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Photo-Optical <i>In-Situ</i> Measurement of Drop Size Distributions: Applications in Research and Industry
摘要： The exact knowledge of Drop Size Distributions (DSD) plays a major role in various fields of applications to control and optimise processes as well as reduce waste. In the microbial production of advanced biofuels, oil droplets are produced under turbulent conditions in an aqueous medium containing many surface active components, which might hinder the recovery of the product. Knowledge of DSD is thus essential for process optimisation. This study demonstrates the capability of a photo-optical measurement method for DSD measurement in fermentation broth and in plate separators aimed at cost reduction in the microbial production of advanced biofuels. Measurements were made with model mixtures in a bioreactor, and at the inlet and outlet of a plate separator. In the bioreactor, the method was effective in detecting a broad range of droplet sizes and in differentiating other disperse components (e.g. microbial cells and gas bubbles). In the plate separator, the method was effective in determining the influence of the varied parameters on the separation efficiency.
关键词： biofuels,in-situ measurement,fermentation broth,Drop Size Distributions,plate separator,photo-optical measurement
更新于2025-09-23 15:23:52
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Formation of 45° Silicon (110) Surface Using Triton X- <i>n</i> Surfactants in Potassium Hydroxide for Infrared Applications
摘要： Silicon (Si) micromirrors are an integral feature for many micro-optomechanical systems (MOEMS). Such mirrors are generally wet etched in alkaline solution at elevated temperature. For 90? beam steering applications, 45? slanted Si (110) plane is the prime choice fabricated with the incorporation of tensioactive surfactants. Here, Triton-Si and Triton-hydroxide (OH?)/H2O interaction using varying hydrophilic chain length Triton (X-45, X-100 and X-405) were investigated. The surfactant concentration was varied from 0 to 1000 ppm in potassium hydroxide (KOH). Triton molecules were shown to adsorb preferentially on (110) than on (100) surface. Longer chain length Triton hampered OH? access to Si surface resulting in slower etch rate. In contrast, contact angle measurement suggested that shorter Triton interfaced better with Si surface. Later, Si wafers etched in Triton 10 ppm – KOH were examined. The measured output for (110)X-45, (110)X-100, (110)X-405 and polished Si wafer reference (Rq < 5?) mirrors were 0.58, 0.76, 0.72 and 1.25 mW, respectively. Subsequently, Si-SiO2 thin film in [HLHL]2-substrate configuration was fabricated. Broadband micromirror for use in 3.0–5.5 μm spectrum range was experimentally realized with reflected efficiency of 73%.
关键词： wet etching,optical measurement,Silicon micromirrors,Triton X-n,surface roughness,potassium hydroxide,surfactants
更新于2025-09-23 15:23:52
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Optical coordinate measurements in automotive industry
摘要： Photogrammetry is a technique of measuring 3D coordinates using photography as the main medium of metrology. This paper describes the use of the photogrammetric system in the automotive industry for control and measuring tasks. This contactless method is suitable for industrial application, because the measuring instruments are robust and mobile, so precise measurements are possible in production conditions. Presented results of measurements show that the optical measuring systems are powerful tools for quality control, analysis and discovering of causes of faults.
关键词： photogrammetry,optical measurement,accuracy,automotive industry
更新于2025-09-23 15:23:52
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Detection of damage of a filter by visualization of filtration process
摘要： This paper deals with testing of filters on the basis of visualization of filtration process. A filtration material can be damaged by flow of the filtered medium, high pressure drop and long-term adverse conditions. These negative effects can cause extensive damage of the filtration textile and filtration efficiency decreases. The filter can be also fractured during manufacturing, processing or by improper manipulation. A testing of a purposely damaged filtration textile is described in the article. Experiments were performed on the filtration setup which permits an optical entrance to the position where a sample of filter is placed. A laser sheet is directed into this place. Scattered light from seeding particles in front of and behind the filter is captured by a digital camera. Images from the camera are analyzed and the filtration efficiency versus time and also versus position can be obtained. Measuring chain including light scattering theory and measuring of light intensity by a digital camera are also discussed in the article.
关键词： damage detection,optical measurement,filtration,visualization,filtration efficiency
更新于2025-09-23 15:21:21
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Online optical inspection of air permeability of packaging materials during laser perforation
摘要： Laser perforations are formed in packaging to control the rate of gas exchange and maintain a balance between the respiration of the product and the permeation of the package. The air permeability of the packaging materials is typically measured using air-driven methods, but these do not allow for online measurement during the rapid production of perforations. The required permeability is generally obtained through trial and error. This paper describes the simulation of air-driven methods through computational fluid dynamics to study the effects of turbulence on the rate of air flow through perforations. A mathematical model is developed to quantify the influence of the micro-perforated size, the total area of exchange, and the thickness of the material on air permeability under certain temperature and pressure differences. The numerical results are in good agreement with the experimental results. An optical system based on the model is designed for the online inspection of packaging materials during the rapid production of laser perforations. Air permeability is precisely determined by analyzing continuous images of the perforations. Perforation characteristics such as shape, quantity, and density can also be measured to allow for feedback control of the perforation process according to the features of the packaged products. The validity and accuracy of the developed system are experimentally verified.
