scholarly journals An Ultrasonic Laminated Transducer for Viscoelastic Media Detection

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7188
Author(s):  
Shunmin Yang ◽  
Wenai Song ◽  
Yifang Chen ◽  
Lu Yang ◽  
Mingquan Wang ◽  
...  
Keyword(s):  
Detection System ◽  
Ultrasonic Method ◽  
Sound Field ◽  
Ultrasonic Waves ◽  
Quantitative Detection ◽  
Scanning System ◽  
Viscoelastic Media ◽  
Qualitative And Quantitative ◽  
Rocket Propellants ◽  
Solid Rocket

Based on the principle of underwater transducers, an ultrasonic four-laminated transducer with a frequency of 1 MHz was proposed to solve the problem of large energy attenuation when ultrasonic waves propagate in viscoelastic media. First, this study targeted solid rocket propellant as the research object, and the energy attenuation characteristics of ultrasonic waves propagating in viscoelastic media were analyzed through the derivation of the wave equation. Second, the structure of a four-laminated transducer with a frequency of 1 MHz was designed, and the resonance frequency was obtained by a graphical method. The sound field simulation and experimental results showed that the gain of the four-laminated transducer was 15 dB higher than that of the single-wafer transducer. An ultrasonic feature scanning system was built to complete the qualitative and quantitative detection of the smallest artificial hole (ϕ2 mm × 10 mm). Finally, two different natural defects were scanned, and the results were compared with those obtained using an industrial computed tomography detection system. The results showed that the ultrasonic method was more accurate in characterizing two natural defects. The primary cause was that the industrial CT was not sensitive to defects parallel to the incident direction of the ray. Therefore, this study not only achieved the qualitative and quantitative nondestructive testing of solid rocket propellants, but also provides an important reference for other viscoelastic components.

Quantitative analysis of direct oral anticoagulant rivaroxaban by terahertz spectroscopy

The Analyst ◽  
2020 ◽  
Vol 145 (11) ◽  
pp. 3909-3915 ◽  
Author(s):  
Xu Wu ◽  
Liping Wang ◽  
Yan Peng ◽  
Fang Wu ◽  
Jiumei Cao ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Oral Anticoagulant ◽  
Terahertz Spectroscopy ◽  
New Method ◽  
Quantitative Detection ◽  
Direct Oral Anticoagulant ◽  
Qualitative And Quantitative

A new method for the qualitative and quantitative detection of direct oral anticoagulant rivaroxaban by terahertz spectroscopy.

Quantitative Detection System for Maize Sample Containing Combined-Trait Genetically Modified Maize

2005 ◽  
Vol 77 (22) ◽  
pp. 7421-7428 ◽  
Author(s):  
Hiroshi Akiyama ◽  
Takahiro Watanabe ◽  
Kaoru Wakabayashi ◽  
Shinsuke Nakade ◽  
Shuji Yasui ◽  
...  
Keyword(s):  
Detection System ◽  
Genetically Modified ◽  
Quantitative Detection ◽  
Genetically Modified Maize ◽  
Maize Sample

scholarly journals TECHNIQUE AND DEVICE FOR THE EXPERIMENTAL ESTIMATION OF THE ACOUSTIC IMPEDANCE OF VISCOELASTIC MEDIUM

2017 ◽  
Vol 8 (4) ◽  
pp. 314-326 ◽  
Author(s):  
O. V. Murav’eva ◽  
V. V. Murav’ev ◽  
D. V. Zlobin ◽  
O. P. Bogdan ◽  
V. N. Syakterev ◽  
...  
Keyword(s):  
Acoustic Impedance ◽  
Experimental Evaluation ◽  
Piezoelectric Element ◽  
Electric Circuit ◽  
Biological Tissues ◽  
Ultrasonic Waves ◽  
Acoustic Parameters ◽  
Laboratory Equipment ◽  
Viscoelastic Media ◽  
Silicone Sealant

