bluuebunny/crossref_metadata_2025 huggingface dataset:
Epiphytic, Attached, and Internal Escherichia coliO157:H7 Subpopulations Associating With Romaine Lettuce Are Strain‐Dependent and Affected by Relative Humidity and Pre‐ and Postharvest Plant State
Authors: Hudson Claire L. , Micallef Shirley A.
Published: October 2024

Romaine lettuce is susceptible to Escherichia coli O157:H7 contamination. We evaluated strain and pre‐ and postharvest lettuce product differences in E. coli O157:H7 subpopulation distribution on romaine lettuce at two relative humidity (RH) levels. Plants of romaine lettuce cultivar 'Carlsbad' harvested and processed 'Carlsbad' leaves, and store‐bought ready‐to‐eat romaine lettuce were inoculated with E. coli O157:H7 reference strain EDL933 and romaine lettuce outbreak strain 2705C. Using four processing methods, we determined pathogen cell fractions representing All (entire population), Epiphytic (loosely attached cells), Strongly Attached + Internal (excluding loosely attached cells), and Internal (excluding epiphytic cells) subpopulations. Preharvest, 80% RH favored subpopulations in each cell fraction, compared to 40% RH (p < 0.01 for both strains) and yielded 92%–100% internalization incidence of E. coli O157:H7, compared to 50%–57% at 40% RH. Levels of internal EDL933 cells were also 1.1 log higher than 2705C cells from plants kept at 80% RH (p < 0.001). While EDL933 had lower measures of Strongly Attached + Internal cells compared to All and Epiphytic fractions (p < 0.01), 2705C yielded no difference. Taken together, data suggest that the lettuce outbreak strain had a higher propensity for strong attachment to leaves and EDL933 internalized more successfully. Moreover, the Strongly Attached + Internal fractions of both strains were lower on preharvest 'Carlsbad' compared to 'Carlsbad' processed leaves (p < 0.01), suggesting that E. coli O157:H7 attached less strongly to preharvest plants than postharvest cut and stored leaves of the same variety. Our study uncovers important factors influencing cultivar‐ and strain‐specific differences in association and internalization of enteric pathogens on leafy greens.
Gastric neoplasm detection of computer‐aided detection‐assisted esophagogastroduodenoscopy changes with implement scenarios: a real‐world study
Authors: Huang Li , Xu Ming , Li Yanxia , Dong Zehua , Lin Jiejun , Wang Wen , Wu Lianlian , Yu Honggang
Published: October 2024

Background and Aim

The implementation of computer‐aided detection (CAD) devices in esophagogastroduodenoscopy (EGD) could autonomously identify gastric precancerous lesions and neoplasms and reduce the miss rate of gastric neoplasms in prospective trials. However, there is still insufficient evidence of their use in real‐life clinical practice.

Methods

A real‐world, two‐center study was conducted at Wenzhou Central Hospital (WCH) and Renmin Hospital of Wuhan University (RHWU). High biopsy rate and low biopsy rate strategies were adopted, and CAD devices were applied in 2019 and 2021 at WCH and RHWU, respectively. We compared differences in gastric precancerous and neoplasm detection of EGD before and after the use of CAD devices in the first half of the year.

Results

A total of 33 885 patients were included and 32 886 patients were ultimately analyzed. In WCH of which biopsy rate >95%, with the implementation of CAD, more the number of early gastric cancer divided by all gastric neoplasm (EGC/GN) (0.35% vs 0.59%, P = 0.028, OR [95% CI] = 1.65 [1.0–2.60]) was found, while gastric neoplasm detection rate (1.39% vs 1.36%, P = 0.897, OR [95% CI] = 0.98 [0.76–1.26]) remained stable. In RHWU of which biopsy rate <20%, the gastric neoplasm detection rate (1.78% vs 3.23%, P < 0.001, OR [95% CI] = 1.84 [1.33–2.54]) nearly doubled after the implementation of CAD, while there was no significant change in the EGC/GN.

Conclusion

The application of CAD devices devoted to distinct increases in gastric neoplasm detection according to different biopsy strategies, which implied that CAD devices demonstrated assistance on gastric neoplasm detection while varied effectiveness according to different implementation scenarios.
Predicting High‐Flow Nasal Cannula Oxygen Therapy Failure in Patients With Acute Hypoxaemic Respiratory Failure Using Machine Learning: Model Development and External Validation
Authors: Cheng Hongtao , Wang Zichen , Feng Mei , Tang Yonglan , Zheng Xiaoyu , Zhang Xiaoshen , Lyu Jun
Published: October 2024

Aims and Objectives

To develop and validate a prediction model for high‐flow nasal cannula (HFNC) failure in patients with acute hypoxaemic respiratory failure (AHRF).

Background

AHRF accounts for a major proportion of intensive care unit (ICU) admissions and is associated with high mortality. HFNC is a non‐invasive respiratory support technique that can improve patient oxygenation. However, HFNC failure, defined as the need for escalation to invasive mechanical ventilation, can lead to delayed intubation, prolonged mechanical ventilation and increased risk of mortality. Timely and accurate prediction of HFNC failure has important clinical implications. Machine learning (ML) can improve clinical prediction.

Design

Multicentre observational study.

