bluuebunny/crossref_metadata_2025 huggingface dataset:
Pseudochamber-Protected Keratoplasty (PPK) with a New Inter-Corneal Surgical Device Implant Technique in High-Risk Cases
Authors: Alfonso José F. , Lisa Carlos , Alfonso-Bartolozzi Belén , Alvarado-Villacorta Rosa , Madrid-Costa David , Fernández-Vega-Cueto Luis
Published: September 2024

Background/Objectives: To describe the pseudochamber-protected keratoplasty (PPK) procedure with the new Endo-K Pro® implant technique and report the clinical outcomes in patients at high risk for penetrating keratoplasty (PKP). Methods: This case series study included patients who required a PKP and had a high risk for corneal transplant failure. All cases underwent the PPK procedure with simultaneous Endo-K Pro® implantation and had a minimum follow-up of 12 months. Graft survival was the primary outcome (defined as a clear graft with an endothelial cell density >500 cells/mm2). Central corneal thickness (CCT), corrected distance visual acuity (CDVA), intraocular pressure (IOP), and complication rate were the secondary outcomes. Results: Twenty-five eyes (twenty-five patients) were included. The mean follow-up was 23.64 ± 8.2 months (range: 12–36 months). Graft survival was achieved in 23 of the 25 cases (92%). One eye had to be re-transplanted due to persistent oedema secondary to uncontrolled IOP. In two cases (8%), the graft failed three months after surgery when an anterior pseudochamber collapsed due to direct contact of donor endothelium and host tissue. Six eyes experienced host tissue protrusion that was successfully managed using an Nd: YAG laser (two eyes) or injecting a cohesive viscoelastic into the pseudochamber (four eyes). CDVA increased significantly during the follow-up period. No significant changes were found in IOP. No intra- or postoperative complications were reported. Conclusions: PPK with the Endo-K Pro® implant seems to be an effective and safe surgical approach as an alternative in high-risk patients for PKP, allowing full-thickness corneal transplantation without performing an open-sky procedure.
Role of Spirometry, Radiology, and Flexible Bronchoscopy in Assessing Chronic Cough in Children
Authors: Boonjindasup Wicharn , Thomas Rahul J. , Yuen William , McElrea Margaret S.
Published: September 2024

Chronic cough in children is a common and multifaceted symptom, often requiring a comprehensive approach for accurate diagnosis and effective management. This review explores the use of spirometry, radiology (chest X-rays and computed tomography (CT) scans), and flexible bronchoscopy in the assessment of chronic cough in children through current guidelines and studies. The strengths, clinical indications, and limitations of each modality are examined. Spirometry, radiology, and in some cases flexible bronchoscopy are integral to the assessment of chronic cough in children; however, a tailored approach, leveraging the strengths of each modality and guided by clinical indications, enhances diagnostic accuracy and therapeutic outcomes of pediatric chronic cough.
Immunotherapy in Basal Cell Carcinoma
Authors: Ungureanu Loredana , Vasilovici Alina Florentina , Halmágyi Salomea-Ruth , Trufin Ioana Irina , Apostu Adina Patricia , Prisecaru Manuela , Șenilă Simona Corina
Published: September 2024

Basal cell carcinoma (BCC) is the most frequent of all cancers, with an increasing incidence. The first line therapy is surgical excision, but topical therapies can be used in low-risk superficial BCCs, while the more advanced, unresectable, or metastatic BCCs benefit from systemic therapies with hedgehog inhibitors and immunotherapy. The purpose of this review is to highlight local and systemic immunotherapies and their efficacy in the management of BCCs. Local therapies can be considered in superficial and low-risk nodular BCCs, with imiquimod frequently used for its antitumor and immunoregulatory properties. Imiquimod alone demonstrated higher histological clearance rates, but patients treated with imiquimod experienced more adverse events than ones treated with other therapies. Imiquimod can be used as an adjuvant before Mohs micrographic surgery and can also be combined with other local therapies, like curettage, electrodesiccation, cryosurgery, and photodynamic therapy, with some treatment methods yielding results comparable with the surgery. Interferons and Interleukin-2 were evaluated in a small number of studies with different results. Systemic immunotherapies with programmed death-ligand 1 (PD-L1) inhibitors showed inconsistent results in patients with advanced BCCs, being effective in some patients that progressed on or were intolerant to hedgehog pathway inhibitors (HHI).
Location and Extent of Paravascular Nerve Fiber Layer Clefts in Eyes with Epiretinal Membranes
Authors: Petersen Sekita Dalsgård , Christensen Ulrik Correll , Larsen Michael
Published: September 2024

