Search Results (258)

Work-related musculoskeletal disorders (WMSDs) are among the most prevalent occupational health issues, particularly affecting public transport drivers due to prolonged sitting, constrained postures, and poorly adaptable cabins. This study addresses the ergonomic risks associated with tram driving, aiming to evaluate biomechanical load and postural stress in relation to drivers’ anthropometric characteristics. A combined methodological approach was applied, integrating two standardized observational tools—RULA and REBA—with anthropometric modeling based on three representatives European morphotypes (SmallW, MidM, and TallM). ErgoFellow 3.0 software was used for digital posture evaluation, and lumbar moments at the L4/L5 vertebral level were calculated to estimate lumbar loading. The analysis was simulation-based, using digital human models, and no real subjects were involved. The results revealed uniform REBA (Rapid Entire Body Assessment) and RULA (Rapid Upper Limb Assessment) scores of 6 across all morphotypes, indicating moderate to high risk and a need for ergonomic intervention. Lumbar moments ranged from 51.35 Nm (SmallW) to 101.67 Nm (TallM), with the tallest model slightly exceeding the recommended ergonomic thresholds. These findings highlight a systemic mismatch between cabin design and user variability. In conclusion, ergonomic improvements such as adjustable seating, better control layout, and driver education are essential to reduce the risk of WMSDs. The study proposes a replicable methodology combining anthropometric, observational, and biomechanical tools for evaluating and improving transport workstation design. Full article

Unbalanced accelerations occurring during tram travel have a significant impact on passenger comfort and safety, as well as on the rate of wear and tear on infrastructure and rolling stock. Ideally, these dynamic forces should be monitored continuously in real-time; however, traditional systems require high-precision accelerometers and proprietary software—investments often beyond the reach of municipally funded tram operators. To this end, as part of the research project “Accelerometer Measurements in Rail Passenger Transport Vehicles”, pilot measurement campaigns were conducted in Poland on tram lines in Gdańsk, Toruń, Bydgoszcz, and Olsztyn. Off-the-shelf smartphones equipped with MEMS accelerometers and GPS modules, running the Physics Toolbox Sensor Suite Pro app, were used. Although the research employs widely known methods, this paper addresses part of the gap in affordable real-time monitoring by demonstrating that, in the future, equipment equipped solely with consumer-grade MEMS accelerometers can deliver sufficiently accurate data in applications where high precision is not critical. This paper presents an analysis of a subset of results from the Gdańsk tram network. Lateral (x) and vertical (z) accelerations were recorded at three fixed points inside two tram models (Pesa 128NG Jazz Duo and Düwag N8C), while longitudinal accelerations were deliberately omitted at this stage due to their strong dependence on driver behavior. Raw data were exported as CSV files, processed and analyzed in R version 4.2.2, and then mapped spatially using ArcGIS cartograms. Vehicle speed was calculated both via the haversine formula—accounting for Earth’s curvature—and via a Cartesian approximation. Over the ~7 km route, both methods yielded virtually identical results, validating the simpler approach for short distances. Acceleration histograms approximated Gaussian distributions, with most values between 0.05 and 0.15 m/s², and extreme values approaching 1 m/s². The results demonstrate that low-cost mobile devices, after future calibration against certified accelerometers, can provide sufficiently rich data for ride-comfort assessment and show promise for cost-effective condition monitoring of both track and rolling stock. Future work will focus on optimizing the app’s data collection pipeline, refining standard-based analysis algorithms, and validating smartphone measurements against benchmark sensors. Full article

