Elastic Moduli of H2O: Liquid, Ice VI and Ice VII

1983 ◽  
Vol 22 ◽  
Author(s):  
M. Grimsditch ◽  
A. Rahman ◽  
A. Poliant
Keyword(s):  
Molecular Dynamics ◽  
Bulk Modulus ◽  
Room Temperature ◽  
Elastic Moduli ◽  
Brillouin Scattering ◽  
Density Measurements ◽  
Molecular Dynamics Calculations ◽  
Pressure Region ◽  
Scattering Study ◽  
High Pressure Region

ABSTRACTThe results of a Brillouin scattering study of the room temperature phases of H2;O (liquid, ice VI and ice VII) up to 30 GPa are presented. Longitudinal elastic moduli thus obtained are compared with values of the bulk modulus obtained from density measurements [1] and with both static and molecular dynamics calculations of the bulk modulus using potentials which have been proposed in studies of the liquid state. The calculations indicate that the potentials are not capable of describing the high pressure region of ice VII.

scholarly journals Temperature dependence of the elastic moduli of diamond: A Brillouin-scattering study

1998 ◽  
Vol 57 (5) ◽  
pp. 2889-2896 ◽  
Author(s):  
E. S. Zouboulis ◽  
M. Grimsditch ◽  
A. K. Ramdas ◽  
S. Rodriguez
Keyword(s):  
Temperature Dependence ◽  
Elastic Moduli ◽  
Brillouin Scattering ◽  
Scattering Study

Density dependence of the collision-induced light scattering spectral moments of argon

1981 ◽  
Vol 59 (10) ◽  
pp. 1475-1480 ◽  
Author(s):  
M. Zoppi ◽  
F. Barocchi ◽  
D. Varshneya ◽  
M. Neumann ◽  
T. A. Litovitz
Keyword(s):  
Molecular Dynamics ◽  
Light Scattering ◽  
Liquid Phase ◽  
Gas Phase ◽  
Room Temperature ◽  
Polarizability Anisotropy ◽  
Spectral Moments ◽  
Dilute Gas ◽  
Induced Dipole ◽  
Molecular Dynamics Calculations

The zeroth and second moment of the collision induced light scattering in argon have been measured as a function of the density in the gas phase up to 530 amagat at room temperature and in the liquid phase near the triple point. The experimental results have been compared with molecular dynamics calculations in both phases assuming the dipole – induced dipole model and an empirical form for the interaction induced polarizability anisotropy which was previously derived from the dilute gas experiments. The overall agreement between the calculated values of the moments employing the empirical model of anisotropy and the experimental ones is very satisfactory. In particular, the value of considering both the moments for this comparison is pointed out.

scholarly journals Reconciling Experimental and Theoretical Vibrational Deactivation in Low-Energy O+N2 Collisions

2021 ◽  
Author(s):  
Qizhen Hong ◽  
Massimiliano Bartolomei ◽  
Fabrizio Esposito ◽  
Cecilia Coletti ◽  
Quanhua Sun ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Atomic Oxygen ◽  
Room Temperature ◽  
Molecular Nitrogen ◽  
Low Energy ◽  
Inelastic Collisions ◽  
Experimental Results ◽  
Molecular Dynamics Calculations

Molecular dynamics calculations of inelastic collisions of atomic oxygen with molecular nitrogen are known to show orders of magnitude discrepancies with experimental results in the range from room temperature to...

Molecular Dynamics Study of A Model Langmuir-Blodgett Film

1988 ◽  
Vol 141 ◽  
Author(s):  
James P. Bareman ◽  
Gianni Cardini ◽  
Michael L. Klein
Keyword(s):  
Molecular Dynamics ◽  
Room Temperature ◽  
Structural Features ◽  
Head Group ◽  
Angle Distribution ◽  
Blodgett Film ◽  
Langmuir Blodgett ◽  
Planar Substrate ◽  
Molecular Dynamics Calculations ◽  
Langmuir Blodgett Film

AbstractMolecular dynamics calculations have been carried out on a primitive model of a Langmuir-Blodgett film. The model consists of a patch of 151 molecules, each with a head group and a 19 pseudoatom tail, physisorbed on a planar substrate at room temperature. The aggregated patch is found to be a stable entity for the duration of the calculation (200 ps), with structural features similar to those found in previous calculations on a monolayer system which employed periodic boundary conditions but no explicit headgroup. Results are presented for the density distribution normal to the surface, the average chain tilt angle distribution and for the number of gauche defects.