Methods

This study analysed 581 patients from an academic medical centre in Boston and 180 patients from Guangzhou, China treated with HFNC for AHRF. The Boston dataset was randomly divided into a training set (90%, n = 522) and an internal validation set (10%, n = 59), and the model was externally validated using the Guangzhou dataset (n = 180). A random forest (RF)‐based feature selection method was used to identify predictive factors. Nine machine learning algorithms were selected to build the predictive model. The area under the receiver operating characteristic curve (AUC) and performance evaluation parameters were used to evaluate the models.

Results

The final model included 38 features selected using the RF method, with additional input from clinical specialists. Models based on ensemble learning outperformed other models (internal validation AUC: 0.83; external validation AUC: 0.75). Important predictors of HFNC failure include Glasgow Coma Scale scores and Sequential Organ Failure Assessment scores, albumin levels measured during HFNC treatment, ROX index at ICU admission and sepsis.

Conclusions

This study developed an interpretable ML model that accurately predicts the risk of HFNC failure in patients with AHRF.

Relevance to Clinical Practice

Clinicians and nurses can use ML models for early risk assessment and decision support in AHRF patients receiving HFNC.

Reporting Method

TRIPOD checklist for prediction model studies was followed in this study.

Patient or Public Contribution

Patients were involved in the sample of the study.
Effect of build orientation on the fabrication trueness of additively manufactured implant‐supported complete arch interim fixed prostheses
Authors: Nejat Amir H. , Güven Mehmet Esad , Çakmak Gülce , Yilmaz Burak , Donmez Mustafa Borga
Published: October 2024

Purpose

To evaluate how build orientation affects the fabrication trueness of additively manufactured implant‐supported complete arch prostheses by comparing them to subtractively manufactured high‐impact polymer‐based prostheses.

Materials and Methods

An edentulous maxillary model with four implants at canine and first molar regions bilaterally was digitized (ATOS Core 80 5MP) to design a reference implant‐supported complete arch prosthesis standard tessellation language file (RF‐STL). The STL file was used to manufacture prostheses additively in five different orientations according to the build platform (AM‐0, 0‐degree; AM‐15, 15‐degree; AM‐30, 30‐degree; AM‐45, 45‐degree; AM‐90, 90‐degree) or subtractively (SM‐HIP, control) (n = 10). The prostheses were digitized with an intraoral scanner (Trios 3) to generate their STLs (TF‐STL). After superimposing TF‐STLs over the RF‐STL with a metrology‐grade analysis software program (Geomagic Control X), surface deviations at four regions (overall, occlusal, overall without occlusal, and abutments), linear deviations at each abutment site, and interimplant distance deviations (canine‐to‐molar, canine‐to‐canine, and molar‐to‐molar) were calculated. One‐way analysis of variance and Tukey HSD tests were used for the statistical analyses (α = 0.05).

Results

AM‐90 mostly had the highest surface deviations, while AM‐0 had the lowest overall, and lowest overall without occlusal region deviations (p ≤ 0.022). SM‐HIP had the lowest occlusal region deviations (p < 0.001). AM‐90 had the highest linear deviations (p < 0.001). AM‐15 had higher canine‐to‐molar deviations than SM‐HIP (p = 0.042). SM‐HIP had the highest canine‐to‐canine deviations, while AM‐90 had higher deviations than AM‐0 and AM‐30 (p ≤ 0.026). AM‐45 and AM‐90 had the highest and AM‐0 had the lowest molar‐to‐molar deviations (p ≤ 0.013).

Conclusions

AM‐0 mostly had higher trueness and AM‐90 mostly had lower trueness within tested outcomes. Additively manufactured prostheses mostly had lower canine‐to‐molar distances and higher molar‐to‐molar distances, whereas SM‐HIP prostheses consistently had higher distances than the design file.
A Meta‐Analytic Review of Personality and Teacher–Student Relationships
Authors: Mammadov Sakhavat , Avci Ayse Hilal
Published: October 2024

Objective

This meta‐analysis provides the first comprehensive synthesis of associations between student and teacher personality traits and the quality of teacher–student relationships.

Method

Fifty‐five studies met the eligibility criteria, contributing a total of 238 effect sizes. We used multivariate meta‐analysis with robust variance estimation (RVE) to model the dependency of effect sizes.

Results

Student prosocial behavior (ρ = 0.59) and proactive personality (ρ = 0.48) were the strongest predictors of positive teacher–student relationship quality. All Big Five traits of students, except neuroticism, showed significant positive associations, with all correlations exceeding 0.4 when holding constant with all other moderators. Teacher agreeableness (ρ = 0.31) and conscientiousness (ρ = 0.29) yielded modest associations. Students with less emotional stability or aggressive behaviors were more likely to experience negative teacher–student relationships, such as conflict and dependency.

