bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing Post-Training Muscle Recovery and Strength in Paralympic Powerlifting Athletes with Cold-Water Immersion, a Cross-Sectional Study
Authors: Aidar Felipe J. , Santos Wélia Yasmin Horacio dos , Machado Saulo da Cunha , Nunes-Silva Albená , Vieira Érica Leandro Marciano , Valenzuela Pérez Diego Ignácio , Aedo-Muñoz Esteban , Brito Ciro José , Nikolaidis Pantelis T.
Published: January 2025

(1) Background: The recovery method is important and decisive in the training system. This study aimed to assess the effects of various post-training recovery methods on muscle damage and strength indicators in Paralympic powerlifting athletes. (2) Methods: A crossover study was conducted involving eleven male athletes (25.4 ± 3.3 years, 70.3 ± 12.1 kg). Muscle damage was assessed using blood biochemical markers (cytokines IL-6, IL-10, and TNF-α) and isometric force indicators, including the maximum isometric force (MIF), time to MIF, and Rate of Force Development. The following assessments were performed before, immediately after, and at 24 and 48 h after the recovery protocol: (a) passive recovery (RP) or (b) cold-water immersion (CWI). (3) Results: The main results indicated that maximum isometric force (MIF) significantly improved after 48 h of CWI application (p < 0.05; for all comparison). The analysis of biochemical markers did not yield significant differences between the recovery methods at different time points (p > 0.05). For IL-6, there were significant differences between CWI before (2.29 ± 1.08, 95% CI 1.57–3.01) and CWI 2 h later (2 h) (4.59 ± 2.96, 95% CI 2.60–6.57; p = 0.045), and between CWI 15 min later (15 min) (4.14 ± 2.24, 95% CI 2.63–5.64) and CWI 48 h later (48 h) (2.33 ± 1.25, 95% CI 1.49–3.17; p = 0.034). There were differences between CWI 2 h (4.14 ± 2.24, 95% CI 2.63–5.64) and CWI 48 h later (2.33 ± 1.25, 95% CI 1.49–3.17; p = 0.035; F = 9.202; η2p = 0.479; high effect). (4) Conclusions: CWI significantly improved the post-resistance training muscle damage and strength in Paralympic powerlifting athletes.
Likes, Shares, and Symptoms: The Hidden Toll of Early Adolescents’ Social Media Use on Well-Being
Authors: Vonk Lisanne , Putrik Polina , van Amelsvoort Thérèse , Vanluydt Elien , Delespaul Philippe , Levels Mark , Huijts Tim
Published: January 2025

Social media use has rapidly increased over the past decade, especially among young people. To obtain more insight into the potential negative associations with problematic social media use in Dutch early adolescents, we assessed its relation to self-reported well-being. We conducted a cross-sectional study with 585 students in their final year of primary school (11–12 years old) who completed a questionnaire during school hours. We examined the association between problematic social media use and psychosomatic complaints, as well as general life satisfaction and whether perceived social support and sex moderated these associations. Problematic social media use was associated with lower general life satisfaction, as well as all psychosomatic complaints, with the strongest association for having a bad mood or feeling irritated (OR = 3.08, 99% CI = 2.05–4.63). Most associations were not moderated by perceived social support or sex. Our findings indicate that the well-being of early adolescents may be affected by problematic social media use already in primary school. The association persisted regardless of the amount of perceived social support, and without strong gender differences. This suggests that the potential for limiting the potential negative consequences of problematic social media use through increasing social support is limited.
Spatiotemporal Changes and Trade-Offs/Synergies of Ecosystem Services in the Qin-Mang River Basin
Authors: Zhao Jiwei , Wang Luyao , Jia Dong , Wang Yaowen
Published: January 2025

The Qin-Mang River Basin is an important biodiversity conservation area in the Yellow River Basin. Studying the spatiotemporal changes in its ecosystem services (ESs) and the trade-offs and synergies (TOSs) between them is crucial for regional ecological protection and high-quality development. This study, based on land use type (LUT), and meteorological and soil data from 1992 to 2022, combined with the InVEST model, correlation analysis, and spatial autocorrelation analysis, explores the impacts of land use/land cover changes (LUCCs) on ESs. The results show that: (1) driven by urbanization and economic development, the expansion of built-up areas has replaced cultivated land and forests, with 35,000 hectares of farmland lost, thereby increasing pressure on ESs; (2) ESs show an overall downward trend, habitat quality (HQ) has deteriorated, carbon storage (CS) remains stable but the area of low CS has expanded, and sediment delivery ratio (SDR) and water yield (WY) fluctuate due to human activities and climate influence; (3) the TOSs of ESs change dynamically, with strong synergies among HQ, CS, and SDR. However, in areas with water scarcity, the negative correlation between HQ and WY has strengthened; (4) spatial autocorrelation analysis reveals that in 1992, significant positive synergies existed between ESs in the northern and northwestern regions, with WY negatively correlated with other services. By 2022, accelerated urbanization has intensified trade-off effects in the southern and eastern regions, leading to significant ecological degradation. This study provides scientific support for the sustainable management and policymaking of watershed ecosystems.
Evaluating Mobile Telecom Apps: An Integrated Fuzzy MCDM Model Using Marketing Mix
Authors: Alabool Hamzeh Mohammad
Published: January 2025