Background/Objectives: Public transportation drivers are exposed to a variety of occupational hazards. The scope of this study is to describe the most significant changes in symptoms and work-related disorders in the last decade in a sample of professional drivers from a large Romanian city, and, in particular, the cardio-metabolic and musculoskeletal impact. Methods: A retrospective study on 186 professional tram, trolley, and bus drivers from a total number of 344 employed by the company was conducted. The initial values (pre-employment) of the BMI, blood pressure, cholesterol, fasting glycemia, and musculoskeletal complaints were compared to the values of the last employment check-up. Results: After an average follow-up period of 11 years, BMI increased from 27.69 (SD = 4.68) to 30.06 (SD = 5.2) (p < 0.0001), cholesterol from 201.7 (SD = 39.87) to 212.62 (SD = 42.51), (p = 0.04). The number of cases of high blood pressure (25 to 56, p < 0.0001) and musculoskeletal complaints increased from 3 initial cases to 26 cases of neck pain (p = 0.07), from 2 to 49 cases of dorsal pain (p = 0.02), and from 18 to 59 cases of lumbar pain (p < 0.0001). High blood pressure and low back pain were significantly correlated with tenure, independent of other factors. Conclusions: As tenure is important in the development of cardiovascular and musculoskeletal diseases, specific interventions should be developed in the early stages of the drivers’ career. Full article

Climate change, the consequences of which have been more intense than ever in the last few decades, makes the need for sustainable transportation even more imperative. The promotion of public transportation and the discouragement of private car use are among the main priorities of sustainable transport planning in modern urban areas. However, the selection of the most appropriate transport project, apart from significant opportunities, is also accompanied by significant challenges, especially under the demand of compromising—often conflicting—social, environmental, and economic criteria, as well as different stakeholders’ interests. The aim of the present paper is to provide decision analysts and policy-makers with a decision-support tool for the prioritization and optimum selection of public transport projects for an urban area within the framework of sustainability. For this purpose, a comprehensive inventory of criteria for the evaluation of urban public transport systems (alternatives), along with a standardized table with the relevant performance of the most common alternatives (i.e., metro, tram, monorail, and BRT) are provided based on international literature review. A multi-criteria decision-aiding methodology based on TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), allowing for the direct exclusion of an alternative not meeting certain “binding” criteria from further evaluation, thus saving time, effort and cost, taking into account different stakeholders’ interests and preferences, as well as the particularities and special characteristics of the study area, is then proposed and tested through a theoretical case study. Full article

This paper explores the potential of public webcams as a source of data for transport research. Eight different open-source object detection models were tested on three publicly accessible webcams located in the city of Brunswick, Germany. Fifteen images at different lighting conditions (bright light, dusk, and night) were selected from each webcam and manually labelled with regard to the following six categories: cars, persons, bicycles, trucks, trams, and buses. The manual counts in these six categories were then compared to the number of counts found by the object detection models. The results show that public webcams constitute a useful source of data for transport research. In bright light conditions, applying out-of-the-box object detection models can yield reliable counts of cars or persons in public squares, streets, and junctions. However, the detection of cars and persons was not reliably accurate at dusk or night. Thus, different object detection models might have to be used to generate accurate counts in different lighting conditions. Furthermore, the object detection models worked less well for identifying trams, buses, bicycles, and trucks. Hence fine-tuning and adapting the models to the specific webcams might be needed to achieve satisfactory results for these four types of traffic participants. Full article

Surface-guided tram systems are increasingly being recognised not only as mobility instruments but also as agents of urban regeneration that reshape spatial and social dynamics. This study evaluates the configurational impact of the Trambesòs tram in Barcelona on accessibility, integration, and urban cohesion within the Levante del Besòs area. A Space Syntax analysis was conducted in UCL DepthmapX for axial map analysis and visual graph analysis within a 500 m radius around each station. Three typologies of intervention (site-specific, articulation axes, and saturation pieces) guided the assessment. This analysis shows that Avinguda Diagonal and Avinguda Meridiana are primary structural corridors, while stations Glòries, Ca l’Aranyó, and Pere IV recorded the highest accessibility and visual openness. The results indicate that targeted interventions have positive impacts on the Space Syntax metrics regardless of their spatial centrality, highlighting the critical role of this diverse intervention typology in shaping the study area’s spatial configuration and influencing a hierarchy of social appropriation and use. It is concluded that the Trambesòs tram and associated urban interventions have jointly enhanced centrality and permeability in key sectors, and specific peripheral enclaves have local functioning. These findings, focused on spatial and morphological patterns, may support future interventions in urban design and mobility planning. Although the analysis centres on spatial configuration, future research may integrate socioeconomic variables to broaden the understanding of regeneration processes. Full article