Conclusion

Our findings highlight the critical role of student personality in explaining the quality of teacher–student interactions. Multiple traits appear equally important, as indicated by comparable effect sizes. The literature is relatively limited when it comes to teacher personality. We were unable to examine teacher traits in relation to teacher–student conflict and dependency, but, overall, agreeable and conscientious teacher behaviors appeared to be important for favorable interactions, whereas teacher neuroticism may undermine the quality of such interactions.
A note on Johansen's rank conditions and the Jordan form of a matrix
Authors: Franchi Massimo
Published: October 2024

This note presents insights on the Jordan structure of a matrix which are derived from an extension of the and conditions in Johansen (1996). It is first observed that these conditions not only characterize, as it is well known, the size (1 or 2) of the largest Jordan block in the Jordan form of the companion matrix but more generally the geometric multiplicities, the algebraic multiplicities and the whole Jordan structure for eigenvalues of index 1 or 2. In the context of the Granger representation theorem, this means that the Johansen rank conditions do more than determine the order of integration of the process. It is then shown that an extension of these conditions leads to the characterization of the Jordan structure of any matrix.
Chinese Weaponry in Contemporary Middle Eastern Conflicts
Authors: Jia Yingliang , Parto Amin , Dadparvar Shabnam
Published: October 2024

This article examines the role of Chinese armaments in recent Middle Eastern conflicts, showing that although their use has increased over the past decade, they remain less numerous or significant compared to those from the United States and Russia. Chinese‐made weapons have been used in conflicts in Gaza, Syria, Yemen, Libya, and Lebanon due to affordability, streamlined procurement processes, and improved quality. China's critics have alleged that it has played a negative role in these conflicts through proliferation, claims that Beijing has consistently denied. This research investigates the accuracy of these charges and assesses whether China's role should be considered prominent. The study examines weapons that have been used in five ongoing regional conflicts, including the Gaza war. It finds that, unlike Washington and Moscow, which have deliberately transferred military equipment to the region, China has avoided intentionally directing armaments to Middle Eastern conflict zones. Instead, Chinese arms have been redistributed by third parties. The analysis concludes that China's strategy of balancing its relationships across states in conflict has limited the amount of its weapons in the region and kept the impact of those armaments to a minimum.
Development of the compliance with mechanical ventilator scale in: A validity and reliability study
Authors: Pazar Berrin , Savas Hafize , Turgut Sadık , Dal Hayriye Cankar
Published: October 2024

Background

Mechanical ventilation is a widely used treatment modality in cardiac surgery intensive care units (ICUs), especially for patients requiring respiratory support during postoperative management.

Aim

The aim of this study was to define the process of developing a scale to assess adherence to mechanical ventilation in cardiac surgery patients and to assess the validity and reliability of the scale.

Study design

This is a scale development and scale validation study. The study was conducted with 222 patients between April and September 2023. In the first stage, face‐to‐face interviews were conducted with seven nurses. Based on the literature review and content analysis of the interviews, the researchers created an item pool. In the second stage, the validity and reliability of the Mechanical Ventilator Compliance Scale in cardiac surgery patients were assessed. The scale was developed to be used by nurses working in cardiac surgery ICUs.

Results

The first 36‐item scale was subjected to content validity assessment by 14 experts. It was revised according to the experts' feedback and a content validity criterion of 0.83 was obtained. Confirmatory factor analysis showed good fit values for the scale (χ2/SD = 3.09, GFI = 0.90, AGFI = 0.90, CFI = 0.91, RMSEA = 0.06, and RMR = 0.07). Test‐retest analysis to assess the reliability of the scale showed good agreement between responses over time (ICC: 0.932; p < .001). Cronbach's alpha values for the scale and its subscales, behavioural and physical responses were 0.956, 0.949 and 0.912, respectively.

Conclusions

The study findings indicate that the scale is a reliable and valid tool for assessing mechanical ventilator compliance in cardiac surgery patients.

Relevance for Clinical Practice

This study provides nurses in cardiac surgery intensive care units with a measurement tool to objectively assess patients' compliance with mechanical ventilation therapy. The scale provides more reliable results by preventing subjective judgement and estimation in patient assessment.
Assessment of conservation status of Ferula huber‐morathii: association with population genetic structure and regional climate
Authors: Keser Ali Murat , Demir İbrahim
Published: October 2024

Ferula huber‐morathii is an endemic and medicinally important plant. This species is distributed in eight Turkish localities, including three newly identified ones. Its extent of occurrence and area of occupancy is determined to be 3963 km2 and 32 km2 respectively. All localities are characterized by East Mediterranean and sub‐Mediterranean precipitation regimes; however, temperatures increase excessively and precipitation decreases during the flowering period of the species. The population sizes are quite small, and the number of reproducing individuals in some populations is below ten. Analyses of ISSR markers showed the percentage of polymorphic loci to be 94% at the species level and 56% at the population level. The level of genetic differentiation (measured by GST) was 0.37 and the estimated level of gene flow among populations (NM) was 0.84. The percentage of variance occurring within and among populations, determined by AMOVA, was 75% and 25%, respectively. STRUCTURE analysis revealed two genetic clusters of individuals with a geographic structure, similar to that found in UPGMA and an ordination analysis. Some populations turned out to have both low numbers of individuals and low genetic diversity. Since many of the populations are subject to anthropogenic disturbance, the species should remain in the EN category. At the same time, it is suggested that a new in‐situ conservation area should be created around nearby dams, situated in the same climate area as the currently known populations.
Microstructures and properties of AlZnMgCu alloys refined by nano Al3Ti‐TiB2‐AlN‐TiN/Al inoculant ribbons
Authors: Wang Qian , Li Fanfan , Cui Chunxiang , Wu Dayong , Ma Haikun , Kang Jie , Dong Huicong , Su Ru
Published: October 2024