App-based marketing has been widely used in the telecommunications industry to both serve and draw in new customers. Typically, telecom providers must invest an amount of company resources to develop and maintain the operations mechanism of information technology platforms (e.g., mobile apps); therefore, it is important to take the issue of marketing effectiveness into account. For example, the mismatch between what telecom providers offer in their mobile apps and customers’ marketing requirements plays a significant role in determining unmet knowledge and presentation gaps that are related to the marketing domain. This research intends to propose an integrated Fuzzy MCDM model based on 4Ps (Product, Price, Place, Promotion) and 4Cs (Customer Needs, Cost, Convenience, Communication) models for evaluating mobile telecom applications (MTAs). Therefore, the 4Ps and 4Cs models are extended to develop a hierarchy model for evaluating MTAs. Next, fuzzy theory is applied to handle the subjectiveness of qualitative evaluation criteria while the Analytic Hierarchy Process (AHP) is applied to synthesize the weight and score of the evaluation criteria. The proposed model is applied to evaluate, rank, and analyze the MTA of three telecom providers in the Kingdom of Saudi Arabia (KSA) (e.g., STC, Zain, and Mobily). The conducted case study ensures the usability and applicability of the proposed model. The evaluation results offer several managerial actions for achieving ideal app-based marketing.
Functional Responses of the Warehouse Pirate Bug Xylocoris flavipes (Reuter) (Hemiptera: Anthocoridae) on a Diet of Liposcelis decolor (Pearman) (Psocodea: Liposcelididae)
Authors: Bosomtwe Augustine , Opit George , Giles Kristopher , Kard Brad , Goad Carla
Published: January 2025

Psocids are difficult to manage using grain protectants and phosphine hence research on non-chemical control methods. This study evaluated the effectiveness of Xylocoris flavipes (Reuter) (Hemiptera: Anthocoridae) at managing Liposcelis decolor (Pearman) (Psocodea: Liposcelididae). The functional responses of adult♀ and nymphs of X. flavipes on a diet of nymphs, adult♂, and adult♀ of L. decolor were determined under laboratory conditions at 28 ± 1 °C, 63 ± 5% RH, and a 0:24 (L:D) photoperiod. Maximum likelihood estimates (MLEs) of a logistic regression analysis showed that the functional responses of the life stages of X. flavipes on diets of three stages of L. decolor were Holling Type II. Estimates of the attack rate (a), handling time (Th), maximum predation (K) per day, and predation efficiency (η) per day for the two predator life stages against each prey life stage showed that the adult♀ X. flavipes predation rate was better compared with the nymphs. The adult♀ X. flavipes per capita consumption rate and searching efficiency were also higher than those of the nymphs. The data showed adults of L. decolor are more favorable for adult♀ X. flavipes whereas their nymphs prefer nymphs of L. decolor. Field evaluation of X. flavipes is required for their incorporation into psocid pest management.
Alcohol, Tobacco and Illicit Drug Use During Pregnancy in the Longitudinal BELpREG Cohort in Belgium Between 2022 and 2024
Authors: Lenie Sien , Sillis Laure , Allegaert Karel , Bogaerts Annick , Smits Anne , Van Calsteren Kristel , Verbakel Jan Y. , Foulon Veerle , Ceulemans Michael
Published: January 2025

Background/Objectives: Substance use during pregnancy is associated with adverse outcomes for both mother and child. This study aimed to determine the prevalence and determinants of alcohol, tobacco and illicit drug use before and during pregnancy in Belgium. Methods: An observational study was conducted using data from the longitudinal BELpREG registry. The study included women aged 18 years or older who completed at least one questionnaire on substance use during pregnancy between 2022 and 2024. Data were analyzed using descriptive statistics and logistic regressions. Results: In total, 1441 women were included. Preconception prevalences of alcohol, tobacco and illicit drug use were 82.2%, 10.0% and 4.2%. These self-reported prevalences dropped in the first trimester to 12.9%, 4.1% and 0.6%, respectively. Considering the rates of substance use in pregnancy but before pregnancy awareness, the overall prevalence of alcohol, tobacco and illicit drug use in the first trimester was 41.0%, 6.6% and 1.2%, respectively. Women with a higher education (aOR (adjusted odds ratio), 2.12; 95% CI (confidence interval): 1.14–3.96), unplanned pregnancies (aOR, 2.88; 95% CI: 1.77–4.67), spontaneous pregnancies (aOR, 2.94; 95% CI: 1.51–5.75), cohabitants drinking alcohol daily (aOR, 2.01; 95% CI: 1.09–3.70), and those using tobacco in the first trimester (aOR, 5.37; 95% CI: 2.70–10.66) were more likely to report alcohol use. In addition, women with a lower education (aOR, 7.67; 95% CI: 3.76–15.67), unplanned pregnancies (aOR, 3.31; 95% CI: 1.53–7.15), cohabitants using tobacco (aOR, 9.11; 95% CI: 4.48–18.52), and those who used alcohol (aOR, 6.67; 95% CI: 3.07–14.64) or illicit drugs (aOR, 39.03; 95% CI: 3.72–409.83) in the first trimester were more likely to report tobacco use. Conclusions: Despite a significant reduction in substance use in pregnancy compared to before pregnancy, a relevant portion of women continue to use substances, particularly in the early stages before pregnancy awareness. Targeted public health interventions and (more) awareness among caregivers are needed to further promote substance use cessation before conception.
Healthcare Professionals’ Perspectives on Sepsis Care Pathways—Qualitative Pilot Expert Interviews
Authors: Draeger Lea , Fleischmann-Struzek Carolin , Bleidorn Jutta , Kannengiesser Lena , Schmidt Konrad , Apfelbacher Christian , Matthaeus-Kraemer Claudia
Published: January 2025