The article explores the capacity of zero-emission urban public transport (PT) and proposes a standardised method for calculating it across different PT corridors (bus, tram, metro and urban railway). As the European Union (EU) tightens regulations on emissions, targeting also PT, cities are increasingly shifting to electric and hydrogen-powered vehicles. A significant challenge was the lack of a unified methodology to calculate the capacity of zero-emission vehicles, e.g., battery-powered buses carry fewer passengers than diesel ones due to weight restrictions. The article addresses this gap by creating capacity matrices for various vehicle types based on standardised assumptions. Vehicle capacity is calculated based on seating and standing space, with standing passenger space standardised to 0.2 m²/person (E Level of Service). A detailed rolling stock analysis shows how modern designs and floor layouts impact passenger space. Matrices were developed for each mode of transport, showing the number of transported passengers per hour depending on vehicle type and service frequency. The highest capacity is achieved by metro and urban railway systems (up to 95,000+ passengers/hour/direction), while buses offer the lowest (up to 7800 passengers/hour/direction). The authors recommend standardising calculation methods and integrating matrices into planning tools for urban PT corridors. Full article

This article addresses the issue of designing compound curves, i.e., a geometric system consisting of two (or more) circular arcs of different radii, pointing in the same direction and directly connected to each other. Nowadays, compound curves are mainly used on tram lines; they also occur on railways (e.g., on mountain lines), but new ones are generally no longer being built there. Therefore, in relation to railway lines, the aim is to be able to recreate (i.e., model) the existing geometric layout with compound curves, so that it is then possible to correct this layout. An analytical method for designing track geometric systems was used, adapted to the mobile satellite measurement technique, in which calculations are carried out in the appropriate local Cartesian coordinate system. The basis of this system is the symmetrically arranged adjacent main directions of the route, and the beginning is located at the point of intersection of these directions. A number of detailed issues have been clarified and basic characteristic quantities have been determined, and the computational algorithm described in the paper leads to the solution of the problem in a sequential manner. The obtained possibilities of modeling the compound curves are illustrated by the provided calculation example. Full article

Background: The deep inferior epigastric artery perforator (DIEP) flap is currently the most widely used method for autologous breast reconstruction. Its primary advantage over the transverse rectus abdominis muscle (TRAM) flap is the reduction in donor-site morbidity, as it preserves the integrity of the abdominal muscles and motor nerves. Importantly, each patient’s unique vascular anatomy requires an individualized approach to perforator selection and the surgical technique. Objective: We aimed to minimize donor-site morbidity and refine the perforator selection strategy in delayed DIEP flap breast reconstruction using the abdominal perforator exchange (APEX) technique. Materials and Methods: In this study, we prospectively and retrospectively analyzed the use of the APEX technique in patients undergoing delayed DIEP flap breast reconstruction between April 2020 and October 2024. All patients underwent preoperative non-contrast magnetic resonance angiography of the donor area. A total of 106 patients were enrolled and divided into two groups: 34 patients underwent reconstruction using the APEX technique, and 72 patients received standard DIEP flap breast reconstruction. Results: Our study demonstrated a statistically significant increase in operative time, averaging 30.5 min in the APEX group (p < 0.05). There was also a significant difference in the incidence of marginal flap necrosis between the two groups. No cases of myotomy were observed, and motor nerve transection was required in one case. Conclusions: The APEX technique has been shown to be reliable when standard dissection would compromise the neuromuscular anatomy of the abdominal wall without compromising perfusion in the flap. Full article

