bluuebunny/crossref_metadata_2025 huggingface dataset:
How Does High-Standard Farmland Construction Affect Agroecological Efficiency—From the Perspective of Factor Endowment
Authors: Ren Jin , Chen Xinrui , Miao Zimeng , Gao Tingting
Published: October 2024

Based on the factor endowment theory and the agriculture-induced technological innovation theory, this study examines the impact of high-standard farmland construction (HFC) on agricultural ecological efficiency (AEE) and sustainable agricultural development. Using empirical data from 30 provinces in China between 2005 and 2022, it explores how high-standard farmland construction techniques can enhance AEE, considering factor endowment preferences and geographical characteristics. Empirical research indicates that high-standard farmland significantly enhances AEE, particularly in the eastern region, the main grain-producing areas, and the regions with less geographical fluctuation. Additionally, agricultural innovations, capital accumulation, and land circulation reinforce the benefits of such construction, whereas labor mobility has a moderating effect. Quantile regression analyses show that the impact of HFC on AEE initially increases and then diminishes, potentially due to inadequate post-management and maintenance. Consequently, the study recommends that the government enhance policy support and supervision for high-standard farmland projects, integrate agricultural technology with capital accumulation, optimize human resource allocation, guide labor mobility, and reform land transfer systems to boost AEE and sustainability.
Spatial and Temporal Change Analysis of Urban Built-Up Area via Nighttime Lighting Data—A Case Study with Yunnan and Guizhou Provinces
Authors: Jing Qian , Marino Armando , Ji Yongjie , Zhao Han , Huang Guoran , Wang Lu
Published: October 2024

As urbanization accelerates, characteristics of urban spatial expansion play a significant role in the future utilization of land resources, the protection of the ecological environment, and the coordinated development of population and land. In this study, Yunnan and Guizhou provinces were selected as the study area, and the 2013–2021 National Polar-Orbiting Partnership’s Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) nighttime light (NTL) data were utilized for spatial and temporal change analysis of urban built-up areas. Firstly, the built-up areas in Yunnan and Guizhou provinces were extracted through ENUI (Enhanced Nighttime Lighting Urban Index) indices, and then the urban expansion speed and urban center of gravity migration were constructed and used to explore and analyze the spatial and temporal change and expansion characteristics of built-up areas in Yunnan and Guizhou provinces. The results showed the following. (1) Due to the complementarity between data types, such as NTL, EVI, NDBI, and NDWI, ENUI has better performance in expressing urban characteristics. (2) Influenced by national and local policies, such as “One Belt, One Road”, transportation infrastructure construction, geographic location, the historical background, and other factors, the urban expansion rate of Yunnan and Guizhou provinces in general showed a continuous advancement from 2013 to 2021, and there were three years in which the expansion rate was positive. (3) The center of gravity migration distance of most cities in Guizhou Province shows a trend of increasing and then decreasing, while the center of gravity migration distance in Yunnan Province shows a trend of continuous decrease in general. From the perspective of migration direction, Guizhou Province has the largest number of migrations to the northeast, while Yunnan Province has the largest number of migrations to the southeast. (4) Influenced by policy, economy, population, geography, and other factors, urban compactness in Yunnan and Guizhou provinces continued to grow from 2013 to 2021. The results of this study can help us better understand urbanization in western China, reveal the urban expansion patterns and spatial characteristics of Yunnan and Guizhou provinces, and provide valuable references for development planning and policymaking in Yunnan and Guizhou provinces.
Short-Term Visual and Refractive Outcomes of Single-Step Transepithelial Photorefractive Keratectomy with Amaris 750S and SmartSurfACE in Myopia and Astigmatism: A 6-Month Follow-Up Study
Authors: Margarit Daiana-Andreea , Stanca Horia Tudor , Mocanu Valeria , Munteanu Mihnea , Marius Suta , Gheorghita Suta
Published: October 2024

Background: Single-step transepithelial photorefractive keratectomy (TPRK) is a modern refractive surgery technique that offers a no-touch approach for correcting myopia and astigmatism. This study aims to evaluate the short-term visual and refractive outcomes of TPRK in patients with myopia and astigmatism over a 6-month follow-up period. Methods: This retrospective cohort study included patients who underwent single-step TPRK using the Amaris 750S laser platform with SmartSurfACE and SmartPulse® technologies, targeting a plano refraction. Procedures were performed with aspheric, non-wavefront-guided profiles, and outcomes were assessed postoperatively. Results: 96% of eyes achieved 20/20 or better uncorrected distance visual acuity (UDVA), with 98% reaching 20/25 or better, and 100% achieving 20/32 or better. UDVA was the same or better than preoperative corrected distance visual acuity (CDVA) in 96% of eyes, and no eyes lost two or more Snellen lines. Refractive outcomes showed strong precision, with 93% of eyes within ±1.00 D of the target. Astigmatism correction was accurate, with 100% of eyes having ≤1.00 D of astigmatism, and 80% achieving a precise astigmatism angle of error between −5° and 5°. Conclusion: Single-step TPRK with SmartSurfACE and SmartPulse® technologies provides highly effective and predictable visual and refractive outcomes for myopia and astigmatism. The procedure consistently delivers precise corrections with minimal complications, making it a reliable option for refractive surgery.
Global Comparison of COVID-19 Vaccination Rates among Psoriasis Patients
Authors: Korouri Edwin , Jeong Charlotte , Peterson Hannah , Valenzuela Fernando , Romiti Ricardo , Didaskalu Johannes A. , Egeberg Alexander , Oon Hazel H. , Maul Lara Valeska , Kingston Paige , Lee Kathryn , Huang Margaret Y. , Yee Danielle , Artiga Kevin , Aguero Rosario , Maul Julia-Tatjana , Armstrong April W.
Published: October 2024

