bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Adaptation of the Authentic Leadership Questionnaire in Turkish: Evidence From Nursing
Authors: Dirik Hasan Fehmi , Seren Intepeler Seyda , Hewison Alistair
Published: October 2024

There is a wide range of leadership approaches, and it is important to measure the types and impact of leadership in nursing. This study aimed to adapt the Authentic Leadership Questionnaire and test its suitability in the Turkish nursing context. Employing a two‐phase cross‐cultural research design in accordance with STROBE guidelines, language adaptation was conducted following ISPOR guidelines. Subsequently, data were collected from a sample of 382 nurses across three hospitals in İzmir, Turkey. The confirmatory factor analysis confirmed the four sub‐scale structures and indices revealed an adequate fit. The content validity index score was 0.97 for the questionnaire and greater than 0.80 for its items, demonstrating excellent validity. The intraclass correlation coefficient obtained was 0.80, indicating a good level of reliability. The findings confirm the questionnaire has the potential to determine the extent and impact of authentic leadership being practiced in hospital settings. It could be used in a range of hospital settings to ensure that accurate evidence concerning authentic leadership is gathered and used to inform the further development of nursing leadership more widely.
Nurses' Experiences With Virtual Consultations and Home‐Monitoring in Patients With Cardiac Disease: A Systematic Review and Qualitative Meta‐Synthesis of Results
Authors: Rosenstrøm Stine , Groth Sissel , Risom Signe Stelling , Hove Jens Dahlgaard , Brødsgaard Anne
Published: October 2024

To explore how nurses experience facilitators and barriers to the use of video‐consultations for home‐monitoring of patients with cardiac disease. A systematic literature search in PubMed, CINAHL, Scopus, and Web of Science was undertaken, inclusion criteria were qualitative data published between 2013 and 2023 written in English, Norwegian, Swedish, or Danish. Ten studies were included in the qualitative synthesis conducted as described by Braun and Clarke. From the synthesis, a main theme emerged: Nurses' uncertainty toward telemedicine is a risk toward the use of video‐consultations and home‐monitoring. The essence of the findings range from nurses' positive experiences to their frustration concerning the implementation process and the lack of technical support for clinicians and patients. Nurses often felt frustration and uncertainty about the quality of delivered care through virtual consultations. Working with technology in caring for patients with cardiac disease, including video‐consultations and home‐monitoring, nurses experienced a sense of insecurity. Insecurity was identified as a lack of technological knowledge, nurses' feelings of apathy, poorer observation through a video‐consultation, and the lack of organizational support.
Porphyromonas gingivalis Promotes Oral Squamous Cell Carcinoma Progression by Modulating Autophagy
Authors: Yuan Keyong , Xu Shengming , Liu Guanglong , Han Yong , Hu Jingzhou , Zhang Wuchang , Zhang Zhiyuan , Liu Liu , Huang Zhengwei , Zhu Yu , Liu Shuli
Published: October 2024

Objectives

Porphyromonas gingivalis (P. gingivalis) is a keystone periodontal pathogen associated with various gastro‐intestinal tract cancers. However, whether P. gingivalis can promote oral squamous cell carcinoma (OSCC) and the underlying mechanism associated with such promotion remain unclear.

Materials and Methods

In this study, OSCC xenograft models were used to evaluate the effects of P. gingivalis on tumor progression. The functional studies were done on several OSCC cell lines in vitro. P. gingivalis‐specific 16S rRNA fluorescent in situ hybridization (FISH) was used to test its prevalence in clinical samples.

Results

We found that P. gingivalis increased tumor volume and tumor growth in OSCC nude models. Functional studies demonstrated that P. gingivalis inhibited the apoptosis of OSCC cells by promoting cellular autophagy. P. gingivalis was more prevalent in FISH samples from patients with OSCC than from patients with leukoplakia or healthy subjects (70% vs. 47.2% vs. 33.3%, p = 0.045 and p < 0.001, respectively).

Conclusion

These data suggest that P. gingivalis plays an accelerating role in OSCC progression and contributes to OSCC by enhancing the autophagy pathway to reduce carcinoma apoptosis.
Diagnostic Accuracy of Toluidine Blue Electrospun in Detecting Oral Potentially Malignant Disorders
Authors: Supakornpichan Supanat , Tipduangta Pratchaya , Pongsiriwet Surawut , Chamusri Nutchapon , Ittichaicharoen Jitjiroj , Sriyaranya Nutchada
Published: October 2024

Objective

Oral potentially malignant disorders (OPMDs) with epithelial dysplasia can progress to oral squamous cell carcinoma (OSCC). Toluidine blue (TB) has been used in oral screening with various methods. This study aimed to evaluate the sensitivity and specificity of TB‐containing electrospun fibers in detecting OPMDs with epithelial dysplasia compared to histopathology.

Methods

The concentrations of polyvinylpyrrolidone (PVP) and TB were optimized for fiber diameter and puncture strength using the design of experiments method with a central composite design. These optimized fibers were tested on 36 suspected OPMD lesions in 30 patients, followed by a biopsy for histopathological examination.

Results

The quadratic and two‐factor interaction models described the relationship between TB and PVP concentrations and fiber characteristics. The TB‐containing electrospun fibers had 77.3% sensitivity and 35.7% specificity in detecting OPMDs with epithelial dysplasia.

