bluuebunny/crossref_metadata_2025 huggingface dataset:
Arthroscopic Management of Pigmented Villonodular Synovitis of the Hip: A Systematic Review
Authors: Giai Via Riccardo , Giachino Matteo , Elzeiny Ahmed , Santarsiero Gianvito , Cipolla Alessandra , Pantè Salvatore , Bosco Francesco , Zoccola Kristijan , Massè Alessandro , Aprato Alessandro
Published: October 2024

Background/Objectives: Pigmented villonodular synovitis (PVNS) is a benign proliferation of synovial tissue that can cause joint damage. The hip, although less commonly affected than the knee, presents a challenging diagnosis and treatment, with magnetic resonance imaging (MRI) as the gold standard for detection. Surgical excision, arthroscopic or open, is the main treatment approach, but there is no consensus on the best strategy for the hip. The aim of this systematic review is to evaluate the clinical outcomes, complications, and revision rates associated with arthroscopic hip surgery for PVNS. Methods: A systematic review was performed following the PRISMA guidelines. Relevant studies were identified by searching four databases: PubMed, Scopus, Embase, and Medline. Selected articles were evaluated according to the criteria of levels of evidence (LoE). For retrospective studies, the Coleman Methodology Score (mCMS) was used. This systematic review was registered with the International Prospective Register of Systematic Reviews. Results: Six studies satisfied the criteria; these involved 77 patients (48% male, 52% female) with a mean age of 26.4 years and a mean follow-up of 54.3 months. MRI and biopsy confirmed the diagnoses, and arthroscopic synovectomy was the primary treatment. Success rates ranged from 80% to 100%, with a recurrence rate of 7.8%, 1.3% requiring revision surgery, and eight (10.4%) patients in three studies reporting conversion to THA. Complications included mild effusions and residual synovitis. All patients who underwent a subsequent total hip arthroplasty were affected by advanced osteoarthritis. Conclusions: Our systematic review reveals that the use of hip arthroscopy in diagnosing and treating PVNS has shown satisfactory results without increasing the risk of recurrence or complications and can return patients to their former activity levels, provided their preoperative osteochondral status is good and there is early management of PVNS of the hip joint.
Frequencies or Absolute Numbers? Cluster Analysis of Frequencies and Absolute Numbers of B-Cell Subsets in Dialysis Patients Who Are Candidates for Kidney Transplantation Reveals Different Profiles
Authors: Fouza Ariadni , Fylaktou Asimina , Tagkouta Anneta , Daoudaki Maria , Vagiotas Lampros , Kasimatis Efstratios , Xochelli Aliki , Nikolaidou Vasilki , Katsanos Georgios , Tsoulfas Georgios , Skoura Lemonia , Papagianni Aikaterini , Antoniadis Nikolaos
Published: October 2024

Background: Detailed characterization of B cells in dialysis patients who are candidates for kidney transplant is still lacking, with little information on how dialysis duration and modality impact B cell subsets. Methods: Cluster analysis of flow cytometry determined the frequencies and absolute numbers of B-cell subsets and divided the cohort of 78 candidates into two distinct clusters, one with shorter and one with longer dialysis duration. Results: The immune profiles of the clusters differed depending on whether frequencies or absolute counts were considered. In long-term dialysis patients, the frequency of total memory, double negative and marginal zone B cells increased, while the frequency of naive and regulatory B cells decreased. This pattern was reversed in short-term dialysis patients, with a decrease in memory and an increase in naive and regulatory populations. The B subset number decreased significantly in long-term dialysis patients, while it increased significantly in short-term dialysis patients. The dialysis modality affected the frequency-based subset immune profiles. Conclusions: It is important to determine whether the evaluation is based on frequencies or absolute numbers. The different distribution of B cell subsets in the clusters, in terms of frequencies and absolute numbers, was influenced by dialysis duration. Modality and age only influenced the frequencies.
Influence of Femoral Stem Geometry on Total Hip Replacement: A Comparison of Clinical Outcomes of a Straight and an Anatomical Uncemented Stem
Authors: Berdini Massimo , Procaccini Roberto , Zanoli Gabriele Franco , Faini Andrea , Verdenelli Aldo , Gigante Antonio
Published: October 2024

Background/Objectives: There are many aspects that may influence clinical outcomes in a total hip arthroplasty (THA). The influence of femoral stem on the clinical outcome of THA is probably underestimated in the literature. Our work aims to analyze how uncemented stem geometry (straight or anatomical) in THA might affect outcomes in clinical and radiographic terms. Methods: Over a period of 36 months, in a prospective-observational manner, we collected the results of THA secondary to osteoarthritis (OA) that met the inclusion criteria with the only variable being the straight or anatomical stem design in a single manufacturer. A total of 84 patients were selected and divided into two groups: group A, treated with straight stem (44 patients), and group B, treated with anatomical stem (40 patients). The assessment clinical tools were Harris Hip Score (HHS), Visual Analogue Scale (VAS), and Short Form Health Survey-36 (SF-36). Follow-up controls were at 6 months (T0), 12 months (T1), 24 months (T2), and 36 months (T3). Results: No statistically significant differences emerged between the two groups under analysis with VAS, SF-36, and HHS. At follow-up controls, eight patients (group A) and four patients (group B) showed anterior thigh pain. At T1, there were radiographic signs of aseptic loosening in two cases (group A) and one case (group B). In group A there were two cases of iatrogenic fracture, two cases of dislocation, one case of infection, and two cases of heterotopic ossification. Conclusions: The anatomical stem compared to the straight stem showed lower complication rates outcomes; the anatomical uncemented stem could be considered as a preferred first choice in THA compared to the straight stem.
Implementation of Medical Hospitalist Care at a Korean Tertiary Hospital: A Retrospective Cross-Sectional Study
Authors: Lee Han Sung , Park Seung Kyo , Moon Sung Woo
Published: October 2024

