Search Results (534)

This paper presents a novel EEG-based learning system designed to enhance the efficiency and effectiveness of studying by dynamically adjusting the difficulty level of learning materials based on real-time attention levels. In the training phase, EEG signals corresponding to high and low concentration levels are recorded while participants engage in quizzes to learn and memorize Chinese characters. The attention levels are determined based on performance metrics derived from the quiz results. Following extensive preprocessing, the EEG data undergoes severmal feature extraction steps: removal of artifacts due to eye blinks and facial movements, segregation of waves based on their frequencies, similarity indexing with respect to delay, binary thresholding, and (PCA). These extracted features are then fed into a k-NN classifier, which accurately distinguishes between high and low attention brain wave patterns, with the labels derived from the quiz performance indicating high or low attention. During the implementation phase, the system continuously monitors the user’s EEG signals while studying. When low attention levels are detected, the system increases the repetition frequency and reduces the difficulty of the flashcards to refocus the user’s attention. Conversely, when high concentration levels are identified, the system escalates the difficulty level of the flashcards to maximize the learning challenge. This adaptive approach ensures a more effective learning experience by maintaining optimal cognitive engagement, resulting in improved learning rates, reduced stress, and increased overall learning efficiency. This adaptive approach ensures a more effective learning experience by maintaining optimal cognitive engagement, resulting in improved learning rates, reduced stress, and increased overall learning efficiency. Our results indicate that this EEG-based adaptive learning system holds significant potential for personalized education, fostering better retention and understanding of Chinese characters. Full article

Background/Objectives: Speech perception typically takes place against a background of other speech or noise. The present study investigates the effectiveness of segregating speech streams within a competing speech signal, examining whether cues such as pitch, which typically denote a difference in talker, behave in the same way as cues such as speaking rate, which typically do not denote the presence of a new talker. Methods: Native English speakers listened to English target speech within English two-talker babble of a similar or different pitch and/or a similar or different speaking rate to identify whether mismatched properties between target speech and masker babble improve speech segregation. Additionally, Dutch and French masker babble was tested to identify whether an unknown language masker improves speech segregation capacity and whether the rhythm patterns of the unknown language modulate the improvement. Results: Results indicated that a difference in pitch or speaking rate between target and masker improved speech segregation, but when both pitch and speaking rate differed, only a difference in pitch improved speech segregation. Results also indicated improved speech segregation for an unknown language masker, with little to no role of rhythm pattern of the unknown language. Conclusions: This study increases the understanding of speech perception in a noisy ecologically valid context and suggests that there is a link between a cue’s potential to denote a new speaker and its ability to aid in speech segregation during competing speech perception. Full article

High-titanium steel contains an elevated titanium content, which promotes the formation of abundant non-metallic inclusions in molten steel at high temperatures, including titanium oxides, sulfides, and nitrides. These inclusions adversely affect continuous casting operations and generate substantial internal/surface defects in cast slabs, ultimately compromising product performance and service reliability. Therefore, stringent control over the size, distribution, and population density of inclusions is imperative during the smelting of high-titanium steel to minimize their detrimental effects. In this paper, samples of high titanium steel (0.4% Ti, 0.004% N) casting billets were analyzed by industrial test sampling and full section comparative analysis of the samples at the center and quarter position. Using the Particle X inclusions, as well as automatic scanning and analyzing equipment, the number, size, location distribution, type and morphology of inclusions in different positions were systematically and comprehensively investigated. The results revealed that the primary inclusions in the steel consisted of TiN, TiS, TiC and their composite forms. TiN inclusions exhibited a size range of 1–5 µm on the slab surface, while larger particles of 2–10 μm were predominantly observed in the interior regions. Large-sized TiN inclusions (5–10 μm) are particularly detrimental, and this problematic type of inclusion predominantly concentrates in the interior regions of the steel slab. A gradual decrease in TiN inclusion number density was identified from the surface toward the core of the slab. Thermodynamic and kinetic calculations incorporating solute segregation effects demonstrated that TiN precipitates primarily in the liquid phase. The computational results showed excellent agreement with experimental data regarding the relationship between TiN size and solidification rate under different cooling conditions, confirming that increased cooling rates lead to reduced TiN particle sizes. Both enhanced cooling rates and reduced titanium content were found to effectively delay TiN precipitation, thereby suppressing the formation of large-sized TiN inclusions in high-titanium steels. Full article

