scholarly journals Comparison of velocity and turbulence profiles obtained with a Vectrino Profiler and PIV

2018 ◽  
Vol 40 ◽  
pp. 05070
Author(s):  
Jay Lacey ◽  
Jason Duguay ◽  
Bruce MacVicar
Keyword(s):  
High Frequency ◽  
Laboratory Experiments ◽  
Measurement Techniques ◽  
Measurement Methods ◽  
Doppler Velocity ◽  
Sweet Spot ◽  
Turbulence Statistics ◽  
Significant Bias ◽  
Turbulent Statistics ◽  
Background Turbulence

Laboratory experiments were carried out in a small openchannel hydraulic flume at the Université de Sherbrooke. A PIV and an acoustic Doppler velocity profiler (Vectrino II (VII)) were used to measure high frequency velocities in profiles along the centreline of a small openchannel flume. Two background turbulence levels were tested. Comparisons were made of mean and turbulent statistics obtained with the two measurement techniques. The results show reasonable agreement between mean streamwise and lateral velocities measured with the PIV and VII near the “sweet spot” of the VII. In contrast, mean vertical velocities deviate substantially between the two measurement methods. Turbulence statistics have somewhat similar profile shapes, yet significant bias is observed between the two measurement methods.

Effect of PM characterization on PM oxidative potential by acellular assays: a review

2020 ◽  
Vol 35 (4) ◽  
pp. 461-470
Author(s):  
Huibin Guo ◽  
Lei Jin ◽  
Sijing Huang
Keyword(s):  
Lung Cancer ◽  
Ascorbic Acid ◽  
Health Risks ◽  
Measurement Techniques ◽  
Measurement Methods ◽  
Redox Properties ◽  
Oxidative Potential ◽  
Cellular Assays ◽  
Copper Manganese ◽  
Risk Ratios

AbstractThe health risks brought by particles cannot be present via a sole parameter. Instead, the particulate matter oxidative potential (PM OP), which expresses combined redox properties of particles, is used as an integrated metric to assess associated hazards and particle-induced health effects. OP definition provides the capacity of PM toward target oxidation. The latest technologies of a cellular OP measurement has been growing in relevant studies. In this review, OP measurement techniques are focused on discussing along with PM characterization because of many related studies via OP measurements investigating relationship with human health. Many OP measurement methods, such as dithiothreitol (DTT), ascorbic acid (AA), glutathione (GSH) assay and other a cellular assays, are used to study the association between PM toxicity and PM characterization that make different responses, including PM components, size and sources. Briefly, AA and DTT assays are sensitive to metals (such as copper, manganese and iron etc.) and organics (quinones, VOCs and PAH). Measured OP have significant association with certain PM-related end points, for example, lung cancer, COPD and asthma. Literature has found that exposure to measured OP has higher risk ratios than sole PM mass, which may be containing the PM health-relevant fraction. PM characterization effect on health via OP measurement display a promising method.

scholarly journals Machine Vision-Based Pilling Assessment: A Review

2015 ◽  
Vol 10 (3) ◽  
pp. 155892501501000 ◽  
Author(s):  
Rocco Furferi ◽  
Lapo Governi ◽  
Yary Volpe
Keyword(s):  
Machine Vision ◽  
Textile Industry ◽  
Measurement Techniques ◽  
Measurement Methods ◽  
Automatic Machine ◽  
Defect Assessment ◽  
Textile Fabrics ◽  
Textile Technology ◽  
The World ◽  
Fabric Surface

Pilling is an undesired defect of textile fabrics, consisting of a surface characterized by a number of roughly spherical masses made of entangled fibers. Mainly caused by the abrasion of fabric surface occurring during washing and wearing of fabrics, this defect needs to be accurately controlled and measured by companies working in the textile industry. Pilling measurement is traditionally performed using manual procedures involving visual control of fabric surface by human experts. Since the early nineties, great efforts in developing automatic and non-intrusive methods for pilling measurement have been made all around the world with the final aim of overcoming traditional, visual-based and subjective procedures. Machine Vision proved to be among the best options to perform such defect assessment since it provided increasingly performing measurement equipment and tools, serving the purpose of automatic control. In particular, a relevant number of interesting works have been proposed so far, sharing the idea of helping (or even replacing) traditional measurement methods using image processing-based ones. The present work provides a rational and chronological review of the most relevant methods for pilling measurement proposed so far. This work serves the purposes of 1) understanding whether today's automatic machine vision-based pilling measurement techniques are ready for supplanting traditional pilling measurement and 2) providing textile technology researchers with a bird's eye view of the main methods studied to confront with this problem.

