Stress Behavior Research Articles

Destructive and Constructive Interparental Conflict, Parenting Stress, Unsupportive Parenting, and Children’s Insecurity: Examining Short-Term Longitudinal Dyadic Spillover and Crossover Process

Based on emotional security, stress, and spillover and crossover theories, this study aimed to examine the indirect pathways between destructive and constructive interparental conflict, parenting stress, unsupportive parenting, and child insecurity six months later. Using data from two time points beginning when Korean children (N = 159) were approximately 3–5 years old, two dual-mediation models of the relevant variables were constructed. The results indicate that destructive conflict is associated with higher levels of parenting stress, whereas constructive conflict is associated with lower levels of stress. Furthermore, mothers’ and fathers’ parenting stress influenced their own unsupportive parenting behaviors, which, in turn, influenced their children’s insecurity, suggesting a spillover effect. However, the crossover effect and mediation analyses provided partial support for various pathways of the hypotheses. By examining both destructive and constructive conflict, including both maternal and paternal variables, and examining not only spillover but also crossover effects, this study highlights that while constructive conflict may reduce parental stress and unsupportive parenting behaviors, the negative effects of destructive conflict may affect children more strongly. Particularly, by examining the spillover and crossover effects in the unique cultural context of Korean families, this study provides important insights into interparental conflict’s impact on child development.

Impact of job insecurity, job stress and negative emotions on counterproductive work behaviour among academic employees in Ghana

The antecedents of counterproductive work behaviour (CWB) in the higher education sector have remained unexamined in available literature. Moreover, the impact of job insecurity, job stress, and negative emotions on the occurrence of CWB within the academic context have hardly been interrogated. This study therefore, aimed at investigating the impact of job insecurity, job stress and negative emotions on CWB and further examining the mediating role of job stress and negative emotions in the occurrences of CWB among academics. Data was collected from 716 academics in Technical Universities in Ghana using self-reported questionnaires with close-ended questions and a convenient sampling technique. Confirmatory Factor Analysis was conducted to verify the measurement structure of the constructs. Structural Equation Model was employed to test the hypotheses in the conceptual model. The result showed a statistically significant direct effect of job insecurity, job stress and negative emotions on the occurrence of counterproductive work behaviour among academics. It was further revealed that there is a positive relationship between job insecurity and job stress, with job stress partially mediating the relationship between job insecurity and counterproductive work behaviour. Furthermore, negative emotions acted as a partial mediator in the relationship between job stress and counterproductive work behaviour. The findings have implications for higher education institutions in taking steps to address job insecurity, job stress, and negative emotional experiences of academics to mitigate counterproductive work behaviour among academics.

Influence of in-situ hammering on microstructural, mechanical and residual stress behaviour of inconel 718 during wire arc additive manufacturing

Influence of in-situ hammering on microstructural, mechanical and residual stress behaviour of inconel 718 during wire arc additive manufacturing

Work ability and psychosocial work stress - predictors of retirement intention among older teachers.

Many teachers worldwide retire early for health or personal reasons. Predictors could help to identify teachers at risk in order to counteract this development. The study therefore investigates whether the intention to retire can be predicted by work ability, psychosocial work stress and work behaviour. The data came from a representative cross-sectional study of German secondary school teachers (N = 18 971). The analyses included 1496 full-time teachers aged ≥50 years (58% female). Teachers were assigned to 1 of 2 groups based on their intention to take early or regular retirement. A binomial regression model was used to analyze the predictive power of the intention to retire for the following factors: work ability index (WAI) - factor 1, effort-reward ratio (ER ratio), overcommitment (OC), age and gender. In addition, a qualitative analysis of the teachers' suggestions was carried out regarding which measures would make the regular retirement age attainable. Half (49%) of the teachers intended to retire early, with the proportion of women being around twice as high (67%) as men (33%) (d = 0.37). The analyzed predictors explained a total of 22% of the variance. The WAI factor 1 proved to be the most important predictor (variance explanation: 14%). Effort-reward ratio and OC each contributed around 10% to the variance explanation of the retirement intention. The probability of taking early retirement increased with decreasing work ability, increasing ER ratio and a high tendency to overcommit; age and gender were of secondary importance. Teachers suggested a reduction in compulsory hours (46%), relief from extracurricular tasks (45%) and smaller classes (29%) as decisive measures for achieving regular retirement. Work ability index factor 1, ER ratio and OC could be used as part of occupational health prevention programmes to identify and advise older teachers at risk who need support. Int J Occup Med Environ Health. 2024;37(5).

The regulative role and mechanism of BNST in anxiety disorder.

