Whole Field Measurement of Temperature in Water Using Two-Color Laser Induced Fluorescence
01 Nov 1997-
TL;DR: In this paper, a technique is described that measures the instantaneous three-dimensional temperature distribution in water using two-color laser-induced fluorescence (LIF) and two fluorescent dyes, Rhodamine B and Rhodamine 110, are used as temperature indicators.
Abstract: A technique is described that measures the instantaneous three-dimensional temperature distribution in water using two-color laser-induced fluorescence (LIF). Two fluorescent dyes, Rhodamine B and Rhodamine 110, are used as temperature indicators. A laser light sheet scanned across the entire measurement volume excites the fluorescent dye, and an optical system involving a color beam splitter gives the intensity distribution of the individual fluorescent dyes on two separate monochrome CCD cameras. The ratio of these fluorescence intensities at each point of the image is calibrated against the temperature to eliminate the effect of the fluctuation of illuminating light intensity. A stable thermally stratified layer was measured by this system to evaluate the total accuracy of the measurement system. The random error of the measurement was ±1.4 K with 95% confidence. Measurements of thermal convection over a heated horizontal surface show temperature iso-surfaces having typical structures such as plumes, ridges and thermals.
Citations
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TL;DR: In this paper, the fundamental concepts for how to devise and apply quantitative measurement techniques for studies of fuel concentration, temperature, and fuel/air ratio in practical combustion systems, with some emphasis on internal combustion engines.
561 citations
TL;DR: Recent research on chip substrates, surface treatments, PCR reaction volume and speed, architecture, approaches to eliminating cross-contamination and control and measurement of temperature and liquid flow is summarized.
Abstract: The possibility of performing fast and small-volume nucleic acid amplification and analysis on a single chip has attracted great interest. Devices based on this idea, referred to as micro total analysis, microfluidic analysis, or simply ‘Lab on a chip’ systems, have witnessed steady advances over the last several years. Here, we summarize recent research on chip substrates, surface treatments, PCR reaction volume and speed, architecture, approaches to eliminating cross-contamination and control and measurement of temperature and liquid flow. We also discuss product-detection methods, integration of functional components, biological samples used in PCR chips, potential applications and other practical issues related to implementation of lab-on-a-chip technologies.
475 citations
Cites methods from "Whole Field Measurement of Temperat..."
...The principle of this temperature measuring technique has been described by Sakakibara and Adrian (95)....
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TL;DR: In this article, the authors provide an overview of the key mechanisms underpinning the dual emission of various nanostructures from recent literature and discuss their relationship to optical thermometry.
Abstract: Soluble luminescent temperature probes are promising candidates for optical thermometry and thermography applications requiring precise, passive, and spatially resolved temperature data. Dual-emitting temperature sensors overcome many of the obstacles encountered with absolute intensity-based luminescence sensors, including optical occlusion, concentration variation, or nonspecificity, by providing internally referenced (ratiometric) signals. Here, we provide an overview of the key mechanisms underpinning the dual emission of various nanostructures from recent literature and discuss their relationship to optical thermometry.
369 citations
TL;DR: The luminescence color was determined by the population of the two distinct excited-state conformations-a local excited state (high temperature) and a twisted intramolecular charge-transfer state (low temperature).
Abstract: Feeling blue: the luminescence of a triarylboron compound has a high quantum yield (at least 0.64) over a wide temperature range (-50 to +100 °C) and changes from green to blue as the temperature is increased. The luminescence color was determined by the population of the two distinct excited-state conformations-a local excited state (high temperature) and a twisted intramolecular charge-transfer state (low temperature).
307 citations
TL;DR: The detailed numerical analysis revealed that the vast majority of steady state heat rejection is through lower substrate of the chip, which was significantly impeded in the former case by the lower thermal conductivity PDMS substrate.