(1) Background: The purpose of this study is to compare the rate of COVID-19 vaccination among psoriasis patients internationally and to correlate it with their treatment regimens. (2) Methods: We conducted a cross-sectional study from January 2021 to October 2022 among adults in the United States (US), Chile, China, Switzerland, and Singapore using the Global Healthcare Study on Psoriasis survey. (3) Results: A total of 310 psoriasis patients in the US (98), Chile (32), China (80), Switzerland (39), and Singapore (61) were surveyed. Of these, 248 patients (80.0%) were vaccinated at least once for COVID-19 (Chile: 100%, Singapore: 100%, US: 93.9%, Switzerland: 69.2%, China: 45.0%). Compared with other countries, patients in China were 89% less likely to report at least one COVID-19 vaccination (1 − 0.11 = 0.89; OR 0.11; 95% CI: 0.03–0.48), and patients in Switzerland were 80% less likely (1 − 0.20 = 0.80; OR 0.20; 95% CI: 0.05–0.79). Compared with patients on biologics, patients on topicals were 10.9 (95% CI: 2.1–56.6) times more likely to report at least one COVID-19 vaccination, and patients on oral systemics were 7.2 times more likely (95% CI: 1.6–31.6). (4) Conclusions: Country of residence and treatment regimen are associated with different COVID-19 vaccination rates in psoriasis patients.
A Natural Approach to the Prevention and Treatment of Gingivitis and Periodontitis: A Review of Pomegranate’s Bioactive Properties
Authors: Potra Cicalău Georgiana Ioana , Vicaș Laura Grațiela , Ciavoi Gabriela , Ghitea Timea Claudia , Csaba Nagy , Cristea Roxana Alexandra , Miere (Groza) Florina , Ganea Mariana
Published: October 2024

(1) Background: This systematic review explores the bioactive properties of Punica granatum (pomegranate) and its potential applications in the prevention and treatment of gingivitis, periodontitis, and other oral diseases. (2) Methods: A comprehensive literature search was conducted using PubMed and Google Scholar, focusing on pomegranate and oral diseases. Inclusion criteria included studies evaluating the effects of pomegranate on oral health, while exclusion criteria eliminated non-peer-reviewed and non-English articles. This review aims to assess the efficacy of pomegranate extracts as a natural alternative to synthetic pharmaceuticals in oral health care. A structured search strategy included key terms such as “pomegranate”, “oral health”, “gingivitis”, and “periodontitis”. A total of 125 relevant references were reviewed to identify the most pertinent findings. (3) Results: The results indicate that pomegranate extracts have demonstrated efficacy in reducing plaque, inhibiting harmful oral microorganisms, and promoting overall oral health. Furthermore, clinical studies highlight the potential of pomegranate-based products, such as mouthwashes and gels, as viable alternatives to conventional pharmaceuticals, particularly in resource-limited settings. However, the review also notes the need for further research, particularly in the form of clinical trials, to establish optimal formulations and long-term safety. (4) Conclusions: Pomegranate presents a promising, natural solution for preventing and treating gingivitis and periodontitis. Further studies should focus on long-term effects and clinical efficacy.
The Effectiveness of High Intensity Laser in Improving Motor Deficits in Patients with Lumbar Disc Herniation
Authors: Tache-Codreanu Diana-Lidia , Trăistaru Magdalena Rodica
Published: October 2024

Background: High-Intensity Laser (HIL) therapy, known for its biostimulatory effects on nerve cell growth and repair, shows promise for improving motor deficits caused by morphopathological changes. This research study aimed to comprehensively assess muscle strength changes through muscle testing, complemented by functional tests evaluating factors contributing to disability in patients with Lumbar Disc Herniation (LDH) and associated motor impairment, following a complex rehabilitation protocol incorporating HIL therapy. Methods: A total of 133 individuals with LDH and motor deficits were divided into two groups. Group 1 (n = 66) received HIL therapy followed by standard rehabilitation, while Group 2 (n = 67) underwent only the standard rehabilitation program. Functional parameters, including muscle strength, the ability to walk on tiptoes or heels, and self-assessed fall risk, were monitored. Results: Both groups showed statistically significant improvements in all monitored parameters. A comparative analysis revealed a significant result for the HIL therapy regimen across all indicators. Conclusions: The group undergoing a rehabilitation program with integrated HIL therapy displayed significantly greater improvement in motor deficits, affirming the positive impact of HIL therapy on functional parameters among LDH patients.
Optimizing Continuous Renal Replacement Therapy with Regional Citrate Anticoagulation: Insights from the ORCA Trial—A Retrospective Study on 10 Years of Practice
Authors: Jacobs Rita , Verbrugghe Walter , Bouziotis Jason , Baar Ingrid , Dams Karolien , De Weerdt Annick , Jorens Philippe G.
Published: October 2024

