Stress Difference Research Articles

The Effect of Five-Finger Relaxation Technique on Anxiety and Stress in Non-Hemorrhagic Stroke Patients at the Inpatient Installation of RSUD Cimacan Cianjur District

Aims: The purpose of this study was to examine the effect of five-finger relaxation technique on anxiety and stress in hemorrhagic stroke patients at Cimacan Hospital. Methods: This study used quasi-experiment with nonequivalent control group design. Sample collection using purposive sampling. The sample was 40 people and divided into two groups with 20 people each for the intervention group and control group. Data analysis using Paired Sample T-Test and Independent Sample T-Test. Results: The results showed that after the five-finger relaxation technique was performed on the intervention group, there was a decrease in anxiety levels (p = 0.000) and stress (p = 0.000) in stroke patients, while in the control group there was a decrease in anxiety (p = 0.000) and stress (p = 0.000), and there was a difference between anxiety levels (p = 0.000) and stress (p = 0.000) in the intervention and control groups. Conclusion: There is an effect of five-finger relaxation technique on anxiety and stress in non-hemorrhagic stroke patients, and there are differences in anxiety and stress in the control and intervention groups. It is hoped that this five-finger relaxation technique can be used as an evidence base nursing on non-pharmacological treatment as a form of independent nursing intervention by a nurse in providing nursing care to help in the process of reducing anxiety and stress in stroke patients.

A new layered rock constitutive model incorporating confining pressure and bedding angle weights based on orthogonal matrix analysis

Under the combined influences of confining pressure, lithology and bedding, the deformation and failure characteristics of layered rocks become more complex posing a significant challenge in safe underground excavations. In this study, two groups of specimens were prepared with various bedding angles including 0°, 10°, 20°, 30°, and 45°. X-ray diffraction and scanning electron microscopy were employed to analyze the mineral composition and internal microstructures of the specimens. Triaxial compression tests were conducted on the specimens subject to different confining pressures. Then, orthogonal matrix analysis was utilized to determine the specific influence weights of confining pressure, lithology, and bedding on peak differential stress, elastic modulus and peak strain of the rock samples. Finally, by implementing the proposed weight matrix, a statistical damage constitutive model for the layered rock under the coupled effects of confining pressure, lithology, and bedding was developed. It was found that the peak stress difference, cohesion, and internal friction angle decrease as the bedding angle increases, while the elastic modulus increases with the bedding angle. Additionally, the two groups of specimens exhibited distinct failure patterns under the influence of bedding angle and confining pressure. The averaged influence weights of confining pressure, lithology, and bedding on the rock deformation and failure characteristics are 40.99%, 23.87%, and 35.14%, respectively. The analytical simulation results were validated with the experimental results in this study and literature confirming the capability of the proposed constitutive model for capturing the stress–strain behavior of layered rock with various bedding angles subject to different confining pressures.

A Dynamic Propagation Numerical Model of Hydraulic Fracture Interactions with Pre-Existing Complex Natural Fractures

The propagation of hydraulic fractures is highly influenced by the geological structure of the reservoir in unconventional reservoirs, such as natural fractures. In this paper, a new fluid–solid coupling dynamic model was built which presents the failure mechanism of hydraulic fracture with pre-existing simple and complex natural fractures. The cohesive element method and the maximum principal stress fracture criterion were used in the new model. An analysis was conducted to investigate the impact of various factors, including encounter angle, in situ stress, elastic modulus, and Poisson’s ratio, on the propagation of hydraulic fractures. The simulation results indicate that the encounter angle and the in situ stress are the main factors affecting the fracture morphology. When the encounter angle and the in situ stress difference are small, hydraulic fractures propagate along natural fractures. When the elastic modulus is small, it is advantageous for the advancement of both hydraulic and natural fractures. The Poisson’s ratio has a slight effect on the fracture propagation pattern.

