Search Results (543)

The dynamics of port-Hamiltonian systems is based on energy balance principles (the first law of thermodynamics) embedded in the structure of the model. However, when dealing with thermodynamic subsystems, the second law (entropy production) should also be explicitly taken into account. Several frameworks were developed as extensions to the thermodynamic domain of port-Hamiltonian systems. In our work, we study three of them, namely irreversible port-Hamiltonian systems, entropy-based generalized Hamiltonian systems, and entropy-production-metric-based port-Hamiltonian systems, which represent alternative approaches of selecting the state variables, the storage function, simplicity of physical interpretation, etc. On the example of a simplified lumped-parameter model of a heat exchanger, we study the frameworks in terms of their implementability for an IDA-PBC-like control and the simplicity of using these frameworks for practitioners already familiar with the port-Hamiltonian systems. The comparative study demonstrated the possibility of using each of these approaches to derive IDA-PBC-like thermodynamically consistent control and provided insight into the applicability of each framework for the modeling and control of multiphysics systems with thermodynamic subsystems. Full article

With the surge in global maritime trade of new energy vehicles (NEVs), the roll-on/roll-off (Ro-Ro) shipping market faces a severe supply–demand imbalance, pushing shipping rates to persistently high levels. To tackle this challenge, NEV manufacturers and other automakers have begun establishing their own Ro-Ro fleets, creating an urgent need for optimized operational scheduling of these proprietary fleets. Against this context, this study focuses on optimizing the operational scheduling of automakers’ self-owned Ro-Ro fleets. Under the premise of deterministic automobile export transportation demands, a mixed-integer programming model is developed to minimize total fleet operational costs, with decision variables covering vessel port call sequence/selection, port loading and unloading quantities, and voyage speeds. A genetic algorithm is designed to solve the model, and the effectiveness of the proposed approach is validated through a real-world case study. The results demonstrate that the optimization method generates clear, actionable scheduling schemes for self-owned Ro-Ro fleets, effectively helping automakers refine their maritime logistics strategies for proprietary fleets. This study contributes to the field by focusing on automaker-owned Ro-Ro fleets and filling the research gap in cargo-owner-centric scheduling, providing a practical tool for automakers’ overseas logistics operations. Full article

This study explores the integrated scheduling optimization of coal port operations, addressing the dual challenges of handling efficiency and resource conservation by coordinating equipment scheduling with stockyard spraying operations. Through a systematic analysis of operational processes in coal ports, a mixed-integer linear programming (MILP) model is developed to achieve global optimization while explicitly quantifying water and electricity consumption in spraying operations. To address this complex problem, we propose a novel hybrid algorithm that integrates a micro-evolutionary algorithm (MEA) framework with multi-agent proximal policy optimization (MAPPO), enabling adaptive decision-making for large-scale real-time scheduling. Three specialized agents for crossover, mutation, and neighborhood search achieve collaborative optimization by observing population features as states, selecting evolutionary operators as actions, and receiving composite rewards based on both population improvement and individual contributions. This strategy facilitates adaptive operator selection and optimal evolutionary direction derivation, collectively guiding population evolution toward high-quality solutions. Extensive experiments on ten scaled instances of a real-world coal port confirm the proposed algorithm’s superior performance. Compared with four other standard algorithms, it consistently yields higher hypervolume (HV) values and lower inverted generational distance (IGD) metrics, which collectively demonstrate stronger convergence capability and higher solution quality. Full article

Atmospheric aerosols impact environmental quality and health, requiring accurate quantification. This study employed the PMeye scanning LiDAR, a UV system operating at 355 nm by Raymetrics S.A. for continuous, high-resolution monitoring in two campaigns: May 2024 (Vasilikos Power Station, Cyprus) and June 2024 (Port of Piraeus, Greece). Measurement days with dust presence were selected via AERONET-based aerosol classification and validated using a SKIRON model. A novel horizontal scanning method at 355 nm distinguished dust from anthropogenic emissions. Results showed higher pollution in Cyprus (~500 μg/m³) due to dust and chimney emissions, versus ~150 μg/m³ in Piraeus from dust and ship exhausts. Full article