(1) Background: Citrate is preferred in continuous renal replacement therapy (CRRT) for critically ill patients because it prolongs filter life and reduces bleeding risks compared to unfractionated heparin (UFH). However, regional citrate anticoagulation (RCA) can lead to acid–base disturbances, citrate accumulation, and overload. This study compares the safety and efficacy of citrate-based CRRT with UFH and no anticoagulation (NA) in acute kidney injury (AKI) patients. (2) Methods: A retrospective analysis was conducted on adult patients (≥18 years) who underwent CRRT from July 2010 to June 2021 in an intensive care unit. (3) Results: Among 829 AKI patients on CRRT: 552 received RCA, 232 UFH, and 45 NA. The RCA group had a longer filter lifespan compared to UFH and NA (56 h [IQR, 24–110] vs. 36.0 h [IQR, 17–63.5] vs. 22 h [IQR, 12–48]; all Padj < 0.001). Bleeding complications were fewer in the RCA group than in the UFH group (median 3 units [IQR, 2–7 units] vs. median 5 units [IQR, 2–12 units]; Padj < 0.001) and fewer in the NA group than in the UFH group (median 3 units [IQR, 1–5 units] vs. 5 units [IQR, 2–12 units]; Padj = 0.03). Metabolic alkalosis was more common in the RCA group (32.5%) compared to the UFH (16.2%) and NA (13.5%) groups, while metabolic acidosis persisted more in the UFH group and NA group (29.1% and 34.6%) by the end of therapy vs. the citrate group (16.8%). ICU mortality was lower in the RCA group (52.7%) compared to the UFH group (63.4%; Padj = 0.02) and NA group (77.8%; Padj = 0.003). (4) Conclusions: Citrate anticoagulation outperforms heparin-based and no anticoagulation in filter patency, potentially leading to better outcomes through improved therapy effectiveness and reduced transfusion needs. However, careful monitoring is crucial to limit potential complications attributable to its use.
Current Advancements in Drone Technology for Medical Sample Transportation
Authors: Stierlin Noel , Risch Martin , Risch Lorenz
Published: October 2024

Background: The integration of drone technology into healthcare logistics presents a significant opportunity to enhance the speed, reliability, and efficiency of medical sample transportation. Methods: This paper provides a narrative review of current advancements in drone technology, focusing on its application in the rapid and secure delivery of medical samples, particularly in urban and remote regions where traditional transportation methods often face challenges. Drawing from recent studies and case reports, the review highlights the role of technologies such as artificial intelligence (AI)-driven navigation systems, real-time monitoring, and secure payload management in mitigating logistical barriers like traffic congestion and geographical isolation. Results: Based on findings from various case studies, the review demonstrates how drones can significantly reduce transportation time and costs, while improving accessibility to healthcare services in underserved areas. Conclusions: This paper concludes that, while challenges such as regulatory hurdles and privacy concerns remain, ongoing technological advancements and the development of supportive regulatory frameworks have the potential to revolutionize medical logistics, ultimately improving patient outcomes and healthcare delivery.
Mixed Friction in Fully Lubricated Elastohydrodynamic Contacts—Theory or Reality
Authors: Bartel Dirk
Published: October 2024

Mixed friction in liquid-lubricated tribosystems is characterized by the simultaneous presence of liquid and solid friction. Liquid friction results from the shearing of the lubricant, and solid friction from deformation and adhesion. Elastic hysteresis and plastic deformation of the solids cause energy losses during deformation and the separation of molecular bonds between the solids causes energy losses during adhesion. The classic conception of mixed friction presupposes direct contact between rough solids for solid friction to exist. However, if hysteresis losses are fully accepted as a cause for solid friction, every fully lubricated elastohydrodynamic contact would ultimately be a mixed friction contact since the elastic deformations of the solids also cause a loss of energy induced by hysteresis. Thus, the classic conception of mixed friction should be expanded since mixed friction can occur even when solids do not have any direct contact.
Investigation of Tribological Properties of Inconel 601 under Environmentally Friendly MQL and Nano-Fluid MQL with Pack Boronizing
Authors: Uslu Gonca , Korkmaz Mehmet Erdi , Elkilani Rajab Hussein Rajab , Gupta Munish Kumar , Vashishtha Govind
Published: October 2024

Friction and high temperatures greatly affect the hardness and processing efficiency of superalloys. Therefore, it is important to provide a coating on their surfaces with a hard layer. In this study, pack boronizing was applied on Inconel 601 to improve its microstructure and tribological properties. In this regard, tribological tests were performed under MQL, nano-MQL1 (MQL + CuO), and nano-MQL2 (MQL + TiO2) environments. The research results showed that the lowest wear depth, friction force, coefficient of friction (CoF), and volume loss values were obtained in pack-boronized Inconel 601 in a nano-MQL2 environment. In the nano-MQL2 environment, the wear depth decreased by 17.81% (from 57.922 µm to 47.605 µm) with package-boronized Inconel 601 compared to as-received Inconel 601 at a 45 N load. Pack-boronized Inconel 601 experienced an average reduction of 30.23%, 41.60%, and 52.32% in friction force when switching from dry to MQL, nano-MQL1, and nano-MQL2 environments, respectively. It was also observed that the coefficient of friction (CoF) and volume loss values decreased with pack boronizing in an MQL/nano-MQL environment. In a nano-MQL2 environment at 15 N load, volume losses for as-received and boron-coated Inconel 601 were determined as 0.288 mm3 and 0.249 mm3, respectively (13.54% decrease). The findings of this study demonstrate that pack boronizing and MQL and nano-MQL techniques enhance the tribological characteristics of Inconel 601 alloys.
Constitutive Damage Model for Rubber Fiber-Reinforced Expansive Soil under Freeze–Thaw Cycles
Authors: Wang Rongchang , Yang Zhongnian , Ling Xianzhang , Shi Wei , Sun Zhenxing , Qin Xipeng
Published: October 2024

