Measuring energy-entropy competition and compensation in chemical reactions: a theoretical study of the role of entropy in the formation of Van Der Waa

1987 ◽  
Vol 118 ◽  
pp. 79-96 ◽  
Author(s):  
Zdeněk Slanina
Keyword(s):  
Chemical Reactions ◽  
Theoretical Study ◽  
Energy Entropy

Fine structure and properties of defects in naturally occurring silicates and oxides

1990 ◽  
Vol 48 (4) ◽  
pp. 460-461
Author(s):  
David R. Veblen
Keyword(s):  
Chemical Reactions ◽  
High Resolution Electron Microscopy ◽  
Extended Defects ◽  
Single Chain ◽  
Naturally Occurring ◽  
Resolution Electron ◽  
Fine Structures ◽  
Image Simulations ◽  
Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

Role of Man in Production and Social Systems Based on Digital Technologies

2020 ◽  
pp. 6-13
Author(s):  
V. K. Potemkin
Keyword(s):  
Theoretical Study ◽  
Social Systems ◽  
Digital Technologies ◽  
Changing Role ◽  
Consistent Approach ◽  
Social Improvement

The article presents the results of a theoretical study of the influence processes of the developed digital technologies and the activities of enterprises and organizations on the changing role of man in labor and their social improvement. The necessity of a balanced and consistent approach to create conditions for the use of digital technologies in practical activities and determining the con- sequences not only in enterprises and organizations, but also in the conscious behavior and social realities of all workers, without exception, is substantiated. The main directions of the development of digital technologies are determined, involving the wide participation of workers in their use in enterprises and organizations.

scholarly journals The Role of La2O3 in Enhancement the Radiation Shielding Efficiency of the Tellurite Glasses: Monte-Carlo Simulation and Theoretical Study

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3913
Author(s):  
Aljawhara H. Almuqrin ◽  
Mohamed Hanfi ◽  
K. G. Mahmoud ◽  
M. I. Sayyed ◽  
Hanan Al-Ghamdi ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Theoretical Study ◽  
Radiation Shielding ◽  
Photon Flux ◽  
Transmission Factor ◽  
Tellurite Glasses ◽  
Attenuation Coefficients ◽  
Binary Glass ◽  
Buildup Factors

The radiation shielding competence was examined for a binary glass system xLa2O3 + (1 − x) TeO2 where x = 5, 7, 10, 15, and 20 mol% using MCNP-5 code. The linear attenuation coefficients (LACs) of the glasses were evaluated, and it was found that LT20 glass has the greatest LAC, while LT5 had the least LAC. The transmission factor (TF) of the glasses was evaluated against thicknesses at various selected energies and was observed to greatly decrease with increasing thickness; for example, at 1.332 MeV, the TF of the LT5 glass decreased from 0.76 to 0.25 as the thickness increased from 1 to 5 cm. The equivalent atomic number (Zeq) of the glasses gradually increased with increasing photon energy above 0.1 MeV, with the maximum values observed at around 1 MeV. The buildup factors were determined to evaluate the accumulation of photon flux, and it was found that the maximum values for both can be seen at around 0.8 MeV. This research concluded that LT20 has the greatest potential in radiation shielding applications out of the investigated glasses due to the glass having the most desirable parameters.

Role of (H2O)n (n = 2–3) Clusters on the HO2 + O3 Reaction: A Theoretical Study

2015 ◽  
Vol 120 (8) ◽  
pp. 1560-1568 ◽  
Author(s):  
Luís P. Viegas ◽  
António J. C. Varandas
Keyword(s):  
Theoretical Study

Theoretical study on the role of cooperative solvent molecules in the neutral hydrolysis of ketene

2010 ◽  
Vol 127 (5-6) ◽  
pp. 493-506 ◽  
Author(s):  
Xiao-Peng Wu ◽  
Xi-Guang Wei ◽  
Xiao-Ming Sun ◽  
Yi Ren ◽  
Ning-Bew Wong ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Solvent Molecules ◽  
Hydrolysis Of

General promoting effect of polydopamine on supported noble metal catalysts

2017 ◽  
Vol 5 (39) ◽  
pp. 20789-20796 ◽  
Author(s):  
Mingwei Zhang ◽  
Guozhu Li ◽  
Xiaoqing Sun ◽  
Yujiao Jiang ◽  
Xiangwen Zhang
Keyword(s):  
Noble Metal ◽  
Theoretical Study ◽  
Metal Catalysts ◽  
Promoting Effect ◽  
Noble Metal Catalysts

A joint experimental–theoretical study has been conducted to investigate the role of polydopamine as an interface facilitator for supported noble metal catalysts.

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