bluuebunny/crossref_metadata_2025 huggingface dataset:
Static behavior of thick flax/epoxy composite laminates: multi-instrumentation mechanical failure analysis
Authors: Batouche Fatiha , Ameur Mohamed F , Zitoune Redouane , Morel Claire , Toubal Lotfi
Published: November 2024

The use of thick composites in civil engineering and aeronautics fields is becoming increasingly common in primary or secondary structures, and natural fiber composites present a valuable alternative in terms of mechanical performance, cost and environmental impact. Investigating the mechanical characteristics and damage mechanisms that occur in thick flax/epoxy laminates is the primary objective of this research. Firstly, multi-instrumented bending tests and interlaminar shear tests were carried-out to assess the mechanical properties and failure characteristics of the composite. This multi-instrumentation concerns, the Acoustic Emission and the Digital Image Correlation techniques. In addition, postmortem observations utilizing Computed Tomography (CT) Scan and scanning electron microscopy (SEM) were carried out. Finite Elements and analytical models were proposed to evaluate the mechanical response. At the macroscale, results demonstrate a good correlation in the elastic zone between the numerical, analytical and the experimental. However, at the mesoscale the correlation is less evident especially close to the final failure of the laminate. Based on SEM and X-ray tomography images, the differences recorded are related mainly to the plies thickness variations and the waviness phenomenon induced by the manufacturing process.
Standing Their Ground While Seated: Narratives of Widowhood Activism Against the Ritual of Widow Dispossession in South Africa
Authors: Ndlovu Thatshisiwe
Published: November 2024

Widows in Africa are mostly perceived as helpless victims of harmful widowhood practices. The article offers new insights into the understanding of widowhood and the status of widows in the context of these practices. Integrating feminist research and narrative theory, the paper examines widows’ responses to the ritual of the ‘sitting and its associated practice of widow dispossession. I examine how widows challenge the customary ritual of ‘sitting’ from a place where enforced silences and widow dispossession are ritualized to where widowhood activism is born. The article draws from a feminist theory of activism, highlighting that widows counter silencing and dispossession through speaking out, speaking through objects, delegating someone to act on their behalf, disobedience and non-cooperation. In summary, the article concludes that the practice of ‘sitting’ is a politically charged space that is both a site of widow dispossession and resistance.
How Proactive Personality Impact Career Adaptability? The Mediating Role of Strengths Use and Job Crafting
Authors: Li Hui , Sun Lijun , Song Suhao , Jin Hui
Published: November 2024

Studies have demonstrated that proactive personality and career adaptability are correlated. Less is known, however, about how proactive personality impact career adaptability. Based on the conservation of resources (COR) theory, the present study aimed to investigate the association between proactive personality and career adaptability, and explored the mediating effects of strengths use and job crafting. Three-wave questionnaires data was conducted with 374 employees from diverse organizations to test the hypotheses of this study. The results of our study showed that proactive personality was positively related to career adaptability. Moreover, strengths use and job crafting separately played a mediation role in the link between proactive personality and career adaptability. Additionally, a sequential mediation effect was observed, with proactive personality influencing career adaptability through the sequential mediators of strengths use and job crafting. This study offers valuable insights into the specific pathway from proactive personality to career adaptability.
Brexit biographies: Everyday articulations of race, class and nation through the keyhole issues of Empire and ‘culture wars’
Authors: Tyler Katharine , Blamire Joshua
Published: November 2024

Some media and political science narratives suggest post-Brexit Britain is locked in a culture war epitomised by the differences thought to divide Leavers and Remainers in terms of their national values, classed and racialised identities. This article sets out to provide a more complex depiction of reality. To do this, we draw on in-depth interviews with individuals across Leave, Remain, national, migrant, racial, ethnic and class identities to trace how they articulate ideas of Empire and nationhood when they discuss Brexit and the legitimacy of statues linked to British histories of colonialism and enslavement. We explore the contrasts and complexities in the ways in which individuals supporting Leave or Remain mobilise what we call their ‘Brexit biographies’ when they think about questions of Brexit, Empire and nationhood. On the one hand, our Remain interlocutors articulate more politically progressive racialised and classed articulations of Brexit, Empire and nationhood compared to some Leave supporters. However, on the other hand, when we switch context to examine the legitimacy of statues commemorating histories of colonialism and enslavement with some of the same individuals this distinction in the values of Leave and Remain supporters begins to break down. Our contention is that detailed sociological attention to the connections uniting Leavers’ and Remainers’ reflexive worldviews is required to properly comprehend how individuals experience, as well as reproduce and dislodge, racial, class and national inequalities that underpin the fabric of British society.
Continuing personhood and the increasing bureaucratisation of death: ‘My dad doesn’t need electricity in heaven’
Authors: Reed Kate , Balazs Anna
Published: November 2024