The effect of resilience training with mHealth application based on micro-learning method on the stress and anxiety of nurses working in intensive care units: a randomized controlled trial

IntroductionNurses in intensive care units (ICUs) face high stress and anxiety, impacting their well-being and productivity. Addressing this, this study evaluated the impact of resilience training via a mHealth application based on micro-learning on ICU nurses’ stress and anxiety levels.Materials and methodsThis study, a single-blind randomized controlled trial conducted in 2022-23, involved sixty ICU nurses from two Tehran hospitals. Nurses were chosen through purposive sampling and divided into intervention and control groups by simple randomization. The intervention group was taught resilience via an educational mHealth application based on micro-learning, with data collected using the anxiety and stress subscales of DASS-21.ResultsBefore the intervention, there were no significant differences in stress and anxiety scores between the intervention and control groups (P > 0.05). Upon utilizing the mHealth application, the intervention group exhibited significant reductions in stress, from 10.77 ± 3.33 to 9.00 ± 1.66 (P = 0.001), and in anxiety, from 9.43 ± 3.35 to 7.93 ± 0.98 (P < 0.001). In contrast, the control group experienced a slight increase in stress levels, from 10.10 ± 2.19 to 10.73 ± 2.15 (P = 0.002), and in anxiety levels, from 9.10 ± 1.63 to 10.23 ± 1.65 (P < 0.0001).ConclusionsThe micro-learning-based mHealth application for resilience training significantly reduced ICU nurses’ stress and anxiety, recommending its adoption as an innovative educational method.Trial registrationThe study has been registered in the Iranian Registry of Clinical Trials (No. IRCT20221225056916N1, Date: 04/29/2023).

Brief online acceptance and commitment therapy for adults with type 1 diabetes: a pilot study.

Recognizing the pivotal role of psychosocial factors in triggering and maintaining Type 1 Diabetes Mellitus (T1DM), the integration of psychoeducational and psychotherapeutic interventions is associated with comprehensive management of the disease. This study aimed to evaluate the impact of a four-week online individual Acceptance and Commitment Therapy (ACT) intervention in mitigating diabetes-associated stress, fostering diabetes acceptance, enhancing the patient-doctor relationship, and promoting psychological flexibility in adults diagnosed with T1DM. Employing a single-arm trial design with mixed methodology, thirteen participants (Mage = 39.04, SDage =13.74) engaged in the intervention and completed self-report measures before and after the intervention. Quantitative analysis with the Wilcoxon signed-rank test indicated a statistically significant difference in diabetes-associated stress, diabetes acceptance, and psychological flexibility pre- and post-intervention. Notably, stress levels and psychological inflexibility diminished, while psychological flexibility and diabetes acceptance improved. However, the patient-doctor relationship did not exhibit a significant change. Furthermore, narrative feedback obtained from participants reflected overall satisfaction with the intervention. These preliminary findings contribute to the expanding body of literature supporting the affirmative influence of ACT interventions on individuals with T1DM.

Modeling of the thermal cooling of a glass plate on a metallic frame including radiation effects

Achieving a correct cooling in glass manufacturing is very important to obtain the desired level of stresses and to avoid breakage. Numerical simulations can be used to optimize the cooling parameters. Such simulations have to be multiphysical coupling thermics and mechanics. Moreover, since glass is a semitransparent material, radiative effects inside the glass have to be taken into account. The present paper is devoted to numerical study of the cooling of a glass square plate on a metallic frame. To this end, the commercial software Abaqus was used to model the thermomechanical behavior of glass using adapted subroutines and was combined with an in-house C++ tool developed to solve the Radiative Transfer Equation. During and at the end of the cooling, weak areas in the glass plate are revealed by the simulation. Depending on the case studied, taking accurately the radiative effects into account leads to difference of residual stresses which can reach 10 MPa in certain cases.

Numerical simulation of rock blasting under different in-situ stresses and joint conditions.

