bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene–environment interplay linking perceived parental supervision and peer drunkenness with Chinese adolescent alcohol initiation
Authors: Zheng Yao , Meyer Zachary , Unger Jennifer B. , Rijsdijk Frühling
Published: February 2023

Following 602 Chinese twin pairs (48% male, all Han ethnicity) from primarily lower‐than‐average socioeconomic status families from early to mid‐adolescence (Ms = 12 and 15 in 2006 and 2009), this study investigated gene–environment interplay between perceived parental supervision, peer drunkenness, and adolescent alcohol initiation. For alcohol initiation, shared environmental influences were initially negligible but became substantial. Genetic factors largely explained the links between both correlates with alcohol initiation. Parental supervision amplified genetic risks for alcohol initiation in early adolescence but suppressed it in mid‐adolescence. Peer drunkenness augmented genetic and environmental influences at both times. Peer drunkenness showed stronger links and moderating potential than parental supervision. Chinese adolescents show dynamic gene–environment interplay patterns involving parent–child and peer processes in alcohol initiation.
Perceived parental alcohol problems and later dropout and grade point average in high school: A register‐based follow‐up study
Authors: Pisinger Veronica Sofie Clara , Møller Sanne Pagh , Andersen Susan , Tolstrup Janne S.
Published: February 2023

Introduction

The aim of the study was to test the hypothesis that young people with perceived parental alcohol problems have higher dropout rates in high school and lower grade point average (GPA) at graduation compared to young people without perceived parental alcohol problems.

Methods

Data come from Danish National Youth Study 2014 (n = 62,171), merged with register‐data on later dropout of high school and GPA. Multilevel Poisson regression models of incidence rates of dropout and multilevel linear models of GPA were used to assess the association with perceived parental alcohol problems.

Results

A total of 6.6% of the students perceived their parent(s) to have alcohol problems. Young people with perceived parental alcohol problems had higher dropout rate (girls incidence rate ratio 1.83; 95% confidence interval [1.62–2.06]); boys (incidence rate ratio 1.38; 95% confidence interval [1.17–1.64]) and lower grades (GPA: −0.24; 95% confidence interval [−0.32; −0.17]) compared to those without. There was no statistically significant difference between mother's and fathers' alcohol problems in the associations with dropout and GPA.

Discussion and Conclusions

Perceived parental alcohol problems were associated with higher incidence rate ratio of dropout and lower grades within all categories of the socioeconomic factors. Our results show that young people with perceived parental alcohol problems have higher high school dropout rates and lower grades compared to those without perceived parental alcohol problems across gender and socioeconomic position. The results call for evidence‐based interventions to support young people with parental alcohol problems in the educational system.
Prediabetes and the risk of type 2 diabetes: Investigating the roles of depressive and anxiety symptoms in the Lifelines cohort study
Authors: Deschênes Sonya S. , McInerney Amy , Nearchou Finiki , Byrne Brendan , Nouwen Arie , Schmitz Norbert
Published: February 2023

Aims

Depression and anxiety may increase the risk of progressing from prediabetes to type 2 diabetes. The present study examined the interactions between prediabetes status and elevated depressive and anxiety symptoms with the risk of type 2 diabetes.

Methods

Participants (N = 72,428) were adults aged 40 years and above without diabetes at baseline from the Lifelines Cohort Study (58% female; mean age = 51.4 years). The Mini‐International Neuropsychiatric Interview screened for elevated symptoms of major depressive disorder and generalized anxiety disorder. Glycated haemoglobin A1c (HbA1c) levels determined prediabetes status at baseline (2007–2013), and HbA1c and self‐reported diabetes diagnoses determined diabetes status at follow‐up (2014–2017). Groups were formed for elevated depressive and anxiety symptoms, respectively, and prediabetes status at baseline (elevated depressive/anxiety symptoms with prediabetes, elevated depressive/anxiety symptoms alone, and prediabetes alone), and compared to a reference group (no prediabetes or anxiety/depression) on the likelihood of developing diabetes during the follow‐up period.

Results

N = 1300 (1.8%) participants developed diabetes. While prediabetes alone was associated with incident diabetes (OR = 5.94; 95% CI = 5.10–6.90, p < 0.001), the group with combined prediabetes and depressive symptoms had the highest likelihood of developing diabetes over follow‐up (OR = 8.29; 95% CI = 5.58–12.32, p < 0.001). Similar results were found for prediabetes and anxiety symptoms (OR = 6.57; 95% CI = 4.62–9.33, p < 0.001), compared to prediabetes alone (OR = 6.09; 95% CI = 5.23–7.11, p < 0.001), though with a smaller effect. The interaction between depressive symptoms and prediabetes was synergistic in age‐and‐sex adjusted analyses.

Conclusions

Individuals with elevated depressive, and to some extent anxiety, symptoms in combination with prediabetes may represent a high‐risk subgroup for type 2 diabetes.
A Lean Approach to Self‐Discovery and Social Innovation
Authors: Hopson Jordan
Published: February 2023

You might be saying, “Hold on, I don't even know what I'm passionate about.”

