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Reassessment of eddy viscosity turbulence models as alternatives to Reynolds stress models for gas cyclone separator CFD simulations
Abstract Various Reynolds stress turbulence model (RSM) formulations have been widely employed in computational fluid dynamics (CFD) simulations of gas cyclone separators for more than two decades, primarily because they do not rely on the Boussinesq hypothesis (isotropic eddy-viscosity assumption) and can better represent anisotropic turbulence and strongly swirling flows, which simpler eddy-viscosity turbulence models (EVMs) often struggle to capture accurately. But are RSMs truly the only Reynolds-averaged Navier-Stokes (RANS) turbulence models capable of simulating the mean flow in gas cyclone separators? Does their continued popularity result from their actual performance or from modeling bias arising from the Boussinesq (isotropic eddy-viscosity) assumption and the limitations in the discretization approaches (including grid generation and numerical schemes) adopted in previous CFD studies of EVMs? To address these questions, this work compares predictions from several EVMs (Spalart-Allmaras, standard k-epsilon, renormalization group k-epsilon, realizable k-epsilon, standard k-omega, and shear-stress transport k-omega) with and without curvature correction, against those from linear and quadratic pressure-strain RSMs and reference experimental data for a 0.29-m-diameter Stairmand gas cyclone. The results show that appropriate discretization approach enhances the capability of some non-modified EVMs to predict mean velocities in weak-curvature-effect circumstance (e.g., inside the cyclone barrel). Curvature correction improves the mean flow prediction accuracy of EVMs. In addition, caution is advised when applying RANS-predicted root-mean-square velocity fluctuations to describe cyclone flow phenomena. Finally, this study demonstrates that, for the study conditions, the realizable k-epsilon model with curvature correction can provide accuracy comparable to linear and quadratic pressure-strain RSMs in predicting the mean flow in gas cyclone separators while requiring shorter computational time, thereby challenging the long-held preference that RSMs are the only suitable RANS turbulence models for such applications.
Performance evaluation of corroded reinforced concrete columns strengthened with FRCM under cyclic loading and subsequent corrosion rate
Ionic liquid-grafted PVDF membrane incorporated with g-C3N4-Fe3O4 for the removal of cationic dye and improved anti-bacterial activity
Long-Term Survival of Hypoimmune Allogeneic Islets without Immunosuppression
Number comparison in bilinguals is not affected by their second language
Abstract Language background can show subtle effects on number comparison even with Arabic digits. Number pairs can be decade-unit compatible, i.e. the decision about number size is the same for unit and decade (e.g. 24 and 57, 2 < 5 and 4 < 7), or decade-unit incompatible (e.g. 29 and 57, 2 < 5 but 9 > 7). Incompatible pairs often lead to longer response times. This compatibility effect is larger in languages with number word inversion (e.g. German). We aimed to investigate the influence of language on the compatibility effect in bilinguals. In Experiment 1, we compared the compatibility effect in German monolinguals and German-English bilinguals. We found a significant compatibility effect, but no significant differences between the mono- and bilinguals. In Experiment 2, we manipulated language activation within participants by asking German-English bilinguals to describe scenes either in English or German before completing number comparison trials. There was a significant cost of switching languages, showing that participants did activate German and English. However, the size of the compatibility effect was not significantly influenced by participants activating German or English. Overall, we did not find an influence of a bilingual’s language on number comparison with Arabic digits.
Assessment of thermomechanical properties of CFRP laminates reinforced with nano-graphene, with and without phenol addition
Improving wind power prediction performance using the SKB-FA-XGB method based on hybrid feature selection
Adverse and positive childhood experiences and dental pain in adulthood: a cross-sectional study
A higher START red-criteria count at emergency department arrival is associated with increased 28-day mortality in the CRASH-2 trial
Abstract Hemorrhagic shock is a leading cause of preventable trauma death, and early risk stratification is needed before laboratory or imaging results are available. We conducted a secondary analysis of CRASH-2 to evaluate whether a START-derived count of reconstructed Red criteria at emergency department arrival provides prognostic discrimination. Criteria were respiratory rate < 10 or ≥ 30/min, capillary refill time ≥ 2 s, and inability to follow commands (Glasgow Coma Scale motor score < 6). Because ambulation status was unavailable, formal START color categories were not reconstructed. Criteria were counted from 0 to 3, and associations with 28-day mortality and transfusion requirements were examined. Among 18,756 patients, 2,830 died. Mortality increased stepwise with the count. In adjusted Cox models, mortality risk increased progressively, with an adjusted hazard ratio of 12.45 (95% CI 8.33–18.61) for 3 versus 0 criteria. Discrimination was moderate (AUC 0.725, 95% CI 0.716–0.734) and similar after excluding capillary refill time (AUC 0.721), whereas capillary refill time alone performed less well (AUC 0.600). Transfusion requirements also increased with higher counts. In this high-risk cohort, the reconstructed count may provide an early physiologic risk signal before resource-dependent trauma assessments become available.
