Stress Theory Research Articles

High-thermal free vibration analysis of functionally graded microplates using a new finite element formulation based on TSDT and MSCT

Recent advancements in additive manufacturing (AM) have revolutionized the design and production of complex engineering microstructures. Despite these advancements, their mathematical modeling and computational analysis remain significant challenges. This research aims to develop an effective computational method for analyzing the free vibration of functionally graded (FG) microplates under high temperatures while resting on a Pasternak foundation (PF). This formulation leverages a new third-order shear deformation theory (new TSDT) for improved accuracy without requiring shear correction factors. Additionally, the modified couple stress theory (MCST) is incorporated to account for size-dependent effects in microplates. The PF is characterized by two parameters including spring stiffness () and shear layer stiffness (). To validate the proposed method, the results obtained are compared with those of the existing literature. Furthermore, numerical examples explore the influence of various factors on the high-temperature free vibration of FG microplates. These factors include the length scale parameter (), geometric dimensions, material properties, and the presence of the elastic foundation. The findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments. In addition, the findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments. In addition, the results of this research will have great potential in military and defense applications such as components of submarines, fighter aircraft, and missiles.

The role of stress mindset and academic buoyancy in school burnout in middle adolescence

ABSTRACT School burnout, defined as prolonged feelings of exhaustion, cynical attitude and inadequacy feelings towards schoolwork, can lead to mental problems during adolescence. To find effective ways to prevent burnout, this study examined the synergistic role of two positive personal resources, a stress-is-enhancing mindset and academic buoyancy in relation to school burnout dimensions. The participants were 932 Finnish middle-school 9th-grade (age = 14–15) students. The results of SEM revealed that academic buoyancy and stress-is-enhancing mindset were jointly negatively related to one dimension of school burnout, cynicism. However, the stress-is-enhancing mindset had an indirect effect on all dimensions (exhaustion, inadequacy and cynicism) via academic buoyancy. The findings highlight their joint effect and especially the role of academic buoyancy in relation to school burnout. The implications of the results to burnout prevention and stress theories are discussed.

CHALLENGES AND COPING STRATEGIES OF AUTISM PARENTING: A SYSTEMATIC LITERATURE REVIEW OF PARENTS’ AUTOETHNOGRAPHIES

Background and Purpose: Parents of autistic children face caregiving challenges, yet there is a dearth of research specifically analysing parents’ autoethnographies. This systematic literature review explores themes of challenges and coping strategies in autism caregiving, guided by the Transactional Theory of Stress and Coping (Lazarus & Folkman, 1984). Methodology: Following Kitchenham and Charters’ (2007) guidelines, a systematic literature search of autoethnographies by parents of autistic children was conducted using online databases. The search was guided by two questions: (1) What are the challenges faced by parents caring for their autistic children?; and (2) What are the coping strategies employed by parents in caring for their autistic children? Findings: Twelve autoethnographies were analysed. Themes regarding challenges included parents experiencing fears, feeling despair and facing barriers and stigmatisation. Coping strategies identified included parents seeking answers, having hopes, and gaining empowerment besides providing support. Limitations and future research directions were discussed. Contributions: This paper emphasises understanding challenges faced by parents of autistic children. It illuminates emotional and societal aspects of autism parenting, emphasising the necessity for tailored support systems. Additionally, it reveals parents' coping strategies, including empowerment and supporting others, indicating increased understanding of their children's autism and active facilitation of support networks. Keywords: Well-being, Autism parenting, Autoethnography, challenges, coping. Cite as: Bakar, R. A., Ghani, K. D. A., Aziz, N. I., & Mohamad, N. H. S. (2024). Challenges and coping strategies of autism parenting: A systematic literature review of parents’ autoethnographies. Journal of Nusantara Studies, 9(2), 340-370. http://dx.doi.org/10.24200/jonus.vol9iss2pp340-370

How the perfectionistic climate of a sports team predicts the athletic performance of elite athletes: a case study of the CUBAL women's basketball team.