To elucidate the degradation mechanism of expansive soil–rubber fiber (ESR) under freeze–thaw cycles, freeze–thaw cycle tests and consolidated undrained tests were conducted on the saturated ESR. The study quantified the elastic modulus and damage variables of ESR under different numbers of freeze–thaw cycles and confining pressure, and proposed a damage constitutive model for ESR. The primary findings indicate that: (1) The effective stress paths of ESR exhibit similarity across different numbers of freeze–thaw cycles, the critical stress ratio slightly decreased by 8.8%, while the normalized elastic modulus experienced a significant reduction, dropping to 42.1%. (2) When considering the damage threshold, the shear process of ESR can be divided into three stages: weak damage, damage development, and failure. As strain increases, the microdefects of ESR gradually develop, penetrating macroscopic cracks and converging to form the main rupture surface. Eventually, the damage value reaches 1. (3) Due to the effect of freeze–thaw cycles, initial damage exists for ESR, which is positively correlated with the number of freeze–thaw cycles. The rubber fibers act as tensile elements, and the ESR damage evolution curves intersect one after another, showing obvious plastic characteristics in the late stage of shear. (4) Confining pressure plays a role in limiting the development of ESR microcracks. The damage deterioration of ESR decreases with an increase in confining pressure, leading to an increase in ESR strength. (5) Through a comparison of the test curve and the theoretical curve, this study validates the rationality of the damage constitutive model of ESR under established freeze–thaw cycles. Furthermore, it accurately describes the nonlinear impact of freeze–thaw cycles and confining pressure on the ESR total damage.
High-Temperature Creep Resistance of FeAlOY ODS Ferritic Alloy
Authors: Dymáček Petr , Jarý Milan , Bártková Denisa , Luptáková Natália , Gamanov Štepán , Bořil Petr , Georgiev Vjaceslav , Svoboda Jiří
Published: October 2024

A significant effort in optimizing the chemical composition and powder metallurgical processing led to preparing new-generation ferritic coarse-grained ODS alloys with a high nano-oxide content. The optimization was aimed at high-temperature creep and oxidation resistance at temperatures in the range of 1100–1300 °C. An FeAlOY alloy, with the chemical composition Fe–10Al–4Cr–4Y2O3 (wt. %), seems as the most promising one. The consolidation of the alloy is preferably conducted by hot rolling in several steps, followed by static recrystallization for 1 h at 1200 °C, which provides a stable coarse-grain microstructure with homogeneous dispersion of nano-oxides. This represents the most cost-effective way of production. Another method of consolidation tested was hot rotary swaging, which also gave promising results. The compression creep testing of the alloy at 1100, 1200, and 1300 °C shows excellent creep performance, which is confirmed by the tensile creep tests at 1100 °C as well. The potential in such a temperature range is the target for possible applications of the FeAlOY for the pull rods of high-temperature testing machines, gas turbine blades, or furnace fan vanes. The key effort now focuses on expanding the production from laboratory samples to larger industrial pieces.
The Microbiologically Influenced Corrosion and Protection of Pipelines: A Detailed Review
Authors: Lv Xueqing , Wang Can , Liu Jia , Sand Wolfgang , Nabuk Etim Ini-Ibehe , Zhang Yimeng , Xu Ailing , Duan Jizhou , Zhang Ruiyong
Published: October 2024

Microbial corrosion is the deterioration of materials associated with microorganisms in environments, especially in oil- and gas-dominated sectors. It has been widely reported to cause great losses to industrial facilities such as drainage systems, sewage structures, food-processing equipment, and oil and gas facilities. Generally, bacteria, viruses, and other microorganisms are the most important microorganisms associated with microbial corrosion. The destructive nature of these microorganisms differs based on the kind of bacteria involved in the corrosion mechanism. Amongst the microorganisms related to microbial corrosion, sulfate-reducing bacteria (SRB) is reported to be the most common harmful bacteria. The detailed mechanistic explanations relating to the corrosion of pipelines by sulfate-reducing bacteria are discussed. The mechanism of microbial corrosion in pipelines showing the formation of pitting corrosion and cathodic depolarization is also reported. The current review provides theoretical information for the control and protection of pipelines caused by microbial corrosion and how new eco-friendly protection methods could be explored.
Automatic High-Resolution Operational Modal Identification of Thin-Walled Structures Supported by High-Frequency Optical Dynamic Measurements
Authors: Deng Tongfa , Wang Yuexin , Huang Jinwen , Cao Maosen , Sumarac Dragoslav
Published: October 2024