Bureaucracy has been a core sociological concern since the discipline’s inception. While sociologists have explored the impact of bureaucracy on many areas of social life (from work to immigration policy), less is known about how bereaved individuals navigate the bureaucracy of death. After a loved one dies a range of time-consuming and time-sensitive hidden bureaucratic tasks must be completed – such as notifying officials and managing the estate – across public, private and third sector organisations. How do individuals experience and navigate such bureaucracy at a time of extreme sadness and vulnerability? Drawing on data from a qualitative study on death administration, this article explores people’s encounters with bureaucratic processes after bereavement. The article illuminates the challenging nature and ultimate failure of bureaucratic procedures in death administration. Such procedures create insensitivity around issues of personhood, often compounding emotional distress and vulnerability. Our analysis illuminates the ways in which this can lead to the operation of bureaucratic violence, a specific type of domination in which citizen subjectivities are affected by abstract rules and hostile organisational structures. By shedding light on death administration processes the article extends sociological understandings of bureaucracy and offers an innovative contribution to literature on grief.
The Effect of Digital Supervision of China Basic Medical Insurance on Out-of-pocket Expenditure: Evidence from Quasi-natural Experiment
Authors: Wang Chuncheng , Song Chen , Wu Jing , Ning Yanpeng , Wang Shuai
Published: November 2024

Scientific research has shown that the sustainability of public health insurance is crucial for governments to effectively manage the risks associated with populations aging. In response, the Chinese government has initiated efforts to ensure the long-term viability of its medical insurance funds. This study utilizes data from 24 484 respondents in the 2013, 2015, 2018, and 2020 waves of the China Health and Retirement Longitudinal Study (CHARLS), treating the digital supervision of medical insurance funds as a quasi-natural experiment. The study employs a difference-in-differences (DID) model to evaluate the policy effects and uses heterogeneity analysis to explore variations in impact. The objective is to assess the effectiveness of digital supervision and understand how it achieves its policy goals. The findings indicate that digital supervision of medical insurance funds has a significant positive impact on residents’ out-of-pocket medical expenditure. Heterogeneity analysis reveals that the policy’s effect is particularly strong in urban samples, especially among younger and elderly urban residents, while showing no significant impact on rural populations. This suggests that the policy has a greater influence on groups with higher moral hazard. By implementing digital supervision of medical insurance funds, the Chinese government has ensured the sustainability of these funds, laying a foundation for mitigating the risks associated with population aging. Additionally, the policy has contributed to promoting healthcare equity and reducing the waste of medical resources.
Perceptions of primary mental health care in a semi-rural setting in the Eastern Cape of South Africa: a qualitative inquiry
Authors: Booysen Duane D , Haine Phillipa
Published: November 2024

Despite extensive global efforts to prioritise and improve primary mental health care, challenges and opportunities within resource-constrained settings, particularly in low- and middle-income countries (LMICs) such as South Africa, persist. The study explored the barriers and opportunities in primary mental health care in a resourced-constrained setting in the Eastern Cape, South Africa. Moreover, and based on the rationale, the study explored how staff and patients within a low-resource community experience and perceive mental health care at a primary health level. Using a qualitative method, semi-structured interviews were conducted with 24 participants (patients = 11, staff = 13), recruited using purposive sampling. Thematic analysis of the data revealed three overarching themes: (1) Challenges and opportunities, (2) Medication and admission, and (3) Mental health is misunderstood. The findings suggest that patient experiences of mental health care in primary health clinics are complex, approaches to mental health care are predominantly pharmacological and that mental health stigma persists. The findings indicate the need for integrative approaches to mental health care and improved mental health literacy in communities. They also align with the key action areas outlined in the National Mental Health Policy Framework and Strategic Plan (2023-2030). However, decisive governmental investment, implementation, and leadership are necessary. Future research, through systems approaches and implementation science, should focus on enhancing primary health clinic experiences, expanding mental health care provision through various community-based implementation strategies, such as task-sharing, low-intensity psychological interventions, and implementing mental health literacy initiatives to mitigate the impact of mental health stigma.
An Examination of Prison-Based Programming and Prison Misconduct
Authors: Reale Kylie S. , Usman Hina , Rodriquez Nancy
Published: November 2024

Prison misconduct can produce a range of detrimental consequences across prison systems. Research indicates that both individual- and prison-level characteristics predict misconduct; however, there is increasing evidence that this relationship can be mediated by program participation. Accordingly, this study seeks to expand knowledge on the relationship between prison misconduct and prison programming by examining two types of prison programs (a) Thinking for a Change and (b) Functional Literacy. Specifically, we examine the impact of these programs across different forms of misconduct (i.e., drug, violence between incarcerated people, assault on staff, and other non-violence) using propensity score matching on sample of 3,795 incarcerated individuals. Findings showed participation in the Functional Literacy program was associated with reductions in drug misconduct and participation in the Thinking for a Change Program was associated with reductions in staff assault and drug misconduct. Implications for correctional practice and policy are discussed.
Mechanical and tribological characteristics of glass fiber and rice stubble-filled epoxy-LD sludge hybrid composites
Authors: Purohit Abhilash , Pradhan Priyabrat , Palanimuthu Suresh , Kumar Arvind , Chauhan Pankaj Kumar
Published: November 2024

