scholarly journals The anomalous behavior of liquids in three-dimensional and two-dimensional spaces

2021 ◽  
Vol 13 (2) ◽  
pp. 111-118
Author(s):  
Yury D. Fomin ◽  
◽  
Elena N. Tsiok ◽  
Anton B. Teslyuk ◽  
Valentin N. Ryzhov ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Space Dimension ◽  
Three Dimensional ◽  
Anomalous Behavior ◽  
Two Dimensional ◽  
Step Width ◽  
Density Anomaly ◽  
2D System ◽  
Potential Parameters ◽  
Dynamics Method

Using a molecular dynamics method water-like anomalies in a core-softened system depending on the potential parameters and space dimension were investigated. We have examined the anomalies of density, diffusion and structure and have shown that the sequence of anomalous regions cardinally depends on the repulsive step width and space dimension. Thus, in a three-dimensional (3D) system with small values of the step width the sequence of anomalous regions is the same as in water, whereas in a two-dimensional (2D) system – as in liquid silica. With an increase in the step width, an inversion of the regions of the diffusion anomaly and of the density anomaly is observed. Such an unusual sequence of anomalous regions different from water and liquid silica is exclusively caused by the step width and does not depend on the space dimension.

Viscosity Prediction of Water-Based Silver Nanofluid Using Equilibrium Molecular Dynamics

2016 ◽  
Author(s):  
Qianli Ma ◽  
Haisheng Fang
Keyword(s):  
Molecular Dynamics ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Weight Fraction ◽  
Nanoparticle Concentration ◽  
Nanoparticle Aggregation ◽  
Ink Jet ◽  
Jet Printing ◽  
Viscosity Prediction ◽  
Dynamics Method

Nanofluids containing silver (Ag) nanoparticles have been used in three dimensional ink-jet printing (3DP) in recent years. Rheological properties of the nanofluids, for example, viscosity, play significant roles during the application. In this paper, viscosity of Ag-water nanofluid has been predicted using the equilibrium molecular dynamics method. The influencing factors of the viscosity, including temperature, nanoparticle size, nanoparticle concentration and nanoparticle aggregation, have been investigated. By screening the existing water models, TIP4P/2005 model is found the most suitable for viscosity calculation under the temperature range. The weight fraction of the nanoparticles, which proves more appropriate, is used during the study of the concentration effect instead of volume fraction. The results show that the viscosity of the nanofluid goes up by decreasing temperature or increasing nanoparticle concentration. Furthermore, as the nanoparticles get smaller, or aggregate, the viscosity increases slightly.

Three-dimensional (3D) system versus two-dimensional (2D) system for laparoscopic resection of adrenal tumors: a case-control study

2020 ◽  
Vol 405 (8) ◽  
pp. 1163-1173 ◽  
Author(s):  
José Ignacio Rodríguez-Hermosa ◽  
Alejandro Ranea ◽  
Olga Delisau ◽  
Pere Planellas-Giné ◽  
Lídia Cornejo ◽  
...  
Keyword(s):  
Case Control Study ◽  
Laparoscopic Resection ◽  
Three Dimensional ◽  
Case Control ◽  
Adrenal Tumors ◽  
Two Dimensional ◽  
System Versus ◽  
2D System ◽  
Control Study

Role of divalent cation (Ba) substitution in the Li+ ion conductor LiTi2(PO4)3: a molecular dynamics study

2020 ◽  
Vol 22 (26) ◽  
pp. 14471-14479
Author(s):  
Kartik Sau ◽  
Tamio Ikeshoji ◽  
Supriya Roy
Keyword(s):  
Molecular Dynamics ◽  
Divalent Cation ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Ion Diffusion ◽  
Ion Conductor ◽  
Li Ion ◽  
Ba Substitution

Influence of Ba2+ ordering on cationic diffusion: (a) three-dimensional low Li+ ion diffusion using randomly substituted Ba2+, and (b) two-dimensional layered type high Li+ ion diffusion using specifically ordered substitution of Ba2+.

scholarly journals Effect of Diameter, Length, and Chirality on the Properties of Silicon Nanotubes

2021 ◽  
Author(s):  
Mohsen Motamedi ◽  
Erphan Safdari
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Fracture Stress ◽  
Two Dimensional ◽  
Silicon Nanotubes ◽  
Mechanical And Physical Properties ◽  
Specific Order ◽  
Dynamics Method ◽  
Diameter Change ◽  
Good Agreement

Abstract The mechanical properties of nanostructures are a researcher's favorite topics. In the meantime, the mechanical and physical properties of the two dimensional structures and the nanotubes have attracted greater attention due to their wide application. Si (Si) nanotubes are structures consisting of Si atoms that are aligned as honeycombs (hexagonal). This structure has created some special properties in Si nanotubes. In this paper, Young’s modulus values and stress strain diagrams of Si nanotubes are investigated using molecular dynamics method and the Tersoff potential. Then, the changes effect of size and dimension was investigated for a closer look. For this purpose, the effect of nanotube diameter, length, and chirality shift from zigzag to armchair were studied. The results showed that the fracture stress of nanotube decreased with increasing the length of Si nanotube. It was also shown that the armchair structure was stronger than the zigzag. The effect of diameter change on the mechanical properties was also investigated and it was observed that no specific order could be found between the diameter changes with the Si nanotube strength. The results were in good agreement with other studies.

