Search Results (102)

The structural design of rail vehicle bodies significantly influences rail vehicle performance, passenger comfort, and operational efficiency. This study presents a comparative analysis of three key concepts of a rail vehicle body, namely a differential, an integral, and a hybrid structure, with a focus on their structural principles, material utilization, and implications for manufacturability and maintenance. Three rail vehicle body variants were developed, each incorporating a low-floor configuration to enhance accessibility and interior layout flexibility. The research explores the suitable placement of technical components such as a power unit and an air-conditioning system, and it evaluates interior layouts aimed at maximizing both passenger capacity and their travelling comfort. Key features, including door and window technologies, thermal comfort solutions, and seating arrangements, are also analyzed. The study emphasizes the importance of compromises between structural stiffness, reparability, production complexity, and passenger-oriented design considerations. A part of the research includes a proposal of three variants of a rail vehicle body frame, together with their strength analysis by means of the finite element method. These analyses identified that the maximal permissible stresses for the individual versions of the frame were not exceeded. Findings contribute to the development of more efficient, accessible, and sustainable regional passenger rail vehicles. Full article

The evaluation of climate change effects on airport infrastructures is important to maintain safety and flexibility in air travel operations. Airports are particularly vulnerable to extreme weather events and temperature fluctuations, which can disrupt operations, compromise passenger safety, and cause economic losses. Issues such as flooded runways and the disruption of power supplies highlight the need for strong adaptation strategies. The study focuses on the application of the high-resolution regional model COSMO-CLM to assess climate change impacts on Roma Fiumicino airport (Italy) under the IPCC RCP8.5 scenario. The complex topography of Italy requires fine-scale simulation to catch localized climate dynamics. By employing advanced statistical methods, such as fractal analysis, this research aims to increase an understanding of climate change and improve the model prediction capability. The findings provide valuable insights for designing resilient airport infrastructures and updating operational protocols in view of evolving climate risks. A consistent increase in daily temperatures is projected, along with a modest positive trend in annual precipitation. The use of advanced statistical methods revealed insights into the fractal dimensions and frequency components of climate variables, showing an increasing complexity and variability of future climatic patterns. Full article

Diesel particulate matter—primarily ultrafine particles (UFPs), defined as particles smaller than 0.1 µm—are released by diesel-powered vehicles, especially those used in heavy-duty hauling. While much of the existing research on traffic-related air pollution focuses on urban environments, limited attention has been paid to how complex topography influences the concentration of UFPs, particularly in areas with significant truck traffic. With a focus on Morgantown, West Virginia, an area distinguished by a steep topography, this study investigates how travel over two different terrain conditions affects UFP concentrations close to roadways. Specifically, we sought to determine if the truck count taken from simultaneous video evidence could be used as a surrogate for varying topography in determining the concentration of UFPs. This study shows that “TRUCK COUNT” and “TRUCK SPEED” have a linear relationship and yield a possible surrogate measure of the lung dose of UFP number concentration. Our results demonstrate a statistically significant (p < 0.1) linear relationship between truck count and UFP number concentration (R = 0.77 and 0.40), validating truck count along with truck speed as a medium effect surrogate for estimating near-road UFP exposure. Dose estimation using the Multiple-Path Particle Dosimetry (MPPD) model further revealed that approximately 30% of inhaled UFPs are deposited in the alveolar region, underscoring the public health relevance of this exposure pathway in topographically complex areas. This method ultimately awaits comparison with health effects to determine its true potential as a useful exposure metric. Full article

