Computer Simulation Study of Adsorption, Isosteric Heat and Phase Transitions of Methane on Graphite

1992 ◽  
Vol 290 ◽  
Author(s):  
Shaoyi Jiang ◽  
Keith E. Gubbins
Keyword(s):  
Isosteric Heat ◽  
Graphite Substrate ◽  
Ensemble Monte Carlo ◽  
Adsorbed Films ◽  
Heat Curve ◽  
First Time ◽  
Grand Canonical ◽  
Adsorption Of Methane ◽  
Incommensurate Phases ◽  
Good Agreement

AbstractWe report Canonical (NVTMC), Grand Canonical (GOMC) and Gibbs Ensemble Monte Carlo (GEMC) simulations for adsorption of methane on graphite. Lennard-Jones (LJ) potentials are used for the intermolecular interactions, and both structured and structureless (10–4–3) solid-fluid potentials are considered. Several sets of methane-methane L.I parameters have been used in the literature, and we compare results obtained with these sets throughout our simulations. The adsorption isotherm and isosteric heat curve are obtained at 77.5 K and found in good agreement with experiments. The commensurateincommensurate transition (CIT) of methane on a graphite substrate with periodically varying adsorbate-adsorbent potential at 40.0 K is studied and is in qualitative agreement with experiment. The effect of varying the corrugation of the fluid-wall potential on the commensurate and incommensurate phases is explored. The GEMC simulations have been carried out to study the vapor-liquid equilibrium (VLE) of a two-dimensional (2D) LJ fluid with system sizes up to 3000 particles. The effect of system sizes on the critical behavior is investigated. The GEMC method has also been successfully applied to study the VLE in 2D adsorbed films for the first time.

Computer Simulation in Actived Carbon Pores for Methane Storage

2011 ◽  
Vol 63-64 ◽  
pp. 1022-1025
Author(s):  
Ke Rong He
Keyword(s):  
Local Density ◽  
Density Profiles ◽  
Pore Sizes ◽  
Ensemble Monte Carlo ◽  
Lennard Jones ◽  
Slit Pore ◽  
Actived Carbon ◽  
Fluid Interaction ◽  
Grand Canonical ◽  
Adsorption Of Methane

In this paper, adsorption of methane in actived carbon pores has been simulated by using the grand canonical ensemble Monte Carlo (GCMC) method. In the simulation, Lennard-Jones (LJ) potential is used for represent the fluid-fluid interaction, and the 10-4-3 potential is used for represent the interaction between fluid molecules and a slit carbon wall. Firstly, the adsorption isotherms of methane in actived carbon pores and local density profiles of methane in slit pore are obtained. Then, the interaction energy of methane in slit carbon pores with nine different pore sizes is obtained. Finally, the temperature, pressures, pore sizes affect the adsorption amount was studied, respectively.

Optimaization of Single-Walled Carbon Nanotube for Adsorption of Methane

2011 ◽  
Vol 291-294 ◽  
pp. 490-493
Author(s):  
Ke Rong He
Keyword(s):  
Carbon Nanotube ◽  
Single Walled Carbon Nanotube ◽  
Jones Potential ◽  
Single Walled Carbon ◽  
Ensemble Monte Carlo ◽  
Lennard Jones ◽  
Methods Of Calculation ◽  
Fluid Interaction ◽  
Grand Canonical ◽  
Adsorption Of Methane

In this paper, methane adsorption in single-walled carbon nanotube (SWNT) has been simulated by using the grand canonical ensemble Monte Carlo (GCMC) method. Lennard-Jones (LJ) potential is used to represent the fluid-fluid interaction, Lennard-Jones potential and integral method are used to calculation of the potential between fluid molecules and carbon atoms, respectively. In the simulation, two methods of calculation of potential between fluid molecules and SWNT are compared. The potential calculated by the two methods are almost the same. Then the influence of diameter of SWNT on the usable capacity ratio (UCR) is analyzed, and the parameters of the SWNT which has the best adsorption performance at 300K is recommended under certain pressure.

Multicanonical Molecular Dynamics Simulation Study of the Liquid-Solid and Solid-Solid Transitions in Lennard-Jones Clusters

2011 ◽  
Author(s):  
Toshihiro Kaneko ◽  
Kenji Yasuoka ◽  
Ayori Mitsutake ◽  
Xiao Cheng Zeng
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Transition Temperature ◽  
Peak Position ◽  
Temperature Curve ◽  
Dynamics Simulation ◽  
Lennard Jones ◽  
Dynamics Simulations ◽  
First Time ◽  
Good Agreement

Multicanonical molecular dynamics simulations are applied, for the first time, to study the liquid-solid and solid-solid transitions in Lennard-Jones (LJ) clusters. The transition temperatures are estimated based on the peak position in the heat capacity versus temperature curve. For LJ31, LJ58 and LJ98, our results on the solid-solid transition temperature are in good agreement with previous ones. For LJ309, the predicted liquid-solid transition temperature is also in agreement with previous result.

