protect both the driver and especially other traffic participants. Our paper analyzes a group of 54 Dacia-Logan cars, participating in traffic both in Romania and in Europe, especially in terms of braking systems, upon arrival at PTI stations, presenting the efficiency of these systems and the variation pattern depending on the frequency of the cars. It is thus found that the efficiency of the service brake has values between 53 and 87%, with an average of about 69%, and the efficiency of the safety brake has values between 23 and 67%, with a much lower average of only 34% (there are, obviously, few extreme positive values, but also negative ones). There are also imbalances both in terms of the necessary braking force, which is up to 24% for the front axle (between the left–right wheels) and up to 30% between the wheels for the rear axle. The braking force values on the two wheels were in the ranges of 2000–2200 N for the front axle, between 1715–1850 N for the rear axle and for the service brake, and between 1360 and 1435 N for the safety brake. Full article

As the world increasingly gravitates towards green, environmentally friendly and low-carbon lifestyles, wind power has become one of the most technologically established renewable energy sources. However, with the continuous increase in their output power and height, wind turbine towers are subjected to higher-intensity alternating wind loads. This makes critical components more prone to fatigue failure, potentially leading to major accidents such as tower buckling or turbine collapse. High-strength bolts play a vital role in supporting towers but are susceptible to fatigue crack initiation under long-term cyclic loading, necessitating regular inspection. Types of wind turbine bolts mainly include high-strength bolts, stainless steel bolts, anchor bolts, titanium alloy bolts, and adjustable bolts. These bolts are distributed across different parts of the turbine and perform distinct functions. Among them, high-strength bolts in the tower are particularly critical for structural support, demanding prioritized periodic inspection. Compared to destructive offline inspection methods requiring bolt disassembly, non-destructive testing (NDT) has emerged as a trend in defect detection technologies. Therefore, this review comprehensively examines various types of NDT techniques for wind turbine towers’ high-strength bolts, including disassembly inspection techniques (magnetic particle inspection, penetration inspection, intelligent torque inspection, etc.) and non-disassembly inspection techniques (ultrasonic inspection, radiographic inspection, infrared thermographic inspection, etc.). For each technique, we analyze the fundamental principles, technical characteristics, and limitations, while emphasizing the interconnections between the methodologies. Finally, we discuss potential future research directions for bolt defect NDT technologies. Full article

Background: In advanced heart failure patients implanted with a fully magnetically levitated HeartMate 3 (HM3) Abbott left ventricular assist device (LVAD), it is unknown how the role of the LVAD outpatient clinic may affect the long-term survival after hospital discharge. Our objective is to share our standardized protocol for outpatient care, to describe the role of the LVAD outpatient clinic in postoperative long-term care after LVAD implantation, and to report survival. Methods: We retrospectively reviewed all patients implanted with HM3 LVAD in our institute between September 2015 and January 2025. Patients who received HeartWare Ventricular Assist Device (HVAD) and HeartMate 2 LVAD devices were excluded from our study, to ensure a homogenous cohort focusing on the latest and the only currently used LVAD device generation. We included a total of 48 patients. After LVAD patients are discharged from our center, they are followed in our outpatient clinic in 3-month intervals. During visits, bloodwork, EKG, wound inspection, and echocardiography are performed in addition to LVAD analysis. The role of the outpatient clinic is to detect early signs of deterioration or problems and act accordingly to prevent serious complications. Results: Thirty-three patients (68.7%) are still alive in 2025; two patients (4.2%) had a successful heart transplantation; and thirty-one patients (64.5%) are still on LVAD support. There were 210 total patient years of support. The mean time on device is 4.4 years. During the follow-up period we noticed 15 deaths (31.3%). Notably, there was no technical device-related death. Kaplan–Meier analysis estimated an overall survival rate of 97.9%, 92.8%, 83.7%, and 51.1% at 1, 2, 4, and 8 years, respectively. Conclusion: Strict control of patients after discharge in an outpatient clinic is essential for the long-term survival of these patients. A well-structured outpatient program is of utter importance to avoid LVAD-related complications and should be a cornerstone for the treatment, especially in non-transplant centers. Full article

In periodic technical inspections (PTIs), evaluating the braking efficiency of light passenger vehicles at their Maximum Authorized Mass (MAM) presents a practical challenge, as bringing laden vehicles to inspection is often unfeasible due to logistical and infrastructure limitations. The fBrake method is proposed to overcome this issue by estimating braking efficiency at MAM based on measurements taken from vehicles in more accessible loading conditions. In this study, the fBrake method is validated by demonstrating the equivalence of its efficiency estimates extrapolated from two distinct configurations: an unladen state near the curb weight and a partially laden condition closer to MAM. Following the UNE 26110 standard (Road vehicles. Criteria for the assessment of the equivalence of braking efficiency test methods in relation to the methods defined in ISO 21069), roller brake tester measurements were used to obtain force data under both conditions. The analysis showed that the extrapolated efficiencies agree within combined uncertainty limits, with normalized errors below 1 in all segments tested. Confidence intervals were reduced by up to 74% after electronics update. These results confirm the reliability of the fBrake method for M1 and N1 vehicles and support its adoption as an equivalent procedure in compliance with UNE 26110, particularly when fully laden testing is impractical. Full article