One of the challenges of our age is climate change and the ways in which it affects the Earth’s global ecosystem. To face the problems linked to such an issue, the international community has defined actions aimed at the reduction in greenhouse gas emissions in several sectors, including the aviation industry, which has been requested to mitigate its environmental impact. Conventional aircraft propulsion systems depend on fossil fuels, significantly contributing to global carbon emissions. For this reason, innovative propulsion technologies are needed to reduce aviation’s impact on the environment. Electric propulsion has emerged as a promising solution among the several innovative technologies introduced to face climate change challenges. It offers, in fact, a pathway to more sustainable air travel by eliminating direct greenhouse gas emissions, enhancing energy efficiency. Unfortunately, integrating electric motors into aircraft is currently a big challenge, primarily due to thermal management-related issues. Efficient heat dissipation is crucial to maintain optimal performance, reliability, and safety of the electric motor, but aeronautic applications are highly demanding in terms of power, so ad hoc Thermal Management Systems (TMSs) must be developed. The present paper explores the design and optimization of a TMS tailored for a megawatt electric motor in aviation, suitable for regional aircraft (~80 pax). The proposed system relies on coolant oil injected through a hollow shaft and radial tubes to directly reach hot spots and ensure effective heat distribution inside the permanent magnet cavity. The goal of this paper is to demonstrate how advanced TMS strategies can enhance operational efficiency and extend the lifespan of electric motors for aeronautic applications. The effectiveness of the radial tube configuration is assessed by means of advanced Computational Fluid Dynamics (CFD) analysis with the aim of verifying that the proposed design is able to maintain system thermal stability and prevent its overheating. Full article

The threats posed by Persistent Organic Pollutants (POPs) impact food safety and, by implication, food security in the polar regions. POPs tend to persist in the environment and the fatty tissues of animals, thereby constituting long-term contamination. Due to the cold climate and geography of these polar regions, they create a sink for these pollutants, which travel from their source of production and accumulate in food chains, resulting in health risks to the ecosystem, animals, and humans of the Arctic and Antarctica. In this paper, we draw attention to the threats posed by POPs and how they can lead to food insecurity, negatively affecting health due to unsafe traditional foods. A narrative synthesis methodology was employed, systematically analyzing historical data, activities, and research trends on POP contamination in polar ecosystems. We also highlight resilience promoted by Arctic governance, with a focus on how the issues of POPs became an international matter from the 1970s, with three United Nations (UN) conventions: the UN-Environment Stockholm Convention on Persistent Organic Pollutants, the UN Minamata Convention on mercury, and the UN-ECE Convention on Long-range Transboundary Air Pollution. These conventions led to the start of several monitoring activities in the polar regions, transforming the POPs into a global topic. We also consider the intertwined effect of climate change on POPs. Additionally, the human rights paradigm in relation to food security and sovereignty for polar communities is explored. Strengthening the resilience of communities in the polar regions requires recognition of these nutritious traditional foods as an aspect of cultural identity that must be safe and easily accessible. We focus on developments, improvements, the role of international cooperation, and frameworks to assist in research and regulations. Furthermore, establishing systems that engage local communities to consistently monitor POPs regularly will lead to a better understanding of these threats. Ultimately, this narrative provides a look into the past and current research of POPs and their monitoring in the polar regions. Full article

Modern cities are facing increasing challenges such as traffic congestion, high energy consumption, and poor air quality, making rail transit systems, known for their high capacity and low emissions, essential components of sustainable urban infrastructure. While numerous studies have examined how the built environment impacts transit ridership, the complex interactions among these factors warrant further investigation. Recent advancements in the reasoning capabilities of large language models (LLMs) offer a robust methodological foundation for analyzing the complex joint influence of multiple built environment factors. LLMs not only can comprehend the physical meaning of variables but also exhibit strong non-linear modeling and logical reasoning capabilities. This study introduces an LLM-based framework to examine how built environment factors and station characteristics shape the transit ridership dynamics by utilizing DeepSeek-R1. We develop a 4D + N variable system for a more nuanced description of the built environment of the station area which includes density, diversity, design, destination accessibility, and station characteristics, leveraging multi-source data such as points of interest (POIs), road network data, housing prices, and population data. Then, the proposed approach is validated using data from Qingdao, China, examining both single-factor and multi-factor effects on transit peak-hour ridership at the macro level (across all stations) and the meso level (specific station types). First, the variables that have a substantial effect on peak-hour transit ridership at both the macro and meso levels are discussed. Second, key and latent factor combinations are identified. Notably, some factors may appear to have limited importance at the macro level, yet they can substantially influence the peak-hour ridership when interacting with other factors. Our findings enable policymakers to formulate a balanced mix of soft and hard policies, such as integrating a flexitime policy with enhancements in active travel infrastructure to increase the attractiveness of public transit. The proposed analytical framework is adaptable across regions and applicable to various transportation modes. These insights can guide transportation managers and policymakers while optimizing Transit-Oriented Development (TOD) strategies to enhance the sustainability of the entire transportation system. Full article