In this work, bidirectional rice stubble fiber (RS), Glass fiber (GF), and Linz-Donawitz sludge (LDS) are used as reinforcement for the fabrication of epoxy (EP) based hybrid composite materials. The mechanical (tensile, flexural, compressive strength), and physical (density, void content) characteristics were evaluated as per ASTM standards. The tensile, compressive and flexural strength values of neat epoxy increased from 45 to 111 MPa, 22.5 to 58 MPa and 84 to 140 MPa respectively, with the addition of 6 % RS in EP-LDS-GF-RS composites. With the continuous addition of RS content, the density of the EP-LDS-GF composite gradually decreases, while void content increases gradually within 0.1 %, but both are higher than pure resin. Dry sliding wear tests are carried out on the composites to acquire the specific rate of wear (SWrate). Taguchi’s design of experiment analysis is used to highlight the effect of various dependent parameters on SWrate. Artificial Neural Network (ANN) tool is used to predict the combined effect of different input parameters on the SWrate. From the SEM analysis, it is observed that material removal is significantly less near the region of filler content and hence the RS content is found to be the predominant control factor affecting the wear rate of the composites.
Diagnostics and prognostics system design integrating hybrid Siamese and model-driven learning
Authors: Abbasi Muhammad Asim , Huang Shiping , Khan Aadil Sarwar
Published: November 2024

The article introduces a hybrid fault detection and prognosis system design for motor bearings, which is crucial for the reliability and efficiency of rotating machinery. The focus is on the concern of bearing fault detection with limited data quantity. Traditional approaches struggle with fault detection depending on the quantity and quality of historical data samples, especially in dynamic conditions, often failing to capture long-term dependencies and uncertainties in bearing health states, thereby limiting precise fault detection and remaining useful life predictions. To overcome these challenges, the research proposes a novel hybrid framework that combines data-driven and model-driven learning. This framework employs the Siamese neural network (SNN) containing two identical subnetwork models for fault detection and Bayesian estimation for prognosis purposes, bridging the gap between data-driven and model-based approaches. SNNs excel in learning from limited labeled data and are suitable for real-time fault detection. Experimental validation with the PRONOSTIA-FEMTO bearings dataset confirms the framework’s superior performance in fault detection, promising improved maintenance practices and equipment reliability in industrial processes.
Gesture and speech in variation sets directed to Spanish-learning toddlers in adult–child interactions
Authors: Alam Florencia , Casla Marta , Ibañez María Ileana , Rosemberg Celia Renata
Published: November 2024

The study adopts a multimodal perspective, looking at adults’ use of gestures in variation sets (VS; i.e. sequences of partial self-repetitions occurring in successive utterances of varying form) addressed to Spanish-learning toddlers in adult–child interactions. We seek to address the following question: Do adults make simultaneous use of VS and gestures to amplify their effect while interacting with toddlers? We consider the proportion of bimodal utterances, the types of gestures, the pragmatic function of the utterances, and the ongoing activity. Thirty 18-month-old children (17 Argentinian and 13 Spanish) and their principal caregivers were video recorded for 15 minutes in spontaneous reading and playing situations. Transcriptions and annotations were done with ELAN. Results showed that verbal utterances were more frequent than bimodal utterances in VS. Gestures were mostly used in VS with a regulatory function. Pointing was the type of gesture most frequently used, and its proportion increased in VS. Gestures were employed more frequently in book-sharing activities. Findings revealed that although VS are a bimodal (gesture and speech) phenomenon they are predominantly verbal and that regulatory pragmatic function explains adults’ use of gesture.
Pterygopalatine Catecholamine-Secreting Paraganglioma: A Diagnostic and Therapeutic Challenge
Authors: Azar Adel , Alkheder Ahmad , Sukkar Ghina , Dmirieh Ahmad , Alassaf Arige
Published: November 2024

Paragangliomas are rare neuroendocrine tumors originating from the paraganglia. They are mostly benign, slow-growing, and non-secretory. This report describes a rare case of a catecholamine-secreting paraganglioma located in the pterygopalatine fossa. A 45-year-old man presented with severe hypertension, occipital headache, and facial pain. Imaging revealed a large pterygopalatine mass, initially misdiagnosed as chondrosarcoma. Gamma knife stereotactic radiosurgery was performed, followed by surgical resection via a maxillary swing approach. Histological examination confirmed the zellballen pattern typical of paraganglioma. Post-surgery, the patient’s blood pressure normalized immediately and subsequently. This case highlights the diagnostic challenges of head and neck paragangliomas in atypical locations and underscores the importance of surgical intervention for catecholamine-secreting tumors. Future studies should focus on refining diagnostic protocols and comparing the efficacy of radiosurgery versus surgical resection for these tumors.
Virtual Control Groups in Non-clinical Toxicity Studies: Impacts on Toxicologic Clinical Pathology Data Interpretation
Authors: Adedeji Adeyemi O. , Naor Adi Wasserkrug
Published: November 2024