High-frequency optical dynamic measurement can realize multiple measurement points covering the whole surface of the thin-walled structure, which is very useful for obtaining high-resolution spatial information for damage localization. However, the noise and low calculation efficiency seriously hinder its application to real-time, online structural health monitoring. To this end, this paper proposes a novel high-resolution frequency domain decomposition (HRFDD) modal identification method, combining an optical system with an accelerometer for measuring high-accuracy vibration response and introducing a clustering algorithm for automated identification to improve efficiency. The experiments on the cantilever aluminum plate were carried out to evaluate the effectiveness of the proposed approach. Natural frequency and damping ratios were obtained by the least-squares complex frequency domain (LSCF) method to process the acceleration responses; the high-resolution mode shapes were acquired by the singular value decomposition (SVD) processing of global displacement data collected by high-speed cameras. Finally, the complete set of the first nine order modal parameters for the plate within the frequency range of 0 to 500 Hz has been determined, which is closely consistent with the results obtained from both experimental modal analysis and finite element analysis; the modal parameters could be automatically picked up by the DBSCAN algorithm. It provides an effective method for applying optical dynamic technology to real-time, online structural health monitoring, especially for obtaining high-resolution mode shapes.
Testing Mortars for 3D Printing: Correlation with Rheological Behavior
Authors: Bao Ta Minh Phuong , Yeakleang Muy , Abdelouhab Sandra , Courard Luc
Published: October 2024

Three-dimensionally printed concrete is a transformative technology that addresses housing shortages due to population growth and enables innovative architectural designs. The objective of this study is to investigate the connection between a conventional test and the rheological properties of 3D-printed concrete. A more precise assessment of material quality based on traditional evaluation techniques is proposed. Standard tests are conducted to evaluate the consistency of 3D-printed concrete materials. Complementarily, a rheometer is employed to accurately measure key rheological properties, thereby establishing a link with empiric testing methodologies. The correlation between the flow table test and rheological coefficients, such as yield stress and viscosity, has been identified as the most effective in basic experiments for evaluating material behavior. This approach allows for a preliminary assessment of printability without the need for additional complex equipment. The study has successfully established a relationship between flow table tests and rheological parameters. However, further research involving a broader range of materials and print-test experiments is essential to enhance the correlation between other conventional testing methods and rheometer results.
Experimental Study on the Strength and Durability of Manufactured Sand HPC in the Dalian Bay Undersea Immersed Tube Tunnel and Its Engineering Application
Authors: Sun Yuefeng , Song Shanshan , Yu Hongfa , Ma Haiyan , Xu Yu , Zu Guojia , Ruan Yang
Published: October 2024

The usage of manufactured sand concrete is widespread in modern engineering, and it is important to study its performance to improve the overall engineering quality. This paper presents an experimental study on the working performance and durability of 12 groups of manufactured sand high-performance concrete (MSHPC) with varying mix ratios, in the context of the construction of the Dalian Bay undersea immersed tube tunnel. The study reveals that the stone powder content significantly affects the physical and mechanical properties, as well as the durability, of manufactured sand concrete. At an approximately 9% stone powder content, the concrete achieves the highest slump and best workability. However, excessive stone powder reduces early crack resistance. Furthermore, an optimal stone powder content (ranging from 5% to 13%) enhances the compressive strength, with the 28-day compressive strength reaching 60 MPa at a 13% stone powder content, while the effect on the splitting tensile strength is negligible. The stone powder content does not significantly impact impermeability and frost resistance, but at 7–9%, the RCM method shows the lowest chloride ion diffusion coefficient. Additionally, a lower water–binder ratio enhances resistance to chloride ion diffusion. High-performance RCM concrete with a 9% stone powder content was used in the construction of the Dalian Bay Cross-Harbor Tunnel, achieving 28-day and 56-day compressive strengths of C45 and C50, respectively, an impermeability grade of P14, a chloride ion diffusion coefficient of 1.9 × 10−12 m2/s, and a frost durability index of 92%, meeting the project’s 100-year lifespan design requirements.
Three-Dimensional Micromechanical Modeling of Martensite Particle Size Effects on the Deformation Behavior of Dual-Phase Steels
Authors: Cavusoglu Onur , Toros Serkan
Published: October 2024

The objective of this study was to examine the influence of martensite particle size on the formation of stress and strain in microstructures of dual-phase steels. In order to achieve this objective, the 3D representative volume element (RVE) method was utilized. Particle size distributions were obtained from the microstructures of DP600 and DP1000 dual-phase steels as they actually exist. Virtual dual-phase steel microstructures were generated according to the above distribution and subsequent validation analyses were performed. In the subsequent phase, microstructures of varying martensite particle sizes (1 µm, 1.98 µm, 3 µm for DP600 and 1.15 µm, 2 µm, 3 µm for DP1000) were formed, and the effects of particle size on deformation behavior under tensile loads were determined. The findings indicated that an increase in martensite particle size resulted in a reduction in tensile strength, accompanied by an increase in deformation amount.
Development of a Quality Control System Using Modal Analysis to Evaluate a Multi-Point Projection Welding Process
Authors: Karpiński Maciej , Sokołowski Paweł , Kustroń Paweł , Mikno Zygmunt , Jopek Wojciech , Pikuła Janusz
Published: October 2024

