scholarly journals COMPUTER SIMULATION OF THE POROUS STRUCTURE OF HYDROLYSIS LIGNIN AND ITS HARD COMPO-SITES WITH COMPONENTS OF OIL FUELS AND WATER

2019 ◽  
pp. 73-84
Author(s):  
Татьяна (Tat'yana) Александровна (Aleksandrovna) Савицкая (Savitskaya) ◽  
Иван (Ivan) Вадимович (Vadimovich) Резников (Reznikov) ◽  
Дмитрий (Dmitriy) Давидович (Davidovich) Гриншпан (Grinshpan)
Keyword(s):  
Pore Structure ◽  
Global Minimum ◽  
Dipole Interaction ◽  
Geometric Optimization ◽  
Alcohol Molecule ◽  
Hydrolysis Lignin ◽  
Organic Substances ◽  
Sorption Activity ◽  
Structural Units ◽  
Dynamics Method

A fragment of the supramolecular structure of lignin was simulated by cross-linking the C546H600O196 structural units along the corresponding CH–bonds followed by geometric optimization by the Polac-Ribier’s conjugate gradient method in the MNDO field of the HyperChem 8.0 software and ChemBio 13.0. The pore structure of lignin was simulated as well with optimization by the molecular mechanic’s method according to the MM2 Norman-Alinger’s algorithm taking into account the dipole-dipole interaction. Сoumaric alcohol molecule was a building block. The calculation of the energy parameters of lignin’s pore structure filling by the molecules of organic substances and water were carried out. It included a search for a global minimum of the potential energy by the molecular mechanic’s method according to the MM2 program and by the molecular dynamics method. The calculation had its basis in the “closed” pores existence in lignin. The calculated values of pore volume and specific surface area correlate with the experimental data. The way of prediction of organic substances sorption activity to lignin was proposed. This is evident from their calculated hydrophobicity parameter that correlates with the interaction energy of the molecules in the lignin pore.

Geometries, stabilities and fragmental channels of neutral and charged sulfur clusters: SnQ(n = 3–20, Q = 0, ±1)

2015 ◽  
Vol 17 (20) ◽  
pp. 13590-13597 ◽  
Author(s):  
Yuanyuan Jin ◽  
George Maroulis ◽  
Xiaoyu Kuang ◽  
Liping Ding ◽  
Cheng Lu ◽  
...  
Keyword(s):  
Global Minimum ◽  
Geometric Optimization

We have performed unbiased searches for the global minimum structures of neutral and charged sulfur clusters relying on the CALYPSO method combined with DFT geometric optimization.

scholarly journals Bildung von van der Waals-Komplexen organischer Moleküle

1972 ◽  
Vol 27 (1) ◽  
pp. 162-168 ◽  
Author(s):  
Hans Knof ◽  
Volker Hausen ◽  
Dieter Krafft
Keyword(s):  
Gas Phase ◽  
Quantitative Measurement ◽  
Secondary Electron ◽  
Electron Attachment ◽  
Dipole Interaction ◽  
Ion Source ◽  
Organic Substances ◽  
Electron Multiplier ◽  
Secondary Electron Multiplier ◽  
Electron Pulses

Abstract An electron attachment ion source was modified in order to be used for quantitative measurement of pure organic substances at pressures up to 1.5 ·10-3 Torr in the space around the ion source. The ion intensity was determined by counting the electron pulses produced by single ions in the secondary electron multiplier. This resulted in higher sensitivities. The measurements of different organic compounds showed that molecular polymers are held together primarily by hydro-gen bonding and by dipole interaction. No molecular polymers could be identified in nonpolar substances. The pressure dependence of the ion intensities indicates that the molecular polymers originate from the gas phase of the reservoir. During the ionization process the hydroxide loses its hydrogen atom as was shown with deuterated samples.

scholarly journals Study on the Influence of Factors on the Structure and Mechanical Properties of Amorphous Aluminium by Molecular Dynamics Method

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Tuan Tran Quoc ◽  
Dung Nguyen Trong ◽  
Ştefan Ţălu
Keyword(s):  
Phase Transition ◽  
Mechanical Property ◽  
Molecular Dynamics ◽  
Distribution Function ◽  
Transition Temperature ◽  
Total Energy ◽  
Radial Distribution Function ◽  
Phase Transition Temperature ◽  
Structural Units ◽  
Dynamics Method

The influence of the number of atoms, N = 3000, 5000, 7000, and 9000 atoms, at temperature T = 300 K and temperatures T = 300, 500, 700, 900, 1100, 1300, and 1500 K at N = 9000 atoms, on microscopic structure, phase transition temperature, and mechanical property of bulk aluminium in an amorphous state is studied by the molecular dynamics method with the Sutton–Chen embedded interaction potential and the periodic boundary condition. Structural results are analyzed through the radial distribution function, the total energy of the system, the size, and the common neighbor analysis. The phase transition temperature is determined by the relationship between the total energy of the system and temperature. The mechanical property is derived from the deformation along the Z-axis. It can be noted that when the number of atoms increases, the first peak’s position for radial distribution function changes, the first peak’s height decreases, the number of FCC and HCP structural units decreases, the number of Amor structural units increases, and the total energy of system increases. It can be seen that when temperature increases, the first peak’s position changes, the first peak’s height decreases, the number of FCC and HCP structural units decreases, the number of Amor structural units increases, and the total energy of the system decreases. The obtained results are very useful for experimental studies in the future.