High primary rock stress can limit the generation of rock cracks caused by blasting, and blasting usually shows different rock breaking states under different primary rock stress conditions. There are a large number of naturally formed joints in rock mass, due to the limitations of laboratory tests, a numerical model of jointed rock mass was established using LS-DYNA software to investigate the evolution of blasting damage under various in-situ stresses and open joints. In this simulation, using the Lagrange-Euler (ALE) procedure and the equation of state (JWL) that defines explosive materials, the study considered different joint thicknesses (2cm, 4cm, and 6cm), joint angles (0°, 30°, 60°, and 90°), and in-situ stress conditions (lateral stress coefficients of 0.5, 1, and 2, with vertical in-situ stresses of 10MPa and 20MPa), through stress analysis and damage area comparison, the relationship between damage crack propagation and horizontal and vertical stress difference is explored. The research aimed to understand the mechanisms underlying crack initiation and propagation. The results show that: (1) The presence of joints exerts a barrier effect on the expansion and penetration of cracks. When explosion stress waves reach the joint surface, their propagation is impeded, leading to the diffusion of wing cracks at the joint ends. When the lateral stress coefficient and joint angle are the same, an increase in initial in-situ stress results in a reduction in the area of the blasting damage zone. (2) Under the same initial in-situ stress conditions, the area of the blasting damage zone initially increases and then decreases with an increasing joint angle. However, it remains larger than that without a joint, and there exists an optimal angle that maximizes the damage area. In the simulated conditions, the area of damage cracks is greatest when the joint angle is 60° dip angle. (3) The presence of initial in-situ stress has a certain impact on the initiation and expansion of blasting cracks. The degree and nature of this influence are not solely related to the lateral stress coefficient but also depend on the joint's angle and thickness. When in-situ stress is present, the initial in-situ stress field's pressure is not conducive to the initiation and propagation of blasting cracks. However, the existence of a joint has a noticeable guiding and promoting effect on crack propagation, and the pattern of crack propagation is influenced by both joint and in-situ stress conditions.

Optimising the steering clutch of a walking tractor using soft computing approaches

ABSTRACT Walking tractors are often used for weeding gardens, small fields, vineyards, and greenhouses. The clutch fork arm (CFA), which is used on the rotary axle, is subject to high loads. Therefore, an optimal design must be carried out under all load conditions while minimising weight. The present study aims to reduce the mass and load acting on the CFA and increase its safety factor. To achieve an optimal design, this study used the dimensions of the CFA as independent variables and the mass and maximum load exerted on the CFA as dependent variables. Multi-linear regression (MLR) and Artificial Neural Network (ANN) models were then developed. MLR and ANN models were proposed to predict the mass and load acting on the CFA. The proposed models were trained and validated using a dataset containing dimensions, mass parameters and maximum stresses for eighty-one CFA specimens based on the results of the finite element method (FEM). Based on the optimised structural properties, a FEM model of the CFA was then developed in Ansys R19.2. The results showed that the maximum absolute difference in stresses from the FEM and ANN models was less than 3.7%, while for mass it was less than 2.2%. Furthermore, the maximum reduction in mass and increase in safety factor were achieved by 52.0% (from 1.3 kg to 0.62 kg) and 36.0% (from 1.28 to 1.64), respectively. Therefore, these results were a confirmation of the ANN model to use as an alternative to the FEM method.

Torsional progressive damage mechanisms in 3-D braided carbon fiber/epoxy resin composite tubes

3-D braided composites are a promising material for manufacturing tubular structures. However, a thorough understanding of their damage mechanisms under torsion is required to maximize their potential applications. The present work constructed a multiscale equivalent model, integrating mesoscopic and homogeneous structures to reveal torsional behavior of 3-D braided carbon fiber/epoxy resin composite tubes. The cumulative failure process, spatial stress distribution and interface damage were calculated to illustrate stress transfer and damage initiation and propagation. It is found that stress varies on the surface and internally within the representative unit cell (RUC). The yarns experience both axial tension parallel to the direction of torsion and axial compression perpendicular to the direction of torsion. The stress difference between them leads to damage initiation and propagation. Interfacial cracking as main damage mode hinders the stress transfer between resin and fiber bundles. The results show that the braided yarn path, axial stress dispersion in two directions and localization of damage effectively impede the torsional damage propagation.