This study investigates the behavioral determinants of tourists’ selection of ESG-certified hotels by applying association rule mining to 895,962 valid records derived from datasets of the Ministry of Transportation and the Ministry of Environment. Tourists were classified into three groups based on length of stay. The results reveal strong associations between ESG hotel choice and factors such as gender, age, port of entry, transport mode, and arrival city, with prominent patterns including “Kaohsiung Port,” “Age 30–39,” and “Airplane.” This study offers both theoretical contributions and actionable policy implications, advocating data-driven strategies to advance sustainable hotel management and effectively engage high-potential market segments. Full article

The spread of non-indigenous species (NIS) in the Mediterranean poses complex challenges for coastal fisheries, yet the perceptions and adaptive responses of small-scale fishers remain poorly understood. This study surveyed 70 professional fishers across Greek insular and mainland ports to assess fishers’ local ecological knowledge, awareness, and operational strategies related to eleven established marine NIS. Semi-structured interviews recorded demographic and effort profiles, recognition rates, perceived environmental and economic impacts, catch frequencies, gear damage, injury incidents, and behavioral changes. Fishers in the study area demonstrated high overall awareness (~95%), but variable recognition of less familiar taxa (e.g., bigfin reef squid, squirrelfish). Venomous and gear-damaging species (pufferfish, lionfish, rabbitfish) were predominantly viewed negatively, with significant reported gear losses (EUR 600–1345 yr⁻¹) and avoidance of high-incidence areas (25–30% of respondents). Conversely, commercially valuable NIS received more positive appraisals and are increasingly targeted. Spatial heterogeneity in perceptions and adaptations underscores the need for regionally tailored management that integrates fishers’ knowledge, promotes safe handling and selective exploitation of marketable NIS, and supports adaptive governance to mitigate ecological risks while enhancing socioeconomic resilience. Full article

Controlling air pollution from sea-going vessels is crucial to the sustainable development of maritime transportation. However, emissions of intermediate volatility organic compounds (IVOCs), an emerging aerosol precursor, remain poorly understood. This study developed a ship-type-, fuel-, and operating-mode-specific IVOC emission factor dataset based on existing real-world vessel measurements, and a ship-call-based IVOC inventory methodology tailored for regulatory applications. We quantified IVOC emissions from sea-going ships (excluding fishing and military vessels) entering or departing from the ports in the Economic Zone on the West Coast of the Taiwan Straits in 2014. The total IVOC emissions were 481.4 ± 220.0 t, with Xiamen Port contributing the highest share. Cargo and passenger ships accounted for 65% and 21% of emissions, respectively. While switching to low-sulfur and ultra-low-sulfur fuels increased IVOC emissions by 87% and 49% compared to high-sulfur fuels, the greater reductions in particulate matter and SO₂ emissions still yielded net environmental benefits. The ship IVOC emissions might have become more important in recent years due to enhanced port activity and fuel switching. Uncertainty analysis emphasizes the urgent need for IVOC emission testing on more vessel types. By providing a high-resolution profile of IVOC emissions from selected ports, this study underscores the urgency of adopting shore power and zero-emission vessels to mitigate organic aerosol pollution and offers a foundation for refining environmental impact assessments and efficient emission control policies to achieve sustainability in maritime transportation. Full article

Obtaining electricity from water wave energy using energy converters has a long history, but there are still relatively few commercial devices in the world compared to other solutions using renewable energy. The probable reasons for this state of affairs are operating costs, the cost of minimizing navigation risk for ships, and the geographical and hydro-meteorological specificity of various sea areas, resulting in the use of different, difficult-to-unify solutions. It can be concluded based on a literature analysis that there are no similar commercial solutions in Poland. This article presents the characteristics of waves in the South Baltic Sea near the Polish coast. Calculations of the output power were carried out for a selected type of wave energy converter (point absorber—PA) with different design parameters stimulated by wave energy with variable amplitude and period. These calculations for three characteristic cases are related to a feasibility study of the placement of power point absorbers in the water area around the port of Łeba in Poland. Finally, a short analysis of the results is presented. The obtained calculation results under Polish EEZ conditions are promising because we obtained above 304 KW of energy for 17% of the wave time per year, which seems to be good for local applications. Full article