The process of ultrasonic atomization involves a series of dynamic/topological deformations of free surface, though not always, of a bulk liquid (initially) below the air. This study focuses on such dynamic interfacial alterations realized by changing some acousto-related operating conditions, including ultrasound excitation frequency, acoustic strength or input power density, and the presence/absence of a “stabilizing” nozzle. High-speed, high-resolution imaging made it possible to qualitatively identify four representative transitions/demarcations: (1) the onset of a protrusion on otherwise flat free surface; (2) the appearance of undulation along the growing protuberance; (3) the triggering of emanating beads fountain out of this foundation-like region; and (4) the induction of droplets bursting and/or mist spreading. Quantitatively examined were the two-parameters specifications—on the degrees as well as induction—of the periodicity in the protrusion-surface and beads-fountain oscillations, detected over wider ranges of driving/excitation frequency (0.43–3.0 MHz) and input power density (0.5–10 W/${\mathrm{c}\mathrm{m}}^2$) applied to the ultrasound transducer of flat surface on which the nozzle was either mounted or not. The resulting time sequence of images processed for the extended operating ranges, regarding the fountain structure pertaining, in particular, to recurring beads, confirms the wave-associated nature, i.e., their size “scalability” to the ultrasound wavelength, predictable from the traveling wave relationship. The thresholds in acoustic conditions for each of the four transition states of the fountain structure have been identified—notably, the onset of plausible “bifurcation” in the chain-beads’ diameter below a critical excitation frequency. Full article

Aviation emissions significantly impact air quality, contributing to environmental degradation and public health risks. This study aims to assess the impact of aviation-related emissions on air quality at Alexandroupolis Regional Airport, Greece, and evaluate the role of meteorological factors in pollution dispersion. Using machine learning models, we analyzed emissions data, including CO₂, NOx, CO, HC, SOx, PM_2.5, fuel consumption, and meteorological parameters from 2019–2020. Results indicate that NOx and CO₂ emissions showed the highest correlation with air traffic volume and fuel consumption (R = 0.63 and 0.67, respectively). Bayesian Linear Regression and Linear Regression emerged as the most accurate models, achieving an R² value of 0.96 and 0.97, respectively, for predicting PM_2.5 concentrations. Meteorological factors had a moderate influence, with precipitation negatively correlated with PM_2.5 (−0.03), while temperature and wind speed showed limited effects on emissions. A significant decline in aviation emissions was observed in 2020, with CO₂ emissions decreasing by 28.1%, NOx by 26.5%, and PM_2.5 by 35.4% compared to 2019, reflecting the impact of COVID-19 travel restrictions. Carbon dioxide had the most extensive percentage distribution, accounting for 75.5% of total emissions, followed by fuels, which accounted for 24%, and the remaining pollutants, such as NOx, CO, HC, SOx, and PM_2.5, had more minor impacts. These findings highlight the need for optimized air quality management at regional airports, integrating machine learning for predictive monitoring and supporting policy interventions to mitigate aviation-related pollution. Full article

This paper analyses the asymmetric effects of air transport on CO₂ emissions from transport in the Gulf Cooperation Council countries. The analysis utilises CO₂ emissions from transport, which are more relevant and critical for assessing the environmental performance of transport. Moreover, the current paper has examined this relationship with further macroeconomic variables within the Gulf Cooperation Council context. This paper uses a significant sample of six nations and spans an extensive period from 1990 to 2020. The second-generation Auto Regressive Distributed Lag model was applied to enable the examination of regional heterogeneity and the assessment of transport’s effect on CO₂ emissions across several countries. The intensity of environmental degradation may differ among the Gulf Cooperation Council countries, hence, environmental policies should include trends in transport emissions. Long-term estimates based on the ARDL technique suggest that energy consumption, economic growth, and air travel exacerbate the ratio of CO₂ emissions from transport and pollution levels. The results can be utilised to develop a transport-related environmental strategy that aligns with the sustainable development goals. The paper proposes strategies for achieving a sustainable environment and energy future. Full article