Conclusion

The TB‐containing electrospun fibers offer advantages such as easy application, cost‐effectiveness, and enhanced sensitivity in identifying OPMDs with epithelial dysplasia. However, their diagnostic accuracy is insufficient as a standalone diagnostic method, and they should be considered an adjunctive tool for detecting dysplastic changes in the oral epithelium.

Trial Registration

Thailand Clinical Trials Registry: TCTR20240429002
Oral Health‐Related Quality of Life in Dutch Adults With Osteogenesis Imperfecta
Authors: de Kuijper‐Timmermans Emmanuelle , Blokland Lieke , de Kuijper Maurits , Kalaykova Stanimira , Zillikens M. Carola , Appelman‐Dijkstra Natasha M. , Gooijer Koert , Harsevoort Arjan , Janus Guus J. M.
Published: October 2024

Objective

To explore the oral health‐related quality of life and its possible risk factors among adults with Osteogenesis Imperfecta using the Oral Health Impact Profile (OHIP)‐49 questionnaire. Secondary objectives were to investigate the impact of self‐reported Osteogenesis Imperfecta, Dentinogenesis Imperfecta, and age on various dental parameters.

Materials and Methods

A cross‐sectional questionnaire was distributed online to 417 Dutch adults with Osteogenesis Imperfecta at three national referral centers. Multivariate linear regression was performed to identify indicators for OHIP‐49 Scores. The effect of Osteogenesis Imperfecta, Dentinogenesis Imperfecta, and age on various dental parameters was investigated using logistic regressions (p < 0.05).

Results

One hundred and fifty‐five questionnaires (37.2%) were suitable for analysis. Osteogenesis Imperfecta type III was significantly associated with higher OHIP‐49 scores as compared to type I. Symptoms of temporomandibular disorders, missing teeth or dentures also increased the OHIP‐49 scores significantly. Osteogenesis Imperfecta type IV and increasing age were associated with missing teeth. There was a 31.94 times (95% CI: 8.56–119.13) higher odds of tooth fracture with self‐reported Dentinogenesis Imperfecta.

Conclusions

Adults with Osteogenesis Imperfecta type III report a lower oral health‐related quality of life compared to Osteogenesis Imperfecta type I adults.
Ground beetle trophic interactions alter available nitrogen in forest soil
Authors: Lienau Janey R. , Duguid Marlyse C. , Schmitz Oswald J.
Published: October 2024

It is generally held that microbes exert primary control over nitrogen availability in temperate forests. Yet the role of soil and litter‐dwelling invertebrates to provide additional control via the breakdown of organic matter is an area of current exploration. Through trophic interactions within soil food webs, predators may indirectly affect prey with cascading effects on litter breakdown and nitrogen availability. The importance of these interactions, however, may be context‐dependent, varying with the stage of forest development and associated decomposer species composition given that young and old forests have vast differences in nitrogen availability, vegetation litter, soil properties and invertebrate functional groups. We examined ground beetle control over soil nitrogen and soil properties using a 68‐day mesocosm experiment that manipulated trophic structure (omnivore + predator beetles, predator beetles, and no beetles) in a young and old forest stand in the northeastern United States. In the young forest, net nitrogen mineralization decreased under predator + omnivore and the bulk soil C:N ratio in the old forest. However, we found no response in either forest context to the predator only treatment. Our study demonstrates the potential for ground beetles to strongly impact nitrogen availability and soil properties in forest ecosystems. Therefore, animal trophic interactions and their contexts must be included in our paradigm of nutrient cycles in temperate forests.
Size bias in the documentation of marine biodiversity
Authors: McClain Craig R. , Webb Thomas J. , Heim Noel A. , Knope Matthew L. , Monarrez Pedro M. , Payne Jonathan L.
Published: October 2024

Biodiversity exploration is incomplete, with a substantial gap between described and undiscovered species. Biases occur in these taxonomic descriptions, favoring easily observable and common species, leading to a skewed representation of ecological diversity, particularly in marine environments where deep‐sea life and smaller invertebrate groups remain underexplored. Here, we examine dynamics of taxonomic bias in describing marine biodiversity, emphasizing the relationship between the size of species and the timing of their formal description. Analyzing data from over 62 000 marine animal species across nine phyla, we find a significant inverse correlation: smaller species are consistently described more recently. This pattern persists across taxa and habitats, with fluctuations observed over time, including notable inflections coinciding with historical events and technological advancements. These results underscore the implications of taxonomic bias for ecological understanding and conservation efforts, emphasizing the importance of completing inventories of marine life, particularly focusing on small‐bodied, potentially threatened species.
Postoperative Harris Hip Score Versus Harris Hip Score Difference in Hip Replacement: What to Report?
Authors: Ramadanov Nikolai , Voss Maximilian , Hable Robert , Hakam Hassan Tarek , Prill Robert , Salzmann Mikhail , Dimitrov Dobromir , Becker Roland
Published: October 2024

Background

Reliable scientific information is crucial for assessing hip function and evaluating the success of hip surgery. The Harris Hip Score (HHS) is the most widely used tool for measuring hip function and, in particular, the outcomes of hip surgery. The aim of this study was to conduct a systematic review of the literature to identify randomized controlled trials (RCTs) that reported the HHS for hip replacement treatment groups and to test whether there was a substantial difference between reporting only the postoperative HHS or the HHS difference (HHSdiff).