If you're looking to create positive change, see how the lean process can enable your journey of self‐discovery. Start small, and Build, Measure, and Learn!
Leading by Design in the Twenty‐First Century
Authors: Diwan Anupriya
Published: February 2023

How can design help in the pursuit to empower ourselves, empower others, be co‐creative, and build more internal power?

Improvements to the design process are instrumental in developing solutions for a plethora of wicked problems that humanity faces including creating improved work access for disabled persons.
Decreased β‐hydroxybutyrate and ketogenic amino acid levels in depressed human adults
Authors: Sato Shiho , Yu Zhiqian , Sakai Mai , Motoike Ikuko N. , Saigusa Daisuke , Hirayama Ryo , Kikuchi Yoshie , Abe Takaaki , Kinoshita Kengo , Koshiba Seizo , Tomita Hiroaki
Published: February 2023

β‐hydroxybutyrate (BHB) is a major ketone body synthesized mainly in the liver mitochondria and is associated with stress and severity of depression in humans. It is known to alleviate depressive‐like behaviors in mouse models of depression. In this study, plasma BHB, ketogenic and glucogenic amino acids selected from the Tohoku Medical Megabank Project Community‐Based Cohort Study were analysed and measured using nuclear magnetic resonance spectroscopy. The Center for Epidemiologic Studies Depression Scale (CES‐D) was utilized to select adult participants with depressive symptoms (CES‐D ≥ 16; n = 5722) and control participants (CES‐D < 16; n = 18,150). We observed significantly reduced plasma BHB, leucine, and tryptophan levels in participants with depressive symptoms. Using social defeat stress (SDS) mice models, we found that BHB levels in mice sera increased after acute SDS, but showed no change after chronic SDS, which differed from human plasma results. Furthermore, acute SDS increased mitochondrial BHB levels in the prefrontal cortex at 6 h. In contrast, chronic SDS significantly increased the amount of food intake but reduced hepatic mitochondrial BHB levels in mice. Moreover, gene transcriptions of voltage‐dependent anion‐selective channel 1 (Vdac1) and monocarboxylic acid transporter 1 (Mct1), major molecules relevant to mitochondrial biogenesis and BHB transporter, significantly decreased in the liver and PFC after chronic SDS exposure. These results provide evidence that hepatic and prefrontal mitochondrial biogenesis plays an important role in BHB synthesis under chronic stress and in humans with depressive symptoms.
Brand relationships in wireless mobile environments: The mediating role of apps
Authors: Garcia‐Davalos Alexander , Garcia‐Duque Jorge
Published: February 2023

Brands use branded mobile apps to interact with users and to develop brand relationships in wireless mobile environments. These apps collect data about users and app usage, which are potentially helpful for brand relationship research. We aim to contribute to understanding the user–brand relationship (UBR) measurement mediated by branded apps, an area with very limited research, with a focus on leveraging these apps as a gauging context to measure the UBR strength. We propose a data‐driven model to measure the UBR strength that combines metrics computed by using branded app data with close interpersonal relationship indicators. We conducted a computer simulation to test the proposed model. Our findings show that app usage time is the metric that most affects UBR strength measurement. The results suggest that time is essential for developing brand relationships in wireless mobile environments, much like in interpersonal relationships. The proposed model can be supplemented with other metrics to study new attributes associated with the UBR that might emerge in these environments.
Desirability–doability group judgment framework for the collaborative multicriteria evaluation of public policies
Authors: Bana e Costa Carlos A. , Oliveira Mónica D. , Rodrigues Teresa C. , Vieira Ana C.L.
Published: February 2023

Desirability–doability framework (2 × D) is a novel framework for the collaborative evaluation of public policies. Fundamental objectives and performance indicators are agreed upon in workshops, policies are characterised, and barriers to implementation identified. MACBETH interactive protocols are then applied in decision conferences to elicit qualitative judgments about the desirability of policies, within and across objectives; and about their doability under the expected graveness of barriers on contrasting scenarios. Elicited judgments allow, respectively, to construct a shared multicriteria model measuring the overall desirability of policies; and, to measure their doability. Desirability–doability graphs enable visual interactive classification of policies, with sensitivity/robustness analyses of uncertainties. 2 × D was successfully tested in a real‐world urban‐health policymaking case to evaluate spatial policies. The main novelty of 2 × D is that it bridges the socio‐technical gap, present in OR, between the support required by a complex social decision‐making process, and that usually offered by analytic techniques – while keeping modeling theoretically sound and simple.
Clarification on phase transition behaviors by local strain engineering in Bi1/2Na1/2TiO3–SrTiO3‐based ternary ceramics
Authors: Nguyen Hoang Thien Khoi , Duong Trang An , Ahn Chang Won , Kim Byeong Woo , Han Hyoung‐Su , Lee Jae‐Shin
Published: February 2023