One of the emerging concepts on the reduction of animal use in non-clinical studies is the use of virtual control group (VCG) to replace concurrent control group (CCG). The VCG involves the generation of a control data from historical control data to match a specific study design. This review focuses on two recently published proof-of-concept (POC) studies conducted in rats. One major issue that was consistently seen across these POC studies was the non-reproducibility of some quantitative endpoints between the CCG and the VCG, with clinical pathology parameters being the most affected. The inconsistencies observed with the clinical pathology parameters when using VCGs may lead to: (1) misconception about the accuracy and sensitivity of traditional clinical pathology biomarkers and its implications on safety monitoring in the clinic; (2) inability to correctly identify and characterize organ dysfunctions; (3) interference with the weight-of-evidence approach used in identifying hazards in toxicologic clinical pathology and toxicology studies at large; and (4) wrong interpretations and data reproducibility issues. Other alternatives to reduce animal use in toxicology studies are also discussed including blood microsampling for toxicokinetics, scientifically justified use of recovery animals, and appropriate use and continuous investments in new alternative methods.
Investigating gifted students’ higher-order thinking skills in a differentiated learning environment: A case study
Authors: Foo Soon Yen
Published: November 2024

Gifted learners are usually identified as students who show higher levels of aptitude or competence compared to their peers of the same age. Their advanced abilities often require specially designed educational strategies to meet their intellectual needs. By designing educational strategies that are appropriately challenging and intellectually stimulating, educators can support gifted students in reaching their full potential, ensuring that their talents are well-developed. This study aims to investigate how higher-order thinking skills (HOTs) can be developed in gifted students through their participation in an interdisciplinary project within a differentiated learning environment. The HOTs defined in this study are associated with Bloom’s upper-level taxonomy, which includes analysing, evaluating, and creating. The interdisciplinary project was designed using a “backward design” approach, incorporating three subjects: History, Islam, and Moral Education. The study focused on employing differentiated instruction in terms of both content and process. Based on the desired learning outcomes of the three courses, the “big idea” (theme), namely “Independence Commemoration,” is created to guide the instructor in designing an interdisciplinary project. A case study was adopted in the current study. The study involved 21 students, aged 15 and 16, enrolled in a high school in Northern Malaysia offering the Advanced Smart Education Program. Data was collected from interdisciplinary project discussions in Google Docs and analysed qualitatively using the content analysis method. The depth of students’ thinking levels was evaluated using the revised Bloom’s taxonomy. The findings show that the interdisciplinary project, implemented in a differentiated learning environment, was less effective in promoting students’ HOTs, as most students tended to offer superficial responses. The study discussed the challenges of designing and implementing an interdisciplinary project in a differentiated learning environment. It also outlined the implications for school and classroom practices of such a project. Additionally, the study provided recommendations or solutions to address the problems identified based on the findings.
Unseating Mastery: The University and the Promise of the New
Authors: Hörl Erich , Lalu Premesh
Published: November 2024

The conversation between Erich Hörl and Premesh Lalu draws on their extended conversation on efforts to link discordant temporal and spatial encounters with the idea of the university and how, more importantly, to care for the future of its educational responsibilities. While much of the debate on the university is focused on how it is affected by large-scale geopolitical shifts and the rapid expansion of technological resources, Hörl and Lalu bring into view a language of the university that holds to its promise in the sources of a founding supplement that may yet exhibit the potential for guiding the university through turbulent times ahead. This is a call for a retracing of the emergence of the complex hegemony of the master signifier in university discourse, and the potential to supersede it by way of a re-articulation of the desire for a concept of freedom borne out of the emancipation of the 19th-century institution of slavery.
Endovenous treatment for varicose veins of the lower limbs: Comparative histological evaluation of different techniques
Authors: Palombi Luca , Caggiati Alberto , Bianchi Pier Giovanni , Morelli Monica , Martinelli Fabio , Merenda Elisabetta
Published: November 2024

Background

In recent years, tumescent ablative techniques have been joined by non-tumescent ablative techniques. The aim of the research is to study and compare the effects produced by the different endovascular ablative techniques, from the histological point of view, at the level of the venous wall (endothelium, tunica media and adventitia).

Method

The study involves the use of three ablative endovascular techniques (EVLA, MOCA, CGO) on bench for the treatment of the great saphenous vein. The bench procedure was performed in the same way as described in the instructions for use (IFU) of the technical specifications. Tissue samples were formalin-fixed and paraffin-embedded (FFPE). They were stained with hematoxylin and eosin and, in a case, with anti-ERG antibody (MA5-26,245, Termo Fisher).