Methods

PubMed, CNKI, and Epistemonikos were searched until March 1, 2024. The risk of bias, level of evidence, and publication bias were assessed. As HHS is a continuous outcome, mean difference (MD) with 95% confidence intervals (CIs) was calculated using the Hartung–Knapp–Sidik–Jonkman method and a common‐effect/random‐effects model. The same approach was used for both postoperative HHS and HHSdiff. The effect of the two treatment groups studied (minimally invasive vs. conventional approach) on postoperative HHS was then compared with the effect of the two groups studied on the difference in HHS.

Results

A total of 41 RCTs, involving 3572 patients, with a low to high risk of bias and a low to moderate publication bias were included. The measured outcome parameters showed a low to moderate level of evidence. There was no relevant difference in the reporting of HHS only postoperatively or HHSdiff when comparing two hip replacement treatment groups in RCTs, measured at 0–0.5, 3, 6, and 12 months postoperatively.

Conclusion

The present study showed that there is no relevant difference between reporting of the HHS only postoperatively or HHSdiff when comparing two hip replacement treatment groups in RCTs. Both methods of HHS reporting produced comparable results in an identical cohort of 3765 patients undergoing hip replacement surgery.
Optimizing the anesthetic care of patients with aromatic l‐amino acid decarboxylase deficiency
Authors: Kanjia Megha K. , Jooste Edmund H. , Illig Melissa , Neifeld Capps Jennifer , Eisner Christoph , Fan Shou Zen , Lenarczyk Jerzy , Wojdacz Rafał
Published: October 2024

Aromatic l‐amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive disorder that results in a lack of the monoamine neurotransmitters dopamine, serotonin, norepinephrine, and epinephrine. Patients present with a wide spectrum of symptoms, including motor and autonomic dysfunction, hypotonia, and developmental delay, often before the age of one. Until recently, treatment options were limited to symptom control, but the recent approval of the first gene therapy for AADC deficiency in Europe and the UK has provided an alternative to treating symptoms for this disease. Eladocagene exuparvovec is a one‐time gene therapy, administered bilaterally to the putamen by magnetic resonance imaging‐guided stereotactic neurosurgery. While administration of the gene therapy itself is minimally invasive, the anesthetic management of patients with AADC deficiency is challenging due to the absence of sympathetic regulation secondary to the lack of adrenergic neurotransmitters. Optimal anesthetic management requires an understanding of the complex and heterogeneous nature of the disease. Hemodynamic instability, temperature dysregulation, and hypoglycemia are of primary concern, but there are also challenges regarding intravenous access and airway management. A thorough preoperative assessment is essential and should be guided by the patient's history. Advanced planning is necessary regarding the timing of the procedure schedule and operative plan; meticulous preparation, simulation for the operating room, as well as communication with all perioperative staff members, are crucial. Intraoperatively, utmost care must be taken to protect the skin, maintain body temperature, and to prepare for inotropic and/or glycemic support as needed. Postoperative intensive care management is necessary for consideration of postoperative extubation and provision of supportive care. With careful planning, preparation, and vigilance, patients with AADC deficiency can safely undergo anesthesia.
Longitudinal effects of father‐adolescent attachment on anxiety: A multi‐informant study
Authors: Vetterly Savannah , Dennis Sarah Hoegler , Davies Patrick T. , Cummings E. Mark
Published: October 2024

Research has demonstrated that many elements of the family context can play a significant role in the development of anxiety in adolescents. Some work suggests that parent‐adolescent attachment may serve as an antecedent of adolescent anxiety problems, but there remains a gap in research that examines both the mother‐adolescent and father‐adolescent attachment relationship and its impact on adolescent anxiety. Evidence suggests that parent‐child attachment security may provide a context for the development of emotion regulation skills; if an adolescent lacks these important regulatory capabilities in a time of stressful transitions, this may be related to increased feelings of anxiety. However, little is known about the particular effects of father‐adolescent attachment on anxiety, especially in early to mid‐adolescence. The present study addresses parental influences on the development of adolescent anxiety in a sample of 295 mothers, fathers, and adolescents studied across three years. Two dyadic growth‐curve models were specified: one for mother‐adolescent dyads and the other for father‐adolescent dyads. Results indicated that linear increases in adolescent reports of secure attachment with their fathers were predictive of linear decreases in adolescent reports of anxiety. Interestingly, there were no significant effects for the mother‐adolescent model. The results call attention to the developmental significance of attachment to fathers in buffering adolescents from emerging anxiety in this developmental period. The present study contributes to a growing body of research that highlights the importance of the father‐child relationship in adolescence.
Cow dung compost and vermicompost amendments promote soil carbon stock by enhancing labile organic carbon and residual oxidizable carbon fractions in maize field soil
Authors: Pan Chia‐Chen , Huang Cheng‐Hua
Published: October 2024