Nano Al3Ti‐TiB2‐AlN‐TiN/Al inoculant ribbons containing a large number of evenly distributed nanoparticles, such as Al3Ti (sized about 300 nm), TiB2 (sized about 100 nm), AlN (sized about 150 nm), and TiN (sized about 200 nm), were prepared by vacuum rapid quenching furnace to refine AlZnMgCu alloys. The nano Al3Ti‐TiB2‐AlN‐TiN/Al inoculant ribbons showed an excellent inoculant effect, which modified the dendrite crystals to equiaxed crystals and refined the grains from 122 ± 4 µm to 36 ± 5 µm by the addition of 0.3 wt% nano Al3Ti‐TiB2‐AlN‐TiN/Al inoculant ribbons. In addition to nano Al3Ti and TiB2 particles, nano AlN and TiN particles also have a certain orientation relationship with α‐Al, which suggests that these particles possess nucleation potency to α‐Al. After inoculation with 0.3% nano Al3Ti‐TiB2‐AlN‐TiN/Al inoculant ribbons, the ultimate tensile strength, yield strength, and average microhardness of the AlZnMgCu alloys increased from 246 MPa, 79 MPa, and 112 HV to 319 MPa, 100 MPa, and 136 HV, or by 29.7%, 26.6% and 21.4%, respectively.
Cognitive Biases in Street‐Level Resolutions: The Case of Multiple Claims in Tax Disputes
Authors: Gershgoren Sagi , Edri‐Peer Ofek , Cohen Nissim
Published: October 2024

Cognitive biases are an integral part of human conduct. However, we know little about how such biases affect street‐level bureaucrats' decision‐making. Without such an understanding, we might not have a complete picture about how street‐level bureaucrats make decisions. This incomplete picture can lead to the faulty implementation of public policy. This study focuses on cognitive biases that can impact decision‐makers faced with multiple claims. Using real‐world rulings made over 15 years by lower court judges in civil tax disputes, the findings reveal a positive association between the making of multiple claims by citizens in disputes with the state and the deciders' tendency to rule in their favor, especially when the ruling can be appealed. The findings also imply that the presentation of multiple claims can better the citizens' odds of receiving a favorable ruling. Policymakers who want to avoid such outcomes should take this factor into consideration.
In thermotolerance tests of tropical tree leaves, the chlorophyll fluorescence parameter Fv/Fm measured soon after heat exposure is not a reliable predictor of tissue necrosis
Authors: Winter K. , Krüger Nuñez C. R. , Slot M. , Virgo A.
Published: October 2024

Tropical rainforests are hot and may be particularly sensitive to ongoing anthropogenic global warming. This has led to increased interest in the thermotolerance of tropical trees.

Thermotolerance of leaves of two tropical tree species, Terminalia catappa and Coccoloba uvifera, was determined by exposing leaf samples to 15‐min heat treatments, followed by measurements of potential photosystem II quantum yield (dark‐adapted value of variable/maximum chlorophyll a fluorescence, Fv/Fm) after 24 h and 14 days, and visible damage (necrosis) after 14 days.

T50 (24 h), the temperature at which Fv/Fm declined by 50% 24 h after heat treatments, was associated with only ~10% leaf area damage in C. uvifera and no damage in T. catappa. In neither species was leaf necrosis observed at T5 (24 h), the temperature at which Fv/Fm declined by 5%. In both species, temperatures significantly higher than T50 (24 h) were required for 50% leaf area necrosis to occur. T50 (14 days) was a better proxy of visible leaf damage than T50 (24 h).

The relationship between heat‐induced Fv/Fm decline and tissue necrosis varies among species. In species surveys of leaf thermal tolerances, calibration of the Fv/Fm assay against the necrosis test is recommended for each species under investigation. Fv/Fm measurements soon after heat exposure do not reliably predict irreversible heat damage and may thus not be suitable to model and predict the thermostability of tropical forest trees.
Regulatory effect of pipecolic acid (Pip) on the antioxidant system activity of Mesembryanthemum crystallinum plants exposed to bacterial treatment
Authors: Gula Emilia , Dziurka Michał , Hordyńska Natalia , Libik‐Konieczny Marta
Published: October 2024

The presented study aims to elucidate the regulatory role of Pipecolic acid (Pip) in modulating the antioxidant system activity of Mesembryanthemum crystallinum plants exposed to Pseudomonas syringae infestation. M. crystallinum, known for its semi‐halophytic nature, can transition its metabolism from C3 to CAM under salt stress conditions. The research encompasses the antioxidant system of the plants, covering both enzymatic and low molecular weight components. The findings indicate that Pip supplementation confers a beneficial effect on certain elements of the antioxidant system when the plants are subjected to stress induced by bacteria. Notably, during critical periods, particularly in the initial days post‐bacterial treatment, M. crystallinum plants supplemented with Pip and exhibiting C3 metabolism display heightened total antioxidant capacity. This enhancement includes increased superoxide dismutase activity and elevated levels of glutathione and proline. However, in plants with salinity‐induced CAM, where these parameters are naturally higher, the supplementation of Pip does not yield significant effects. These results validate the hypothesis that the regulatory influence of Pip on defence mechanisms against biotic stress is contingent upon the metabolic state of the plant. Furthermore, this regulatory effect is more pronounced in C3 plants of M. crystallinum than those undergoing CAM metabolism induced by salinity stress.
Tree species and drought: Two mysterious long‐standing counterparts
Authors: Cisse El Hadji Malick , Pascual Lidia S. , Gajanayake K. Bandara , Yang Fan
Published: October 2024