Background/Objectives: Despite recent decades’ rapid advances in the management of patients with sepsis and septic shock, global sepsis mortality and post-acute sepsis morbidity rates remain high. Our aim was, therefore, to provide a first overview of sepsis care pathways as well as barriers and supportive conditions for optimal pre-clinical, clinical, and post-acute sepsis care in Germany. Methods: Between May and September 2023, we conducted semi-structured, video-based, one-to-one pilot expert interviews with healthcare professionals representing pre-hospital, clinical, and post-acute care settings. The interviews were audio-recorded, transcribed verbatim, and analyzed according to the principles of Mayring’s content analysis. Results: The eight interviewed professionals identified perceived critical success factors along the entire care pathway with regard to early detection (e.g., disease awareness), early acute treatment (e.g., unknown origin of infection), rehabilitation/aftercare (e.g., availability of primary care actors), and patient transitions within and between sectors (e.g., advance notice of patient arrival). These critical factors comprised: (1) the characteristics of the staff providing care (e.g., available experience), (2) the aids/utilities used (e.g., SOPs), (3) the presentation of the disease (e.g., clear symptoms), (4) the workplace (e.g., high workload), and (5) the cooperation between the staff caring for the patient (e.g., announced and standardized handovers). Conclusions: Apart from the specific recommendations that can be derived from the individual factors presented, it can be summarized that all levels of care seem only to be purposeful if providers collaborate and communicate efficiently (i.e., correct triage, multiple-eye principle, transfer management, provision of content-rich medical/discharge letters).
Three-Dimensional Posture Analysis-Based Modifications After Manual Therapy: A Preliminary Study
Authors: Scoppa Fabio , Graffitti Andrea , Pirino Alessio , Piermaria Jacopo , Tamburella Federica , Tramontano Marco
Published: January 2025

Background/Objectives: Manual therapies like Osteopathic Manipulative Treatment (OMT) and Gentle Touch Intervention (GTI) are widely employed for improving posture and spinal alignment, but their effects as measured using advanced technologies remain underexplored. This study aims to evaluate the short-term postural effects of these interventions using a non-invasive three-dimensional rasterstereography-based approach, focusing on the cervical arrow, lumbar arrow, kyphotic angle, and lordotic angle parameters. Methods: A three-armed randomized controlled trial was conducted with 165 healthy participants. The subjects were divided into control (CTRL), OMT, and GTI groups. Their postural parameters were assessed pre- and post-intervention using the Spine3D system by Sensor Medica (Guidonia Montecelio, Italy). The statistical analyses included paired t-tests and an ANOVA, with the significance set at p < 0.05. Results: Significant reductions in the cervical arrow were observed in both the OMT (p < 0.005) and GTI (p < 0.05) groups, while the kyphotic angle significantly improved only in the GTI group (p < 0.05). No significant changes were found in the lumbar arrow or the lordotic angle across the groups. The control group showed no postural variations, reinforcing the specificity of the interventions. Conclusions: Both OMT and GTI influence spinal posture, particularly in the cervical and thoracic regions. GTI, with its gentle approach, demonstrated unique effects on the thoracic curvature, suggesting neurophysiological mechanisms. These findings highlight the potential of manual therapies for posture modulation and suggest future research should explore their long-term benefits and applications in clinical populations.
RF Dielectric Permittivity Sensing of Molecular Spin State Switching Using a Tunnel Diode Oscillator
Authors: Soroceanu Ion , Diaconu Andrei , Ciobanu Viorela-Gabriela , Salmon Lionel , Molnár Gábor , Rotaru Aurelian
Published: January 2025

We introduce a novel approach to study the dielectric permittivity of spin crossover (SCO) molecular materials using a radio frequency (RF) resonant tunnel diode oscillator (TDO) circuit. By fabricating a parallel plate capacitor using SCO particles embedded into a polymer matrix as an integral part of the inductor (L) capacitor (C) LC tank of the TDO, we were able to extract the temperature dependence of the dielectric permittivity of frequency measurements for a wide selection of resonance values, spanning from 100 kHz up to 50 MHz, with great precision (less than 2 ppm) and in a broad temperature range. By making use of this simple electronic circuit to explore the frequency and temperature-dependent dielectric permittivity of the compound Fe[(Htrz)2(trz)](BF4), we demonstrate the reliability and resolution of the technique and show how the results compare with those obtained using complex instrumentation.
Physical Foam Injection Molding of Cellulose Fiber Reinforced Polypropylene by Using CO2: Parameter Variation and Comparison to Chemical Foam Injection Molding
Authors: Pretschuh Claudia , Mihalic Matthias , Sponner Christian , Lummerstorfer Thomas , Steurer Andreas , Unterweger Christoph
Published: January 2025