The stabilization of ergodicity plays an important role in realizing large strain in a Bi1/2Na1/2TiO3 (BNT)‐based relaxor, which is strongly related to the degree of random fields with respect to the randomly distributed different cations. To clarify the effects of different ionic radii, this study investigated and compared the microstructures, crystal structures, phase transition behaviors, and electrical properties of BNT–ST‐based ternary ceramics by modifying BiMeO3 (where Me = Al and Fe). It was observed that the stabilized relaxor states are different between BiFeO3‐/and BiAlO3‐modified BNT–ST ternary ceramics. As a result, it is suggested that phase transition (more precisely, the stabilization of ergodicity) can be influenced by the different internal strain in BNT–ST‐based ternary ceramics.
Investigating the impact of a virtual reality mobile application on learners' interpreting competence
Authors: Chan Venus
Published: February 2023

Background

This research is inspired by the challenges encountered in interpreter training, changes in learning needs in the technological era, the educational paradigm shift caused by the COVID‐19 pandemic, the lack of studies on combining virtual reality (VR)_and mobile technologies, and literature gaps in the field of the incorporation of technology in interpreter education.

Objectives

This research aims to develop a mobile‐based VR application for bi‐directional English‐Chinese and Chinese‐English interpreting learning named ‘Virtual Interpreting Practice’ (VIP) based on an interpreting competence model and to investigate its impact on students' self‐rated language and interpreting proficiency levels as well as their declarative knowledge and operative skills as reflected in different interpreting modes (sight and consecutive) and language directions (English‐Chinese and Chinese‐English). The VIP app contains learning resources, including 13 learning modules covering both interpreting modes, practical topics and contexts, video lectures and demonstrations, fully immersive VR and non‐VR practice, glossary lists, source texts, translated texts and an online feedback platform.

Methods

Thirty‐one native Chinese‐speaking English as a second/foreign (ESL/EFL) undergraduate students used the app for self‐directed learning. The data were collected by the pre‐study and post‐study questionnaires as well as the pre‐test and post‐test.

Results and Conclusions

The results indicate that the use of VIP significantly raised the students' self‐rated language and interpreting proficiency levels as well as their interpreting performance in both modes and language directions. While the students performed better in sight interpreting and Chinese‐English interpreting, they achieved a significantly higher improvement rate in consecutive interpreting and English‐Chinese interpreting.
Annual Research Review: Prenatal opioid exposure – a two‐generation approach to conceptualizing neurodevelopmental outcomes
Authors: Conradt Elisabeth , Camerota Marie , Maylott Sarah , Lester Barry M.
Published: February 2023

Opioid use during pregnancy impacts the health and well‐being of two generations: the pregnant person and the child. The factors that increase risk for opioid use in the adult, as well as those that perpetuate risk for the caregiver and child, oftentimes replicate across generations and may be more likely to affect child neurodevelopment than the opioid exposure itself. In this article, we review the prenatal opioid exposure literature with the perspective that this is not a singular event but an intergenerational cascade of events. We highlight several mechanisms of transmission across generations: biological factors, including genetics and epigenetics and the gut–brain axis; parent–child mechanisms, such as prepregnancy experience of child maltreatment, quality of parenting, infant behaviors, neonatal opioid withdrawal diagnosis, and broader environmental contributors including poverty, violence exposure, stigma, and Child Protective Services involvement. We conclude by describing ways in which intergenerational transmission can be disrupted by early intervention.
A Model of Systemic Bank Runs
Authors: LIU XUEWEN
Published: February 2023

We develop a tractable model of systemic bank runs. The market‐based banking system features a two‐layer structure: banks with heterogeneous fundamentals face potential runs by their creditors while they trade short‐term funding in the asset (interbank) market in response to creditor withdrawals. The possibility of a run on a particular bank depends on its assets' interim liquidation value, and this value depends endogenously in turn on the status of other banks in the asset market. The within‐bank coordination problem among creditors and the cross‐bank price externality feed into each other. A small shock can be amplified into a systemic crisis.
Relations between social withdrawal subtypes and socio‐emotional adjustment among Chinese children and early adolescents
Authors: Ding Xuechen , Zhang Wen , Ooi Laura L. , Coplan Robert J. , Zhu Xinyi , Sang Biao
Published: February 2023

The aim of the present study was to compare the relations between subtypes of social withdrawal and socio‐emotional adjustment in Chinese children and early adolescents. Participants included 571 children (Mage = 9.62 years) and 345 adolescents Mage = 12.12 years) in mainland China. Social withdrawal subtypes (i.e., shyness, unsociability, social avoidance) and indices of socio‐emotional adjustment were assessed via self‐reports, peer nominations, and teacher ratings. Shyness tended to be more strongly associated with emotional maladjustment in early adolescence, whereas unsociability was more strongly associated with socio‐emotional difficulties in childhood. For social avoidance, associations with indices of negative adjustment (i.e., social anxiety, emotional symptoms, peer problems) were stronger in childhood, however, associations with indices of positive adjustment (i.e., life satisfaction, well‐being) were stronger in early adolescence.
A perceived control‐relationally devaluing experiences model of low socioeconomic status vulnerability to negative relationship outcomes
Authors: Petsnik Corey , Vorauer Jacquie D.
Published: February 2023