Anxiety disorders, common yet impactful emotional disturbances, significantly affect physical and mental health globally. Many neuron circuits are associated with anxiety regulation like septo-hippocampal loop, amygdala(AMYG), bed nucleus of the stria terminalis (BNST), ventral hippocampus (vHPC), and brain regions like medial prefrontal cortex (mPFC). However, the concrete mechanism of anxiety disorder in BNST is relatively unknown. Recent research showed BNST plays a critical role in modulating anxiety owing to its anatomical location and special circuit characteristics, which are considered to be a hub in the limbic system regulating anxiety. BNST consists with multiple subregions, which can project separately into different brain regions and exert projecting independently to various brain regions with distinct regulatory effects. Moreover, multiple signal pathways in BNST are reported to play significant roles in regulating anxiety and stress behavior. This review briefly describes anxiety disorders and subdivisions and functions of BNST, focusing on the main neural circuits that serve as fundamental pathways in both the genesis and potential treatment of anxiety disorders and the molecular mechanism of BNST on anxiety. The complexity of structures and mechanisms has facilitated the development of imaging techniques. Innovative multimodal imaging techniques, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), have non-invasively illuminated BNST activities and their functional connections with other brain areas. These methodologies provide a deeper understanding of how BNST responds to anxiety-inducing stimuli, offering invaluable insights into its complex role in anxiety regulation. The continued exploration of BNST in anxiety research promises not only to elucidate fundamental neurobiological mechanisms but also to foster advancements in clinical treatments for anxiety disorders.

Low-cost rolling ball viscometer for the evaluation of Newtonian and shear-thinning fluids

Abstract This article describes the design and testing of a low-cost automatic rolling-ball viscometer. The device has been manufactured from three-dimensional printed parts and conventional and affordable mechanical and electronic components. It is controlled by an Arduino MEGA with a custom code that includes manual and automatic measuring modes. Both the type of viscometer and the models used are, in principle, valid for Newtonian and power-law fluids. However, measurement and calculation procedures have been developed that also makes it possible to determine the viscosity of Herschel–Bulkley fluids that might exhibit a yield stress behaviour within the range studied. By these procedures, viscosity values have been obtained for model fluids – Newtonian, power-law, and Herschel–Bulkley fluids – and compared to those obtained with a commercial rotational rheometer. The proposed setup and measuring method have thus proven to provide very reasonably accurate viscosity values for a low-cost device.

The Relationship Between Perceived Stress and Aggression Behavior Among Individuals with Major Depressive Disorder (MDD)

This study examines how perceived stress impacts aggression in individuals diagnosed with Major Depressive Disorder (MDD), specifically looking at the variations between genders. The study utilizes a quantitative questionnaire to investigate the correlation between stress and aggression, as well as the factors that exacerbate this relationship, including the reciprocal linking of stress and aggression. Perceived stress and aggression exhibited a substantial and advantageous correlation (r = 0.62, p < 0.01), suggesting that an increase in aggression was linked to elevated stress levels. 78% of males and 58% of females admitted to frequently exhibiting aggression, while males reported engaging in aggressive behaviors more frequently than females. A reciprocal relationship was discovered, in which escalated aggression led to elevated stress levels and increased stress caused heightened aggression (r = 0.54, p < 0.05), thereby establishing a detrimental feedback cycle. These results indicate that interventions aimed at reducing stress could be especially helpful in decreasing aggression in male MDD patients. This study enhances our comprehension of the dynamics between stress and aggression in MDD and highlights the significance of addressing these aspects in therapy.

Multi-stage load partitioning in additively manufactured Al6061+TiC nanocomposite characterized by in-situ neutron diffraction

Metal matrix composites (MMCs), combining metal matrix and ceramic particles, exhibit high mechanical strength and stiffness compared to conventional metallic materials. During fusion-based additive manufacturing (AM), MMCs undergo a rapid heating and cooling thermal history, which affects the interfacial bonding, thermal misfit stress and mechanical load transfer behavior between the metal matrix and particles, thus impacting the bulk mechanical performance. Here, we investigate the deformation dynamics and phase-specific load transfer in fusion-based AMed Al6061+TiC MMCs through in-situ neutron diffraction. By calculating the phase-specific lattice strains, a multi-stage load transfer and deformation behavior during uniaxial compression is revealed: (1) elastic deformation in Stage I for both phases; (2) sudden stress rebalance between two phases in Stage II, evidenced by a sudden decrease in Al lattice strain and increase in TiC; (3) active load carrying by both phases in Stage III, with both phases experiencing an increase in lattice strains. The deformation mechanism of each stage is deducted by correlating the evolutions of the interphase stresses and peaks’ broadening and intensity of the Al matrix. The local plastic deformation of the Al matrix near the phase interface is triggered and leads to stress rebalancing in Stage II. The global plastic deformation subsequently propagates throughout the Al matrix in Stage III, and the composite is further hardened through both dislocation multiplication and load transfer. The findings offer valuable insights into deformation and load-sharing behavior in AMed MMCs.