Result

No perivascular tissue was present. No hematoma or perforation of the vein wall was observed. Histopathological changes after EVLA indicated that the intima including the endothelium and sub-endothelium was completely necrotized. It was observed that the thermal-energy-induced injury in the intima did not reach deeper than the media. Overview shows that in this case the damage is homogenously spread along the entire perimeter. The most evident change in the sample treated with mechanical-chemical ablation (MOCA) technique was the endothelial damage with loss of endothelial cells. Specifically, with the ERG immunostaining it was possible to observe the presence of numerous nuclei exposed towards the lumen of the vein. In the sample treated with cyanoacrylate (CGO), no significant structural alterations were observed. However, an almost complete collapse of the endoluminal walls and the presence of cyanoacrylate residues were observed.

Conclusion

Different histological patterns characterize the individual treatments. However, all techniques have a common feature: the damage is not transmural and the three different layers of the venous walls are always recognizable.
Small Area Estimation of Poverty in Four West African Countries by Integrating Survey and Geospatial Data
Authors: Edochie Ifeanyi , Newhouse David , Tzavidis Nikos , Schmid Timo , Foster Elizabeth , Hernandez Angela Luna , Ouedraogo Aissatou , Sanoh Aly , Savadogo Aboudrahyme
Published: November 2024

The paper presents methodology to generate experimental small area estimates (SAE) of poverty in four West African countries: Chad, Guinea, Mali, and Niger. Due to the absence of recent census data in the four countries, household level survey data are integrated with grid-level geospatial data, which are used as covariates in model-based estimation. Leveraging geospatial data enables reporting of poverty estimates more frequently at disaggregated administrative levels and makes estimation feasible in areas for which survey data are not available. The paper leverages the availability of a recent census in Burkina Faso for evaluation purposes. Estimates obtained with the same survey instruments and candidate geospatial covariates as the other four countries are compared against estimates obtained using recent census data and an empirical best predictor under a unit level model. For Burkina Faso, estimates obtained using geospatial data are highly correlated with the census-based ones in sampled areas but moderately correlated in non-sampled areas. The results demonstrate that in the absence of recent census data, small area estimation with publicly available geospatial covariates is feasible, can lead to large efficiency improvements compared to direct estimation, and improve the timeliness of small area estimates.
The support of autonomy, motivation, and music practice in university music students: A self-determination theory perspective
Authors: Bonneville-Roussy Arielle , Evans Paul
Published: November 2024

Practice may be the single most important activity that musicians can use to improve their performance. Yet practice requires significant effort and can sometimes feel difficult or unenjoyable. For this reason, substantial motivational resources are required to sustain consistent, high-quality practice over long periods. In this study, we used self-determination theory to study the kinds of motivation that predict practice behavior and the potential influence that teachers might have on their students’ behaviors. A total of 213 university music students in the United Kingdom and Canada completed measures of practice time, practice quality, motivation, and their teacher’s teaching style. Hypothesized relationships between these variables were examined using structural equation modeling. Results supported the process model in which teacher autonomy supported predicted autonomous motivation, which in turn predicted practice time and practice quality. Teacher control predicted controlled motivation, but controlled motivation was not predictive of practice time or practice quality. Indirect effects suggested that motivation fully mediates the link between teaching style and practice behavior. The findings add clarity to research aiming to understand the kinds of social environments that lead students to develop forms of motivation that enable them to practice in a way that is enjoyable and productive.
Studies on Piezoelectric vibrations in thermoelastic microbeam resonator with memory and nonlocal effects
Authors: Mondal Sudip , Sur Abhik
Published: November 2024

The present article analyzes the thermoelastic vibration for a transversely isotropic piezothermoelastic (PTE) microbeam resonator in the context of Euler-Bernoulli beam theory assimilating the nonlocal stress theory. The heat transport equation for the present problem is framed in the context of memory-dependent Moore-Gibson-Thompson theory adjoining the memory dependent derivative within a slipping interval. The thermoelastic distribution as well as vibrations for thermal moment and thermal deflection for a simply supported microbeam resonator is derived invoking the Laplace and finite Fourier sine integral transforms. In order to arrive at the solutions for thermoelastic vibrations of thermal moment and deflection in the real space-time domain, inversion of the finite Fourier transform has been performed analytically whereas the inversion of the Laplace transform is carried out numerically using the method of Zakian. In order to illustrate the numerical estimates, a PTE material of Lead Zirconate Titanate (PZT-5A) is considered. The main outcome of this research is to highlight how without the piezoelectric effect, oscillation amplitude rises sharply at all time-scales but stabilizes over longer periods. Also, how a higher time-delay parameter can increase oscillation magnitude in thermal moment and deflection, has been focused. Also, how the non-locality of the beam can reduce thermal moment significantly, with minimal effect on deflection, is mentioned. A comparative study between piezoelectric material with the material in absence of piezoelectric effect has been reported.
Inertio-elastic instability of functionally graded nanotube-reinforced composite disks
Authors: Yildirim Sefa , Tutuncu Naki
Published: November 2024