The use of cellulose fiber-filled polypropylene (PP) composites in combination with foam injection molding has enabled the lightweight design of injection-molded parts. The study provides achievements for the physical foam injection molding (MuCell®) process of PP–cellulose fiber compounds by using CO2 as the direct foaming agent, including a comparison of MuCell® foaming with N2 and a comparison to a chemical foaming process. Weight and density reductions, foam structure and specific mechanical properties are highly dependent on the applied processing parameters. The maximum weight reduction reached values of up to 16%, and density reduction even reached 33% in relation to the compact plates. The extent of weight and density reduction could be adjusted, among other factors, by a reduction in the shot volume. Setting the density reduction to 22% allowed for simultaneously decreasing weight while sustaining the specific flexural properties and limiting the loss of specific impact strength. By using optimized FIM parameters, the mechanical performance could be improved, with specific modulus values even outperforming the compact reference sample. This presents a significant benefit for the preparation of lightweight products and sets the basis for further optimization and modeling studies.
Virus-Mimicking Polymer Nanocomplexes Co-Assembling HCV E1E2 and Core Proteins with TLR 7/8 Agonist—Synthesis, Characterization, and In Vivo Activity
Authors: Fuerst Thomas R. , Marin Alexander , Jeong Sarah , Kulakova Liudmila , Hlushko Raman , Gorga Katrina , Toth Eric A. , Singh Nevil J. , Andrianov Alexander K.
Published: January 2025

Hepatitis C virus (HCV) is a major public health concern, and the development of an effective HCV vaccine plays an important role in the effort to prevent new infections. Supramolecular co-assembly and co-presentation of the HCV envelope E1E2 heterodimer complex and core protein presents an attractive vaccine design strategy for achieving effective humoral and cellular immunity. With this objective, the two antigens were non-covalently assembled with an immunostimulant (TLR 7/8 agonist) into virus-mimicking polymer nanocomplexes (VMPNs) using a biodegradable synthetic polyphosphazene delivery vehicle. The resulting assemblies were characterized using dynamic light scattering and asymmetric flow field-flow fractionation methods and directly visualized in their vitrified state by cryogenic electron microscopy. The in vivo superiority of VMPNs over the individual components and an Alum-formulated vaccine manifests in higher neutralizing antibody titers, the promotion of a balanced IgG response, and the induction of a cellular immunity—CD4+ T cell responses to core proteins. The aqueous-based spontaneous co-assembly of antigens and immunopotentiating molecules enabled by a synthetic biodegradable carrier offers a simple and effective pathway to the development of polymer-based supramolecular nanovaccine systems.
Structural Response Prediction of Floating Offshore Wind Turbines Based on Force-to-Motion Transfer Functions and State-Space Models
Authors: Xu Jie , Li Changjie , Jiang Wei , Lin Fei , Liu Shi , Lu Hongchao , Wang Hongbo
Published: January 2025

This paper proposes an innovative algorithm for forecasting the motion response of floating offshore wind turbines by employing force-to-motion transfer functions and state-space models. Traditional numerical integration techniques, such as the Newmark-β method, frequently struggle with inefficiencies due to the heavy computational demands of convolution integrals in the Cummins equation. Our new method tackles these challenges by converting the problem into a system output calculation, thereby eliminating convolutions and potentially enhancing computational efficiency. The procedure begins with the estimation of force-to-motion transfer functions derived from the hydrostatic and hydrodynamic characteristics of the wind turbine. These transfer functions are then utilized to construct state-space models, which compactly represent the system dynamics. Motion responses resulting from initial conditions and wave forces are calculated using these state-space models, leveraging their poles and residues. We validated the proposed method by comparing its calculated responses to those obtained via the Newmark-β method. Initial tests on a single-degree-of-freedom (SDOF) system demonstrated that our algorithm accurately predicts motion responses. Further validation involved a numerical model of a spar-type floating offshore wind turbine, showing high accuracy in predicting responses to both regular and irregular wave conditions, closely aligning with results from conventional methods. Additionally, we assessed the efficiency of our algorithm over various simulation durations, confirming its superior performance compared to traditional time-domain methods. This efficiency is particularly advantageous for long-duration simulations. The proposed approach provides a robust and efficient alternative for predicting motion responses in floating offshore wind turbines, combining high accuracy with improved computational performance. It represents a promising tool for enhancing the development and evaluation of offshore wind energy systems.
Multi-Objective Optimization of Ship Design for the Effect of Wind Propulsion
Authors: Plessas Timoleon , Papanikolaou Apostolos
Published: January 2025

International regulations and market demand for zero-emission transportation are accelerating the adoption of sustainable solutions in the shipping industry. Wind-Assisted Propulsion Systems (WAPSs) present a promising alternative, as elaborated on in the EU-funded Orcelle Wind project. This paper deals with the integration of wing sails into the conceptual design of a Very Large Crude Carrier (VLCC) using a parametric, multi-objective optimization framework. The results reveal that optimized VLCC designs with WAPSs can achieve over 20% reductions in fuel consumption and greenhouse gas emissions compared to conventional designs. Additionally, the obtained optimized designs exhibit notable differences in the main design characteristics and hull form compared to conventional designs, highlighting the importance of multi-objective optimization in the early design stage to tap the potential of WAPS technologies and wind propulsion.
The Formation and Modification of the Arcuate Tectonic Belt in the Northeastern Tibetan Plateau: Insight from Three-Dimensional Finite Element Numerical Simulation
Authors: Zhao Yilin , Shi Wei , Sun Yujun , Hou Guiting
Published: January 2025