Enhancing soil quality and promoting the accumulation of soil organic carbon through economically and environmentally sustainable practices are essential for modern agriculture. This study aimed to investigate the effects of various organic amendments and rotation systems on soil properties and sweet corn growth in sandy loam soil. A split‐plot field experiment was conducted over 2 years, including rotations with or without Sesbania sesban as the main plot and six fertilizer treatments: a no fertilizer control, chemical fertilizer and four organic amendments as subplots. The cropping system did not significantly influence soil properties and sweet corn growth. However, the application of soybean meal, castor meal, cow dung compost and vermicompost resulted in sweet corn yields comparable to those achieved with the chemical fertilizer treatment. Notably, the soil organic matter (SOM) content was significantly higher in the cow dung compost and vermicompost treatments compared with both the no fertilizer and chemical fertilizer treatments. Moreover, these two amendments significantly increased soil carbon stock because of significant increases in labile organic carbon (TOC400) and residual oxidizable carbon (ROC) fractions in the maize field soil. A significant positive correlation was observed between fresh ear weight with husks and several soil parameters, including electrical conductivity, available P, exchangeable K and Zn, NO3–N, NH4–N, inorganic C and N, TOC400, ROC and SOM. In conclusion, cow dung compost and vermicompost not only result in sweet corn yields comparable to those from chemical fertilizer but also significantly enhance soil carbon stock by increasing TOC400 and ROC. Therefore, they can partially substitute for chemical fertilizers in promoting sustainable agricultural production of sweet corn.
Identification of the Novel HLA‐DQB1*06:432 Allele by Sequence‐Based Typing
Authors: Yang John Jeongseok , Oh Heung‐Bum
Published: October 2024

HLA‐DQB1*06:432 differs from HLA‐DQB1*06:09:01:01 by a nonsynonymous nucleotide substitution in codon 186, changing Valine to Methionine.
Workplace affordances and learning engagement in a Thai paediatric intensive care unit
Authors: Trisukhon Kanaporn , Thammasitboon Satid , Vaewpanich Jarin , Petrescu Matei , Punyoo Jiraporn , Jongaramraung Jongjai , Pakakasama Samart , Balmer Dorene F.
Published: October 2024

Background

Workplace learning in critical care settings is complex and challenging. Research has explored learner‐, teacher‐, and context‐related factors that influence medical residents' engagement in critical care workplaces in Western but not in non‐Western cultures. This limits our understanding of workplace learning globally and how we can better support resident learning in diverse cultures.

Objective

To explore how paediatric residents engage in workplace learning in a Thai Paediatric Intensive Care Unit (PICU) and how this culturally situated workplace shapes their learning.

Methods

In this qualitative study, we recruited paediatric residents (n = 16) from a tertiary care hospital in Thailand for semi‐structured interviews. We used reflexive thematic analysis to describe, analyse and interpret residents' experiences of workplace learning, and to capitalise on our own experience as an analytic resource.

Results

We constructed three themes to represent participants' narratives: PICU cases and context as dynamic affordances; impact of psychological safety; and the role of attending physicians. While Thai PICU cases and context could afford participation and thus learning, Thailand's collectivist culture, which prioritises group needs over individual needs, contributed to a sense of psychological safety within culturally‐endorsed, professional and social hierarchies, and set the stage for workplace learning. Despite their higher status in these hierarchies, attending physicians facilitated resident learning by fostering open dialogue, joint problem‐solving and a low‐stress atmosphere.

Conclusions

Workplace learning in a Thai PICU while challenging, is uniquely facilitated by Thailand's collectivist culture that fosters psychological safety and attending physicians' invitation in, and learn from, the workplace optimises learning.
DGAG: A Novel Approach That Detects Green Areas With Geolocation From Large‐Scale Satellite Imaging Instance Segmentation and GIS Application
Authors: Taşyürek Murat , Kılıçkaya Fatma Nur , Öztürk Celal
Published: October 2024

Advancements in space exploration and computing have accelerated progress in remote sensing studies, where imaging satellites capture extensive datasets globally, particularly in identifying green areas on agricultural lands essential for monitoring natural resources, promoting sustainable agriculture, and mitigating climate change. Large‐volume satellite images from 2020 were obtained from https://tile.kayseri.bel.tr/tilecache/Cache/2020UYDU3857/z/x/y.jpeg. The images are stored on the server address of Kayseri Metropolitan Municipality. Traditional techniques struggle with classifying big data from these satellite views, necessitating innovative approaches like DGAG (Detect Green Areas with Geolocation), a novel method that combines interdisciplinary techniques to detect and geographically delineate green areas on agricultural lands globally. DGAG utilizes map‐based open‐source software to convert large‐scale satellite views into processable images with spatial information, employing segmentation‐based deep learning techniques such as You Only Look Once version 5 (YOLOv5) and Mask Region‐based Convolutional Neural Network (Mask R‐CNN) to extract green areas and determine pixel boundaries. The pixel borders are then transformed into spatial polygon data, providing hectare‐level spatial information. Testing on actual satellite views of Kayseri province yielded promising results, with DGAG YOLOv5 and Mask R‐CNN achieving F1 scores of 0.917 and 0.922, respectively. Notably, DGAG Mask R‐CNN outperformed YOLOv5 by detecting 834626.42 square meters more green area. In terms of runtime, DGAG Mask R‐CNN detected green areas in approximately 0.031 s, while DGAG YOLOv5 operated roughly twice as fast, detecting green areas in about 0.015 s.
New strategies to classify canine pleural effusions and the diagnostic value of acute phase proteins, amylase, and adenosine deaminase in pleural exudates
Authors: Zoia A. , Morini L. , Mazzei A. , Talavera Lopez J. , Pardo‐Marín L. , Cerón J. J. , Tecles F.
Published: October 2024