Effects of metallic debris and environmental factors on negative DC needle–plate air-gap discharge
Deep learning for patient-specific quality assurance of volumetric modulated arc therapy: predicting gamma passing rate based on accelerator dynamic log files
Abstract To predict and classify the gamma passing rate (GPR) for patient-specific quality assurance (PSQA) in VMAT using a deep learning approach based on accelerator dynamic log files. Dynamic log files of 438 VMAT plans were analyzed. GPR were measured by using Delta4. Using dynamic log files as inputs and GPR under five different criteria as outputs, the Resnet-based model was trained by a five-fold cross-validation method. The average absolute error (MAE), mean square error (MSE), root mean square error (RMSE), Spearman’s rank correlation coefficient (Sr), coefficient of determination (R 2 ), and Classification performance were calculated. In the test dataset, the predictive model demonstrated good agreement with measured GPR values across different gamma criteria, with MAE ranging from 0.59 to 2.05%, RMSE ranging from 1.02 to 3.94%, and R 2 ranging from 0.76 to 0.88. Significant correlations were observed between predicted and measured GPR values under all gamma criteria (Sr = 0.83–0.94, p < 0.001).For the classification models, the accuracy ranged from 0.87 to 0.96, while the AUC values ranged from 0.89 to 0.97 across different gamma criteria, indicating favorable classification performance. We developed a deep learning model that demonstrated promising performance in predicting and classifying GPR for VMAT PSQA. The model is promising as it streamlines the PSQA process and may reduces the associated workload, demonstrating substantial clinical potential.
Knowledge, attitudes, and practices of hemorrhoid patients regarding surgical treatment
Abstract This study aimed to assess the knowledge, attitudes, and practices (KAP) of patients with hemorrhoids concerning surgical treatment. This cross-sectional study was conducted between October 2023 and February 2025 in Chengdu, Sichuan Province, China and included patients diagnosed with hemorrhoids. Data were collected through a self-designed structured questionnaire, which included sections on sociodemographic characteristics and evaluated participants’ KAP related to surgical treatment. A total of 431 patients diagnosed with hemorrhoids participated in the study. The mean knowledge, attitude, and practice scores were 8.01 ± 3.07 (possible range: 0–18), 30.61 ± 2.16 (possible range: 7–35), and 34.68 ± 4.73 (possible range: 8–40), respectively. The results of the SEM analysis shown that attitude had a direct effect on practice (β = 0.378, P < 0.001). However, neither the direct effect of knowledge on attitude and practice nor the indirect effect of knowledge on practice was significant. Patients with hemorrhoids exhibited limited knowledge but generally positive attitudes and proactive practices regarding surgical treatment, with attitudes emerging as the primary driver of practice behaviors. These findings suggest that interventions aimed at improving patient outcomes should prioritize attitude-based education strategies, while also addressing knowledge gaps to support informed decision-making.
A single polymer electrolyte incorporating tributyl methyl phosphonium iodide for energy storage and conversion applications
A hybrid fuzzy dissimilarity histogram and automatic fuzzy clustering framework for robust color image segmentation
Elastic wave interaction with a stressed half-space containing voids
Abstract This study explores the reflection characteristics of plane shear vertical (SV) waves incident upon the free surface of an initially stressed, isotropic elastic half-space containing voids. Using Biot’s theory of incremental deformations and the generalized theory of porous elastic media, the governing equations are formulated and analytically solved under two-dimensional plane strain conditions. The presence of initial stress and voids modifies the propagation behavior of elastic waves. It is found that the incident SV-wave gives rise to two distinct reflected waves: a compressional (P) wave and a rotational (SV) wave. The analysis reveals that the reflected SV-wave is influenced solely by the initial stress, whereas the reflected P-wave is significantly affected by both initial stress and the void parameters. Closed-form expressions for the reflection coefficients are derived analytically and evaluated numerically to examine their variations with incident angle, void parameters, and frequency are examined. The results offer insight into wave behavior in porous geological media and stress-loaded materials.