The arcuate tectonic belt in the northeast Tibetan Plateau has been a contentious topic regarding its formation and evolution, owing to its distinctive geological structure as the lateral growth boundary of the plateau. In this research, leveraging geological and geophysical data, a three-dimensional finite element numerical model is employed to explore the impact of lateral and vertical inhomogeneities in lithospheric strength on the northeast Tibetan Plateau’s growth and the arcuate tectonic belt’s formation and alteration. Additionally, the kinematic and deformation traits of the arcuate tectonic belt, such as regional motion velocity, stress, and crustal thickness during shortening and strike-slip deformation, are comparatively analyzed. The findings indicate that the arcuate tectonic belt takes shape when the weakly strengthened Tibetan Plateau is impelled into the Yinchuan Basin after being obstructed by the robust Alax and Ordos blocks during lateral expansion. Intense shear deformation occurs at the block boundaries during the arc tectonic belt’s formation. The weak middle-lower crust, serving as a detachment layer, facilitates the plateau’s lateral growth and crustal shortening and thickening without perturbing the overall deformation characteristics. It is verified that the arcuate tectonic belt was formed during the NE-SW compression phase from around 9.5 to 2.5 Ma, accompanied by significant crustal shortening and thickening. Since 2.5 Ma, within the ENE-WSW compression process, the internal faults of the arcuate tectonic belt are predominantly strike-slip, with no pronounced crustal shortening and thickening. Only local topographical modification is conspicuous. This study will enhance our comprehension of the Tibetan Plateau’s uplift and lateral growth process and furnish a foundation for investigating the formation of arcuate tectonic belts.
Ship Collision Risk Assessment Algorithm Based on the Especial Cautious Navigation Angle Model
Authors: Pan Wei , Wang Yukuan , Xie Xinlian , Li Meng , Fan Jinru
Published: January 2025

To address the challenges posed by dense shipping traffic and the difficulty of identifying navigation risks in open waters, this paper introduces an Especial Cautious Navigation Angle (ECNA) model for ships, grounded in ship collision avoidance geometry. The ECNA model dynamically identifies the range of navigation angles where collision risks may arise between ships. Building upon this model, a comprehensive scoring algorithm is proposed to assess ship collision risks in open waters. This algorithm not only effectively tracks the evolving risk of collisions but also prioritizes ships with the most imminent danger of collision. Experimental results demonstrate that the ECNA model can accurately define the range of collision risk navigation angles. Furthermore, the scoring algorithm provides a quantitative analysis of the development trends in collision risks and offers continuous monitoring of these risks during navigation in open waters. The proposed model and algorithm exhibit strong practical applicability and operability in identifying ship collision risks in both open and dense navigable areas. These findings not only offer valuable guidance for real-world collision risk identification but also contribute to the theoretical advancement of ship collision risk analysis, presenting a novel solution to this pressing issue.
Exploring the Potential of Posidonia oceanica Fibers in Eco-Friendly Composite Materials: A Review
Authors: Fragassa Cristiano , Pesic Ana , Mattiello Sara , Pavlovic Ana , Santulli Carlo
Published: January 2025

The growing demand for sustainable materials has driven the exploration of natural fibers as eco-friendly alternatives to synthetic reinforcements for composites. This study investigates the potential of Posidonia oceanica, an abundant marine biomass, which is often driven to be stacked on the backshore and used so far for energy recovery and low-value applications, as a filler and possible reinforcement in cementitious and polymer composites. Most applications of Posidonia are concentrated in the Mediterranean area and focused on the construction industry. However, its introduction in polymer composites, especially as a source of cellulose or in combination with the use of bio-based matrices, can also be proposed. With this aim, the physical and chemical properties of Posidonia oceanica fibers need to be characterized, and their compatibility with various matrices needs to be evaluated. Experimental results demonstrate that Posidonia oceanica fibers, especially when treated with alkali and silane, or combining both treatments, can exhibit mechanical properties quite comparable to other natural fibers, namely to those obtained from grass species. As with any other type of waste, yet with more interest for its wide accumulation over the coastal line, the use of Posidonia oceanica in composites may contribute to reducing the environmental footprint of these materials, aligning with circular economy principles. This review highlights the dual benefits of utilizing marine biomass by advancing material sustainability while not being detrimental to coastal waste management.
Improvement of Propeller Hydrodynamic Prediction Model Based on Multitask ANN and Its Application in Optimization Design
Authors: Li Liang , Chen Yihong , Huang Lu , Hai Qing , Tang Denghai , Wang Chao
Published: January 2025