Around 252 million years ago (Late Permian), Earth experienced one of its most significant drought periods, coinciding with a global climate crisis, resulting in a devastating loss of forest trees with no hope of recovery. In the current epoch (Anthropocene), the worsening of drought stress is expected to significantly affect forest communities. Despite extensive efforts, there is significantly less research at the molecular level on forest trees than on annual crop species. Would it not be wise to allocate equal efforts to woody species, regardless of their importance in providing essential furniture and sustaining most terrestrial ecosystems? For instance, the poplar genome is roughly quadruple the size of the Arabidopsis genome and has 1.6 times the number of genes. Thus, a massive effort in genomic studies focusing on forest trees has become inevitable to understand their adaptation to harsh conditions. Nevertheless, with the emerging role and development of high‐throughput DNA sequencing systems, there is a growing body of literature about the responses of trees under drought at the molecular and eco‐physiological levels. Therefore, synthesizing these findings through contextualizing drought history and concepts is essential to understanding how woody species adapt to water‐limited conditions. Comprehensive genomic research on trees is critical for preserving biodiversity and ecosystem function. Integrating molecular insights with eco‐physiological analysis will enhance forest management under climate change.
Before the ink dries? Creators misjudge idea thieves' preferences for early‐stage ideas
Authors: Ellis Lillien M. , Lucas Brian J.
Published: October 2024

In the knowledge‐based economy, creative ideas are becoming increasingly valuable. However, creators often encounter the threat of idea theft, which can discourage them from sharing their ideas and receiving vital feedback. This article explores the psychology behind creators' attempts to strategically manage idea sharing. Across three studies, we find that creators mispredict the preferences of idea thieves, such that idea thieves prefer to steal ideas in earlier stages of development than creators expect. We find this difference is driven by creators' tendency to underestimate how much idea thieves attend to moral concerns while deciding when to steal an idea. Further, we show that these mispredictions are consequential because they influence the stage at which creators choose to share their ideas for feedback.
Integrative description of Grevenius annulatus (Eutardigrada, Isohypsibioidea) from North‐West Russia with new data on the species cuticular structure leads to the institution of a new genus
Authors: Tumanov Denis V. , Shunatova Natalia N. , Fedyuk Ksenia A.
Published: October 2024

The phylogenetic position of the tardigrade species Grevenius annulatus was clarified using specimens from North‐West Russia. Molecular phylogenetic analysis revealed close affinity of this species with the family Isohypsibiidae. At the same time, its isolated position within this clade, supported by a set of unique morphological and biological characters, prompted the distinguishing of a new genus Cucumibius gen. nov. A new genus Chilibius gen. nov. was also established for Isohypsibius sculptus. We provide a detailed description of the ultrastructure of C. annulatus comb. nov. body cuticle. The newly discovered presence of a complex cuticle of the ‘heterotardigrade type’ in the superfamily Isohypsibioidea is discussed.
Biology, function and structure of the calcium homeostasis modulator family
Authors: Polfer Rachel , Furukawa Hiro
Published: October 2024

Calcium homeostasis modulators (CALHMs) are the most recently discovered members of the large‐pore channel family. They mediate the conductance of ions and larger molecules, such as ATP, and play critical roles in pathways related to Alzheimer's disease, neuroinflammation, neuromodulation, taste perception and innate immune responses. Since the inaugural report on CALHM1 in 2008, significant breakthroughs have revealed their biological roles, ion and ATP channel functions, and structures, positioning the field for further advancements. In this review, we discuss the overall progress and recent developments in understanding the biological roles, functions and molecular structures of CALHM proteins.

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Thermal Hydraulic Performance and Characteristics of a Microchannel Heat Exchanger: Experimental and Numerical Investigations
Authors: Pandey Vishwas Kumar , Choudhary Vishwjeet , Ranganayakulu Chennu , A. M. Aneesh
Published: October 2024

This paper presents extensive fluid flow and Heat Transfer studies conducted through an experimental setup followed by a detailed three-dimensional (3D) numerical analysis of the same setup using a commercial package for computational fluid dynamics (CFD), known as cfd-ace® for additive-manufactured counterflow AlSi10 Mg microchannel heat exchangers (MCHEs). A detailed 3D computational model of the experimentally tested MCHEs was built and analyzed using the commercial software cfd-ace® for the same experimentally tested operating conditions. The computational model results are in good agreement with experimental data of tested MCHE within +2% to +7% and ∼0% to −13.5% variation for cold and hot fluids for the entire set of design of experiments (DoEs). This percentage disagreement may be due to various factors, such as manufacturing deviation within tolerance, longitudinal conduction, variation in the thermal conductivity of the material after heat treatment, variation in environmental temperature, sensor deviation, and surface roughness of internal channels. Instead of Stainless steel (SST), AlSi10 Mg was used because of its lower manufacturing cost because AlSi10 Mg was lighter than SST, though its thermal conductivity is almost ∼8–10 times more than that of SST. A higher thermal conductivity is not good for MCHEs because it leads to higher longitudinal conduction, which eventually degrades the performance of MCHEs in terms of effectiveness. MCHE effectiveness is also reduced by ∼12% to 18% owing to longitudinal conduction from ideal effectiveness.
Investigating the Suitability of Cu2ZnSnS4 Thin Films for Gamma Radiation Dosimetry Applications in Nonmedical Environments
Authors: Obasi Chidiebere Ogonnaya , Ahmad Abubakar Soje , Okoroh Doris O. , Obi Echezona Simon
Published: October 2024