Rotational elastic instability of annular members is an important phenomenon which may lead to the destruction of structures. The instability analysis of rotating disks made of carbon nanotube reinforced composite (FG-CNTRC) has been presented. This study is the first to investigate the rotational instability of FG-CNTRC disks, providing new insights into the design of high-stability rotating structures. The rotating disk mounted to rigid shaft has variable-thickness and the function of CNT distribution along the radial coordinate may be uniform or functionally graded. The refined rule of mixture approach is used to obtain the material properties of composite where efficiency parameters are considered. The actual centrifugal force with radial displacement is taken into account and the burst velocities at which instability observed are obtained. The theory used in the analysis is plane elasticity and the governing differential equations of the problem have variable-coefficients where the analytical solution may not be available. Complementary Functions Method, which is a powerful numerical solution scheme, is implemented into the analysis and high accuracy with few collocation points are achieved using non-dimensional parameters. The influences of CNT distribution pattern, volume fraction of CNTs and variations of thickness profiles on the burst velocities of disk are examined. It is revealed that CNT addition to the isotropic polymer has a stabilizing effect on the rotating disk by increasing the burst velocity and the most effective parameter is the CNT distribution pattern. Considering all distribution patterns, the FG-V pattern yields the most stable disk design. Validation of the results is done using analytical solution which is only available for uniformly distributed CNTRC with the hyperbolic thickness profile.
Metabolomics reveals that phosphatidylethanolamine can alleviate the toxicity of silica nanoparticles in human lung A549 cells
Authors: Chen Shuang , Liu Chengzhi , Yang Yifan , Chu Jiangliang , Yuan Beilei , Wang Zhe
Published: November 2024

Silica nanoparticles (SiNPs) are widely utilized in occupational settings where they can cause lung damage through inhalation. The objective of this research was to explore the metabolic markers of SiNPs-induced toxicity on A549 cells by metabolomics and provide a foundation for studying nanoparticle-induced lung toxicity. Metabolomics analysis was employed to analyze the metabolites of SiNPs-treated A549 cells. LASSO regression was applied for selection, and protective measure experiments were conducted to validate the efficacy of selected potential toxicity mitigators. After SiNPs treatment, 23 differential metabolites were identified, including lipids, nucleotides, and organic oxidants. Pathway analysis revealed involvement in various biological processes. LASSO regression further identified six metabolites significantly associated with SiNPs toxicity. Notably, phosphatidylethanolamine (PE (14:1(9Z)/14:0)) showed enrichment in six significant metabolic pathways and with an AUC of 1 in the ROC curve. Protective measure experiments verified its protective effect on A549 cells and demonstrated its considerable inhibition of SiNPs-induced cytotoxicity. This study elucidated SiNPs-induced cytotoxicity on A549 cells and identified PE as a potential toxicity mitigator. These findings contribute to understanding the mechanisms of nanoparticle-induced lung toxicity and inform occupational health preventive strategies.
A Comprehensive Model of Community Violence Exposure Outcomes Using an Ecological Systems Framework
Authors: Wamser Rachel A. , Thomsen Kari N. , Walker Hannah E. , Howell Kathryn H.
Published: November 2024

Community violence (CV) is associated with negative psychosocial outcomes, such as posttraumatic stress symptoms (PTSS) and anger; however, many individuals also exhibit resilience. Considering the multifinality of outcomes following CV and guided by Bronfenbrenner’s ecological systems framework, the current study sought to examine individual, microsystem, and exosystem level factors in relation to PTSS, anger, and resilience. Participants were 536 emerging adults ( Mage = 20.13; SD = 1.81, range = 18–25) recruited from two universities. Three hierarchical linear regression models were conducted, one for each dependent variable (i.e., PTSS, anger, resilience). Block 1 included the covariates of recruitment site and age. Block 2 added individual-level factors (i.e., gender, race, income, CV exposure, other trauma exposure, code of the streets [COS] beliefs, religiosity), Block 3 added microsystem-level factors (i.e., parental monitoring, social support), and Block 4 added exosystem-level factors (i.e., community cohesion, community disorder). Identifying as female, higher levels of CV and other trauma exposure, and lower levels of social support were associated with greater PTSS. Recruitment site, more cumulative trauma, stronger endorsement of COS beliefs, lower levels of social support, and higher levels of community disorder were associated with higher levels of problematic anger. Higher income, identifying as a racial minority, higher levels of CV, more religiosity, higher levels of social support, and greater community cohesion were associated with more resilience. These findings highlight the importance of examining ecological systems concurrently. Individual- and microsystem-level variables may be key targets and should be considered in intervention and prevention services for emerging adults exposed to violence.
The Impact of the COVID-19 Pandemic on Police Involvement in Mental Health Calls for Service
Authors: Tartaro Christine , Lu Ruibin
Published: November 2024