关键词： optical measurement,laser perforation,air permeability,CFD modeling
更新于2025-09-23 15:21:01
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Lens-less PSD measurement of flexible link deflection
摘要： Accurate measurement of change in tip position and orientation of flexible links is of substantial importance for flexible robot control applications. In this paper, a measurement system is proposed to measure the change in position and orientation at the tip of a link subjected to bending and torsion with the use of PSD (Position Sensitive Detector) sensors for space applications. Contrary to existing methods on measuring the spatial deflection of a flexible robot, the proposed method eliminates the requirement of a fragile lens or prism to obtain the angular displacement when PSD sensors are used. Experimental results for measuring five variables are presented for a cantilever flexible link when subjected to bending and torsion under a static load, thereby demonstrating the effectiveness of the proposed method.
关键词： Optical Measurement,Position Sensitive Detector,Flexible Robotic Link,Laser Diode
更新于2025-09-23 15:21:01
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High-sensitivity laser confocal tomography based on frequency-shifted feedback technique
摘要： Laser confocal tomography faces severe challenges in weak signal detection such as biological tissue imaging and low-re?ection interfaces measurement. An ultra-high sensitive optical confocal tomography based on laser frequency-shifted feedback imaging technology is presented, whose theoretical magni?cation can reach 10 6 notably without using high-gain detectors. In addition, this achievement possesses the same tomographic resolution as conventional laser confocal tomography without the need for spatial ?ltering devices. In this work, supported by theories and experiments, the lateral and vertical resolution, optical sensitivity, and system repeatability of LFCT and traditional LCT are investigated and analyzed quanti?cationally. Finally, comparison on the results of measuring the micro?uidic device and biological tissue sections is conducted.
关键词： Laser confocal tomography,High sensitivity,Frequency-shifted feedback,Optical measurement,Biological specimens imaging
更新于2025-09-23 15:19:57
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Liquid crystal-based capacitive, electro-optical and dielectric biosensors for protein quantitation
摘要： The electrical, electro-optical and dielectric properties of liquid crystals (LCs) are routinely manipulated in liquid-crystal display (LCD) devices, but their potential application in the development of biosensors is still in a nascent stage. In this review, utilising the electrical properties, electro-optical effect and dielectric anisotropy in LCs, we provide insights into several possible modes of label-free biodetection and describe how capacitance, electro-optical and dielectric measurements of various LCs assist in quantitative analysis of biomolecules. It is concluded that the electrically induced biosensing techniques proposed here provides new incentives for researchers to study the interaction between LCs and biomolecules and to resolve technical hurdles facing the development of LC-based biosensors.
关键词： bovine serum albumin,biosensing,dielectric spectroscopy,Electro-optical measurement,protein,capacitance
更新于2025-09-16 10:30:52
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[IEEE 2018 34th International Conference on Lightning Protection (ICLP) - Rzeszow (2018.9.2-2018.9.7)] 2018 34th International Conference on Lightning Protection (ICLP) - Optical Lightning Measurement System and First Results
摘要： This paper introduces a newly developed optical lightning measurement system (OLMS). The OLMS is based on a video system using a camera with a 360° panorama view and a frame rate of 60 frames per second. The OLMS locates the lightning from the direction of the illuminated lightning channel and the travel time of the thunder sound. The analysis comprises 34 flashes containing 144 strokes, which occurred during the time period from 30th of July 2017 to 24th of August 2017. The results are compared to data obtained by the European lightning location network EUCLID. The comparison revealed a flash detection efficiency of 100 % and a stroke detection efficiency of 93.1 % for EUCLID. With EUCLID, the fraction of 92.5 % was classified correctly as cloud-to-ground lightning and the minor fraction of 7.5 % was miss-classified as cloud-to-cloud lightning. On average (arithmetic mean), the negative flashes contained 4.3 return strokes with 1.7 different striking points. For multi-stroke flashes with return strokes using the same lightning channel, EUCLID located the individual striking points with a median deviation of 57.3 m. The average striking distance was about 10 km. Due to the far distance the thunder sound could often not be separated from the thunder sound of other lightning. Therefore, the OLMS located the lightning with a relatively high deviation compared to the data of EUCLID. The arithmetic (geometric) mean value of the deviation was 1330 m (670 m).
关键词： optical measurement,detection efficiency,Lightning location system (LLS),multiple lightning flash,location accuracy,selectivity CG/CC
更新于2025-09-09 09:28:46