In competitive sports, understanding how the perfectionistic climate within teams influences the performance of elite female athletes can provide valuable insights for enhancing coaching practice and athletic achievement. Based on the cognitive appraisal theory of stress, this study constructs a dual-path model using stressors and coping strategies as mediators, referred to as the Perfectionistic Climate on Athletic Performance model (PCPM). The study explores the predictive role of the perfectionistic climate within sports teams on the athletic performance of elite female basketball players. The empirical study the relationships among the variables in the model using a sample of 125 core players from the top-level women's basketball teams in the 24th CUBAL24 tournament in 2022. A Structural Equation Modeling (SEM) analysis was conducted using AMOS 20.0, primarily employing the bias-corrected Bootstrap method to test the dual-path model. The findings reveal double-edged paths towards a perfectionistic climate on athletic performance. In the positive pathway, a perfectionistic climate can positively predict athletic performance through challenge-related sources of stress and positive coping strategies. In the negative pathway, a perfectionistic climate can negatively predict athletic performance through threat-related sources of stress and negative coping strategies. Coaches need to pay attention to athletes' cognitive evaluations of the perfectionistic climate as a source of pressure. By setting challenging goals, coaches can guide athletes to view the perfectionistic climate of the sports team as a source of challenging pressure, thus unleashing their potential. Coaches should actively guide athletes in coping with the pressure brought about by the perfectionistic climate, enhancing their ability to handle stress. This will enable athletes to better adapt to the team's perfectionistic climate and further improve individual and team athletic performance.

Assessing gradient parameters for damage control in notched plates: Finite element analysis of locally functionally graded materials using the Gurson-Tvergaard-needleman (GTN) model

This study investigates functionally graded materials (FGMs) as reinforcement for notched plates prone to crack propagation. Using a novel meshing technique and the Gurson-Tvergaard-Needleman damage model within ABAQUS-Explicit, we explore how various gradation parameters affect material damage under stress. The model, incorporating Von Mises stress theory and Voce hardening law, simulates plastic flow and progressive damage from void dynamics. Validated against experimental data, our findings reveal that local gradation parameters significantly influence void damage and structural performance of notched components. This research provides crucial insights into FGMs' potential to enhance structural integrity in engineering applications involving notched structures.

Vibrations in piezothermoelastic micro-/nanobeam with voids utilizing modified couple stress theory

The present study examines the vibrations in micro- and nano-piezothermoelastic beams with voids. In this work, the modified couple stress theory is employed to generate closed-form formulas for deflection, volume fraction, electric potential and temperature distribution. The effects of voids, modified couple stress, beam dimensions and electric potential on energy dissipation (thermoelastic damping) are examined for beams under various boundary conditions. We have established analytical formulas for frequency shift, attenuation and thermoelastic damping. MATLAB software is used to get numerical results and exhibit them visually.

Buckling analysis of medical guidewires based on the modified couple stress theory

Buckling analysis of medical guidewires based on the modified couple stress theory

How do you treat your ‘big fish’? The joint effect of perceived subordinates’ overqualification and managers’ personalities on knowledge hiding

ABSTRACT By integrating the cognitive appraisal theory of stress and coping and the conservation of resources theory, this paper explores the interactions and the mechanism of perceived subordinate’ overqualification and personalities on managers’ knowledge hiding in the service industry. Using a multi-stage research design supported by data collected from upscale hotels in China in three waves (n = 453), the results suggests that when perceiving subordinates’ overqualification, managers with highly cooperative personality decrease knowledge hiding. Conversely, managers with highly competitive personality increase knowledge hiding. Moreover, self-protection motivation mediates the positive relationship between perceived subordinates’ overqualification and managers’ knowledge hiding. This study not only contributes to a better understanding of the psychological mechanism of managers’ knowledge hiding but also responds to the call for multilevel effects research on overqualification. The study’s findings can also serve as important references for hotels’ human resources practices to maximize the values and contributions of human capital.

Bending responses of graphene nanoplatelets reinforced sandwich cylindrical micro panel with piezoelectric layers

Bending responses of a nanocomposite-reinforced cylindrical panel are studied in this article. A cylindrical shell panel is assumed in micro scale and sandwiched by piezoelectric layers. In this article, a micro-size dependent theory named as the modified couple stress theory (MCST) is analytically employed and the kinematic relations are extended through employing shear deformable model in order to investigate the electroelastic bending responses of a three-layered micro-shell bonded between smart layers subjected to an applied voltage, external and internal pressures. The micro-shell is assumed rested on a two parametrically elastic foundation. In order to develop constitutive relations, the mixture’s rule as well as Halpin-Tsai model are utilized to compute governing equations. Electroelastostatic responses are analytically obtained through trigonometric functions. A large extended parametric analysis is presented to explore deflection of the micro-shell with a change in applied voltage, thickness of the piezoelectric layer to radius, length to radius ratio, different characteristics of nanoplatelet reinforcement for the both external and internal pressure. The proposed composite electromechanical structure may be used in the smart structures and systems. A controllable system can be suggested through the usage of graphene nanoplatelets because of flexibility and affecting parameters.

