scholarly journals Biosynthesis and Characteristics of Polyhydroxyalkanoates. 1. Polyhydroxybutyrates of Azotobacter vinelandii N-15

2020 ◽  
Vol 14 (4) ◽  
pp. 463-467
Author(s):  
Ihor Semeniuk ◽  
◽  
Tetyana Pokynbroda ◽  
Viktoria Kochubei ◽  
Halyna Midyana ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Contact Angle ◽  
Melting Point ◽  
Carbon Source ◽  
Azotobacter Vinelandii ◽  
Cell Mass ◽  
Film Surface ◽  
High Thermal Stability ◽  
Wetting Contact Angle ◽  
Biopolymer Film

The biosynthesis of cellular polymers of Azotobacter vinelandii N-15 strain using molasses as a carbon source has been optimized. The highest yield of polymer (25.8 % of cell mass) was obtained on a nutrient medium with a molasses concentration of 50 g/l. Using TL-chromatography and IR-spectroscopy the obtained product was identified as polyhydroxybutyrate (PHB), and its properties were investigated. The wetting contact angle was used to characterize the biopolymer film surface properties. According to the results of thermal and thermomechanical studies, it was found that the obtained РHB is characterized by a high thermal stability and heat resistance: the melting point is 462 K; deep destruction and thermooxidative processes begin at the temperatures above 567 K.

Development of Molten Salt Heat Transfer Fluid With Low Melting Point and High Thermal Stability

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Justin W. Raade ◽  
David Padowitz
Keyword(s):  
Heat Transfer ◽  
Thermal Stability ◽  
Melting Point ◽  
Molten Salt ◽  
Solar Power ◽  
Stability Limit ◽  
High Thermal Stability ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
Concentrating Solar Power

This paper describes an advanced heat transfer fluid (HTF) consisting of a novel mixture of inorganic salts with a low melting point and high thermal stability. These properties produce a broad operating range molten salt and enable effective thermal storage for parabolic trough concentrating solar power plants. Previous commercially available molten salt heat transfer fluids have a high melting point, typically 140 °C or higher, which limits their commercial use due to the risk of freezing. The advanced HTF embodies a novel composition of materials, consisting of a mixture of nitrate salts of lithium, sodium, potassium, cesium, and calcium. This unique mixture exploits eutectic behavior resulting in a low melting point of 65 °C and a thermal stability limit over 500 °C. The advanced HTF described in this work was developed using advanced experiment design and data analysis methods combined with a powerful high throughput experimental workflow. Over 5000 unique mixtures of inorganic salt were tested during the development process. Additional work is ongoing to fully characterize the relevant thermophysical properties of the HTF and to assess its long term performance in realistic operating conditions for concentrating solar power applications or other high temperature processes.

Thermodynamic modeling and experimental verification of a NaNO3–KNO3–LiNO3–Ca(NO3)2 system for solar thermal energy storage

2017 ◽  
Vol 41 (18) ◽  
pp. 10376-10382 ◽  
Author(s):  
Fang Xu ◽  
Juntao Wang ◽  
Xiaoming Zhu ◽  
Xiaoling Liu
Keyword(s):  
Thermal Stability ◽  
Energy Storage ◽  
Melting Point ◽  
Thermal Energy ◽  
Experimental Verification ◽  
Heat Storage ◽  
High Thermal Stability ◽  
Storage Medium ◽  
Solar Thermal Energy ◽  
Molten Mixture

A quaternary molten mixture was prepared to be a heat storage medium with a low melting point and high thermal stability.

Wide-bandgap bipolar material with high thermal stability

2019 ◽  
pp. 903
Author(s):  
Sheng-Chieh Lin ◽  
Yu-Chieh Cheng ◽  
Man-Kit Leung ◽  
Jiun-Haw Lee ◽  
Tien-Lung Chiu
Keyword(s):  
Thermal Stability ◽  
Wide Bandgap ◽  
High Thermal Stability

New Deep Blue Emitting Materials Based on Indenopyrazine Core with High Thermal Stability

2011 ◽  
Vol 11 (5) ◽  
pp. 4639-4643 ◽  
Author(s):  
Chang-Hun Seok ◽  
Young-Il Park ◽  
Soo-Kang Kim ◽  
Ji-Hoon Lee ◽  
Jongwook Park
Keyword(s):  
Thermal Stability ◽  
High Thermal Stability ◽  
Deep Blue

Comparative studies of nitrogen plasma and argon plasma treatment on the strength of PBO fibre reinforced high-temperature resistant thermoplastic composite

2021 ◽  
pp. 095400832098729
Author(s):  
K Sudheendra ◽  
Jennifer Vinodhini ◽  
M Govindaraju ◽  
Shantanu Bhowmik
Keyword(s):  
Contact Angle ◽  
High Temperature ◽  
Plasma Treatment ◽  
Sessile Drop ◽  
Dynamic Contact Angle ◽  
Argon Plasma ◽  
Film Surface ◽  
Fibre Surface ◽  
Nitrogen Plasma ◽  
Thermoplastic Composite

The study involves the processing of a novel poly [1, 4-phenylene-cis-benzobisoxazole] (PBO) fibre reinforced high-temperature thermoplastic composite with polyaryletherketone (PAEK) as the matrix. The PBO fibre and the PAEK film surface was modified using the method of argon and nitrogen plasma treatment. The investigation primarily focuses on evaluating the tensile properties of the fabricated laminates and correlating it with the effect of plasma treatment, surface characteristics, and its fracture surface. A 5% decrease in tensile strength was observed post argon plasma treatment while a 27% increase in strength was observed post nitrogen plasma treatment. The morphology of the failure surface was investigated by scanning electron microscopy and an interfacial failure was observed. Furthermore, the effect of plasma on the wettability of PBO fibres and PAEK film surface was confirmed by the Dynamic Contact Angle analysis and sessile drop method respectively. FTIR spectral analysis was done to investigate the effect of plasma treatment on the chemical structure on the surface. The results of the wettability study showed that the argon plasma treatment of the fibre surface increased its hydrophobicity while nitrogen plasma treatment resulted in the reduction of contact angle.

scholarly journals Improved thermally stable oligoetherols from 6-aminouracil, ethylene carbonate and boric acid

2019 ◽  
Vol 17 (1) ◽  
pp. 1080-1086
Author(s):  
Elżbieta Chmiel-Szukiewicz
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Boric Acid ◽  
Ethylene Carbonate ◽  
Pyrimidine Ring ◽  
Polyurethane Foams ◽  
High Thermal Stability ◽  
H Nmr ◽  
Maldi Tof ◽  
Instrumental Methods

AbstractSyntheses of oligoetherols with a 1,3-pyrimidine ring and boron atoms using 6-aminouracil, ethylene carbonate and boric acid has been proposed. The structure of the obtained products were determined by instrumental methods (IR, 1H-NMR and MALDI-ToF spectra). The physicochemical and thermal properties of oligoetherols were examined. The products were characterized by high thermal stability. Based on the tests performed, it was found that oligoetherols obtained from 6-aminouracil, boric acid and ethylene carbonate are suitable for the manufacturing of polyurethane foams with improved thermal stability and reduced flammability.

Sr3LiTaO6:xMn4+ red-emitting phosphors for indoor plant growth lighting: High thermal stability and quantum efficiency

2021 ◽  
pp. 118234
Author(s):  
Yunlong Yang ◽  
Linyan Fu ◽  
Xuefei Ren ◽  
Yingjie Zhu ◽  
Jiajie Zhu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Plant Growth ◽  
Quantum Efficiency ◽  
High Thermal Stability
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