DIRECT OBSERVATION OF THE ORIENTATIONAL FLUCTUATIONS IN A NEMATIC LIQUID CRYSTAL WITH A HIGH-SPEED CAMERA

2001 ◽  
Vol 366 (1) ◽  
pp. 143-149 ◽  
Author(s):  
Hiroshi Orihara ◽  
Akira Sakai ◽  
Tomoyuki Nagaya
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Direct Observation ◽  
High Speed ◽  
High Speed Camera

Dynamic characteristics of nematic liquid crystal variable retarders investigated by a high-speed polarimetry

2019 ◽  
Vol 21 (6) ◽  
pp. 065605 ◽  
Author(s):  
Song Zhang ◽  
Chao Chen ◽  
Hao Jiang ◽  
Honggang Gu ◽  
Xiuguo Chen ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Dynamic Characteristics ◽  
High Speed

Kinetics of elastic twinning in calcite

1962 ◽  
Vol 270 (1343) ◽  
pp. 525-537 ◽  
Keyword(s):  
Activation Energy ◽  
Shear Stress ◽  
Direct Observation ◽  
High Speed ◽  
High Speed Camera ◽  
Temperature Range ◽  
Applied Shear Stress ◽  
Velocity Of Propagation ◽  
Twin Propagation ◽  
Kinetics Of

An investigation of the effect of localized transient stresses on calcite is described. It is shown that twinning may or may not occur, depending on the duration of the stress pulse, the temperature and a factor related to the length of twin which may be formed. An hypothesis is suggested to explain the results and, from it, the velocity of propagation of twin lamellae is calculated in the temperature range from 20 to 300 °C. An activation energy for twin propagation is also calculated. Direct observation of the twinning process using a high-speed camera has confirmed the above hypothesis and results and has shown that the velocity of propagation of twin lamellae in calcite is not very dependent on the applied shear stress.

scholarly journals Particle Track and Trace during Membrane Filtration by Direct Observation with a High Speed Camera

Membranes ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 68
Author(s):  
Mads Koustrup Jørgensen ◽  
Kristian Boe Eriksen ◽  
Morten Lykkegaard Christensen
Keyword(s):  
Direct Observation ◽  
High Speed ◽  
Membrane Filtration ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Fluid Velocity ◽  
High Speed Camera ◽  
Particle Track ◽  
Particle Rotation ◽  
Particle Velocities

A methodology was developed for direct observation and analysis of particle movements near a microfiltration membrane. A high speed camera (1196 frames per second) was mounted on a microscope to record a hollow fiber membrane in a filtration cell with a transparent wall. Filtrations were conducted at varying pressure and crossflow velocities using synthetic core–shell particles (diameter 1.6 μm) of no and high negative surface charge. MATLAB scripts were developed to track the particle positions and calculate velocities of particle movements across and towards the membrane surface. Data showed that the velocity of particles along the membrane increases with distance from the membrane surface which correlates well with a fluid velocity profile obtained from CFD modelling. Particle track and trace was used to calculate the particle count profiles towards the membrane and document a higher concentration of particles near the membrane surface than in the bulk. Calculation of particle velocity towards and away from the membrane showed a region within 3–80 μm from the membrane surface with particle velocities higher than expected from the velocity of water through the membrane, thus the permeation drag underpredicts the actual velocity of particles towards the membrane. Near the membrane, particle velocities shift direction and move away. This is not described in classical filtration theory, but it has been speculated that this is an effect of particle rotation or due to membrane vibration or change in flow pattern close to the membrane.

Optimization of Panel Parameters and Drive Signals for High-Speed Matrix Addressing of a Bistable Twisted-Nematic Liquid Crystal Display

1999 ◽  
Vol 38 (Part 1, No. 2A) ◽  
pp. 809-813 ◽  
Author(s):  
Gi-Dong Lee ◽  
Ku Hyun Park ◽  
Ki Chul Jang ◽  
Tae-Hoon Yoon ◽  
Jae Chang Kim ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
High Speed ◽  
Liquid Crystal Display ◽  
Twisted Nematic ◽  
Twisted Nematic Liquid Crystal ◽  
Drive Signals
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