bluuebunny/crossref_metadata_2025 huggingface dataset:
Gender-Based Analysis of the Association Between Mental Health, Sleep Quality, Aggression, and Physical Activity Among University Students During the COVID-19 Outbreak
Authors: Vuelvas-Olmos César Rubén , Sánchez-Vidaña Dalinda Isabel , Cortés-Álvarez Nadia Yanet
Published: April 2022

COVID-19 has spread throughout the world, resulting in significant morbidity, mortality, and negative psychological effects among general population. However, university students are particularly vulnerable in terms of mental health. The present study evaluated the association between mental health, quality of sleep, aggression, and physical activity in university students in Mexico after 1 year of dealing with the COVID-19 pandemic in Mexico, including a gender-sensitive analysis. Participants (935 university students) completed an online questionnaire which collected information regarding demographic data, psychological distress (IES-R scale), depression, anxiety, and stress (DASS-21), aggressiveness Buss-Perry Aggressive Questionnaire, sleep quality (PSQI) and physical activity (IPAQ-S). Findings showed that female students showed significantly higher scores in psychological distress, anxiety, stress scores and sleep quality, as compared to male students. By contrast, male students showed significantly higher scores on aggressiveness than female students. In addition, on physical activity, females performed significantly higher MET-min/week on moderate and high levels. Finally, liner regression model accounted for approximately 73.5% of the variance in DASS-21 scores, with the body mass index, IES-R, Pittsburgh Sleep Quality Index, and IPAQ subscales, emerging as significant individual (positive) predictors. Therefore, the pandemic affected female and male students differently. Female students reported more psychological distress, anxiety, and stress while male students reported higher aggressiveness. The differences observed may be due to physiological differences, the response to stress, and differences in sensitivity to life events.
Social and religious dimensions of mixed-faith families: The case of a Muslim–Christian family
Authors: Arweck Elisabeth
Published: April 2022

The article reports data from a study investigating the religious identity formation of young people in mixed-faith families. This involved parents from Christian, Hindu, Sikh, and Muslim backgrounds, with a spouse of these four faiths. One of the ‘Muslim–non-Muslim’ families is considered here as a case study to shed light on social and religious dimensions pertaining to both parents and children. One parent has a Muslim, the other a Christian background. The article examines how the parents understand and approach the ‘mixed’ nature of their family and how this translates into socialising their children into their respective religious traditions. It also engages with the perceptions of the children, exploring their sense of religious identity and social belonging. Drawing on interviews, the article discusses participants’ perspectives regarding ‘dual heritage’/‘mixedness’ and cultural and religious transmission, referring to studies on mixed-faith families to embed the data in existing research.
Maximizing Learning Opportunities with Young Refugee Multilingual Learners in Urban Schools: An Asset-Based Participatory Action Research
Authors: Hong Huili
Published: April 2022

This paper reports an asset-based participatory research study with 18 pre-service teachers and 85 refugee multilingual learners in an after-school program housed in an urban public elementary school. The research illuminates how the refugee multilingual learners (RMLs)’ backgrounds, assets, and challenges can be understood and transformed to maximize their learning opportunities. The findings provide a renewed perspective on RML students and alternative pedagogical approaches with the hope of improving their learning experiences and outcomes. The findings also call for continuous teachers’ professional training concerning RMLs’ diverse backgrounds, knowledge, and experiences. This paper concludes with a promising concept, cultural humility, in urban education research.
Urban Education on Engaging Communities and Supporting Praxis with Immigrant and Refugee Families
Authors: Hong Huili , da Silva Iddings Ana Christina
Published: April 2022

The COVID-19 pandemic has exacerbated the U.S. government's recent harsh restrictions on immigrants and refugees and the ramped-up anti-immigrant sentiments. The strict borderlands politics, the militarized police at the border zones, family separations and other tactics of fear, silencing, and oppression reinforced within public spheres and institutions (e.g., racialized policies of control, the constant threat of deportation) have greatly impacted the lives of immigrant and refugee families and children ( Gándara & Ee, 2018 ; Zayas et al., 2015 ). Providing sociopolitical, educational, and emotional support for immigrant/refugee students and their families has never become so urgent during this extraordinary time.
Learning in Dialogue with Latinx Children of Immigrants: Reflections on the Co-emergence of Collaborative Linguistic Inquiry and Critical Pedagogical Praxis
Authors: Martínez Ramón Antonio , Martinez Danny C.
Published: April 2022

In this article, we recount our experiences learning from and with Latinx children of immigrants in urban schools. Highlighting how insights gleaned from our respective ethnographic projects have led us to embrace more explicit commitments to participatory engagement, we consider how young people's perspectives can and should fundamentally shift adults’ understanding of their communicative practices and linguistic ingenuity. We end by articulating a utopian vision for educational ethnography and language education in urban schools, one characterized by multidirectional and intergenerational learning, and in which critical pedagogical praxis emerges as researchers and teachers engage in dialogue with Latinx children of immigrants.
Facilitating Educational Equity and Safety of Undocumented Immigrant Students
Authors: da Silva Iddings Ana Christina , Warraich Axa Khalid
Published: April 2022

