bluuebunny/crossref_metadata_2025 huggingface dataset:
Becoming Self Employed: Israeli Family Physicians’ Push and Pull Factors
Authors: Chudner Irit , Shnider Avi , Gluzman Omer , Keidar Hadas , Haimi Motti
Published: September 2024

Background: As primary care is an important infrastructure for the entire health system, the employment structure choices of family physicians—whether to work in a managed care organization or be self-employed, can impact all effectiveness parameters of healthcare: quality, access, health equity, patients’ experiences, and cost-effectiveness. The aim of this study is to assess the push and pull factors influencing family physicians’ employment choices. Methods: This study employed a qualitative approach to explore the experiences of family physicians (FPs) who choose to work a self-employment practice. We conducted semi-structured interviews with twenty-seven self-employed FPs in Israel, selected through purposive and snowball sampling. The interviews were conducted via Zoom, recorded, and transcribed verbatim. Data analysis followed thematic analysis framework. The analysis yielded 10 themes, which were organized into two categories: pull and push factors. Results: Pull factors, i.e., factors that attract family physicians to become self-employed, included professional self-fulfillment, higher income, professional and business autonomy, working with secretaries according to one’s personal choice, designing the space of the clinic, and flexibility in working hours. Push factors, i.e., factors that demotivated family physicians to work under managed care and pushed them to choose self-employment included low control over the work environment, workload, decreased professional and organizational autonomy, managerial pressures on quality measures, engagement in marketing activities, and tensions with non-medical staff in the Health Maintenance Organization. Conclusions: There are obvious implications of this work for Health Maintenance Organizations’ policy makers. Balancing managerial pressure and tensions between family physicians and non-medical administration and ensuring suitable working conditions increased physicians’ control over the work environment, and professional autonomy may decrease push factors and retain family physicians as Health Maintenance Organization-employed. Understanding pull factors may help to develop a strategy for maximizing cooperation with self-employed family physicians and reinforce physicians’ linkage to the healthcare system’s treatment objectives.
Long-Term Impact of Community Psychiatric Care on Quality of Life amongst People Living with Schizophrenia: A Systematic Review
Authors: Černe Kolarič Jožica , Plemenitaš Ilješ Anja , Kraner Darja , Gönc Vida , Lorber Mateja , Mlinar Reljić Nataša , Fekonja Zvonka , Kmetec Sergej
Published: September 2024

The review examines the long-term impact of community psychiatric care on improving the quality of life of people with schizophrenia. It addresses the global burden of this disorder and the need for effective community-based care strategies. A systematic literature search was conducted in databases such as CINAHL, Medline, Web of Science, Sage and ScienceDirect, with the search lasting until March 2024 and following the PRISMA guidelines. The inclusion criteria targeted studies that addressed the long-term effects of community mental health care for people aged 18 years and older with schizophrenia and included both quantitative and qualitative research designs. Studies unrelated to the research question or with significant methodological flaws were excluded. The risk of bias was assessed using GRADE and GRADECERqual, in addition to critical appraisal using the Joanna Briggs Institute (JBI) checklists. Independent screening and data extraction was performed, with results summarised by thematic analysis. In total, 11 studies met the inclusion criteria and included cross-sectional, cohort, qualitative and randomised controlled trial designs. The results showed that community psychiatric care significantly improves the quality of life, well-being and social integration of people with schizophrenia. Effective interventions identified include psychoeducation, cognitive behavioural therapy, social skills training and individualised care plans. However, challenges such as limited resources, labour shortages and social stigma, particularly in low-income neighbourhoods, were also identified. This study highlights the importance of continuous, personalised, multidisciplinary community-based care for sustainable mental health outcomes. Further research is recommended to investigate the long-term impact and strategies to overcome implementation challenges.
Livelihood Vulnerability from Drought among Smallholder Livestock Farmers in South Africa
Authors: Bahta Yonas T. , Nyaki Stephen Aniseth
Published: September 2024

The impacts of drought and climate change on agriculture have become increasingly apparent, and affect smallholder livestock farmers. Farmers’ livelihoods rely on agriculture; thus, they are vulnerable to the primary and secondary impacts of climate change. In South Africa, policies for increasing the resilience of smallholder livestock farmers who have suffered from agricultural drought have not paid sufficient attention to the level of livelihood vulnerability. This study assessed the level of livelihood vulnerability of smallholder livestock farmers in the drought-stricken Frances Baard District Municipality in the Northern Cape Province of South Africa. The livelihood vulnerability of 217 randomly selected farmers from the municipality were determined using the Livelihood Vulnerability Index (LVI) and Livelihood Vulnerability Index of the Intergovernmental Panel on Climate Change (LVI-IPCC), which includes seven components and 34 subcomponents addressing livelihood. A high level of livelihood vulnerability, with an LVI score of 0.436, was determined and attributed to high-risk livelihood strategies, food, social networks, health, water, sociodemographics, natural disasters, and climate change. The LVI-IPCC of 0.04 also showed moderate vulnerability due to high exposure, high sensitivity, and low adaptive capacity, especially for the Phokwane, Dikgatlong, and Magareng districts in the Frances Baard municipality. Given continued drought recurrences, it is crucial for the government and other stakeholders to implement strategic and targeted sustainable interventions. The resilience of smallholder livestock farmers should be enhanced by increasing their adaptive capacity through diversified livelihood options while decreasing exposure and sensitivity to agricultural drought risks.
The Wheel–Rail Contact Force for a Heavy-Load Train Can Be Measured Using a Collaborative Calibration Algorithm
Authors: Wen Tianning , He Jing , Zhang Changfan , He Jia
Published: September 2024

