Examination of proline, hydroxyproline and pyroglutamic acid with different polar groups by terahertz spectroscopy

Author(s):  
Zhenqi Zhu ◽  
Yujing Bian ◽  
Xun Zhang ◽  
Ruonan Zeng ◽  
Bin Yang
Author(s):  
Zhipeng Wu ◽  
Zhongjie Zhu ◽  
Chao Cheng ◽  
Jianbing Zhang ◽  
Yan Gong ◽  
...  

Author(s):  
V.A. Munoz ◽  
R.J. Mikula ◽  
C. Payette ◽  
W.W. Lam

The transformation of high molecular weight components present in heavy oils into useable liquid fuels requires their decomposition by means of a variety of processes. The low molecular weight species produced recombine under controlled conditions to generate synthetic fuels. However, an important fraction undergo further recombination into higher molecular weight components, leading to the formation of coke. The optical texture of the coke can be related to its originating components. Those with high sulfur and oxygen content tend to produce cokes with small optical texture or fine mosaic, whereas compounds with relatively high hydrogen content are likely to produce large optical texture or domains. In addition, the structure of the parent chemical components, planar or nonplanar, determines the isotropic or anisotropic character of the coke. Planar molecules have a tendency to align in an approximately parallel arrangement to initiate the formation of the nematic mesophase leading to the formation of anisotropic coke. Nonplanar highly alkylated compounds and/or those rich in polar groups form isotropic coke. The aliphatic branches produce steric hindrance to alignment, whereas the polar groups participate in cross-linking reactions.


2020 ◽  
Vol 63 (7) ◽  
pp. 708-720 ◽  
Author(s):  
V L Vaks ◽  
V A Anfertev ◽  
V Yu Balakirev ◽  
S A Basov ◽  
E G Domracheva ◽  
...  

PIERS Online ◽  
2010 ◽  
Vol 6 (4) ◽  
pp. 390-394 ◽  
Author(s):  
Tadao Nagatsuma ◽  
Akira Kaino ◽  
Shintaro Hisatake ◽  
Katsuhiro Ajito ◽  
Ho-Jin Song ◽  
...  

Author(s):  
S. Senali Dissanayake ◽  
Naheed Ferdous ◽  
Hemi Gandhi ◽  
Eric Mazur ◽  
Elif Ertekin ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1841
Author(s):  
Kang Li ◽  
Xuejie Zhang ◽  
Yan Qin ◽  
Ying Li

Aerogels have been widely used in the adsorption of pollutants because of their large specific surface area. As an environmentally friendly natural polysaccharide, cellulose is a good candidate for the preparation of aerogels due to its wide sources and abundant polar groups. In this paper, an approach to construct cellulose nanofibers aerogels with both the good mechanical property and the high pollutants adsorption capability through chemical crosslinking was explored. On this basis, TiO2 nanoparticles were loaded on the aerogel through the sol-gel method followed by the hydrothermal method, thereby the enriched pollutants in the aerogel could be degraded synchronously. The chemical cross-linker not only helps build the three-dimensional network structure of aerogels, but also provides loading sites for TiO2. The degradation efficiency of pollutants by the TiO2@CNF Aerogel can reach more than 90% after 4 h, and the efficiency is still more than 70% after five cycles. The prepared TiO2@CNF Aerogels have high potential in the field of environmental management, because of the high efficiency of treating organic pollutes and the sustainability of the materials. The work also provides a choice for the functional utilization of cellulose, offering a valuable method to utilize the large amount of cellulose in nature.


2021 ◽  
Author(s):  
Seiichiro Ariyoshi ◽  
Satoshi Ohnishi ◽  
Hikaru Mikami ◽  
Hideto Tsuji ◽  
Yuki Arakawa ◽  
...  

Poly(L-lactide) (PLLA) was investigated by Fourier transform terahertz (THz) spectroscopy over the frequency range of 1.0 – 8.5 THz. THz absorption spectra were acquired for PLLA samples isothermally crystallized at...


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