Enhanced adhesion strength of copper deposited epoxy composite films for chip substrates by tuning copper oxide and internal stress

Copper oxides and internal stress have an obvious influence on adhesion strength of copper deposited polymer composites. However, the effect of the evolution behavior of copper oxides and internal stress on adhesion force of chip substrates is no clear and rare far. Herein, the copper deposited epoxy-phenolic/silica composite film with different desmear time was fabricated by using wet chemistry and electrochemistry methods. The chemical structure, surface roughness, morphology, surface chemical state, crystal structure and adhesion strength of copper and epoxy resin substrate were characterized by scanning electron microscope (SEM), interference microscope, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The adhesion strength of samples is increased from 3 N/cm to 4.7 N/cm. The effect of the evolution behavior of copper oxides and internal stress on adhesion strength of copper deposited epoxy resin composite films at the interfaces was systematically investigated, the mechanisms and reason of increasing adhesion strength and interfacial adhesion failure for copper deposited epoxy resin composite substrates were revealed. This work will provide a guidance in theory and experiment to enhance interfacial adhesion force of epoxy resin composite films for advanced substrate in the future.

Prediction of transient thermal stress distribution in SOFC based on coupled computational fluid dynamics and thermodynamics modeling

Long-term stability and safety are two key factors for the application of solid oxide fuel cell (SOFC) technology, with thermodynamics playing a central role in influencing this stability. Thus, understanding the thermodynamic behavior within SOFC and how it will depend on the stack structure are very important, especially at the start and stop stages. In this study, a 3D calculated fluid dynamics model and thermomechanical coupling model based on the actual component structures are established. We place emphasis on understanding how these factors evolve during dynamic phases, shedding light on the transient thermal stress behavior of the SOFC. The influence of different interconnect structures on the thermal stress distribution is studied. The coupling calculation results show that the first principal stress of the electrolyte is significantly affected by the specific interconnect structure. Adopting cylindrical ribs instead of rectangular ribs, the thermal stresses of the SOFC components can be reduced by 13–25 %, respectively.

The influence of stress, social support and feminine values on the health behaviour of women in Hong Kong.

The relationship between feminine values, cultural values, stress, social support and health behaviour among women in Hong Kong was examined in a sample of 306 women aged 18-61 years (M = 34.77, SD = 10.43). Older age and weaker identification with Chinese cultural values were predictive of engagement with risky health behaviour, older age was also associated with lower perceived levels of stress. Further post-hoc analysis explored the mediating effect of Chinese values and stress on the relationship between feminine values and health behaviour, Chinese values and stress fully mediated the relationship between feminine values and engagement with risky health behaviour. Experiencing high levels of stress did not necessarily lead to engagement in health compromising behaviour. Incorporating cultural values into health promotion campaigns may be one approach to better engagement in health promotion behaviour.

Numerical study on temperature and thermal stress behaviors in silicon carbide heating elements within high-temperature annealing furnaces

In response to global sustainability goals, the transition from fossil fuel-based to electric silicon carbide (SiC) heating elements in continuous annealing furnaces is critical for reducing emissions, enhancing safety, and improving operational environments in the steel industry. This study investigates the cross-sectional temperature profiles and the resultant thermal stress of hollow cylindrical SiC heating elements under varied design conditions. To independently analyze the complex effects of multiple factors, both theoretical and numerical analyses were conducted using simplified boundary conditions in two dimensions, which closely simulate the actual temperature profiles observed in heaters within a continuous annealing line. The results indicate that the radial temperature gradient and resulting thermal stress in these elements are directly proportional to the surface heating load, with the maximum axial tensile stress occurring at the outer surface of the heater. Scenarios involving closely spaced multiple heaters or the introduction of cold steel strips lead to increased axial thermal stress due to additional circumferential temperature gradients. Conversely, the application of shield tubes, despite increasing the heater’s temperature, reduces thermal stress by homogenizing radiation within the tube. Consequently, optimizing heater configuration and operational conditions is essential in furnace design to effectively manage heaters’ temperature and thermal stress, thereby ensuring both efficiency and service longevity of the heating elements.