The wheel–rail contact force is a crucial indicator for ensuring the secure operation of a heavy-load train. However, obtaining the real-time wheel–rail contact force of a heavy-load train is a challenging task as, due to safety considerations, it is not possible to install instrumented wheelsets on heavy-load trains. This work presents a novel approach to quantify the wheel–rail contact force of a heavy-load train, utilizing a cooperative calibration methodology. First, a ground measurement platform for the wheel–rail contact force of a heavy-load train is constructed on a selected rail section. The railway inspection car’s wheel–rail contact force measurement system is fine-tuned using a multilayer perceptron calibration approach, and the ground platform then uses the results to fine-tune the railway inspection car’s examined wheelset. Second, based on actual measured data on the wheel–rail contact force of a heavy-load train, and using the golden jackal optimization algorithm, the multilayer perceptron correction approach is employed to create a data relationship mapping model. This model correlates the corrected data on the wheel–rail contact force obtained from the railway inspection car with the wheel–rail contact force of a heavy-haul train with an axle load of 25 tons, and the precision of the mapping is guaranteed. Finally, by combining the wheel–rail contact force correction method for the railway inspection car and the contact force mapping model between the railway inspection car and the heavy-load train, collaborative calibration of the wheel–rail contact force of the heavy-load train is realized. The experimental results under two working conditions show that this method can realize high-precision, real-time measurement of the wheel–rail contact force of a heavy-load train. For the working condition of a straight-line section, the calibration error was within 1.593 kN, and the MAPE was 0.105%; for the working condition of a curved-line section, the calibration error was 2.344 kN, and the RMSE was 184.72 N.
Growth, Spectroscopic Characterization and Continuous-Wave Laser Operation of Er,Yb:GdMgB5O10Crystal
Authors: Gorbachenya Konstantin N. , Volkova Elena A. , Maltsev Victor V. , Kisel Victor E. , Mitina Diana D. , Koporulina Elizaveta V. , Kuzmin Nikolai N. , Marchenko Ekaterina I. , Kosorukov Vladimir L.
Published: September 2024

A transparent Er3+,Yb3+:GdMgB5O10 single crystal with dimensions up to 24 × 15 × 12 mm was grown successfully by the high-temperature solution growth on dipped seeds technique from K2Mo3O10-based solvent. The grown crystal was characterized using PXRD, DSC and ATR techniques. Differential scanning calorimetry measurements and SEM analysis of the heat-treated solids revealed Er,Yb:GdMgB5O10 to be an incongruent melting compound with an onset point of 1087 °C. The absorption edge of the Er,Yb:GMBO sample is located in the region of 245 nm, which approximates a value of 4.8 eV. Absorption and emission spectra, and luminescence kinetics, were studied. The energy transfer efficiency from ytterbium to erbium ions was determined. The laser operation in continuous-wave mode was realized and output characteristics were measured. The maximal output power of 0.15 W with a slope efficiency of 11% was obtained at 1568 nm.
Mortality Predictors and Neurological Outcomes Following Extracorporeal Cardiopulmonary Resuscitation (eCPR): A Single-Center Retrospective Study
Authors: Rajsic Sasa , Tauber Helmuth , Breitkopf Robert , Velik Salchner Corinna , Mayer Fabian , Oezpeker Ulvi Cenk , Treml Benedikt
Published: September 2024

Background: Extracorporeal cardiopulmonary resuscitation (eCPR) offers cardiorespiratory support to patients experiencing cardiac arrest. However, this technology is not yet considered a standard treatment, and the evidence on eCPR criteria and its association with survival and good neurological outcomes remains scarce. Therefore, we aimed to investigate the overall mortality and risk factors for mortality. Moreover, we provide a comparison of demographic, clinical, and laboratory characteristics of patients, including neurological outcomes and adverse events during support. Methods: This retrospective analysis included in-hospital and out-of-hospital cardiac arrest patients who received eCPR and were admitted between January 2008 and June 2022 at a tertiary and trauma one-level university hospital in Austria. Results: In total, 90 patients fulfilled inclusion criteria, 41 (46%) patients survived until intensive care unit discharge, and 39 (43%) survived until hospital discharge. The most common cause of cardiac arrest was myocardial infarction (42, 47%), and non-shockable initial rhythm was reported in 50 patients (56%). Of 33 survivors with documented outcomes, 30 had a good recovery as measured with Cerebral Performance Category score, 2 suffered severe disability, and 1 remained in a persistent vegetative state. Finally, multivariate analysis identified asystole as initial rhythm (HR 2.88, p = 0.049), prolonged CPR (HR 1.02, p = 0.043), and CPR on the weekend (HR 2.57, p = 0.032) as factors with a higher risk of mortality. Conclusions: eCPR-related decision-making could be additionally supported by the comprehension of the reported risk factors for mortality and severe disability. Further studies are needed to elucidate the impact of peri-arrest variables on outcomes, aiming to improve patient selection.
Focus on the Role of Non-Invasive Respiratory Support (NRS) during Palliative Care in Patients with Life-Limiting Respiratory Disease
Authors: Spinazzola Giorgia , Ferrone Giuliano , Michi Teresa , Torrini Flavia , Postorino Stefania , Sbaraglia Fabio , Gulmini Loretta , Antonelli Massimo , Conti Giorgio , Spadaro Savino
Published: September 2024