We propose that individuals low (vs. high) in socioeconomic status (SES) are vulnerable to impaired relationship functioning through two different mutually reinforcing paths that both directly implicate perceptions of control and relational devaluation. The first of these involves chronic exposure to relational devaluation as a function of factors such as stigmatization in broader society that serves to undermine low SES individuals’ perceptions of control. The second involves enhanced reactivity to relationally devaluing experiences such as discrimination and ostracism as a function of this limited reserve of perceived control. We present a perceived control‐relationally devaluing experiences model of low SES vulnerability to impaired relationship functioning that incorporates these predictions and further specifies how low SES individuals’ reduced perceptions of control may help account for documented associations between low SES and negative interpersonal outcomes such as hostility, aggression, and reduced relationship quality. We conclude by considering implications for intervention as well as potential alternative and complementary mechanisms.
When I say … Identity
Authors: Sawatsky Adam P. , Monrouxe Lynn V.
Published: February 2023

By appraising the definition of 'identity', Sawatsky and Monrouxe encourage researchers and educators who do professional identity formation work to engage with its rich theoretical tradition.
Plant phenology and species‐specific traits control plant CH4 emissions in a northern boreal fen
Authors: Ge Mengyu , Korrensalo Aino , Laiho Raija , Lohila Annalea , Makiranta Päivi , Pihlatie Mari , Tuittila Eeva‐Stiina , Kohl Lukas , Putkinen Anuliina , Koskinen Markku
Published: February 2023

Aerenchymatic transport is an important mechanism through which plants affect methane (CH4) emissions from peatlands. Controlling environmental factors and the effects of plant phenology remain, however, uncertain.

We identified factors controlling seasonal CH4 flux rate and investigated transport efficiency (flux rate per unit of rhizospheric porewater CH4 concentration). We measured CH4 fluxes through individual shoots of Carex rostrata, Menyanthes trifoliata, Betula nana and Salix lapponum throughout growing seasons in 2020 and 2021 and Equisetum fluviatile and Comarum palustre in high summer 2021 along with water‐table level, peat temperature and porewater CH4 concentration.

CH4 flux rate of C. rostrata was related to plant phenology and peat temperature. Flux rates of M. trifoliata and shrubs B. nana and S. lapponum were insensitive to the investigated environmental variables. In high summer, flux rate and efficiency were highest for C. rostrata (6.86 mg m−2 h−1 and 0.36 mg m−2 h−1 (μmol l−1)−1, respectively). Menyanthes trifoliata showed a high flux rate, but limited efficiency. Low flux rates and efficiency were detected for the remaining species.

Knowledge of the species‐specific CH4 flux rate and their different responses to plant phenology and environmental factors can significantly improve the estimation of ecosystem‐scale CH4 dynamics in boreal peatlands.
Measuring Poverty Dynamics with Synthetic Panels Based on Repeated Cross Sections
Authors: Dang Hai‐Anh H. , Lanjouw Peter F.
Published: February 2023

Panel data are rarely available for developing countries. Departing from traditional pseudo‐panel methods that require multiple rounds of cross‐sectional data to study poverty mobility at the cohort level, we develop a procedure that works with as few as two survey rounds and produces point estimates of transitions along the welfare distribution at the more disaggregated household level. Validation using Monte Carlo simulations and real cross‐sectional and actual panel survey data – from several countries, spanning different income levels and geographical regions – perform well under various deviations from model assumptions. The method could also inform investigation of other welfare outcome dynamics.
Bacteremia following different oral procedures: Systematic review and meta‐analysis
Authors: Martins Carolina C. , Lockhart Peter B. , Firmino Ramon T. , Kilmartin Catherine , Cahill Thomas J. , Dayer Mark , Occhi‐Alexandre Ingrid G. P. , Lai Honghao , Ge Long , Thornhill Martin H.
Published: February 2023

To evaluate the timing, duration and incidence of bacteremia following invasive dental procedures (IDPs) or activities of daily living (ADL). Eight databases were searched for randomized (RCTs) and nonrandomized controlled trials (nRCTs) evaluating bacteremia before and after IDPs or ADL in healthy individuals. The risk of bias was assessed by RoB 2.0 and ROBINS‐I. For the meta‐analysis, the primary outcomes were the timing and duration of bacteremia. The secondary outcome was the incidence of bacteremia, measuring the proportion of patients with bacteremia within 5 min after the end of the procedure compared with baseline. We included 64 nRCTs and 25 RCTs. Peak bacteremia occurred within 5 min after the procedure and then decreased over time. Dental extractions showed the highest incidence of bacteremia (62%–66%), followed by scaling and root planing (SRP) (44%–36%) and oral health procedures (OHP) (e.g., dental prophylaxis and dental probing without SRP) (27%–28%). Other ADL (flossing and chewing) (16%) and toothbrushing (8%–26%) resulted in bacteremia as well. The majority of studies had some concerns RCTs or moderate risk of bias nRCTs. Dental extractions, SRP and OHP, are associated with the highest frequency of bacteremia. Toothbrushing, flossing, and chewing also caused bacteremia in lower frequency.
Transferring measurable residual disease measurement in pediatric acute lymphoblastic leukemia from quantitative real‐time PCR to digital droplet PCR
Authors: Luib Luise , Kreyenberg Hermann , Michaelis Sebastian , Handgretinger Rupert , Mezger Markus
Published: February 2023

Background

Since the measurement of measurable residual disease (MRD) is part of clinical routine examination for children affected with acute lymphoblastic leukemia (ALL), continuous efforts are made to improve its method, applicability and accuracy. Whereas quantitative real‐time polymerase chain reaction (qPCR) is considered as the gold standard for MRD detection and endowed with international guidelines for implementation and evaluation, these do not yet exist for digital droplet PCR (ddPCR). However, advantages are seen in droplet partitioning for MRD measurement to allow absolute quantification without depending on reference samples.