This study presents the design and microstructural investigation of a single-crystal (SX) Re-bearing high-entropy superalloy (HESA-X1) featuring a thermally stable γ–γ′–γ hierarchical microstructure. The alloy exhibits FCC γ nanoparticles embedded within L1₂-ordered γ′ precipitates, themselves distributed in a γ matrix, with the suppression of detrimental topologically close-packed (TCP) phases. To elucidate solidification behavior and phase stability, Scheil–Gulliver and TC-PRISMA simulations were conducted alongside SEM and XRD analyses. Near-atomic scale analysis in 3D using Atom Probe Tomography (APT) revealed pronounced elemental partitioning, with Re strongly segregating to the γ matrix, while Al and Ti were preferentially enriched in the γ′ phase. Notably, Re demonstrated a unique partitioning behavior compared to conventional superalloys, facilitating the formation and stabilization of γ nanoparticles during two-step aging (Ag-2). These γ nanoparticles significantly contribute to improved mechanical properties. Long-term aging (up to 200 h) at 750–850 °C confirmed exceptional phase stability, with minimal coarsening of γ′ and retention of γ nanoparticles. The coarsening rate constant K of γ′ at 750 °C was significantly lower than that of Re-free HESA, confirming the diffusion-suppressing effect of Re. These findings highlight critical roles of Re in enhancing microstructural stability by reducing atomic mobility, enabling the development of next-generation HESAs with superior thermal and mechanical properties for high-temperature applications. Full article

Waste cooking oil (WCO) plays different roles in modified asphalt and significantly affects the performance of the binder. However, a systematic comparative study is still lacking in the existing research. This study investigates the effects of WCO used as a swelling agent for rubber powder (RP) and as a compatibilizer in rubber powder-modified asphalt (RPMA) on the performance of modified asphalt. Specifically, the microstructure and functional groups of WCO-coated RP were first characterized. Then, RPMAs with different RP dosages were prepared, and the storage stability and rheological properties of RPMAs were thoroughly investigated. Finally, the flue gas emission characteristics of different RPMAs at 30% RP dosing were further analyzed, and the corresponding inhibition mechanisms were proposed. The results showed that the RP coated by WCO was fully solubilized internally, and the WCO formed a uniform and continuous coating film on the RP surface. Comparative analysis revealed that when WCO was used as a swelling agent, the prepared S-RPMA exhibited superior storage stability. At a 30% RP content, the softening point difference value of S-RPMA was only 1.8 °C, and the reduction rate of the segregation index reached 40.91%. Surprisingly, after WCO was used to coat the RP, the average concentrations of VOCs and H₂S in S-RPMA30 were reduced to 146.7 mg/m³ and 10.6 ppm, respectively, representing decreases of 20.8% and 22.1% compared with the original RPMA30. These findings demonstrate that using WCO as a swelling agent enhances both the physical stability and environmental performance of RPMA, offering valuable insights for the rational application and optimization of WCO incorporation methods in asphalt modification. It also makes meaningful contributions to the fields of coating science and sustainable materials engineering. Full article

Children’s safety, well-being and inclusion in the school environment can be severely impacted by social isolation and bullying. This study examined these threats in a sample of 14 group-classes (291 students) from four different primary education schools. A total of 44 special educational needs (SEN) students and 44 students without SEN were selected. The social network structure of each group-class was analysed, as well as the number of friendship ties, the degree of emotional well-being and social participation (both inside and outside of the school), and the possible cases of bullying. The results show a significantly greater rate of social rejection, emotional distress and risk of exclusion in SEN students with respect to their peers, as well as a considerably higher perception of bullying (38.6% vs. 4.8%). The SEN students who reported bullying were mostly schooled in social networks with a more segregated and fragmented structure. Moreover, the mean value obtained in these groups was lower for all the analysed indicators, although the differences were not statistically significant. These data support the idea that the social capital of the group class could influence the prevention of violence and bullying towards SEN students. However, further studies with larger samples are needed to confirm this. Lastly, strategies to promote the social inclusion of SEN students in primary education schools are discussed. Full article