The management of patients with life-threatening respiratory disease in the ICU and at home has become increasingly of interest over the past decades. Growing knowledge supports the use of NRS, aimed at improving patient comfort and improving quality of life. However, its role during palliative care is not well defined, and evidence of support remains limited. The aim of this narrative review is to examine the recent evidence relating to the use of non-invasive respiratory support at the end of life, in order to clarify who benefits and when. The literature research was conducted on PubMed, using MeSH words. A review of the relevant literature showed that non-invasive respiratory support techniques for patients with life-limiting respiratory disease vary (from high-flow oxygen therapy to conventional oxygen therapy, from CPAP to NPPV) and each has precise indications. To date, from the hospital to the home setting, the monitoring and application of these respiratory support techniques have varied widely. In conclusion, the choice of respiratory support in this category of patients should be based on the technique that will optimize the comfort of the patient and improve the quality of their life. On the other hand, regarding monitoring, both telemedicine and ultrasound diagnostics help to satisfy the patient’s wish to spend the last period of his life in the home environment, to avoid inappropriately aggressive diagnostic interventions, and to reduce the high costs of hospitalized procedures in this category of patients.
The Impact of Standing Electric Scooters on Maxillofacial Fractures: An Italian Multi-Centric Epidemiological Study
Authors: Salzano Giovanni , Maffia Francesco , Vaira Luigi Angelo , Fusco Roberta , Albanese Massimo , Crimi Salvatore , Cucurullo Marco , Maglitto Fabio , Maugeri Claudia , Petrocelli Marzia , Pitino Francesca , Priore Paolo , Roccia Fabio , Tel Alessandro , Baietti Anna Maria , Bianchi Alberto , Biglioli Federico , Copelli Chiara , De Riu Giacomo , Nocini Pier Francesco , Ramieri Guglielmo , Robiony Massimo , Valentini Valentino , Califano Luigi
Published: September 2024

Objectives: This study aimed to determine the impact of standing electric scooters on maxillofacial on the Italian territory. Methods: The authors analyzed the epidemiology of the injuries to define electric mobility’s impact on maxillofacial surgery practice. For this retrospective cohort study, data were collected by unifying the standing e-scooter-related fractures database from 10 Italian maxillofacial surgery departments. The reference period considered was from January 2020 to December 2023. The main data considered included age, gender, type of access, time slot of admission, type of admission, alcohol level, helmet use, dynamics of the accident, and area of the fracture. Results: A total of 79 patients were enrolled. The average age of the participants was approximately 31 years. The blood alcohol level was found to be above the Italian norm in 15 cases (19%). Only one patient wore a helmet. The most affected facial third was the middle one with 36 cases (45.5%), followed by the lower one (31, 39.3%). The most recurrent patterns were fractures of the orbito-malar-zygomatic complex (15, 19%), followed by multifocal (bifocal, trifocal) fractures of the mandible (14, 17.5%). Conclusions: This study demonstrated how maxillofacial fractures related to the use of electric scooters are associated with complex patterns, associated with a high rate of post-surgical aftermaths.
Inflammation and Vasculitis Related to Brolucizumab
Authors: Campos António , Mota Carolina , Caramelo Francisco , Oliveira Nuno , Silva Sara , Sousa João
Published: September 2024

Background/objectives: To compare the prevalence of intra-ocular inflammation (IOI) between brolucizumab and aflibercept in neovascular age-related macular degeneration (nAMD) after intra-vitreal injections (IVI) and to compare the IOI odds ratios (ORs) of both therapies with the prevalence of septic endophthalmitis after IVI that was previously reported in the literature. Methods: A total of 468 IVI of brolucizumab (117 eyes) were compared with 2884 IVI of aflibercept (305 eyes) regarding IOI and occlusive retinal vasculitis (RV) from December 2021 to June 2023 in this retrospective study. The OR was calculated for both anti-VEGF agents and was compared with the relative risk of septic endophthalmitis after IVI. Results: There were four eyes with unilateral IOI related to brolucizumab (3.42%), one presenting uveitis (0.85%), two vitritis (1.71%) and the last one presenting occlusive RV (0.85%), compared with two eyes presenting unilateral IOI (anterior uveitis, 0.66%) and none with RV from the aflibercept cohort. The incidence of IOI per injection with brolucizumab (0.855%) was significantly higher compared with aflibercept (0.069%, p = 0.004). The OR of IOI related to brolucizumab IVI compared with septic endophthalmitis was 20 times greater (1.49 for aflibercept, p = 0.646, versus 20.15 for brolucizumab, p < 0.001). The OR of RV with brolucizumab compared with septic endophthalmitis was 4.6. Conclusion: Data from our department suggest a much higher risk of IOI and occlusive retinal vasculitis after brolucizumab when compared with aflibercept. The risk of IOI and severe sight-threatening complications related to brolucizumab is greater than the risk of septic endophthalmitis after any IVI.
Evidence on Hidradenitis Suppurativa as an Autoinflammatory Skin Disease
Authors: D’Onghia Martina , Malvaso Dalma , Galluccio Giulia , Antonelli Flaminia , Coscarella Giulia , Rubegni Pietro , Peris Ketty , Calabrese Laura
Published: September 2024