The need for the replacement of cadmium, indium, and tellurium in their compounds for sensor applications is a novel study. The copper zinc tin sulfide (Cu2ZnSnS4) thin films were synthesized from Cu (99.99%), Sn (99.99%), and Zn (99.99%) using the thermal evaporation method. The same volumetric parameters were maintained throughout the synthesis process. The films were further irradiated using an isotope of cesium-137 (Cs-137) from a gamma source at different doses (0–0.6 kGy) and dose rates of 0.1007 Gy/h at room temperature. Both the pristine (0 kGy) and irradiated (0.1, 0.3, and 0.6 kGy) films were characterized with a Raman spectroscope, a field emission scanning electron microscope (FESEM) with the JEOL JSM-7600F model, energy dispersive X-rays (EDX), an ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscope, and four-point probe techniques. The Raman results confirmed that all the films for both pristine and irradiated films have a main and secondary phases. The EDX results showed that the pristine and 0.1 kGy films were Cu-rich films, while the 0.3 kGy and 0.6 kGy films turned out to be Zn-rich films with an increase in gamma radiation dose. The optical properties of all the films showed also that the band gap decreased from 1.6 to 1.48±0.03 eV for the pristine and irradiated films, while the electrical resistivity results decreased as the gamma radiation dose increased. However, as the structural, optical, and electrical properties of the Cu2ZnSnS4 thin films responded linearly with the increasing gamma radiation dose, this suggests the usefulness and possibility of designing a new solid-state sensor for dosimetry applications to replace cadmium telluride (CdTe) and copper indium gallium sulfide (CIGS) thin films.
Experimental Study on Liquid Jet Trajectory in Cross Flow of Swirling Air at Elevated Pressure Condition
Authors: Kumar Deepak , Sikroria Tushar , Kushari Abhijit
Published: October 2024

Motivated by fuel atomization applications in gas turbine combustors, this paper presents an experimental examination of liquid jet trajectory and spray dynamics in crossflow of swirling air, at elevated pressure conditions. The study was conducted within an annular passage and was focused on momentum flux ratio and swirl number as the main parameters. The momentum flux ratio was varied from 2 to 25 through incremental adjustments to the liquid injection velocity and the swirl number values of 0.42 and 0.74 were used, representing typical gas turbine fuel atomization conditions. The jet trajectories were captured by imaging the three-dimensional (3D) helical path traced by the liquid jet using two mutually perpendicular optical windows. Radial penetration was quantified by solving the equations of a helix. The key findings revealed that radial penetration of the liquid jet is larger for higher momentum flux ratios and is influenced by the helical arc length. Notably, the radial penetration observed at low momentum flux ratios was larger for crossflow with lower swirl number and the radial penetration observed at high momentum flux ratios was more for crossflows with higher swirl number. In comparison to the spray characteristics in swirling crossflows at atmospheric pressure, condition of elevated gaseous pressure resulted in lower radial penetration, jet spread and jet area. The jet trajectory correlations for elevated pressure conditions are additionally presented, developed using curve fitting to the experimental data, which will be useful to the industry for estimation of spray trajectory in swirling crossflows at elevated pressure conditions.
Modeling Backlash-Like Hysteresis and Feedforward Control of Tendon−Sheath Mechanism Pair with Arbitrary Shape: Excluding Distal Sensory Input
Authors: Hong Junho , Hong Daehie , Kim Chanwoo , Won Seong Hyeon
Published: October 2024

The tendon−sheath mechanism (TSM) has garnered attention for its versatile applications in soft robotics, robotic hands, and surgical robots due to its adeptness in transmitting force through tortuous and narrow channels. However, the precise control of the TSM is challenging due to its shape-dependent deformation and force generation, highlighting the need to address shape variations in dynamic environments where direct measurement is impractical. This article introduces a novel methodology leveraging the concept of the equivalent circle in TSM to model its shape under varying conditions. The equivalent circle substitutes an arbitrarily shaped TSM with a circle, whose radius is derived from TSM's deformation and forces measured at the proximal end during calibration. This approach provides a concise and effective framework for understanding and analyzing the distinct characteristics of TSM. Additionally, a control strategy is proposed, utilizing the estimated equivalent circle to adapt to dynamic environments. Experimental results demonstrate promising performance without distal end sensory feedback, with mean percentage errors (MPE) of 0.78% and 2.33% for predicting cumulated curve angle and equivalent circle radius, respectively. Moreover, by utilizing the equivalent circle to calculate and feedforward deadband, effective control is achieved. The root mean square error (RMSE) reduced from 1.31 mm to an average of 0.19 mm in two feedforward experiments, representing an average reduction of 85.5%. These findings shed light on effective control strategies for TSM, offering valuable insights for robotics and surgical applications where TSM shape configurations are uncertain and subject to dynamic change.
Effect of Ceramic Matrix Composites on the Thermal Efficiency of a Power Generation Turbine
Authors: Tayade Ashrit , Lynch Stephen
Published: October 2024