Lyophyllum decastes, commonly known as Luronggu, is extensively cultivated across China. It exhibits rich germplasm in China. However, the number of cultivars available for commercial production is limited, highlighting the importance of targeted breeding programs. In this study, we utilized selected breeding and SSR molecular markers to develop improved strains of L. decastes for the first time. The breeding process strictly adhered to China’s national standard for ‘Technical inspection for mushroom selecting and breeding’. It encompassed pure strain isolation, biological classification, primary screening, secondary screening, physiological performance determination, molecular characterization, intermediate test, and demonstration cultivation. As a result, strain ZJLZS002, known for its high yield (380 ± 3.6 g·bag⁻¹), shortened growth period (75.6 ± 1.3 d), and stable traits, is well suited for industrial cultivation. This new cultivar has achieved a significant milestone as the first variety in China to be officially recognized at the provincial level, under the name ‘Zhongjunluronggu No. 1’. Its development signifies a crucial advancement in achieving seed source independence and promotes the replacement of imported varieties with domestic ones, contributing to the sustainable development of China’s edible fungi industry. Full article

Introduction: Hemangioblastomas (HBs) are benign, highly vascular tumors that can be found intracranially or in the spinal region, representing around 2–15% of primary intramedullary tumors. They can occur sporadically or in association with Von Hipple–Lindau (VHL) disease. Despite recent of advancement of nonsurgical treatments, complete surgical resection remains the gold standard of care for the spinal HBs. Materials and Methods: We conducted an international multicenter retrospective analysis of adult patients surgically treated for spinal HBs in four European referral centers between January 2000 and September 2024, with a minimum post-operative follow-up duration of 6 months. Patients’ sex and age at surgical intervention, clinical presentation, and duration symptoms prior to clinical diagnosis were identified. The pre- and post-operative neurological status at 1 and 6 months and at the last visit was assessed using the modified McCormick score (MCS). The extent of surgical resection was divided into gross total resection (GTR) and subtotal resection (STR). Finally, post-operative complications were inspected as well, namely cerebrospinal fluid leaks, infections, hemorrhages and post-operative spinal stability. Results: A total of 35 patients were included in the cohort, with an age median of 52 years (34.5–60) and a slight male predominance (21/35, i.e., 60%). The median follow-up period was 37.5 months (12–75). More than half were located in the cervical region, making it the most common (54.3%). Syrinxes were observed in 23 cases (72%), and HBs were more commonly intramedullary (80%). GTR was achievable in around 88% of cases. Post-operative complications were observed in nine patients (25.7%). Nearly half of patients were discharged into rehabilitations centers (48.5%). Tumor recurrence was seen in 10.3% only. At the last follow-up, an excellent overall post-operative neurological status (positive ∆ McCormick) was observed in most of patients (88%) and was found to be associated with a relatively younger age group. Tumor location and presence of syrinxes did not show any statistical significance regarding clinical outcome. In patients having benefited from intra-operative monitoring, only D-wave changes showed statistical significance regarding post-operative outcome (p < 0.05). Conclusions: A large majority of patients operated for a spinal HB demonstrated favorable outcome after surgery, with unchanged or improved neurological status. Advanced age could have an impact on the post-operative neurological outcome. Other factors such as tumor size, location, and the presence of syrinx did not seem to significantly impact the neurological outcome. Finally, the surgery of these vascular lesions with no possibility of debulking or piece-meal removal and requiring “en bloc” resection is technically demanding and should be performed by experienced teams in spine and spinal cord surgery only. Full article

Over the past few decades, a significant number of large concrete structures with deterioration problems related to the alkali–silica reaction (ASR) have been identified in Portugal and worldwide. Assessing the condition of ASR-affected concrete dams involves both diagnosis and prognosis. Diagnosis evaluates the structure’s current state, while prognosis predicts deterioration and safety implications. This is key to estimate the period during which the structure will effectively perform its function, and essential for the timely and cost-effective planning of the necessary mitigation, rehabilitation, and/or reconstruction works. This article aims to contribute to the ongoing discussion of this topic by the scientific and technical community and, therefore, presents the methodology adopted to assess the condition of a severely ASR-affected concrete dam in Portugal, the Alto Ceira dam, in which the concrete was produced with susceptible to ASR quartzitic aggregates and that was decommissioned and replaced by a new one in 2014. The article provides a brief review of the diagnosis and prognosis of the ASR in concrete dams, presents and analyses the results from laboratory testing (including chemical, microstructural, physical, mechanical, and expansion tests), in-situ testing, structural monitoring systems, visual inspections, and numerical modelling, aiming at assessing ASR impacts and evidencing the utility of the reported methodology on the appraisal of ASR-affected structures. Full article

