Stress Effect on Attention Level Detection Using Neurosky Mindwave Headset

ObjectiveTo evaluate the level of worry and its influencing factors during the COVID-19 epidemic among teachers in Henan Province in China.Study designA cross-sectional study was conducted.MethodsWe designed a cross-sectional survey that included 88 611 teachers from three cities in Henan Province, China between 4 February 2020 and 12 February 2020. Level of worry was measured using a five-item Likert scale, with 1 being ‘not worried’ and 5 being ‘very worried’. The OR and 95% CI of potential influencing factors for level of worry among study participants were estimated using ordinal logistic regression models.ResultsAbout 59% of teachers reported being ‘very worried’ about the COVID-19 epidemic. The proportion of female teachers was higher than of male teachers (60.33% vs 52.89%). In all age groups considered in this study, a ‘very worried’ condition accounted for the highest proportion. The age group 40–49 years had the lowest proportion of participants who were very worried, 52.34% of whom were men and 58.62% were women. After controlling for potential confounding factors, age, education level, type of teacher, school location, attention level, fear level, anxiety level and behaviour status were all related to level of worry (all p<0.05).ConclusionDuring the COVID-19 epidemic, there was a high proportion of teachers who were ‘very worried’ about the situation in Henan Province, China. Our study may remind policymakers to consider factors including age, educational status, type of teacher, school location, source of information on COVID-19, attention level, anxiety level, fear level and behaviour status to alleviate worry.

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The Effect of Wall Shear Stress on Two Phase Fluctuating Flow of Dusty Fluids by Using Light Hill Technique

Water ◽

10.3390/w13111587 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1587

Author(s):

Dolat Khan ◽

Ata ur Rahman ◽

Gohar Ali ◽

Poom Kumam ◽

Attapol Kaewkhao ◽

...

Keyword(s):

Shear Stress ◽

Wall Shear Stress ◽

Base Fluid ◽

Perturbation Technique ◽

Fluid Velocity ◽

Dust Particles ◽

Stress Effect ◽

Parallel Plates ◽

Dusty Fluid ◽

Wall Shear

Due to the importance of wall shear stress effect and dust fluid in daily life fluid problems. This paper aims to discover the influence of wall shear stress on dust fluids of fluctuating flow. The flow is considered between two parallel plates that are non-conducting. Due to the transformation of heat, the fluid flow is generated. We consider every dust particle having spherical uniformly disperse in the base fluid. The perturb solution is obtained by applying the Poincare-Lighthill perturbation technique (PLPT). The fluid velocity and shear stress are discussed for the different parameters like Grashof number, magnetic parameter, radiation parameter, and dusty fluid parameter. Graphical results for fluid and dust particles are plotted through Mathcad-15. The behavior of base fluid and dusty fluid is matching for different embedded parameters.

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Mechanism of Nano-Structuring Manipulation of the Crystallization Temperature of Superlattice-like [Ge8Sb92/Ge]3 Phase-Change Films

Nanomaterials ◽

10.3390/nano11010020 ◽

2020 ◽

Vol 11 (1) ◽

pp. 20

Author(s):

Qingqian Qiu ◽

Pengzhi Wu ◽

Yifeng Hu ◽

Jiwei Zhai ◽

Tianshu Lai

Keyword(s):

Phase Change ◽

Crystallization Temperature ◽

Lattice Mismatch ◽

Stress Effect ◽

Phonon Modes ◽

Cycle Number ◽

Interfacial Effects ◽

Compressive Stresses ◽

Crystalline Films ◽

Change Material

Superlattice-like (SLL) phase-change film is considered to be a promising phase-change material because it provides more controllabilities for the optimization of multiple performances of phase-change films. However, the mechanism by which SLL structure affects the properties of phase-change films is not well-understood. Here, four SLL phase-change films [Ge8Sb92(15 nm)/Ge (x nm)]3 with different x are fabricated. Their behaviors of crystallization are investigated by measuring sheet resistance and coherent phonon spectroscopy, which show that the crystallization temperature (TC) of these films increases anomalously with x, rather than decreases as the interfacial effects model predicted. A new stress effect is proposed to explain the anomalous increase in TC with x. Raman spectroscopy reveals that Raman shifts of all phonon modes in SLL films deviate from their respective standard Raman shifts in stress-free crystalline films, confirming the presence of stress in SLL films. It is also shown that tensile and compressive stresses exist in Ge and Ge8Sb92 layers, respectively, which agrees with the lattice mismatch between the Ge and Ge8Sb92 constituent layers. It is also found that the stress reduces with increasing x. Such a thickness dependence of stress can be used to explain the increase in crystallization temperature of four SLL films with x according to stress-enhanced crystallization. Our results reveal a new mechanism to affect the crystallization behaviors of SLL phase-change films besides interfacial effect. Stress and interfacial effects actually coexist and compete in SLL films, which can be used to explain the reported anomalous change in crystallization temperature with the film thickness and cycle number of periods in SLL phase-change films.

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