Size-dependent vibration analysis of porous 3D-FG microshells in complex thermal environments using a neural network enhanced finite element model

This work aims to investigate the vibration behavior of porous three-directional functionally graded (3D-FG) microshells in thermal environments, where both mechanical and thermal material properties vary along three spatial directions following a power-law distribution, based on the modified couple stress theory (MCST). An isoparametric thermal element is employed for uncoupled heat conduction analysis, followed by dynamic analysis using a penalty solid element with three translation degrees of freedom (DOFs) and three rotation DOFs per node. However, due to the strong nonlinearity of the temperature field in 3D-FG microshells, obtaining exact temperature values at integration points in dynamic analysis requires a pretty dense mesh of the solid element. To overcome this issue, a back propagation (BP) neural network is utilized to predict the temperature field for various gradient indexes, enhancing the efficiency and precision of temperature distribution calculation. Numerical results demonstrate the effectiveness of the neural network enhanced finite element model. Furthermore, the effects of the material length scale parameter (MLSP), temperature difference, and gradient indexes on the natural frequencies are investigated. It is shown that higher structural stiffness weakens the impact of temperature difference on the frequency.

Sociocultural Implications in the Development of Early Maladaptive Schemas in Adolescents Belonging to Sexual and Gender Minorities.

Culture is a central theme across various theories and disciplines, influencing behavior and self-perception through interactions within social groups, families, and legal systems. This influence extends to the general population and particularly impacts sexual and gender minorities (SGMs), resulting in minority stress that contributes to mental health issues and the development of Early Maladaptive Schemas (EMSs). Adolescents within these groups face typical developmental stressors-such as hormonal changes and societal pressures-compounded by prejudice, increasing their vulnerability to depression, anxiety, stress, substance abuse, and eating disorders. Despite these challenges, Schema Therapy (ST) lacks comprehensive studies on the sociocultural aspects influencing EMS acquisition in SGM adolescents. This theoretical review aims to fill this gap by exploring the impact of society and culture on EMS development within SGM adolescents. We recognize the broad spectrum of cultural influences and emphasize the importance of cultural sensitivity and diversity. This review specifically addresses how societal and cultural dynamics impact SGM individuals, acknowledging that while ethnic or other cultural factors are not the focus of this paper, they merit future research. This manuscript will discuss central topics and their impact on LGBTQIA+ youth, including (1) the background (definition of culture, lack of studies on ST focusing on culture, and studies on adverse psychological outcomes), (2) minority stress theory and prejudice against sexual and gender diversity (distal and proximal stressors and sociocultural aspects), (3) EMSs and unmet emotional needs, (4) ST affirmative strategies (working with schema modes, imagery rescripting, chair work, and photo techniques), and (5) final considerations (limitations and research agenda).

Liberal policies does not mean equitable policies: Latinx families' experiences navigating social policies in Oregon and California.

The United States government has implemented various social policies (e.g., Medicare) to support children and families (U.S. Department of Health and Human Services, 2023). An emerging body of research seems to indicate that many of these programs are being underutilized by Latinx families even though they are sorely needed. Latinx families are often framed as undeserving, taking advantage of social policies, and as a criminal threat to the United States (Baranauskas & Stowell, 2022). Drawing on cultural stress theory (Salas-Wright & Schwartz, 2019), the present study explores how the deficit framing of Latinx families influences how they navigate social policies. This study draws on data from four qualitative projects across Oregon and California that explored the experiences of Latinx families accessing services to support their families. Findings indicate that Latinx families experience multiple stressors when navigating social policies or programs (e.g., shame/fear and racism) for their families. These stressors discourage Latinx families from accessing social programs, which exacerbates disparities in the health, development, and learning of Latinx children and families. Findings from this study can further inform advocacy efforts to create meaningful systemic changes that reduce inequities and call out discrimination/racism within our policy system. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A longitudinal examination of appraisal, coping, stress, and mental health in students: A cross-lagged panel network analysis.