STUDY OF SORBENT OBR -1 CHARACTERISTIC FOR TERTIARY TREATMENT OF DRINKING WATER FROM HEAVY METAL IONS AND ORGANIC SUBSTANCES

2013 ◽  
Vol 3 (1) ◽  
pp. 46-50
Author(s):  
G. B ABUOVA ◽  
L. V BORONINA ◽  
V. I KIChIGIN
Keyword(s):  
Quantum Chemical ◽  
Heavy Metal Ions ◽  
Chemical Method ◽  
Theoretical Study ◽  
Organic Substances ◽  
Tertiary Treatment ◽  
Structural Units ◽  
High Sorption Capacity ◽  
Water Ph ◽  
High Sorption

High sorption capacity of OBR-1 in relation to the studied substances is determined. It is shown that the desorption (elution) of the studied organic and nonorganic compounds from OBR-1 doesnt practically occur in conditions of getting treated water (pH, temperature, concentration). The article describes the theoretical study of organic and nonorganic compounds at particular structural units of OBR-1 using the up-to-date quantum-chemical method that makes it possible to represent the experiment and theorybased models of adsorption units.

scholarly journals Molecular Dynamics Study the Factors Effecting the Structure of MgSiO3 Bulk

2019 ◽  
Vol 8 (2) ◽  
pp. 10
Author(s):  
Dung Nguyen Trong ◽  
Huy Nguyen Quoc
Keyword(s):  
Molecular Dynamics ◽  
Distribution Function ◽  
Boundary Conditions ◽  
Radial Distribution Function ◽  
Coordination Number ◽  
Periodic Boundary ◽  
Periodic Boundary Conditions ◽  
Angle Distribution ◽  
Structural Units ◽  
Dynamics Method

This paper studies the effect of atomic numbers (N), N=2000atoms, 3000atoms, 4000atoms, 5000atoms, 6000atoms at temperature (T), T=300K; N=5000atoms at T=300K, 500K, 1000K, 1500K, 2000K, 2500K, 3000K, 3500K; N=5000atoms at T=300K, 2000K with pressure (P), P=0GPa, 20GPa, 40GPa, 60GPa, 80GPa, 100GPa on the structure of MgSiO3 bulk by Molecular Dynamics method (MD) with Born-Mayer potential (BM), periodic boundary conditions. The results were analyzed through the radial distribution function (RDF), coordination number, angle distribution, size (l), energy (E). The results showed that there are the effects of factors on the structure of MgSiO3 bulk. In addition, with the atomic number (N), temperature (T), different pressures (P) at temperature T=300K, 2000K there are the appearance and disappearance of links Si-Si, Si-O, O-O, Si-Mg, O-Mg, Mg-Mg and number of structural units SiO4, SiO5, SiO6, MgO3, MgO4, MgO5, MgO6, MgO7, MgO8, MgO9 , MgO10, MgO11, MgO12

scholarly journals Immersion Heats of Active Carbons in Water and Organic Substances

1993 ◽  
Vol 10 (1-4) ◽  
pp. 27-33 ◽  
Author(s):  
M.L. Goubkina ◽  
N.S. Polyakov ◽  
L.I. Tatarinova
Keyword(s):  
Pore Structure ◽  
Size Distribution ◽  
Active Carbon ◽  
Heat Balance ◽  
Molecular Sieve ◽  
Organic Substances ◽  
Active Carbons ◽  
Structure Characteristics ◽  
Sieve Effect ◽  
The Heat Balance

The immersion heats of two active carbon (AC) samples in water and organic substances with molecules of different size have been investigated. A molecular sieve effect was established. It has been shown that changes in the immersion heats of the active carbons correspond to pore structure characteristics such as the size distribution of the micropores. The immersion heats of moistened active carbons in liquids have also been investigated, and the heat balance of the process calculated.

Correlation of Pore Structure and Permeability by SEM-Image Analysis

1990 ◽  
Vol 48 (1) ◽  
pp. 428-429
Author(s):  
C. A. Callender ◽  
Wm. C. Dawson ◽  
J. J. Funk
Keyword(s):  
Image Analysis ◽  
Pore Structure ◽  
Imaging System ◽  
Pore Space ◽  
Simulation Models ◽  
Image Analyzer ◽  
Imaging Data ◽  
Sem Images ◽  
Thin Sections ◽  
Rock Types

The geometric structure of pore space in some carbonate rocks can be correlated with petrophysical measurements by quantitatively analyzing binaries generated from SEM images. Reservoirs with similar porosities can have markedly different permeabilities. Image analysis identifies which characteristics of a rock are responsible for the permeability differences. Imaging data can explain unusual fluid flow patterns which, in turn, can improve production simulation models.Analytical SchemeOur sample suite consists of 30 Middle East carbonates having porosities ranging from 21 to 28% and permeabilities from 92 to 2153 md. Engineering tests reveal the lack of a consistent (predictable) relationship between porosity and permeability (Fig. 1). Finely polished thin sections were studied petrographically to determine rock texture. The studied thin sections represent four petrographically distinct carbonate rock types ranging from compacted, poorly-sorted, dolomitized, intraclastic grainstones to well-sorted, foraminiferal,ooid, peloidal grainstones. The samples were analyzed for pore structure by a Tracor Northern 5500 IPP 5B/80 image analyzer and a 80386 microprocessor-based imaging system. Between 30 and 50 SEM-generated backscattered electron images (frames) were collected per thin section. Binaries were created from the gray level that represents the pore space. Calculated values were averaged and the data analyzed to determine which geological pore structure characteristics actually affect permeability.

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