Hidradenitis suppurativa (HS) is a chronic and debilitating inflammatory skin disease that often exhibits heterogeneity in its clinical presentation, especially in the context of its rare syndromic forms. The pathogenesis of HS results from a complex interplay of genetic predisposition, innate and adaptive immunity dysregulation, smoking, obesity and environmental factors. In the early phase of the disease, the innate immune system is hyperactivated, contributing to tissue damage and triggering the activation and amplification of the adaptive immune response, which plays a pivotal role in the chronic stages of the disease. Recent studies focused on elucidating the importance of innate immunity impairment and autoinflammation in HS and increasing evidence has emerged on the occurrence of the disease in the context of well-known monogenic and polygenic autoinflammatory syndromes (AIDs). This review provides a comprehensive examination of the current scientific background supporting the contribution of autoinflammation to HS etiology, including genetic data, molecular studies and clinical evidence, as well as the association between HS and AIDs. However, further research is needed to shed light on the pathogenic mechanism of this challenging condition and to identify potential perspectives for future therapeutic approaches.
Bioengineering Approaches and Novel Biomaterials to Enhance Sternal Wound Healing after Cardiac Surgery: A Crosstalk between Innovation and Surgical Practice
Authors: Ferrisi Chiara , Loreni Francesco , Nenna Antonio , Giacinto Omar , Lusini Mario , Chello Massimo
Published: September 2024

Median sternotomy and steel wires for sternal closure are the standard approach for cardiac surgery. An incomplete repair associated with chest wall motion, especially in the presence of predisposing factors, can lead to life-threatening deep sternal wound infection, also known as mediastinitis, in 2–5% of cases. Despite current antibiotic and surgical treatments, mediastinitis is associated with a 10–40% mortality rate and a significant increase in morbidity and hospital stay. High mortality and difficult treatment appear to be due to bacterial biofilm, a self-produced extracellular polymeric product that incorporates host tissue and is responsible for the failure of immune defenses and standard antimicrobial therapies. Nanostructures are an effective strategy to enhance the healing process, as they establish a favorable environment for the neosynthesis of the extracellular matrix, supporting tissue development. Synthetic polymers have been proven to exhibit suitable biodegradable and mechanical properties, and their biofunctionalization to enhance cell attachment and interaction with the extracellular matrix is being widely investigated. The use of antibiotic treatments suspended in poly-D,L-lactide and polyethylene oxide and electrospun into nanofibers, or in sponges, has been shown to inhibit bacterial biofilm production. Additionally, growth factors can be incorporated into 3D bioresorbable scaffolds with the aim of constituting a structural and biological framework to organize and expedite the healing process. Therefore, these combined approaches may change the treatment of mediastinitis in the near future.
Concurrent Validity and Reliability of a Free Smartphone Application for Evaluation of Jump Height
Authors: Dias Amândio , Pires Paulo , Santana Leandro , Marques Paulo , Espada Mário C. , Santos Fernando , Silva Eduardo Jorge Da , Rebelo André , Teixeira Diogo S.
Published: September 2024

Background/Objectives: Jump test assessment is commonly used for physical tests, with different type of devices used for its evaluation. The purpose of the present study was to examine the validity and reliability of a freely accessible mobile application (VertVision, version 2.0.5) for measuring jump performance. Methods: With that intent, thirty-eight college age recreationally active subjects underwent test assessment after a specific warm-up, performing countermovement jumps (CMJs) and squat jumps (SJs) on a contact platform while being recorded with a smartphone camera. Jump height was the criterion variable, with the same formula being used for both methods. Data analysis was performed by two experienced observers. Results: The results showed strong correlations with the contact platform (ICC > 0.9) for both jumps. Furthermore, between-observer reliability was also high (ICC > 0.9; CV ≤ 2.19), with lower values for smallest worthwhile change (≤0.23) and typical error of measurement (≤0.14). Estimation error varied when accounting for both observers, with the SJ accounting for bigger differences (4.1–6.03%), when compared to the CMJ (0.73–3.09%). Conclusions: The study suggests that VertVision is a suitable and handy method for evaluating jump performance. However, it presents a slight estimation error when compared to the contact platform.
Editorial for the Special Issue on “Feature Papers in Section AI in Imaging”
Authors: Fernández-Caballero Antonio
Published: September 2024

