Effects of Barrier Stiffness on Debris Flow Dynamic Impact—I: Laboratory Flume Test

Debris flows often cause local damage to engineering structures by exerting destructive impact forces. The debris-flow–deformable-barrier interaction is a significant issue in engineering design. In this study, a large physical flume model test device was independently designed to repeatedly reproduce the flow and impact process of debris flow. Three physical flume tests were performed to investigate the effect of barrier stiffness on the debris flow impact. The flow kinematics of debris flow with three barrier stiffness values are essentially consistent with the process of impact–run-up–falling–pile-up. The development of a dead zone provided a cushion to diminish the impact of the follow-up debris flow on the barrier. The peak impact forces were attenuated as the barrier stiffness decreased. The slight deflections of a deformable barrier were sufficiently effective for peak load attenuation by up to 30%. It showed that the decrease of the barrier stiffness had a buffer effect on the debris flow impact and attenuated the peak impact force. And with the decrease of the barrier stiffness, when the barrier was impacted by the same soil types, the recoverable elastic strain will be larger, and the strain peak will be more obvious.

The Buffer Effect

The mediating nature of communication technologies (e.g., telephone, voice message, or chat) can buffer the experience of conversations by establishing a figurative shield between sender and receiver. From a psychological perspective, this buffer effect may affect senders’ communication channel choices depending on their respective communication goals. Building on the impression management model of strategic channel use ( O’Sullivan, 2000 ), we examine how valence and locus of a message and the interlocutors’ relationship lead to differences in the buffer effect people establish through their channel choices. In two vignette-based, mixed-design studies, participants indicated which channel they would choose to communicate with a receiver in different situations, depending on the valence of the episode (positive vs. negative; Studies 1 and 2), who is at the center of the issue (self vs. other; Studies 1 and 2), and their interpersonal closeness (friend vs. acquaintance; Study 2). In Study 1, people chose channels with a higher buffer effect for negative (vs. positive) issues and episodes that focused on themselves (vs. the receiver). Study 2 supported a moderating effect of relationship. While people still chose channels with higher buffer effects for negative (vs. positive) issues in the acquaintance condition, the opposite was true when people were to communicate with friends. We attribute this to the higher salience of relational compared to self-presentational communication goals under increasing interpersonal closeness. The present studies expand the impression management model by focusing on the subjective buffer effect of communication channels and introducing the decisive role of relationship in its application.

Effect of pH and Al Cations on Chromate Inhibition of Galvanic-Induced Corrosion of AA7050-T7451 Macro-Coupled to 316SS

The performance of chromate in protecting AA7050-T7451 coupled to 316SS in simulated fastener environments, including those representative of the boldly exposed surfaces and downhole conditions, was investigated utilizing a number of electrochemical and surface characterization techniques. The influence of pH and Al3+ on the galvanic coupling behavior and damage evolution on AA7050 as a function of chromate concentration were assessed. The degree of chromate inhibition was observed to decrease as pH decreased, owing to chromate speciation and reduced capacity to suppress the hydrogen evolution reaction (HER) compared to the oxygen reduction reaction (ORR). The addition of 0.1 M Al3+ significantly increased HER kinetics and produced a large buffer effect which overwhelmed the ability of chromate to slow damage propagation on AA7050. Assessment of cathodes indicated that Cu was more important than 316SS in driving damage initiation, but less active than 316SS in supporting high-rate damage propagation in simulated crevice environments. The implications of this study for actual bimetallic systems are discussed.

