Search Results (12,782)

As the market of perishable goods in China continues to expand, reducing quality loss during transportation has become an urgent issue for the industry. Multimodal transport, as a key approach to optimizing the transportation structure and lowering logistics costs, has been increasingly adopted in practice. However, multimodal transport involves multiple transfers, and continuous vibration from transportation equipment throughout the transport process, together with impacts during transfer operations, can easily increase the loss of perishable goods, making it highly significant in practice to consider vibration loss during transportation in route planning. Since different transportation equipment generates different levels of vibration acceleration, this study considers the vibration losses caused by road, rail, and air transport. A bi-objective route optimization model for fresh produce multimodal transport is established, aiming to minimize total cost while maximizing product quality satisfaction. A hybrid algorithm combining an improved Strength Pareto Evolutionary Algorithm and a multi-objective adaptive large neighborhood search algorithm is designed to solve the model. The effectiveness of the model and algorithm is verified through case analysis, followed by sensitivity analysis on different time-sensitive factors of vibration damage and vibration acceleration. The results show that, compared with the multi-objective adaptive large neighborhood search algorithm and the non-dominated sorting genetic algorithm, the proposed algorithm can obtain solutions with lower total costs or higher product quality satisfaction. The minimum total cost of the multimodal transport scheme obtained by the proposed algorithm is reduced by 0.27% and 2.4%, respectively, compared with the multi-objective adaptive large neighborhood search algorithm and the non-dominated sorting genetic algorithm, while the maximum satisfaction is increased by 2.1% and 0.35%, respectively. Full article

Amid the well-researched negative effects of road congestion and increased private car use, there is a need for more sustainable modes of transport. The literature points towards trains as being a vital part of the solution to the current problems, but their success depends on a number of variables, especially when it comes to the main railway stations in the largest cities. The first goal of this study was to identify the relationship between passenger numbers at major railway stations in Poland and selected parameters characterizing public transport services; the second was to assess the usefulness of the NOAH (Nest of Apes Heuristic) method for data analysis. In Poland, the number of major transfer hubs is limited, and there is a lack of an existing method allowing comparison of variables in such small datasets in a way that infers statistical significance. This is a research gap that the authors aimed to address using the NOAH algorithm combined with an analysis of regression. The initial dataset had been successfully expanded in a way that dependencies could be observed, with both goals being met. Passenger numbers relied most on the number of trains departing at each station daily, while walking distance during transfers impacted that number most negatively. The results point towards other variables influencing the passenger numbers, which were not considered in this study but could form the basis of further research. The utilized method could also be applied to a different group of cities, and in other countries. Additionally, the study added to the development of the NOAH algorithm itself, improving the method. Full article

Donkeys and horses diverged approximately 4 million years ago and exhibit substantial genetic, chromosomal, and physiologic differences. Although mostly studied in horses, metabolic syndrome represents a broader metabolic dysfunction with systemic consequences, such as obesity and laminitis, that can impact the quality of life of equids. This review summarizes the current knowledge of glucose and insulin regulation in healthy horses and donkeys and examines the pathophysiology of equine metabolic syndrome (EMS) in comparison with donkey metabolic syndrome (DMS), including insulin dysregulation, impaired glucose transport, adipose tissue dysfunction, and emerging evidence of systemic meta-inflammation and oxidative stress. Compared with horses, donkeys demonstrate distinct patterns of adipose deposition, different metabolic profiles, and altered glucose and insulin dynamics following oral soluble carbohydrate intake. While our understanding of donkey medicine has expanded in recent years, gaps in knowledge remain regarding mechanistic insights into glucose metabolism and dysregulation in donkeys. Finally, we evaluate current and emerging therapeutic strategies, including dietary management, exercise, nutraceuticals, and pharmacologic interventions such as metformin and sodium–glucose cotransporter 2 inhibitors (SGLT2is). While these therapeutic approaches have demonstrated efficacy in horses, evidence in donkeys remains extremely limited. This highlights a critical need for species-specific research to elucidate the pathophysiological mechanisms and optimize therapeutic strategies for donkeys. Full article