Ultimate H2 and CH4 adsorption in slit-like carbon nanopores at 298 K: a molecular dynamics study

RSC Advances ◽  
2014 ◽  
Vol 4 (44) ◽  
pp. 22848-22855 ◽  
Author(s):  
Eric Poirier
Keyword(s):  
Molecular Dynamics ◽  
Room Temperature ◽  
High Pressures ◽  
Gas Adsorption ◽  
Methane Storage ◽  
Molecular Dynamics Calculations ◽  
Ch4 Adsorption ◽  
Slit Pores ◽  
Very High ◽  
Carbon Slit Pores

Molecular dynamics calculations of gas adsorption in ideal carbon slit pores provide new insights into the physical limits of nanocarbons for hydrogen and methane storage at very high pressures and room temperature.

scholarly journals New Insights into the Structure of Glycols and Derivatives: A Comparative X-Ray Diffraction, Raman and Molecular Dynamics Study of Ethane-1,2-Diol, 2-Methoxyethan-1-ol and 1,2-Dimethoxy Ethane

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1011
Author(s):  
Lorenzo Gontrani ◽  
Pietro Tagliatesta ◽  
Antonio Agresti ◽  
Sara Pescetelli ◽  
Marilena Carbone
Keyword(s):  
Molecular Dynamics ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bond ◽  
Hydroxyl Groups ◽  
Gauche Conformation ◽  
X Ray ◽  
Hydrogen Bond Interactions ◽  
Molecular Dynamics Calculations ◽  
Diffraction Patterns ◽  
Intramolecular Hydrogen

In this study, we report a detailed experimental and theoretical investigation of three glycol derivatives, namely ethane-1,2-diol, 2-methoxyethan-1-ol and 1,2-dimethoxy ethane. For the first time, the X-ray spectra of the latter two liquids was measured at room temperature, and they were compared with the newly measured spectrum of ethane-1,2-diol. The experimental diffraction patterns were interpreted very satisfactorily with molecular dynamics calculations, and suggest that in liquid ethane-1,2-diol most molecules are found in gauche conformation, with intramolecular hydrogen bonds between the two hydroxyl groups. Intramolecular H-bonds are established in the mono-alkylated diol, but the interaction is weaker. The EDXD study also evidences strong intermolecular hydrogen-bond interactions, with short O···O correlations in both systems, while longer methyl-methyl interactions are found in 1,2-dimethoxy ethane. X-ray studies are complemented by micro Raman investigations at room temperature and at 80 °C, that confirm the conformational analysis predicted by X-ray experiments and simulations.

The measurement and interpretation of Brillouin scattering in the lens of the eye

1982 ◽  
Vol 214 (1197) ◽  
pp. 449-470 ◽  
Keyword(s):  
High Frequency ◽  
Reasonable Agreement ◽  
Protein Concentration ◽  
Elastic Moduli ◽  
Brillouin Scattering ◽  
Density Measurements ◽  
Hypersonic Speed ◽  
Fabry Perot ◽  
Lower Protein ◽  
Different Parts

Brillouin scattering from hypersonic waves in the eye lenses of many animals has been observed with a multipass Fabry Perot interferometer. The measured values of speed and attenuation range widely among the different species and in different parts of any one lens. These variations correlate broadly with the observed stiffness and the densities that have been measured with a graded column. From the spectroscopic and density measurements high-frequency elastic moduli may be derived. The results are also evaluated at a macromolecular level in terms of scattering of hypersonic waves from spherical entities composed of the crystallins and their aggregates. Reasonable agreement is obtained for the hypersonic speed for lower protein concentration; the hypersonic attenuation and variation with scattering vector are consistent with the presence of large aggregates (of order 100 nm radius) in certain of the materials.

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