scholarly journals Investigation of Thermal/hygrothermal Aging Effects on the Ignition Characteristics of Ti Metal-based Pyrotechnics and Construction of the Aging Models

2021 ◽  
Vol 25 (3) ◽  
pp. 26-41
Author(s):  
Juyoung Oh ◽  
Jai-ick Yoh
2021 ◽  
pp. 002199832110539
Author(s):  
Shervin Jodatnia ◽  
Samrand Rash-Ahmadi

This paper aimed to evaluate hygrothermal aging effects on polymethyl methacrylate modified with TiO2, SiO2, and Al2O3 nanoparticles in 0.5, 1, and 2% weight fractions. The distribution of nanoparticles was characterized by the scanning electron microscopy (SEM) method. Moisture absorption behavior and mechanical properties of samples in terms of elastic modulus, tensile strength, impact strength, and hardness were investigated. Furthermore, the coefficient of hygrothermal expansion (CHE) for each sample was calculated thanks to experimental data. Finally, by applying the multi-criteria decision making (MCDM) technique, the optimum composition for superior performance was obtained in 0.5 wt% of nanoparticles, more specifically for SiO2.


2020 ◽  
Vol 21 (22) ◽  
pp. 8439
Author(s):  
Kyung-Eun Lee ◽  
Sugyeong Jeong ◽  
Seok Kyun Yun ◽  
Seoyeon Kyung ◽  
Abadie Sophie ◽  
...  

In recent years, a number of active materials have been developed to provide anti-aging benefits for skin and, among them, peptides have been considered the most promising candidate due to their remarkable and long-lasting anti-wrinkle activity. Recent studies have begun to elucidate the relationship between the secretion of emotion-related hormones and skin aging. Kisspeptin, a neuropeptide encoded by the KISS1 gene, has gained attention in reproductive endocrinology since it stimulates the reproductive axis in the hypothalamus; however, the effects of Kisspeptin on skin have not been studied yet. In this study, we synthesized Kisspeptin-10 and Kisspeptin-E, which are biologically active fragments, to mimic the action of Kisspeptin. Next, we demonstrated the anti-aging effects of the Kisspeptin-mimicking fragments using UV-induced skin aging models, such as UV-induced human dermal fibroblasts (Hs68) and human skin explants. Kisspeptin-E suppressed UV-induced 11 beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) stimulation leading to a regulation of skin aging related genes, including type I procollagen, matrix metalloproteinases-1 (MMP-1), interleukin-6 (IL-6), and IL-8, and rescued the skin integrity. Taken together, these results suggest that Kisspeptin-E could be useful to improve UV-induced skin aging by modulating expression of stress related genes, such as 11β-HSD1.


2014 ◽  
Vol 110 ◽  
pp. 464-472 ◽  
Author(s):  
Yinghui Hu ◽  
Augustus W. Lang ◽  
Xiaochen Li ◽  
Steven R. Nutt

Langmuir ◽  
2013 ◽  
Vol 30 (1) ◽  
pp. 165-171 ◽  
Author(s):  
John N. Myers ◽  
Chi Zhang ◽  
Kang-Wook Lee ◽  
Jaimal Williamson ◽  
Zhan Chen

2017 ◽  
Vol 110 ◽  
pp. 213-228 ◽  
Author(s):  
Haohui Xin ◽  
Ayman Mosallam ◽  
Yuqing Liu ◽  
Fei Yang ◽  
Youyou Zhang

2019 ◽  
Vol 96 (14) ◽  
pp. 1233-1257 ◽  
Author(s):  
Wei Feng ◽  
Fei Xu ◽  
Wei Xie ◽  
Yuyan Zang ◽  
Xiaoyu Zhang

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