Measuring the characteristics of process fluids allows us to evaluate their quality, biological tissues – to differentiate healthy tissues and tissues with pathologies. Measuring the characteristics of process fluids allows us to evaluate their quality, biological tissues – to differentiate healthy tissues and tissues with pathologies. One of the complex acoustic parameters is the impedance, which allows one to fully evaluate the characteristics of viscoelastic media. Most of impedance methods of measurements require using two or more reference media and the availability of calibrated acoustic transducers. The aim of this work ware introduced a methods and construction for the experimental evaluation of the longitudinal and shear impedance of viscoelastic media based on measuring the parameters of the amplitude-frequency characteristics and calculating the elements of the electric circuit for replacing the piezoelectric element which vibrating in the test medium.The paper introduces a methods and construction of the experimental evaluation of the impedances of viscoelastic media. The suggested methods is allowed measuring longitudinal and shear impedances and determining velocities of longitudinal and transverse ultrasonic waves and the values of the elastic moduli of viscoelastic media, including in various aggregate states. The technique is fairly simple to implement and can be reproduced using simple laboratory equipment.The obtained values of the acoustic impedances of the investigated media are in satisfactory agreement with their reference data. In contrast to the known methods for determining the acoustic impedance, the developed technique allows us to estimate with sufficient accuracy the parameter of the shear impedance of viscoelastic media that is difficult to measure at the frequencies of the megahertz range, which determines the shear modulus of the material and characterizes its resistance to shear deformations. The results of the implementation of the developed technique for the estimation of acoustic parameters for a number of media with zero shear elasticity (alcohol, acetone) and viscoelastic media (glycerin, architectural clay, silicone sealant and glue МР-55 before and after polymerization) are presented.

scholarly journals Using a qualitative and quantitative validation methodology to evaluate a drone detection system

ACTA IMEKO ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 20
Author(s):  
Daniela Doroftei ◽  
Geert De Cubber
Keyword(s):  
Detection System ◽  
Weather Conditions ◽  
Careful Consideration ◽  
Technical Aspects ◽  
Operational Conditions ◽  
Qualitative And Quantitative ◽  
Detection Systems ◽  
Quantitative Score ◽  
Validation Procedure ◽  
Quantitative Validation

Now that the use of drones is becoming more common, the need to regulate the access to airspace for these systems is becoming more pressing. A necessary tool in order to do this is a means of detecting drones. Numerous parties have started the development of such drone detection systems. A big problem with these systems is that the evaluation of the performance of drone detection systems is a difficult operation that requires the careful consideration of all technical and non-technical aspects of the system under test. Indeed, weather conditions and small variations in the appearance of the targets can have a huge difference on the performance of the systems. In order to provide a fair evaluation, it is therefore paramount that a validation procedure that finds a compromise between the requirements of end users (who want tests to be performed in operational conditions) and platform developers (who want statistically relevant tests) is followed. Therefore, we propose in this article a qualitative and quantitative validation methodology for drone detection systems. The proposed validation methodology seeks to find this compromise between operationally relevant benchmarking (by providing qualitative benchmarking under varying environmental conditions) and statistically relevant evaluation (by providing quantitative score sheets under strictly described conditions).

scholarly journals Synthesis of HTPB using a semi-batch method

2020 ◽  
pp. 192-202
Author(s):  
Michał Chmielarek ◽  
Wincenty Skupiński ◽  
Zdzisław Wieczorek
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Peroxide ◽  
Synthesis Method ◽  
Batch Method ◽  
Synthesis Conditions ◽  
Rocket Propellants ◽  
Wide Range ◽  
Military Applications ◽  
Solid Rocket ◽  
Solid Rocket Propellants

Hydroxyl-terminated polybutadiene is widely used in industry for both civil and military applications. In munitions, HTPB is mostly used as a binder for heterogenic rocket propellants and as a component of plastic bonded explosives, as well as a phlegmatizer in explosives sensitive to friction and impact. The wide range of HTPB applications results from the good mechanical properties of HTPB-based polyurethanes, in particular at temperatures down to –40 °C. A synthesis method for HTPB, different from the commonly used semi-batch and continuous methods, is presented. The effect of parameters including reaction temperature, 1,3-butadiene pressure and hydrogen peroxide concentration on the properties of the obtained polymer is determined. The synthesis conditions enabling new HTPB species to be obtained, which meet the requirements for binders used in solid rocket propellants, are specified.

Qualitative and Quantitative Detection of Protein and Genetic Traits in Genetically Modified Food

2004 ◽  
Vol 20 (3) ◽  
pp. 275-296 ◽  
Author(s):  
P. Markoulatos ◽  
N. Siafakas ◽  
A. Papathoma ◽  
E. Nerantzis ◽  
B. Betzios ◽  
...  
Keyword(s):  
Genetically Modified ◽  
Quantitative Detection ◽  
Genetically Modified Food ◽  
Genetic Traits ◽  
Qualitative And Quantitative
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