Artificial intelligence (AI) techniques are being used by the imaging academia and industry to solve a wide range of previously intractable problems [...]
Concrete Crack Detection and Segregation: A Feature Fusion, Crack Isolation, and Explainable AI-Based Approach
Authors: Swarna Reshma Ahmed , Hossain Muhammad Minoar , Khatun Mst. Rokeya , Rahman Mohammad Motiur , Munir Arslan
Published: September 2024

Scientific knowledge of image-based crack detection methods is limited in understanding their performance across diverse crack sizes, types, and environmental conditions. Builders and engineers often face difficulties with image resolution, detecting fine cracks, and differentiating between structural and non-structural issues. Enhanced algorithms and analysis techniques are needed for more accurate assessments. Hence, this research aims to generate an intelligent scheme that can recognize the presence of cracks and visualize the percentage of cracks from an image along with an explanation. The proposed method fuses features from concrete surface images through a ResNet-50 convolutional neural network (CNN) and curvelet transform handcrafted (HC) method, optimized by linear discriminant analysis (LDA), and the eXtreme gradient boosting (XGB) classifier then uses these features to recognize cracks. This study evaluates several CNN models, including VGG-16, VGG-19, Inception-V3, and ResNet-50, and various HC techniques, such as wavelet transform, counterlet transform, and curvelet transform for feature extraction. Principal component analysis (PCA) and LDA are assessed for feature optimization. For classification, XGB, random forest (RF), adaptive boosting (AdaBoost), and category boosting (CatBoost) are tested. To isolate and quantify the crack region, this research combines image thresholding, morphological operations, and contour detection with the convex hulls method and forms a novel algorithm. Two explainable AI (XAI) tools, local interpretable model-agnostic explanations (LIMEs) and gradient-weighted class activation mapping++ (Grad-CAM++) are integrated with the proposed method to enhance result clarity. This research introduces a novel feature fusion approach that enhances crack detection accuracy and interpretability. The method demonstrates superior performance by achieving 99.93% and 99.69% accuracy on two existing datasets, outperforming state-of-the-art methods. Additionally, the development of an algorithm for isolating and quantifying crack regions represents a significant advancement in image processing for structural analysis. The proposed approach provides a robust and reliable tool for real-time crack detection and assessment in concrete structures, facilitating timely maintenance and improving structural safety. By offering detailed explanations of the model’s decisions, the research addresses the critical need for transparency in AI applications, thus increasing trust and adoption in engineering practice.
FineTea: A Novel Fine-Grained Action Recognition Video Dataset for Tea Ceremony Actions
Authors: Ouyang Changwei , Yi Yun , Wang Hanli , Zhou Jin , Tian Tao
Published: September 2024

Methods based on deep learning have achieved great success in the field of video action recognition. When these methods are applied to real-world scenarios that require fine-grained analysis of actions, such as being tested on a tea ceremony, limitations may arise. To promote the development of fine-grained action recognition, a fine-grained video action dataset is constructed by collecting videos of tea ceremony actions. This dataset includes 2745 video clips. By using a hierarchical fine-grained action classification approach, these clips are divided into 9 basic action classes and 31 fine-grained action subclasses. To better establish a fine-grained temporal model for tea ceremony actions, a method named TSM-ConvNeXt is proposed that integrates a TSM into the high-performance convolutional neural network ConvNeXt. Compared to a baseline method using ResNet50, the experimental performance of TSM-ConvNeXt is improved by 7.31%. Furthermore, compared with the state-of-the-art methods for action recognition on the FineTea and Diving48 datasets, the proposed approach achieves the best experimental results. The FineTea dataset is publicly available.
Determination of Chip Compression Ratio for the Orthogonal Cutting Process
Authors: Storchak Michael
Published: September 2024

The chip compression ratio is the most important characteristic of various machining processes with chip generation. This characteristic enables the determination of kinetic and other energy loads on the tool and the machined material. This provides an overall evaluation of the machining process and the possibility of its subsequent optimization. This paper presents the results of determining this cutting characteristic by experimental method, analytical calculation, and numerical modeling. For the analytical calculation of the chip compression ratio, an analytical cutting model developed based on the variational principle of the minimum potential energy was used. A finite element model of orthogonal cutting was used for the numerical simulation of the above process characteristic. Experimentally, the chip compression ratio was determined by the ratio of the chip thickness to the cutting depth (undeformed cutting thickness). The chip thickness was determined by direct measurement using chip slices obtained during the cutting process. The Johnson–Cook constitutive equation was used as the machined material model and the Coulomb model was used as the friction model. The generalized parameters’ determination of the constitutive equation was performed through a DOE (Design of Experiment) sensitivity analysis. The variation range of these parameters was chosen based on the analysis of the effect of individual parameters of the constitutive equation on the chip compression ratio value. The largest deviations between the experimental and analytically calculated values of the chip compression ratio did not exceed 21%. At the same time, the largest deviations of simulated values of the indicated cutting characteristic and its experimental values did not exceed 20%. When comparing the experimental values of the chip compression ratio with the corresponding calculated and simulated values, the deviations were within 22%.
Provenance Analysis of the Northern Offshore Mud Area of the Shandong Peninsula, China, Spanning the Last 2000 Years
Authors: Wu Shuyu , Liu Jun , Feng Yongcai
Published: September 2024

