High-Pressure Adsorption of Supercritical Gases on Activated Carbons:  An Improved Approach Based on the Density Functional Theory and the Bender Equation of State

Langmuir ◽  
2003 ◽  
Vol 19 (20) ◽  
pp. 8349-8357 ◽  
Author(s):  
E. A. Ustinov ◽  
D. D. Do
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Equation Of State ◽  
Density Functional ◽  
Activated Carbons ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
High Pressure Adsorption

Structural, elastic and vibrational properties of nanocrystalline lutetium gallium garnet under high pressure

2015 ◽  
Vol 17 (14) ◽  
pp. 9454-9464 ◽  
Author(s):  
V. Monteseguro ◽  
P. Rodríguez-Hernández ◽  
H. M. Ortiz ◽  
V. Venkatramu ◽  
F. J. Manjón ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Ab Initio ◽  
Density Functional ◽  
Vibrational Properties ◽  
Functional Theory ◽  
The Density Functional Theory

An ab initio study of the structural, elastic and vibrational properties of the lutetium gallium garnet (Lu3Ga5O12) under pressure has been performed in the framework of the density functional theory, up to 95 GPa.

Firs-Principles Investigation of the Electronic and Optical Properties of B-Doped ZnO under Pressure

2019 ◽  
Vol 807 ◽  
pp. 115-120
Author(s):  
Ling Ping Xiao ◽  
Yun Qin Liu
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Pressure Effects ◽  
Partial Density ◽  
Electronic Band ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Doped Zno

Based on the density functional theory (DFT), the first-principles approach is used to study the electronic band structure of B-doped wuritzite ZnO with different pressure. The pressure effects on the lattice parameters, electronic band structures, and partial density of states (PDOS) of crystalline B-doped ZnO are calculated up to 8 GPa. Moreover, the evolution of the dielectric function, absorption coefficient (), reflectivity (), and the real part of the refractive index () at high pressure are also presented. Keywords: high pressure; density functional theory; B-doped ZnO.

scholarly journals Modeling giant planets and brown dwarfs

2010 ◽  
Vol 6 (S276) ◽  
pp. 473-474
Author(s):  
Andreas Becker ◽  
Nadine Nettelmann ◽  
Ulrike Kramm ◽  
Winfried Lorenzen ◽  
Martin French ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
High Pressure ◽  
Equation Of State ◽  
Density Functional ◽  
Brown Dwarfs ◽  
Md Simulations ◽  
Giant Planets ◽  
Functional Theory ◽  
State Data

AbstractWe present new results in modeling the interiors of Giant Planets (GP) and Brown Dwarfs (BD). In general models of the interior rely on equation of state data for planetary materials which have considerable uncertainties in the high-pressure domain. Our calculations are based on ab initio equation of state (EOS) data for hydrogen, helium, hydrogen-helium mixtures and water as the representative of all heavier elements or ices using finite-temperature density functional theory molecular dynamics (FT-DFT-MD) simulations. We compare results for the BD Gliese 229B calculated with Saumon-Chabrier-Van Horn EOS (SCVH95) and our EOS data.

scholarly journals Electron-phonon interaction in In-induced √7 ×√3 structures on Si(111) from first-principles

2021 ◽  
Author(s):  
I. Yu. Sklyadneva ◽  
Rolf Heid ◽  
Pedro Miguel Echenique ◽  
Evgueni Chulkov
Keyword(s):  
Density Functional Theory ◽  
Double Layer ◽  
First Principles ◽  
Linear Response ◽  
Density Functional ◽  
Single Layer ◽  
Phonon Interaction ◽  
Functional Theory ◽  
Electron Phonon Interaction ◽  
The Density Functional Theory

Electron-phonon interaction in the Si(111)-supported rectangular √(7 ) ×√3 phases of In is investigated within the density-functional theory and linear-response. For both single-layer and double-layer √(7 ) ×√3 structures, it...

scholarly journals An Evaluation of the Impact of the Amount of Potassium Hydroxide on the Porous Structure Development of Activated Carbons