Purpose: The clinical use of en face optical coherence tomography (OCT) has revealed nerve fiber layer clefts in the retinal nerve fibers in eyes with macula-centered epiretinal membranes (ERMs). The purpose of this study is to describe the location and the extent of retinal nerve fiber layer (RNFL) clefts in eyes with symptomatic ERMs. Methods: We conducted a retrospective review of 17 individual eyes in 17 patients with symptomatic ERMs and a control group of 10 healthy eyes from 10 subjects who had been examined for unrelated causes. The examinations performed included best-corrected visual acuity, rebound tonometry, fundus photography, structural OCT and angiographic OCT (OCTA) made in the form of 12 × 12 mm angiographic volume scans. Results: Hyporeflective RNFL clefts, seen in 14 out of 17 eyes with ERMs, were sharply demarcated in the en face presentation of slabs extending from the internal limiting membrane through the RNFL or including only the latter. The clefts were capillary-free on OCTA scans and formed depressions of the retinal surface. Most of the clefts were adjacent to and followed the course of the retinal trunk vessels, but clefts were also seen along smaller macular vessels and beyond the retinal vascular arcades. Conclusions: Paravascular RNFL clefts can be observed beyond the vascular arcades and adjacent to small vessels on OCTA block scan data. This suggests that the direction and magnitude of tractional displacement of the inner retina in eyes with epimacular membranes can extend beyond the vascular arcades and add to an improved analysis of abnormal fundus findings.
Clinical Evaluation of Acute Exacerbation of Interstitial Lung Disease in a Single Tertiary Center: Perspectives before and after the Coronavirus Disease 2019 Pandemic
Authors: Takagi Ryo , Saraya Takeshi , Yamada Sho , Nakajima Kei , Doi Kazuyuki , Akizawa Takatora , Ishikawa Narishige , Kurokawa Nozomi , Kobayashi Fumi , Nunokawa Hiroki , Aso Jumpei , Nakamoto Yasuo , Ishida Manabu , Sada Mitsuru , Honda Kojiro , Nakamoto Keitaro , Takata Saori , Ishii Haruyuki
Published: September 2024

Background/Objectives: Acute exacerbation (AE) of interstitial lung disease (ILD) is a major challenge. This study aimed to retrospectively investigate occurrences of AEs in patients with ILDs, including idiopathic pulmonary fibrosis (IPF), non-IPF (iNSIP: idiopathic nonspecific interstitial pneumonia), and connective tissue disease (CTD)-associated ILDs (CTD-ILDs), at a single tertiary center before and after the coronavirus disease 2019 (COVID-19) pandemic. The study aimed to clarify the seasonal and regional trends of AEs of ILDs, assess the roles of viral and bacterial infections, and identify key prognostic factors for patient outcomes. Methods: We conducted a retrospective review of hospitalized adult patients with AEs of ILDs from January 2019 to February 2024. Results: A total of 93 patients were enrolled: IPF (n = 42), iNSIP (n = 37), and CTD-ILDs (n = 14). The median age was 80 years (interquartile range: 74.0–86.0 years), with males comprising 64.5% (n = 60). AEs of ILDs predominantly occurred in winter and were particularly notable after summer 2023, coinciding with the lifting of COVID-19-related travel restrictions in Japan. Patient referrals from different areas (Northern Tama, East and/or Southern Tama, and other Tokyo metropolitan areas) were evenly distributed throughout the study period. Viral infections were detected in only two patients (SARS-CoV-2), and bacterial infections included methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. The Cox regression analysis identified serum lactate dehydrogenase levels ≥350 IU/L and tachypnea (respiratory rate ≥ 30 breaths per min) on admission as prognostic factors for mortality, with a hazard ratio [HR] of 2.783 (95% confidence interval [CI]: 1.480–5.235, p = 0.001) and an HR of 3.332 (95% CI: 1.710–6.492, p < 0.001), respectively. Conclusions: AEs of ILDs predominantly occur in winter, and viral and bacterial infections are infrequently detected. Elevated serum LDH levels and tachypnea are crucial prognostic markers for mortality. This study highlights the seasonal trend in the AE of ILD and emphasizes the importance of specific prognostic indicators in clinical practice.
Nociplastic Pain: A Critical Paradigm for Multidisciplinary Recognition and Management
Authors: Ablin Jacob N.
Published: September 2024

Our understanding of chronic pain has evolved significantly, shifting from a focus on peripheral damage to recognizing the central mechanisms underlying pain perception. This perspective article explores the concept of nociplastic pain, a term introduced by the International Association for the Study of Pain (IASP) in 2017, which describes pain arising from altered pain modulation within the central nervous system, without clear evidence of tissue damage or inflammation. The historical progression from fibrositis to fibromyalgia, and now to nociplastic pain, underscores the complexity of chronic pain syndromes and the need for a multidisciplinary approach to management. Nociplastic pain is characterized by central sensitization, leading to heightened pain sensitivity and often accompanied by comorbidities such as fatigue, sleep disturbances, and cognitive difficulties. Advances in neuroimaging have revealed altered connectivity within key brain networks, such as the default mode and salience networks, in patients with nociplastic pain, providing insights into the neural underpinnings of this condition. The article also addresses controversies surrounding the role of small fiber neuropathy and autonomic dysfunction in nociplastic pain, highlighting the ongoing debates in the field. The practical importance of recognizing nociplastic pain across various medical disciplines—including primary care, orthopedics, neurology, psychiatry, and rheumatology—is emphasized, with recommendations for integrating this knowledge into clinical practice. Emerging therapies, such as neurofeedback, hyperbaric oxygen therapy, and neuromodulation, offer new avenues for treatment, particularly for patients who do not respond to conventional approaches. The article calls for continued research into the mechanisms of nociplastic pain, the development of reliable diagnostic tools, and the exploration of novel therapeutic strategies to improve patient outcomes. The recognition and management of nociplastic pain are crucial for advancing the care of patients with chronic pain, necessitating interdisciplinary collaboration and a patient-centered approach.
Strategies Used by Puerto Rican Children in the Cognitive Assessment System and Their Relationship with Planning Performance
Authors: Cordero-Arroyo Giselle , Ramos-Carrasquillo José A. , Cruz-Figueroa Imalay M. , Báez-Ávila Loggina , Gonzalez-Gonzalez Manuel , Moreno-Torres Mary A. , Bermonti-Pérez Mario E.
Published: September 2024