scholarly journals Десорбция водорода из пентаграфана

2019 ◽  
Vol 53 (5) ◽  
pp. 724
Author(s):  
Л.А. Опенов ◽  
А.И. Подливаев
Keyword(s):  
Molecular Dynamics ◽  
Carbon Nanostructures ◽  
Single Layer ◽  
Hydrogen Desorption ◽  
Phonon Density ◽  
Two Dimensional ◽  
Phonon Density Of States ◽  
Hydrocarbon Compound ◽  
Atomistic Computer Simulation ◽  
Dynamics Method

AbstractThermally activated hydrogen desorption from pentagraphane is studied by atomistic computer simulation. Pentagraphane is a recently predicted quasi-two-dimensional hydrocarbon compound that represents a pentagraphene single layer, in which both sides are covered with hydrogen and the C–C bonds form a network of adjacent pentagons, whereas the hexagons characteristic of carbon nanostructures are lacking. The effect of hydrogen desorption on the electronic structure, phonon density of states, and Young’s modulus are studied. The temperature dependence of the characteristic desorption time is determined by the molecular-dynamics method.

CHAOTIC MOTION OF TWO MOLECULES IN A BOX

1993 ◽  
Vol 03 (05) ◽  
pp. 693-710 ◽  
Author(s):  
M. HASEGAWA ◽  
K. NANBU ◽  
K. IWATA
Keyword(s):  
Molecular Dynamics ◽  
Chaotic Motion ◽  
Three Dimensional ◽  
Physical Space ◽  
Temporal Behavior ◽  
Initial Condition ◽  
Remarkable Feature ◽  
Higher Dimensional ◽  
Physical Spaces ◽  
Dynamics Method

Motion of two molecules in a specularly reflecting box is analyzed for two-, three- and higher-dimensional cases. The temporal behavior of this nonlinear system is pursued by the molecular-dynamics method. The distributions of molecular velocities and collisional points are examined for two- and three-dimensional cases. Strange patterns, which depend on the initial condition of the system, have been found in velocity and physical spaces. The reason of this remarkable feature is discussed. The energy distribution function is also examined for a molecule in chaotic motion. The distribution depends on the dimension of the physical space. It can be described by the beta distribution, which holds in general for any dimension.

The Investigation of Nanowires Properties in the Process of Deformation

2018 ◽  
Vol 30 ◽  
pp. 34-38
Author(s):  
Mikhail D. Starostenkov ◽  
Oleg V. Yashin ◽  
Alexander V. Yashin
Keyword(s):  
Molecular Dynamics ◽  
Crystal Lattice ◽  
Three Dimensional ◽  
Cubic Symmetry ◽  
Pair Potentials ◽  
Deformation Processes ◽  
Three Dimensional Models ◽  
Axial Stretching ◽  
Fcc Metal ◽  
Dynamics Method

In this work, the authors attempted to consider the influence of the geometry of the crystal lattice on the properties of nanowires, which manifest themselves in the process of uni-axial stretching. This work summarizes and systematizes the results of previous studies of the authors. The first group of samples – are typical FCC metal – Ni3Al. For these nanowires, deformation processes in directions with different packing densities of atoms <100>, <110> and <111> were investigated. The second material group studied was an alloy with the non-cubic symmetry of the element cell CuAu I. Correspondingly, this sample was examined under deformation in directions corresponding to different lengths of the sides of the unit cell, <001> and <010>. All the investigations described in this paper were carried out by molecular dynamics method on three-dimensional models using the Morse's pair potentials.

Investigation on the Evolution of the Coal Macromolecule in the Process of Combustion With the Molecular Dynamics Method

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Bonan Xu ◽  
Hanhui Jin ◽  
Hanqing Li ◽  
Yu Guo ◽  
Jianren Fan
Keyword(s):  
Molecular Dynamics ◽  
Chemical Reactions ◽  
Coal Combustion ◽  
Ring Opening ◽  
Combustion Process ◽  
Three Dimensional ◽  
Structural Evolution ◽  
Coal Particles ◽  
Dynamics Method ◽  
Detailed Chemical

Abstract It is reported that a three-dimensional cross-linked macromolecular structure with heterogeneous inorganic and organic compositions widely exists in coal particles. The macromolecules usually represent the rank transition of more than 75% of the carbon (C) content of coal particles. In order to know the coal combustion process better, it is important to specifically study the evolution of the coal macromolecule during combustion. In this paper, the structural evolution and the detailed oxidization reactions of a coal macromolecule during the process of combustion are numerically studied with the reactive force field (ReaxFF) molecular dynamics (MD) method, in which the carbon (C) and hydrogen (H) atoms are fully oxidized to CO2 and H2O, respectively. It is found that the coal macromolecule experiences three main stages sequentially: the cleavage, the ring opening, and the oxidation. The heteroatoms (O, N, and S) inside the coal macromolecule are found to play important roles throughout the whole combustion process. The detailed chemical reactions with their occurrence frequencies show that the chemical reactions with O2 mainly occur in C1–4 fragments, and the C1–2–H–O fragments widely exist in the system before they are finally oxidized to CO or CO2.

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