This study investigated how long-term aging (750 °C and 950 °C) affects the microstructure and room-temperature tensile properties of the Ni-Co-Cr superalloy GH3617. Characterization (SEM, EDS, EBSD) showed that initial aging (750 °C, 500 h) formed discontinuous M₂₃C₆ carbides, pinning grain boundaries and improving strength. Prolonged aging (750 °C, 5000 h) caused M₂₃C₆ to coarsen into brittle chain-like structures (width up to 1.244 μm) and precipitated M₆C carbides, degrading grain boundaries. Aging at 950 °C accelerated this coarsening via LSW kinetics (rate constant: 6.83 × 10⁻² μm³/s), with Mo segregation promoting M₆C formation. Tensile properties resulted from competing γ′ precipitation strengthening (post-aging strength increased up to 23.3%) and grain boundary degradation (elongation dropped from 70.1% to 43.3%). Fracture shifted from purely intergranular (cracks along M₂₃C₆/γ interfaces at 750 °C) to mixed mode (cracks initiated by M₆C fragmentation at 950 °C). These insights support superalloy microstructure optimization and lifetime prediction. Full article

Cu-5wt%TiC coatings were fabricated by high-speed laser cladding on the 7075 aluminum alloy substrate using various scanning speeds to improve its current-carrying wear resistance. The effects of scanning speed on the microstructure, phase, hardness, and current-carrying tribological properties of the coating were investigated using a scanning electron microscope, an X-ray diffractometer, a hardness tester, and a wear tester, respectively. The results show that the increase in scanning speed accelerates the coating’s solidification rate. Among the samples, the coating comprised of equiaxed crystals prepared at 149.7 mm/s presents the best quality, but solidification speeds that are too rapid lead to elemental segregation. The hardness of the coating also decreases with the increase in scanning speed. The coating prepared at 149.7 mm/s exhibits the best wear resistance and electrical conductivity. The wear rate of the coating prepared at 149.7 mm/s at 25 A was 4 × 10⁻³ mg·m⁻¹, respectively. During the current-carrying friction process, the presence of thermal effects and arc erosion cause the worn track to be prone to oxidation, adhesion, and plastic deformation, so the current-carrying wear mechanisms of coatings at 25 A include adhesive wear, oxidation wear, and electrical damage. Full article

This study aimed to determine the thermoneutral zone (TNZ) in Sahiwal zebu calves under controlled environmental conditions. The experiment was conducted in the psychrometric chamber in two phases on six calves aged 8 to 11 months and weighing 120 to 150 Kg at the beginning of the experiment. In the first phase, to determine the upper critical temperature (UCT), calves were kept for six hours per day over 10 consecutive days at six different increasing temperature ranges from 24 to 39 °C with corresponding temperature humidity indexes (THIs) between 67 and 93. In the second phase, the same calves were exposed to decreasing temperatures (24 °C to 9 °C) to determine the lower critical temperature (LCT). On the 10th day of each temperature exposure, physiological parameters were recorded, and blood sampling was done. Using segmented regression analysis (SegReg standard version software), the breakpoints in linear regressions for different parameters with respect to exposure temperatures and THI in both phases were separately determined and considered to be the critical temperatures and threshold THIs, respectively. The LCT and UCT were arranged on a temperature scale. The temperature range between the highest LCT and the lowest UCT with respect to different studied parameters was considered as the thermoneutral zone (TNZ). The highest LCT was observed for granulocyte % at 18.15 °C, whereas the lowest UCT was observed at 30.10 °C (THI: 82.35). It was found that the LCT and UCT varied with respect to different physiological parameters. A subset of parameters displayed identifiable LCT and UCT values, while some did not exhibit clear breakpoints. The respiration rate (RR), rectal temperature (RT), total leukocyte count (TLC), granulocyte%, aspartate amino-transferase (AST), Alanine amino-transferase (ALT), cortisol, IL6, and HSP90 were the sensitive parameters for both cold stress and heat stress, whereas pulse rate (PR), triglyceride, and urea were only sensitive to cold stress, and erythrocytic parameters and lymphocyte % were sensitive only to heat stress. Based on heat stress responses, the UCT for zebu calves was identified at approximately 30.10 °C (THI: 82.35), whereas based on cold stress responses, the LCT for zebu calves was identified at approximately 18.15 °C. Thus, the TNZ for zebu calves can be proposed to be between 18.15 and 30.10 °C. These findings can inform climate-adaptive housing and management strategies for improving calf welfare and productivity in subtropical environments. Full article