Background

In dogs, simplified Light's criteria can discriminate transudates from exudates. Other tests used in human medicine are pleural effusion cholesterol (CHOLPE) and butyrylcholinesterase [BChEPE], the pleural effusion/serum ratio of these analytes (CHOLratio and BChEratio), and the serum albumin minus pleural effusion albumin gradient (SEAG).

Objectives

We aimed to assess the diagnostic accuracies of different biomarkers in dogs with pleural effusion in differentiating exudates from transudates. Secondarily, we evaluated the potential diagnostic utility of pleural effusion acute phase proteins, amylase, and adenosine deaminase in discriminating causes of exudative effusions.

Methods

Cross‐sectional study including 68 client‐owned dogs with pleural effusion.

Results

There were 48 exudates (10 septic, 16 neoplastic, 9 hemorrhagic, and 13 classified as other exudates) and 20 transudates. All the variables analyzed, except SEAG, were significantly different between exudates and transudates. Using the cut‐off values adopted in human literature, accuracies for CHOLPE, CHOLratio, BChEPE, and BChEratio were between 82.35% and 85.29%; all values were significantly lower compared with the previously published simplified Light's criteria accuracy (i.e., 98%, p < .001 for all comparisons). We found the accuracy of the simplified Light's criteria to be similar to what has been previously reported (95.59%, p = .238). Paraoxonase–1 (PON–1PE) activity and the pleural effusion/serum paraoxonase‐1 ratio (PON–1ratio) were significantly lower in exudative neoplastic effusions than in exudative hemorrhagic (p = .004 and p = .001) and septic (p = .004 and p < .001) effusions.

Conclusion

Simplified Light's criteria were the best method for discriminating transudates from exudates, and a low PON–1PE activity and PON–1ratio in exudative effusions may suggest an underlying neoplasia.
An Aerodynamic Investigation of a High-Pressure Turbine Using Rotor Casing Static Pressure Measurements at Engine Representative Conditions With Different Tip Designs, Tip Gaps, and Inlet Temperature Profiles
Authors: Singh Deepanshu , Beard Paul F. , Cardwell David , Staelens Vianney , Bahulekar Pratik , Stokes Mark , Bather Simon , Chana Kam S.
Published: October 2024

A rotating high-pressure (HP) turbine, in modern aircraft engines, is subjected to high cyclic thermal and mechanical loads. Shroudless turbines experience high heat loads on the rotor tip and casing, which makes them one of the life-limiting components of an engine. If the rotor tip starts to erode, then the tip clearance increases, which increases the over-tip leakage flow, resulting in reduced stage efficiency and ultimately, the engine lifetime. Since the 1970s, extensive research has been undertaken to understand the over-tip leakage flow and develop mitigation strategies such as novel tip designs, to minimize the losses and heat load. However, the majority of the present findings are based on linear cascade or low-speed rotational studies, due to the high cost of the experiments and difficulty in instrumentation at engine conditions. Recent studies (mostly numerical) have shown the importance of testing at engine-representative conditions, specifically targeting the transonic tip flow in a high-speed rotational environment, which is essential for an accurate understanding. The Oxford Turbine Research Facility (OTRF) is a high-speed rotating transient test facility that allows unsteady aerodynamics and heat transfer measurements, at engine representative conditions. This article presents an experimental investigation of the HP turbine rotor casing aerodynamics, performed in the OTRF. Steady and unsteady casing static pressure measurements were acquired, using pneumatic lines and high-frequency response (∼100 kHz) Kulite pressure transducers, respectively. The single-stage HP turbine consisted of cooled vanes (featuring film and trailing-edge slot cooling) and uncooled rotor blades. Three different tip designs (two squealers and one flat) were tested, at two tip gaps, and with two inlet temperature profiles that included a spatially uniform total temperature profile and an engine-representative HP turbine inlet total temperature profile. In parallel, a numerical investigation of the experimental test cases is presented using unsteady computational fluid dynamics (CFD) predictions. The experimental results from this study provide a unique dataset to validate numerical models.
Analysis of Force Distribution and Motion Characteristic of Hybrid-Driven Tensegrity Parallel Mechanism
Authors: Zhu Wei , Zhou Xiaoyu , Zhu Yongjing , Ma Zhilong
Published: October 2024