Ceramic matrix composites (CMCs) offer higher allowable temperatures and reduced weight, making them an attractive prospect for parts in the hot section of a gas turbine engine. As CMCs are increasingly adapted into aero and land-based engines, there is a need to quantify the performance increase based on the potential for reduced cooling and increased firing temperatures. In this work, two static hot section components—the first-stage turbine vane and the first-stage turbine tip shroud (outer casing above the blade)—of a mid-sized power generation engine were modeled. Informed approximations about part geometry and cooling architectures were made to determine the cooling requirements of each part. Thermal boundary conditions for the turbine tip shroud and turbine vane were generated as a function of coolant mass flowrate using data from literature and applied to a 2D finite element analysis of the parts to determine maximum temperatures for both metallic and ceramic materials. A gas turbine cycle model was developed to simulate the performance of a mid-sized power generation turbine and used to determine the increase in efficiency due to a reduction in the cooling requirement for the CMC part compared to a conventional metal superalloy-based part. The potential reduction in chargeable cooling seen for the tip shroud ring was between 0.09% and 0.4% of the compressor mass flowrate, which corresponds to an increase in thermal efficiency between 0.11% and 0.45%. A similar analysis of the turbine vane resulted in a cooling reduction of 10.71% at the maximum turbine entry temperature considered which corresponds to a 3.4% increase in thermal efficiency.
Understanding the Flow Field in a Highly Loaded Tandem Compressor Cascade
Authors: Tran Thanh-Son , Babin Cedric , Fontaneto Fabrizio , Coussement Gregory , Verstraete Tom
Published: October 2024

Large flow turning in compressor cascades with single airfoils requires effective control of the boundary layer growth under the diffusing flow. An alternative approach consists of distributing the loading over two subsequent airfoils, using a so-called tandem blade, to, in some measure, restart the boundary layer before flow separation occurs. It is, however, not always clear whether the benefits of the two-blade setup justify the additional manufacturing complexity. The present work explores the tandem blade concept using a gradient-based optimization method to directly produce an efficient, highly loaded compressor cascade blade. A comparison between two-dimensional single and tandem configurations is first presented to clarify the benefits of one over the other. The geometry is optimized for each concept using a gradient-based optimization technique to improve the pressure loss coefficient at multiple operating points for a given flow turning constraint. While the optimized single and tandem blade designs have similar performance, the lower solidity of the latter provides a lighter compressor stage for the considered operating range. A three-dimensional tandem compressor cascade based on the two-dimensional study is optimized to account for secondary flows. The aerodynamic performance and the operating range are assessed and compared, along with an analysis of the physical phenomena surrounding the tandem configuration. The resulting geometry presents similar non-conventional features observed during the two-dimensional study that exploits the flow mechanism of two-airfoil configurations.
An Improved Eulerian–Lagrangian Method Combined With Ductile Material Model for Cavitation Erosion Assessment
Authors: Wang Ziyang , Cheng Huaiyu , Luo Xianwu , Peng Xiaoxing , Ji Bin
Published: October 2024

Cavitation erosion in hydraulic machinery constitutes a multifaceted, instantaneous physicochemical process resulting in material wear and decreased efficiency. This paper employs an enhanced Eulerian–Lagrangian method to evaluate cavitation erosion. The method captures erosive impact loads released by the nonspherical collapse of near-wall bubbles and integrates them with a one-dimensional ductile material mode, a capability lacking in traditional homogeneous mixture methods. A classic axisymmetric nozzle test case is conducted under four different cavitation numbers (σ = 0.8, 0.9, 1.09, and 1.6) to validate the reliability of the new approach. Qualitative and quantitative analysis demonstrates that the impact load distribution on the lower and upper walls aligns with experimental measurements. Compared with reference works, the new method accurately predicts the maximum wear position and yields a narrower erosion area closer to the experimental data. Moreover, the relative error of the minimum incubation time at σ = 0.9 on the lower wall calculated by the new method is 4.67%, and the relative error of the maximum wear rate is 36.6%. This method is pivotal for further studying how various materials respond to cavitation wear. Further analysis reveals that material response patterns are similar under cavitation erosion conditions at σ = 0.8, 0.9, and 1.09. In contrast, the material surface wear rate is reduced by 46.7%, and the incubation time nearly triples at σ = 1.6.
A Multilevel Model to Explain the Opportunities for and Experiences of LGBTQ+ People in Elite American Football
Authors: Cunningham George B. , Garrison Kelsey M. , Hussain Umer
Published: October 2024

American football holds immense cultural significance, from its impressive youth participation rates to the coverage of professional football. However, the reach of American football extends beyond cultural significance, as societal values and norms are frequently mimicked or even amplified in major sport settings. American football is a context that highlights the privileges of heterosexuality and cisgender people, effectively discouraging people from disclosing their lesbian, gay, bisexual, transgender, and queer (LGBTQ+) status. Because LGBTQ+ inclusion has received less attention in the American football context, and bias against LGBTQ+ people is common in sport, this paper aimed to explore LGBTQ+ inclusion in American football. Drawing on our related scholarship in this area, we present a multilevel framework, highlighting macrolevel (i.e., societal), mesolevel (i.e., organizational), and microlevel (i.e., individual) factors that shape LGBTQ+ inclusion in American football. The discussion includes strategies to implement LGBTQ+ inclusion in American football, as well as a call for further research.
Association Between Participation in Physical Education Classes and Physical Activity Among 284,820 Adolescents: A Progressive Exposure Gradient Analysis
Authors: Araujo Raphael H.O. , Werneck André O. , Jesus Gilmar M. , Filho Valter C.B. , Brazo-Sayavera Javier , Tremblay Mark S. , Silva Danilo R.P.
Published: October 2024

