scholarly journals Is There Any Linkage between Interstellar Aldehyde and Alcohol?

2021 ◽  
Vol 922 (2) ◽  
pp. 194
Author(s):  
Suman Kumar Mondal ◽  
Prasanta Gorai ◽  
Milan Sil ◽  
Rana Ghosh ◽  
Emmanuel E. Etim ◽  
...  

Abstract It is speculated that there might be some linkage between interstellar aldehydes and their corresponding alcohols. Here an observational study and astrochemical modeling are coupled together to illustrate the connection between them. The ALMA cycle 4 data of a hot molecular core, G10.47+0.03, are utilized for this study. Various aldehydes (acetaldehyde, propanal, and glycolaldehyde), alcohols (methanol and ethylene glycol), and a ketone (acetone) are identified in this source. The excitation temperatures and column densities of these species were derived via the rotation diagram method assuming local thermodynamic equilibrium conditions. An extensive investigation is carried out to understand the formation of these species. Six pairs of aldehyde–alcohol are considered for this study: (i) methanal and methanol, (ii) ethanal and ethanol, (iii) propanal and 1-propanol, (iv) propenal and allyl alcohol, (v) propynal and propargyl alcohol, and (vi) glycolaldehyde and ethylene glycol. One pair of ketone–alcohol (acetone and isopropanol) and ketene–alcohol (ethenone and vinyl alcohol) are also considered. Two successive hydrogenation reactions in the ice phase are examined to form these alcohols from aldehydes, ketone, and ketene, respectively. Quantum chemical methods are extensively executed to review the ice-phase formation route and the kinetics of these species. Based on the obtained kinetic data, astrochemical modeling is employed to derive the abundances of these aldehydes, alcohols, ketone, and ketene in this source. It is seen that our model could successfully explain the observed abundances of various species in this hot molecular core.

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1156
Author(s):  
Dejia Chen ◽  
Lisha Lei ◽  
Meishuai Zou ◽  
Xiaodong Li

The non-isothermal crystallization kinetics of double-crystallizable poly(ethylene glycol)–poly(l-lactide) diblock copolymer (PEG-PLLA) and poly(ethylene glycol) homopolymer (PEG) were studied using the fast cooling rate provided by a Fast-Scan Chip-Calorimeter (FSC). The experimental data were analyzed by the Ozawa method and the Kissinger equation. Additionally, the total crystallization rate was represented by crystallization half time t1/2. The Ozawa method is a perfect success because secondary crystallization is inhibited by using fast cooling rate. The first crystallized PLLA block provides nucleation sites for the crystallization of PEG block and thus promotes the crystallization of the PEG block, which can be regarded as heterogeneous nucleation to a certain extent, while the method of the PEG block and PLLA block crystallized together corresponds to a one-dimensional growth, which reflects that there is a certain separation between the crystallization regions of the PLLA block and PEG block. Although crystallization of the PLLA block provides heterogeneous nucleation conditions for PEG block to a certain extent, it does not shorten the time of the whole crystallization process because of the complexity of the whole crystallization process including nucleation and growth.


Hydrogen ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 101-121
Author(s):  
Sergey P. Verevkin ◽  
Vladimir N. Emel’yanenko ◽  
Riko Siewert ◽  
Aleksey A. Pimerzin

The storage of hydrogen is the key technology for a sustainable future. We developed an in silico procedure, which is based on the combination of experimental and quantum-chemical methods. This method was used to evaluate energetic parameters for hydrogenation/dehydrogenation reactions of various pyrazine derivatives as a seminal liquid organic hydrogen carriers (LOHC), that are involved in the hydrogen storage technologies. With this in silico tool, the tempo of the reliable search for suitable LOHC candidates will accelerate dramatically, leading to the design and development of efficient materials for various niche applications.


1958 ◽  
Vol 50 (9) ◽  
pp. 1283-1288 ◽  
Author(s):  
Julius Roth ◽  
F. S. Stow ◽  
D. L. Kouba
Keyword(s):  

Biochemistry ◽  
1985 ◽  
Vol 24 (14) ◽  
pp. 3814-3820 ◽  
Author(s):  
J. A. Biosca ◽  
F. Travers ◽  
T. E. Barman ◽  
R. Bertrand ◽  
E. Audemard ◽  
...  

1997 ◽  
Vol 67 (10) ◽  
pp. 760-766 ◽  
Author(s):  
M.-C. Yang ◽  
H.-Y. Tsai

Poly(ethylene terephthalate) fabrics are treated with sodium hydroxide using ethylene glycol or glycerin as the solvent. Compared with conventional aqueous alkaline hydrolysis, the degradation rate in ethylene glycol increases tenfold. The kinetics of the alkaline-ethylene glycol treatment show that the weight loss is linear with respect to time. The moisture regain rate and tensile properties of the treated fabrics are measured; other tests include scanning electron microscopy and dyeing properties. The results show that the properties of the treated fabrics do not depend significantly on the solvent; therefore, using ethylene glycol can greatly shorten the treatment time to achieve results similar to those with the conventional aqueous system.


Coatings ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 99 ◽  
Author(s):  
Ji-Won Park ◽  
Jong-Gyu Lee ◽  
Gyu-Seong Shim ◽  
Hyun-Joong Kim ◽  
Young-Kwan Kim ◽  
...  

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