With urban rail transit networks gradually entering a mature stage of development, whether newly added lines and stations can still improve local labour market outcomes remains an important question in transport planning and urban regeneration research. This paper examines light rail transit expansion in three mature UK cities: Manchester, Sheffield, and Nottingham. Using MSOA-level panel data from 2013 to 2024, this study applies a Difference-in-Differences (DID) approach to evaluate the impact of light rail transit expansion on local labour market vulnerability. MSOAs intersecting with the 500-m buffer zones of newly opened light rail stations are defined as the treatment group, while MSOAs not directly affected by light rail expansion are used as the control group. The Claimant Count is used as a proxy for welfare dependency and labour-market vulnerability. The results show that light rail transit expansion significantly reduces the Claimant Count in treated areas, with an estimated decline of approximately 7.52–7.56%. This finding remains robust after adding demographic, socio-economic, and built environment controls, applying MSOA-level clustered standard errors, implementing PSM-DID, and conducting placebo tests. Mechanism analysis further shows that light rail expansion is associated with changes in the functional structure of station areas, including increases in overall POI density and service-oriented facilities, while manufacturing and production-related facilities decline. These findings suggest that light rail expansion may reduce local unemployment-related welfare dependency by improving employment accessibility, alleviating spatial mismatch, and promoting service-sector agglomeration. This study provides new empirical evidence on the socio-economic effects of light rail expansion in mature UK cities. Full article

The transition to lower-clinker binders in heavy precast concrete is constrained by the need to combine rapid production cycles, high early-age strength, self-compacting performance, durability and measurable environmental benefits. The scientific gap addressed in this study is the limited integrated evidence comparing these criteria under conditions that are representative of industrial heavy precast production, particularly for CEM II/A-S 52.5 R and CEM II/B-V 42.5 R. Four concretes were assessed: CEM I 52.5 R, CEM II/A-S 52.5 R, CEM II/B-V 42.5 R, and a 50:50 CEM I/CEM II/B-V binder. The experimental programme included slump-flow, a plant-specific 600 mm flow-time indicator, compressive strength development, hardened density, water absorption, water penetration under pressure and freeze–thaw resistance. Environmental performance was evaluated using the manufacturers Environmental Product Declarations (EPDs) for the cement component within a cradle-to-gate boundary. All mixtures corresponded to at least strength class C50/60 at 28 days, while CEM I, CEM II/A-S and the 50:50 blend corresponded to C55/67. CEM II/A-S reduced water absorption from 5.49% to 4.29% and water penetration from approximately 61 to 23 mm relative to CEM I, but its freeze–thaw strength loss was 26.80% compared with 4.50% for CEM I. CEM II/B-V provided the lowest cement-related GWP, approximately 154 kg CO₂-eq/m³, about 25% below CEM I, whereas the 50:50 blend reduced this indicator by approximately 12% while achieving the highest 28-day compressive strength (approximately 78 MPa). The results show that cement selection for heavy precast concrete cannot be based on clinker content or strength alone. CEM II/A-S offered the most balanced technological and transport-property performance, whereas CEM II/B-V offered the greatest GWP reduction but requires consideration of its lower strength class and slower early-age development. Long-term durability and full life-cycle impacts remain to be verified. Full article

To investigate photosynthetic physiological response mechanisms of rice (Oryza sativa L.) seedling leaves under drought stress, a pot experiment with controlled watering was conducted. Four treatments were applied—control (CK), mild drought (LD), moderate drought (MD), and severe drought (SD)—to four cultivars (H17B7, HY3015, LH1H, WNSM) at seedling stage. The results showed that, after drought stress, the morphological indicators and chlorophyll content of the four rice cultivars all showed decreased trend, but a compensatory effect appeared in some varieties under the LD treatment. As drought intensified, the chlorophyll fluorescence induction kinetics (OJIP) curves’ polyphasic rise was inhibited, mainly affecting the J-I and I-P phases. Under SD, the P-phase declined by 44.36%, 36.75%, 32.61% and 50.62% compared with CK, and positive L-band, K-band, and J-band. Chlorophyll fluorescence parameters showed dynamic changes. Most chlorophyll fluorescence parameters (e.g., F_v/F_m) decreased, whereas TR_o/CS_o and DI_o/CS_o exhibited cultivar-dependent variations. Principal components of the chlorophyll fluorescence parameters in seedling leaves of the four rice cultivars showed differences and were clearly distinguished. Plant height, chlorophyll content, etc., are highly significantly positively correlated with F_o, DI_o/CS_o, etc., as well as chlorophyll content with DI_o/CS_o. The OJIP/JIP-test responses suggest impairment of the PQ pool and downstream electron transport, with the extent of damage varying among cultivars. Full article