The mud area in the northern offshore of the Shandong Peninsula constitutes a dynamic source–sink system in China’s continental shelf and is a hotspot for research. However, the provenance of the sediments remains controversial, and the depositional environment is not yet fully understood. This paper performed accelerator mass spectrometry 14C dating, grain-size analysis, clay mineralogic analysis, and geochemical analysis of the ZZ04 sediment core. The results showed that this core primarily comprises silt and clay, reflecting weak sedimentary hydrodynamic conditions and stable deposition. The clay mineral assemblage—illite, smectite, chlorite, and kaolinite—indicates strong physical weathering. The provenance of the mud area was mainly from the Yellow River, Shandong Peninsula rivers, and Yangtze River, highlighting its multi-source characteristics. The smectite/(illite + chlorite) ratio in the ZZ04 core serves as a mineralogical indicator of the East Asian summer monsoon (EASM). Eight significant East Asian winter monsoon (EAWM) intensifications were identified, correlating with global cooling events similar to those at 1.89, 1.4, 1.03, and 0.62 thousand years ago. During the EAWM period, the coastal current and the Yellow Sea warm current play crucial roles in the transportation of matter and heat flux in the mud area. In contrast, during the EASM period, the sediments are predominantly sourced from the Shandong Peninsula rivers, contributing terrigenous materials shaped by chemical weathering.
Numerical Study of Discharge Coefficients for Side-Damaged Compartments
Authors: Tian Siwen , Peng Fei , Wang Zhanzhi , Li Jingda
Published: September 2024

Accurately evaluating the buoyancy and stability of damaged ships, particularly the flow rate of the water inflow through damaged openings, is of great significance for ship rescue and emergency repair. A three-dimensional simplified model of inflow for a ship’s damaged side bulkheads is established using the shear stress transport k-epsilon and volume of fluid (VOF) models by STAR-CCM+. Moreover, the flow rates of water inflow through damaged openings with different shapes, characteristic sizes, and central depths are calculated. Furthermore, the corresponding discharge coefficients are obtained, and the relevant rules are summarized. It was found that the influence of water depth on the coefficient is minimal in these work conditions, but from the perspective of the damaged opening’s characteristic dimensions and shape, the variation in the coefficient is more pronounced. Overall, the triangular opening has a higher coefficient than the circular opening, which in turn is higher than that of the square-damaged opening, and the coefficient decreases as the size of the opening increases. Lastly, empirical formulas for two different methods are provided. The research provides a reference for the rescue repair and buoyancy stability assessment of damaged ships.
An Analysis of the Importance of Success Factors for Cloud Computing System Adoption in Vessel Traffic Service Systems
Authors: Shin Gil-ho , Yoo Yunja , Song Chae-Uk
Published: September 2024

This study aims to identify the key success factors for the adoption of a cloud computing system in vessel traffic service (VTS) systems and evaluate the relative importance of each factor. Through a literature review and expert Delphi surveys, 12 success factors were derived across the dimensions of technology, organization, environment, and institution. The results of the analytic hierarchy process (AHP) analysis revealed that stability in the technological dimension was the most important factor. This study provides useful implications for future decision-making in VTS cloud adoption by systematically identifying the key success factors and presenting their priorities through the application of the TOE-I framework to VTS cloud computing.
The Effects of Controlling Gas Escape and Bottom Current Activity on the Evolution of Pockmarks in the Northwest of the Xisha Uplift, South China Sea
Authors: Li Xuelin , Guo Xudong , Tian Fei , Fang Xiaochen
Published: September 2024

Submarine pockmarks are typical indicators of submarine gas escape activity. The deep strata of the Xisha Uplift are rich in biogenic and thermogenic gas, accompanied by strong bottom current activity. Investigating the effects of controlling submarine gas escape and bottom current activity on the formation and development of pockmarks in the Xisha Uplift is significant for understanding the evolution of submarine topography and geomorphology. This study utilized high-resolution multibeam data to identify 261 submarine pockmarks in the northwest of the Xisha Uplift. These pockmarks were categorized based on their morphology into circular, elliptical, elongated, crescent-shaped, and irregular types. The diameters of pockmarks in the study area range from 0.21 to 4.96 km, with maximum depths reaching 30.88 m. Using high-resolution multi-channel seismic data, we conducted a detailed analysis of the subsurface strata characteristics of the pockmarks, identifying chaotic weak reflections, bright spots, and high-angle reflectors. We believe that deep gas in the northwest of the Xisha Uplift escapes to the seafloor through migration pathways, such as faults, fractures, and gas chimneys, resulting in the formation of submarine pockmarks. Bottom current activity has a significant impact on already-formed pockmarks. Crescent-shaped and elongated pockmarks in the Xisha Uplift are largely the result of bottom current modifications of pre-existing pockmarks.
Genetic Variability and Population Genetic Structure of Marbled Flounder Pseudopleuronectes yokohamae in Korea and Japan Inferred from mtDNA Control Region Sequences
Authors: Gwak Woo-Seok , Roy Animesh
Published: September 2024