Comparison of Sand Patch Test and Multi Laser Profiler in Pavement Surface Measurement

2014 ◽  
Vol 70 (4) ◽  
Author(s):  
Haryati Yaacob ◽  
Norhidayah Abdul Hassan ◽  
Mohd Rosli Hainin ◽  
Muhammad Fudhail Rosli
Keyword(s):  
Regression Analysis ◽  
Patch Test ◽  
Measurement Techniques ◽  
Test Methods ◽  
Measurement Methods ◽  
Surface Measurement ◽  
Test Analysis ◽  
Pavement Surface ◽  
Road Pavement ◽  
Sand Patch

Pavement surface texture has been assessed with variety of test methods such as sand patch test and multi laser profiler. In recent years, road administrations face the issues of handling data acquired by totally different methods and the inconsistent correlation between different methods. Therefore, the objective of this study is to determine and compare the texture depth value of road pavement measured by different methods namely sand patch test and multi laser profiler. This paper compares the results of two measurement methods for pavement surface macro texture which referred as mean texture depth (MTD). Tests were conducted along North–South Expressway, between km 110.5 and km 107.2 (Southbound). T-test analysis shows that there is statistically significance difference on the result obtained between these methods along emergency lane. However for slow lanes,it was found that there is no significance between sand patch test and laser based measurement. Regression analysis shows that the coefficient of correlation, R obtained from emergency lane is 0.3719 and slow lane is 0.4579. These results generally conclude that there were weak correlations between the result of these two measurement techniques.

High-frequency measurement techniques for magnetic cores

1990 ◽  
Vol 5 (1) ◽  
pp. 41-53 ◽  
Author(s):  
V.J. Thottuvelil ◽  
T.G. Wilson ◽  
H.A. Owen
Keyword(s):  
High Frequency ◽  
Measurement Techniques ◽  
Frequency Measurement ◽  
Magnetic Cores

Non-Intrusive ECG Measurement on Vehicle Steering Wheel and Driver Seat

2008 ◽  
Author(s):  
Shan Hu ◽  
Xun Yu
Keyword(s):  
Continuous Monitoring ◽  
Traffic Accidents ◽  
Measurement Techniques ◽  
Measurement Methods ◽  
Steering Wheel ◽  
Sleep Stages ◽  
Ecg Signal ◽  
Driver Drowsiness ◽  
Waking And Sleep ◽  
Electrocardiogram Ecg

Driver drowsiness is one of the major causes of deadly traffic accidents. Continuous monitoring of drivers’ drowsiness thus is of great importance for preventing drowsiness-caused accidents. Previous psychophysiological studies have shown that heart rate variability (HRV) has established differences between waking and sleep stages [1, 2]. This offers a way to detect driver’s drowsiness by analyzing HRV, which is typically measured and analyzed from electrocardiogram (ECG) signal. Although ECG measurement techniques are well developed, most of them involve electrode contacts on chest or head. Wiring and discomfort problems inherent in those techniques prevent implementing them on cars. To address these problems, we make full use of the environment settings in a car to develop two non-intrusive real-time ECG measurement methods for drivers.

scholarly journals The Anna's hummingbird chirps with its tail: a new mechanism of sonation in birds

2008 ◽  
Vol 275 (1637) ◽  
pp. 955-962 ◽  
Author(s):  
Christopher James Clark ◽  
Teresa J Feo
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Laboratory Experiments ◽  
Wild Birds ◽  
High Speed Video ◽  
Calypte Anna

A diverse array of birds apparently make mechanical sounds (called sonations) with their feathers. Few studies have established that these sounds are non-vocal, and the mechanics of how these sounds are produced remains poorly studied. The loud, high-frequency chirp emitted by a male Anna's hummingbird ( Calypte anna ) during his display dive is a debated example. Production of the sound was originally attributed to the tail, but a more recent study argued that the sound is vocal. Here, we use high-speed video of diving birds, experimental manipulations on wild birds and laboratory experiments on individual feathers to show that the dive sound is made by tail feathers. High-speed video shows that fluttering of the trailing vane of the outermost tail feathers produces the sound. The mechanism is not a whistle, and we propose a flag model to explain the feather's fluttering and accompanying sound. The flag hypothesis predicts that subtle changes in feather shape will tune the frequency of sound produced by feathers. Many kinds of birds are reported to create aerodynamic sounds with their wings or tail, and this model may explain a wide diversity of non-vocal sounds produced by birds.

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