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Mirosław Kwiatkowski ◽  
Elżbieta Broniek ◽  
Vanessa Fierro ◽  
Alain Celzard
Keyword(s):  
Density Functional Theory ◽  
Porous Structure ◽  
Potassium Hydroxide ◽  
Density Functional ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Appropriate Technology ◽  
Functional Theory ◽  
Homogeneous Surface ◽  
The Impact

This paper presents the results of an evaluation of the impact of the amount of potassium hydroxide on the obtained porous structure of the activated carbons derived from the shells of pistachios, hazelnuts, and pecans by carbonization and subsequent chemical activation with potassium hydroxide by different adsorption methods: Brunauer–Emmett–Teller, Dubinin–Raduskevich, the new numerical clustering-based adsorption analysis, Quenched Solid Density Functional Theory, and 2D-Non-linear Density Functional Theory for Heterogeneous Surfaces, applied to nitrogen adsorption isotherms at −196 °C. Based on the conducted research, a significant potential for the production of activated carbons from waste materials, such as nut shells, has been demonstrated. All the activated carbons obtained in the present study at the activator/char mass ratio R = 4 exhibited the most developed porous structure, and thus very good adsorption properties. However, activated carbons obtained from pecan shells deserve special attention, as they were characterized by the most homogeneous surface among all the samples analyzed, i.e., by a very desirable feature in most adsorption processes. The paper demonstrates the necessity of using different methods to analyze the porous structure of activated carbons in order to obtain a complete picture of the studied texture. This is because only a full spectrum of information allows for correctly selecting the appropriate technology and conditions for the production of activated carbons dedicated to specific industrial applications. As shown in this work, relying only on the simplest methods of adsorption isotherm analysis can lead to erroneous conclusions due to lack of complete information on the analyzed porous structure. This work thus also explains how and why the usual characterizations of the porous structure of activated carbons derived from lignocellulosic biomass should not be taken at face value. On the contrary, it is advisable to cross reference several models to get a precise idea of the adsorbent properties of these materials, and therefore to propose the most suitable production technology, as well as the conditions of the preparation process.

scholarly journals Study on the interaction between catechin and cholesterol by the density functional theory

2020 ◽  
Vol 18 (1) ◽  
pp. 357-368
Author(s):  
Kaiwen Zheng ◽  
Kai Guo ◽  
Jing Xu ◽  
Wei Liu ◽  
Junlang Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Charge Transfer ◽  
Density Functional ◽  
Antioxidant Properties ◽  
Micelle Formation ◽  
Aromatic Rings ◽  
Hydrogen Bond Interaction ◽  
Functional Theory ◽  
The Density Functional Theory

AbstractCatechin – a natural polyphenol substance – has excellent antioxidant properties for the treatment of diseases, especially for cholesterol lowering. Catechin can reduce cholesterol content in micelles by forming insoluble precipitation with cholesterol, thereby reducing the absorption of cholesterol in the intestine. In this study, to better understand the molecular mechanism of catechin and cholesterol, we studied the interaction between typical catechins and cholesterol by the density functional theory. Results show that the adsorption energies between the four catechins and cholesterol are obviously stronger than that of cholesterol themselves, indicating that catechin has an advantage in reducing cholesterol micelle formation. Moreover, it is found that the molecular interactions of the complexes are mainly due to charge transfer of the aromatic rings of the catechins as well as the hydrogen bond interactions. Unlike the intuitive understanding of a complex formed by hydrogen bond interaction, which is positively correlated with the number of hydrogen bonds, the most stable complexes (epicatechin–cholesterol or epigallocatechin–cholesterol) have only one but stronger hydrogen bond, due to charge transfer of the aromatic rings of catechins.

A trinuclear chromium(III) chlorocarbyne

2021 ◽  
Author(s):  
Takashi Kurogi ◽  
Keiichi Irifune ◽  
Takahiro Enoki ◽  
Kazuhiko Takai
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Terminal Alkynes ◽  
Functional Theory ◽  
The Density Functional Theory

Reduction of CCl4 by CrCl2 in THF afforded a trinuclear chromium(III) carbyne [CrCl(thf)2)]3(μ3-CCl)(μ-Cl)3. The chlorocarbyne complex reacted with aldehydes to afford chloroallylic alcohols and terminal alkynes. The density functional theory...

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