Methods

In this study, 17 MRD targets of nine patients with childhood B‐ALL were analyzed with qPCR and ddPCR, respectively. All patients were assigned to high risk group and had hematopoietic stem cell transplantation and CD19 antibody therapy for relapse prevention. Starting with the sequences and guidelines of qPCR and optimizing the protocol for ddPCR, the MRD targets could also be measured precisely with this novel method, using the same primer and probe sets as for qPCR.

Results

The already established MRD protocol of qPCR could be transferred to ddPCR and all 17 MRD targets were measured in dilution series reaching comparable Limit of detection levels with both PCR methods.

Conclusions

With a given qPCR protocol and some experience in conventional MRD monitoring, it is conceivable to transfer the procedure of MRD measurement to ddPCR technology. Our data is in line with other studies which are summarized and discussed here as well to facilitate the transfer of MRD diagnostics to ddPCR.
Perspectives of oral health therapists on the barriers to oral care provision in nursing homes in Singapore: A qualitative analysis
Authors: Ho Shenna Yu‐En , Walsh Laurence James , Pradhan Archana , Yang Jingrong , Lopez Silva Claudia Patricia
Published: February 2023

Introduction

Oral health therapists (OHTs) are a valuable resource for increasing access to dental care for the frail elderly in nursing homes (NHs). However, OHTs face several barriers and their skill‐set continues to be under‐utilized.

Aims

To evaluate the perceptions of OHTs regarding the barriers towards oral care provision for the elderly residents in NHs.

Methodology

Semi‐structured interviews were conducted with 11 OHTs to discuss the factors that may hinder them from providing oral health services in NHs. An inductive thematic analysis directed by the grounded theory approach was performed.

Results

Four major themes emerged: (i) lack of opportunity, (ii) lack of adequate education and training, (iii) limited work scope and registration status, and (iv) lack of adequate financial remuneration and adequate equipment. OHTs also raised the lack of awareness among OHTs and the various stakeholders, of how the skill‐set of OHTs may be relevant for oral care provision in NHs.

Conclusion

Findings revealed underlying educational and regulatory barriers which need to be addressed in tandem. Addressing these barriers can be impactful in informing future strategies for the greater utilization of the skill‐set of OHTs in Singapore.
Activity distribution among the hamstring muscles during high‐speed running: A descriptive multichannel surface EMG study
Authors: Suskens Jozef J. M. , Tol Johannes L. , Kerkhoffs Gino M. M. J. , Maas Huub , van Dieën Jaap H. , Reurink Gustaaf
Published: February 2023

Purpose

This study assessed activity distribution among the hamstring muscles during high‐speed running. The objective was to compare within and between muscle activity, relative contribution and hip and knee joint angles at peak muscle activity during high‐speed running.

Methods

Through multichannel electromyography, we measured muscle activity in male basketball players during high‐speed running on a treadmill at 15 locations: five for biceps femoris long head, four for semitendinosus, and six for semimembranosus. Muscle activity was calculated for each location within each hamstring muscle individually for each percent of a stride cycle.

Results

Twenty‐nine non‐injured basketball players were included (mean age: 17 ± 1 years; mass, 85 ± 9 kg; height, 193 ± 9 cm). Heterogeneous activity was found for all individual hamstring muscles across multiple events of the stride cycle. In the late‐swing phase, muscle activity and relative contribution of the semimembranosus was significantly higher than of the semitendinosus. There was no significant difference in hip and knee joint angles at instant of peak muscle activity, assessed locally within individual hamstring muscles, as well as in general over the whole hamstring muscle.

Conclusion

Hamstring muscles were most active in the late‐swing phase during high‐speed running. In this phase, the semimembranosus was most active and the semitendinosus was least active. Within the biceps femoris long head, the most proximal region was significantly more active in the late‐swing phase, compared to other muscle regions. For each muscle and location, peak muscle activity occurred at similar hip and knee joint angles.
Interface Capturing Flow Boiling Simulations in a Compact Heat Exchanger
Authors: Iskhakova Anna , Kondo Yoshiyuki , Tanimoto Koichi , Dinh Nam T. , Bolotnov Igor A.
Published: February 2023