Background/Objectives: In March 2018, a tertiary teaching hospital launched a medical hospitalist team. This study presents the clinical characteristics and outcomes of medical hospitalist care and reveals the relationship between them. Methods: This study included 4003 patients first admitted to the hospitalist team via emergency room and then discharged from the hospitalist team between March 2018 and November 2022. The patients were admitted either to the teaching admitter hospitalist team or the hospitalist-led acute medical unit (AMU). Afterward, the patients were either discharged, if possible, within a few days or transferred to ward hospitalists if assigned wards for hospitalist care were available. Results: The patients’ mean Charlson Comorbidity Index score was 3.5 and the mean National Early Warning Score was 3.4. Of the admissions, 44.2% of the patients were admitted to the AMU, and 26.8% received an early consultation with a subspecialist. Each hospitalist managed 12.8 patients per month on average. The patients’ mean LOS was 14.52 days, 10.5% of patients died during hospitalization, and 13.0% of patients had unscheduled readmission within 1 month. The patients’ mean total cost per hospital stay was 572,836 won per day. Admission to the AMU was associated with a lower total cost per hospital stay, but the relationships with mortality, readmission, and LOS were not significant. Conclusions: The study reports on the outcomes of implementing a medical hospitalist care system that combines short-term admission wards with integrated care models to manage complex cases. These findings provide insights into optimizing hospitalist systems for improved patient outcomes.
Relationship Between Training Frequency and Training Session Duration on Vitality in Recreational Runners: A Cross-Sectional Study
Authors: Varela-Sanz Adrián , Mecías-Calvo Marcos , Borrajo Erika , Muñoz-Pérez Iker
Published: October 2024

Background: Running can improve health status from a biopsychosocial perspective. However, isolation strategies, like the COVID-19 pandemic-induced lockdown, produce deleterious effects on both health status and sport performance. The aim of our study was to investigate recreational runners’ sporting habits, subjective vitality (SV), and well-being after the COVID-19 pandemic-induced lockdown. Methods: After data filtration, 5542 recreational runners (74.5% men and 25.5% women, >18 years) were selected for further analyses. The participants answered preliminary questions regarding sporting habits and completed the validated Spanish version of the Subjective Vitality as a Dynamic Reflection of Well-Being questionnaire for assessing their SV after lockdown. Results: Subjective vitality scores did not differ between men and women, nor between age groups (p = 0.41 and p = 0.11, respectively). Subjective vitality was greater with weekly training frequency up to 5 days/week, where this enhancement plateaued, while average training session duration was positively related to SV, stabilizing at 91–120 min/session (p < 0.001 for both). Conclusions: There is a dose–response relationship between both weekly training frequency and training session duration, and mental health benefits in recreational runners. Further longitudinal studies are needed in order to determine the optimal dose–response relationship for simultaneously enhancing mental health outcomes and running performance in recreational runners, especially regarding weekly training frequency, training session duration, and exercise intensity.
Potential Effects of Soccer Ball Characteristics on Ball-to-Head Contact: A Systematic Review
Authors: Oliva-Lozano José M. , Gómez-Carmona Carlos D. , Muyor José M. , Chiampas George T. , Pauwels Barry , Cost Rick
Published: October 2024

Background: The aim of this study was to systematically review research on the effect of soccer ball characteristics on ball-to-head contact. Methods: This systematic review was conducted using electronic databases, which included PubMed, Cochrane, and Web of Science. The search strategy combined keywords related to soccer, the ball and its characteristics, heading, and kinematics variables. Studies analyzing the impact of soccer ball characteristics on heading biomechanics were included. The review included studies using mathematical models, simulations, and human subjects. Results: A total of nine studies were included, highlighting the lack of evidence on this topic. The following ball characteristics were investigated: inflation pressure (n = 7), mass (n = 4), structure/material properties (n = 3), size/diameter (n = 3), and stiffness (n = 3). Most studies used non-human subjects, such as mathematical, simulated, or head-form models. Key findings were as follows: (a) reducing inflation pressure may decrease impact magnitude; (b) ball size may not directly relate to impact magnitude, but one study found that a smaller size resulted in a shorter impact time; (c) lower impact observed with decreasing ball mass; (d) lowering stiffness showed a tendency to lower impact; (e) two studies on water absorption found that wet balls were heavier and had greater impact forces than dry balls; and (f) ball structure and cover material directly influenced impulsive forces. Conclusions: Modifying soccer ball characteristics may reduce heading forces, but the available research has limitations. More controlled studies are needed to determine optimal ball properties for mitigating injury risk during soccer heading. Standardized testing methods can further clarify the biomechanics of heading, supporting ongoing innovations to enhance player experience.
Finite Element Simulation of Ti-6Al-4V Alloy Machining with a Grain-Size-Dependent Constitutive Model Considering the Ploughing Effect Under MQL and Cryogenic Conditions
Authors: Chen Guang , Wu Zhuoyang , Caudill James , Jawahir I.
Published: October 2024