Stress and Coping in Patients With Cancer With Depression and Sleep Disturbance.

To evaluate for differences in global, cancer-specific, and cumulative life stress, as well as resilience and use of various coping strategies among five groups (no depression or sleep disturbance, no depression and moderate sleep disturbance, subsyndromal depression and very high sleep disturbance, moderate depression and moderate sleep disturbance [Both Moderate]; and high depression and very high sleep disturbance [Both High]). Patients (N = 1,331) receiving chemotherapy were recruited from outpatient oncology clinics. Measures of global, cancer-specific, and cumulative life stress, resilience, and coping were obtained. Differences were evaluated using parametric and nonparametric tests. Global and cancer-specific stress scores increased as joint profiles worsened. Both Moderate and Both High classes had cancer-specific stress scores suggestive of post-traumatic stress. Both Moderate and Both High classes reported higher occurrence rates for several stressful life events and higher use of disengagement coping. Both Moderate and Both High classes had resilience scores below the normative score for the United States. Clinicians need to screen vulnerable patients for post-traumatic stress disorder and implement interventions to reduce stress.

Investigation of the Mechanical Features of Steel–Concrete Composite Girder Rigid Frame Bridges with V-Shaped Piers during Construction Stages

Steel–concrete composite girder rigid frame bridges with V-shaped piers are a new type of bridge structure. Based on the traditional composite continuous beam bridge, part or all of the vertical piers are changed into V-shaped piers. This special structure makes them have the mechanical characteristics of both composite continuous beams and V-shaped piers. In this paper, the finite element model of the first steel–concrete composite continuous beam V-pier rigid frame bridge in China is established by simulation software, the construction process of the bridge is simulated, and the stress and deflection of the bridge in each construction stage are studied. At the same time, the stress of the completed bridge model considering the construction stage is compared with that of the completed bridge model without considering the construction stage. It is found that the stress difference between the two concrete slabs is as high as 2.7 MPa. The results show that the stress state of the bridge is greatly affected by the construction process. This study can provide guidance for the design and construction of such bridges, which is of great significance.

Effects of Geo-Stress and Natural Fracture Strength on Hydraulic Fracture Propagation in a Deep Fractured Tight Sandstone Reservoir.

Hydraulic fracturing technology has been widely used in the tight reservoir reconstruction. Unfortunately, with the deepening of mining depth and the increase of geo-stress, the propagation mechanism of medium-pressure fractures in the reservoir is significantly different from that of conventional shallow reservoirs. Based on the combined finite discrete element method, this paper conducts numerical simulation research on deep tight sandstone reservoirs in the west. The discrete fracture network modeling method is used to establish a tight sandstone reservoir model with natural bedding, and the influence of geo-stress difference and natural fracture strength on hydraulic fracture propagation law in a high geo-stress environment is discussed in detail. The results show that the difference between geo-stress and the strength of natural fractures has a significant effect on the shape and expansion of hydraulic fractures under the high geo-stress conditions. The greater the difference in ground stress, the more obvious the tendency of the main fractures of the reservoir, and the shorter the branch fractures. With the increase of natural fracture strength, the changes in propagation pressure, fracture length, area, and width, which can be fitted with a linear function with a goodness of fit as high as 0.99. In addition, the morphological results of hydraulic fractures in the simulation are not only affected by the constitutive parameters of the model but also may be affected by the randomness of the natural fracture network, thus, showing a certain degree of dispersion. Therefore, it is extremely necessary to build a reservoir fracturing model in a specific area based on more detailed geological monitoring data to guide actual construction. The above achievements have certain reference significance for the field operation of deep tight sandstone reservoirs.

