Vibration attenuation analysis of compressional gas cushion press nanoimprint lithography system

2013 ◽  
Vol 228 (9) ◽  
pp. 1634-1642 ◽  
Author(s):  
Liu Chaoran ◽  
Yue Jinzhao ◽  
Li Tianhao ◽  
Xia Weiwei ◽  
Li Dongxue ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Theoretical Models ◽  
Physical Parameters ◽  
Attenuation Effect ◽  
Internal Structures ◽  
Vibration Attenuation ◽  
System Vibration ◽  
Novel Method ◽  
Lithography System ◽  
Great Development

Nanoimprint lithography has a great development in decades. Compressional gas cushion press is a novel method in improving the uniformity in nanoimprint lithography process. Based on compressional gas cushion press nanoimprint lithography system, an attenuation ring is added between the chamber wall and the pedestal. The attenuation ring decreases the influence of system vibration on the fidelity of patterning. The physical parameters of the attenuation material are optimized based on the theoretical models of the vibration attenuation and mechanical calculation. According to the optimization physical parameters, Young's modulus of a perfect material of attenuation ring should be smaller than 8 MPa, and Poisson's ratio should be close to 0.5. Therefore, natural rubber is employed as the material of attenuation ring. The simulation results based on COMSOL indicate that nested rectangular structure has the best attenuation effect among the four simulated internal structures. It provides technological supporting for the establishment of attenuation ring in compressional gas cushion press nanoimprint lithography system.

Flexible devices fabricated by a plate-to-roll nanoimprint lithography system

2018 ◽  
Vol 30 (7) ◽  
pp. 075301 ◽  
Author(s):  
Kai Xu ◽  
Huiwen Luo ◽  
Jin Qin ◽  
Muyi Yang ◽  
Songpo Guo ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Flexible Devices ◽  
Lithography System

scholarly journals Feature of Echo Envelope Fluctuation and Its Application in the Discrimination of Underwater Real Echo and Synthetic Echo

2018 ◽  
Vol 8 (8) ◽  
pp. 1329
Author(s):  
Yunfei Chen ◽  
Sheng Li ◽  
Bing Jia ◽  
Guijuan Li ◽  
Zhenshan Wang
Keyword(s):  
Physical Parameters ◽  
Scaled Model ◽  
Theoretical Simulation ◽  
Active Sonar ◽  
Fluctuation Intensity ◽  
Characterization Model ◽  
Novel Method ◽  
Underwater Target ◽  
Echo Features ◽  
Synthetic Target

Discriminating a real underwater target echo from a synthetic echo is a key challenge to identifying an underwater target. The structure of an echo envelope contains information which closely relates to the physical parameters of the underwater target, and the characterization and extraction of echo features are problematic issues for active sonar target classification. In this study, firstly, the high-frequency envelope fluctuation of a complex underwater target echo was analyzed, the envelope fluctuation was characterized by the envelope fluctuation intensity, and a characterization model was established. The features of a benchmark model echo were extracted and analyzed by theoretical simulation and sea testing of a scaled model, and the result shows that the envelope fluctuation intensity varies with carrier frequency and azimuth of incident signal, but the echo envelope fluctuation of the synthetic target echo does not present these features. Then, based on the characteristics of echo envelope fluctuation, a novel method was developed for active sonar discrimination of a real underwater target echo from the synthetic echo. Through a sea experiment, the real target echo and synthetic echo were classified by their different echo envelope fluctuations, and the feasibility of the method was verified.

scholarly journals A Novel Method to Reduce the Laser Drilling Time for Hole Cluster considering the Influence of Residual Vibration of the Sample Stage

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaodong Wang ◽  
Bin Liu ◽  
Xuesong Mei ◽  
Jun Yang ◽  
Xialun Yun ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Delay Time ◽  
Laser Drilling ◽  
Residual Vibration ◽  
Processing Efficiency ◽  
Common Solution ◽  
Vibration Attenuation ◽  
Novel Method ◽  
Point To Point ◽  
Drilling Time

In large areas of laser drilling, the residual vibration occurs when the sample stage moves in PTP (Point to Point) movement. It affects the surface quality and processing efficiency of the holes. The common solution for this problem is to set the laser irradiation delay time by the controller to wait for the residual vibration attenuation, but the whole drilling circle will increase. In this paper, a new method is introduced to reduce the laser drilling circle. By setting the allowable threshold of the residual vibration for the subsequent process, the sum of the time in deceleration segment of the trapezoidal moving profile, and the time when the residual vibration attenuates below the amplitude threshold (ST) can be minimized as the optimization goal. The results show that for a given operating speed, there is always an optimum acceleration value for the deceleration segment of the trapezoidal moving profile, which minimizes the ST value. Further, the delay time for laser irradiation can also be estimated according to the optimal acceleration during laser drilling.