Immigration policies and deportations have negatively impacted not only undocumented immigrant students and their families, but also their teachers, administrators, counselors, and other community members. Drawing on Freire’s (1970) concept of praxis, and on critical-ecological educational approaches (da Silva Iddings, 2017), we interviewed educators to better understand the possibilities of partnerships between university-schools-communities to collaboratively facilitate educational equity and safety of undocumented immigrant students in U.S. schools . Thus, this article aims to shed light on ways to respond to the current sociopolitical and educational issues these students are facing and on ways to improve their schooling experiences.
“Leaning In” or “Taking a Knee”: Career Trajectories of Senior Leaders in the Canadian Armed Forces
Authors: Coulthard Julie , Wright Justin
Published: April 2022

Less research has examined the extent to which external contexts and factors that influence an organizational member’s life choices also influence their career trajectories within the military, and particularly among those who advance to leadership positions at the General Officer/Flag Officer level. Interviews were conducted with 20 select General Officer/Flag Officers in the Canadian Armed Forces. As part of a secondary analysis of an exploratory qualitative study, we applied a Life Course Theory lens to better understand the intersections between the sociohistorical and cultural context of senior leader development, and the individual choices that the participants made that led to their ascent to their rank. This study provides insight into how the historical time and place, the timing in their lives, the linked lives they share with family, and the degree of agency they maintained over their life choices led participants to “lean in” rather than “take a knee.”
Clinical Predictors of OSA Treatment Success Following Implantation of a Hypoglossal Nerve Stimulation Device
Authors: Boroosan Avrahan , Salapatas Anna M. , Friedman Michael
Published: April 2022

Objective

To identify prognostic indicators associated with successful hypoglossal nerve stimulation (HGNS) therapy to treat obstructive sleep apnea (OSA), focusing on patients’ physiologic response to awake tongue protrusion.

Study Design

Retrospective chart review.

Setting

Tertiary care center.

Methods

We included consecutive patients with moderate‐severe OSA who underwent HGNS implantation from December 2017 to December 2019. Data abstracted include standard demographics, body mass index (BMI), pre‐ and postoperative apnea‐hypopnea index (AHI), and Friedman tongue position (FTP). Additionally, change in hypopharyngeal cross‐sectional area on awake tongue protrusion was abstracted. Patients protruded their tongues, and the physician visualized change. Positive change in hypopharyngeal cross‐sectional area was documented as +1 and a negative change as −1. Chi‐square tests for independence and logistic regression analysis were performed to determine indicators of successful surgery.

Results

Thirty‐nine patients were included in this study. Mean ± SD AHI decreased significantly from 43.1 ± 17.36 to 9.18 ± 8.18. Surgical success was achieved in 79.5% of patients. Variables analyzed included BMI >32, preoperative AHI, FTP, and change in hypopharyngeal cross‐sectional area on awake tongue protrusion (positive, 65.8%; negative, 34.2%). Positive predictors of success were positive change in hypopharyngeal cross‐sectional area (P =. 0133), severe OSA (P =. 0290), and FTP IIb (P <. 0001). Negative predictors were BMI >32 (P =. 041) and negative change in hypopharyngeal cross‐sectional area (P =. 02).

Conclusion

Positive change in hypopharyngeal cross‐sectional area on awake tongue protrusion and severe baseline AHI were positive predictors of successful HGNS therapy. Negative change in hypopharyngeal cross‐sectional area on awake tongue protrusion and BMI >32 were negative predictors.
Transformational Leadership During the COVID-19 Pandemic: Strengthening Employee Engagement Through Internal Communication
Authors: Santoso Nobertus R. , Sulistyaningtyas Ike D. , Pratama Brahma P.
Published: April 2022

This article examines the function of transformational leadership in enhancing employee engagement through internal communication during the COVID-19 pandemic to ensure the companies’ sustainability. This article is based on semi-structured interviews with 16 informants (human resources department representatives and employees) from the four industries most impacted by the COVID-19 epidemic: travel, hotel, food and beverage, and retail sectors. The findings reveal that transformational leaders play a critical role in fighting the COVID-19 pandemic by encouraging employees to be innovative and creative, undertaking active actions, and strengthening employee engagement through internal communication. On the other hand, internal communication has changed due to the pandemic, including communication flow, messages, and media. Internal communication has promoted a climate for active communication behaviors encouraging knowledge sharing, collaboration, and creativity-enhancing employee engagement. Through spiritual values, transformational leaders who promote employee engagement amid this crisis ensure the organization's sustainability. Due to the COVID-19 pandemic, this research suggests that leaders might increase employee engagement by including spiritual values through internal communication.
After-care, resettlement and social inclusion: The role of probation
Authors: Canton Rob
Published: April 2022

The priority of public protection has moved probation away from its historical concerns with providing after-care, now emphasising risk management as well as the continuation of the sentence in the community. Yet people released from prison notoriously face many difficulties in accessing the social resources they need for desistance and meet with mistrust associated with their criminal records. This paper looks at the responsibilities of the Probation Service in their supervision of people leaving prison, considering the role of probation in promoting social inclusion and supporting desistance.
What if I Don’t Like All of Them? A Person-Centered Approach to Examine Student–Teacher Relationships in the First Year of Secondary School
Authors: Roorda Debora L. , Bosman Rianne J.
Published: April 2022