The article presents the results of the development and research regarding the application of modal analysis to the evaluation of a multi-point projection welding process. The quality control system is based on the information provided by modal analysis for the entire welding station after the previously completed welding process. The research is carried out due to the lack of an effective method for assessing the course of the multi-spot projection welding process in the case of a single current circuit passing through many points at the same time. A study of the applicability of modal analysis in investigating the quality of a multipoint joint was conducted for four DIN 928 nuts welded to a steel profile. The aim of the study was to determine the influence of weld defects on the displacement of resonant frequencies. To realize the objective, the dynamic properties of the entire welding station, including the sample in the frequency domain, were investigated. In the first stage of the study, a finite element method was used to perform modal analysis and examine the form of vibrations for the individual natural frequencies of the welding fixture including the sample. Then, quality verification using the dynamic resistance method was performed, which was compared later with the modal approach. The last stage of the study was to conduct modal analysis in the frequency domain to verify the numerical studies.
Effect of Cooling Rate on α Variant Selection and Microstructure Evolution in TB17 Titanium Alloy
Authors: Shang Guoqiang , Gan Xueping , Wang Xinnan , Ge Jinyang , Li Chao , Zhu Zhishou , Zhang Xiaoyong , Zhou Kechao
Published: October 2024

The α variant selection and microstructure evolution in a new metastable β titanium alloy TB17 were studied in depth by DTA, microhardness, XRD, SEM, and EBSD characterization methods. Under the rapid cooling rate conditions (150 °C/min–400 °C/min), only a very small amount of granular αWM (α Widmanstatten precipitates within the grains) precipitated within the grains. The secondary α phase precipitated in the alloy changed from granular to fine needle-like at moderate cooling rates (15 °C/min–20 °C/min). When continuing to slow down the cooling rates (10 °C/min and 1 °C/min), the αGB (α precipitates along the β grain boundaries), αWGB (α Widmanstatten precipitates that developed from β grain boundaries or αGB) and αWM grew rapidly. Moreover, the continuous cooling transformation (CCT) diagram illustrated the effect of cooling rate on the β/α phase transition. EBSD analysis revealed that the variants selection of α near the original β grain boundary is mainly divided into three categories. (i) The double-BOR (Burgers orientation relationship) αWGB colonies within neighboring β grains grow in different directions but have the same crystallographic orientation. (ii) The double-BOR αWGB colonies within neighboring β grains have different growth directions and different crystallographic orientations. (iii) The double-BOR αWGB colonies within the same grain have the same growth direction, but different crystallographic directions. And these double-BOR αWGB colonies correspond to two variants of the given {0001}α//{110}β.
New Eco-Cements Made with Marabou Weed Biomass Ash
Authors: Frías Moisés , Moreno de los Reyes Ana María , Villar-Cociña Ernesto , García Rosario , Vigil de la Villa Raquel , Vasić Milica Vidak
Published: October 2024

Biomass ash is currently attracting the attention of science and industry as an inexhaustible eco-friendly alternative to pozzolans traditionally used in commercial cement manufacture (fly ash, silica fume, natural/calcined pozzolan). This paper explores a new line of research into Marabou weed ash (MA), an alternative to better-known conventional agro-industry waste materials (rice husk, bagasse cane, bamboo, forest waste, etc.) produced in Cuba from an invasive plant harvested as biomass for bioenergy production. The study entailed full characterization of MA using a variety of instrumental techniques, analysis of pozzolanic reactivity in the pozzolan/lime system, and, finally its influence on the physical and mechanical properties of binary pastes and mortars containing 10% and 20% MA replacement content. The results indicate that MA has a very low acid oxide content and a high loss on ignition (30%) and K2O content (6.9%), which produces medium–low pozzolanic activity. Despite an observed increase in the blended mortars’ total and capillary water absorption capacity and electrical resistivity and a loss in mechanical strength approximately equivalent to the replacement percentage, the 10% and 20% MA blended cements meet the regulatory chemical, physical, and mechanical requirements specified. Marabou weed ash is therefore a viable future supplementary cementitious material.
Geophysics-Inspired Nonlinear Stress–Strain Law for Biological Tissues and Its Applications in Compression Optical Coherence Elastography
Authors: Zaitsev Vladimir Y. , Matveev Lev A. , Matveyev Alexander L. , Plekhanov Anton A. , Gubarkova Ekaterina V. , Kiseleva Elena B. , Sovetsky Alexander A.
Published: October 2024

We propose a nonlinear stress–strain law to describe nonlinear elastic properties of biological tissues using an analogy with the derivation of nonlinear constitutive laws for cracked rocks. The derivation of such a constitutive equation has been stimulated by the recently developed experimental technique—quasistatic Compression Optical Coherence Elastography (C-OCE). C-OCE enables obtaining nonlinear stress–strain dependences relating the applied uniaxial compressive stress and the axial component of the resultant strain in the tissue. To adequately describe nonlinear stress–strain dependences obtained with C-OCE for various tissues, the central idea is that, by analogy with geophysics, nonlinear elastic response of tissues is mostly determined by the histologically confirmed presence of interstitial gaps/pores resembling cracks in rocks. For the latter, the nonlinear elastic response is mostly determined by elastic properties of narrow cracks that are highly compliant and can easily be closed by applied compressing stress. The smaller the aspect ratio of such a gap/crack, the smaller the stress required to close it. Upon reaching sufficiently high compressive stress, almost all such gaps become closed, so that with further increase in the compressive stress, the elastic response of the tissue becomes nearly linear and is determined by the Young’s modulus of the host tissue. The form of such a nonlinear dependence is determined by the distribution of the cracks/gaps over closing pressures; for describing this process, an analogy with geophysics is also used. After presenting the derivation of the proposed nonlinear law, we demonstrate that it enables surprisingly good fitting of experimental stress–strain curves obtained with C-OCE for a broad range of various tissues. Unlike empirical fitting, each of the fitting parameters in the proposed law has a clear physical meaning. The linear and nonlinear elastic parameters extracted using this law have already demonstrated high diagnostic value, e.g., for differentiating various types of cancerous and noncancerous tissues.
The Corrosion Fatigue Behavior and Mechanism of AerMet 100 Steel in 3.5% NaCl at Room Temperature
Authors: Tian Donghua , Xu Can , Wang Hongli , Wu Chengchuan , Lu Yonghao
Published: October 2024