Studies involving the Cognitive Assessment System (CAS) planning scale typically use only the subtest and scale scores without assessing the strategies employed by the participants. This study addressed this gap and examined the planning strategies used by children in the CAS2: Spanish version and their relationship with planning performance. We conducted an exploratory cross-sectional study with 26 Puerto Rican children aged 8 to 11. Results showed that no strategies were consistently used by participants according to examinees’ reports (f = 0–46%), but examiners observed consistent use of some strategies such as “coded left to right, top to bottom”, f = 92%; “scanned the page for the next number or letter”, f = 100%. Welch’s t-tests did not show relationships between participants’ performance and the strategies observed by examiners, | mean differences | = 0.05–0.81, ps ≥ 0.05, nor with the strategies reported by participants, | mean differences | = 0.05–1.69, ps ≥ 0.05. These findings suggest that although the examiners may observe the use of strategies, the examinees are unaware of the strategies they use, and the strategies used are not associated with their performance. Future studies are needed to confirm these findings.
Correction: Grinschgl et al. (2023). Who Wants to Enhance Their Cognitive Abilities? Potential Predictors of the Acceptance of Cognitive Enhancement. Journal of Intelligence 11: 109
Authors: Grinschgl Sandra , Berdnik Anna-Lena , Stehling Elisabeth , Hofer Gabriela , Neubauer Aljoscha C.
Published: September 2024

There were errors in the original publication Grinschgl et al [...]
Applying Machine Learning and SHAP Method to Identify Key Influences on Middle-School Students’ Mathematics Literacy Performance
Authors: Huang Ying , Zhou Ying , Chen Jihe , Wu Danyan
Published: September 2024

The PISA 2022 literacy assessment highlights a significant decline in math performance among most OECD countries, with the magnitude of this decline being approximately three times that of the previous round. Remarkably, Hong Kong, Macao, Taipei, Singapore, Japan, and Korea ranked in the top six among all participating countries or economies, with Taipei, Singapore, Japan, and Korea also demonstrating improved performance. Given the widespread concern about the factors influencing secondary-school students’ mathematical literacy, this paper adopts machine learning and the SHapley Additive exPlanations (SHAP) method to analyze 34,968 samples and 151 features from six East Asian education systems within the PISA 2022 dataset, aiming to pinpoint the crucial factors that affect middle-school students’ mathematical literacy. First, the XGBoost model has the highest prediction accuracy for math literacy performance. Second, 15 variables were identified as significant predictors of mathematical literacy across the student population, particularly variables such as mathematics self-efficacy (MATHEFF) and expected occupational status (BSMJ). Third, mathematics self-efficacy was determined to be the most influential factor. Fourth, the factors influencing mathematical literacy vary among individual students, including the key influencing factors, the direction (positive or negative) of their impact, and the extent of this influence. Finally, based on our findings, four recommendations are proffered to enhance the mathematical literacy performance of secondary-school students.
Reliability Enhancement Methods for Relaxation Oscillator with Delay Time Cancellation
Authors: Xu Kunpeng , Dai Hongguang , Wu Zhanxia , Huang Zhibo , Zhang Guoqiang , Yu Xiaopeng , Wang Weichang , Xuan Gang
Published: September 2024

Relaxation oscillators are preferred in low-frequency applications due to their lower power consumption and superior temperature stability. However, frequency errors arise from variations in the comparator’s offset voltage and delay time due to PVT changes. To address these issues, this paper proposes the low-power delay time cancellation (DTC) technique and several enhancement methods, including a novel offset trimming approach, an error state detection and recovery (ESDAR) circuit, and a specialized frequency-trimming method. Simulation results for an 8 MHz relaxation oscillator in a 40 nm CMOS process show that the proposed DTC technique and enhancements improve frequency variation due to power supply fluctuations to ±0.05% and reduce temperature-induced frequency variation to ±0.4%.
Subthalamic Stimulation Improves Short-Term Satisfaction with Life and Treatment in Parkinson’s Disease
Authors: Sauerbier Anna , Bachon Pia , Ambrosio Leire , Loehrer Philipp A. , Rizos Alexandra , Jost Stefanie T. , Gronostay Alexandra , Fink Gereon R. , Ashkan Keyoumars , Nimsky Christopher , Visser-Vandewalle Veerle , Chaudhuri K. Ray , Timmermann Lars , Martinez-Martin Pablo , Dafsari Haidar S.
Published: September 2024

