Methods for enhancement of high-sensitivity detection for a surface wave EMAT

2021 ◽  
pp. 1-23
Author(s):  
Jin Zhang ◽  
Xin Wang ◽  
Xuebing Wang ◽  
LingLing Zheng ◽  
Ruipeng Li ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Pulse Compression ◽  
Signal To Noise Ratio ◽  
Single Layer ◽  
High Sensitivity ◽  
Element Model ◽  
Industrial Applications ◽  
Detection Sensitivity ◽  
Electromagnetic Acoustic Transducer ◽  
Compression Technique

Due to the poor conversion efficiency and signal-to-noise ratio (SNR) of Electromagnetic Acoustic Transducer (EMAT) testing, the defect detection sensitivity is limited, which restricts the extensive industrial applications. A finite element model for the testing process of a meander-coil EMAT was established that considers the simplified excitation and detection circuits for the EMAT. Based on this model, the effect of the connection methods (parallel or series) of the coils in the generating and receiving EMATs on their generating and receiving efficiency was investigated, and the simulation results were validated experimentally. Subsequently, the pulse compression technique with a 13-bit Barker code was used for the EMAT detection, and improvements of the SNR and range resolution were established through numerical simulation and experimental measurement. The results show that compared with the traditional EMAT design, which comprises single-layer transmitting and receiving coils, the conversion efficiency of the optimized EMAT with two excitation and receiving coils in the parallel connection can be improved by 52.8%. With the application of the Barker-coded pulse compression to detect the ultrasonic A-scan signal with no synchronous average, the SNR of the defect echo can be improved by 9.5 dB compared with the A-scan signal with 128 synchronous averages.

scholarly journals High Sensitivity Continuous Monitoring of Chloroform Gas by Using Wavelength Modulation Photoacoustic Spectroscopy in the Near-Infrared Range

2021 ◽  
Vol 11 (15) ◽  
pp. 6992
Author(s):  
Tie Zhang ◽  
Yuxin Xing ◽  
Gaoxuan Wang ◽  
Sailing He
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Continuous Monitoring ◽  
Near Infrared ◽  
Resonant Cavity ◽  
High Sensitivity ◽  
Industrial Applications ◽  
Detection Sensitivity ◽  
Infrared Range ◽  
Wavelength Modulation ◽  
Linear Coefficient

An optical system for gaseous chloroform (CHCl3) detection based on wavelength modulation photoacoustic spectroscopy (WMPAS) is proposed for the first time by using a distributed feedback (DFB) laser with a center wavelength of 1683 nm where chloroform has strong and complex absorption peaks. The WMPAS sensor developed possesses the advantages of having a simple structure, high-sensitivity, and direct measurement. A resonant cavity made of stainless steel with a resonant frequency of 6390 Hz was utilized, and eight microphones were located at the middle of the resonator at uniform intervals to collect the sound signal. All of the devices were integrated into an instrument box for practical applications. The performance of the WMPAS sensor was experimentally demonstrated with the measurement of different concentrations of chloroform from 63 to 625 ppm. A linear coefficient R2 of 0.999 and a detection sensitivity of 0.28 ppm with a time period of 20 s were achieved at room temperature (around 20 °C) and atmosphere pressure. Long-time continuous monitoring for a fixed concentration of chloroform gas was carried out to demonstrate the excellent stability of the system. The performance of the system shows great practical value for the detection of chloroform gas in industrial applications.

Novel electrochemiluminescent materials for sensor applications

2014 ◽  
Vol 174 ◽  
pp. 357-367 ◽  
Author(s):  
Lynn Dennany ◽  
Zahera Mohsan ◽  
Alexander L. Kanibolotsky ◽  
Peter J. Skabara
Keyword(s):  
Redox Reactions ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Radical Cations ◽  
Detection Sensitivity ◽  
Sensor Development ◽  
Sensor Applications ◽  
Sensor Devices ◽  
The Impact

Electrochemiluminescence (ECL) uses redox reactions to generate light at an electrode surface, and is gaining increasing attention for biosensor development due to its high sensitivity and excellent signal-to-noise ratio. ECL studies of monodisperse oligofluorene–truxenes (T4 series) have been reported previously, showing the production of stable radical cations and radical anions, generating blue ECL. The compound in this study differs from the original structures, in that there are 2,1,3-benzothiadazole (BT) units inserted between the first and second fluorene units of the quarterfluorenyl arms. It was therefore anticipated that the incorporation of these highly luminescent and ECL-active compounds into sensor development would lead to significant decreases in detection limits. In this contribution, we report on the impact of incorporating these novel complexes into sensor devices on the ECL efficiency, as well as the ability of these to improve the detection sensitivity and decrease the limit of detection using the reagent-free detection of model analytes. The real world impact of these compounds is elucidated through the comparison with more standard ECL materials such as ruthenium-based compounds. The potential for multiple applications is to be examined within this contribution.