Person-centered analyses were used to identify relationship profiles based on seventh graders’ perceptions of relationships with three of their teachers (homeroom teacher, teacher of the easiest subject, teacher of the hardest subject). Furthermore, we investigated whether students’ characteristics (gender and academic track) could explain relationship profile membership and how these relationship profiles were associated with students’ school engagement. Students ( N = 899, 47.8% girls) reported about their relationships (closeness, conflict) with their teachers. Students and their homeroom teachers reported about students’ behavioral and emotional engagement. Four relationship profiles were found: a no risk profile (high closeness, low conflict with all three teachers), two single risk profiles (low closeness, high conflict with only one teacher), and one multiple risk profile (high conflict with all three teachers). Furthermore, boys were underrepresented in the no risk profile. Finally, students in the no risk profile tended to be more behaviorally and emotional engaged.
Spinal metastasis: narrative reviews of the current evidence and treatment modalities
Authors: Jaipanya Pilan , Chanplakorn Pongsthorn
Published: April 2022

The treatment for spinal metastasis has evolved significantly during the past decade. An advancement in systemic therapy has led to a prolonged overall survival in cancer patients, thus increasing the incidence of spinal metastasis. In addition, with the improved treatment armamentarium, the prediction of patient survival using traditional prognostic models may have limitations and these require the incorporation of some novel parameters to improve their prognostic accuracy. The development of minimally-invasive spinal procedures and minimal access surgical techniques have facilitated a quicker patient recovery and return to systemic treatment. These modern interventions help to alleviate pain and improve quality of life, even in candidates with a relatively short life expectancy. Radiotherapy may be considered in non-surgical candidates or as adjuvant therapy for improving local tumour control. Stereotactic radiosurgery has facilitated this even in radioresistant tumours and may even replace surgery in radiosensitive malignancies. This narrative review summarizes the current evidence leading to the paradigm shifts in the modern treatment of spinal metastasis.
Exploring the experiences of individuals living with persistent pain using a visual art diary
Authors: Lou Jasmine , Pourkazemi Fereshteh , Mackenzie Lynette
Published: April 2022

Introduction

Persistent pain significantly impacts daily living. Visual arts interventions can have positive outcomes, but little is known about benefits for people with persistent pain. This study aimed to explore participant experiences of utilising visual art in expressing and managing their persistent pain experience through a visual diary.

Method

As part of a small exploratory study nested in a larger project, participants with a history of persistent pain were recruited from a local pain management clinic. Six participants with persistent pain attended five weekly intervention sessions involving art observation, creation and discussion, at the Art Gallery of NSW. Participants explored their ideas about their pain experience through artmaking using visual and written data from self-reported pain diaries. Thematic analysis was used.

Results

Analysis of five diaries was conducted. Visual and written expressions of the pain experience varied. Colour was used by participants to represent ideas and emotions. Capital letters were used to convey tone, or emphasis. Three main themes emerged from the written and visual data: ‘The lived experience of pain’, ‘The powerful drive for growth beyond change itself’ and ‘Personal values and perceptions guiding daily living and decision-making’.

Conclusion

This study provides insights into the potential benefits of using visual arts to help manage persistent pain experiences and improve health outcomes.
The Gendered Consequences of Risk-Taking at Work: Are Women Averse to Risk or to Poor Consequences?
Authors: Morgenroth Thekla , Ryan Michelle K. , Fine Cordelia
Published: April 2022

Women are seen as more risk-avoidant in the workplace, and some have argued that this contributes to occupational gender gaps. Across two correlational and three experimental studies (total N = 2280), we examined the role of consequences of workplace risk-taking in determining the likelihood of taking future risks at work. We found no evidence for overall gender differences in initial risk-taking, and women and men anticipated similar consequences for risks with which they have no experience. However, this stands in contrast to the consequences of risk-taking they have experienced. Here, men reported on average more positive consequences, even for those risks that are more normative for women, translating into a higher likelihood of taking the same risks again. When faced with the same consequences, women and men were equally likely to take the same risks again. Our findings challenge the simple assumption that women are averse to workplace risks and suggest that if and when women do avoid risks, it is because their risk-taking leads to less rewarding consequences. Workplace gender equality initiatives should therefore tackle any inequities of consequences rather than encouraging women to “lean in” and take more risks. Additional online materials for this article are available on PWQ’s website at https://journals.sagepub.com/doi/suppl/10.1177/03616843221084048 .
Perspectives on Aging and End of Life Among Lower Socioeconomic Status (SES) Older Adults
Authors: Coogan Anne , Kimpel Christine , Jones Abigail C. , Barroso Julie , Frechman Erica , Maxwell Cathy A.
Published: April 2022