New insights into the effects of low temperatures on the stress-optical properties of printable photopolymers: An experimental investigation

The application of 3D printing technology for replicating natural rock models and achieving the visualization and quantification of hidden structural changes and stress evolution in underground rocks holds significant importance for engineering disaster prevention as well as the development of oil and gas resources. The key to achieving this lies in developing model materials suitable for 3D printing that accurately depict the physical and mechanical properties of rocks. In this paper, the impact of temperature cycle treatment on the mechanical properties of printing material VeroClear was tested and the effect of temperature on the stress-optical properties of VeroClear was analyzed. By using 3D printing models with pre-existing cracks, the crack initiation conditions, propagation laws and stress field distribution characteristics of stress-sensitive materials at different temperatures were obtained. The results show that the mechanical properties of the freshly printed VeroClear model exhibit instability due to incomplete curing. Heat treatment can facilitate complete curing and enhance their mechanical characteristics, whereas cold treatment fails to yield similar improvements. Lower ambient temperatures reduce photoelastic fringe susceptibility to stress, yet allow accurate quantification of full-field stress within models by VeroClear. Lowering the temperature significantly enhances the brittleness of VeroClear, enabling printed models to demonstrate crack evolution characteristics similar to those observed in actual rocks. By analyzing the evolution of photoelastic fringe, it is found that the wing crack propagates along the direction of the local minimum principal stress difference near the crack tip. These findings provide a foundation for utilizing stress-sensitive materials with enhanced brittleness in low-temperature environments for simulating rocks and quantitatively analyzing their fracture behavior and the role of stress field control.

Mechanism for axial pattern formation of concentrated suspension in a horizontal rotating cylinder

We have performed numerical simulations to investigate the phenomenon of axial pattern formation exhibited by a non-neutrally buoyant concentrated suspension. Continuum modelling of the concentrated suspension is done using the suspension balance model to identify the underlying mechanism of the phenomenon. We demonstrate that axial concentration variations become amplified to axial bands owing to the influence of the second normal stress difference ( $N_2$ ), and the first normal difference ( $N_1$ ) accentuates the effect of $N_2$ . We demonstrate that the end walls of the rotating cylinder are necessary to prevent the smearing out of axial bands but are not a direct cause of the phenomenon.

Simulation and Control Strategies for Longitudinal Propagation of Acid Fracture in a Low-Permeability Reservoir Containing Bottom Water

The reservoir in the Anyue gas field, located in the Sichuan basin of China, belongs to the second member of the Dengying formation and has distinctive geological features. It is characterized by strong heterogeneity, low porosity, low permeability, and locally developed natural fractures. The reservoir space consists primarily of corrosion holes, natural fractures, and similar voids. Moreover, the lower reservoir exhibits high water saturation and a homogeneous bottom-water interface. Since it is a carbonate-based hydrocarbon reservoir with low porosity and permeability, deep acid fracturing has proven to be an efficient method for enhancing individual well production. However, the reconstruction of the second member of the Dengying formation reservoir poses significant challenges. The reservoir contains high-angle natural fractures, small vertical stress differences, and is located in close proximity to the gas–water interface. As a result, it becomes difficult to control the height of the acid break. Improper acid break treatment may easily result in water production affecting gas well production. To explore ways to control the longitudinal extension of acid fractures, 3D numerical models focusing on the initiation and expansion of acid fractures have been developed. This model takes into account geological and engineering factors such as stress differences, acid fracture displacements and scales, and their effects on the longitudinal extension of acid fractures. It was revealed that the pressure difference is the main controlling factor for the acid fracture height, followed by the reservoir thickness, the interlayer thickness, and the viscosity of the working fluid. Technical countermeasures for controlled fracture and high-acid fracturing tailored to different reservoir characteristics have been proposed, and design parameters for controlled fracture and high-acid fracturing can be optimized. By effectively controlling the vertical extension of the acid fracture, it is possible to maximize production from a single well while avoiding interference from the lower water layer. This study provides theoretical guidance for the application of deep-acid-fracturing techniques in low-permeability bottom-water gas reservoirs.