A multitask learning (MTL) model based on artificial neural networks (ANNs) is proposed in this study to improve the prediction accuracy and physical reliability of marine propeller hydrodynamic performance. The propeller’s comprehensive geometric features are used as inputs, and the coefficients of quadratic polynomials for the thrust coefficient (KT) and torque coefficient (10KQ) curves are predicted as outputs. The loss function is customized through a positive gradient penalty of the curves to accelerate training. When the single-task and multitask models were compared, the prediction errors were reduced; KT decreased from 2.61% to 2.07%, 10 KQ decreased from 3.58% to 2.31%, and the efficiency (η) decreased from 3.04% to 2.00%. Non-physical fluctuations in the performance curves were effectively mitigated by the multitask model, yielding predicted curvatures which closely matched the experimental data. Strong generalization was demonstrated when the model was tested on unseen propellers, with deviations of 2.2% for KT, 4.6% for 10 KQ, and 3.8% for η. Finally, the model was applied to optimize the propeller design for a 325,000 ton very large ore carrier ship, where a Pareto front with 58 non-dominant solutions for the maximum speed and fluctuating pressure was successfully generated and effectively verified by the model’s test results. The model enhanced the prediction of the propeller performance and contributed to optimization in the propeller’s design.
Spatiotemporal Relationship Between Carbon Metabolism and Ecosystem Service Value in the Rural Production–Living–Ecological Space of Northeast China’s Black Soil Region: A Case Study of Bin County
Authors: Shang Yajie , Chen Yuanyuan , Zhai Yalin , Wang Lei
Published: January 2025

Amid global climate challenges and an urgent need for ecological protection, the northeastern black soil region—one of the world’s remaining “three major black soil regions”—confronts significant tensions between agricultural economic development and land ecological protection, threatening national food security. Based on the “production–ecology–life” (PLE) classification system, this study established a dual-dimensional evaluation for carbon metabolism and ESV in horizontal and vertical dimensions. The horizontal flow of carbon and ESV was traced across different ecosystems, while the spatial and temporal dynamics of carbon metabolism and ESV were analyzed vertically. Spatial autocorrelation analyses were employed to examine the interaction patterns between carbon metabolism and ESV. The findings reveal that (1) cropland production space remains the dominant spatial type, exhibiting fluctuating patterns in the size of other spatial types, with a notable reduction in water ecological space. (2) From 2000 to 2020, high-value carbon metabolism density areas were primarily concentrated in the central region, while low-value areas gradually decreased in size. Cropland production space and urban living space served as key compartments and dominant pathways for carbon flow transfer in the two periods, respectively. (3) The total ecosystem service value (ESV) showed a downward trend, decreasing by CNY 1.432 billion from 2000 to 2020. The spatial distribution pattern indicates high values in the center and northwest, contrasting with lower values in the southeast. The flow of ecological value from forest ecological space to cropland production space represents the main loss pathway. (4) A significant negative correlation exists between carbon metabolism density and ESV, with areas of high correlation predominantly centered around cropland production space. This study provides a scientific foundation for addressing the challenges facing the black soil region, achieving synergistic resource use in pursuit of carbon neutrality, and constructing a more low-carbon and sustainable spatial pattern.
Influence of Microstructure on Music Properties of SWP-B Music Steel Wire Under Different Annealing Treatments
Authors: Jia Xinru , Li Qinghua , Li Fuguo , Fang Xiaohui , You Junda , Zhao Qian , Wang Xia , Lu Jinhua
Published: January 2025

The mechanical properties of music wire are contingent upon its microstructure, which in turn influences its applications in music. Chinese stringed instruments necessitate exacting standards for comprehensive performance indexes, particularly with regard to the strength, resilience, and rigidity of the musical steel wires, which differ from the Western approach to musical wire. In this study, SWP-B music wire was selected for investigation through metal heat treatment, which was employed to regulate its microstructure characteristics. Furthermore, a spectral analysis was conducted to evaluate the musical expression, encompassing attributes such as pitch and timbre. In conclusion, the governing law of the impact of the microstructure of music wire on its musical expression was established. The results demonstrate that steel wire subjected to a 200 °C annealing treatment for cementite spheroidization can effectively reduce stress concentration, thereby reducing the probability of fracture and consequently improving tonal uniformity and richness while increasing tensile strength from 2578 MPa to 2702 MPa. Conversely, the high-temperature annealing treatment alters the crystalline structure of the material and refines the grain structure, thereby improving the material’s performance and sound quality. The fine microstructure of the music steel wire displays enhanced uniformity. As the annealing temperature increases, the strength of the ferrite phase <110>//ND (<010>//ND, indicating that the <010> direction of the crystal is parallel to the normal direction of the material) and the cementite phase <010>//ND demonstrates a gradual decline. However, this also results in a more pronounced harmonic performance, which, in turn, affects the overall music expression.
Enhancing Reciprocating Wear Resistance of Co37Cr28Ni31Al2Ti2 Spark Plasma Sintered Medium-Entropy Alloy via TiC Addition
Authors: Zhao Yubo , Ma Wenbo , Tisov Oleksandr
Published: January 2025

The aim of this paper is to investigate the effect of TiC addition on the microstructure, microhardness, and wear resistance of the medium-entropy alloy Co37Cr28Ni31Al2Ti2, which is suitable for applications in aerospace, automotive, and energy industries due to its high strength and wear resistance. The samples containing 0, 10, 20, and 40 wt.% of TiC were synthesized. The alloy’s microstructure changes significantly with the addition of TiC particles: they are uniformly dispersed in the FCC matrix, effectively increasing the Vickers hardness from 439 HV for the base alloy to 615 HV for the 40% TiC alloy. The four alloys were subjected to reciprocating dry sliding friction tests at loads of 2 N, 5 N, and 10 N. The wear volumes of the base alloy at these loads were 2.7 × 107, 4.6 × 107, and 1.1 × 108 μm3, respectively. The experimental results indicate that adding TiC greatly improves the wear resistance of the alloy by increasing the hardness and forming an oxide protective film. This study highlights the potential for developing alloys with excellent tribological properties for demanding application scenarios.
Development of 17-4 PH Stainless Steel for Low-Power Selective Laser Sintering
Authors: Chao Yu-Deh , Liu Shu-Cheng , Chen Fu-Lin , Prajapati Mayur Jiyalal , Kumar Ajeet , Tsai Jung-Ting , Jeng Jeng-Ywan
Published: January 2025

