scholarly journals The Design and Manufacture of a Multilayer Low-Temperature Protective Composite Fabric Based on Active Heating Materials and Passive Insulating Materials

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1616
Author(s):  
Sun ◽  
Wang ◽  
Li ◽  
Fan

Based on active heating materials (the phase change microcapsules (microPCMs)) and passive insulating materials (SiO2 aerogel), a new-type multilayer low temperature protective composite fabric (MPF) was designed and manufactured to meet the demands of protection and operation in a short time under a low-temperature environment. Results showed that the MPF consisted of three layers including the fabric layer, the microPCM function layer, and the SiO2 aerogel thermal insulation layer. The differential scanning calorimeter (DSC) results demonstrated that the phase transition enthalpy of the composite was 96.2 J/g during the cooling process. The low-temperature resistance and thermal insulation performance at −50 °C were investigated. The results also demonstrated that the low-temperature resistance time of the MPF was 660 s and the power consumption of the MPFs needed to maintain 37 °C for 10 and 20 min were 629 J and 1872 J, respectively. Compared with the microPCM function layer and the thermal insulation layer, which have the same thickness as the MPF, the low-temperature resistance time of the MPF was prolonged for about 2 and 3 min, respectively. The MPF could provide effective protection of the low-temperature work in a short time and could be applied as potential materials in low-temperature protection.

Author(s):  
Jing Lu ◽  
Jianfeng Gu ◽  
Oudong Hu ◽  
Yunhan Fu ◽  
Dezhan Ye ◽  
...  

The conductive hydrogels have found large application prospects in fabricating flexible multifunctional electronic devices for future-generation wearable human-machine interactions. However, the inferior mechanical strength, low temperature resistance, and non-recyclability induced...


2021 ◽  
Author(s):  
Aiju Meng ◽  
Daxing Wen ◽  
Chunqing Zhang

Spring maize is usually subjected to low-temperature stress during seed germination, which retards seedling growth even if under a suitable temperature. However, the mechanism underlying maize seed germination under low-temperature stress modulating seedling growth after being transferred to normal temperature is still ambiguous. In this study, we used two maize inbred lines with different low-temperature resistance (SM and RM) to investigate the mechanism. The results showed that the SM line had higher lipid peroxidation and lower total antioxidant capacity and germination percentage than the RM line under low-temperature stress, which indicated that the SM line was more vulnerable to low-temperature stress. Further transcriptome analysis revealed that seed germination under low-temperature stress caused down-regulation of photosynthesis related gene ontology (GO) terms in two lines. Moreover, the SM line displayed down-regulation of ribosome and superoxide dismutase (SOD) related genes, whereas genes involved in SOD and vitamin B6 were up-regulated in the RM line. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that photosynthesis and antioxidant metabolism related pathways played important roles in seed germination in response to low-temperature stress, and the photosynthetic system displayed a higher damage degree in the SM line. Both qRT-PCR and physiological characteristics experiments showed similar results with transcriptome data. Taken together, we propose a model for maize seed germination in response to low-temperature stress.


Author(s):  
Zhurinov M.Zh., ◽  
◽  
Teltayev B.B., ◽  
Kalybay A.A., ◽  
Rossi C.O., ◽  
...  

A comparative analysis of the low temperature resistance for a nanocarbon bitumen and other 30 neat and modified bitumens has been performed in the work. The stiffness at the temperatures of -24°С, -30°С and -36°С under technical system Superpave has been accepted as an indicator of low temperature resistance of the bitumens. The stiffness of the bitumens has been determined on a bending beam rheometer (standard ASTM D 6648-08). Before testing the bitumens have been subjected to the double artificial aging: short-term aging – under standard AASHTO Т 240-13 and long-term aging – under standard ASTM D 6521-08. The nanocarbon bitumen has been prepared in the laboratory of the Kazakhstan Highway Research Institute (KazdorNII) with the use of a road bitumen of the grade BND 70/100 produced by the Pavlodar petrochemical plant (PNHZ) and a nanocarbon powder (2% by weight) manufactured from a coal rock of the deposit “Saryadyr” “Corporation “ON-Olzha” LLP, Akmola region, Kazakhstan). The nanocarbon powder (150-200 nm) has been manufactured by three-stage size reduction of the coal rock: I – a mechanical dispergator (up to 2-3 mm), II – an aerodynamic mill (up to 20 mcm), III – a reactor with a rotating electromagnetic field. The neat bitumens of the grades BND 50/70, BND 70/100, BND 100/130 have been produced by the plants of Kazakhstan and Russia; they satisfy the requirements of the standard ST RK 1373-2013. The modified bitumens have been prepared in the laboratory of KazdorNII with the use of the neat bitumens, 7 types of the polymers, crumb rubber and polyphosphoric acid and they satisfy the requirements of the standard ST RK 2534-2014. It has been determined that the nanocarbon bitumen is one of the most resistant at the low temperatures: -24°С, -30°С and -36°С.


2019 ◽  
Vol 21 (4) ◽  
pp. 317 ◽  
Author(s):  
B.B. Teltayev ◽  
A.A. Kalybai ◽  
G.G. Izmailova ◽  
S.R. Rossi ◽  
E.D. Amirbayev ◽  
...  

Physical and chemical indicators of bitumen quality of grade BND 70/100 with the added carbon nanopowder 2% by weight have been studied by laboratory test methods and analysis. High reaction ability of nanopowder particles and concentration of excess surface and internal energy in them have been determined, which provide the increase of low-temperature resistance, aggregate strength, and improvement of rheological properties of nanostructured bitumen. Essential structure variation has been proved: the increase of asphaltenes and oils content for 9% and 7.2% respectively due to the decrease of resins for 16.2% by weight. Methods have been discussed for preparing a liquid nanocarbon mix, adding of the mix into bitumen and homogenization of the bitumen. Some economic indicators have been represented which influence essentially the reduction for the cost value of the nanostructure bitumen.


1996 ◽  
Vol 14 (8) ◽  
pp. 1003-1006 ◽  
Author(s):  
Osamu Ishizaki-Nishizawa ◽  
Toshio Fujii ◽  
Mizue Azuma ◽  
Keiko Sekiguchi ◽  
Norio Murata ◽  
...  

Soft Matter ◽  
2022 ◽  
Author(s):  
Rui Zhao ◽  
Li Jiang ◽  
Ping Zhang ◽  
Dan Li ◽  
Zhenzhong Guo ◽  
...  

In the recent years, a rapid development of the polymeric hydrogel-based sensors has been witnessed. However, conventional hydrogels often exhibit poor mechanical properties. Additionally, the use of these sensors at...


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