The effect of subthalamic stimulation (STN-DBS) on patients’ personal satisfaction with life and their Parkinson’s disease (PD) treatment is understudied, as is its correlation with quality of life (QoL). Therefore, we tested the hypothesis that STN-DBS for PD enhances satisfaction with life and treatment. In a prospective, multicenter study with a 6-month follow-up involving 121 patients, we measured the main outcomes using the Satisfaction with Life and Treatment Scale (SLTS-7). Secondary outcomes included the eight-item PD Questionnaire (PDQ-8), European QoL Questionnaire (EQ-5D-3L), EQ-Visual Analogue Scale (VAS), Non-Motor Symptom Scale (NMSS), Hospital Anxiety and Depression Scale (HADS), and Unified PD Rating Scale (UPDRS). Longitudinal outcome changes, effect sizes (Cohen’s d), and correlations between outcome changes were analyzed. SLTS-7 scores improved at the 6-month follow-up, particularly in the domains of ‘satisfaction with physical health’ and ‘satisfaction with treatment’. Change scores correlated strongly (EQ-VAS), moderately (PDQ-8 SI and HADS), and weakly (UPDRS-activities of daily living and EQ-5D-3L) with other scales. Satisfaction with physical health, psychosocial well-being, or treatment was not related to UPDRS-motor examination. This study provides evidence that STN-DBS enhances patients’ personal satisfaction with life and treatment. This satisfaction is associated with improvements in the QoL, daily activities, and neuropsychiatric aspects of PD rather than its motor aspects.
Population Heterogeneity and Selection of Coronary Artery Disease Polygenic Scores
Authors: Debernardi Carla , Savoca Angelo , De Gregorio Alessandro , Casalone Elisabetta , Rosselli Miriam , Herman Elton Jalis , Di Primio Cecilia , Tumino Rosario , Sieri Sabina , Vineis Paolo , Panico Salvatore , Sacerdote Carlotta , Ardissino Diego , Asselta Rosanna , Matullo Giuseppe
Published: September 2024

Background/Objectives: The identification of coronary artery disease (CAD) high-risk individuals is a major clinical need for timely diagnosis and intervention. Many different polygenic scores (PGSs) for CAD risk are available today to estimate the genetic risk. It is necessary to carefully choose the score to use, in particular for studies on populations, which are not adequately represented in the large datasets of European biobanks, such as the Italian one. This work aimed to analyze which PGS had the best performance within the Italian population. Methods: We used two Italian independent cohorts: the EPICOR case–control study (576 individuals) and the Atherosclerosis, Thrombosis, and Vascular Biology (ATVB) Italian study (3359 individuals). We evaluated 266 PGS for cardiovascular disease risk from the PGS Catalog, selecting 51 for CAD. Results: Distributions between patients and controls were significantly different for 49 scores (p-value < 0.01). Only five PGS have been trained and tested for the European population specifically. PGS003727 demonstrated to be the most accurate when evaluated independently (EPICOR AUC = 0.68; ATVB AUC = 0.80). Taking into account the conventional CAD risk factors further enhanced the performance of the model, particularly in the ATVB study (p-value = 0.0003). Conclusions: European CAD PGS could have different risk estimates in peculiar populations, such as the Italian one, as well as in various geographical macro areas. Therefore, further evaluation is recommended for clinical applicability.
Soil Classification Based on Local and Scientific Knowledge in an Irrigated District in the Semi-Arid Region of Brazil
Authors: Silva Jucirema Ferreira da , Ferreira Neto Miguel , Portela Jeane Cruz , Gondim Joaquim Emanuel Fernandes , Melo Stefeson Bezerra de , Freitas Diana Ferreira de , Medeiros José Francismar de , Dias Nildo da Silva , Peixoto Tayd Dayvison Custódio , Sá Francisco Vanies da Silva
Published: September 2024

Ethnopedology offers a unique opportunity to recognize and highlight invaluable local soil knowledge (LSK). We aimed to classify three soil profiles in a Brazilian irrigated district with salt-affected soils based on smallholder farmers’ LSK and scientific knowledge. The study occurred in the Baixo-Açu irrigation district in Brazil’s semi-arid region. Three soil profiles were characterized by researchers (etic approach) and farmers (emic approach) in the following areas: P1 profile (area under banana cultivation), P2 profile (fallow area), and P3 profile (native forest area). Smallholder farmers identified the studied areas with salt problems based on the salt precipitation on the surface, changes in leaf color, and incidence of indicator plants of salinized areas. Researchers classified P1 profile as Pantohypereutric Calcaric Leptic Cambisol (Loamic, Humic), P2 as Pantohypereutric Calcaric Leptic Cambisol (Loamic, Humic), and P3 as Leptic Calcic Chernozem (Loamic). Smallholder farmers classified the P1 profile as “Terra de Salitre” (Salt Soil), the P2 profile as “Terra de Piçarro” (Saprolite Soil), and the P3 profile as “Terra Boa” (Good Soil). The results indicate that valuing local soil knowledge is effective and crucial for improved scientific research and land use, highlighting the importance of recognizing and utilizing their expertise and experience.
The Impact of Park Green Space Areas on Urban Vitality: A Case Study of 35 Large and Medium-Sized Cities in China
Authors: Wu Guancen , Yang Dongqin , Niu Xing , Mi Zixuan
Published: September 2024