Experimental, modeling, and numerical simulation of ultrasonic assisted drilling of CFRP/Ti stacks

Carbon fiber reinforced polymer (CFRP) and Ti-6Al-4V alloy (Ti) stacks structures are increasingly utilized in aircraft load-bearing applications, where the quality of hole processing significantly impacts their connection performance. Conventional drilling (CD) methods for CFRP/Ti stacks often encounter challenges such as severe interface damage, high cutting forces, and excessive heat generation. This study investigates the application of ultrasonic-assisted drilling (UAD) on CFRP/Ti stacks by integrating finite element method (FEM) modeling with experimental approaches to analyze the machinability of these materials under different machining methods and parameters. A self-developed high-frequency vibration spindle was employed to process CFRP/Ti stacks using both CD and UAD techniques. The newly developed numerical model effectively elucidates the mechanical and thermal coupling involved in the machining process and the transfer behavior of temperature and stress at the laminate interface. The experimental results of cutting force, hole inlet and outlet surface morphology, inner wall condition, chips, tool wear, etc. under different machining parameters were studied and analyzed. To ensure the reliability of our findings, experimental data were validated against simulation results. The findings reveal that UAD, when optimal separation conditions are achieved, significantly reduces cutting forces and enhances the surface morphology of both the inner and outer hole surfaces. Specifically, UAD lowers cutting forces by 27.2 % and the damage coefficient (Fd) by 15.7 % compared to CD. Furthermore, the high-frequency vibration generated by UAD markedly extends tool life. The specially designed high-frequency vibration spindle successfully meets drilling requirements, thereby significantly improving the machining performance of CFRP/Ti stacks materials, and it provides a certain reference for practical industrial applications.

Evolutionary topology optimization with stress control for composite laminates using Tsai-Wu criterion

In this study, a topology optimization technique with stress control is proposed for the composite laminates. The bi-directional evolutionary structural optimization (BESO) method is selected to avoid the stress singularity. The technique expresses the failure index based on the Tsai-Wu criterion, thereby ensuring a comprehensive consideration of the anisotropy. To address the local nature of stress and multi-layer structure of laminates, a nested p-norm is employed, providing a global approximation of the local maximum failure index. To mitigate the highly non-linear stress behaviors, filter schemes are applied to both sensitivity numbers and design variables. Sensitivity numbers are derived via adjoint sensitivity analysis and Lagrange multipliers to address stress-based and stress-constrained problems. The proposed framework is validated through systematic numerical studies across various examples and conditions, offering insights into the topological behaviors of composite laminates. This study underscores the importance of considering distinct tensile and compressive strength in composite materials, which represents a key innovation. Additionally, the relationships among stiffness-based, stress-constrained, and stress-based designs are explored in depth.

Effect of Post-Heat Treatment on the Mechanical and Residual Stress Behavior of Pulsed Wave S316L Fabricated by Directed Energy Deposition.

The influence of annealing at various temperatures on the phase stability and microstructure of pulsed-wave laser mode (PW) 316L stainless steel fabricated via Directed Energy Deposition (DED) was systematically investigated. The microstructural alterations resulting from heat treatment were examined to clarify their influence on the mechanical properties of the specimens subjected to tensile loading. The results showed that cell size increased with annealing temperature, with the cellular microstructure disappearing at higher temperatures (T ≥ 1000 °C). A decrease in the mechanical strength of the specimens was observed as annealing temperature increased. Additionally, the influence of different laser pulse frequencies and duty cycles on residual stresses was examined, revealing that moderate laser frequencies and duty cycles effectively reduced residual stress levels.

Childhood Posttraumatic Stress and School-Related Behaviors: A Scoping Review

Childhood Posttraumatic Stress and School-Related Behaviors: A Scoping Review

Study on the Hydrodynamic Effects of Bridge Piers Under Velocity-Type Pulse Ground Motion Based on Different Characteristic Periods

This study was based on a target spectrum (GB183062015) and synthesized different characteristic periods, pulse ground motions, and non-pulse ground motions utilizing EQsignal v1.2.1 software. It also investigated the dynamic behaviors of bridge piers in seismic motions with varying characteristic periods, pulse and non-pulse effects, and the influence of 0 m and 10 m water depths. The findings indicated that the peak acceleration and stress behaviors vary significantly under different characteristic periods of ground motion. The maximum error in peak acceleration behavior of a bridge pier under ground motions of varying characteristic periods is 19.25%, while the maximum error in peak stress response is 11.35%. The acceleration and stress behaviors of a bridge pier under pulse ground motion action are more considerable than those under non-pulse seismic motion action. When the characteristic period is 0.40 s, the maximum error in peak acceleration of the bridge pier structure under pulse seismic motion and non-pulse seismic motion action is 86.08%, with the maximum error of the peak stress reaches 80.68%. The existence of water serves to minimize the natural frequency of the bridge pier. The pulse effects result in a maximum error of 40.49% for the peak acceleration and a maximum discrepancy of 323.08% for the peak stress of the bridge pier. The hydrodynamic effects result in a maximum error of 33.51% for the acceleration peak and 12.90% for the stress peak of the bridge pier. The effect of the pulse symptoms on the dynamic behavior of the bridge pier is considerably more pronounced than that of the hydrodynamic effects, with an intricate and complex influencing mechanism. In bridge flood protection and seismic design and optimization, it is essential to consider the impact of pulse seismic motion with varying characteristic periods.