In their seminal Transactional Theory of Stress, Lazarus and Folkman described a complex adaptation mechanism that involves appraisal and coping processes that lead to the subjective experience of stress. In this study, we examined the temporal order of all components of this theory using a cross-lagged panel analysis. A sample of 354 students (62.10% female, mean age=20.63y.o.) participated in a 5-week study and completed weekly self-reported measures of prospective appraisal, coping, core burnout, and mental health (i.e. depression, anxiety, and stress). Using cross-lagged panel network analyses, we analyzed how each measured variable is predicted by all variables from the previous measurement moment. Convergent with the transactional stress theory, we found that threat appraisals and negative self-perception predicted future anxiety and depression. Contrary to expectations, core burnout and somatization emerged as significant predictors of poor mental health outcomes, suggesting a self-perpetuating spiral. Furthermore, our study highlighted the importance of recognizing the bidirectional connections between appraisals, coping strategies, and mental well-being.

Cultural stress among immigrants in the workforce.

Previous research has investigated cultural stress and well-being among individuals such as Hispanic college students and immigrants from other countries. However, there is a need to explore the impact of cultural stress among immigrants with a focus on the workforce. Drawing from cultural stress theory, we present a theoretical framework that considers workplace context while exploring strategies that may mitigate the impact of cultural stress in the workplace, such as promoting diversity and inclusion, addressing biases and discrimination, and supporting employee mental health. We provide actionable steps that can guide leaders to work toward a workplace where individuals develop a sense of belonging. This article provides a novel perspective on workplace diversity and inclusion that emphasizes the importance of considering cultural context in understanding and addressing workplace stress, with implications for psychology in the workplace. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Competitive federalism, individual autonomy, and citizen sovereignty

AbstractThe paper examines the theory of competitive federalism, focusing specifically on Hayek's and Buchanan's significant contributions to this theory. Looking at the rivalry between sub‐units in federal systems and drawing an analogy between market competition and intergovernmental competition, the theory of competitive federalism stresses the critical role viable exit options play as operating force in both arenas. The principal claim argued for in this paper is that by exclusively focusing on exit in its territorial dimension, the theory of competitive federalism obfuscates the fact that “exit” can mean two critically different things in federal systems. It can mean exiting from the territory over which a government exercises its assigned authority, and it can mean exiting from a polity in the sense of giving up one's membership status in the respective community. The paper discusses the nature, the significance, and the implications of the difference between these two kinds of exit.

The Effects of Illegitimate Tasks on Task Crafting and Cyberloafing: The Role of Stress Mindset and Stress Appraisal.

Previous studies have mainly focused on the detrimental effects of illegitimate tasks as ubiquitous workplace stressors while ignoring the appraisal measures for such tasks. The term "illegitimate" is used by employees to describe the alignment of a task with their job role rather than the inherent qualities of the task itself. Thus, drawing on the transactional theory of stress, this study examines the moderating effect of the stress mindset on the relationship between illegitimate tasks and the appraisal of such tasks. On this basis, this study further explores when cognitive appraisal mediates the effects of illegitimate tasks on coping behaviors (task crafting and cyberloafing). Data were collected from 285 employees from an energy company in Shandong, China, by using a time-lagged research design. The findings indicate that employees react differently to illegitimate tasks depending on their stress mindset. Specifically, for employees with a stress-is-enhancing mindset, illegitimate tasks induce their challenge appraisal, which leads to task crafting. In addition, illegitimate tasks induce hindrance appraisal in employees with a stress-is-debilitating mindset, which leads to cyberloafing. In practice, this research study suggests that when illegitimate tasks cannot be eliminated, organizations should consider employees' stress mindset when assigning such tasks.

Nonlinear thermal flutter of variable angle tow composite laminates in supersonic airflow

Compared with traditional composite materials, variable stiffness composite materials with curvilinear fiber paths have higher design flexibility and the potential to improve structural efficiency. In view of this, the nonlinear flutter characteristics of Variable Angle Tow (VAT) composite laminates with thermal effect in supersonic airflow are investigated in this paper. The proposed panel flutter model is developed based on the von Kármán large deformation plate theory. The thermal stress is approximated according to the quasi-steady thermal stress theory, whilst the aerodynamic pressure is calculated based on the first-order piston theory. The aerothermoelastic equations of motion are first established using Hamilton’s variational principle, and the Rayleigh-Ritz method is then applied to solve the governing equations in the space domain. The time-domain nonlinear equations are solved through the fourth-order Runge-Kutta method. The accuracy and convergence of the proposed method are verified through the comparisons with the results available in the literature. The effects of several parameters such as fiber orientation angle, thermal load, and aerodynamic pressure on the nonlinear flutter responses of VAT laminates are comprehensively discussed. Several dynamic behaviors of VAT laminates, including stable flat, buckled, Limit Cycle Oscillation (LCO), multi-periodic motion, quasi-periodic motion, and chaotic motion, are revealed by using the time history, phase portrait, Poincaré map, and bifurcation diagram. The results presented herein may be beneficial for the design of VAT laminates in supersonic airflow.

