scholarly journals Shear dynamics of confined membranes

Soft Matter ◽  
2021 ◽  
Author(s):  
Thomas Le Goff ◽  
Tung B.T. To ◽  
Olivier Pierre-Louis
Keyword(s):  
Nonlinear Response ◽  
Lipid Membrane ◽  
Two Dimensional ◽  
Simple Fluid ◽  
Porous Walls ◽  
Lubricated Contact

We model the nonlinear response of a lubricated contact composed of a two-dimensional lipid membrane immersed in a simple fluid between two parallel flat and porous walls under shear. The...

scholarly journals Effective Generation of Milliwatt-Level Sub-Terahertz Wave for Nonlinear Response Measurement of Two-Dimensional Material by Optical Heterodyne Technique

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Shuqing Chen ◽  
Zhiqiang Xie ◽  
Junmin Liu ◽  
Yanliang He ◽  
Yao Cai ◽  
...  
Keyword(s):  
Nonlinear Response ◽  
Modulation Depth ◽  
Terahertz Wave ◽  
Saturable Absorption ◽  
Optical Heterodyne ◽  
Two Dimensional ◽  
Response Measurement ◽  
Microwave Source ◽  
Terahertz Band ◽  
Heterodyne Technique

By using optical heterodyne technique, we demonstrated the stable emission of sub-terahertz wave with the frequency ranging from 88 GHz to 101 GHz, which can operate as microwave source for nonlinear response measurement system. Mutual frequency beating of two well-separated sideband signals at a 0.1 THz photo-detector (PD) allows for the generation of sub-terahertz signal. Based on this approach, we have achieved the radiation of 0.1 THz wave with power up to 4 mW. By transmittance measurement, two-dimensional nanomaterial topological insulator (TI: Bi2Te3) shows saturable absorption behaviors with normalized modulation depth of 47% at 0.1 THz. Our results show that optical heterodyne technique could be developed as an effective microwave source generation for nonlinear measurement at sub-terahertz, even terahertz band.

TWO-DIMENSIONAL NONLINEAR OPTICS SPECTROSCOPY: SIMULATIONS AND EXPERIMENTAL DEMONSTRATION

1996 ◽  
Vol 05 (03) ◽  
pp. 465-476 ◽  
Author(s):  
L. LEPETIT ◽  
G. CHÉRIAUX ◽  
M. JOFFRE
Keyword(s):  
Fourier Transform ◽  
Nonlinear Response ◽  
Two Dimensions ◽  
Second Order ◽  
Phase Matching ◽  
Two Dimensional ◽  
Experimental Demonstration ◽  
Spectral Interferometry ◽  
Dimensional Measurement ◽  
A New Technique

We propose a new technique, using femtosecond Fourier-transform spectral interferometry, to measure the second-order nonlinear response of a material in two dimensions of frequency. We show numerically the specific and unique information obtained from such a two-dimensional measurement. The technique is demonstrated by measuring the second-order phase-matching map of two non-resonant nonlinear crystals.

scholarly journals Nonlinear response of vibrational excitons: Simulating the two-dimensional infrared spectrum of liquid water

2009 ◽  
Vol 130 (20) ◽  
pp. 204110 ◽  
Author(s):  
A. Paarmann ◽  
T. Hayashi ◽  
S. Mukamel ◽  
R. J. D. Miller
Keyword(s):  
Infrared Spectrum ◽  
Liquid Water ◽  
Nonlinear Response ◽  
Two Dimensional

Computational Study on Second-Order Nonlinear Response of a Series of Two-Dimensional Carbazole-Cored Chromophores

2008 ◽  
Vol 112 (17) ◽  
pp. 7021-7028 ◽  
Author(s):  
Chun-Guang Liu ◽  
Yong-Qing Qiu ◽  
Zhong-Min Su ◽  
Guo-Chun Yang ◽  
Shi-Ling Sun
Keyword(s):  
Nonlinear Response ◽  
Computational Study ◽  
Second Order ◽  
Two Dimensional

Numerical Simulation of Heat, Air, and Moisture Transfer Through a Wall of Porous Media

2020 ◽  
Author(s):  
Kiflom B. Tesfamariam ◽  
Cheng-Xian (Charlie) Lin ◽  
Fang Liu
Keyword(s):  
Numerical Simulation ◽  
Moisture Transport ◽  
Moisture Transfer ◽  
Simulation Software ◽  
Transport Processes ◽  
Two Dimensional ◽  
Heat And Moisture Transfer ◽  
Porous Walls ◽  
Heat And Moisture ◽  
Benchmark Solutions

Abstract This paper presents the results of two-dimensional (2D) numerical simulation of heat, air, and moisture transfer through porous walls, which have important application background in the built environment and other engineering fields. The air flows, heat and moisture transfer in the walls are studied using a transient heat, air, and moisture (HAM) model. This model treats the non-isothermal airflow through two-dimensional porous geometries in a time-dependent format. The model includes the Brinkman equation describes the flow of air and other mathematical equations that calculate the heat and moisture transfer through the porous region. The equations are solved by a finite element method (FEM) using physics-based modeling, which is implemented in the commercial simulation software, COMSOL Multiphysics. The model prediction is first validated by using published benchmark solutions. Eventually, the numerical results are presented to illustrate the complex effects of material porosity and permeability on the heat and moisture transport, and moisture content variation in space and time through the walls, at different humidity and temperature conditions. Within the investigated parameter ranges, it is demonstrated that the relative humidity and temperature difference are the driving forces for the transient heat, air, and moisture transport processes through the porous area in the porous walls.

An Investigation of the Aeroelastic Response of a Two-Dimensional, Structurally Nonlinear Airfoil Subject to External Excitation

2002 ◽  
Author(s):  
Catharine C. Marsden ◽  
Stuart J. Price
Keyword(s):  
Fourier Transform ◽  
Frequency Domain ◽  
Nonlinear Response ◽  
Transfer Functions ◽  
Time History ◽  
System Response ◽  
Two Dimensional ◽  
Aeroelastic System ◽  
Aeroelastic Response ◽  
Band Limited

The results of an analytical investigation are presented for the aeroelastic response of a two-dimensional, structurally nonlinear airfoil subject to a forced excitation. The system is modeled as a two-dimensional, rigid airfoil section free to move in both the bending and pitching directions and possessing a rigid flap. The airfoil is mounted by torsional and translational springs attached at the elastic axis, and the flap motion is used to provide the forcing input to the system. The airfoil is immersed in an aerodynamic flow environment, modeled using incompressible thin airfoil theory for unsteady oscillatory motion. The equations of motion for the aeroelastic system are solved using a fourth-order Runge-Kutta numerical integration technique to provide time-history solutions of the response of the airfoil in the pitch and plunge directions. The time-histories are analysed using Fourier transform-based techniques to obtain frequency-domain response and transfer functions. Results show that the nonlinear response of the aeroelastic system contains frequencies other than the forcing frequency. When modal frequencies and damping values are calculated using standard Fourier-based techniques, it is shown that the super- and sub-harmonic frequency content in the nonlinear response can contribute to errors when results are compared to those obtained for the equivalent linear system. This paper describes an investigation of a method of analysis that, while based on the Fourier transform, has been modified to recognize and accommodate the nonlinear contribution to the system response. The method, developed by Bendat [1], uses a band-limited random input and separates the linear and nonlinear components of the response within the frequency domain. Results are given for the application of this method to the specific case of the structurally nonlinear aeroelastic system. It is shown that the method may be used to successfully recover the linear frequency response function using the input and output data for the nonlinear system.

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