Unraveling the Effects of Strain-Induced Defect Engineering on the Visible-Light-Driven Photodynamic Performance of Zn2SnO4 Nanoparticles Modified by Larger Barium Cations.

Waterborne infections caused by pathogenic microorganisms represent serious health risks for humans. Ternary zinc-tin oxide nanoparticles have great potential as a cost-effective, environmentally friendly, and efficient candidate for waterborne infections; however, their photocatalytic and antibacterial effects are quite limited due to insufficient visible light absorption and rapid electron-hole recombination. Herein, barium-doped zinc stannate (Ba@ZTO) nanoparticles were synthesized by the hydrothermal method and used for the first time not only as antibacterial agents to prevent the spread of the harmful bacteria S. aureus and E. coli but also as photocatalysts to degrade the organic pollutant rhodamine B. Unexpectedly, Ba2+ ions exhibited compressive stress behavior instead of the predicted tensile stress when inserted into the ZTO crystal lattice, playing an active role in increasing oxygen vacancies within the crystal lattice and in the formation of hydroxyl radicals in the bulk solution and hydrogen peroxide (H2O2) radicals, significantly improving the photocatalytic and antibacterial properties. Strain-induced defects created by the insertion of larger barium ions into the ZTO lattice promote the increase of shallow traps for boosting photocatalytic/disinfection properties while suppressing deep-level traps that encourage nonradiative recombination. In essence, defect and strain engineering opens a promising route to achieve high disinfection efficiency by inducing larger cation ions under visible light in oxide-based materials.

An Implicit Fillet‐Weld Element Formulation for Mesh‐Insensitive Fatigue Evaluation of Complex Structures

ABSTRACTIn fatigue evaluation of welded structures, explicit weld representations in finite element (FE) models are needed for reliably capturing stress or strain concentration behaviors at critical weld locations, for example, weld toe or weld root, in using widely accepted traction structural stress or extrapolation hot‐spot stress methods. The laborious efforts needed for generating weld geometry have been a major challenge for fatigue evaluation of complex structures containing many welds. In this paper, we present a user‐defined fillet‐weld element formulation and its numerical implementation for computing traction mesh‐insensitive structural stresses. The fillet‐weld element is formulated by connecting several linear four‐nodes Mindlin shell elements around weld region as a user‐defined element. The resulting elements can be directly used with major commercial FE codes through an available user subroutine interface. A number of well‐documented fillet‐welded components are then used for validating the accuracy and robustness of the developed fillet‐weld elements.

Personality and Psychoneuroimmunology: A Systems Biology Perspective.

Research in psychoneuroimmunology (PNI) underscores the intricate connections within the "whole mind-body system." Personality plays a pivotal role, with specific traits linked to stress influencing neural behavior and psychophysiological disorders. Gene expression networks associated with personality affect neuronal plasticity, epigenetic processes, and adaptive behaviors, highlighting the importance of systems biology mechanisms. Systemic inflammation correlates with key personality traits. Understanding the roles of inflammatory and oxidative biomarkers in personality traits and disorders can help identify diagnostic and therapeutic targets for various diseases. Neurobiological features contribute to our understanding of personality disorders and related conditions. Personality traits are linked to distributed neuroendocrine networks, particularly the hypothalamic-pituitary-adrenal (HPA) axis, rather than localized brain areas. Correlations have also been identified between personality traits and thyroid hormones. Disrupted hypothalamic-pituitary-thyroid (HPT) axis functions may be associated with disease severity, depression, and distress, highlighting the need for comprehensive endocrinological and psychopathological evaluations. The gut-brain axis influences personality traits, emotions, stress, and social behaviors. Altered gut microbiota is common in psychiatric conditions, suggesting potential treatments targeting the microbiota. Chronic stress impacts cognitive functions and correlates with personality and mental health, emphasizing the need for comprehensive, multi-dimensional patient profiles for effective prevention and therapy. A biopsychosocial model integrating personality traits will advance personalized and systems medicine.