The onset of the COVID-19 pandemic not only threatened individuals’ physical health but also caused a serious strain on mental health and access to care. Analyzing 4 years of data from 2019 through 2022, this study examines whether the frequency of mental health calls for service and police-initiated stops for mental health reasons changed over the course of the COVID-19 pandemic. Using interrupted time-series analysis, the results show that police involvement in mental health care was significantly affected by the COVID-19 pandemic. However, different changes were observed between dispatched calls for service and police-initiated stops for mental health reasons.
Flange Size Matters: A Comparative Pilot Study of the Flange FITSTM Guide Versus Traditional Sizing Methods
Authors: Anders Lisa A. , Mesite Frem Jeanette , McCoy Thomas P.
Published: November 2024

Background:

Pumping is a common practice in the United States, but it can be uncomfortable and lead to concerns about milk supply. The fit of the flange, or breast shield, used while pumping can contribute to or alleviate these problems. Flanges are available in a wide variety of sizes, and there are inconsistencies in guidance provided by healthcare providers and pump manufacturers for parents choosing a size. There have been no studies comparing different methods of sizing in terms of comfort and milk output.

Research Aims:

The aim of this research was to examine differences in milk output and comfort using two methods of flange sizing.

Method:

A within-subject cross-over design with a convenience sample of parents exclusively feeding their own human milk was used to compare comfort and milk yield between using smaller-fit and standard-fit flanges. Participants pumped for 1 week with each set of flanges and recorded milk output and comfort outcome measures. Data were collected on participant demographics, nipple measurements, and flange sizes used.

Results:

When compared to the newer small-size fitting, participants using the standard fit flanges had significantly less milk output (mean difference = −15.0 g, 95% CI [−25.0, −5.0], d = −0.51, p = 0.004) and less comfort (mean difference = −1.2, 95% CI [−1.6, −0.91], d = −1.23, p < 0.001).

Conclusion:

Flange fitting is a process that should be individualized to the patient and may require a trial of one or more sizes during a pumping session. Smaller sizes determined using this individualized process and starting with nipple tip measurement may be used without compromising milk output or comfort.
Breastfeeding Intentions, Attitudes, and Knowledge Among Medical Students in Croatia
Authors: Franić Sara , Čatipović Marija , Zakarija-Grković Irena
Published: November 2024

Background:

Medical students should have adequate knowledge and positive attitudes toward breastfeeding to support breastfeeding dyads. No studies in Croatia have explored breastfeeding knowledge, attitudes or intentions among medical students.

Research Aim:

To investigate breastfeeding knowledge, attitudes and intentions among medical students at the University of Split School of Medicine.

Methods:

A cross-sectional study was conducted from March to April 2023, using online and written questionnaires. All medical students without children were eligible to participate. The validated Breastfeeding Intentions, Attitudes, and Knowledge Questionnaire (BIAKQ) was used. Sociodemographic data were collected. Analysis was conducted using descriptive statistics, t tests, and Mann-Whitney U test.

Results:

A total of 357 medical students participated (response rate 64.1%). There was no significant difference between preclinical and clinical students. Students who attended the elective “Breastfeeding Medicine” demonstrated significantly more positive attitudes toward breastfeeding (Mean Rank = 215.62) than those who did not attend (Mean Rank = 173.58; U= 5468.50, p = 0.010); however, no significant difference was found in knowledge or intentions. Female students had significantly more positive attitudes compared to male students (Mean Rank = 189.47 vs. Mean Rank = 150.55, U = 9796.50, p = 0.001), whereas male students expressed significantly more positive intentions ( M = 36.97, SD = 5.26 vs. M = 34.44, SD = 5.86, t = −3.69, p = 0.002). The mean knowledge score was 11.92 ( SD = 1.43) out of 13 points. Negative attitudes towards breastfeeding beyond 1 year and breastfeeding in public were found.

Conclusion:

Despite adequate breastfeeding knowledge, some medical students demonstrated negative attitudes and intentions toward breastfeeding. Including breastfeeding education into core medical subjects focusing on the importance of breastfeeding for maternal and infant health and the risks of formula feeding could help improve attitudes, especially during the clinical years. It would also be important to address prevailing prejudices.
Finite element static analysis of functionally graded sandwich beams with porous core resting on a two-parameter elastic foundation based on quasi-3D theory
Authors: Mohamed Ibrahim , Kahya Volkan , Şimşek Sebahat
Published: November 2024