Tensegrity parallel mechanisms is a novel spatial structure composed of cable-based and rigid-based chains, which is characterized by lightweight, multi-stability, high precision, good stiffness, and high load-bearing capacity. This paper focuses on the six-degree-of-freedom tensegrity parallel mechanism, analyzing its static equilibrium and presenting the force equilibrium equations. A model for cable tension distribution optimization is established, utilizing different P-norm objective functions to optimize the distribution of tension in cables and rigid links, discussing the reasons for unreasonable tensions in the system. Under given constraints on the motion pairs of the mechanism, the workspace of the mechanism is plotted, and factors influencing the size of the workspace are analyzed. Finally, the singularity of the mechanism is addressed based on the Jacobian matrix, demonstrating the feasibility of reaching the space volume by the mechanism. It has certain reference significance for the configuration theory and analysis methods of tensegrity parallel mechanisms and rigid-flexible coupling mechanisms, and provides a reference for the further promotion and application of mechanisms.
Designing Multi-axis Compliant Mechanisms With Lockable Decoupled Inputs: A Tip–Tilt Case Study
Authors: Vazzoler Greta , Shimohara Sam , Berselli Giovanni , Hopkins Jonathan B.
Published: October 2024

This research is about designing multi-degree-of-freedom (multi-DOF) compliant mechanisms with decoupled inputs that can be independently locked/unlocked using bistable switches to achieve different combinations of DOFs. A case study mechanism achieving two decoupled rotational DOFs (tip and tilt) is designed, fabricated, and characterized. It can be triggered using two pairs of bistable switches, achieving drastically different states of torsional stiffness for each DOF in four sets of DOF combinations—no DOFs, a tip DOF, a tilt DOF, and both tip and tilt DOFs. Bistability and stiffness cancelation principles are exploited to achieve the desired changes in stiffness. Two flexure elements can be identified—the switch providing a negative stiffness and the cross-axis-flexural-pivot (CAFP) producing a positive stiffness. The mechanism is tuned to achieve static balancing, reaching a near-zero stiffness over much of its range. The pseudo-rigid body model and two-dimensional (2D) finite element model (FEM) are combined defining a fast method to dimension the system. The 3D FEM is simulated to validate the obtained results. For each DOF, the system is tested in two configurations (stiff and compliant) for three cycles over a ±10 deg rotation, achieving a stiffness reduction of around 99%. Comparable stiffness values were measured after triggering the switches more than once, repetitively reaching the required two states of stiffness, confirming the system's usability in practical applications. The positive stiffness provided by the CAFP is measured and compared to the device's overall stiffness, highlighting the stiffness cancelation concept.
Environmental Assessment of Centralized and Decentralized Scenarios of Green Hydrogen Implementation in the Transportation Sector
Authors: Cortez Luis D. , Tapia-Bastidas C. V. , Helguero Carlos G. , Maldonado Fausto A. , Alava Eduardo , Hidalgo-Crespo José , Amaya-Rivas Jorge L.
Published: October 2024

As the transportation sector progresses towards achieving net-zero emissions, Battery Electric Vehicles (BEVs) have taken the lead in the decarbonization process. Nonetheless, these vehicles face challenges to fully replacing conventional transport modes, such as limited range and extended charging times. Moreover, there are Greenhouse Gas (GHG) emissions linked to electricity used to charge them, due to the non-renewable sources present in the local grid of every country. Green Hydrogen, recognized as a clean energy carrier, emerges as a pivotal solution to decrease these emissions, facilitating electricity or heat generation while producing zero GHG emissions. In this study, the viability of using green Hydrogen, particularly in conjunction with Fuel Cell Plug-in Hybrid Electric Vehicles (FC-PHEVs) offering enhanced range and faster refueling compared to conventional BEVs, is evaluated to achieve net-zero emissions. Cradle-to-grave life cycle models for Hydrogen implementation in Centralized and Decentralized scenarios are developed to assess its environmental impacts for further comparison with a BEV scenario. The results indicate that the Decentralized scenario is less polluting due to a notable portion of GHG emissions associated with Hydrogen transportation. However Centralized scenario requires less electrical consumption. Finally, BEVs produce higher emissions because of their low range and the electricity origin.
Investigation of Liquid Film Behavior on the Surface of an Airfoil in a High-Speed Flow and Subsequent Atomization From the Trailing Edge - Effect of Airfoil Shape
Authors: Safiullah  , Esquivias Brandon , Hickey Brendan , McDonell Vincent , Tabata Soichiro , Senoo Shigeki
Published: October 2024

The breakup of liquid films in high-speed flows is found in many applications. These include pre-filming air-blast atomization found in fuel injectors and shedding from airfoils. In this work, the effect of airfoil shape on the liquid film flow on the surface and subsequent atomization from the trailing edge of the airfoil is investigated. Specifically, a symmetric airfoil (NACA0012) and an asymmetric airfoil (NACA2312) are studied and are placed in a high-speed flow of air at velocities up to 175 m/s. Water was introduced onto one side of each airfoil via 26 0.5 mm diameter holes spaced 1 mm apart. These holes are positioned 35 mm downstream from the leading edge and 65 mm upstream from the trailing edge. Water flow rates between 1.4cm2/s and 2.6cm2/s are used. Liquid film behavior is characterized by 1) point measurements of dynamic liquid film thickness using a confocal arrangement of laser induced fluorescence and 2) high-speed video to visualize liquid accumulation and measure ligament breakup length at the trailing edge. Laser diffraction is used to measure line of sight average droplet sizes. Finally, Phase Doppler interferometry is used to measure spatially and temporally resolved droplet size and velocity in the pitchwise direction at 70mm downstream trailing edge distance. The film thickness formed on the suction surface of NACA2312 is thicker than on the pressure surface and on NACA0012 which is attributed to larger adverse pressure gradientand thicker air boundary layer. Ligament lengths are almost identical for films on either surface of the NACA2312 vane. This confirms that the trailing edge vortices have minute influence on the atomization at an immediate distance from the trailing edge. Phase Doppler results indicate that the spray produced from the suction side of NACA2312 and NACA0012 airfoils are symmetric about the center of the vane while introducing water from the pressure surface of NACA2312 shifts the spray 3 mm on the same side. This is confirmed from the droplet size distribution specifically at higher velocities. This is consistent with the stronger trailing edge vortices on the pressure surface at high air velocity (175m/s) and at a distance well below the trailing edge (approximately 0.7c) The results demonstrate that the shape of the airfoil can have an impact on spray distribution from the trailing edge.
Modeling and Control of a High Voltage Battery Pack Cell for Electric Vehicles
Authors: Villalobos Jesus , Garrick Taylor R. , Moghadam Rohollah
Published: October 2024