Urban park green spaces not only significantly enhance urban environmental quality, but also increase social interactions, making them a crucial factor in urban vitality, particularly in densely populated and ecologically stressed metropolitan areas. This study utilizes panel data from 35 major cities in China from 2012 to 2022 to analyze the impact of per capita urban park green space areas on urban vitality. The results confirm the significant effect of per capita park green space areas on urban vitality. However, this impact diminishes under the single-threshold conditions of GDP and total park green space areas, as well as the double-threshold condition of total population. Based on these findings, the study proposes policy recommendations emphasizing the importance of park green space construction to promote sustainable urban development and improve residents’ quality of life.
From Solo to Cluster Governance: An Empirical Study of Transforming Rural Management in Guiyang, China
Authors: Liu Hailing , Fan Wenjun , Zhou Xiaoyu , Wang Yuting , Yuan Chengcheng , Liu Liming
Published: September 2024

As China shifts from urbanization to rural revitalization within its rural governance strategy, devising appropriate governance programs becomes crucial for the effective implementation of overarching strategies. This paper explores the policy pathway of the rural revitalization strategy via the lens of village relational governance. This paper builds a relational network of village governance using the Newtonian gravity model and proposes an effective relational governance policy by analyzing the impact of village cluster patterns under different policy rules. Empirical research was conducted in Guiyang County, Hunan Province, China. The findings of this paper are as follows. (1) Rural development in Guiyang County heavily relies on location advantages and natural resources, and there is an urgent need to reinvent the path of rural governance to foster potential rural clusters. (2) A comparative analysis of the relational networks shows that the assignment-based network has more high-clustering groups and fewer low-clustering clusters than the merit-based network, and it has more cluster types, resulting in a more balanced and diverse network structure. In contrast, the merit-based network has fewer cluster types and tends to have a centralized structure. (3) The assignment-type network has greater advantages in terms of agricultural productivity, preserving local culture, and protecting the environment. Simultaneously, its network path has the potential to boost the intrinsic vitality of rural areas and attract more groups to contribute to its development. This path is feasible due to the high level of organization within the Chinese villages. Consequently, this study recommends that the county government should actively decentralize power to villages and grant villages equal development rights to encourage villages to build network clusters with unique competitive advantages.
Conceptualization of Supplier Involvement in Product Development Based on a Systematic Review of 47 Definitions
Authors: Flankegård Filip , Johansson Glenn , Granlund Anna , Johansson Peter E.
Published: September 2024

Background: Supplier involvement in product development has proven beneficial for companies and is a phenomenon researched in various domains. The definitions of supplier involvement represent points of origin and dimensions addressed in research. Still, there is no overview of these definitions and dimensions. This study reviews current definitions of the phenomenon of supplier involvement in product development and develops a conceptual model outlining its main dimensions. Methods: A systematic literature review is conducted to provide an overview of explicit definitions of supplier involvement in product development. By identifying the elements of these definitions, a conceptual model is developed to demonstrate how the phenomenon has been conceptualized in literature. Results: The results include an overview of 47 explicit definitions of supplier involvement in product development, a conceptual model including the identified dimensions, research gaps, and questions for future research. Conclusions: Supplier involvement in product development is a complex phenomenon with interdependencies between its key dimensions. A conceptual model of supplier involvement is presented, which is useful for categorizing research to identify research gaps and avenues for future research.
A Multi-Feature Fusion Method for Life Prediction of Automotive Proton Exchange Membrane Fuel Cell Based on TCN-GRU
Authors: Zhang Jiaming , Yan Fuwu , Du Changqing , Zhang Yiming , Zheng Chao , Wang Jinhai , Chen Ben
Published: September 2024

The Proton Exchange Membrane Fuel Cell (PEMFC) is a fast-developing battery technology, and the key to its reliability and lifespan improvement lies in the accurate assessment of durability. However, the degradation mechanism of the PEMFC is hard to determine and its internal parameters are highly coupled. Thus, the development of a more accurate life prediction model that meets the actual scenarios is to be investigated urgently. To solve this problem, a multi-feature fusion life prediction method based on the Temporal Convolutional Network-Gated Recurrent Unit (TCN-GRU) is proposed. A TCN algorithm is used as the prediction base model, and two GRU modules are included with the model to strengthen the model’s expression ability and improve its predictive accuracy. Two widely recognized datasets and two operating conditions are utilized for model training and prediction, respectively. Comparisons are made with single-feature parameter models in terms of Root Mean Square Error (RMSE) and the Determination Coefficient (R2). The results show that the prediction accuracy of the TCN-GRU multi-feature fusion model is higher than that of the single-feature models in terms of stability and anti-interference under both operating conditions. The accuracy of the TCN-GRU (three-feature) model is the most optimal in a steady-state condition at 80% of the training set ratio (RMSE = 3.27 × 10−3, R2 = 0.965). Furthermore, with the increase in the input feature parameter, the TCN-GRU model is closer to the real value, which proves once again that the proposed model can meet the accuracy requirements of the life prediction of the PEMFC.
Influence of Heat Treatment Temperature on Microstructure, Hardness and Sensitization of UNS S32205 Duplex Stainless Steel
Authors: Quadros Pedro Victorio Caetano Abrantes , Ribeiro Jomar José Knaip , Schibicheski Kurelo Bruna Corina Emanuely , Palma Calabokis Oriana , Nuñez de la Rosa Yamid E. , Turin Alba Regina , Borges Paulo César
Published: September 2024