Background/Objectives: Primary chest wall tumors or malignancies of adjacent organs with chest wall infiltration present a significant challenge for surgical resection and reconstruction. Larger defects involving the sternum, resections in the area of the thoracic apertures, or those near the spine are difficult to reconstruct. The reconstruction has to ensure stability, to prevent paradoxical movements and lung herniation, while also achieving a satisfactory cosmetic result. The “spider web” technique restores chest wall stability by creating a web-like framework made of non-resorbable threads fixed to adjacent bony structures. Additionally, a synthetic mesh is placed over the web construct, and both layers are covered with muscles (local muscles or different types of flaps). In this prospective study, clinical data from patients who underwent surgery using the “spider web” technique were analyzed with respect to chest wall stability, procedure-specific complications, pulmonary function, and patient satisfaction. Methods: A total of 16 patients receiving 18 chest wall resections and reconstructions using the “spider web” technique were followed for at least one year. Chest wall stability and lung function (FEV1 and DLCO) were assessed. Quality of life, cosmetic satisfaction, potential functional impairment, and analgesic consumption were measured using a modified EORTC QLQ-C30 questionnaire. Results: The follow-up period ranged from 12 to 32 months. In all cases, optimal chest wall stability was maintained without impairment of respiratory mechanics. Procedure-specific complications occurred in five cases (27.8%), including seroma (one case), hematoma (two cases), necrosis at the TRAM flap donor site (one case), and mesh infection (one case), all of which were resolved without further complications. Postoperative FEV1 and DLCO were not significantly reduced compared with preoperative values. The global health status score for quality of life was 60 ± 27 points. Nine patients reported being able to ascend at least one floor of stairs without shortness of breath and half of the patients were able to participate in sports activities. One patient required prolonged analgesic medication due to chronic pain. In all cases, patients were satisfied with the cosmetic result. Both 30-day and 90-day mortality were 0%. No local recurrence at the chest wall reconstruction site occurred. Conclusions: The “spider web” technique is a highly suitable method for chest wall reconstruction, allowing covering all types of chest wall defects, regardless of size and location. This cost-effective technique not only provides optimal stability but also good functional results. Full article

Urban noise pollution extends into aquatic environments, influencing underwater ecosystems. This study examines the effectiveness of acoustic indicators in characterizing urban underwater soundscapes using hydrophone recordings. Three indices, the Acoustic Complexity Index (ACI), Acoustic Diversity Index (ADI), and Normalized Difference Soundscape Index (NDSI), were analyzed to assess their ability to distinguish anthropogenic and natural acoustic sources. The results indicate that the ACI tracks urban noise fluctuations, particularly from vehicles and trams, while the ADI primarily reflects transient environmental interferences. The NDSI, while designed to differentiate biophony from anthropogenic noise, proves unreliable in urban underwater settings, often misclassifying noise sources. These findings highlight the limitations of traditional acoustic indices in urban aquatic environments and emphasize the need for refined methods to improve hydrophone data interpretation. Thus, this study aims to understand the acoustic indicators’ interactions with underwater urban noise, which is crucial for enhancing environmental monitoring and noise mitigation strategies. Full article

Proper cellular function hinges on appropriate subcellular protein localization. When cellular proteins become mislocalized, they can accumulate, cause cellular damage, and disrupt many biochemical and cellular processes. Notably, mislocalized protein accumulation and the resulting cytotoxic effects are salient features of neurodegenerative diseases including Alzheimer’s, Parkinson’s disease, and ALS. The detrimental cellular consequences of mislocalized proteins accumulation make it crucial to develop techniques and approaches that counteract this malfunction. Remarkably, a recent study by Ng et al. introduced targeted relocalization-activating molecules (TRAMs) as a novel molecular tool for relocalizing endogenous target proteins to counteract disease-associated mislocalized proteins. The authors developed a quantitative single-cell analysis to evaluate the strength and relocalization capability of TRAMs by coupling a target protein and a shuttle protein. Herein, we briefly highlight and discuss the potential molecular implications for targeted protein relocalization as an effective approach for correcting mislocalized proteins. Full article