Background: Telomerase activity is a cancer hallmark, and hTERT is the rate-limiting catalytic subunit of telomerase. In human papillomavirus type 16 E6 (16E6)-expressing epithelial cells, NFX1-123 augments and is required for full hTERT expression, leading to a growth advantage. However, no studies have investigated the role of NFX1-123 in telomerase activity regulation in HPV-associated cancers. Methods: We knocked out NFX1-123 in CaSki cells (CaSki KO) and performed single-cell RNA sequencing to determine mRNA alterations affected by reduced NFX1-123. Results: In CaSki KO cells, there were three cell clusters based on gene expression, each associated with different enriched biological processes. When pooled and compared with control cells, CaSki KO cells had 1661 decreased and 565 increased mRNAs involving RNA regulation, cell cycle and division, chromatin regulation, and carcinogenesis processes and pathways. CENP-F, a cell cycle and chromosome segregation gene increased in cervical cancers, was among 10 genes with the greatest decrease in mRNA expression in CaSki KO cells. CaSki and SiHa cells with either reduced NFX1-123 or knocked down HPV 16 E6 and E7, demonstrated reduced hTERT, CENP-F, and telomerase activity, and when both NFX1-123 and HPV 16 E6 and E7 were decreased, hTERT and telomerase activity fell further. Finally, hTERT and CENP-F were increased in cervical cancer primary tumors and in HPV-positive head and neck cancer primary tumors in the TCGA database. Conclusions: These findings highlight the shared role that NFX1-123 has with HPV 16 oncogenes in driving and maintaining RNA, cell cycle, and carcinogenesis pathways, and specifically regulating hTERT, telomerase, and CENP-F. Full article

Meiotic recombination is essential for chromosomal segregation and facilitates the exchange between homologs, which leads to the transmission of new combinations of linked alleles to the progeny. The eukaryotic meiotic machinery is generally highly conserved, but the frequency of crossover occurrence can vary dramatically across species and populations, between individuals, and across sexes. The chicken and the guinea fowl exhibit interspecific variation in the distribution of crossovers along their largest chromosomes. In many organisms, an association has been observed between the preferred crossover location and certain sequence parameters, such as high GC content, CpG islands, or gene promoters. Here, we compared the distribution of these genomic parameters with the recombination landscape, represented by MLH1 focus frequencies, in the two birds. We found an association between GC content density and recombination in the chicken, but the remaining parameters showed weak or no association with recombination, especially in the guinea fowl. We conclude that despite the different broad-scale crossover distribution, the investigated genomic parameters remained remarkably similar in these two species. We suggest that the density of these genomic features is more likely related to microscale variations in recombination rates, such as those determined by open chromatin configurations. Full article

Objective: Low birth weight is a serious public health problem even in developed countries. The objective of this study was to assess the ability of machine learning to predict low birth weight rates in big cities in the USA on an ecological/population level. Study design: The study was based on publicly available data from the Big Cities Health Inventory Data Platform. The collected data related to the 35 largest, most urban cities in the United States from 2010 to 2022. The model-agnostic approach was used to assess and visualize the magnitude and direction of the most influential predictors. Results: The models showed excellent performance with R-squared values of 0.82, 0.81, 0.81, and 0.79, and residual root mean squared error values of 1.06, 0.87, 1.03, 0.99 for KNN, Best subset, Lasso, and XGBoost, respectively. It is noteworthy that the Best subset selection approach had a high RSq and the lowest residual root mean squared error, with only a four-predictor subset. Influential predictors that appeared in three/four models were rate of chlamydia infection, racial segregation, prenatal care, percentage of single-parent families, and poverty. Other important predictors were the rate of violent crimes, life expectancy, mental distress, income inequality, hazardous air quality, prevalence of hypertension, percent of foreign-born citizens, and smoking. This study was limited by the unavailability of data on gestational age. Conclusions: The machine learning algorithms showed excellent performance for the prediction of low birth weight rate in big cities. The identification of influential predictors can help local and state authorities and health policy decision makers to more effectively tackle this important health problem. Full article