The finite element modeling method has been widely applied in the modeling of the cutting process to characterize the instantaneous and microscale deformation mechanism that was difficult to obtain using physical experiments. The lubrication and cooling conditions, such as minimum quantity lubrication and cryogenic liquid nitrogen, affect the thermo-mechanical behaviors and machined surface integrity in the cutting process. In this work, a grain-size-dependent constitutive model was used to model orthogonal cutting for Ti-6Al-4V alloy with MQL and LN2 conditions. The cutting forces and chip morphologies that were measured in the cutting experiments of Ti-6Al-4V alloy were used to validate the simulated forces. The relative errors between the measured and simulated principal forces were less than 8%, while the relative errors of thrust forces were less than 19%. The predicted chip morphologies and surface grain refinement agreed well with the experimental results under the conditions with different uncut chip thicknesses and edge radii. Additionally, the relationship between the plastic displacement and grain refinement, as well as the microhardness and residual stresses under MQL and cryogenic conditions, were discussed. This work provides an effective modeling method for the orthogonal cutting of Ti-6Al-4V alloy to understand the mechanism of the plastic deformation and machined surface integrity under the MQL and LN2 conditions.
Advancing Marine Surveillance: A Hybrid Approach of Physics Infused Neural Network for Enhanced Vessel Tracking Using Automatic Identification System Data
Authors: Haque Tasmiah , Syed Md Asif Bin , Das Srinjoy , Ahmed Imtiaz
Published: October 2024

In the domain of maritime surveillance, the continuous tracking and monitoring of vessels are imperative for the early detection of potential threats. The Automatic Identification System (AIS) database, which collects vessel movement data over time, including timestamps and other motion details, plays a crucial role in real-time maritime monitoring. However, it frequently exhibits irregular intervals of data collection and intricate, intersecting trajectories, underscoring the importance of analyzing long-term temporal patterns for effective vessel tracking. While Kalman Filters and other physics-based models have been employed to tackle these issues, their effectiveness is limited by their inability to capture long-term dependence and non-linearity in the historical data. This paper introduces a novel approach that leverages Long Short-Term Memory (LSTM), a type of recurrent neural network, renowned for its proficiency in recognizing patterns over extended periods. Recognizing the strengths and limitations of the LSTM model, we propose a hybrid machine-learning algorithm that integrates LSTM with a physics-based model. This combination harnesses the physical laws governing vessel movements alongside data driven pattern mining, thereby enhancing the predictive accuracy of vessel locations. To assess the performance of standalone and hybrid models, various scenarios with different levels of complexity are generated. Furthermore, to simulate real-world data loss conditions often encountered in maritime tracking, temporal data gaps are randomly introduced into the scenarios. The competing approaches are then evaluated using both with time gap and without time gap conditions. Our results show that, although the LSTM model performs better than the physics-based model, the hybrid model consistently outperforms both standalone models across all scenarios. Furthermore, while data gaps negatively impact the accuracy of all models, the performance reduction is minimal for the physics-infused model. In summary, this study not only demonstrates the potential of combining data-driven and physics-based approaches but also sets a new benchmark for maritime vessel tracking.
CFD Applications in Ship and Offshore Hydrodynamics
Authors: Degiuli Nastia , Martić Ivana
Published: October 2024

Computational Fluid Dynamics (CFD) is an emerging field that is rapidly gaining popularity across various industries, including shipbuilding and offshore industry, primarily due to the continuous advancements in computational power [...]
Investigation on Dynamic Behaviors of Ship Propulsion Shafting with Misalignment Based on Stochastic Uncertainty Models
Authors: Xing Pengfei , Zhao Feng , He Xiaoliang , Li Guobin
Published: October 2024

To investigate the effect of stochastic uncertainty on the dynamic behaviors of ship propulsion shafting with misalignment, a stochastic uncertainty model of ship shafting is established based on nonparametric theory and stochastic excitation. Numerical simulation and experimental verification of the dynamic behaviors are carried out using a ship shafting test bench. The results indicate that stochastic uncertainty has a significant effect on the dynamic behaviors of shafting with misalignment. With an increase in stochastic uncertainty, the fractional frequency appears in the spectrum, and the axis trajectory becomes more complex and gradually deviates from the center orbit. Therefore, to ensure the safe navigation of ships, it is necessary to consider the stochastic uncertainty in dynamic research on the misalignment of shafting.
Optimizing Multivariate Time Series Forecasting with Data Augmentation
Authors: Aria Seyed Sina , Iranmanesh Seyed Hossein , Hassani Hossein
Published: October 2024