Improper thermal cycles on duplex stainless steels can lead to the formation of detrimental phases or alter the proportion of ferrite and austenite phases, thus influencing the material’s mechanical properties and corrosion resistance. Therefore, this study aimed to evaluate the effect of aging (at 850 and 950 °C) and solubilization (at 1000 and 1150 °C) thermal treatments on microstructure, indentation hardness, elasticity modulus, and susceptibility to intergranular corrosion of UNS S32205 duplex stainless steel. The sigma phase (σ) formation in the aged samples, with hardness values between 8 and 10 GPa, was confirmed. Furthermore, the pieces treated from 1000 °C upwards showed that increased temperature favored the formation of more equiaxial grains and the ferrite fraction growth. The thermal treatments barely affected the elasticity modulus of austenite and ferrite grains, increasing the hardness of ferrite. The effect of sulfuric acid concentration in the intergranular corrosion was evaluated. Also, the deconvolution of the corrosion curves permits the determination of the influence of the different phases in the corrosion performance. These tests revealed sensitization only at the σ phase grain boundaries in the samples treated at 850 °C in electrolytes containing H2SO4 2.5 mol/L and HCl 1 mol/L. Although the treatment at 950 °C led to the σ phase formation, its higher corrosion resistance was ascribed to the lower volumetric fraction of this phase, its morphology, and its increased Cr mobility compared to the 850 °C treatment. Therefore, it was shown that the σ characteristics and the sulfuric acid concentrations are determining factors in the UNS S32205 intergranular corrosion resistance.
Lime Stabilization of Tropical Soil for Resilient Pavements: Mechanical, Microscopic, and Mineralogical Characteristics
Authors: Diniz Bruna Calabria , Fedrigo William , Kleinert Thaís Radünz , Batista Giovanni dos Santos , Núñez Washington Peres , Correa Bethania Machado , Brito Lélio Antônio Teixeira
Published: September 2024

Lime stabilization is a sustainable technique due to its use of local materials, increased durability, reduced maintenance, and improved resistance to water action. This paper examines the impact of lime stabilization on the mechanical, microscopic, and mineralogical properties of a tropical soil. Two types of lime, calcitic and dolomitic, were tested at 3% and 5% by weight. Compressive, indirect tensile and flexural test results and statistical analysis revealed that calcitic lime mixtures had higher strength and stiffness, whereas dolomitic lime mixtures exhibited greater deformability with higher tensile strain at break. Scanning electron microscopy indicated that the soil’s porous matrix closed within 7 days for both lime types due to flocculation, with increased matrix interlocking over time. The calcitic lime mixture developed a more closed matrix compared to the dolomitic lime, which showed weaker cementing. X-ray diffraction analysis indicated higher consumption of clay minerals and a notable reduction in calcium hydroxide peaks in the lime-treated soils. The study concludes that calcitic lime provides better pavement performance for stabilizing the soil, enhancing its engineering properties while also being sustainable by reducing the need for raw material extraction and improving resilience to climate-related issues such as floods.
Study on the Flexural Deformation Behavior of High-Titanium Heavy-Slag Concrete Composite Beams: Material Application, Experimental Investigation, and Theoretical Refinement
Authors: Sun Jinkun , Yu Yun , Li Rita Yi Man , Wang Zilin , Li Lindong , Guo Feifei , Yu Liangliang , Deng Chenxi
Published: September 2024

To investigate the flexural performance of high-titanium heavy-slag concrete composite beams under loading, this study examined the impact of various factors on deflection development and crack propagation as well as the applicability of empirical formulas for monolithic concrete beams. Seven concrete beams were fabricated with variables such as the reinforcement ratio, prefabrication height, and material composition, and were subjected to two-point concentrated loading. By comparing deflection values and crack widths during loading and analyzing the correlations with empirical formulas from standards, theoretical formulas with significant deviations were modified and compared. The study indicated that the cracking moment and deflection correlated with the reinforcement ratio, material structure combination, and composite height. The empirical formulas for the maximum crack width and deflection of flexural members were applicable to high-titanium heavy-slag concrete composite beams, although some discrepancies existed compared with the experimental values. After modifications, these discrepancies were reduced. This research provides a comprehensive analysis of the deformation characteristics and fracture behavior of high-titanium heavy-slag concrete composite beams.
Novel High-Strength and High-Temperature Resistant Composite Material for In-Space Optical Mining Applications: Modeling, Design, and Simulation at the Polymer and Atomic/Molecular Levels
Authors: Sare Hadarou , Dong Dongmei
Published: September 2024

This study explores the modeling, design, simulation, and testing of a new composite material designed for high-strength and high-temperature resistance in in-space optical mining, examining its properties at both the polymer and atomic/molecular levels. At the polymer level, the investigation includes mechanical and thermal performance analyses using COMSOL Multiphysics 6.1, employing layerwise theory, equivalent single layer (ESL) theory, and a multiple-model approach for mechanical modeling, alongside virtual thermal experiments simulating laser heating. Experimentally, porous Polyaniline (PANI) films are fabricated via electrochemical polymerization, with variations in voltage and deposition time, to study their morphology, optical performance, and electrochemical behavior. At the atomic and molecular levels, this study involves modeling the composite material, composed of Nomex, Kevlar, and Spirooxazine-Doped PANI, and simulating its behavior. The significance of this work lies in developing a novel composite material for in-space optical mining, integrating it into optical mining systems, and introducing innovative thermal management solutions, which contribute to future space exploration by improving resource efficiency and sustainability, while also enhancing the understanding of PANI film properties for in-space applications.
Enhancing Capillary Pressure of Porous Aluminum Wicks by Controlling Bi-Porous Structure Using Different-Sized NaCl Space Holders
Authors: Shen Hongfei , Suzuki Asuka , Takata Naoki , Kobashi Makoto
Published: September 2024