Consumer vehicles have been propelled by internal combustion (IC) engines for more than a century. They are extremely convenient but have consequences such as global warming and air pollution. As a result of the demand to shift away from fossil fuels, battery electric vehicles (BEV) have grown in popularity, both domestically and across the globe. To reduce the time to market, and to reduce time spent testing prior to final design, modeling and simulation can be used to analyze and drive design of battery cells as utilized for vehicle propulsion. Therefore, a simulation model is proposed using an equivalent circuit model using MATLAB and Simulink, resulting in the potential for hardware tests elimination which results in cost reduction. To generate such models, a set of parameters can be extracted from cell test data across various operating conditions to create a linear mathematical model that predicts the voltage of a cell across varying loads. This cell model can then be scaled in relation to the pack configuration to model a full vehicle high voltage battery pack. The mathematical model can be used to design a state observer even if the cell’s initial conditions are not available.
Identification of Control State Changes in a Power Plant Desuperheater System via Transfer Functions and Gaussian Process Modeling
Authors: Nascimento Claudemi , Alves Victor , Harun Nor Farida , Zhou Nana , Bryden Kenneth M. , Shadle Lawrence J. , Tucker David , Lima Fernando V.
Published: October 2024

This work presents a novel study for identifying alterations in the control states of a desuperheater system based on real closed-loop data from a coal-fired power plant operating under various loads using linear and nonlinear system identification techniques. Specifically, Transfer Functions (TFs) and Gaussian Processes within a Nonlinear AutoRegressive eXogenous model (GP-NARX) are utilized. The desuperheater system comprises two units, north and south, each modeled as a single-input single-output (SISO) system based on spray valve positions and outlet temperatures. To identify changes in the control states using TFs, deviations in the coefficients of three poles and two zeros transfer functions are analyzed. Significant shifts in the control states of the north desuperheater are observed when transitioning from nominal to half and low loads, with deviations of up to four orders of magnitude. Substantial changes in control states are also observed for the south desuperheater when moving from nominal to low load, with a deviation in the coefficients of up to five orders of magnitude, whereas the transition from nominal to half load shows a smaller deviation of up to three orders of magnitude. In the GP-NARX approach, model uncertainties are used to indicate the changes in the control states. The south desuperheater showed a significant uncertainty of up to 8°F from the nominal to the low load, evidencing a change in the control states. Regarding the north desuperheater, increased uncertainty, up to 6°F, is also observed but in shorter time intervals when compared to the south desuperheater. Ultimately, this work shows that both approaches can be used as a basis for system identification, employing real closed-loop power plant data.
Root Cause Analysis of the Catastrophic Failure of a Propylene Recycle Compressor
Authors: Abidogun Kamorudeen
Published: October 2024

A 2-section, 6-stage propylene recycle compressor experienced a catastrophic failure that resulted in extensive damage to its internals. The compressor was restarted after tripping on a low-low seal oil differential pressure without draining the compressor casing, resulting in a subsequent tripping of the compressor with audible noise. The initial convergence of opinions, before the current investigation, was that the compressor failed due to surge. This appears a plausible conclusion since the anti-surge system had been disabled long before the disastrous failure. Also, the nature of the failure — broken rotor blades and diaphragms, bent rotor, among others — are hallmarks of compressor failure due to surge. However, a detailed review of the process data from the database and thermodynamic performance calculations using in-house developed software by this investigator revealed that both compressor sections have been operating across all sections of the characteristic curves, from extreme left to extreme right of the curves, before and after the catastrophic failure. Radial and axial vibrations are below alarm limits when the compressor was operating at these two extremities of the characteristic curve. Significant, rapid pressure/flow and high vibration fluctuations, which characterizes flow instabilities, were not recorded before the compressor tripped, suggesting that the compressor did not experience surge before the failure. Seal oil ingresses into the compressor in large quantities due to failed mechanical seal is suspected as the root cause of the catastrophic failure because the compressor was restarted after checking all permissives without draining the compressor casing.
Enhancing performance of microbolometers by utilizing low-temperature polycrystalline silicon
Authors: Jung Taeseung , Kim Seungyeob , Lee Sangho , Ahn Jinho , Jeon Sanghun
Published: October 2024