The convergence of data mining and deep learning has become an invaluable tool for gaining insights into evolving events and trends. However, a persistent challenge in utilizing these techniques for forecasting lies in the limited access to comprehensive, error-free data. This challenge is particularly pronounced in financial time series datasets, which are known for their volatility. To address this issue, a novel approach to data augmentation has been introduced, specifically tailored for financial time series forecasting. This approach leverages the power of Generative Adversarial Networks to generate synthetic data that replicate the distribution of authentic data. By integrating synthetic data with real data, the proposed approach significantly improves forecasting accuracy. Tests with real datasets have proven that this method offers a marked improvement over models that rely only on real data.
Business and Customer-Based Chatbot Activities: The Role of Customer Satisfaction in Online Purchase Intention and Intention to Reuse Chatbots
Authors: Akdemir Doğan Mert , Bulut Zeki Atıl
Published: October 2024

In the online shopping context, brands aim to achieve a high level of profit by providing better customer satisfaction by using various artificial intelligence tools. They try creating a satisfactory customer experience by creating a system that provides never-ending customer support by using dialog-based chatbots, especially in the field of customer service. However, there is a lack of research investigating the impact of business and customer-based chatbot activities together on online purchase intention and the intention to reuse chatbots. This research considers the use of chatbots as a marketing tool from both customer and business perspectives and aims to determine the factors that affect the customers’ intention to purchase online and reuse chatbots. Accordingly, the impact on customer satisfaction with chatbot usage, which is based on chatbots’ communication quality and customers’ motivations to use chatbots, on online purchase intention and intention to reuse chatbots was examined. Through an online questionnaire with two hundred and ten participants, employing structural equation modeling, we revealed that customer satisfaction with chatbot usage has a greater impact on the intention to reuse chatbots than on online purchase intentions. In addition, chatbot communication quality has a greater impact on customer satisfaction with chatbot usage than customers’ motivation to use chatbots. To solidify these findings, confirmatory factor analysis, along with reliability and validity assessments, were implemented within the analytical framework to provide robust support for the study’s hypotheses. These findings not only provide empirical evidence and implications for companies in online shopping but also extend the understanding of AI tools in marketing, highlighting their subtle impact on consumer decision-making in the dynamic digital marketplace.
Temperate Soils Exposed to Drought—Key Processes, Impacts, Indicators, and Unknowns
Authors: Reinsch Sabine , Robinson David A. , van Soest Maud A. J. , Keith Aidan M. , Parry Simon , Tye Andrew M.
Published: October 2024

The summer drought in the United Kingdom (UK) in 2022 produced significant speculation concerning how its termination may impact and interact with the soil resource. Whilst knowledge regarding soils and droughts exists in the scientific literature, a coherent understanding of the wider range of impacts on soil properties and functions has not been compiled for temperate soils. Here, we draw together knowledge from studies in the UK and other temperate countries to understand how soils respond to drought, and importantly what and where our knowledge gaps are. First, we define the different types of droughts and their frequency in the UK and provide a brief overview on the likely societal impacts that droughts place on the soil and related ecosystems. Our focus is on ‘agricultural and ecosystem drought’, as this is when soils experience dry periods affecting crops and ecosystem function, followed by rewetting. The behaviour of moisture in soils and the key processes that contribute to its storage and transport are examined. The principal changes in the physical, chemical, and biological properties of soils resulting from drought, and rewetting (i.e., drought termination) are discussed and their extensive interactions are demonstrated. Processes that are involved in the rewetting of soils are explored for soil and catchment-scale soil responses. Lastly, soils’ recovery after drought is considered, knowledge gaps are identified, and areas to improve understanding are highlighted.
Long-Term Settlement Dynamics in Ancient Macedonia: A New Multi-Disciplinary Survey from Grevena (NW Greece)
Authors: Apostolou Giannis , Venieri Konstantina , Mayoral Alfredo , Dimaki Sofia , Garcia-Molsosa Arnau , Georgiadis Mercourios , Orengo Hector A.
Published: October 2024

This paper discusses the evolution of human settlement in ancient Macedonia from the Neolithic to the Late Roman periods, based on the results of a new multi-disciplinary and multi-scale archaeological survey in northern Grevena (NW Greece). Building upon an unpublished (legacy) survey, we developed a GIS-structured workflow that integrates site-revisiting and surveying strategies (material collection and test pits) with multi-temporal remote-sensing analyses, offering analytical information about site distribution, characterisation, dating, and taphonomy. Notably, the new study led to a 64% increase in the number of known sites. The combined results indicate that prehistory is less represented in the surface record than historical periods, likely due to the impact of soil erosion episodes. The Late Bronze Age and Early Iron Age saw increased site numbers and the emergence of a settlement structure that characterised the area until the Hellenistic period. During the Roman period, the pattern shifted from a seemingly limited use of the landscape towards a model of more extensive habitation. This was driven by the appearance of new rural sites that introduced a land-use regime designed to support agricultural intensification by implementing anti-erosion measures, such as field terraces.
Influence of Livelihood Capitals on Landscape Service Cognition and Behavioral Intentions in Rural Heritage Sites
Authors: Li Shiying , Cheng Yaqi , Cai Jiayu , Zhang Xuewei
Published: October 2024