Selective laser sintering (SLS) is one of the prominent methods of polymer additive manufacturing (AM). A low-power laser source is used to directly melt and sinter polymer material into the desired shape. This study focuses on the utilization of the low-power laser SLS system to successfully manufacture metallic components through the development of a metal–polymer composite material. In this study, 17-4 PH stainless powders are used and mixed with polyoxymethylene (POM) and high-density polyethylene (HDPE) to prepare the composite powder material. The polymeric mixture is removed during the thermal degreasing process and subsequent sintering results in a solid metallic component. Sinterit Lisa with a 5 W, 808 nm laser source is used to fabricate the green part. For the printing parameters of 140 °C, laser power of 35.87 mJ/mm2, and layer thickness of 100 μm, the printed samples achieved a maximum density of 3.61 g/cm3 and a complete shape. After sintering at 1310 °C for 180 min, the tensile strength of the shrunk sample is 605.64 MPa, the hardness is HRC 14.8, the average shrinkage rate is 22%, and the density is 7.57 g/cm3, which can reach 97% of the theoretical density. This process allows the use of a wide range of particle sizes that the usual AM technologies have, making it a low-cost, low-energy-consumption, high-speed AM technology.
Mechanical Strength and Mechanism Analysis of Silt Soil Cured by Straw Ash–Calcium Carbide Slag
Authors: Huang Yue , Xu Wenyuan , Ji Yongcheng , Yang Liang
Published: January 2025

Large-scale engineering projects frequently involve pit excavation and wetland landfill operations, resulting in significant silt accumulation that occupies land and adversely affects the environment. Curing technology offers a solution for reusing this waste silt. In this study, straw ash and calcium carbide slag are proposed as effective curing agents for silt soil. Various indoor tests were conducted to evaluate the mechanical properties of the cured silt soil, while X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze its mineral composition and micro-morphology. The results showed that increasing the curing agent dosage significantly improved soil strength. Specifically, at a 10% dosage, the California bearing ratio (CBR) value increased to 18.7%, which is 13.4 times higher than untreated silt soil and exceeds road specifications by 8%. At a 20% dosage, the unconfined compressive strength (UCS) value reached 1.38 MPa, meeting the ≥0.8 MPa requirement for roadbeds. Based on economic considerations, a 20% dosage of straw ash–calcium carbide slag was selected as optimal. Microscopic analysis revealed that the addition of these agents promoted the formation of hydrated calcium silicate, filling pores and enhancing the mechanical properties of the cured soil, resulting in a more dense and stable structure.
Simplified Model for the Behaviour of Asphalt Mixtures Depending on the Time and the Frequency Domain
Authors: Primusz Péter , Tóth Csaba
Published: January 2025

Sigmoid functions are widely used for the description of viscoelastic material properties of asphalt mixtures. Unfortunately, there are still no known closed functions for describing connections among model parameters in the time and the frequency domains. In most cases, complicated interconversion methods are applied for the conversion of viscoelastic material properties. To solve this problem, an empirical material model with four parameters has been developed. Parameters of the model can be quickly determined in the frequency domain and can be used in an unchanged way for the description of the material behaviour of the asphalt mixture in the time domain. The new model starts from the mathematical formula of the Ramberg–Osgood material model (short form RAMBO) and its main advantage is that its parameters are totally independent. Model calculations have been performed for the determination of factors necessary for the interconversion in the time and the frequency domains, applying the approximate procedure of Ninomiya and Ferry. The analysis of data has indicated that the interconversion factors in the time and the frequency domains depend only on the slope of the new empirical model function. Consequently, there is no need for further calculations, since the RAMBO model parameters determined in the frequency domain provide an excellent characterisation of the analysed mixture in the time domain as well. The developed new empirical material model has been verified using laboratory data and exact numerical calculations.
A Hybrid Dynamic Principal Component Analysis Feature Extraction Method to Identify Piston Pin Wear for Binary Classifier Modeling
Authors: Yang Hao , Zhai Yubin , Zheng Mengkun , Wang Tan , Guo Dongliang , Liang Jianhui , Li Xincheng , Liu Xianliang , Jia Mingtao , Zhang Rui
Published: January 2025