The National Transport Safety Board found that Wheels-Up Landing was the second highest defining event for aircraft accidents from 2008 to 2022. The increasing push for sustainable propulsion and accompanying novel airframe architectures present new integration and safety challenges for aircraft design and development, among which is the structural integrity and crashworthiness of the aircraft under such extreme events. This paper examines the regulations and design requirements governing aircraft emergency Wheels-Up Landing scenarios, emphasising their implications for aircraft safety and structural integrity. It consolidates standards from aviation authorities, such as the FAA and EASA, which identify and define key requirements relating to occupant safety and fire prevention and protection during such events. The paper then considers the Wheels-Up Landing scenario and its design requirements within the context of future novel aircraft employing sustainable propulsion systems, from higher bypass turbofan to electric- and hydrogen-based technologies. The unique characteristics and challenges of these emerging propulsion technologies are described, highlighting how alternative structural configurations, weight distributions and powerplant architectures may influence the aircraft response under a Wheels-Up Landing event. Finally, an exploration of predictive modelling strategies and methods currently used in Wheels-Up Landing analysis was conducted. While reviewing the breadth of accurate, high-fidelity modelling methods targeting fuselage impact, it also highlighted the gap in both considering the increasingly relevant and frequent powerplant impact scenarios, and the provision of lightweight modelling approaches necessary to rapidly and adequately address the emergency Wheels-Up Landing response early in the aircraft design process. Full article

One of the most common dynamic phenomena occurring in surface waters is the transport of soluble and insoluble contaminants from various sources, such as industry and agriculture. A key concern associated with this transport is the rate at which contaminants migrate downstream to a point of interest, as well as their overall impact. In order to characterize the transport of contaminants in a body of surface water (in this case, a river), this study applied a one-dimensional advection–dispersion model that incorporated transient storage effects. This enabled the characterization of nutrient transport considering varying flow velocities along the river’s course. Adopting a more comprehensive, systemic approach enables a more holistic environmental application and facilitates parameterization of a considerably larger river than in previous case studies. The model’s innovation lies in using routinely monitored water quality constituents to evaluate their ability to inform the characterization of mixing conditions and solute transport in surface water streams. Its dynamic nature provides a reasonable approximation of the real system’s behavior over time. Finally, for management purposes, the proposed model can be replicated without extensive changes to its fundamental structure. Full article

The results of the experiments on the transport process of fluid flow through a pipeline under temperature gradient conditions between the internal and external environments, and on continuous gas generation at the contact boundary of the transported media, are presented in this paper. The test results showed that under non-isothermal flow conditions, a slippage effect will impact flow velocity and pressure, as well as the temperature distributions in variable cross-section pipes. Laboratory experiments were conducted in order to study the effects of the gas nucleus at the pipe walls on the hydrodynamic characteristics of the fluid flow. It is shown that the throughput capacity of the pipe is affected by the temperature difference between the oil and the pipe walls. The test results also demonstrated that at certain temperature gradients on the border layer, the pipe’s capacity reaches its maximum value. Quantitatively, the hydroconductivity of Q/ΔP increased from about 1.45 × 10⁻⁵ m³/(s·MPa) under relatively isothermal conditions to a maximum value of approximately 2.04 × 10⁻⁵ m³/(s·MPa) with a temperature difference in the oil–pipe-wall zone of about 3–5 K, which corresponds to an increase of about 41%. With a further increase in the temperature difference, the hydroconductivity decreased to about 1.64 × 10⁻⁵ m³/(s·MPa) at 10 K and then stabilized in the range of (1.60–1.64) × 10⁻⁵ m³/(s·MPa). This non-monotonic behavior is explained by the temperature-induced release of gas and the formation of a gas-saturated wall zone, which initially reduces the effective resistance of the wall and creates an apparent sliding effect. At high temperature differences, gas accumulation, thermal insulation of the wall area and two-phase flow disturbances limit this effect, which leads to the decrease and subsequent stabilization of the pipe capacity. Full article