Purpose: The purpose of this study is to analyze the associations between participation in physical education (PE) classes and days with ≥60 minutes of moderate- to vigorous-intensity physical activity (MVPA) using different reference categories for participation in PE. Methods: We used self-reported data from 284,820 adolescents. Results: When no participation in PE was the reference, participation on 1 (prevalence ratio [PR] = 1.15 [1.12–1.18]), 2 (PR = 1.24 [1.20–1.27]), 3 to 4 (PR = 1.32 [1.28–1.36]), and  ≥5 days per week (PR = 1.8 [1.33–1.43]) increased frequency of days of ≥60 minutes of MVPA. Participating in PE on 2 (PR = 1.07 [1.02–1.09]), 3 to 4 (PR = 1.15 [1.12–1.18]), and ≥5 days per week (PR = 1.18 [1.15–1.22]) increased the days of ≥60 minutes of MVPA when participation in PE classes on 1 days per week was the reference. When participation in PE on 2 days per week was the reference, participation in PE classes on 3 to 4 (PR = 1.07 [1.04–1.09]) and ≥5 days per week (PR = 1.12 [1.09–1.15]) increased the days of ≥60 minutes of MVPA. Participating in PE classes on ≥5 days per week increased the days of ≥60 minutes of MVPA (PR = 1.05 [1.03–1.07]) when participation on 3 to 4 days per week was the reference. Conclusions: For those with no participation in PE classes, the addition of any PE classes could positively impact the weekly frequency of days of ≥60 minutes of MVPA. Even in countries/territories with large coverage of participation in PE classes, promoting more PE classes could be useful to increase physical activity.
Intervention Satisfaction and Feasibility of the Active Children Through In-Home, Web-Based Physical Activity (ACTIWEB-PA) Pilot Randomized Controlled Trial in Children
Authors: Rastogi Somya , Columna Luis , Koltyn Kelli , Gangnon Ronald , Peppard Paul , Malecki Kristen , Cadmus-Bertram Lisa
Published: October 2024

Purpose: We assessed feasibility and satisfaction of the Active Children Through In-Home Web-Based Physical Activity pilot trial, delivering a web-based movement integration intervention to children. Method: Eighty-two children (8–11 y), insufficiently active, were randomly assigned to either exercise intervention (n = 41) or wait-list control (n = 41). The intervention involved 20-minute exercise videos, 5 times weekly for 12 weeks, using the UNICEF Kid Power website at home. Feasibility metrics included recruitment (target: 70%), retention (target: 80%), adherence rates, and satisfaction assessed through surveys and interviews. Retention rate-1 was percentage completing posttest surveys, and retention rate-2 was percentage completing posttest accelerometry. Parent logs assessed adherence. Results: Recruitment, retention-1, and retention-2 rates were 73.6%, 93.9%, and 80.5%, respectively. The intervention group had 5 dropouts; wait-list control had none. Sixty-nine percent showed high intervention adherence. Parents consistently expressed satisfaction, finding the intervention enjoyable and beneficial. Although children initially provided positive reviews, their interest declined over time, with increasing expressions of monotony. Suggestions to increase novelty and incorporate a social component were made by participants. The intervention was also found to be particularly useful during inclement weather. Conclusion: Active Children Through In-Home Web-Based Physical Activity trial exceeded feasibility targets of recruitment and retention and achieved moderate overall adherence. Future trials should emphasize novelty and peer participation for improved adherence and satisfaction.
Learning to Pitch: A Review of Content in Sport Sales Courses
Authors: Barefoot Mandy , Martinez J. Michael
Published: October 2024

Sport-sales-specific coursework is emerging as a crucial addition to sport management curricula for a variety of institutions. However, a new sport sales course can present instructors with the unique challenge of developing a course without any departmental precedent. The current study collected syllabi from recent sport sales courses to provide a community-based solution to the deficit of historical sport sales course materials and syllabi in any given department. Syllabi were analyzed using a combined content-analysis approach. Findings include prevalent content themes, a summary of required materials, and the adaptability of skills learned through sales coursework. Similarly, the utility of microcredentials as course content in sport sales, a concept not previously explored in sport sales pedagogy literature, is highlighted by the current findings and discussed as an avenue for future research.
A Second-Generation Mindfulness-Based Intervention Focusing on Flow State: A Samatha-Based Training
Authors: Zhao Daliang
Published: October 2024

Currently, there is no empirical research on second-generation mindfulness training in the field of sport psychology. This study designed Samatha-based training (SBT) according to the principles of Samatha (a Buddhist practice) and preliminarily tested its influence on flow state. A total of 22 martial-arts-routine athletes were divided into two groups: the SBT group (n = 10) and the wait-list group (n = 12). The 7-week intervention demonstrated that SBT significantly enhanced the scores in present-moment attention, awareness, and flow state. These results support the effectiveness of SBT as a novel second-generation mindfulness-based intervention. Furthermore, the concept of mindfulness is discussed from the Samatha perspective, and subsequently, the reason that SBT promotes flow state was explored from a new perspective.