Objective: To explore the experiences of aging that influence perceptions of and receptivity to planning for aging and EOL among lower SES older adults. Methods: Supported by a frailty-focused communication educational aid, semi-structured interviews were conducted with 20 older adults residing in income-assisted housing. Follow-up interviews were conducted 2 weeks later. Descriptive content analysis was performed. Results: Participants mean age was 62.4, and 75% were African American. Six categories emerged to create a narrative of lower SES older adults’ experiences, including (1) readiness to plan for aging and EOL, (2) interaction with the healthcare system, (3) daily life with insufficient resources, (4) the role of religiosity, (5) relationships with others, and (6) motivation and health status. Discussion: Life course vulnerabilities and struggles of lower SES older adults preclude opportunities to proactively plan for aging and EOL. Holistic interventions and innovative approaches are needed to address aging across the life course.
Hospital Academic Status and the Volume-Outcome Association in Postoperative Patients Requiring Intensive Care: Results of a Nationwide Analysis of Intensive Care Units in the United States
Authors: Naar Leon , Maurer Lydia R. , Dorken Gallastegi Ander , El Hechi Majed W. , Rao Sowmya R. , Coughlin Catherine , Ebrahim Senan , Kadambi Adesh , Mendoza April E. , Saillant Noelle N. , Renne B. Christian B. , Velmahos George C. , Kaafarani Haytham M.A. , Lee Jarone
Published: April 2022

Objective: To determine whether the outcomes of postoperative patients admitted directly to an intensive care unit (ICU) differ based on the academic status of the institution and the total operative volume of the unit. Methods: This was a retrospective analysis using the eICU Collaborative Research Database v2.0, a national database from participating ICUs in the United States. All patients admitted directly to the ICU from the operating room were included. Transfer patients and patients readmitted to the ICU were excluded. Patients were stratified based on admission to an ICU in an academic medical center (AMC) versus non-AMC, and to ICUs with different operative volume experience, after stratification in quartiles (high, medium-high, medium-low, and low volume). Primary outcomes were ICU and hospital mortality. Secondary outcomes included the need for continuous renal replacement therapy (CRRT) during ICU stay, ICU length of stay (LOS), and 30-day ventilator free days. Results: Our analysis included 22,180 unique patients; the majority of which (15,085[68%]) were admitted to ICUs in non-AMCs. Cardiac and vascular procedures were the most common types of procedures performed. Patients admitted to AMCs were more likely to be younger and less likely to be Hispanic or Asian. Multivariable logistic regression indicated no meaningful association between academic status and ICU mortality, hospital mortality, initiation of CRRT, duration of ICU LOS, or 30-day ventilator-free-days. Contrarily, medium-high operative volume units had higher ICU mortality (OR = 1.45, 95%CI = 1.10-1.91, p-value = 0.040), higher hospital mortality (OR = 1.33, 95%CI = 1.07-1.66, p-value = 0.033), longer ICU LOS (Coefficient = 0.23, 95%CI = 0.07-0.39, p-value = 0.038), and fewer 30-day ventilator-free-days (Coefficient = -0.30, 95%CI = -0.48 – −0.13, p-value = 0.015) compared to their high operative volume counterparts. Conclusions: This study found that a volume-outcome association in the management of postoperative patients requiring ICU level of care immediately after a surgical procedure may exist. The academic status of the institution did not affect the outcomes of these patients.
Proximity to Alcohol Sellers and Dose Response Relationship Between Alcohol Consumption With Intimate Partner Violence in Rural Southwestern Uganda
Authors: Ohurira Tushaba , Iyer Hari S. , Wagman Jennifer A. , Hahn Judith A. , Bajunirwe Francis
Published: April 2022

Introduction: Intimate partner violence (IPV) is associated with several adverse public health outcomes and alcohol use is one of its risk factors. Proximity to alcohol selling points could be linked with problem drinking and IPV. We aimed to determine whether proximal location to alcohol and intensity of alcohol consumption are associated with IPV in rural southwest Uganda.

Methods: We conducted a cross-sectional study in rural southwest Uganda with structured interviews at household level. We used the alcohol use disorders identification test (AUDIT) and the Conflict Tactics Scale to measure past year alcohol consumption and IPV (perpetration and victimization). We estimated Euclidean distances between participants’ households and nearest alcohol outlets using geographic information systems. We used generalized estimating equation models to calculate adjusted odds ratios (aOR) for the factors associated with IPV.

Results: We enrolled 742 participants and median age was 41 years (inter-quartile range or IQR 32-53) and 52.2% of respondents were male. The overall prevalence of IPV in the past year was 52.2%. In a multivariable regression model, women (aOR = 2.24, 95%CI 1.28, 3.91) compared to men, those living proximal to an alcohol selling point (OR = 1.77, 95% CI 1.38, 2.27) were more likely to experience IPV. There was a dose-response relationship between alcohol consumption and IPV. With non-drinkers as the reference category, the aORs were 4.54 (95% CI 2.04, 10.08) for casual drinkers, 10.53 (95% CI 4.15, 26.77) for hazardous drinkers and 15.31 (95% CI 4.73, 49.54) for alcohol dependent drinkers.