This literature review examines the relationship between the number and type of deficiencies identified during Port State Control (PSC) inspections and a ship’s overall risk. The main objective is to synthesise the current academic evidence, detailing the analytical methodologies employed and highlighting key research contributions. The selection of literature has focused on peer-reviewed articles and relevant doctoral theses addressing detention risk prediction, accident risk and ship risk profiling. The findings indicate a consistent correlation between PSC deficiencies and ship risk, although the nature and strength of this correlation may vary depending on the type of risk considered and the specific deficiencies. A methodological evolution is observed in the field, from descriptive statistical analyses and regressions towards more complex predictive models, such as Machine Learning (ML) and Bayesian Networks (BNs). This transition reflects a search for greater accuracy in risk assessment, going beyond simple numerical correlation to improve the selection of ships for inspection. Multivariate statistical techniques, on the other hand, focus on the identification of risk patterns and the evaluation of the PSC system. The conclusions underline the importance of deficiencies as indicators of risk, the need for differentiated inspection approaches and the persistent challenges related to data quality and model interpretability. Full article

The evolution of robotic surgery in urologic oncology has led to the emergence of single-port (SP) robotic systems as a potential alternative to the widely adopted multi-port (MP) platforms. This narrative review provides a comprehensive comparison between SP and MP robotic systems, the former of which received FDA approval in 2018 and CE marking in 2024, focusing on their application across radical prostatectomy, partial and radical nephrectomy, and radical cystectomy. Drawing from the most current literature, we examine perioperative outcomes, oncologic efficacy, postoperative recovery, and complication rates. The review highlights the technical challenges unique to SP surgery, including restricted triangulation, limited instrumentation, and a defined learning curve, while also emphasizing innovations such as transvesical prostatectomy and the Supine Anterior Retroperitoneal Access (SARA) approach. Additionally, we explore the potential impact of emerging technologies—such as artificial intelligence, augmented reality, and telesurgery—on the future of SP platforms. Despite early limitations, SP systems have demonstrated comparable safety and effectiveness in selected cases and may offer unique advantages in specific anatomical scenarios. Continued innovation, structured training, and robust long-term outcome data will be essential for the broader adoption and integration of SP robotic surgery in clinical practice. Full article

Background: Histone deacetylase 6 (HDAC6) is a unique class IIb HDAC isozyme characterized by two catalytic domains and a zinc finger ubiquitin-binding domain. It plays critical roles in various cellular processes, including protein degradation, autophagy, immune regulation, and cytoskeletal dynamics. Due to its multifunctional nature and overexpression in several cancer types, HDAC6 has emerged as a promising therapeutic target. Methods: In this study, we employed a ligand-based pharmacophore modeling approach using a structurally diverse set of known HDAC6 inhibitors. This was followed by the virtual screening of over 140,000 commercially available compounds from both the MolPort and Asinex databases. The screening workflow incorporated pharmacophore filtering, molecular docking, and molecular dynamic (MD) simulations. Binding free energies were estimated using Molecular Mechanics Generalized Born Surface Area (MM-GBSA) analysis to prioritize top candidates. A fluorometric enzymatic assay was used to measure HDAC6 activity, while cell viability assay by Cell Titer Glo was used to assess the anti-tumor activity against drug-sensitive and -resistant multiple myeloma (MM) cells. Western blotting was used to evaluate the acetylation of tubulin or histone H4 after treatment with selected compounds. Results: Three promising compounds were identified based on stable binding conformations and favorable interactions within the HDAC6 catalytic pocket. Among them, Molecular Mechanics Generalized Born Surface Area (MM-GBSA) analysis identified Compound 10 (AKOS030273637) as the top theoretical binder, with a ΔG_bind value of −45.41 kcal/mol. In vitro enzymatic assays confirmed its binding to the HDAC6 catalytic domain and inhibitory activity. Functional studies on MM cell lines, including drug-resistant variants, showed that Compound 10 reduced cell viability. Increased acetylation of α-tubulin, a substrate of HDAC6, likely suggested on-target mechanism of action. Conclusions: Compound 10, featuring a benzyl 4-[4-(hydroxyamino)-4-oxobutylidene] piperidine-1-carboxylate scaffold, demonstrates potential drug-like properties and a predicted bidentate zinc ion coordination, supporting its potential as an HDAC6 inhibitor for further development in hematologic malignancies. Full article