High-fidelity flow boiling simulations are conducted in a vertical mini channel with offset strip fins (OSF) using R113 as a working fluid. Finite-element code PHASTA coupled with level set method for interface capturing is employed to model multiple sequential bubble nucleation using transient three-dimensional approach. The code performance is validated against experiments for a single nucleation site in a vertical rectangular channel. To assess code performance, a study on the bubble departure from the wall in a mini channel with OSF is carried out first. Contributions from the microlayer are not considered due to low heat flux values applied to the channel (1 kW/m2). The influence of surface characteristics, such as contact angle and liquid superheat on bubble dynamics, is also analyzed as well as the local two-phase heat transfer coefficient. For higher void fractions, two conical nucleation cavities are introduced in the same channel with OSF. Observed bubble characteristics (departure diameter, bubble departure frequency) are evaluated and bubble trajectories are presented and analyzed. The local heat transfer coefficient is then evaluated for each simulation. The results show approximately a 2.5 time increase in the local heat transfer coefficient when the individual bubbles approach the wall. With smaller bubble nucleation diameters, the heat transfer coefficient can increase by up to a factor of two. Thus, the current work demonstrates the flow modeling capability of the boiling phenomena in complex geometry with OSF.
Probabilities of Agreement for Computational Model Validation
Authors: Ledwith Matthew C. , Hill Raymond R. , Champagne Lance E. , White Edward D.
Published: February 2023

Determining whether a computational model is valid for its intended use requires the rigorous assessment of agreement between observed system responses of the computational model and the corresponding real world system or process of interest. In this article, a new method for assessing the validity of computational models is proposed based upon the probability of agreement (PoA) approach. The proposed method quantifies the probability that observed simulation and system response differences are small enough to be considered acceptable, and hence, the two systems can be used interchangeably. Rather than relying on Boolean-based statistical tests and procedures, the distance-based probability of agreement validation metric (PoAVM) assesses the similarity of system responses used to predict system behaviors by comparing the distributions of output behavior. The corresponding PoA plot serves as a useful tool for summarizing agreement transparently and directly while accounting for potentially complicated bias and variability structures. A general procedure for employing the proposed computational model validation method is provided which leverages bootstrapping to overcome the fact that in most situations where computational models are employed, one’s ability to collect real world data is limited. The new method is demonstrated and contextualized through an illustrative application based upon empirical data from a transient-phase assembly line manufacturing process and a discussion on its desirability based upon an established validation framework.
Integration of Data Science Into Thermal-Fluids Engineering Education
Authors: Hu Han , Heo Connor
Published: February 2023

To improve the integration of data science into thermal fluids education, a technical elective course is developed to introduce a wide range of machine learning and deep learning algorithms to engineering students, including principal component analysis, multiplayer perceptron, convolutional neural networks (CNN), long short-term memory (LSTM) networks, reinforcement learning (RL), generative algorithms (GA), and generative adversarial networks for mechanical engineering applications, including visualization-based physical quantity predictions, dynamic signal classification, and prediction, data-driven control of dynamical systems, surrogate modeling, dimensionality reduction, among others. The lectures cover the fundamental concepts and examples of developing machine learning models using Python and MATLAB. To facilitate students’ practice of applying data science in solving mechanical engineering progress, this course has touchpoints in several key areas of mechanical engineering, including fluid mechanics, heat transfer, materials science, design, and dynamics/control. Twenty-five students, including seven undergraduate and eighteen graduate students, took the course and the outcomes are very fruitful and encouraging. A variety of data science algorithms have been leveraged to solve mechanical engineering research problems, including generative designs of air-cooled heat sinks, Gaussian process regression for battery lifetime prediction and femtosecond laser manufacturing parameters, GA for two-phase cooling heat exchanger design, coupled PCA and LSTM for microcapsule deformation prediction, CNN for boiling regime classification and laser-manufactured textures classification, bidirectional recurrent neural networks basecalling of DNA and RNA sequences, coupled PCA and MLP porous medium morphology classification, RL for the control of soft robotics. The course has so far led to 25 student-centered machine learning projects, two conference papers, and an Honors thesis.
Characterization of Additively Manufactured Metals from ADDere Printing
Authors: Foster Joshua , Kumpaty Subha , Coen Liam , Perkins Al , Gengler Michael , Woida Scott
Published: February 2023

Midwest Engineered Systems Inc. has created a novel laser wire metal deposition process, ADDere manufacturing. ADDere has a much higher deposition rate than powder bed fusion, making it ideal for large components. In this project, the mechanical properties of ADDere printed materials were tested and compared to typical values found in ASM publications to show the quality of materials manufactured by the ADDere printing process. A detailed material analysis was performed on samples made from Ti-6Al-4V and 17-4 PH stainless steel. This work builds upon an earlier study of samples made from 17-4 PH that were produced using a single direction pattern. In this project, the 17-4 PH samples were printed in a cross hatched pattern, and testing results were compared to existing data from single direction samples of the previous research. The Ti-6Al-4V samples were created in two builds. One using the unidirectional method and the other with the crossed pattern. Testing specimens were removed from the samples using a water jet cutter and further machined into ASTM tensile bars and metallurgic mounts to perform a thorough material evaluation. The Ti-6Al-4V sample met the expected values in the ASM literature, and the cross hatched 17-4 PH exhibited a higher hardness and better microstructure than the single direction samples from the previous work. It was also observed that when the Ti64 samples were manufactured in the cross hatched pattern, the properties indicated slight improvement and more homogeneity than those printed in single layer direction. The obtained results indicate that ADDere’s printing process can produce highly refined materials that are customizable with their expected uses. This work showcases an excellent industry collaboration of an undergraduate research experience.
Effect of Curing Parameters on Warp in the SLA Printing Process
Authors: Schmitz Anne
Published: February 2023