Road traffic infrastructure construction is widely regarded as a solution to urban congestion and air pollution. Given the frequent use of non-highway roads for inter-city travel, it is plausible that such infrastructure projects could also improve air quality in neighboring regions. However, the spatial spillover effects of these projects on air pollution remain underexplored. This paper investigates the spatial impacts of road traffic infrastructure construction on urban air pollution. Using a spatial panel regression model, we analyze data from 273 cities in a period spanning 2008 to 2021. Our findings show that road infrastructure construction significantly reduces local air pollution, with results robust to concerns about endogeneity. Furthermore, we identify notable spatial spillover effects, primarily concentrated in adjacent cities. These findings suggest that the accessibility between central cities and their neighboring areas plays a critical role in shaping traffic patterns, air quality, and sustainable urban development. As a result, coordinated regional planning for road infrastructure could serve as an effective strategy to mitigate urban air pollution and promote sustainable growth. Full article

Problem: Basketball and football teams in Türkiye have the capacity to travel hundreds of kilometres for league matches. In general, such major leagues and leading teams travelling from Türkiye have not been sufficiently researched in the context of Türkiye’s leading leagues and teams. In this context, the aim of this study is to assess and compare the carbon footprint of the transport activities of basketball and football teams in Türkiye for their home and away matches for the 2023–2024 season. Methods: The research is based on EN 16258 and ICAO carbon emissions methodologies. This study aims to calculate and compare the carbon footprint of different transport methods, including bus and plane, used by five basketball and football teams in Türkiye. Results: The findings show that there are significant differences between the teams in terms of travelling distances and carbon footprints. Trabzonspor from the Black Sea region released the highest CO₂ emissions from air travel with a total of 91,667.1 kgCO_2e, while Fenerbahçe Beko had the lowest CO₂ emissions with 5316.72 kgCO_2e. In terms of bus travel, Gaziantep FK led the CO₂ emissions with 4356.45 kgCO_2e, while Türk Telekom was the team with the lowest CO₂ emissions with 1233.225 kgCO_2e. The findings also reveal a notable difference in the number of trees teams need to plant to offset their carbon emissions. Because of their travel patterns, Antalyaspor would need to plant 3481 trees, whereas Fenerbahçe Beko would only need to plant 348 trees. Conclusions: Air travel is emerging as the dominant source of CO₂ emissions and has a greater impact on the environmental impact of teams that rely heavily on airplanes. In this study, the league structure and duration play a critical role in shaping the carbon footprint of sports teams. The football season, which is longer compared to basketball, requires more frequent travel, especially for teams in more remote regions, resulting in higher carbon emissions than basketball. The dominance of Marmara region teams in basketball has a negative impact on the carbon footprint since these teams generally have shorter travel distances. Full article

The connected and automated vehicles (CAVs) that are expected to be increasingly common on U.S. roads in the coming decades offer potential benefits in safety, efficiency, and mobility; they also raise concerns related to equity, access, and impacts on land use and travel behavior, as well as questions about extensive data requirements for CAVs to communicate with other vehicles and the environment in order to operate safely and efficiently. We report on interviews with North Carolina transportation experts about CAVs and their implications for sustainable transportation that serves all travelers with affordable, safe, and dignified mobility that also produces fewer environment impacts (emissions to air, water, and land; resource consumption; land use changes). The data reveal great interest among transportation professionals about a CAV transition, but a lack of consensus on the state of play and necessary next steps. Concerns include impacts on planning practice; implications for land use, equity, and safety; and data security and privacy. The findings suggest that local, regional, and state agencies would benefit from clear technical guidance on how to prepare for CAVs and to engage with the public, given high interest about a coming CAV transition. Intense data requirements for CAVs and associated infrastructure, as well as the regulatory and policy tools that will be required, raise concerns about threats to data safety and security and argue for proactive action. Full article