Mathematical Solution for Vibrational Response of Shear and Normal Deformable Advanced Metal Foam CMBS Treated with Nanocomposite Actuators

This research focuses on examining the vibrational properties of intelligent curved microbeams (CMBs) that incorporate metal foams and are enhanced with carbon nanotubes-reinforced piezoelectric (CNTRP) actuators. An advanced four-variable theory for shear and normal deformation is applied in the polar coordinate framework to investigate the microstructure, thereby negating the need for a shear correction factor. Additionally, the modified couple stress theory (MCST) is utilized to account for scale effects. The structural attributes exhibit thickness-dependent alterations following predefined functions. The governing equations of motion are deduced using Hamilton’s principle. In instances where the structure has simply supported ends, Fourier series functions are utilized to solve these equations. The outcomes are cross-validated in contradiction with previously documented works with more straightforward setups. The inquiry investigates the effects of critical parameters on the vibrational response of the structure. The results are corroborated in simpler scenarios using existing data in the literature to ensure accuracy.

Dynamic Response of Advanced Lightweight Porous Plates Integrated with Nanocomposite Face Sheets Resting on Elastic Substrate

This study centers on the analysis of a scale-dependent microplate configuration characterized by a porous core enveloped by nanocomposite patches embedded with graphene nanoplatelets. The microplate’s behavior is explored within a humid environment to comprehend the effects of moisture variations on its dynamic performance. Additionally, the microplate rests upon a Kerr foundation, a three-parameter elastic substrate. The material properties of all three layers are contingent upon thickness. To enhance precision, an innovative quasi-three-dimensional shear and normal trigonometric theory is employed, elucidating the kinematic interrelations of the microstructure. Notably, this novel theory accommodates the presence of transverse normal strain. For a comprehensive analysis of size influences, the modified couple stress theory is harnessed. This theory integrates a material length-scale parameter to anticipate outcomes at the micro-scale. By invoking Hamilton’s principle, differential motion equations are deduced and subsequently solved analytically. The investigation centers on probing the consequences of varied parameters on the natural frequencies. The findings underscore that the incorporation of GPLs amplifies the microplate’s stiffness, thus elevating its natural frequencies. In contrast, an escalation in the porosity index leads to a reduction in natural frequencies.

The effect of STARA awareness on hotel employees' turnover intention and work engagement: the mediating role of perceived organisational support

PurposeThe proliferation of Smart Technologies, Artificial Intelligence, Robotics, and Algorithms (STARA) in the tourism and hospitality (T&H) industry has been shown to trigger negative employee behaviour associated with awareness of these technologies. This study expands the existing literature on technology and organisational behaviour from the perspective of hospitality employees based on a dual appraisal of STARA awareness.Design/methodology/approachThe sample included 324 Turkish hotel employees, and the analysis was conducted through partial least squares structural equation modelling (PLS-SEM).FindingsResults revealed the negative impact of STARA awareness on job outcomes among hotel employees. STARA awareness negatively affected the psychological relationship between individuals and organisations. Despite these findings, when perceived as a companion that could support employees' career development, STARA technologies increased employees’ work engagement.Practical implicationsOrganisational support plays a critical role in decreasing employees’ fear of technological unemployment. Hotel managers can increase employees' commitment to the organisation by helping them feel valued and supported. However, the support they give to employees will not always work. While more optimistic employees are warmer toward the organisation, depressed employees may not recognise the value the organisation gives them. Hence, managers should strive to offer personalised assistance that addresses the distinct requirements and worries of individual employees.Originality/valueThe research provides a two-sided assessment, extending the one-sided negative perceptions of employees towards STARA technologies. The research is grounded in the Transactional Stress Theory and provides significant implications for the Job Demands-Resources Theory, Person-Organisation Fit Theory, and Self-Determination Theory.