scholarly journals Angularly Resolved Deep Brain Fluorescence Imaging Using a Single Optical Fiber

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Israel J. De La Rosa ◽  
Mehdi Azimipour ◽  
Patrick K. Cullen ◽  
Fred J. Helmstetter ◽  
Ramin Pashaie
Keyword(s):  
Optical Fiber ◽  
Pulse Compression ◽  
Fluorescence Probe ◽  
Signal To Noise Ratio ◽  
Fluorescence Emission ◽  
Compression Technique ◽  
Excitation Light ◽  
New Device ◽  
Deep Brain

In this article, we report the development of a minimally invasive fiber optic based fluorescence probe which can reach deep brain objects and measure the intensity and spatial distribution of fluorescence signals in the tissue. In this design, the brain is scanned by a single penetrating side-firing optical fiber which delivers excitation light pulses to the tissue at different depths and orientations and simultaneously collects samples of fluorescence emission signals. Signal-to-noise ratio of the measurements is improved by adapting the pulse compression technique and the theory of optimal filters. Effects of each design parameter on the overall performance of the scanner, including the spatial resolution and speed of scanning, are analyzed and experimentally measured. In vivo experiments show that the new device, despite the simplicity of the design, provides valuable information particularly useful in optogenetic stimulation experiments where the exact position of the fiber tip and the radiation orientation can change the outcome of a test.

Oblique impact behavior of Al-LDPE-Al sandwich plates

2020 ◽  
Vol 62 (10) ◽  
pp. 998-1002
Author(s):  
Ahmet Refah ◽  
Şeyma Helin Kaya ◽  
Furkan Nuri Karaoğlu ◽  
İsmail Sağlam ◽  
Naghdali Choupani
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Sandwich Panels ◽  
Single Layer ◽  
Element Model ◽  
Oblique Impact ◽  
Industrial Applications ◽  
Impact Behavior ◽  
Metal Sheets ◽  
Polymer Metal

Abstract Metal-polymer-metal hybrid sandwich panels are gaining importance in various industrial applications due to their light weight and damping properties. When compared with composite materials, hybrid materials consisting of separate metal and thermoplastic parts can be recycled more easily. In addition to their applications in civil engineering, the aluminum-low density polyethylene-aluminum (Al-LDPE-Al) sandwich panels yield a potential use as light ballistic protection material. In this study, a standard hybrid panel of 3.2 mm polyethylene filling and 0.4 mm of two aluminum metal sheets was experimentally tested under ballistic impact. A finite element model was constructed via commercial software and validated through shooting experiments with a rifle under real conditions. The finite element model was used to simulate the oblique impact behavior of Al-LDPE-Al sandwich panels as a single layer, as 5 layers stacking and as a single layer equivalent of the stacked 5 layer. Results showed that the oblique impact does not have a significant effect on the single layer panel. Stacked layers, however, and the equivalent single layer of a stacked layer have the highest energy absorption under a 30° hitting angle.

A Design of Multi-Band UHF Sensor for Partial Discharge Detection

2013 ◽  
Vol 394 ◽  
pp. 435-440 ◽  
Author(s):  
Bin Liu ◽  
Jing De An ◽  
Wei Dong Zhang ◽  
You Lin Xu
Keyword(s):  
Signal To Noise Ratio ◽  
Partial Discharge ◽  
High Sensitivity ◽  
Ultra Wideband ◽  
Detection Sensitivity ◽  
Surface Discharge ◽  
Communication Signals ◽  
Metallic Particles ◽  
Selection Of ◽  
Multi Band

The selection and design of the sensor is one of the key technologies for UHF PD detection. The UHF sensors popular used in PD detection and location in substation are partial discharge UHF sensor are usually ultra wideband antenna in the frequency range of 200 MHz to 1.5 GHz, which contains interference from communication signals. Accordingly, in order to improve the detection sensitivity and the signal-to-noise ratio, a kind of multi-band UHF narrowband sensor is proposed and designed in accordance with the principles of the loop antenna for PD detection. The proposed frequency resonant bands are set in the ranges of 480MHz-520MHz, 800MHz-850MHz and 1.1GHz-1.2GHz. The design based on simulation is finished and the performances of the prototype sensor are researched by parametric test and PD detection of three typical discharges: corona discharge, surface discharge and metallic particles discharge generated by PD mode. Results show that the selection of band for the UHF sensor is reasonable, and the sensor is with high sensitivity.

