scholarly journals Multi-spectral imaging for Thermochromic Liquid Crystal based Particle Image Thermometry: A proof of concept

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Theo Käufer ◽  
Sebastian Moller ◽  
Maik Rosenberger ◽  
Gunther Notni ◽  
Christian Cierpka
Keyword(s):  
Liquid Crystal ◽  
Thermal Stratification ◽  
Particle Image ◽  
Central Element ◽  
Spectral Imaging ◽  
Ground Truth ◽  
Maximum Deviation ◽  
Calibration Data ◽  
Thermochromic Liquid Crystal ◽  
Novel Approach

In this contribution, a novel imaging approach for Thermochromic Liquid Crystal (TLC) based Particle Image Thermometry (PIT) is demonstrated. In contrast to state of the art approaches, a multi-spectral camera was used to record the color response of the Thermochromic Liquid Crystals seeding particles. An experiment with a transparent, water-filled, cylindrical cell as the central element was set up to investigate the novel approach. The temperature in the cell can be controlled by adjusting the temperature of the bottom and top plate. Calibration images at eleven different temperatures ranging from 18 ◦C to 21.6 ◦C, as well as images of a stable thermal stratification, were recorded. 90 percent of the calibration data was used to train a neural network (NN) to predict the temperature. The remaining 10 percent of the calibration data and the data of the stable thermal stratification were used to test the NN. The tests show that the deviation between predicted and ground truth temperature is mostly below 0.1 K and that the linear profile of the stable thermal stratification can be predicted with a maximum deviation of ≈ 0.15 K. This shows that multi-spectral imaging with neural networks for data processing is feasible and a promising concept.

A novel approach to thermochromic liquid crystal calibration using neural networks

2006 ◽  
Vol 17 (7) ◽  
pp. 1918-1924 ◽  
Author(s):  
G S Grewal ◽  
M Bharara ◽  
J E Cobb ◽  
V N Dubey ◽  
D J Claremont
Keyword(s):  
Neural Networks ◽  
Liquid Crystal ◽  
Thermochromic Liquid Crystal ◽  
Novel Approach

MWIR/LWIR filter based on Liquid–Crystal Fabry–Perot structure for tunable spectral imaging detection

2015 ◽  
Vol 69 ◽  
pp. 68-73 ◽  
Author(s):  
Huaidong Zhang ◽  
Afzal Muhammad ◽  
Jun Luo ◽  
Qing Tong ◽  
Yu Lei ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Spectral Imaging ◽  
Fabry Perot ◽  
Imaging Detection

scholarly journals Practical example for use of the supervised vicarious calibration (SVC) method on multisource hyperspectral imagery data – ValCalHyp airborne hyperspectral campaign under the EUFAR framework

2014 ◽  
Vol XL-7 ◽  
pp. 51-53
Author(s):  
A. Brook ◽  
E. Ben Dor
Keyword(s):  
Atmospheric Correction ◽  
Ground Truth ◽  
Critical Issue ◽  
Radiometric Calibration ◽  
Vicarious Calibration ◽  
Flight Direction ◽  
Novel Approach ◽  
Novel Method ◽  
General Goal ◽  
Cross Calibration

A novel approach for radiometric calibration and atmospheric correction of airborne hyperspectral (HRS) data, termed supervised vicarious calibration (SVC) was proposed by Brook and Ben-Dor in 2010. The present study was aimed at validating this SVC approach by simultaneously using several different airborne HSR sensors that acquired HSR data over several selected sites at the same time. The general goal of this study was to apply a cross-calibration approach to examine the capability and stability of the SVC method and to examine its validity. This paper reports the result of the multi sensors campaign took place over Salon de Provenance, France on behalf of the ValCalHyp project took place in 2011. The SVC method enabled the rectification of the radiometric drift of each sensor and improves their performance significantly. The flight direction of the SVC targets was found to be a critical issue for such correction and recommendations have been set for future utilization of this novel method. The results of the SVC method were examined by comparing ground-truth spectra of several selected validation targets with the image spectra as well as by comparing the classified water quality images generated from all sensors over selected water bodies.

scholarly journals Liquid crystal optrode arrays: a novel approach to neural interfaces

2018 ◽  
Vol 12 ◽  
Author(s):  
François Ladouceur ◽  
Leonardo Silvestri ◽  
Josiah Firth ◽  
Amr Al Abed ◽  
Nigel Lovell
Keyword(s):  
Liquid Crystal ◽  
Neural Interfaces ◽  
Novel Approach

scholarly journals Comparison of new-generation renal artery denervation systems: assessing lesion size and thermodynamics using a thermochromic liquid crystal phantom model

2017 ◽  
Vol 13 (10) ◽  
pp. 1242-1247 ◽  
Author(s):  
Sara Al Raisi ◽  
Michael Barry ◽  
Pierre Qian ◽  
Abhishek Bhaskaran ◽  
Jim Pouliopoulos ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Renal Artery ◽  
Lesion Size ◽  
Thermochromic Liquid Crystal ◽  
Phantom Model ◽  
Renal Artery Denervation ◽  
New Generation

scholarly journals Miniature Compressive Ultra-spectral Imaging System Utilizing a Single Liquid Crystal Phase Retarder

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Isaac August ◽  
Yaniv Oiknine ◽  
Marwan AbuLeil ◽  
Ibrahim Abdulhalim ◽  
Adrian Stern
Keyword(s):  
Liquid Crystal ◽  
Imaging System ◽  
Spectral Imaging ◽  
Crystal Phase ◽  
Liquid Crystal Phase

Numerical Investigation of Thermal Separators Within the Evacuated Tubes of a Water-in-Glass Solar Water Heater

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Asif Soopee ◽  
Abdel Anwar Hossen Khoodaruth ◽  
Anshu Prakash Murdan ◽  
Vishwamitra Oree
Keyword(s):  
Tilt Angle ◽  
Thermal Efficiency ◽  
Thermal Stratification ◽  
Maximum Deviation ◽  
Water Tank ◽  
Solar Water Heater ◽  
Water Heater ◽  
Solar Water ◽  
Thermal Distribution ◽  
Evacuated Tubes

The effects of thermal separators within the evacuated tubes of a water-in-glass solar water heater (SWH) were numerically investigated using the commercial computational fluid dynamics (CFD) software ANSYS fluent. To validate the three-dimensional (3D) model, an experiment was performed for the passive operation of the SWH for a fortnight period, of which 3 h of recorded data was selected. The Boussinesq's approximation was employed, and the respective solar irradiance and ambient temperature profiles were incorporated. A maximum deviation of only 2.06% was observed between the experimental and numerical results. The model was then adapted for the case where thermal separators are inserted within the evacuated tubes of the SWH and both cases were run for two tilt angles, 10 deg and 40 deg. The temperature and velocity profiles within the evacuated tubes were analyzed alongside the temperature contours, thermal stratification, and overall thermal efficiency of the SWH. At a 40 deg tilt, without thermal separators, the flow streams within the evacuated tubes are restrained, and a chaotic thermal behavior was observed, thereby restricting thermal distribution to the water stored in the SWH tank. A lower tilt angle (10 deg) provided a more desirable thermal distribution. With thermal separators, however, the tilt angle preference was reversed. A faster and more uniform thermal distribution was achieved within the water tank, with a sizeable reduction in the thermal stratification at a 40 deg tilt. The overall thermal efficiency of the SWH was improved by 4.11% and 4.14% for tilt angles of 10 deg and 40 deg, respectively.

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