The wear condition of a piston pin is a main factor in determining the operational continuity and life cycle of a diesel engine; identifying its vibration feature is of paramount importance in carrying out necessary maintenance in the early wear stage. As the dynamic vibration features are susceptible to environmental disturbance during operation, an effective signal processing method is necessary to improve the accuracy and fineness of the extracted features, which is essential to build a reliable and precise binary classifier model to identify piston pin wear based on the features. Aiming at the feature extraction requirements of anti-noise, accuracy and effectiveness, this paper proposes a piston pin wear feature extraction algorithm based on dynamic principal component analysis (DPCA) combined with variational mode decomposition (VMD) and singular value decomposition (SVD). An orthogonal sensor layout is applied to collect the vibration signal under normal and worn piston pin conditions, which proved effective in reducing environmental vibration disturbance. DPCA is utilized to extract dynamical vibration features by introducing time lag. Then, the dynamic principal component matrix is further decomposed by VMD to obtain intrinsic mode functions (IMFs) as finer features and is finally decomposed by SVD to compress the features, thus improving the classification efficiency based on the features. To validate the significance of the features extracted by the proposed method, a support vector machine (SVM) is employed to model binary classifiers to evaluate the classification performance trained by different features. A modeling dataset containing 80 samples (40 normal samples and 40 worn samples) is employed, and five-round cross-validation is adopted. For each round, two binary classifier models are trained by features extracted by the proposed method and the empirical mode decomposition (EMD)–auto regressive (AR) spectrum method, fast Fourier transform (FFT) and continuous wavelet transform (CWT), respectively; the classification precision, recall ratio, accuracy and F1 ratio are obtained on the testing set by contrasting the overall performances of the five-round cross-validation, and the proposed method is proved to be more effective in noise reduction and significant feature extraction, which is able to improve the accuracy and efficiency of binary classification for piston pin wear identification.
Unsupervised Word Sense Disambiguation Using Transformer’s Attention Mechanism
Authors: Ion Radu , Păiș Vasile , Mititelu Verginica Barbu , Irimia Elena , Mitrofan Maria , Badea Valentin , Tufiș Dan
Published: January 2025

Transformer models produce advanced text representations that have been used to break through the hard challenge of natural language understanding. Using the Transformer’s attention mechanism, which acts as a language learning memory, trained on tens of billions of words, a word sense disambiguation (WSD) algorithm can now construct a more faithful vectorial representation of the context of a word to be disambiguated. Working with a set of 34 lemmas of nouns, verbs, adjectives and adverbs selected from the National Reference Corpus of Romanian (CoRoLa), we show that using BERT’s attention heads at all hidden layers, we can devise contextual vectors of the target lemma that produce better clusters of lemma’s senses than the ones obtained with standard BERT embeddings. If we automatically translate the Romanian example sentences of the target lemma into English, we show that we can reliably infer the number of senses with which the target lemma appears in the CoRoLa. We also describe an unsupervised WSD algorithm that, using a Romanian BERT model and a few example sentences of the target lemma’s senses, can label the Romanian induced sense clusters with the appropriate sense labels, with an average accuracy of 64%.
Accurate Computations with Generalized Pascal k-Eliminated Functional Matrices
Authors: Delgado Jorge , Orera Héctor , Peña Juan Manuel
Published: January 2025

This paper presents an accurate method to obtain the bidiagonal decomposition of some generalized Pascal matrices, including Pascal k-eliminated functional matrices and Pascal symmetric functional matrices. Sufficient conditions to assure that these matrices are either totally positive or inverse of totally positive matrices are provided. In these cases, the presented method can be used to compute their eigenvalues, singular values and inverses with high relative accuracy. Numerical examples illustrate the high accuracy of our approach.
Linear Jointly Disjointness-Preserving Maps Between Rectangular Matrix Spaces
Authors: Li Ru-Jheng , Lin Yu-Ju , Tsai Ming-Cheng , Wang Ya-Shu
Published: January 2025

This paper studies pairs of linear maps that preserve the disjointness of matrices in rectangular matrix spaces. We present a complete characterization of all pairs of bijective linear maps that jointly preserve disjointness. Additionally, we apply these results to study maps that preserve specific matrix properties, such as the double-zero product property.
Analysis and Control of Rumor Propagation Model Considering Multiple Waiting Phases
Authors: Wu Hai , Yan Xin , Gao Shengxiang , Deng Zhongying , Chi Haiyang
Published: January 2025

Rumors pose serious harm to society and exhibit a certain degree of repetitiveness. Existing rumor propagation models often have simple rules and neglect the repetitiveness of rumors. Therefore, we propose a new SCWIR rumor propagation model (susceptible, commented, waited, infected, recovered) by introducing the user’s repeated waiting behavior to simulate the potential for rumors to lie dormant and spread opportunistically. First, we present the dynamic equations of the model, then introduce three influencing factors to improve the model. Next, by solving for the equilibrium points and the basic reproduction number, we discuss the local and global stability of the rumor-free/rumor equilibrium points. Finally, we perform numerical simulations to analyze the effects of different factors on rumor propagation. The results show that the introduction of the multiple waiting mechanism helps simulate the repetitiveness of rumor propagation. Among the rumor suppression strategies, the effectiveness, from highest to lowest, is as follows: government intervention, information dissemination and popularization, and accelerated rumor value decay, with government intervention playing a decisive role. Information dissemination can reduce the intensity of rumors at the source.
CR-Selfdual Cubic Curves
Authors: Crasmareanu Mircea , Pripoae Cristina-Liliana , Pripoae Gabriel-Teodor
Published: January 2025

We introduce a special class of cubic curves whose defining parameter satisfies a linear or quadratic equation provided by the values of a cross ratio. There are only seven such cubics and several properties of the real cubics in this class (some of them being elliptic curves) are discussed. Using the Möbius transformation, we extend this self-duality and obtain new families of remarkable complex cubics. In addition, we study (from the differential geometric viewpoint) the surface parameterized by all real cubic curves and we derive its curvature functions. As a by-product, we find a new classification of real Möbius transformations and some estimates for the number of vertices of real cubic curves.