AerMet 100 steel is a new type of double-hardened high-strength steel, which is often used as landing gear material in amphibious aircraft. In the present paper, the corrosion fatigue behavior and mechanism of AerMet 100 high-strength steel in a 3.5% NaCl solution was studied by stress-controlled fatigue tests and a series of subsequent characterizations of the fracture surface, microstructure, and cracks. The results indicated that the fatigue life of AerMet 100 high-strength steel decreased with a decrease in the stress level in a 3.5% NaCl solution, satisfying the relationship lgN = −2.69 × 10−3 σ + 6.49. The corrosion fatigue crack usually initiated from the corrosion pit and propagated across the martensitic flat noodles. Meanwhile, the corrosion fatigue crack tip was filled with Cr2O3, Fe2O3, and amorphous material; it propagated in the transgranular mode by a slip dissolution mechanism. This study provides some engineering significant for the fatigue performance of AerMet 100 steel in a 3.5% NaCl solution.
Economic Growth Model with Fertility Incentives: A Theoretical Analysis Framework and Policy Simulation for China
Authors: He Lei , Wang Qin
Published: October 2024

This study presents an overlapping generation model to examine the impact of fertility incentive policies on economic growth in China, incorporating endogenous fertility, education, and technological advancement by integrating unified growth theory with an R&D-based growth model. We analyze the impact of fertility incentive policies on economic growth by evaluating maternity insurance and public education. The results show that increasing the actual contribution rate of maternity insurance, maternity benefits, and public education expenditures can boost China’s fertility rate; nevertheless, extending maternity leave would not incentivize an increase in the fertility rate. The impact of fertility incentives on economic growth is ambiguous, depending upon the extent to which increased fertility dilutes aggregate human capital via technical advancement. If the dilution effect is weak, the sign will turn positive, and vice versa. The simulation analysis of the benchmark model indicates that the fertility incentive policy, which encompasses increasing the actual contribution rate of maternity insurance, maternity benefits, and public education expenditure, can foster economic growth in China by enhancing the fertility rate in the long term.
Multiscale Change Point Detection for Univariate Time Series Data with Missing Value
Authors: Haile Tariku Tesfaye , Tian Fenglin , AlNemer Ghada , Tian Boping
Published: October 2024

This paper studies the autoregressive integrated moving average (ARIMA) state space model combined with Kalman smoothing to impute missing values in a univariate time series before detecting change points. We estimate a scale-dependent time-average variance constant that depends on the length of the data section and is robust to mean shifts under serial dependence. The consistency of the proposed estimator is shown under the assumption allowing heavy tailedness. Integrating the proposed estimator with the moving sum and wild binary segmentation procedures to determine the number and locations of change points is discussed. Furthermore, the performance of the proposed methods is evaluated through extensive simulation studies and applied to the Beijing multi-site air quality dataset to impute missing values and detect mean changes in the data.
New Statistical Residuals for Regression Models in the Exponential Family: Characterization, Simulation, Computation, and Applications
Authors: Ospina Raydonal , Espinheira Patrícia L. , Arias Leilo A. , Xavier Cleber M. , Leiva Víctor , Castro Cecilia
Published: October 2024

Residuals are essential in regression analysis for evaluating model adequacy, validating assumptions, and detecting outliers or influential data. While traditional residuals perform well in linear regression, they face limitations in exponential family models, such as those based on the binomial and Poisson distributions, due to heteroscedasticity and dependence among observations. This article introduces a novel standardized combined residual for linear and nonlinear regression models within the exponential family. By integrating information from both the mean and dispersion sub-models, the new residual provides a unified diagnostic tool that enhances computational efficiency and eliminates the need for projection matrices. Simulation studies and real-world applications demonstrate its advantages in efficiency and interpretability over traditional residuals.
A Morley Type Triangular Finite Element with High Convergence for the Biharmonic Problem
Authors: Bao Yuan , Yang Sibo
Published: October 2024

In this work, we construct a theoretical framework to develop non C0 Morley type nonconforming high-convergence elements for biharmonic problems. For each element domain, P3 should be included in the space of shape functions. Besides the degrees of freedom of Morley elements, we add the integrals and first-order moments of the normal derivatives on edges. The choice of degrees of freedom and shape function space guarantees the possibility of improving the convergence order. As an application, we specifically construct a Morley type element on triangular meshes. Lastly, numerical experiments are carried out to verify the feasibility of the element.
A Martingale Posterior-Based Fault Detection and Estimation Method for Electrical Systems of Industry
Authors: Cheng Chao , Wang Weijun , Di He , Li Xuedong , Lv Haotong , Wan Zhiwei
Published: October 2024