This paper presents for the first time an investigation into the static characteristics of FG sandwich beams with porous ceramic core and sandwich beams with FG porous core resting on a two-parameter Winkler-Pasternak elastic foundation using a new three-node higher-order finite element model with five degrees-of-freedom per node based on quasi-3D deformation theory, that accounts both the effects of transverse shear and normal deformations. The beams are subjected to uniformly distributed loads, and their material properties vary gradually through the thickness according to the power-law distribution. The governing equation of motion is derived from Lagrange’s equations. Uniform, symmetric, and asymmetric porosity patterns are considered. The accuracy of the proposed model is verified through comparisons with existing results. A comprehensive parametric study is carried out to explore the effects of various parameters such as boundary conditions, skin-to-core thickness ratio, power-law index, slenderness, porosity, and elastic foundation parameters on the displacements and stresses of FG sandwich beams. Benchmark results presented in this study can serve as a reference for future research endeavors on FG sandwich beams with porous cores.
Formation and properties of niobium silicide coatings on Nb-Ta alloy substrate
Authors: Pinto Beatriz A. , Chaia Nabil , D’Oliveira Ana Sofia C. M.
Published: November 2024

Niobium silicide coatings have been noted in the aeronautical and aerospace industries due to their high resistance to oxidation and creep. Despite these desirable properties, there is a need for further improvements to make them more applicable in demanding scenarios. This study investigates niobium silicide coatings processed on a Nb-22Ta alloy substrate by Double Pack Cementation method, to assess the influence of tantalum in coatings. The pack mixture was composed by 15% Si, 5% salt halide activator and 80% Al2O3, with NH4Cl and NH4F used as activators. The coatings were processed at 1000°C for 6 h. Analysis of the processed surfaces included a correlation with similar diffusion coatings processed on pure Nb under similar conditions. The results obtained by SEM and EDS revealed a low presence of Ta in the coatings, regardless of the halide activator used. Coatings processed with NH4F showed exclusive formation of NbSi2, while those processed with NH4Cl exhibited the presence of both Nb5Si3 and NbSi2. Nanohardness analysis indicated hardness levels of the niobium silicide coatings processed with NH4F similar to coatings processed with pure Nb substrate (1459 HV), different from the coatings processed with NH4Cl which demonstrate a much higher hardness close to the surface, around 2038 HV. Furthermore, coatings on Nb-22Ta exhibited better oxidation resistance at elevated temperatures, demonstrated by thermogravimetric analysis up to 1350°C. This behavior confirms s that silicide coatings are influenced by elements from the substrate Nb-22Ta that can be enhanced by processing conditions such as the activator in the pack mixture.
Planning and virtual simulation machining of multi-axis rough machining strategy for micro-integral impeller
Authors: Wang ZhiJie , Cao Yan , Zhao HaiYue , Yao Hui , Du Jiang , Kou Fan
Published: November 2024

It is discovered that the micro integral impeller’s NC programming is quite complex and that surface deformation and tool collision interference are easily caused by its torsional small channel, semi-closed construction, and complex free thin-wall surface. Furthermore, roughing has the longest processing time and the greatest quantity of material removal, making it easier to influence the next step in the processing process. Two machining techniques are suggested to address the NC roughing issue with this item. One tactic is to complete the impeller’s roughing by utilizing the benefits of a five-axis machine tool and the hierarchical parametric technique. The other is positioning five-axis roughing, which is roughing on a fixed five-axis region and is handled based on the flow path’s sub-area under the planned vector and area. The findings of the virtual simulation demonstrate that roughing in the five-axis fixed region may significantly increase machining efficiency and reduce machining time under the same machining circumstances. Lastly, tests are conducted to confirm the correctness of the virtual simulation model.
State recognition based adaptive cutting method for roadheader
Authors: Zhang Guotai , Shen Gang , Tang Yu , Li Xiang
Published: November 2024

To realize the adaptive swing velocity regulation for the roadheader under different coal and rock impedance, this paper proposes the control strategy based on the cutting state recognition. Firstly, based on the experimental platform, the current and acceleration sensor signals of different coal and rock impedances and swing velocities were measured to construct the cutting state dataset. Secondly, the k-means++ algorithm is used to extract the sudden data that can better reflect the working state. The distance evaluation technology (DET) is proposed for sensitive feature selection and KPCA algorithm is utilized for data fusion to obtain two-dimensional feature vector which can benefit to reducing the input dimension of the state classifier. Simultaneously, an improved whale algorithm is introduced to optimize the RBF neural network (RBFNN) for different cutting status recognition. The test results show that the cutting state identification accuracy of designed RBF classifier can reach 98.8%, which owns higher precision compared with other optimization models. Then, to improve the swing velocity tracking dynamics, the backstepping sliding mode cascade controller is designed and the multi-domain co-simulation showed the superiority of fast response and anti-disturbance. Finally, based on the presented adaptive cutting strategy, the actual experiments under mutational coal rock hardness conditions were conducted. The experimental results showed that the roadheader’s swing velocity can be autonomously adjusted within 0.5 s as the external cutting load varies, which demonstrates the effectiveness and feasibility of the method proposed.