scholarly journals Symmetric and Anti-Symmetric Damping Modes of Trivelpiece–Gould Waves in Weakly and Completely Ionized Plasma Waveguides

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 699
Author(s):  
Myoung-Jae Lee ◽  
Young-Dae Jung
Keyword(s):  
Normal Mode Analysis ◽  
Low Frequency ◽  
Mode Analysis ◽  
Harmonic Mode ◽  
Absolute Value ◽  
Plasma Waveguides ◽  
Damping Rate ◽  
Weakly Ionized ◽  
Weakly Ionized Plasma ◽  
Opposite Tendency

The collision effects on the low-frequency ion-acoustic Trivelpiece–Gould wave are investigated in weakly and completely ionized plasma waveguides by using the normal mode analysis. In weakly ionized plasma waveguides, it is found that the dependence of the harmonic mode on the absolute value of the scaled damping rate shows the opposite tendency for large and small radii of the cylindrical waveguide. It is also is found that the scaled damping rates for both weakly and completely ionized plasma waveguides decrease with an increase of the electron temperature. It is interesting to note that the scaled damping rate for weakly ionized plasma waveguides shows anti-symmetric behavior when the Trivelpiece–Gould wave propagates in the negative-z direction. However, it is found that the scaled damping rate for completely ionized plasma waveguides shows the symmetric behavior when the Trivelpiece–Gould wave propagates in the negative-z direction.

THZ-FREQUENCY SPECTROSCOPIC SENSING OF DNA AND RELATED BIOLOGICAL MATERIALS

2003 ◽  
Vol 13 (04) ◽  
pp. 903-936 ◽  
Author(s):  
T. GLOBUS ◽  
D. WOOLARD ◽  
M. BYKHOVSKAIA ◽  
B. GELMONT ◽  
L. WERBOS ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Normal Mode ◽  
Normal Mode Analysis ◽  
Low Frequency ◽  
Biological Materials ◽  
Mode Analysis ◽  
Resonance Structure ◽  
Terahertz Frequency ◽  
Dna Molecules ◽  
Phonon Modes

The terahertz frequency absorption spectra of DNA molecules reflect low-frequency internal helical vibrations involving rigidly bound subgroups that are connected by the weakest bonds, including the hydrogen bonds of the DNA base pairs, and/or non-bonded interactions. Although numerous difficulties make the direct identification of terahertz phonon modes in biological materials very challenging, recent studies have shown that such measurements are both possible and useful. Spectra of different DNA samples reveal a large number of modes and a reasonable level of sequence-specific uniqueness. This chapter utilizes computational methods for normal mode analysis and theoretical spectroscopy to predict the low-frequency vibrational absorption spectra of short artificial DNA and RNA. Here the experimental technique is described in detail, including the procedure for sample preparation. Careful attention was paid to the possibility of interference or etalon effects in the samples, and phenomena were clearly differentiated from the actual phonon modes. The results from Fourier-transform infrared spectroscopy of DNA macromolecules and related biological materials in the terahertz frequency range are presented. In addition, a strong anisotropy of terahertz characteristics is demonstrated. Detailed tests of the ability of normal mode analysis to reproduce RNA vibrational spectra are also conducted. A direct comparison demonstrates a correlation between calculated and experimentally observed spectra of the RNA polymers, thus confirming that the fundamental physical nature of the observed resonance structure is caused by the internal vibration modes in the macromolecules. Application of artificial neural network analysis for recognition and discrimination between different DNA molecules is discussed.

Low Frequency Raman Spectra in Water by Normal Mode Analysis

1994 ◽  
pp. 197-203
Author(s):  
Srikanth Sastry ◽  
H. Eugene Stanley ◽  
Francesco Sciortino
Keyword(s):  
Raman Spectra ◽  
Normal Mode ◽  
Normal Mode Analysis ◽  
Low Frequency ◽  
Mode Analysis

A minimal coarse-grained model for the low-frequency normal mode analysis of icosahedral viral capsids

Soft Matter ◽  
2020 ◽  
Vol 16 (14) ◽  
pp. 3443-3455 ◽  
Author(s):  
M. Martín-Bravo ◽  
J. M. Gomez Llorente ◽  
J. Hernández-Rojas
Keyword(s):  
Structural Properties ◽  
Normal Mode ◽  
Normal Mode Analysis ◽  
Low Frequency ◽  
Coarse Grained ◽  
Mode Analysis ◽  
Viral Capsids ◽  
Mode Spectrum ◽  
Coarse Grained Model

A minimal coarse-grained model unveils relevant structural properties of icosahedral viral capsids when fitted to reproduce their low-frequency normal-mode spectrum.

Low frequency depolarized Raman spectra in water: Results from normal mode analysis

1994 ◽  
Vol 100 (7) ◽  
pp. 5361-5366 ◽  
Author(s):  
Srikanth Sastry ◽  
H. Eugene Stanley ◽  
Francesco Sciortino
Keyword(s):  
Raman Spectra ◽  
Normal Mode ◽  
Normal Mode Analysis ◽  
Low Frequency ◽  
Mode Analysis

scholarly journals A minimalist network model for coarse-grained normal mode analysis and its application to biomolecular x-ray crystallography

2008 ◽  
Vol 105 (40) ◽  
pp. 15358-15363 ◽  
Author(s):  
Mingyang Lu ◽  
Jianpeng Ma
Keyword(s):  
Normal Mode ◽  
Network Model ◽  
Normal Mode Analysis ◽  
Low Frequency ◽  
Coarse Grained ◽  
Mode Analysis ◽  
Conformational Sampling ◽  
Structural Refinement ◽  
X Ray ◽  
X Ray Crystallography

In this article, we report a method for coarse-grained normal mode analysis called the minimalist network model. The main features of the method are that it can deliver accurate low-frequency modes on structures without undergoing initial energy minimization and that it also retains the details of molecular interactions. The method does not require any additional adjustable parameters after coarse graining and is computationally very fast. Tests on modeling the experimentally measured anisotropic displacement parameters in biomolecular x-ray crystallography demonstrate that the method can consistently perform better than other commonly used methods including our own one. We expect this method to be effective for applications such as structural refinement and conformational sampling.

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