Heat during the ultraviolet (UV) curing step of stereolithographic (SLA) printing can affect dimensional accuracy. The goal of this study was to quantify how curing affects warp. Six warp curtain specimens were printed out of a Draft material using a Form 2 SLA printer. After printing, the specimens were washed in isopropyl alcohol to remove any uncured resin. Two of the specimens were left uncured after the washing step. Two of the specimens were cured with no heat and two specimens cured with heat. Next, a high-resolution camera was used to take a picture of each specimen and digitize five layers. A line was fit to each horizontal set of points and used to calculate a warp index. Curing significantly decreased warp between the non-cured specimen and specimen cured with no heat by 0.16 (p = 0.023). The specimen cured with heat was also lower than the uncured specimen by 0.18 (p = 0.017). No difference was observed in warp between the specimens cured with or without heat (p = 0.758). However, these changes in warp did not prove practically significant as the differences were less than the minimal detectable change (MDC) of the system. The warp indices were found to be less than 1 in all specimens, smaller than the literature on warp in polyamide (PA) of up to 4. Warp in these SLA parts is likely small since there is no uneven heating between layers during the printing process.
Coupling Sampling-Based Tolerance-Cost Optimization and Selective Assembly – An Integrated Approach for Optimal Tolerance Allocation
Authors: Roth Martin , Seitz Markus Johannes , Schleich Benjamin , Wartzack Sandro
Published: February 2023

Optimization has gained increased attention in product development and is nowadays profitably used to solve complex design problems. In tolerance design, tolerance-cost optimization is a systematic and efficient approach to allocate part tolerance values in a cost-optimal way. The usage of sampling-based tolerance analysis techniques thereby enables the consideration of machine-specific part tolerance distributions as well as individual batch sizes and thus facilitates a concurrent allocation of tolerances and machines. With the aim to further exploit its potential by embedding assembly aspects, this article presents a novel approach combining tolerance-cost optimization and optimal selective assembly. Based on an initial introduction of its general idea, a global optimization problem is defined to simultaneously identify the best combination of tolerance values, machines with their batch sizes and sorting orders of the individual batches. Subsequently, its solution using metaheuristic optimization algorithms and mixed-integer variables is presented. The theoretical findings are finally confirmed by its exemplary application to a use case indicating that it can reveal hidden cost improvement potentials in tolerance design.
Analysis of Grinding Parameters in Machining IBR of Aero-Engine
Authors: Zhao T. , Shi Y. Y. , Zhang Z. Q. , Pu Y. S. , He Z.
Published: February 2023

Ti-6Al-4V alloy is widespread applied in aero-engine components, such as blisk and blades. The surface quality of these components has a remarkable impact on aero-engine in aerodynamic performance and service life. Residual stress and surface roughness are considered as the most representative parameters for evaluating the surface quality. Therefore, in order to analyze the effect of grinding parameters on surface quality and improve the surface quality of components, the grinding parameters, including wheel rotational speed, feed rate, processing depth and abrasive size, were choose, and the influence of each parameter on surface roughness and residual stress were investigated. Besides, the grey relational grade analysis was used to analyze grinding parameters. Finally, through verifying the optimization results, the optimal processing parameters for grinding Ti-6Al-4V alloy were obtained. The results reveals that the surface quality of blade has been improved greatly (73.9% reduce in surface roughness and 26.3% increase in residual stress).
Flame Propagation Analysis of Anhydrous and Hydrous Ethanol in an Optical Spark Ignition Engine
Authors: Pinheiro-Martins Fernanda , Teixeira Lacava Pedro
Published: February 2023

The present study aims to evaluate the intrinsic differences in in-cylinder combustion in low load and low-speed conditions by applying experimental and numerical techniques. The experimental apparatus consisted of an AVL5406 SI-PFI single-cylinder with optical access operating under two different fuel delivery methods: Port Fuel Injection (PFI) and Direct fuel Injection (DI) with anhydrous ethanol (E100) and hydrous ethanol (E96W4).

The outcomes of the engine-like conditions tests were evaluated based on the quantitative analysis of the flame propagation and on the thermodynamic data obtained using INDICOM. A Video Scope VS4-1845HS high-speed camera providing cycle resolved UV-visible digital image captured the natural emission of the flame for each test. Forthwith image acquisition, the flame propagation characteristics were post-processed through image segmentation techniques. Finally, relevant literature was revised to support the results and findings obtained at this time.