Farmers’ livelihoods are critical for global sustainable development and the conservation and transmission of rural heritage. However, neglecting farmers’ livelihoods increases the risks to living heritage conservation. Therefore, it is essential to explore the impact of livelihood capital on farmers’ landscape services cognition and their behavioral intentions. Based on the Sustainable Livelihoods Approach, this study examines the rural areas of Mulanbei irrigation district, which was recognized as a World Heritage Irrigation Structure in 2014, and uses a structural equation model to investigate the relationships between farmers’ livelihood capital, landscape services cognition and behavioral intentions. The study’s key findings include the following: (1) The levels of human capital (0.541), social capital (0.671), and cultural capital (0.645) are relatively high, while the levels of natural, physical, and financial capital are comparatively low. (2) There are significant differences in landscape service cognition and behavioral intentions among farmers of different livelihood strategies, with diversified livelihood farmers demonstrating the highest levels of both cognition and intentions, while subsidy-dependent farmers show the lowest levels. (3) Natural, cultural and financial capital play a crucial role in influencing farmers’ landscape services cognition and their behavioral intentions. Landscape service cognition mediates the relationship between livelihood capital and behavioral intentions. (4) To increase farmers’ willingness to protect and promote rural heritage, efforts should focus on enhancing natural, physical, and financial capital while fostering cultural capital to promote advocacy.
Two Decades of Insights: Comprehensive Histopathological and Epidemiological Analysis of Conjunctival Tumors
Authors: Vasović Dolika D. , Rašić Dejan M. , Latković Zoran , Dačić-Krnjaja Bojana , Vasilijević Jelena , Marjanović Ivan , Simonović Jelena , Bobić Radovanović Anica , Karamarković Miodrag , Stojičić Milan , Mićović Milica , Kalezić Tanja
Published: October 2024

This study analyzed 2102 conjunctival lesions excised between 1981 and 2003 at a single tertiary center in Serbia, with the aim of evaluating their histopathological characteristics, anatomical localization, and demographic distribution. Of the total cases recorded, 55.1% were male, indicating a slight male predominance. The bulbar conjunctiva was the most commonly affected site (34.5%), with 39.3% of tumors extended to multiple regions of the conjunctiva, including areas such as the plica and caruncula. The most common benign lesion was compound conjunctival nevus (16.7%), while squamous cell carcinoma (SCC) (11.4%) and melanoma (11.3%) were the most prevalent malignant tumors. Tumor incidence peaked in the 61–70 and 51–60 year age groups, with malignant tumors such as SCC being more frequent in males. Comparisons with similar global studies reveal that our findings align with worldwide trends, such as the predominance of SCC, which has been linked to UV exposure, and the frequency of melanoma in fair-skinned populations. However, the lower prevalence of fibrodegenerative lesions like pterygia and pinguecula in our cohort likely reflects Serbia’s cooler climate compared to regions with higher UV exposure. These findings underscore the diverse nature of conjunctival tumors, the critical role of histopathological examination for diagnosis, and the influence of environmental factors. This study provides valuable insights into the epidemiology of conjunctival tumors, contributing to global understanding and guiding future diagnostic and therapeutic approaches.
Correction: Ulman-Macón et al. Morphological Changes of the Suboccipital Musculature in Women with Myofascial Temporomandibular Pain: A Case-Control Study. Life 2023, 13, 1159
Authors: Ulman-Macón Daniel , Fernández-de-las-Peñas César , Angulo-Díaz-Parreño Santiago , Arias-Buría José L. , Mesa-Jiménez Juan A.
Published: October 2024

Error in Figures [...]
Synthesis of an Insulated Oligo(phenylene ethynylene) Dimer Through Cyclodextrin-Based [c2]Daisy Chain Rotaxane
Authors: Tsuda Susumu , Yasumura Naoto , Fujiwara Shin-ichi , Nishiyama Yutaka
Published: October 2024

Oligo(phenylene ethynylene)s (OPEs) are π-conjugated systems with promising optical, bioactive, and electrical properties, making them valuable candidates for molecular electronics and biosensors. Controlling the arrangement and orientation of π-conjugated systems is crucial in developing molecular devices. Recently, we developed insulated diarylacetylene dimers using a [c2]daisy chain rotaxane strategy, which brings two cores into close proximity without covalent bonding and shields them with permethylated α-cyclodextrins. Here, we synthesized an insulated OPE dimer using a similar rotaxane strategy to investigate its optical properties. The rotaxane structure and optical properties were evaluated using nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization high-resolution mass spectrometry (ESI-HRMS), and absorption and fluorescence spectroscopy. This study is expected to contribute to the development of optical and electronic materials utilizing OPEs.
A Review of Welding Process for UNS S32750 Super Duplex Stainless Steel
Authors: Li Tianqing , Wang Kai , Lei Yucheng
Published: October 2024

Super duplex stainless steel UNS S32750 is widely used in marine industries, pulp and paper industries, and the offshore oil and gas industry. Welding manufacturing is one of the main manufacturing processes to make material into products in the above fields. It is of great importance to obtain high-quality welded UNS S32750 joints. The austenite content and ferrite content in UNS S32750 play an important role in determining UNS S32750 properties such as mechanical properties and corrosion resistance. However, the phase proportion between the ferrite phase and austenite phase in the welded joint will be changed during welding. Lots of research has been done on how to weld UNS S32750 and how to obtain welded joints with good quality. In this work, the recent studies on welding UNS S32750 are categorized based on the welding process. The welding process for UNS S32750 will be classified as gas tungsten arc welding, submerged arc welding, plasma arc welding, laser beam welding, electron beam welding, friction stir welding, and laser-MIG hybrid welding, and each will be reviewed in turn. The microstructure and properties of the joints welded using different welding processes will also be discussed. The critical challenge of balancing the two phases of austenite and ferrite in UNS S32750 welded joints will be discussed. This review about the welding process for UNS S32750 will provide people in the welding field with some advice on welding UNS S32750 super duplex stainless steel.
Synthesis and Characterization of Calcium Sulfoaluminate Hydrates—Ettringite (AFt) and Monosulfate (AFm)
Authors: Szudek Wojciech , Szydłowski Jakub , Buchała Ilona , Kapeluszna Ewa
Published: October 2024

