The reaction of free radicals and functional groups during coal oxidation at low temperature under different oxygen concentrations

2021 ◽  
Vol 150 ◽  
pp. 148-156
Author(s):  
Buzhuang Zhou ◽  
Shengqiang Yang ◽  
Xiaoyuan Jiang ◽  
Jiawen Cai ◽  
Qin Xu ◽  
...  
Fuel ◽  
2019 ◽  
Vol 239 ◽  
pp. 429-436 ◽  
Author(s):  
Qin Xu ◽  
Shengqiang Yang ◽  
Xincheng Hu ◽  
Wanxin Song ◽  
Jiawen Cai ◽  
...  

2020 ◽  
Vol 142 (2) ◽  
pp. 899-912 ◽  
Author(s):  
Yang Xiao ◽  
Tao Guo ◽  
Chi-Min Shu ◽  
Qing-Wei Li ◽  
Da-Jing Li ◽  
...  

2018 ◽  
Vol 141 ◽  
pp. 333-338 ◽  
Author(s):  
Jun Li ◽  
Pengbin Fu ◽  
Qiren Zhu ◽  
Yandong Mao ◽  
Cheng Yang

1980 ◽  
Vol 34 (2) ◽  
pp. 171-173 ◽  
Author(s):  
D. G. Mead

Low temperature Fourier transform infrared measurements at 20 K on some wafers containing substitutional atomic carbon and oxygen are presented. Spectral subtraction techniques at 20 K indicate an increase of approximately 5 times in sensitivity compared to the room temperature evaluation of the carbon and oxygen concentrations.


1982 ◽  
Vol 36 (1) ◽  
pp. 52-57 ◽  
Author(s):  
L. S. Singer ◽  
I. C. Lewis

The applications of electron spin resonance (ESR) to carbonaceous materials are reviewed. The stable paramagnetic species observed in the products of low-temperature pyrolysis are odd-alternate neutral free radicals, whereas the unpaired spins of higher temperature carbons and graphites are primarily conduction electrons. The variety of ESR properties and phenomena requires special attention to techniques of measurement and interpretations of results. The relevance to the carbonization process of the free radicals observed by ESR is also discussed.


AIMS Energy ◽  
2017 ◽  
Vol 5 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Vladimir A. Kaminsky ◽  
◽  
Nina Yu. Obvintseva ◽  
Svetlana A. Epshtein

2021 ◽  
Vol 16 (3) ◽  
pp. 517-524
Author(s):  
Poppy Puspitasari ◽  
A. Muhammad ◽  
A. A. Permanasari ◽  
T. Pasang ◽  
S. M. S. N. S. Zahari ◽  
...  

Samarium cobalt is known as super high density magnetic material with large magnetic anisotropy energy. Samarium–cobalt exhibits manipulative magnetic properties as a rare-earth material which has different properties in a low sintering temperature. It is therefore of paramount importance to investigate samarium cobalt (Sm2Co17) magnetic properties in the low temperature sintering condition. Sm2Co17, which is utilized in this research, is synthesized via the sol–gel process at sintering temperatures of 400, 500, and 600 °C. Subsequently, the crystallites indicate the formation of a single-phase Sm2Co17 on all the samples in all temperature variations. Moreover, the peaks in the X-ray diffraction analysis of crystallite sizes calculated using the Scherrer equation are 17.730, 15.197, and 13.296 nm at 400, 500, and 600 °C. Through scanning electron microscopy, the particles are found to be relatively large and agglomerated, with average sizes of 143.65, 168.78, and 237.26 nm. The functional groups are also analyzed via Fourier-transform infrared spectroscopy, which results in the appearance of several bonds in the samples, for example, alkyl halides, alkanes, and esters with aromatic functional groups on the fingerprint area and alkynes, alkyl halides, and alcohol functional groups at a wavelength of above 1500 cm. The test results of the magnetic properties using vibrating-sample magnetometer (VSM) revealed high coercivity and retentivity in the samples sintered at 400 °C. However, the highest saturation occurs in the samples sintered at 600 ℃. At a low sintering temperature (below 1000 °C), samarium cobalt shows as the soft magnetic material. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 


Fuel ◽  
2020 ◽  
Vol 278 ◽  
pp. 118407 ◽  
Author(s):  
Jing Gao ◽  
Rui-zhi Chu ◽  
Xian-liang Meng ◽  
Jian-yun Yang ◽  
De-guang Yang ◽  
...  

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