The perception of the vehicle’s environment is crucial for automated vehicles. Therefore, environmental sensors’ reliability and correct functioning are becoming increasingly important. Current vehicle inspections and self-diagnostics must be adapted to ensure the correct functioning of environmental sensors throughout the vehicle’s lifetime. There are several promising approaches for developing new test methods for vehicle environmental sensors, one of which has already been developed in our previous work. A method for testing vehicle front cameras was developed. In this work, the method is improved and applied again. Various test vehicles, including the Tesla Model 3, Volkswagen ID.3, and Volkswagen T-Cross, are stimulated by simulating driving scenarios. The stimulation is carried out via a tablet positioned before the camera. The high beam assist is used to evaluate the vehicle’s reaction. It was observed whether the vehicle switched from high to low beam as expected in response to the stimulation. Although no general statement can be made, the principle of stimulation works. A vehicle reaction can be successfully induced using this method. In further test series, the influence of display brightness is examined for the first time in this work. The results show that the display brightness significantly influences the test procedure. In addition, the method is validated by stimulation with colored images. It is shown that no complex traffic simulation is necessary to trigger a vehicle reaction. In the following validation approach, the CAN data of the Tesla Model 3 is analyzed during the tests. Here, too, the assumption that the vehicle reaction is based solely on the detected brightness instead of identifying road users is confirmed. The final validation approach examines the method’s applicability to other vehicles and high beam assist technologies. Although the method could not be used on the Volkswagen T-Cross due to a fault detected by the vehicle’s self-diagnosis, it worked well on the Volkswagen ID.3. This vehicle has a dynamic light assist in which individual segments of the high beam are dimmed during stimulation. Although the method developed to stimulate vehicle front cameras is promising, the specific factors that trigger the vehicle responses remain to be seen. This uncertainty suggests that further research is needed better to understand the interaction of stimulation and sensor detection. Full article

This study introduces fBrake, a novel simulation method now designed for use in periodic technical inspections of M₁ and N₁ vehicle categories, addressing challenges posed by Directive 2014/45/EU. The directive mandates that braking efficiency must be measured relative to the vehicle’s maximum mass, which often results in underperformance during inspections due to vehicles typically being unladen. This discrepancy arises because the maximum braking forces are proportional to the vertical load on the wheels, causing empty vehicles to lock their wheels prematurely compared to laden ones. fBrake simulates the braking forces of unladen vehicles to reflect a laden state by employing an optimal brake-force distribution curve that aligns with the vehicle’s inherent braking behavior, whether through proportioning valves or through electronic brake distribution systems in anti-lock-braking-system-equipped vehicles. Our methodology, previously applied to heavy vehicles, involved extensive experimentation with a roller brake tester, comparing the actual braking performances of dozens of vehicles to those of their simulated counterparts using fBrake. The results demonstrate that fBrake reliably replicates the braking efficiency of laden vehicles, validating its use as an accurate and effective tool for braking system assessments in periodic inspections, irrespective of the vehicle’s load condition during the test. This approach ensures compliance with regulatory requirements while enhancing the reliability and safety of vehicle inspections. Full article

Thousands of particle number (PN) counters have been introduced to the European market, following the implementation of PN tests during the periodic technical inspection (PTI) of diesel vehicles equipped with particulate filters. Expanding the PN-PTI test to gasoline vehicles may face several challenges due to the different exhaust aerosol characteristics. In this study, two PN-PTI instruments, type-examined for diesel vehicles, measured fifteen petrol passenger cars with different test protocols: low and high idling, with or without additional load, and sharp accelerations. The instruments, one based on diffusion charging and the other on condensation particle counting, demonstrated good linearity compared to the reference instrumentation with R-squared values of 0.93 and 0.92, respectively. However, in a considerable number of tests, they registered higher particle concentrations due to the presence of high concentrations below their theoretical 23 nm cut-off size. The evaluation of the different test protocols showed that gasoline direct injection engine vehicles without particulate filters (GPFs) generally emitted an order of magnitude or higher PN compared to those with GPFs. However, high variations in concentration levels were observed for each vehicle. Port-fuel injection vehicles without GPFs mostly emitted PN concentrations near the lower detection limit of the PN-PTI instruments. Full article