Conclusion: IPV is very common and has a dose-response relationship with alcohol consumption and drinking outlet proximity. There is an urgent need for IPV and alcohol interventions programs in these rural communities. Policy to restrict proximity of alcohol outlets to residential locations should be examined as an intervention for alcohol consumption and IPV perpetration.
Towards Career Satisfaction by Career Adaptation Model Among Individuals With Visual Impairment
Authors: Salimi Samaneh , Nilforooshan Parisa , Sadeghi Ahmad
Published: April 2022

The present study aimed to examine the fit of the career adaptation model for individuals with visual impairment. This study was conducted on 319 individuals with visual impairment. The results demonstrated the relationship between adaptivity and adaption was fully mediated by adaptability and adapting. In addition, career adaptability partially mediated the relationship between adaptivity and adapting. However, the results did not confirm the mediating role of adapting in the relationship between adaptability and adaptation. Finally, the results indicated the full mediator role of adaptability in the association between adaptivity and adaptation. The findings highlighted the important role of adaptability in the career adaptation model to explain career satisfaction. Therefore, intervention programs based on career adaptability can empower individuals with visual impairment and promote career satisfaction.
A Real World Perspective of PARP Inhibitor Use in Gynecological Cancer Patients
Authors: Lee Chung-Shien , Hernandez Jennifer , Liang Connie , Leung Ashley , Stefanov Dimitre G. , Cheng Kit , John Veena
Published: April 2022

Introduction: Over the last few years, targeted therapy has become the mainstay maintenance treatment of patients with ovarian cancer including patients with BRCA1/BRCA2 mutations. Poly ADP ribose polymerase inhibitors (PARPi) are effective in the treatment of patients who are in complete or partial remission. PARPi are known to cause hematological adverse events (AEs), but have not been compared directly to each other. Objective: Primary objective was to compare the incidence of hematological and non-hematological AEs associated with the use of PARPi. Methods: This was a single institution, retrospective study evaluating patients who were treated with PARPi for ovarian cancer from January 2017 to October 2020. Patients were stratified according to which PARP inhibitor they received. Results: Ninety-two patients were included in final analysis. Thirty-one (33.7%) patients received niraparib and 61 (66.3%) patients received olaparib. Median age of patients were 64.3 (range, 33.8 to 92.3) years, 66 (71.7%) were white, and 84 (91.3%) had an ECOG PS of 0/1. Patients in the niraparib group experienced a higher rate of hematologic AEs, with 11 (35.5%), 20 (64.5%), and 18 (58.1%) experiencing neutropenia, anemia, and thrombocytopenia, respectively. Eight (13.1%), 24 (39.3%), and 16 (26.2%) patients in the olaparib group experienced neutropenia, anemia, and thrombocytopenia, respectively. Conclusion: This single institution retrospective study outlines the hematological toxicities observed between two PARPi. Our results suggested that niraparib tended to be associated with a higher risk for hematologic toxicities than olaparib. Anemia was the most common hematologic toxicity which was consistent with what has been widely documented in the literature.
The Impact of Traumatic Events on Mental Health Among Older African American and Black Caribbean Adults
Authors: Brooks Jasmin R. , Taylor Robert Joseph , Chatters Linda M.
Published: April 2022

Objectives: This study examined the frequency and impact of traumatic events on the mental health of older African American and Black Caribbean adults. Methods: The current study used data from the National Survey of American Life of 1,135 African American and 426 Black Caribbean adults aged 50 and older. Analysis examined the impact of traumatic events on both positive (i.e., happiness and life satisfaction) and negative (i.e., depressive symptoms, psychological distress, and 12-month anti-depressant use) domains of mental health. Results: Findings indicate that approximately 80% of older African Americans and Black Caribbeans reported experiencing a traumatic event at some point in their lifetime. Among African Americans assaultive violence was associated with more depressive symptoms, lower levels of life satisfaction, and lower levels of happiness. This was not the case among Black Caribbeans. Conclusions: These findings provide preliminary insight in mental health outcomes for older African American and Black Caribbean adults.
Change in charge carrier dynamics by incorporating ionic liquid into poly ethylene oxide–based sodium acetate polymer electrolytes
Authors: Gupta Sandhya , Singh Pramod K , Bhattacharya B
Published: April 2022

Poly (ethylene oxide) based sodium ion conducting solid polymer electrolytes films (salt NaCH3COO) with varying amounts of an ionic liquid, 1-ethyl 3-methylimidazolium thiocyante were prepared by solution-cast method. All the prepared samples were characterized in detail for their ion transport characteristics at room temperature and temperature dependent behavior as well using electrochemical impedance spectroscopy. The measurement of ionic conductivity shows the many fold enhancement due the incorporation of ionic liquid in the polymer electrolyte matrix. The charge carrier density and mobility of charge carriers has been calculated and used for explaining the conductivity variations in these films. The increase in conductivity has been explained in terms of plasticization effect of ionic liquid and number of charge carriers per unit volume of electrolyte.
Performance investigation of heat exchanger tube fitted with hyperbolic-cut twisted tape in turbulent flow
Authors: Rajan Abhijit , Prasad Laljee
Published: April 2022