Marine concrete structures are subjected to multiple aggressive ions that react with hydration products, driving dynamic phase evolution and altering ion transport pathways. This study develops a multi-scale lattice diffusion–reaction coupled framework grounded in a microstructural evolution model, incorporating a simplified analytical correction for the electrical double layer (EDL) effect. Validation against Poisson–Boltzmann numerical solutions across a pore size range of 1.5–50 nm confirms that the mean relative errors for monovalent, divalent, and trivalent ions remain within 10%. The phase evolution of cement paste under single-ion attack was simulated, and its impact on ion transport performance under multi-ion coupled ingress was systematically investigated. Under multi-ion attack, solid phases exhibit a highly ordered spatial zonation. Chloride ions completely displace monosulfate, forming a Friedel’s salt-enriched zone. Meanwhile, directly penetrating external sulfate generates a pronounced surface ettringite peak, while sulfate released from monosulfate decomposition in the Friedel’s salt zone induces secondary ettringite precipitation deeper within the material, producing a characteristic double-step ettringite distribution. A cracking criterion based on the critical capillary pore filling fraction captures the transition from pore filling to microcracking, yielding a three-zone profile for the relative diffusion coefficient. At 500 days of exposure, crystallization-induced microcracking triggers a more than 7-fold increase in surface relative diffusivity ($w/c$ = 0.35). Furthermore, at 250 days, once cracking initiates, low water-to-cement ratio ($w/c$ = 0.3) matrices display a higher relative diffusivity amplification factor of approximately 9, compared to approximately 6 for high water-to-cement ratio ($w/c$ = 0.4) matrices. The established framework provides a quantitative tool for assessing the durability of concrete structures under complex chemical attack environments. Full article

Efficient wood logistics is essential for a sustainable wood supply chain. In Poland, mounting symptoms of inefficiency highlight the need for a systematic and comprehensive performance assessment across the entire supply chain. Previous studies have predominantly focused on individual supply chain segments or specific stakeholder perspectives, but a comprehensive evaluation of wood supply chain efficiency in Poland remains unrealized. The study aimed to assess the efficiency of the timber supply chain at the Regional Directorate of State Forests level. The analysis encompasses the entire process from harvest planning to delivery to wood processing plants. The business-as-usual scenario derived from historical data is compared with improvement scenarios using a simulation–based optimization approach implemented in ArcGIS Pro 3.4.0. The scenarios are structured according to their decision-making impact: strategic logistics, tactical infrastructure, and operational routines. In total, 18 scenarios are developed to assess total operational costs, including environmental costs per m³ of timber. This covers harvesting, extraction, and transport across all feasible equipment combinations in Poland. The model’s performance was verified for timber harvesting and skidding. Full article

Anthropogenic greenhouse gases (GHGs) and emissions from maritime transport represent a significant challenge for atmospheric monitoring and control. The Istanbul Strait, characterized by its narrow, winding geography and high traffic density, presents a unique chokepoint where these emissions directly impact local air quality. This study proposes a gas-focused integrated framework that combines Sentinel-5 Precursor (Sentinel-5P) TROPOspheric Monitoring Instrument (TROPOMI) satellite observations with Automatic Identification System (AIS) data to analyze atmospheric trace pollutant time series in the Istanbul Strait during 2025. A bottom-up emission methodology based on the IMO 4th GHG Study was employed, yielding annual gaseous pollutant totals of 213,678 tons of carbon dioxide (CO₂), 5970 tons of nitrogen oxides (NO_x), and 686 tons of sulfur oxides (SO_x). Time-series and cross-correlation analyses demonstrated a quantifiable relationship between AIS-derived NO_x estimates and TROPOMI NO₂ tropospheric column densities (r = 0.76, p < 0.05, n = 12), validating the use of satellite sensors for marine atmospheric monitoring. A decision support system (DSS) proof of concept (PoC) was developed to evaluate emission control scenarios through speed optimization. The results indicate that implementing a 10% speed reduction strategy could reduce CO₂ emissions by 18% (38,462 tons) and generate net economic savings of EUR 3.07 million under the European Union Emissions Trading System (EU ETS) carbon pricing framework. Furthermore, a scenario with a 20% speed reduction resulted in a 35% decrease in CO₂ emissions. The findings underscore the potential of integrating satellite-based gas remote sensing with AIS data, thereby facilitating real-time atmospheric monitoring and strengthening emission control policy enforcement in maritime chokepoints. Full article