High S/N Ratio Guided Wave Inspection of Pipe Using Chirp Pulse Compression

2004 ◽  
Author(s):  
Kiyokazu Toiyama ◽  
Takahiro Tsutsumoto ◽  
Takashi Ikeda ◽  
Takahiro Hayashi
Keyword(s):  
Long Range ◽  
Pulse Compression ◽  
Signal To Noise Ratio ◽  
Effective Means ◽  
Side Lobe ◽  
Guided Wave ◽  
Pulse Excitation ◽  
Chirp Pulse ◽  
Compression Technique ◽  
Heat Insulator

Guided wave is expected as the most promising technique for rapid long-range inspection of pipes. However, signal to noise ratio is still required to be improved, especially in highly attenuative pipes covered with heat insulator and/or buried in the ground. Recently, pulse compression technique has been developed as an effective means for improving S/N ratio in the field of radar detection. In this paper, chirp pulse compression technique was applied to the long-range inspection of pipe using guided wave. The technical brief explanation about chirp pulse compression was described. Example data signals of burst wave excitation way and chirp pulse excitation way with commonly -used amplifier were reviewed with respect to unwanted side lobe. The cause of a side lobe was investigated, and the amplifier with excellent distortion property was presented to improve S/N ratio of system with quite vanishing of side lobe.

scholarly journals A Flexible Piezoelectric Energy Harvester-Based Single-Layer WS2 Nanometer 2D Material for Self-Powered Sensors

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2097
Author(s):  
Quan Wang ◽  
Kyung-Bum Kim ◽  
Sang Bum Woo ◽  
Yoo Seob Song ◽  
Tae Hyun Sung
Keyword(s):  
Signal To Noise Ratio ◽  
Single Layer ◽  
High Sensitivity ◽  
Human Movement ◽  
Piezoelectric Sensor ◽  
Human Motion ◽  
High Signal ◽  
Human Machine Interaction ◽  
Piezoelectric Energy ◽  
Self Powered

A piezoelectric sensor is a typical self-powered sensor. With the advantages of a high sensitivity, high frequency band, high signal-to-noise ratio, simple structure, light weight, and reliable operation, it has gradually been applied to the field of smart wearable devices. Here, we first report a flexible piezoelectric sensor (FPS) based on tungsten disulfide (WS2) monolayers that generate electricity when subjected to human movement. The generator maximum voltage was 2.26 V, and the produced energy was 55.45 μJ of the electrical charge on the capacitor (capacity: 220 μF) when applying periodic pressing by 13 kg. The generator demonstrated here can meet the requirements of human motion energy because it generates an average voltage of 7.74 V (a knee), 8.7 V (a sole), and 4.58 V (an elbow) when used on a running human (weight: 75 kg). Output voltages embody distinct patterns for different human parts, the movement-recognition capability of the cellphone application. This generator is quite promising for smart sensors in human–machine interaction detecting personal movement.

scholarly journals Magnetoelastic Coupling and Delta-E Effect in Magnetoelectric Torsion Mode Resonators

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2022
Author(s):  
Benjamin Spetzler ◽  
Elizaveta V. Golubeva ◽  
Ron-Marco Friedrich ◽  
Sebastian Zabel ◽  
Christine Kirchhof ◽  
...  
Keyword(s):  
Low Frequency ◽  
High Sensitivity ◽  
Element Model ◽  
Mode Number ◽  
Frequency Change ◽  
General Description ◽  
Resonance Modes ◽  
Field Sensor ◽  
Magnetic Sensitivity ◽  
Bending Modes

Magnetoelectric resonators have been studied for the detection of small amplitude and low frequency magnetic fields via the delta-E effect, mainly in fundamental bending or bulk resonance modes. Here, we present an experimental and theoretical investigation of magnetoelectric thin-film cantilevers that can be operated in bending modes (BMs) and torsion modes (TMs) as a magnetic field sensor. A magnetoelastic macrospin model is combined with an electromechanical finite element model and a general description of the delta-E effect of all stiffness tensor components Cij is derived. Simulations confirm quantitatively that the delta-E effect of the C66 component has the promising potential of significantly increasing the magnetic sensitivity and the maximum normalized frequency change ∆fr. However, the electrical excitation of TMs remains challenging and is found to significantly diminish the gain in sensitivity. Experiments reveal the dependency of the sensitivity and ∆fr of TMs on the mode number, which differs fundamentally from BMs and is well explained by our model. Because the contribution of C11 to the TMs increases with the mode number, the first-order TM yields the highest magnetic sensitivity. Overall, general insights are gained for the design of high-sensitivity delta-E effect sensors, as well as for frequency tunable devices based on the delta-E effect.

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