The goal of the presented work was to find the most favorable conditions for the synthesis and stabilization of chemically pure ettringite and monosulfate. The reaction was carried out by mixing pure tricalcium aluminate (C3A) and gypsum (CS¯H2) in an excess amount of water. The impact of hydration time (2–7 days), C3A:CS¯ molar ratio (1:1–1:3) and water vapor pressure of the selected drying agents (anhydrite-III and supersaturated CaCl2 solution) on the phase composition of the products was evaluated. After 7 days of hydration, either ettringite or monosulfate was obtained as the main product, depending on the C3A:CS¯ molar ratio. The synthesis carried out at a C3A:CS¯ molar ratio of 1:3 produced pure ettringite. In the case of the sample characterized by the ratio of 1:1 (typical of monosulfate), a considerable portion of ettringite (27.9%) was present in the final products along the AFm phase. Therefore, a different synthesis method has to be selected in order to obtain pure monosulfate. The results showed that thermal analysis, X-ray diffractometry and FTIR spectroscopy can be used to distinguish the characteristic features of ettringite and monosulfate.
Effect of Surface Roughness on the Electrochemical Behavior and Corrosion Resistance of TiTaNbZrAg Alloy with Different Amounts of Tantalum in Bulk Composition
Authors: Dobri Gabriel , Banu Alexandra , Donath Cristina , Neacsu Elena Ionela , Anastasescu Mihai , Maxim Monica Elisabeta , Vasilescu Cora , Preda Loredana , Marcu Maria
Published: October 2024

The corrosion behavior of the TiTaNbZrAg alloys with different amounts of tantalum (0%, 10% and 20%) and with distinct surface topography (smooth and rough) was investigated in phosphate buffer solution (PBS) for long-time immersion (1000 h). By this approach, we expect to bring about new insights into the influence of both the amount of Ta in the alloy composition and the surface topography on the corrosion behavior of the Ti-based alloys. The corrosion resistance was studied by Open Circuit Potential (OCP), Potentiodynamic Polarization (PP), and Electrochemical Impedance Spectroscopy (EIS). From the potentiodynamic investigations, it was observed that all types of samples showed good corrosion resistance (i.e., Rcorr < 10 µm y−1) and may be used successfully for medical applications. However, the samples with smooth surfaces and with a certain amount of Ta (10% and 20%) exhibit the best corrosion performance (Rcorr < 1 µm y−1). As regards the samples with rough surfaces, the results evidenced that they showed lower corrosion resistance (1 < Rcorr < 3 µm y−1), suggesting that the Ta presence does not necessarily hinder the corrosion processes. Actually, the synergetic effect of both the presence of Ta and surface roughness plays an important role in corrosion resistance.
Enhancing the Photovoltaic Efficiency of In0.2Ga0.8N/GaN Quantum Well Intermediate Band Solar Cells Using Combined Electric and Magnetic Fields
Authors: Abboudi Hassan , En-nadir Redouane , Basyooni-M. Kabatas Mohamed A. , El Baraka Ayoub , Belaid Walid , Ez-zejjari Ilyass , El Ghazi Haddou , Jorio Anouar , Zorkani Izeddine
Published: October 2024

This study presents a theoretical investigation into the photovoltaic efficiency of InGaN/GaN quantum well-based intermediate band solar cells (IBSCs) under the simultaneous influence of electric and magnetic fields. The finite element method is employed to numerically solve the one-dimensional Schrödinger equation within the framework of the effective-mass approximation. Our findings reveal that electric and magnetic fields significantly influence the energy levels of electrons and holes, optical transition energies, open-circuit voltages, short-circuit currents, and overall photovoltaic conversion performances of IBSCs. Furthermore, this research indicates that applying a magnetic field positively influences conversion efficiency. Through the optimization of IBSC parameters, an efficiency of approximately 50% is achievable, surpassing the conventional Shockley–Queisser limit. This theoretical study demonstrates the potential for next-generation photovoltaic technology advancements.
Shear Performance of RC Beams Strengthened with High-Performance Fibre-Reinforced Concrete (HPFRC) Under Static and Fatigue Loading
Authors: Liu Xiangsheng , Thermou Georgia E.
Published: October 2024