Investigation of Nusselt number, friction factor, and thermo-hydraulic performance characteristics in turbulent flow tube with hyperbolic-cut twisted tape (HCTT) has been reported using ANSYS Fluent 19.2. The effect of hyperbolic-cut ratios (0.3 [Formula: see text] b/c [Formula: see text] 1.2) and non-dimensional cut width (0.56 [Formula: see text] c/w [Formula: see text] 0.89) are inspected for 10000 [Formula: see text] Re [Formula: see text] 22000 in a tube of 20 mm diameter. In the present study, the comparison is made among all available turbulence models, and k- [Formula: see text] RNG turbulence model is found to be reliable. The present turbulence model is also compared with existing experimental data. The tube equipped with HCTT provides swirling of flow and additional flow around the cuts. This induced flow enables heat transfer and pressure drop between the core and near-wall region of the tube. The presence of hyperbolic-cut leads to better mixing and centrifugal motion of near-wall fluid, which has a remarkable effect on heat transfer and friction factor characteristics in the fluid region. The Nusselt number, friction factor, and thermo-hydraulic performance of HCTT are enhanced up to 12.16%, 22.54%, and 7.36% compared to TT, respectively. The performance of the present geometry is compared with twisted tape and is found to be best for non-dimensional cut width of 0.67 for all the values of Re 10000–22000. The performance of the proposed geometry has also been compared with existing works, and performance is found to be excellent for Re [Formula: see text] 16000. Further, correlations have been developed to predict the Nusselt number, friction factor, and thermo-hydraulic performance. This numerical investigation could be expected to be helpful for engineers and researchers in designing modern heat exchangers.
Structure improved design and intensity experiment on drive coil
Authors: Xiaocun Guan , Guan Shaohua , Lida Yuan , Biao Wu
Published: April 2022

To sustain the strength of electromagnetic force, according to the stress distribution of a drive coil, the prime design requirements of the drive coil are presented, the drive coil is designed and manufactured, and intensity damage experiments are carried out. The experiments indicate that the heat and joint effect of electromagnetic forces is the major cause of drive coil damage, and interturn insulation damage is the main damage mode. Based on this foundation, two methods are presented to reinforce the density of the drive coil; in the first method, the material of the reinforced structure of the drive coil shifts from nylon to steel; in the second method, the drive coil cooling system and temperature control systems are presented. The relationship between flow velocity in the cooling system and temperature rise is determined based on the flow-solid coupled theory, and temperature distribution of the drive coil is analyzed in different flow velocities. The experimental testing of the drive coil cooling system is made. Finally, the design manufacturing of the drive coil and epoxy filling is described in detail, which is the engineering foundation for the coil launcher.
A novel nature inspired 3D open lattice structure for specific energy absorption
Authors: Ashok Dara , Raju Bahubalendruni M. V. A. , Johnney Mertens A. , Balamurali Gunji
Published: April 2022

Energy absorption is a key performance criterion for several engineering structures. Lightweight lattice structures are better suited for this purpose. The convolute design patterns that exist in nature are proven effective for several engineering applications. In this paper, a George lily flower leaf is considered to build a novel 3D open lattice pattern for specific energy absorption (SEA) purposes. A multi-cellular specimen is designed and fabricated using Vat photopolymerization 3D printing process. Quasi-static compression tests have been conducted and the performance of proposed structure is compared with 2.5D closed thin-walled structures and found the proposed 3D open lattice structure has shown significant improvement in SEA over other thin-walled structures.
Magnetorheological finishing of aluminium cylindrical roller for enhanced performance of printing operation
Authors: Singh Manpreet , Paswan Sunil Kumar
Published: April 2022

Aluminium is the most versatile engineering material for various industries, such as transport, machinery, metallurgy and printing. The aluminium cylindrical roller plays a significant role in the printing machine. In order to evenly distribute the pressure and for accurate tolerances roller needs to be perfect and uniformly finished. Owing to their ductility and lesser hardness, it is difficult to achieve uniform and fine finishing by conventional finishing methods. The rotary magnetorheological (MR) method is established to satisfy this requirement. The MR polishing fluid composition is initially analysed in order to obtain a fine finish. The central composite design was employed to optimize the finishing parameters. The batch gradient descent algorithm is used to validate the RSM optimization of process parameters. Batch gradient descent gives the mathematical model which validates the RSM mathematical model. The scan electron microscopy, reflectivity test and surface roughness profile check were carried out to track the surface texture and the cylindrical aluminium roller's ruggedness. The standard deviation test is performed to measure the uniformity of the finished surface and demonstrate that the uniformity of the finished surface which is increased. Geometric measurements are tested by the way of the surface waviness measurement. The results of earlier process parameters and with addition of reciprocation of work-part is compared and experimentation performed on 120 mm long and 25 mm diameter of the aluminium cylindrical roller with 30 mm length for each trial.
Enhanced mixing in dual-mode cylindrical magneto-hydrodynamic (MHD) micromixer
Authors: Buglie W. L. N. , Tamrin K. F.
Published: April 2022

