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This systematic and meta-analytic review aimed to investigate the effects of Tai Chi Chuan (TCC) on the cognitive function of the elderly with cognitive impairment and to analyze the moderators of these effects. We searched eight electronic databases for randomized controlled trials on the effects of TCC on cognitive function, published up to June 14, 2020. The PEDro scale was used to evaluate the methodological quality of the included literature. Stata14.0 software was used for meta-analysis, subgroup analysis, and publication bias testing. A total of 19 studies and 1,970 samples were included. The methodological quality of the included literature was fair to good, and there was no publication bias. Overall, the research shows that the effect of TCC on the elderly with cognitive impairment is statistically significant (SMD = 0.31, p < 0.0001). Five of the cognitive function subdomains were significant moderators [Q (5) = 15.66, p = 0.008 ], and the effect size (ES) was the largest for global cognitive function (SMD = 0.41), followed by executive function (SMD = 0.33), memory (SMD = 0.31), and verbal fluency (SMD = 0.27). Regarding the exercise prescription variables, results were significantly moderated by the length of exercise training [Q (2) = 6.00, p = 0.05 ], with ESs largest for moderate length (SMD = 0.41), followed by short length (SMD = 0.40) and long length (SMD = 0.29). However, the results were not moderated by session time or frequency. TCC can improve multiple cognitive functions of the elderly with cognitive impairment. The intervention effects are moderated by exercise length, but not by exercise session time and frequency. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) are gaining increasing attention and becoming popular in the thermal energy storage field. Microcapsules enhance thermal and mechanical performance of PCMs used in thermal energy storage by increasing the heat transfer area and preventing the leakage of melting materials. Nowadays, a large number of studies about PCM microcapsules have been published to elaborate their benefits in energy systems. In this paper, a comprehensive review has been carried out on PCM microcapsules for thermal energy storage. Five aspects have been discussed in this review: classification of PCMs, encapsulation shell materials, microencapsulation techniques, PCM microcapsules' characterizations, and thermal applications. This review aims to help the researchers from various fields better understand PCM microcapsules and provide critical guidance for utilizing this technology for future thermal energy storage. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) are gaining increasing attention and becoming popular in the thermal energy storage field. Microcapsules enhance thermal and mechanical performance of PCMs used in thermal energy storage by increasing the heat transfer area and preventing the leakage of melting materials. Nowadays, a large number of studies about PCM microcapsules have been published to elaborate their benefits in energy systems. In this paper, a comprehensive review has been carried out on PCM microcapsules for thermal energy storage. Five aspects have been discussed in this review: classification of PCMs, encapsulation shell materials, microencapsulation techniques, PCM microcapsules' characterizations, and thermal applications. This review aims to help the researchers from various fields better understand PCM microcapsules and provide critical guidance for utilizing this technology for future thermal energy storage. [ABSTRACT FROM AUTHOR]

Aluminum alloy AA 6061-T651 and 5A06-H112 rolled plates were successfully welded by friction stir welding (FSW) at three rotation speeds of 600, 900, and 1200 rpm with two transverse speeds of 100 and 150 mm/min. Mechanical properties and strain field evolution of FSW AA 6061-AA 5A06 were characterized by the uniaxial tension and digital image correlation (DIC) tests. Furthermore, the hardness distribution map of whole cross section was obtained via the nanoindentation method with 700 indents. Both DIC and nanoindentation results reveal that the heat-affected zone (HAZ) of AA 6061 alloy is the softest area in the weldment, and the fracture happens in this region. The microstructure evolution characterized by electron-backscatter diffraction (EBSD) indicates that the continuous dynamic recrystallization is the primary grain structure evolution in the stirring zone, and the grain refinement helps improve the mechanical properties. Analyses of the micro- and macrofeatures of the fracture surfaces via scanning electron microscopy (SEM) and optical microscope suggest that the increasing of heat input could enlarge the size of HAZ and reduce the slant angle of HAZ and thus lead the fracture angle to decrease and cause the dimples change from inclined ones to normal ones. [ABSTRACT FROM AUTHOR]