High-speed rail is a high-standard railway system, which allows trains to operate at high speed. The railway play a crucial role in connecting urban agglomerations, which represents the highest form of spatial organization in the mature stage of urban development, bringing together cities of various natures, types, and scales in specific regions. This paper explores the impacts of high-speed rail and its expansion on industrial concentration and macroeconomic conditions in the period of 2000 to 2019. We use a well-known transportation policy as a natural experiment, utilizing geographic distance data to study the effects of high-speed rail and its expansion on industrial concentration and macroeconomic conditions in urban agglomerations. The results show that high-speed rail increases industrial concentration but leads to a reduction in macroeconomic conditions. Unlike previous studies in this field, we use distance variables to analyze how the expansion of high-speed rail affects macroeconomic conditions and industrial concentration through location advantages. The impacts of high-speed rails vary across urban and non-urban agglomeration cities, resource-based and non-resource-based cities, large and small cities, and eastern, central, and western regions. Our results are robust to the shocks from the global financial crisis, time lags, different distance dummy variables, dependent variables, and endogeneity issues. This study regards the opening up of high-speed rail as both improving air quality and reducing carbon emissions through substituting for urban and aviation transport. Compared to traditional transport methods such as urban and air travel, the efficiency and environmental benefits of high-speed rail make it an important method for reducing greenhouse gas emissions. Consequently, the expansion of high-speed rail could support both economic development and environmental concerns, and it is playing a crucial role in transportation selection for advancing low-carbon economic goals. Full article

The aims of this study are to analyze the tourism and air-transport industries in Africa and determine how African governments could improve the safety of tourists and local communities in this region to improve resident quality of life and tourism demand. Indeed, this study tries to improve African people’s lives through the tourism and travel sectors so that they can thrive in terms of their quality of life and happiness. The findings of the current study reveal that Morocco, Egypt, South Africa, and Tunisia are the most visited countries by international tourists; in fact, these four countries are the ones that generated the most income from international tourism in the period analyzed. Moreover, the results suggest that the tourism and air-transport industries in Africa could improve national economies, infrastructure, and resident quality of life thanks to international tourism receipts and increasing security levels around travel and tourism activities. Obviously, the tourism industry cannot be developed when there is constant insecurity, terrorism, and perpetual armed conflicts, as is the case in Nigeria, Somalia, DR Congo, Libya, Mali, and Cameroon, among many others. Security is the most important factor for a tourist destination because the safety and security of residents and tourists are the primary factors affecting tourism growth. The novelty of this research resides in its willingness to improve African people’s quality of life through air-transport and tourism activities, providing security guarantees for tourist and resident safety. This manuscript also contributes to enhancing and bootstrapping the literature on security in the travel and tourism sectors industry, particularly in Africa, where security is a priority more than a necessity. Full article

The transportation of patients in emergency medical situations, particularly in rural areas, often faces significant challenges due to long travel distances and limited access to healthcare facilities. These challenges can result in critical delays in medical care, adversely affecting patient outcomes. Addressing this issue is essential for improving survival rates and health outcomes in underserved regions. This study explored the potential of advanced air mobility to enhance emergency medical services by reducing patient transport times through the strategic placement of vertiports. Using North Dakota as a case study, the research developed a GIS-based optimization workflow to identify optimal vertiport locations that maximize time savings. The study highlighted the benefits of strategic vertiport placement at existing airports and hospital heliports to minimize community disruption and leverage underutilized infrastructure. A key finding was that the optimized mixed-mode routes could reduce patient transport times by up to 21.8 min compared with drive-only routes, significantly impacting emergency response efficiency. Additionally, the study revealed that more than 45% of the populated areas experienced reduced ground travel times due to the integration of vertiports, highlighting the strategic importance of vertiport placement in optimizing emergency medical services. The research also demonstrated the replicability of the GIS-based optimization model for other regions, offering valuable insights for policymakers and stakeholders in enhancing EMS through advanced air mobility solutions. Full article