In response to the urgent need for advanced noncontact temperature sensing technologies to mitigate pandemic transmission, there has been a notable surge in global demand. Thermal cameras, combined with infrared sensors, are critical not only for high-resolution imaging but also for cost-effective commercialization. Amorphous silicon-based microbolometers offer advantages in terms of integration and cost compatibility with conventional silicon processes. However, they suffer from limitations in their electrical properties, particularly in the noise-equivalent temperature difference. This study examines the effectiveness of low-temperature polycrystalline silicon (poly-Si) as an active material for microbolometer cells compared to amorphous silicon, focusing on improving the temperature coefficient of resistance (TCR) and lowering the noise density. Our investigation reveals that various parameters, such as dehydrogenation temperatures ranging from 350 to 550 °C, diverse laser annealing techniques (including single, step and multishot methods), and laser power density levels ranging from 150 to 300 mJ/cm2, influence the grain size trends of poly-Si. Using these methods, we produced poly-Si films with grain sizes ranging from 15 to 40 nm, which were used as the active layer in bolometer cells. The final part of our study assessed the TCR and noise density in devices with different poly-Si grain sizes. The TCR/noise density ratio was 3.5 times better in poly-Si devices compared to amorphous silicon devices. This study evaluates poly-Si as an active material for microbolometers, paving the way for future research and development in next-generation infrared sensor technology.
Computation of acoustic scattered fields and derived radiation force and torque for axisymmetric objects at arbitrary orientations
Authors: Tang Tianquan , Zhang Yumin , Dong Bin , Huang Lixi
Published: October 2024

This study presents a theoretical framework for calculating acoustic scattering fields, as well as radiation force and torque resulting from the interaction between an incident wave and an axisymmetric object positioned at arbitrary orientations. Grounded in the partial-wave expansion method, it formulates scattering products using beam-shape and scalar scattering coefficients. The incorporation of geometric features into the scalar scattering coefficients is achieved through the conformal transformation approach. Notably, its applicability is restricted to scenarios where the object is positioned at its standard orientation, a limitation circumvented by employing rotational transformations to extend the model to non-standard orientations. A rotational transformation tunes the original frame (observation coordinate system) into a reference frame (computation coordinate system), for any deviated orientation and facilitating solution of scattering products. While the non-intuitive nature of rotational transformations disrupts the inheritability of the partial-wave expressions for the scattering products, an alternative approach is provided based on rotation addition theorem. This method directly incorporates object orientations into the beam-shape and scalar scattering coefficients, bypassing rotational transformations and preserving the partial-wave format. Comparative analysis with full three-dimensional numerical simulations shows theoretical methods are computationally more efficient while ensuring substantial consistency.
Association between perceived sound type dominance and overall assessment of the acoustic environment using ISO 12913 soundwalks
Authors: Hornberg Jonas , Hemker Falk , Schröer Kai , Hinse Mara , Moebus Susanne , Schröder Judith
Published: October 2024

Transformations of cities into sustainable, health-promoting environments require high-quality acoustic settings. The soundwalk approach according to ISO 12913 (International Organization for Standardization, Geneva, Switzerland) is a participatory tool to assess acoustic environments. Investigation of the relationship between perceived sound type dominance and overall assessments of the surrounding sound environment, comparing two urban areas. Using data of n = 35 soundwalks according to ISO 12913 conducted in an urban neighbourhood and an inner city area in Essen, Germany (2022–2023), 91 participants evaluated, among others, sound type dominance and overall assessment along two routes with six listening stations each. Statistical analyses included descriptive and linear mixed model analyses adjusting for gender, age, wind speed, and temperature. Perceived traffic noise negatively impacts the overall assessments (ß = −0.44, 95% CI: −0.50; −0.38), which is more pronounced in the residential neighbourhood than in the inner city area (−0.59 [−0.69; −0.51], respectively, −0.30 [−0.41; −0.20]). Natural sounds have a positive effect (0.13 [0.08; 0.19]) whereas human sounds showed no effect (−0.07 [−0.12; −0.01]) on the overall assessment. The adjusted effect estimates remain virtually unchanged. The results highlight traffic noise's profoundly negative impact on overall acoustic assessments. The high number of repeated soundwalks provide a robust data set for future evaluations.
Technology Use Among Physical Education Teachers Before, During, and After the COVID-19 Pandemic: A Connectivist Approach
Authors: Ha Taemin , Fan Xiaoping , Cardina Catherine , Treadwell Sheri M.
Published: October 2024

Purpose: Through the use of a connectivist approach, this study explored how physical education teachers engaged with technology before, during, and after the COVID-19 pandemic. Method: A convergent parallel mixed-method research design was used to collect both quantitative and qualitative data through an online survey, which were then analyzed. Descriptive statistics were used to analyze the quantitative data, while open and axial coding techniques were used for qualitative data analysis. Results: Despite facing difficulties in adopting technology during the pandemic, unexpected opportunities were presented such as using technology for professional development purposes. Furthermore, the use of technology among teachers increased postpandemic compared with prepandemic levels. Discussion/Conclusions: By viewing the findings through a connectivist approach as a theoretical lens, technology offers diverse resources teachers can use to enhance their teaching practices, as well as serve as a tool for online learning.