This study experimentally assessed the shear performance of reinforced concrete (RC) beams strengthened with U-shaped High-Performance Fibre-Reinforced Concrete (HPFRC) under static and fatigue loading. Key parameters included HPFRC jacket thickness and beam shear span–depth (a/d) ratio. Five beams were tested under static loads to determine ultimate shear strengths, followed by fatigue tests on identical beams at 30–70% of ultimate shear strengths at 4 Hz. In static loading experiments, all the HPFRC jacketing proved effective, increasing the shear strength of RC beams by 95% to 130%. Although the strengthening system did not change the failure mode of the beams, the strengthened beams exhibited pseudo-ductile behaviour. As the a/d increased, the shear enhancement capability of the HPFRC jackets decreased. In fatigue loading experiments, all the HPFRC systems improved the fatigue life of RC beams. Specifically, in beams with an a/d ratio of 2.0, the fatigue life was extended from 75 cycles to a maximum of 951 cycles, while in beams with an a/d ratio of 3.5, it increased from 12,525 cycles to 48,786 cycles. In addition, a predictive model has been developed for the fatigue life of HPFRC/UHPFRC shear-strengthened beams, utilising the maximum fatigue load and the design’s ultimate shear strength under static loading conditions.
Evaluation of Reusable Thermal Protection System Materials Using a High-Velocity Oxygen Fuel Torch
Authors: Chinnaraj Rajesh Kumar , Kim Minjeong , Choi Bogyu , Ha Taerin , Kim Seongwon , Nam Min-Soo , Choi Seong Man
Published: October 2024

We studied a candidate TPS (thermal protection system) material for reusable re-entry space vehicle applications. The material was based on a high-temperature-resistant material called Cerakwool. A total of six specimens were fabricated with substrate densities of 0.45 g/cm3, 0.40 g/cm3, and 0.35 g/cm3, with two specimens for each density. All specimens were coated with high-emissivity TUFI (toughened unpiece fibrous insulation), with coating thicknesses ranging from 445 to 1606 µm. The specimens were tested using an HVOF (high-velocity oxygen fuel) material ablation test facility. For each density specimen pair, one specimen was tested at 1 MW/m2 and the remaining one was tested at 0.65 MW/m2. The average stagnation point temperature for specimens tested at 1 MW/m2 was ~893 °C, approximately 200 °C higher than those tested at 0.65 MW/m2. This suggests a ~200 °C increase in stagnation point temperature for a 0.35 MW/m2 rise in incident heat flux. During the tests, internal temperatures were measured at three locations. For all tested specimens, regardless of heat flux test conditions and density, the temperature at ~40 mm from each specimen’s stagnation point remained around or below 50 °C, well within the 180 °C design limit set for the TPS back face temperature. Post-test visual inspections revealed no signs of ablation or internal damage, confirming the material’s reusability.
Development of Biodegradable and Recyclable FRLM Composites Incorporating Cork Aggregates for Sustainable Construction Practices
Authors: Pugliese Dora , Alecci Valerio , Tale Masoule Mohammad Sadegh , Ghahremaninezhad Ali , De Stefano Mario , Nanni Antonio
Published: October 2024

Reducing energy consumption in the building sector has driven the search for more sustainable construction methods. This study explores the potential of cork-modified mortars reinforced with basalt fabric, focusing on optimizing both mechanical and hygroscopic properties. Six mortar mixtures were produced using a breathable structural mortar made from pure natural hydraulic lime, incorporating varying percentages (0–3%) of cork granules (Quercus suber) as lightweight aggregates. Micro-computed tomography was first used to assess the homogeneity of the mixtures, followed by flow tests to evaluate workability. The mixtures were then tested for water absorption, compressive strength, and adhesion to tuff and clay brick surfaces. Adhesion was measured through pull-off tests, to evaluate internal bonding strength. Additionally, this study examined the relationship between surface roughness and bond strength in FRLM composites, revealing that rougher surfaces significantly improved adhesion to clay and tuff bricks. These findings suggest that cork-reinforced mortars offer promising potential for sustainable construction, achieving improved hygroscopic performance, sufficient mechanical strength, internal bonding, and optimized surface adhesion.
Properties of Wedge Wire Bonded Connection Between a Composite Copper Core Aluminum Shell Wire and an 18650 Cylindrical Lithium-Ion Battery Cell
Authors: Bieliszczuk Krzysztof , Chmielewski Tomasz M.
Published: October 2024

Wedge wire bonding is a solid-state joining process that uses ultrasonic vibrations in combination with compression of the materials to establish an electrical connection. In the battery industry, this process is used to interconnect cylindrical battery cells due to its ease of implementation, high flexibility and ease of automation. Wire materials typically used in battery pack manufacturing are pure or alloyed aluminum and copper. While copper wires possess better electrical properties, the force used in the bonding process can lead to cell isolator damage and cell thermal runaway. This is an unacceptable result of the bonding process and has led to the development of new types of composite wires containing a copper core embedded in an aluminum shell. This material has the advantage of high copper electrical and thermal conductivity combined with less aggressive bonding parameters of the aluminum wire. The aim of this study was to establish a process window for the wedge wire bonding of 400 µm composite copper–aluminum Heraeus CucorAl Plus wire on the surface of a BAK 18650 battery cell. This study was conducted using a Hesse Bondjet BJ985 CNC wire bonder fitted with an RBK03 bond head designed for the bonding of copper wires. The methods used in this study included light and scanning electron microscopy of bond and battery cell cross-sections, shear testing on the XYZtec Sigma bond tester system, and energy dispersive spectroscopy. The results were compared with a previous study conducted using a wire of the same diameter and made out of high-purity aluminum.
SIMS and Numerical Analysis of Asymmetrical Out-Diffusion of Hydrogen and Carbon in CdxZn1−xO:Eu Multilayer
Authors: Khosravizadeh Zeinab , Lysak Anastasiia , Przeździecka Ewa , Jakieła Rafał
Published: October 2024