The improvement of information sciences promotes the utilization of data for process monitoring. As the core of modern automation, time-stamped signals are used to estimate the system state and construct the data-driven model. Many recent studies claimed that the effectiveness of data-driven methods relies greatly on data quality. Considering the complexity of the operating environment, process data will inevitably be affected. This poses big challenges to estimating faults from data and delivers feasible strategies for electrical systems of industry. This paper addresses the missing data problem commonly in traction systems by designing a martingale posterior-based data generation method for the state-space model. Then, a data-driven approach is proposed for fault detection and estimation via the subspace identification technique. It is a general scheme using the Bayesian framework, in which the Dirichlet process plays a crucial role. The data-driven method is applied to a pilot-scale traction motor platform. Experimental results show that the method has good estimation performance.
Adaptive Measurement and Parameter Estimation for Low-SNR PRBC-PAM Signal Based on Adjusting Zero Value and Chaotic State Ratio
Authors: Lv Minghui , Yan Xiaopeng , Wang Ke , Hao Xinhong , Dai Jian
Published: October 2024

Accurately estimating the modulation parameters of pseudorandom binary code–pulse amplitude modulation (PRBC–PAM) signals damaged by strong noise poses a significant challenge in emitter identification and countermeasure. Traditionally, weak signal detection methods based on chaos theory can handle situations with low signal-to-noise ratio, but most of them are developed for simple sin/cos waveform and cannot face PRBC–PAM signals commonly used in ultra-low altitude performance equipment. To address the issue, this article proposes a novel adaptive detection and estimation method utilizing the in-depth analysis of the Duffing oscillator’s behaviour and output characteristics. Firstly, the short-time Fourier transform (STFT) is used for chaotic state identification and ternary processing. Then, two novel approaches are proposed, including the adjusting zero value (AZV) method and the chaotic state ratio (CSR) method. The proposed weak signal detection system exhibits unique capability to adaptively modify its internal periodic driving force frequency, thus altering the difference frequency to estimate the signal parameters effectively. Furthermore, the accuracy of the proposed method is substantiated in carrier frequency estimation under varying SNR conditions through extensive experiments, demonstrating that the method maintains high precision in carrier frequency estimation and a low bit error rate in both the pseudorandom sequence and carrier frequency, even at an SNR of −30 dB.
Analysis of Fractional Order-Adaptive Systems Represented by Error Model 1 Using a Fractional-Order Gradient Approach
Authors: Sánchez-Rivero Maibeth , Duarte-Mermoud Manuel A. , Travieso-Torres Juan Carlos , Orchard Marcos E. , Ceballos-Benavides Gustavo
Published: October 2024

In adaptive control, error models use system output error and adaptive laws to update controller parameters for control or identification tasks. Fractional-order calculus, involving non-integer-order derivatives and integrals, is increasingly important for modeling, estimation, and control due to its ability to generalize classical methods and offer improved robustness to disturbances. This paper addresses the gap in the literature where fractional-order gradient methods have not yet been extensively applied in identification and adaptive control schemes. We introduce a fractional-order error model with fractional-order gradient (FOEM1-FG), which integrates fractional gradient operators based on the Caputo fractional derivative. By using theoretical analysis and simulations, we confirm that FOEM1-FG maintains stability and ensures bounded output errors across a variety of input signals. Notably, the fractional gradient’s performance improves as the order, β, increases with β>1, leading to faster convergence. Compared to existing integer-order methods, the proposed approach provides a more flexible and efficient solution in adaptive identification and control schemes. Our results show that FOEM1-FG offers superior stability and convergence characteristics, contributing new insights to the field of fractional calculus in adaptive systems.
Einstein Exponential Operational Laws Based on Fractional Orthotriple Fuzzy Sets and Their Applications in Decision Making Problems
Authors: Qiyas Muhammad , Karabasevic Darjan , Khan Neelam , Maričić Srdjan
Published: October 2024

The fractional orthotriple fuzzy set (FOFS) model is a recently created extension of fuzzy sets (FS) for coping with ambiguity in DM. The purpose of this study is to define new exponential and Einstein exponential operational (EO) laws for fractional orthotriple fuzzy sets and the aggregation procedures that accompany them. We present the operational laws for exponential and Einstein exponential FOFSs which have crisp numbers as base values and fractional orthotriple fuzzy numbers as exponents (weights). The proposed operations’ qualities and characteristics are then explored. Based on the defined operation laws regulations, various new FOFS aggregation operators, named as fractional orthotriple fuzzy weighted exponential averaging (FOFWEA), fractional orthotriple fuzzy ordered weighted exponential averaging (FOFOWEA), fractional orthotriple fuzzy hybrid weighted averaging (FOFHWEA), fractional orthotriple fuzzy Einstein weighted exponential averaging (FOFEWEA), fractional orthotriple fuzzy Einstein ordered weighted exponential averaging (FOFEOWEA), and fractional orthotriple fuzzy Einstein hybrid weighted exponential averaging (FOFEHWEA) operators are presented. A decision-making algorithm based on the newly defined aggregation operators is proposed and applied to a multicriteria group decision-making (MCGDM) problem related to bank security. Finally, we compare our proposed method with other existing methods.