Computational design of resonant phononic crystal for aperiodic stress wave attenuation

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chengcheng Luo ◽  
Shaowu Ning ◽  
Zhanli Liu ◽  
Xiang Li ◽  
Zhuo Zhuang
Keyword(s):  
Stress Wave ◽  
Wave Attenuation ◽  
Design Method ◽  
Phononic Crystal ◽  
Hard Core ◽  
Stress Waves ◽  
Physical Parameters ◽  
Attenuation Effect ◽  
Content Type ◽  
Soft Matrix

Purpose This paper aims to propose a design method for attenuating stress waves pressure using soft matrix embedded with particles. Design/methodology/approach Based on the phononic crystal theory, the particle composed of hard core and soft coating can form a spring oscillator structure. When the frequency of the wave is close to the resonance frequency of the spring oscillator, it can cause the resonance of the particle and absorb a lot of energy. In this paper, the resonant phononic crystal with three phases, namely, matrix, particle core and coating, is computationally designed to effectively mitigate the stress wave with aperiodic waveform. Findings The relationship between the center frequency and width of the bandgap and the geometric and physical parameters of particle core are discussed in detail, and the trend of influence is analyzed and explained by a spring oscillator model. Increasing the radius of hard core could effectively enhance the bandgap width, thus enhancing the effect of stress wave attenuation. In addition, it is found that when the wave is in the bandgap, adding viscosity into the matrix will not further enhance the stress attenuation effect, but will make the stress attenuation effect of the material worse because of the competition between viscous dissipation mechanism and resonance mechanism. Research limitations/implications This study will provide a reference for the design of stress wave protection materials with general stress waves. Originality/value This study proposes a design method for attenuating stress waves pressure using soft matrix embedded with particles.

scholarly journals Ground-Based Optical Observations of Asteroids

2005 ◽  
Vol 13 ◽  
pp. 752-757 ◽  
Author(s):  
Alberto Cellino
Keyword(s):  
Binary Systems ◽  
Optical Observations ◽  
Physical Parameters ◽  
Internal Structures ◽  
Remote Measurements ◽  
Optical Wavelengths ◽  
Spin Properties ◽  
Remote Sensing Techniques ◽  
Near Earth Objects

AbstractMany physical parameters of asteroids can be inferred from remote measurements at optical wavelengths. These observations constitute the bulk of the information we have about these objects, and nicely complement the detailed physical studies which are made possible by in situ explorations of a few selected targets. The discovery of many binary systems for which mass determinations become possible, the identification of hydration features in asteroid spectra, including unexpectedly many M-types, the detection of space-weathering phenomena affecting S-type near-Earth objects, as well as improved estimates of sizes, albedos, and spin properties for many objects are among the major results obtained in recent years by means of remote-sensing techniques. These data can be used to infer important properties of the internal structures of the asteroids.

scholarly journals Towards Identification of Optimum Radar Parameters for Sea-Ice Monitoring

1985 ◽  
Vol 31 (109) ◽  
pp. 214-219
Author(s):  
Y. S. Kim ◽  
R. K. Moore ◽  
R. G. Onstott ◽  
S. Gogineni
Keyword(s):  
Sea Ice ◽  
Field Experiments ◽  
Theoretical Models ◽  
First Year ◽  
Physical Parameters ◽  
Backscattering Coefficient ◽  
Air Bubble ◽  
X Band ◽  
Experimental Findings ◽  
Range Of Values

AbstractVarious field experiments have shown that microwave radars can be used to distinguish multi-year from first-year ice, although optimum radar parameters are not yet fully defined.This paper presents the results from two theoretical models that, using selected physical parameters of sea ice, are able to predict the backscattering from multi-year and first-year ice under cold conditions. The possible ranges of the backscattering coefficient under various conditions (surface roughness, salinity, temperature, density, and air-bubble size) are calculated for multi-year and first-year ice by adjusting the parameters within the reported range of values.Although the calculations show no specific resonance that would favor any particular frequency or incidence angles, the results confirm the experimental findings that Ku- and X-band frequencies, and incidence angles greater than 30°, are better for distinguishing sea-ice types than lower frequencies.