Stress Impact of COVID-19 Sports Restrictions on Disabled Athletes

The stress impact of COVID-19 restrictions has put the adapted sports community at an unprecedented level of emergency. The self-report Event Scale—Revised (IES-R) questionnaire was administered to assess the level of psychological distress and emotive reactions such as intrusion (INT), avoidance (AV) and hyperarousal (HYP) following training and competitions suspension within a sample of Italian disabled athletes. A total of 146 self-selected volunteers were included in this study: 73 disabled athletes (aged 42.11 ± 13.70) and 73 athletes (aged 40.23 ± 13.73) who served as the control group. Only 8.22% of the disabled participants vs. 30.14% of athletes were affected by subjective distress. MANOVA showed significant differences in IES-R subjective distress for age, where the emerging adults had a higher level of stress than adults (p = 0.031), and for the type of sport, where the individual sports group showed higher scores than the team sports group (p = 0.049). Regarding the IES-R subscales, significant differences were found in INT and AV for age, where the emerging adults showed higher scores than adults (p = 0.018 and p = 0.046, respectively). Significant differences were found in HYP for type of sport, where the individual sports group showed higher scores than the team sports group (p = 0.014). The results confirmed a lower distress level of disabled athletes to adverse events than that expressed by athletes. Both sports engagement and the experience of living with impairment, overcoming structural barriers, could act as a buffer effect against stress due to COVID-19 restrictions.

Impact Resistance Analysis and Optimization of Variant Truss Beam Structure Based on Material Properties

In order to meet the increasing application requirements with regards to structural impact resistance in industries such as mining, construction, aerospace engineering, and disaster relief and mitigation, this paper designs a variant truss beam structure with a large shrinkage ratio and high impact resistance. Based on the principle of the curved trajectory of scissor mechanisms, this paper conducts a finite element simulation analysis of the impact load on the truss beam structure, a theoretical analysis of the impact response and a relevant prototype bench-top experiment, completing a full study on the impact resistance mechanism of the designed variant truss beam structure under the impact load. In the paper, the buffer effect of the external load impact on the variant truss beam structure is analyzed from the perspective of the energy change of elastic–plastic deformation. This paper proposes an optimization strategy for the variant truss beam structure with the energy absorption rate as the optimization index through extensive analysis of the parameter response surfaces. The strategy integrates analyses on the response characteristic analysis of various configuration materials to obtain an optimal combination of component parameters that ensures that the strength of the truss beam structure meets set requirements. The strategy provides a feasible method with which to verify the effectiveness and impact resistance of a variant truss structure design.

The Influence of Parental Rejection Style on Children’s Depression: The Moderating Role of Teacher Support

The purpose of this study was to explore the relationship between parental rejection and childhood depression and the moderating role of teacher support in this relationship. EMBU-C, CES-D10, PSSS and other tools were used to measure parental rearing style, children’s depression mood and perceptive teacher support. The results showed that parental rejection style was positively correlated with children’s depression, and teacher support was negatively correlated with children’s depression. Teacher support acted as a buffer effect between parental rejection and children’s depression.

Does Slack Buffer? Market Performance after Environmental Shock

Slack is a resource held by a firm but exceeds its needs. It is crucial for a firm to raise more attention on slack when facing environmental shocks, which are one of the causes of unsustainability. Based on agency theory and behavioral theory, this paper analyzes the buffer effect of slack on market performance under different periods and degrees of environmental shocks. Taking two major earthquakes that occurred in China as the natural experimental background and the listed firms in hit areas as the sample, we find that environmental shock is exposed to acts as a positive contingency for the impact of unabsorbed slack on market performance, and as a negative contingency for absorbed slack’s effect. The severity of environmental shock promotes the unabsorbed slack to act as a buffer in the immediate post-shock period and absorbed slack in the during-shock period. These findings contribute to answering the question of how to configure slack to protect firms and even achieve sustainable development when facing environmental shock.

Pandora's Box

If you have started feeling your age or even older, stop right there! Feeling younger makes us feel better and healthier both physically and mentally; at least so say researchers from Germany. They examined longitudinal data collected over a period of three years (2014–2017) by the German Ageing Survey, with a mean age of 64 years (40–95). Controlling for baseline functional health and sociodemographic variables, they found that greater perceived stress was associated with a steeper decline in functional health, which increased with advancing chronological age. However, they also found that those who felt younger than their age showed a less steep decline in functional health and greater perceived stress was less strongly associated with functional health decline. Furthermore, they were less likely to feel stressed and this stress buffer effect was greater with increasing age.