The marbled flounder (Pseudopleuronectes yokohamae) is a demersal flatfish species, widely distributed in the northwestern Pacific region. In the present study, the mitochondrial DNA (mtDNA) control region was used to determine the genetic diversity and population genetic structure of this species. We obtained a 380 bp segment of the mtDNA control region after the alignment of 78 individual sequences from P. yokohamae collected from two locations in Korea (Biungdo and Mukho) and one location in Japan (Tohoku) and 103 individual sequences from a previous study (Yokjido and Namhae). The overall haplotype diversity and nucleotide diversity were 0.983 ± 0.003 and 0.016 ± 0.008, respectively. The genealogical relationships of the mtDNA control region did not exhibit any specific genealogical association according to sampling location. The pairwise FST value indicated that the Biungdo (west coast of Korea) and Tohoku (Japan) populations showed genetically differentiated structures (but the Tohoku and Mukho populations did not). However, there was no discernible difference between the Mukho population from Korea’s eastern coast and the Yokjido and Namhae populations from the southern coast. The biological characteristics of P. yokohamae and oceanographic barriers may have contributed to producing genetically distinct populations.
An Improved Artificial Electric Field Algorithm for Determining the Maximum Length of Gravel Packing in Deep-Water Horizontal Well
Authors: Yang Lei , Lin Hong , Zhou Shengtian , Feng Ziyue
Published: September 2024

Gravel packing in deep-water horizontal wells is an effective and practical sand control method, which is a key technical method to ensure efficient exploitation of deep-water oil and gas. To ensure the successful implementation of gravel packing in deep water horizontal wells, it is crucial to carry out effective optimization design of packing parameters. This paper proposes a novel optimization design approach for gravel packing in deep-water horizontal wells. In the proposed approach, an optimization model is proposed for gravel packing in deep-water horizontal wells, in which the gravel packing length is regarded as the objective function. Then, an improved artificial electric field algorithm (IAEFA) is introduced for optimizing the key gravel packing parameters so as to determine the maximum gravel packing length. For a specific case study, we conducted optimization calculations for gravel packing in a deep-water horizontal well. Results of the case study demonstrate that the optimization design approach based on the IAEFA algorithm can effectively address the parameter optimization problem of deep-water horizontal well gravel packing. For the target well of the case study, the maximum packing length obtained by the IAEFA algorithm could reach 1000.22 m, and the corresponding 3 sets of optimal packing parameters were also obtained. In the scenario of optimal packing parameters, the total time of gravel packing in target well is 566.6 min, and the total amount of sand consumption is 54,050.94 lbs. The bottom hole pressure during the injection stage remains stable with about 9780 psi, then slowly rises from 9788 psi to 9837 psi in the α-wave packing stage, and rapidly increases from 9837 psi to 9986 psi in the β-wave packing stage. The proposed approach provides an efficient and practical optimization tool for the optimal design of gravel packing in deep water horizontal wells.
The Spatiotemporal Pattern Evolution Characteristics of Ship Traffic on the Arctic Northeast Passage Based on AIS Data
Authors: Li Changrong , Li Zhenfu , Song Chunrui
Published: September 2024

Warming weather has led to melting sea ice, and increasingly complex global geopolitics has drawn more countries’ attention to the Arctic. The Arctic Northeast Passage, as an emerging route connecting Eurasia, has seen a sharp increase in vessel activity. The period from 2015 to 2020, being a stable and undisturbed data period, is of significant theoretical importance for exploring the natural development of the Arctic Northeast Passage. The study found that the research period can be divided into three stages: from 2015 to 2017, the number of vessels grew slowly. In 2018 and 2019, the number of vessels and vessel activities saw significant growth, but an unexpected reverse growth occurred in 2020. Different types of vessels have unique activity characteristics and evolutionary patterns, influenced by the Arctic’s unique geographical environment, abundant natural resources, deepening Sino-Russian cooperation, and increasing global trade supply and demand. The results of this study aim to provide policymakers with analysis based on the initial development stage of the route, offering data support for future policy formulation, route planning, and research on the navigation safety of vessels on the Arctic Northeast Passage.
Wave-Current Interaction Effects on the OC4 DeepCwind Semi-Submersible Floating Offshore Wind Turbine
Authors: Mazarakos Thomas P. , Mavrakos Spyridon A.
Published: September 2024

In order to investigate the hydrodynamic performances of semi-submersible type floating offshore wind turbines (FOWTs), particularly the effect of body-wave-current interaction, the OC4 FOWT is considered in the presence of co-existing regular wave and uniform current fields. The wind loads are not considered at this stage. The problem is treated in the framework of potential-flow theory in the frequency domain, assuming waves of small steepness, and the solution is obtained by using a perturbation expansion method for the diffraction potential with respect to the normalized current speed. Analytical and numerical formulations have been used to treat the inhomogeneous free-surface boundary condition involved in the hydrodynamic problem formulation for the derivation of the associated perturbation potential. The hydrodynamic loads were obtained after evaluating the pressure field around the multi-body configuration using three different computer codes. The results from the three computer codes compare very well with each other and with the numerical predictions of other investigators. Finally, the mean second-order drift forces are calculated by superposing their zero-current values with the corresponding current-dependent first-order corrections, with the latter being evaluated using a ‘heuristic’ approach.
Arctic Wind, Sea Ice, and the Corresponding Characteristic Relationship
Authors: Wang Kaishan , Guo Yuchen , Wu Di , Zheng Chongwei , Wu Kai
Published: September 2024