Wildfire spread on a large scale is heavily driven by the transport of firebrands, as it leads to short- and long-range spotting. Detailed knowledge of terminal velocity can help predict firebrand transport and therefore overall wildfire spread modelling. The current work evaluates an approach to estimating terminal velocity based on CFD simulations with a detailed firebrand shape and assesses its impact on orientation. For the selected firebrand and simulation setup, a range of terminal velocities of approximately 5 to 11 m/s is calculated. This is based on 352 RANS simulations for one particular detailed firebrand at 11 different orientations and two turbulence models, with varying inlet velocities and two mesh refinements. DES and LES turbulence models are considered as a next step for a detailed comparison with wind tunnel measurements. Full article

Recent efforts to address flooding have explored incorporating flow-reduction capabilities into existing infrastructure. Roadside ditches have historically been viewed as an underutilized component of flood reduction, and a two-stage design has been proposed that modifies a conventional trapezoidal ditch by incorporating bench insets along the main channel. While it is expected that this second stage becomes inundated during storm events, resulting in flow attenuation, the exact impacts of this design are unknown. This study quantified the impact of the two-stage design by modeling a roadside ditch corridor in eastern Iowa. An existing single-stage ditch was converted to a two-stage design, and a HEC-RAS model was constructed to investigate the ditch’s impacts for four design storms (1-year, 2-year, 5-year, and 10-year). In the modeled results, peak flow rates were reduced by 22%, 21%, 7.5%, and 4.3%, respectively, while water volume reductions were near 6%. Maximum velocities throughout the ditch corridor also decreased, with reductions spanning 32% (1-year)–45% (10-year). These results indicate that increased travel times and infiltration associated with the two-stage design provide hydrologic and hydraulic benefits by lessening flood and erosion risk. While further study is needed to verify this behavior through monitoring and modeling at other locations, our findings suggest that two-stage ditches can be a useful best management practice for the transportation community. Full article

The transition toward a circular economy in the mining sector has increased the need for sustainable strategies capable of recovering value from tailings generated during mining activities and supporting the safe closure of tailings dams. The present study evaluates the environmental performance of reverse mining as a circular economy strategy by comparing two iron ore tailings valorization pathways: mineral reprocessing for iron recovery and reuse as aggregates in cementitious composites. A Life Cycle Assessment (LCA), conducted in accordance with ISO 14040 and ISO 14044 standards, was applied using OpenLCA software and primary operational data collected from a full-scale tailings dam decommissioning project in Minas Gerais, Brazil. Environmental impacts were assessed in ten impact categories using the ReCiPe Midpoint methodology, with emphasis on Global Warming Potential (GWP). Reverse-mined tailings presented a GWP of 1.91 kg CO₂ eq/t, substantially lower than conventionally mined iron ore (6.80 kg CO₂ eq/t) and comparable to natural sand (1.88 kg CO₂ eq/t). Mineral reprocessing reduced the GWP associated with iron ore production by approximately 50%, while the reuse of tailings as construction aggregates proved environmentally competitive under suitable transport conditions. These findings demonstrate that reverse mining can support sustainable tailings dam closure by reducing environmental impacts, recovering secondary resources, and advancing circular economy practices in the mining sector through a practical decision-support framework based on primary industrial data. Full article