Series–series (SS) wireless power transfer (WPT) systems are used in many applications because of their simple circuit structure. Compared with higher-order complex compensation topology, they are suitable for more demanding applications, such as rail trams with high power requirements but limited space for the coupling mechanism. However, the characteristics of their voltage source also put forward higher requirements for the control strategy. Improving the dynamic response performance of an SS compensation WPT system without any communication between the primary and secondary sides is the key issue. This paper proposes an improved variable step-size maximum power point tracking control strategy with the mutual inductance identification. Compared with the conventional P&O control, it can achieve a faster response and more accurate tracking, which are very important to the WPT for rail transit. A method of the mutual inductance identification based on the weight of parameter sensitivity is proposed. Based on the results of the identified mutual inductance, to make the system transfer the maximum power, the duty ratio of the receiver is adjusted to approach the corresponding equivalent load. To deal with the change of the mutual inductance, a condition of terminating the searching process of the maximum power point and re-identifying the mutual inductance is proposed. A simulation and experimental platform is built for verification. The results show that the proposed control strategy can quickly respond to the variation of the mutual inductance and load and achieve accurate maximum power point location, which improves the performance of the SS compensation WPT system. Full article

As global climate change intensifies, the frequency and severity of extreme weather events continue to rise. However, research on semi-outdoor and transitional spaces remains limited, and transportation stations are typically not fully enclosed. Therefore, it is crucial to gain a deeper understanding of the environmental needs of users in these spaces. This study employs machine learning (ML) algorithms and the SHAP (SHapley Additive exPlanations) methodology to identify and rank the critical factors influencing outdoor thermal comfort at tram stations. We collected microclimatic data from tram stations in Guangzhou, along with passenger comfort feedback, to construct a comprehensive dataset encompassing environmental parameters, individual perceptions, and design characteristics. A variety of ML models, including Extreme Gradient Boosting (XGB), Light Gradient Boosting Machine (LightGBM), Categorical Boosting (CatBoost), Random Forest (RF), and K-Nearest Neighbors (KNNs), were trained and validated, with SHAP analysis facilitating the ranking of significant factors. The results indicate that the LightGBM and CatBoost models performed exceptionally well, identifying key determinants such as relative humidity (RH), outdoor air temperature (Ta), mean radiant temperature (Tmrt), clothing insulation (Clo), gender, age, body mass index (BMI), and the location of the space occupied in the past 20 min prior to waiting (SOP20). Notably, the significance of physical parameters surpassed that of physiological and behavioral factors. This research provides clear strategic guidance for urban planners, public transport managers, and designers to enhance thermal comfort at tram stations while offering a data-driven approach to optimizing outdoor spaces and promoting sustainable urban development. Full article

The deployment of large installed power capacities from intermittent renewable energy sources requires balancing to ensure the steady and safe operation of the electrical grid. New methods of energy storage are essential to store excess electrical power when energy is not needed and later use it during high-demand periods, both in the short and long term. Power-to-Gas (P2G) is an energy storage solution that uses electric power produced from renewables to generate gas fuels, such as hydrogen, which can be stored for later use. Hydrogen produced in this manner can be utilized in energy storage systems and in transportation as fuel for cars, trams, trains, or buses. Currently, most hydrogen is produced from fossil fuels. Solid-oxide electrolysis (SOE) offers a method to produce clean hydrogen without harmful emissions, being the most efficient of all electrolysis methods. The objective of this work is to determine the optimal operational parameters of an SOE system, such as lower heating value (LHV)-based efficiency and total input power, based on calculations from a mathematical model. The results are provided for three different operating temperature levels and four different steam utilization ratios. The introductory chapter outlines the motivation and background of this work. The second chapter explains the basics of electrolysis and describes its different types. The third chapter focuses on solid-oxide electrolysis and electrolyzer systems. The fourth chapter details the methodology, including the mathematical formulations and software used for simulations. The fifth chapter presents the results of the calculations with conclusions. The final chapter summarizes this work. Full article