The proposed cylindrical magneto-hydrodynamic (MHD) micromixer developed in this study was a geometrically modified conventional T-micromixer combining the characteristics of passive and active micromixers. Characterization was achieved by observing the mixing efficiencies of NaCl solution (1% concentration) based on supplied electrical potential and inlet flow rates. The design mainly aimed to utilize the pumping capability of the magneto-hydrodynamic principle as a secondary element to give counter pumping energy towards inlet flows, such that perturbation of fluid increased mixing performance. NaCl solution was mixed by advection through the stretching and folding by micro-vortices generated in the mixing reservoir. The cylindrical MHD micromixer achieved its highest mixing index of 99.42% at Re = 40 with 3 V of direct-current potential (VDC) supplied to the electrodes. Mixing efficiency increased in a considerably similar and linear pattern for Re = 5, 10, 20, and 40 within the electrical potential range of 0.5 ≤ V ≤ 3.0. Control was gained by manipulating the external electrical potential source which only required a smaller capacity of direct-current voltage sources. Overall, the proposed cylindrical MHD micromixer, which emphasizes the use of inexpensive material and simple design, has been experimentally proven to be practical as compared to the passive and active micromixers found in the literature.
A review study on the performance enhancement of solar parabolic trough receiver by various passive techniques
Authors: Singh Sushma , Samir Sushant , Kumar Khushmeet
Published: April 2022

This is a new era where the world’s energy consumption is so high and is likely to increase over 60% of current consumption by the year 2030. Therefore, renewable energy should be used most frequently. The most preferred alternative to fossil fuels is solar energy but converting solar energy into usable form is the most challenging part. The conversion to thermal energy is the one option. In the area of solar thermal power generation, a solar parabolic trough (SPT) collector is an effective method. Also, the use of passive methods to enhance the thermal performance of these parabolic trough receivers is currently the researcher’s interest This review study is focused on different types of geometrical modification (Artificial roughness) used to enhance the thermal performance of SPT receivers. Based on the extensive study it has been found that conical strip insert is a very broad field for research as it can enhance the thermal performance up to 5–10 times. Also there are parameters associated with the conical strips like shape, pitch, angle of twist, slant angle, geometry angle, etc. which can contribute to better performance when used in SPT receiver.
Experimental and simulation approach of surface generation on K-80 alumina ceramic by recently developed sustainable FB-HAJM using novel nozzle design
Authors: Pradhan Subhadip , Dhupal Debabrata
Published: April 2022

K-80 alumina ceramic makes it challenging to machine them economically due to extreme hardness. Fluidized bed-hot abrasive jet machining (FB-HAJMing), in which a target profile is eroded by the impingement action of air-hot abrasive jet, which containing fine hot abrasive grains for machining of K-80 alumina ceramic materials without thermal damage. This study is intended to analyse kerf angle (KA), surface roughness (Rz) and material removal rate (MRR) using HAJMing process of K-80 alumina ceramic. Fifteen sets of experimental trials were conducted two times using tungsten carbide (WC) nozzle with and without internal thread. The identified three cutting parameters i.e., air pressure (P), abrasive temperature (T) and stand-off-distance (SOD), were considered for experimental design. Furthermore, the response surface methodology (RSM), statistical techniques (here, desirability function approach) followed by computational approach (here, genetic algorithm) are respectively employed for experimental investigation, predictive modelling and multi-objective optimization. Subsequently, confirmation tests evaluate the efficiency of the suggested two multi---objective optimization methods to rationalize the utility and awareness of the usefulness of hot abrasives in HAJMing. Moreover, computational fluid dynamics (CFD) modelling was utilized to develop a comprehensive relation between HAJMed profile geometry and erosive flow. Finally, the environmental ‘Pugh Matrix’ approach is proposed for the HAJMing process sustainability evaluation. The results indicated a desire to improve the cutting efficiency for material erosion by using hot abrasives in the HAJMing procedure. The most important parameter for surface roughness is abrasive temperature, while pressure is important for both KA and MRR. The use of hot abrasives in the FB-HAJM process has demonstrated a focus on improving the cutting performance for material removal. From an economic standpoint, the current study presents a technological criterion for feasible industrial applications of the FB-HAJM method, such as in aerospace, precision manufacturing, and biomedical field.
Effect of heat treatments on the microstructure and wear behaviour of a selective laser melted maraging steel
Authors: Özer Gökhan , Khan Hamaid Mahmood , Tarakçi Gürkan , Yilmaz Mustafa Safa , Yaman Paşa , Karabeyoğlu Sencer Süreyya , Kisasöz Alptekin
Published: April 2022

This study applied classical and intercritical heat treatments to maraging steel (MS1) samples produced with standard additive manufacturing (AM) production parameters. The effects of heat treatment parameters on the microstructure-phase changes of the material were investigated by optical microscope (OM), scanning electron microscope (SEM), Electron Dispersion Spectroscopy (EDX), and X-ray diffraction analysis (XRD) techniques. Likewise, microhardness and dry sliding wear tests were performed to determine the relationship of heat treatment parameters (especially intercritical heat treatment) to the mechanical properties and wear of the material. The results reveal that the intercritical heat treatment is exciting for the AM/MS1 material.
Detection of rail local defects using in-service trains
Authors: Shadfar Morad , Molatefi Habibollah
Published: April 2022