Reliable, timely and economical target organism detection in harbors and ballast water is urgently needed to prevent the spread of aquatic invasive species (AIS) by commercial ships in the North American Great Lakes (NAGL). Inter-Great Lake ships (Lakers) transport large volumes (ca. 52 million metric tons. annually) of untreated lake water between lakes, with over 50% transported against the natural flow from the lower lakes to Western Lake Superior ports. The transport of ballast water is the number one threat of AIS spread throughout the NAGL. A relatively new tool to fight the spread of AIS is the use of eDNA for rapid detection and identification of target organisms. This technology opens doors for advancing control of ballast-mediated AIS through rapid detection. To that end, we have developed species-specific, reliable eDNA primers to target specific detection of four AIS in water samples along with qPCR protocols. Target organisms were selected based on the following criteria: (1) they are known to be invasive in the lower NAGL, (2) they are established in the lower NAGL but not in Superior, (3) they are biodegradable, and (4) they are obtainable, morphologically distinct and have existing DNA sequence information. Working primers, qPCR protocols and detection limits are provided for three invertebrate species and one alga species. These species are Daphnia lumholtzi (a water flea), Cercopagis pengoi (the fishhook water flea), Echinogammarus ishnus (a scud) and Nitellopsis obtusa (Starry Stonewort). Full article

This paper presents a method of compensating the AC pulsation appearing in the DC-link of a four-wire AC/DC converter operating with asymmetric output currents. If such a converter is operating with an electrochemical energy storage system, the AC component can cause several issues for the battery. In order to solve this problem, a DC/DC converter is used to redirect the AC component into a capacitor bank. The triple-active bridge (TAB) converter is selected for this purpose. The converter is modeled using a reduced-order modelling approach, and the appropriate control loop is designed. The experimental setup is built and tested with a modelled DC-link, with emulated pulsation. The average AC component reduction on the battery port of 98.3% is achieved. Full article

Recent advancements in composite materials design have made glass fiber-reinforced polymer composites (GFRPC) a viable choice for a wide range of engineering and industrial applications. Although GFRPCs boast attractive characteristics such as low specific mass and high specific mechanical strength, identifying and characterizing damage mechanisms in these materials is challenging. Several scientific studies have examined the root causes of GFRPC failure using various methods, including non-destructive techniques and learning algorithms. Despite this, ongoing investigations aim to accurately detect mechanical defects in GFRPCs. This study explores the use of non-destructive testing (NDT) combined with unsupervised learning algorithms to identify and classify damage mechanisms in GFRPCs. The NDT method employed in this study is acoustic emission (AE), which identifies waveforms associated with various failure mechanisms during testing. These waveforms are categorized using unsupervised learning methods such as principal component analysis (PCA) and self-organizing maps. PCA selects the most appropriate AE descriptors for distinguishing between different damage mechanisms, while the self-organizing maps algorithm performs clustering analysis and classifies failure mechanisms. Scanning electron microscope images of the observed failures are provided to sup-port the findings derived from AE data. Full article

This paper addresses the critical challenge of selecting suitable pile foundations in port engineering by systematically investigating the axial bearing behavior of large-diameter steel pipe piles and prestressed high-strength concrete (PHC) piles. The study integrates both numerical simulations and field tests within the context of the Yancheng Dafeng Port Security Facilities Project. A self-balanced static load numerical model for PHC piles was developed using Plaxis 3D, enabling the simulation of load-displacement responses, axial force transfer, and side resistance distribution. The accuracy of the model was verified through a comparison with field static load test data. With the verified model parameters, the internal force distribution of steel pipe piles was analysed by modifying material properties and adjusting boundary conditions. A comparative analysis of the two pile types was conducted under identical working conditions. The results reveal that the ultimate bearing capacities of the 1# steel pipe pile and the 2# PHC pile are 6734 kN and 6788 kN, respectively. Despite the PHC pile having a 20% larger diameter, its ultimate bearing capacity is comparable to that of the steel pipe pile, suggesting a more efficient utilisation of material strength in the latter. Further numerical simulations indicate that, under the same working conditions, the ultimate bearing capacity of the steel pipe pile exceeds that of the PHC pile by 18.43%. Additionally, the axial force distribution along the steel pipe pile shaft is more uniform, and side resistance is mobilised more effectively. The reduction in side resistance caused by construction disturbances, combined with the slenderness ratio (L/D = 41.7) of the PHC pile, results in 33.87% of the pile’s total bearing capacity being attributed to tip resistance. The findings of this study provide crucial insights into the selection of optimal pile types for terminal foundations, considering factors such as bearing capacity, environmental conditions, and economic viability. Full article