Lattice Boltzmann Simulations for Thermal Conductivity Estimation in Heterogeneous Materials

2009 ◽  
Vol 283-286 ◽  
pp. 364-369 ◽  
Author(s):  
M.R. Arab ◽  
Bernard Pateyron ◽  
Mohammed El Ganaoui ◽  
Nicolas Calvé
Keyword(s):  
Thermal Conductivity ◽  
Porous Medium ◽  
Lattice Boltzmann ◽  
Numerical Study ◽  
Theoretical Models ◽  
Short Description ◽  
Physical Parameters ◽  
Two Dimensional ◽  
Lattice Boltzmann Simulations ◽  
Boltzmann Method

For simulating flows in a porous medium, a numerical tool based on the Lattice Boltzmann Method (LBM) is developed with regards to the classical D2Q9 model. A short description of this model is presented. This technique, applied to two-dimensional configurations, indicates its ability to simulate phenomena of heat and mass transfer. The numerical study is extended to estimate physical parameters that characterize porous materials, like the so-called Effective Thermal Conductivity (ETC) which is of our interest in this paper. Obtained results are compared with those which could be found analytically and by theoretical models. Finally, a porous medium is considered to find its ETC.

scholarly journals A 2.5D APPROACH TO SKIN WRINKLES SEGMENTATION

2019 ◽  
Vol 38 (1) ◽  
pp. 75 ◽  
Author(s):  
Etienne Decencière ◽  
Amira Belhedi ◽  
Serge Koudoro ◽  
Frédéric Flament ◽  
Ghislain François ◽  
...  
Keyword(s):  
Point Clouds ◽  
Skin Surface ◽  
Fringe Projection ◽  
Physical Parameters ◽  
Projection System ◽  
Beneficial Effects ◽  
3D Point Clouds ◽  
Novel Method ◽  
Skin Wrinkles ◽  
Skin Wrinkling

Wrinkles or creases are common structures on surfaces. Their detection is often challenging, and can be an important step for many different applications. For instance, skin wrinkle segmentation is a crucial step for quantifying changes in skin wrinkling and assessing the beneficial effects of dermatological and cosmetic anti-ageing treatments. A 2.5D approach is proposed in this paper to segment individual wrinkles on facial skin surface described by 3D point clouds. The method, based on mathematical morphology, only needs a few physical parameters as input, namely the maximum wrinkle width, the minimum wrinkle length, and the minimum wrinkle depth. It has been applied to data acquired from eye wrinkles using a fringe projection system. An accurate evaluation was made possible thanks to manual annotations provided by three different experts. Results demonstrate the accuracy of this novel method.

scholarly journals Improved modelling for spatially resolved spectroscopy of a P Cyg envelope

1994 ◽  
Vol 162 ◽  
pp. 502-504
Author(s):  
M. Bourguine ◽  
A. Chalabaev
Keyword(s):  
Angular Resolution ◽  
Theoretical Models ◽  
Progress Report ◽  
High Angular Resolution ◽  
Physical Parameters ◽  
Base Length ◽  
Spatially Resolved ◽  
Wide Range ◽  
Spatially Resolved Spectroscopy ◽  
Stellar Envelopes

Our study, of which we give here a progress report, addresses two problems. The first is to develop methods and software permitting to compare a wide range of theoretical models of stars with envelopes with observational data produced or expected to be produced by high angular resolution optical interferometry combined with spectroscopy. The second problem is to find out the modes of interferometric observations (base length, spectral resolution etc) that are most informative for determining the physical parameters of stellar envelopes.

scholarly journals Massive star evolution revealed in the Mass-Luminosity plane

2018 ◽  
Vol 14 (S346) ◽  
pp. 480-485
Author(s):  
Erin R. Higgins ◽  
Jorick S. Vink
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Massive Star ◽  
Main Sequence ◽  
Theoretical Models ◽  
Physical Processes ◽  
Single Star ◽  
Star Evolution ◽  
Novel Method ◽  
Massive Star Evolution

AbstractMassive star evolution is dominated by key physical processes such as mass loss, convection and rotation, yet these effects are poorly constrained, even on the main sequence. We utilise a detached, eclipsing binary HD166734 as a testbed for single star evolution to calibrate new MESA stellar evolution grids. We introduce a novel method of comparing theoretical models with observations in the ‘Mass-Luminosity Plane’, as an equivalent to the HRD (see Higgins & Vink 2018). We reproduce stellar parameters and abundances of HD166734 with enhanced overshooting (αov=0.5), mass loss and rotational mixing. When comparing the constraints of our testbed to the systematic grid of models we find that a higher value of αov=0.5 (rather than αov=0.1) results in a solution which is more likely to evolve to a neutron star than a black hole, due to a lower value of the compactness parameter.

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