The municipal solid waste generation is projected to spike from 2.1 billion tonnes in 2023 to 3.8 billion tonnes by 2050. In Taiwan, the upsurge of waste volume, in addition to periodic maintenance of incinerators, which may persist up to four months, has resulted in limited incineration capacity. The optimum approach to address the challenge is to reduce the amount of waste sent for incineration by effective segregation of combustible and non-combustible waste, as well as improving the public recycling rate. Local authorities play a significant role in encouraging public recycling and restricting non-burnable waste from being delivered to incinerators within a short period of time. This can greatly reduce the amount of waste and incinerator maintenance costs. This study aimed to explore the key driving factors for public participation in waste recycling and translate the determinants into policy in order to increase the waste recycling rate. The study employed literature analysis to select factors repeatedly mentioned as indicators and conducted online surveys to collect data on factors influencing consumer engagement in waste recycling in Taiwan. This study also adopted the Analytic Hierarchy Process and established a hierarchical framework with four dimensions (Psychological, Knowledge, Policy, and Infrastructure) and thirteen indicators. The findings have demonstrated that infrastructure (0.275) is the most influential aspect in affecting consumers’ recycling actions, followed by psychological (0.256) and policy aspects (0.251), and knowledge aspect (0.218) as the least influential factor. Positive rewards (0.120), recycling knowledge (0.118), and well-built infrastructure (0.113) were specifically identified as key drivers in encouraging recycling. The findings informed the public’s priorities in recycling involvement, and strategic initiatives targeted at these preferences can effectively assist local authorities in promoting citizen engagement in recycling. Policies that meet public demands, such as positive rewards for recycling, dissemination of recycling knowledge, and provision and improvement of more recycling infrastructure, can ensure the success of the policy implementation and serve as a reference for other Asian countries in reducing waste and improving the recycling rate. Full article

The leaf plastochron serves as an indicator of the rate of leaf appearance, biomass accumulation, and branch number, while also impacting plant architecture and seed yield. However, research on the leaf plastochron of crops remains limited. In this study, 2116C exhibited a rapid leaf plastochron compared to ZH18 during both rosette and bud periods. There were significant positive correlations among the leaf plastochron and primary branch number of the F₂ populations (r ranging from 0.395 to 0.635, p < 0.01). Genetic analyses over two years demonstrated that two equally dominant genes might govern the leaf plastochron. Through bulk segregant analysis sequencing (BSA-seq), three novel genomic intervals were identified on chromosomes A02 (9.04–9.48 Mb and 13.52–13.66 Mb) and A04 (19.84–20.14 Mb) of ZS11 and Darmor-bzh reference genomes. By gene functional annotations, single-nucleotide variation (SNV) analyses, transcriptome data from parents, genetic progeny, and natural accessions, we identified ten candidate genes within the intervals, including FLOWERING LOCUS T, RGL1, MYB-like, CYP96A8, BLH3, NIT2, ASK6, and three CLAVATA3/ESR (CLE)-related genes. These findings lay the molecular foundation for further exploration into the leaf plastochron and the implications in plastochron-related breeding in rapeseed. Full article

Tungsten–diamond metal matrix composites (MMCs) fabricated via L-PBF show potential for applications in nuclear facility shielding, heat sinks, precision cutting/grinding tools, and aerospace hot-end components. In this paper, tungsten (W), diamond (D), and diamond with Ni coating (D-Ni) powders are used to fabricate W+D and W+(D-Ni) composites by L-PBF technology. The results show that at the interface of the W+D sample, the W powder melts while the D powder remains in a solid state during L-PBF processing, and W and C elements gradually diffuse into each other. Due to the high cooling rate of L-PBF processing, the C phase forms a diamond-like carbon (DLC) phase with an amorphous structure, and the W phase becomes a supersaturated solid solution of the C element. At the interface of the W+(D-Ni) sample, the diffusion capacity of Ni and W elements in the solid state is weaker than in the molten state. C and W elements diffuse into the Ni melt, forming a rich Ni area of the DLC phase, while Ni and W elements diffuse into the solid D powder, forming a lean Ni area of the DLC phase. In the rich Ni area of the DLC phase, Ni segregation leads to the precipitation of nanocrystals (several hundred nanometers), whereas in the lean Ni area of the DLC phase, the diffusion capacity of Ni and W elements in the solid D powder is limited, resulting in nanocrystalline sizes of only about tens of nanometers. During W dendrite growth, the addition of the Ni coating and the expelling of the C phenomenon leads to W grain refinement at the interface, which reduces the number and length of cracks in the W+(D-Ni) sample. This paper contributes to the theoretical development and engineering applications of tungsten–diamond MMCs fabricated by L-PBF. Full article