As track components deteriorate, their interaction dynamic response will alter accelerations on the train. Measuring acceleration on train components is a method to conduct condition monitoring of track defects. The measured signal can be used for the detection of rail surface defects which implement impacts on measured accelerations. In this paper, the axle-box acceleration (ABA) is measured in a subway as a case study. Fourier transform (FFT), empirical mode decomposition (EMD) and ensemble EMD (EEMD) methods are used to study accelerations relative to the track. Wheel frequencies are calculated using finite element method (FEM) to determine frequency couplings. Velocity-dependent/independent components and source of excitation of the measured signal are distinguished. Results indicated that the FFT approach can be applied for both velocity-dependent and velocity-independent vibration components for frequencies up to 680 Hz. Also, the EEMD method can be used to distinguish the impact component of the measured signal.
Quantitative fatigue evaluation of complex welded connections and application in a train traction motor frame component
Authors: Bingzhi Chen , Zhengping He , Dong Pingsha , Song Shaopin , Wenzhong Zhao
Published: April 2022

Welded connections are common in rail vehicle structures and associated equipment. It is well known that fatigue behaviors of welded structure are controlled by fatigue capability of welded joints. Although there exists numerous joint design guidance in Codes and Standards as well as best practices, they are largely empirical and difficult to apply in fatigue assessment of complex joints. In this paper, we adopt a mesh-insensitive structural stress method recently stipulated by ASME Code for fatigue evaluation of pressure vessels and piping components. Starting with stress concentration evaluation of two typical, but complex welded connections of relevance to some rail vehicle structures, we examine how the joint design principle inferred from the two examples can be effectively applied to an actual traction motor frame design and its effective fatigue improvement method. The experimental validation process is also presented for the proposed fatigue improvement technique.
Theoretical model of fatigue limit of full-size axle with different impact defects
Authors: Zhou Suxia , Duan Suyu , Wu Yi , Sun Yuduo , Zhao Zhang
Published: April 2022

The impact defects on the surface of the axles of high-speed trains may cause hidden dangers to the safe operation of the trains. In order to study the influence of different shape defects on axle fatigue limit, the method of combining finite element simulation and fatigue test is adopted. According to the statistics of the foreign object damage impact defect of the axle in the workshop, impact defects were prefabricated on the axle specimen surface, stress analysis of the impact defect area was carried out, and then the more dangerous defect shape was obtained. Fatigue tests were carried out on prefabricated axle specimens. The P-S-N curves of each specimen group were fitted by the approximate Owen one-side tolerance limit method. In line with the fatigue test results of samples, considering the factors such as axle surface mass coefficient, size effect coefficient and load type, to ensure the security of the train operation, fatigue strength safety factor Sσ is introduced to establish a full-size axle fatigue prediction mathematical model. The fatigue limit of full-size axle with impact defects was predicted and the accuracy of the model was proved. Finally, on the basis of the defect shape, the modified EI Haddad model was used to fit the two-parameter theoretical model of defect depth and full-size axle fatigue limit, the standards were combined for safety assessment.
Data-driven fault-tolerant control for unmanned aerial vehicles without using identification model
Authors: Zheng Duo , Xu Xinghua , Lin Defu
Published: April 2022

Unmanned aerial vehicle (UAV)’s fault-control problem was studied in this paper, and data-driven fault-tolerant control scheme was developed for acceleration tracking control of UAV in order to cope with the uncertainties induced by aerodynamic damage. A linear UAV dynamic model was given with reasonable assumptions, and the acceleration tracking control for UAV was converted to solving an infinite-horizon optimal control problem. The augmented algebraic Riccati equation (ARE) is derived, and its solution stability is proved based on Lyapunov theory. The data-driven control algorithm is further derived for online solving of the augmented ARE with only using flight data. The proposed algorithm is based on experience replay of flight data rather than model knowledge, so it greatly reduces the effect of uncertainties induced by aerodynamic damage on the flight control system for UAVs. Finally, the effectiveness of developed algorithm is verified through the numerical simulations under different uncertainties induced by aerodynamic damage.
Understanding Everyday Events: Predictive-Looking Errors Drive Memory Updating
Authors: Wahlheim Christopher N. , Eisenberg Michelle L. , Stawarczyk David , Zacks Jeffrey M.
Published: April 2022

Memory-guided predictions can improve event comprehension by guiding attention and the eyes to the location where an actor is about to perform an action. But when events change, viewers may experience predictive-looking errors and need to update their memories. In two experiments ( Ns = 38 and 98), we examined the consequences of mnemonic predictive-looking errors for comprehending and remembering event changes. University students watched movies of everyday activities with actions that were repeated exactly and actions that were repeated with changed features—for example, an actor reached for a paper towel on one occasion and a dish towel on the next. Memory guidance led to predictive-looking errors that were associated with better memory for subsequently changed event features. These results indicate that retrieving recent event features can guide predictions during unfolding events and that error signals derived from mismatches between mnemonic predictions and actual events contribute to new learning.