Propagation and complex morphology of hydraulic fractures in lamellar shales based on finite-discrete element modeling

We explore the controls of stress magnitude and orientation relative to bedding on the resulting morphology/topology of hydraulic fractures using a combined finite-discrete element method (FDEM). Behavior is shown conditioned by the ratio of principal stresses λ=σ3/σ1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\lambda ={\\sigma }_{3}/{\\sigma }_{1}$$\\end{document} and relative inclination of the bedding. When the lateral pressure coefficient (λ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\lambda$$\\end{document}) is less than 0.67, hydraulic fractures predominantly initiate as tensile fractures along the wellbore, aligning with the maximum principal stress direction. Conversely, for λ≥0.67\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\lambda \\ge 0.67$$\\end{document}, shear cracks are favored to initiate for the minor stress difference, leading to a less predictable initiation and extension direction. Simultaneously, diminished stress differences correspond to elevated reservoir breakdown pressures, displaying a linear correlation with lateral pressure coefficients and little influenced by equivalent bedding orientation. Bedding plane orientation significantly impacts the mode and morphology of hydraulic fracture propagation. Bedding parallel to the direction of the minimum principal stress (σ3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\sigma }_{3}$$\\end{document}) favors layer-penetrating and bifurcated fractures, whereas inclined bedding facilitates the emergence of numerous steering-type and capture-type fractures. Especially at steeper inclinations (β=60∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta =60^\\circ$$\\end{document}), hydraulic fractures readily extend along the bedding surface, inducing macroscopic shear slip failure. Under high-stress disparities, the breakdown pressure exhibits greater sensitivity to bedding inclination, and its influence pattern aligns with the variations in tensile strength, typically reaching maximum and minimum values at bedding inclination angles of 0° and 60°, respectively.

Tectonic fractures induced by strike-slip faulting in intracratonic ultradeep carbonate rocks: Insights from the finite element method and self-adaptive constraints computational model for boundary conditions

Numerical simulations of the paleostress field during a period of tectonic fracture formation and rock failure criteria are used to quantitatively predict the development and occurrence of tectonic fractures induced by the formation of the SB18 fault zone in the Middle Ordovician Yijianfang Formation of the Shunnan area, Tarim Basin, China. The results of acoustic emission experiments, mechanical property measurements, and tectonic fracture occurrence observations obtained from core descriptions and fullbore formation microimager logs are combined with the Andersonian model of faulting and the finite element method, which is widely used for the numerical simulation of stress fields, to investigate the paleotectonic and in situ stress fields via numerical simulation. The quantitative prediction of the opening pressure and opening sequence of tectonic fractures is based on the occurrence of tectonic fracture, numerical simulation of in situ stresses, and coordinate system conversion. The results show that the width of the fracture zone induced by strike-slip faulting is ∼310 m. The degree of fracture development is significantly increased when the Young’s modulus, paleostress difference, and paleostress difference coefficient of the rock are elevated. The current horizontal principal stress is positively correlated with the distance from the fault, and the elevated areal density of the secondary faults causes a clockwise deflection of the horizontal stress direction. SSE-striking shear fractures with orientations ranging from 140° to 150° and two sets of tensional fractures with orientations ranging from −40° to −35° and 55° to 60° are preferentially opened in the water injection development stage of the reservoir. As the horizontal stress difference, horizontal stress difference coefficient, and angle between the maximum horizontal principal stress and a fracture decrease, the fracture opening pressure decreases. At the structural highs (burial depths &amp;lt;6225 m) and lows (burial depths &amp;gt;6225 m), the fracture burial depth is positively and negatively correlated with the opening pressure, respectively. Quantitative prediction of tectonic fracture developmental characteristics, opening pressure, and the opening sequence and investigation of the main factors that control their development can help to identify and support opportunities for hydrocarbon exploration and development of fractured carbonate reservoirs.