Abstract: Joule heating is a significant problem in electrokinetically driven microfluidic chips, particularly polymeric systems where low thermal conductivities amplify the difficulty in rejecting this internally generated heat. In this work, a combined experimental (using a microscale thermometry technique) and numerical (using a 3D "whole-chip" finite element model) approach is used to examine Joule heating and heat transfer at a microchannel intersection in poly(dimethylsiloxane)(PDMS), and hybrid PDMS/Glass microfluidic systems. In general the numerical predictions and the experimental results agree quite well (typically within +/- 3 degree C), both showing dramatic temperature gradients at the intersection. At high potential field strengths a nearly five fold increase in the maximum buffer temperature was observed in the PDMS/PDMS chips over the PDMS/Glass systems. The detailed numerical analysis revealed that the vast majority of steady state heat rejection is through lower substrate of the chip, which was significantly impeded in the former case by the lower thermal conductivity PDMS substrate. The observed higher buffer temperature also lead to a number of significant secondary effects including a near doubling of the volume flow rate. Simple guidelines are proposed for improving polymeric chip design and thereby extend the capabilities of these microfluidic systems.
295 citations
References
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TL;DR: In this article, a general experimental calibration procedure is described which determines the magnification matrix of a distorted imaging system, and an algorithm is presented to compute accurate velocity field displacements from measurements of distorted PIV images.
Abstract: Optical distortion due to inaccurate optical alignment, lens nonlinearity, and/or refraction by optical windows, fluid interfaces, and other optical elements of an experiment causes inaccuracy by introducing variable magnification. Since fractional changes in the magnification have a one-to-one effect on the accuracy of measuring the velocity, it is important to compensate for such distortions. A general experimental calibration procedure is described which determines the magnification matrix of a distorted imaging system, and an algorithm is presented to compute accurate velocity field displacements from measurements of distorted PIV images. These procedures form a basis for generalized stereoscopic PIV procedures which permit easy electronic registration of multiple cameras and accurate recombination of stereoscopic displacement fields to obtain the three-dimensional velocity vector field.
625 citations
01 Nov 1997
TL;DR: In this paper, a general experimental calibration procedure is described which determines the magnification matrix of a distorted imaging system, and an algorithm is presented to compute accurate velocity field displacements from measurements of distorted PIV images.
Abstract: Optical distortion due to inaccurate optical alignment, lens nonlinearity, and/or refraction by optical windows, fluid interfaces, and other optical elements of an experiment causes inaccuracy by introducing variable magnification. Since fractional changes in the magnification have a one-to-one effect on the accuracy of measuring the velocity, it is important to compensate for such distortions. A general experimental calibration procedure is described which determines the magnification matrix of a distorted imaging system, and an algorithm is presented to compute accurate velocity field displacements from measurements of distorted PIV images. These procedures form a basis for generalized stereoscopic PIV procedures which permit easy electronic registration of multiple cameras and accurate recombination of stereoscopic displacement fields to obtain the three-dimensional velocity vector field.
616 citations
TL;DR: In this paper, the fundamental concepts for how to devise and apply quantitative measurement techniques for studies of fuel concentration, temperature, and fuel/air ratio in practical combustion systems, with some emphasis on internal combustion engines.
561 citations
TL;DR: Recent research on chip substrates, surface treatments, PCR reaction volume and speed, architecture, approaches to eliminating cross-contamination and control and measurement of temperature and liquid flow is summarized.
Abstract: The possibility of performing fast and small-volume nucleic acid amplification and analysis on a single chip has attracted great interest. Devices based on this idea, referred to as micro total analysis, microfluidic analysis, or simply ‘Lab on a chip’ systems, have witnessed steady advances over the last several years. Here, we summarize recent research on chip substrates, surface treatments, PCR reaction volume and speed, architecture, approaches to eliminating cross-contamination and control and measurement of temperature and liquid flow. We also discuss product-detection methods, integration of functional components, biological samples used in PCR chips, potential applications and other practical issues related to implementation of lab-on-a-chip technologies.
475 citations
TL;DR: In this article, the authors provide an overview of the key mechanisms underpinning the dual emission of various nanostructures from recent literature and discuss their relationship to optical thermometry.
Abstract: Soluble luminescent temperature probes are promising candidates for optical thermometry and thermography applications requiring precise, passive, and spatially resolved temperature data. Dual-emitting temperature sensors overcome many of the obstacles encountered with absolute intensity-based luminescence sensors, including optical occlusion, concentration variation, or nonspecificity, by providing internally referenced (ratiometric) signals. Here, we provide an overview of the key mechanisms underpinning the dual emission of various nanostructures from recent literature and discuss their relationship to optical thermometry.
369 citations