Darstellung, Schwingungsspektren und Normalkoordinatenanalyse von Chloro-Bromo-Rhodaten(III) / Preparation, Vibration Spectra and Normal Coordinate Analysis of Chloro-Bromo-Rhodates(III)

1989 ◽  
Vol 44 (10) ◽  
pp. 1221-1227 ◽  
Author(s):  
W. Preetz ◽  
W. Kuhr
Keyword(s):  
Exchange Chromatography ◽  
Trans Isomers ◽  
Normal Coordinate ◽  
Valence Force ◽  
Trans Influence ◽  
Diethylaminoethyl Cellulose ◽  
Point Groups ◽  
First Time ◽  
Ir And Raman ◽  
Good Agreement

The mixed chloro-bromo-rhodates(III) [RhClnBr6-n]3-, n = 1-5, have been separated for the first time by ion exchange chromatography on diethylaminoethyl-cellulose. Due to the stronger trans-effect of Br, as compared with Cl, on treatment of [RhBr6]3- with conc. HCl nearly pure cis/fac-isomers for n = 2, 3, 4 are formed. The reaction of [RhCl6]3- with conc. HBr yields mixtures of the cis/trans-isomers for n = 2, 4, which cannot be separated, but mer-[RhCl3Br3]3 is formed stereospecifically. The IR and Raman spectra of all isolated mixed ligand complexes are completely assigned according to point groups Oh, D3d, C4v, C3v and C2v, supported by normal coordinate analyses based on a general valence force field. The good agreement of calculated and observed frequencies confirms the assignments. Due to the stronger trans-influence of Br as compared to Cl, in all asymmetric Cl—Rh—Br axes the Rh—Br bonds are strengthened and the Rh—Cl bonds are weakened, indicated by valence force constants for Rh—Br approximately 14% higher, for Rh—Cl 10% lower, as compared with the values calculated for symmetric Br—Rh—Br and Cl—Rh—Cl axes, respectively.

Dose-window dependence on Si crystal orientation in separation by implanted oxygen substrate formation

2004 ◽  
Vol 19 (12) ◽  
pp. 3607-3613 ◽  
Author(s):  
H. Iikawa ◽  
M. Nakao ◽  
K. Izumi
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Crystal Orientation ◽  
Oxygen Ion ◽  
The Difference ◽  
First Time ◽  
Good Agreement

Separation by implemented oxygen (SIMOX)(111) substrates have been formed by oxygen-ion (16O+) implantation into Si(111), showing that a so-called “dose-window” at 16O+-implantation into Si differs from Si(100) to Si(111). In SIMOX(100), an oxygen dose of 4 × 1017/cm2 into Si(100) is widely recognized as the dose-window when the acceleration energy is 180 keV. For the first time, our work shows that an oxygen dose of 5 × 1017/cm2 into Si(111) is the dose-window for the formation of SIMOX(111) substrates when the acceleration energy is 180 keV. The difference between dose-windows is caused by anisotropy of the crystal orientation during growth of the faceted buried SiO2. We also numerically analyzed the data at different oxidation velocities for each facet of the polyhedral SiO2 islands. Numerical analysis results show good agreement with the experimental data.

In-Plane Force Effect of Reinforced Concrete Beam with Elastic Supports

2011 ◽  
Vol 287-290 ◽  
pp. 1896-1901
Author(s):  
Zhi Kun Guo ◽  
Wan Xiang Chen ◽  
Qi Fan Wang ◽  
Yu Huang ◽  
Chao Pu Li ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Nonlinear Characteristics ◽  
Elastic Supports ◽  
Calculation Results ◽  
Basic Equations ◽  
First Time ◽  
Good Agreement

The bearing capacities of one-way reinforced concrete beams with elastic supports are investigated in this paper. According to the nonlinear characteristics of the beams, the basic equations based on plastic theory of concrete are derived by considering the in-plane force effects that aroused by the constraints of supports when the beams deforming. It is indicated that the calculation results are in good agreement with experimental datum, and the influences of different supports on the bearing capacities of the beams are quantitatively given for the first time.

Quantum-Confined Optical Interband Transitions in 5-Doped Doping Superlattices

1989 ◽  
Vol 145 ◽  
Author(s):  
E. F. Schubert ◽  
T. D. Harris ◽  
J. E. Cunningham
Keyword(s):  
Emission Spectra ◽  
Doping Profile ◽  
Luminescence Spectra ◽  
Interband Transitions ◽  
Doping Technique ◽  
Quantum Confined ◽  
P Type ◽  
First Time ◽  
Experimental Absorption ◽  
Good Agreement

AbstractOptical absorption and photoluminescence experiments are performed on GaAs doping superlattices, which have a δ-function-like doping profile of alternating n-type and p-type dopant sheets. Absorption and emission spectra reveal for the first time the clear signature of quantum-confined interband transitions. The peaks of the experimental absorption and luminescence spectra are assigned to calculated energies of quantum-confined transitions with very good agreement. It is shown that the employment of the δ-doping technique results in improved optical properties of doping superlattices.

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