The contribution of this study to the internal combustion engines research remains in gathering more information about in-cylinder flame front propagation and combustion stability for E96W4 and E100 ethanol under partial load and stoichiometric and lean conditions.
Electrohydrodynamic Conduction Pumping Driven Flow and Heat Transfer in a Flexible Minichannel
Authors: Ramachandran Deepak Selvakumar , Lee Hyoungsoon
Published: February 2023

Numerical investigation of electrohydrodynamic (EHD) conduction pumping driven fluid flow and heat transfer in a flexible minichannel has been performed. The two-way coupled set of governing equations for fluid flow, heat transfer, electric potential, and charge transport are programmed into the existing finite-volume framework of OpenFOAM. A two-species charge transport model which considers the field-enhanced dissociation due to Onsager-Wien effect has been adopted. The ability of EHD conduction pumping mechanism to induce flow in straight and curved configurations of a minichannel are demonstrated. The flow and heat transfer characteristics are quantified in terms of mean velocity, maximum velocity, maximum wall temperaturen and mean Nusselt number. Even at low applied voltages (≤ 1kV), EHD conduction pumping is able to induce flow and heat transfer in the minichannel, in both the configurations. At 1kV applied voltage, the fall in heat transfer in 90° bent configuration is only 4%, as compared to that in the straight minichannel. Results of this study reveal that EHD conduction based pumping is a viable option in flexible minichannel heat sinks.
Maintenance Centered on Exergy and Exergoeconomic Indicators of a Preheat Train of a Crude Oil Distillation Unit
Authors: Fajardo Juan , Negrette Camilo , Cardona Camilo , Yabrudy Daniel , Barreto Deibys
Published: February 2023

Established or create new ones to plan the cleaning tasks of the heat exchangers. In this work, a maintenance strategy is developed for a preheating train under the Maintenance Centered on Energy Efficiency (MCEE) philosophy, where it is sought to integrate the information of the principles of the second law of thermodynamics with economic variables to use parameters. The modification of the maintenance justification parameter (J) is proposed, adding to the introduction of two new maintenance indicators (W and X). Each one seeks to evaluate an essential criterion for the maintenance area: economic viability, technical feasibility, and benefits. Towards the other exchangers in the network after cleaning a specific component. A criticality diagram and a criticality matrix are used. The heat exchangers are grouped into sub-assemblies, with the leading group consisting of the key heat exchangers (KHEX), the elements of which have a significant impact on the efficiency of the preheat train. For their part, the regions are composed of components whose performance is less considerable than that of the KHEX. In total, 34 maintenance activities will be carried out, distributed among the 25 interchanges of the network. The planning of a program of cleaning activities according to the maintenance strategy based on the philosophy of the MCEE establishes a substantial scientific contribution due to the almost null existence of exergetic studies applied to the management of maintenance tasks and focused mainly on the preheating of trains.
Innovations for Clutching and Shifting in Formula-Style Drivetrains
Authors: Pokharel Pranaya , Rowland Jacob , Snyder Trevor , Gonzalez Luis
Published: February 2023

This project’s objective was to design an automated electronic clutching and mechanical shifting system for a formula-style car which is a part of the ergonomics and drivetrain sub-systems. The Formula Society of Automotive Engineers (FSAE) at Midwestern State University (MSU) approved this project to be part of the design and manufacturing of their first-generation vehicle. The shifter and clutch designs meet the requirement for the Senior Design project. Past designs by various teams have demonstrated a variety of methods of clutch actuation and gear shifting. A popular design amongst most teams is paddle shifting and direct clutch actuation. The design calls for electric push buttons on the backside of the steering wheel that allows the driver to manipulate the solenoids needed to manually cycle through the gears. The current study proposes a semi-automatic clutching system together with a mechanical gear shifting system.

Initial brainstorming led to the idea to combine the clutch with the gas pedal. The concept is that if the pedal is pushed down to a certain angle it will release the clutch, allowing the gears engagement. Meaning when the pedal is not depressed the clutch remains engaged disconnecting the drivetrain. The proposed clutching system utilizes a rotary position sensor, a servo motor, and a communication system between the two. The major idea is to integrate the sensor on the gas pedal so that it senses the position of the pedal. The output from the sensor is communicated by the use of a logic unit to a servo motor attached to the clutching lever of the engine. As the gas pedal is pressed the sensor sends a signal to the servo motor to actuate the clutch accordingly, removing the need for a separate clutch pedal. The Arduino is utilized to relay the signal from the position sensor to the servo motor. The gear shifting mechanism is mechanically operated using a shifter that is connected to a solid rod that actuates the gear selector on the engine. The rod selected is an all thread rod wrapped in Nylon, and the shifting lever is a simple pivot type. This system is completely designed and is implemented in the SAE vehicle. Successful implementation demonstrated the usefulness of the system over traditional clutching and shifting systems. Two major advantages of this system are the elimination of a clutch pedal and the longevity of the gearbox. The steps included a significant amount of brainstorming and taking some important decisions together with the instructor.

The team also gained significant experience to employ engineering solutions in an organized manner. As per the author’s knowledge, the proposed design is a novel concept for use in FSAE cars. During the process, the students entirely came up with this idea themselves. Successful completion showed that the students learned to innovate new designs and concepts for a part of a formula-type vehicle using the gained engineering knowledge.