Capillary pressure and permeability of porous media are important for heat transfer devices, including loop heat pipes. In general, smaller pore sizes enhance capillary pressure but decrease permeability. Introducing a bi-porous structure is promising for solving this trade-off relation. In this study, the bi-porous aluminum was fabricated by the space holder method using two different-sized NaCl particles (approximately 400 and 40 μm). The capillary pressure and permeability of the bi-porous Al were evaluated and compared with those of mono-porous Al fabricated by the space holder method. Increasing the porosity of the mono-porous Al improved the permeability but reduced the capillary pressure because of better-connected pores and increased effective pore size. The fraction of large and small pores in the bi-porous Al was successfully controlled under a constant porosity of 70%. The capillary pressure of the bi-porous Al with 40% large and 30% small pores was higher than the mono-porous Al with 70% porosity without sacrificing the permeability. However, the bi-porous Al with other fractions of large and small pores did not exhibit properties superior to the mono-porous Al. Thus, accurately controlling the fractions of large and small pores is required to enhance the capillary performance by introducing the bi-porous structure.
Development and Production of a Children’s Upper-Limb Cycling Adapter Using 3D Printing
Authors: Kopová Barbora , Bakeš Martin , Čížek Martin , Horký Adam , Dvořák Josef , Ráž Karel , Chval Zdeněk
Published: September 2024

The research described in this study focuses on the development of an innovative upper-limb adapter for young children aged 1–3 years who have congenital upper-limb defects. The objective was to create a functional and affordable solution that allows children to engage more safely and actively in physical activities such as cycling. The adapter was designed within the DESIGN+ project at the University of West Bohemia in Pilsen in collaboration with the German company Ottobock. The development included a detailed analysis of hand movements during cycling, modelling using CAD software (NX 1888), prototype manufacturing through 3D printing, and subsequent testing. The result is an adapter that allows 360° rotation around the arm axis, provides natural hand movement while turning, and is made of soft material to enhance safety. Despite initial challenges and necessary prototype adjustments, a functional and reliable design was achieved. This adapter will contribute to improving the quality of life for children with upper-limb disabilities, supporting their coordination, strength, and confidence in daily activities.
Magnetomechanical Behaviors of Hard-Magnetic Elastomer Membranes Placed in Uniform Magnetic Field
Authors: Qu Wenchao , Chen Jun , Wang Huiming
Published: September 2024

This paper aims to develop a theoretical model for a viscoelastic hard-magnetic elastomer membrane (HMEM) actuated by pressure and uniform magnetic field. The HMEM is initially a flat, circular film with a fixed boundary. The HMEM undergoes nonlinear large deformations in the transverse direction. The viscoelastic behaviors are characterized by using a rheological model composed of a spring in parallel with a Maxwell unit. The governing equations for magneto-visco-hyperelastic membrane under the axisymmetric large deformation are constructed. The Zeeman energy, which is related to the magnetization of the HMEM and the magnetic flux density, is employed. The governing equations are solved by the shooting method and the improved Euler method. Several numerical examples are implemented by varying the magnitude of the pre-stretch, pressure, and applied magnetic field. Under different magnetic fields, field variables such as latitudinal stress exhibit distinct curves in the radial direction. It is observed that these varying curves intersect at a point. The position of the intersection point is independent of the applied magnetic field and only controlled by pressure and pre-stretch. On the left side of the intersection point, the field variables increase as magnetic field strength increases. However, on the other side, this trend is reversed. During viscoelastic evolution, one can find that the magnetic field can be used to modulate the instability behaviors of the HMEM. These findings may provide valuable insights into the design of the hard-magnetic elastomer membrane structures and actuators.
Methodical Development of a Digital Twin for an Industry Valve
Authors: Koesters Anton , Koetz Florian , Bock Moritz , Fett Michel , Breimann Richard , Kirchner Eckhard
Published: September 2024

This contribution explores the development of a digital twin for industrial valves, with a focus on mitigating the costly consequences of valve malfunctions in large-scale industrial environments. Industrial valves are critical components in fluid and gas control systems where unexpected failures can lead to significant downtime and financial loss. Digital twins as virtual replicas of physical systems offer a promising solution as they enable real-time monitoring and predictive maintenance. This paper looks at the creation of a digital twin for a specific valve type (74BS from SchuF Armaturen und Apparatebau GmbH) and considers key aspects such as model development, sensor integration and IT infrastructure. A test bench is constructed to collect the measured values to support the validation of the digital twin. The integration of sensors and the development of an IT system for data processing are also described in detail. Finally, the technically relevant frequencies are identified in an FFT.
Few-Shot Classification Based on Sparse Dictionary Meta-Learning
Authors: Jiang Zuo , Wang Yuan , Tang Yi
Published: September 2024