This study employs secondary ion mass spectrometry (SIMS) to investigate the diffusion behavior of hydrogen and carbon in a CdxZn1−xO:Eu multilayer at different annealing temperatures (500–900 °C). The SIMS results reveal a significant out-diffusion of these elements toward the surface and diffusion to the interface region. The diffusion flow rates are asymmetric and favor the interface direction. The depth profiles of diffused elements are fitted using the forward timecentered space (FTCS) iteration method. The activation energies are determined to be 0.35 ± 0.06 eV for hydrogen and 0.33 ± 0.09 eV for carbon, suggesting an interstitial mechanism in CdxZn1−xO. The results indicate that increasing the annealing temperatures leads to a significant decrease in impurity concentrations.
Large Room-Temperature Electrocaloric Effect in Lead-Free Relaxor Ferroelectric Ceramics with Wide Operation Temperature Range
Authors: Zhao Xiaobo , Zhou Zhiyong , Liang Bo , Lu Shengguo
Published: October 2024

In order to obtain large room-temperature electrocaloric effect (ECE) and wide operation temperature range simultaneously in lead-free ceramics, we proposed designing a relaxor ferroelectric with a Tm (the temperature at which the maximum dielectric permittivity is achieved) near-room temperature and glass addition. Based on this strategy, we designed and fabricated lead-free 0.76NaNbO3–0.24BaTiO3 (NN-24BT) ceramics with 1wt.% BaO–B2O3–SiO2 glass addition, which showed distinct relaxor ferroelectric characteristics with strongly diffused phase transition and a Tm near-room temperature. Based on a direct measurement method, a large ΔT (adiabatic temperature change) of 1.3 K was obtained at room temperature under a high field of 11.0 kV mm−1. Additionally, large ECE can be maintained (>0.6 K@6.1 kV mm−1) over a broad temperature range from 23 °C to 69 °C. Moreover, the ECE displayed excellent cyclic stability with a variation in ΔT below ±7% within 100 test cycles. The comprehensive ECE performance is significantly better than other lead-free ceramics. Our work provides a general and effective approach to designing lead-free, high-performance ECE ceramics, and the approach possesses the potential to be utilized to improve the ECE performance of other lead-free ferroelectric ceramic systems.
Evaluation and Optimization of Cement Slurry Systems for Ultra-Deep Well Cementing at 220 °C
Authors: Zhang Zhi , Ai Zhengqing , Yang Lvchao , Zhang Yuan , Pang Xueyu , Yuan Zhongtao , Liu Zhongfei , Sun Jinsheng
Published: October 2024

With the depletion of shallow oil and gas resources, wells are being drilled to deeper and deeper depths to find new hydrocarbon reserves. This study presents the selection and optimization process of the cement slurries to be used for the deepest well ever drilled in China, with a planned vertical depth of 11,100 m. The bottomhole circulating and static temperatures of the well were estimated to be 210 °C and 220 °C, respectively, while the bottomhole pressure was estimated to be 130 MPa. Laboratory tests simulating the bottomhole conditions were conducted to evaluate and compare the slurry formulations supplied by four different service providers. Test results indicated that the inappropriate use of a stirred fluid loss testing apparatus could lead to overdesign of the fluid loss properties of the cement slurry, which could, in turn, lead to abnormal gelation of the cement slurry during thickening time tests. The initial formulation given by different service providers could meet most of the design requirements, except for the long-term strength stability. The combined addition of crystalline silica and a reactive aluminum-bearing compound to oil well cement is critical for preventing microstructure coarsening and strength retrogression at 220 °C. Two of the finally optimized cement slurry formulations had thickening times more than 4 h, API fluid loss values less than 50 mL, sedimentation stability better than 0.02 g/cm3, and compressive strengths higher than 30 MPa during the curing period from 1 d to 30 d.
Evaluation of the Applicability of Waste Rubber in Insulation Panels with Regard to Its Grain Size and Panel Thickness
Authors: Cimbola Zdravko , Crnoja Anđelko , Barišić Ivana , Netinger Grubeša Ivanka
Published: October 2024

This paper explores the effect of waste rubber grain size on the porosity, modulus of elasticity, thermal properties, and soundproofing performance of polymer composites with different thicknesses (10, 15, and 20 mm). All properties were tested in accordance with European standards, with the exception of porosity, which was measured using Archimedes’ principle. The findings indicate that with a consistent amount of polyurethane glue, finer rubber grains result in composites with higher porosity, leading to a lower modulus of elasticity but enhanced thermal and sound insulation. In contrast, coarser rubber grains produced composites with lower porosity and a higher modulus of elasticity, though with slightly reduced thermal insulation and significantly worse soundproofing. A combination of fine and coarse rubber grains provided a balanced performance, offering both good thermal and sound insulation while maintaining a high modulus of elasticity. Among the thicknesses tested, 15 mm was identified as optimal, combining a relatively high modulus of elasticity, low thermal conductivity, and better airborne sound insulation index. Future research will focus on applying this composite in concrete building products that meet noise protection and energy efficiency standards.