In efforts to fulfill the objectives of taking part in pragmatic cooperation in the Arctic, constructing the “Silk Road on Ice”, and ensuring ships’ safety and risk assessment in the Arctic, the two biggest hazards, which concern ships’ navigation in the Arctic, are wind and sea ice. Sea ice can result in a ship being besieged or crashing into an iceberg, endangering both human and property safety. Meanwhile, light winds can assist ships in breaking free of a sea-ice siege, whereas strong winds can hinder ships’ navigation. In this work, we first calculated the spatial and temporal characteristics of a number of indicators, including Arctic wind speed, sea-ice density, the frequency of different wind directions, the frequency of a sea-ice density of less than 20%, the frequency of strong winds of force six or above, etc. Using the ERA5 wind field and the SSMI/S sea-ice data, and applying statistical techniques, we then conducted a joint analysis to determine the correlation coefficients between the frequencies of various wind directions, the frequency of strong winds and its impact on the density of sea ice, the frequency of a sea-ice concentration (SIC) of less than 20%, and the correlation coefficient between winds and sea-ice density. In doing so, we determined importance of factoring the wind’s contribution into sea-ice analysis.
Numerical Investigation on Dynamic Response of Carbon Fiber Honeycomb Sandwich Panels Subject to Underwater Impact Load
Authors: Zheng Cheng , Wang Mingfei , Wang Yiwen , Liao Yawen , Kong Xiangshao , Wu Weiguo
Published: September 2024

This study investigates the dynamic response and failure mechanisms of carbon fiber honeycomb sandwich structures under underwater impact loads using finite element numerical simulation. The geometric modeling was performed using HyperMesh, and the dynamic response simulations were carried out in ABAQUS, focusing on honeycomb core configurations with varying edge lengths, heights, and gradient forms. The Hashin damage model was employed to describe the damage evolution of the composite materials. The simulation results revealed that the dynamic response was significantly influenced by the initial shock wave pressure and the geometrical parameters of the honeycomb cells. Larger cell-edge lengths and heights generally resulted in improved energy absorption and reduced rear panel displacement. Among the different configurations, interlayer gradient honeycomb structures demonstrated superior impact resistance compared to homogeneous and in-plane gradient structures, particularly under higher initial shock wave pressures. These findings contribute to optimizing the design of carbon fiber honeycomb sandwich structures for enhanced impact resistance in relevant applications.
Revolutionizing the Marine Spare Parts Supply Chain through Additive Manufacturing: A System Dynamics Simulation Case Study
Authors: Kostidi Evanthia , Nikitakos Nikitas
Published: September 2024

This research investigates the potential of additive manufacturing (AM) to revolutionize the marine spare parts supply chain (SPSC). While AM has been widely explored in other industries, its application in the maritime sector remains limited. This study addresses this gap by comparing traditional and AM-integrated SPSC models using system dynamics simulation. By focusing on high- and low-value spare parts, this research highlights significant cost reductions and improved delivery times through strategic AM integration. Our findings demonstrate the potential of AM to enhance the efficiency and resilience of the maritime supply chain, particularly in remote environments.
Identifying Locations for Early Adoption of Zero Emission Fuels for Shipping—The UK as a Case Study
Authors: Baresic Domagoj , Rehmatulla Nishatabbas , Smith Tristan
Published: September 2024

The United Kingdom (UK) shipping industry is facing calls to set out more robust decarbonisation plans. In light of the economic challenges facing the country, including the cost-of-living crisis and energy security considerations, the UK government has outlined plans to spearhead several ‘green’ developments. It is of paramount importance to understand how best to integrate the domestic maritime sector into this process by promoting the adoption of low-carbon marine fuels such as hydrogen and ammonia. However, there is a limited understanding of what are the most suitable locations for the early adoption of such fuels in the UK. The sustainability transitions literature offers interesting insights into how marine fuel transitions can unfold, by combining the study of market factors with various non-market socio-technical forces. Previous academic work has shown the importance of location and proximity in facilitating alternative marine fuel transitions. This paper builds onto that work by applying a socio-technical transitions framework to develop a set of indicators to ascertain the suitability of potential locations for the early adoption of hydrogen and ammonia as marine fuels in the UK. This paper explores these dynamics by combining evidence from documentary sources, a UK ship voyages database, and interviews with key stakeholders. Furthermore, three specific case studies are analysed in detail to outline key drivers for the adoption of hydrogen and ammonia. The findings show that there is a significant difference across the UK in regional viability for the early adoption of hydrogen and ammonia, with some of the best suited sites being in the north of Scotland (Orkney), south of England (the Solent-Isle of Wight), and east of England (Felixstowe-Harwich).