Influence of circle of Willis modeling on hemodynamic parameters in anterior communicating artery aneurysms and recommendations for model selection

Computational fluid dynamics (CFD) has been utilized to calculate hemodynamic parameters in anterior communicating artery aneurysm (AComA), which is located at a junction between left and right A1 and A2 segments. However, complete or half circle of Willis (CoW) models are used indiscriminately. This study aims to suggest recommendations for determining suitable CoW model. Five patient-specific CoW models with AComA were used, and each model was divided into complete, left-half, and right-half models. After validating the CFD using a flow experiment, the hemodynamic parameters and flow patterns in five AComAs were compared. In four out of five cases, inflow from one A1 side had a dominant influence on the AComA, while both left and right A1 sides affected the AComA in the remaining case. Also, the average difference in time-averaged wall shear stress between the complete and half models for four cases was 4.6%, but it was 62% in the other case. The differences in the vascular resistances of left and right A1 and A2 segments greatly influenced the flow patterns in the AComA. These results may help to enhance clinicians’ understanding of blood flow in the brain, leading to improvements in diagnosis and treatment of cerebral aneurysms.

The relationship between gender, psychosocial factors, pain, health literacy and health-related quality of life in parents of Norwegian adolescents one year into the COVID-19 pandemic

BackgroundStress impacts healthy behaviours and may influence life and health-related quality of life (HRQOL). A stressful event occurred when the COVID-19 pandemic hit in March 2020. The present study aims to explore possible gender differences in stress, psychosocial factors (self-efficacy, self-esteem, loneliness), pain, HL, and HRQOL in parents of adolescents one year into the COVID-19 pandemic, and to explore possible associations between gender, demographic and psychosocial factors, pain, HL, and HRQOL.MethodsParents of adolescents aged 16–17 took part in the study from January to February 2021, when the COVID-19 pandemic was ongoing. Data on socio-demographics, stress, self-efficacy, self-esteem, pain, HL, loneliness, and HRQOL were collected. HRQOL was assessed using RAND-36.ResultsAmong the 320 parents from the general population, the mean age was 47.6 (standard deviation (SD) = 4.6) years, 81% were mothers, 79% were married or cohabiting, 81% had a university degree, and the majority worked full time (78%) or part time (13%). The average pain score was low, 0.48 (95% CI [0.43–0.54]). However, 50% of the parents reported persistent pain and more mothers reported persistent pain compared to fathers (53% vs. 37%). The parents’ mean (SD) score for RAND-36 was 52.1 (95% CI [51.2–53.0]) for the physical component summary (PCS) score and 51.0 (95% CI [50.0–52.1]) for the mental component summary (MCS) score. Mothers reported significantly lower scores for all the eight RAND-36 domains and the PCS and MCS scores. Adjusting for gender, age, living condition, education, pain, HL, self-efficacy and loneliness, we revealed no associations between stress and RAND-36-PCS. University education of four years or more was positively associated (B = 3.29, 95% CI: [0.78–5.80]) with RAND-36-PCS, while persistent pain was negatively associated (B = -7.13, CI: [-9.20– -5.06]). We identified a strong negative association between RAND-36-MCS and stress (B = -43.11, CI: [-48.83– -37.38]) and a positive association with older age (B = 0.21, CI: [ 0.04, 0.39)].ConclusionOne year into the COVID-19 pandemic, we identified a strong negative association between stress and mental HRQOL, while pain was strongly negatively associated with physical HRQOL.

Numerical Simulation of Fracture Propagation during Temporary Plugging Staged Fracturing in Tight-Oil Horizontal Wells.

Fracture propagation with temporary plugging hydraulic fracturing in tight-oil reservoirs is simulated in this study. The research considers dynamic fluid redistribution, with stress differences among multiple fractures. The fracture morphology during temporary plugging staged fracturing (TPSF) is investigated by using a user-defined perforation element combined with a pore-pressure finite-element model. The precision of the integrated model is verified by using the standard finite-element approach. Then, case studies are presented to investigate the influence of cluster spacing, horizontal stress difference coefficients (SDC), injection rates, and barrier tensile strengths. The simulation results show that central cluster fractures are hampered by side-cluster fractures, while TPSF can alleviate the effect and lead to a more uniform propagation of all fractures. Stress interference weakens as cluster spacing increases, and propagation patterns are minimally influenced once spacing reaches 40 m. Higher injection rates can improve the injection pressure, enlarging fracture width, and potentially increasing the risk of fracture penetration. Barrier tensile strength and horizontal SDC can modify fracture geometries and determine the penetration behavior of multiple fractures.