In the field of Meta-Learning, traditional methods for addressing few-shot learning problems often rely on leveraging prior knowledge for rapid adaptation. However, when faced with insufficient data, meta-learning models frequently encounter challenges such as overfitting and limited feature extraction capabilities. To overcome these challenges, an innovative meta-learning approach based on Sparse Dictionary and Consistency Learning (SDCL) is proposed. The distinctive feature of SDCL is the integration of sparse representation and consistency regularization, designed to acquire both broadly applicable general knowledge and task-specific meta-knowledge. Through sparse dictionary learning, SDCL constructs compact and efficient models, enabling the accurate transfer of knowledge from the source domain to the target domain, thereby enhancing the effectiveness of knowledge transfer. Simultaneously, consistency regularization generates synthetic data similar to existing samples, expanding the training dataset and alleviating data scarcity issues. The core advantage of SDCL lies in its ability to preserve key features while ensuring stronger generalization and robustness. Experimental results demonstrate that the proposed meta-learning algorithm significantly improves model performance under limited training data conditions, particularly excelling in complex cross-domain tasks. On average, the algorithm improves accuracy by 3%.
Perturbation Approach to Polynomial Root Estimation and Expected Maximum Modulus of Zeros with Uniform Perturbations
Authors: Nafisah Ibrahim A. , Sheikh Sajad A. , Alshahrani Mohammed A. , Almazah Mohammed M. A. , Alnssyan Badr , Dar Javid Gani
Published: September 2024

This paper presents a significant extension of perturbation theory techniques for estimating the roots of polynomials. Building upon foundational results and recent work by Pakdemirli and Yurtsever, as well as taking inspiration from the concept of probabilistic bounds introduced by Sheikh et al., we develop and prove several novel theorems that address a wide range of polynomial structures. These include polynomials with multiple large coefficients, coefficients of different orders, alternating coefficient orders, large linear and constant terms, and exponentially decreasing coefficients. Among the key contributions is a theorem that establishes an upper bound on the expected maximum modulus of the zeros of polynomials with uniformly distributed perturbations in their coefficients. The theorem considers the case where all but the leading coefficient receive a uniformly and independently distributed perturbation in the interval [−1,1]. Our approach provides a comprehensive framework for estimating the order of magnitude of polynomial roots based on the structure and magnitude of their coefficients without the need for explicit root-finding algorithms. The results offer valuable insights into the relationship between coefficient patterns and root behavior, extending the applicability of perturbation-based root estimation to a broader class of polynomials. This work has potential applications in various fields, including random polynomials, control systems design, signal processing, and numerical analysis, where quick and reliable estimation of polynomial roots is crucial. Our findings contribute to the theoretical understanding of polynomial properties and provide practical tools for engineers and scientists dealing with polynomial equations in diverse contexts.
Integrating Fuzzy MCDM Methods and ARDL Approach for Circular Economy Strategy Analysis in Romania
Authors: Delcea Camelia , Nica Ionuț , Georgescu Irina , Chiriță Nora , Ciurea Cristian
Published: September 2024

This study investigates the factors influencing CO2 emissions in Romania from 1990 to 2023 using the Autoregressive Distributed Lag (ARDL) model. Before the ARDL model, we identified a set of six policies that were ranked using Fuzzy Electre, Topsis, DEMATEL, and Vikor. The multi-criteria decision-making (MCDM) methods have highlighted the importance of a circular policy on CO2 emission reduction, which should be a central focus for policymakers. The results of the ARDL model indicate that, in the long term, renewable energy production reduces CO2 emissions, showing a negative relationship. Conversely, an increase in patent applications and urbanization contributes to higher CO2 emissions, reflecting a positive impact. In total, five key factors were analyzed: CO2 emissions per capita, patent applications, gross domestic product, share of energy production from renewables, and urbanization. Notably, GDP does not significantly explain CO2 emissions in the long run, suggesting that economic growth alone is not a direct driver of CO2 emission levels in Romania. This decoupling might result from improvements in energy efficiency, shifts towards less carbon-intensive industries, and the increased adoption of renewable energy sources. Romania has implemented effective environmental regulations and policies that mitigate the impact of economic growth on CO2 emissions.
TPE-Optimized DNN with Attention Mechanism for Prediction of Tower Crane Payload Moving Conditions
Authors: Akber Muhammad Zeshan , Chan Wai-Kit , Lee Hiu-Hung , Anwar Ghazanfar Ali
Published: September 2024

Accurately predicting the payload movement and ensuring efficient control during dynamic tower crane operations are crucial for crane safety, including the ability to predict payload mass within a safe or normal range. This research utilizes deep learning to accurately predict the normal and abnormal payload movement of tower cranes. A scaled-down tower crane prototype with a systematic data acquisition system is built to perform experiments and data collection. The data related to 12 test case scenarios are gathered, and each test case represents a specific combination of hoisting and slewing motion and payload mass to counterweight ratio, defining tower crane operational variations. This comprehensive data is investigated using a novel attention-based deep neural network with Tree-Structured Parzen Estimator optimization (TPE-AttDNN). The proposed TPE-AttDNN achieved a prediction accuracy of 0.95 with a false positive rate of 0.08. These results clearly demonstrate the effectiveness of the proposed model in accurately predicting the tower crane payload moving condition. To ensure a more reliable performance assessment of the proposed AttDNN, we carried out ablation experiments that highlighted the significance of the model’s individual components.