scholarly journals Experiments of Ultrasonic Sensing Using FBG Sensors

2011 ◽  
Vol 2-3 ◽  
pp. 148-152
Author(s):  
Wei Wei Shi ◽  
Ting Ting Hu ◽  
Yue Gang Tan
Keyword(s):  
Tunable Laser ◽  
Angular Separation ◽  
Axial Direction ◽  
Laser Source ◽  
Testing System ◽  
Linear Change ◽  
Ultrasonic Signals ◽  
Response Characteristics ◽  
Ultrasonic Sensing ◽  
Set Up

This research aims at investigating the response characteristics of fiber Bragg grating sensors (FBGs) to ultrasonic signals. The testing system was set up with a tunable laser source and the FBGs installed on the surface of an aluminum plate. Then the response characteristics of FBGs were compared, in condition of putting the ultrasonic driving source in the different longitudinal, lateral and angular separation. Measurements were taken by changing the distance between the sensor and the transducer from 60 mm to 200 mm with a step of 20 mm. Then keeping the distance at 100 mm and 200 mm respectively, do the angular experiment with the angle from 0° to 90° by the step of 10°. Experiment results show that FBG can get better signals when the transducer is along its axial direction. When the location of the transducer is changed linearly, no obvious linear change of the signal strength has been found.

scholarly journals Numerical calculation and experimental study on response characteristics of pneumatic solenoid valves

2019 ◽  
Vol 52 (9-10) ◽  
pp. 1382-1393 ◽  
Author(s):  
Xiang Zhang ◽  
Yonghua Lu ◽  
Yang Li ◽  
Chi Zhang ◽  
Rui Wang
Keyword(s):  
Switching Time ◽  
Response Characteristic ◽  
Test System ◽  
Solenoid Valve ◽  
Circuit Model ◽  
Inlet Pressure ◽  
Driving Voltage ◽  
Response Characteristics ◽  
Aerodynamic Model ◽  
Set Up

In order to analyze the response characteristics of the solenoid valve in depth, the flow field of the solenoid valve is analyzed by means of the computational fluid dynamics, and the aerodynamic parameters that are difficult to be obtained by the traditional methods are obtained with software FLUENT. We also set up the mathematical model of the solenoid valve, including the aerodynamic model, the circuit model, the magnetic circuit model and the mechanical motion model. The calculation is completed in the Simulink, and the results of the calculation are analyzed. A set of the solenoid valve response characteristic test system is built, and the response characteristic parameters such as response time and maximum action frequency of the solenoid valve are tested. The experimental results are verified by comparing them with the simulation results. The final result shows that the response characteristics are basically irrelevant to the action frequency at a suitable working frequency. The open switching time of the solenoid valve decreases with the increase in the inlet pressure and the driving voltage and increases with the increase in the number of coil turns. The close switching time increases with the increase in the inlet pressure, the driving voltage and the number of coil turns.

SENSITIVITY MEASUREMENT OF FIBRE BRAGG GRATING SENSOR

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Suzairi Daud ◽  
Muhammad Safwan Abd Aziz ◽  
Kashif Tufail Chaudhary ◽  
Mahdi Bahadoran ◽  
Jalil Ali
Keyword(s):  
Tunable Laser ◽  
Sensor System ◽  
Laser Source ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Fibre Bragg Grating ◽  
Sensor Head ◽  
Fibre Bragg Grating Sensor ◽  
Pass Through ◽  
Bragg Grating Sensor

A practical pass-through type fibre Bragg grating (FBG) temperature sensor system have been designed, developed, simulated, and experimentally investigated. The performance of FBG was evaluated in harsh environments exposed under direct sunlight, rain, and wind. The sensor system designed directly focused with convex and hand lens. The temperature of FBG’s sensor head been measured. The broadband laser source was launched into the system using tunable laser source (TLS) and both transmission and reflection spectra of FBG sensor were measured by optical spectrum analyzer (OSA). Results shows that the Bragg wavelength shift,  increased proportionally with the temperature changes. The sensitivity of FBG were recorded at 0.0100 and 0.0132 nm °C-1 for the systems where convex and hand lens applied to the FBG’s sensor head respectively, while the sensitivity of 0.0118 nm °C-1 measured for the system without any focusing element applied.

scholarly journals How to Implement Safe, Efficient and Cost-Effective SARS-CoV-2 Testing in Urban and Rural Schools within One Month

COVID ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 717-727
Author(s):  
Parastoo Kheiroddin ◽  
Magdalena Gründl ◽  
Michael Althammer ◽  
Patricia Schöberl ◽  
Linda Plail ◽  
...  
Keyword(s):  
Data Transfer ◽  
Cost Effective ◽  
Testing System ◽  
Successful Implementation ◽  
Rural And Urban ◽  
Local Involvement ◽  
Working Day ◽  
Set Up ◽  
The Individual ◽  
Time Required

(1) Background: With vaccination and new variants of SARS-CoV-2 on the horizon, efficient testing in schools may enable prevention of mass infection outbreaks, keeping schools safe places and buying time until decisions on feasibility and the necessity of vaccination in children and youth are made. We established, in the course of the WICOVIR (Where Is the COrona VIRus) study, that gargle-based pool-PCR testing offers a feasible, efficient, and safe testing system for schools in Germany when applied by central university laboratories. (2) Objectives: We evaluated whether this approach can be implemented in different rural and urban settings. (3) Methods: We assessed the arrangements required for successful implementation of the WICOVIR approach in a variety of settings in terms of transport logistics, data transfer and pre-existing laboratory set-up, as well as the time required to establish the set-up. (4) Results: We found that once regulatory issues have been overcome, all challenges pertaining to logistics, data transfer, and laboratory testing on different platforms can be solved within one month. Pooling and depooling of samples down to the individual test result were achievable within one working day in all settings. Local involvement of the community and decentralized set-ups were keys for success. (5) Conclusion: The WICOVIR gargle-based pool-PCR system is so robust and simple that it can be implemented within one month in all settings now or in future pandemics.

Study of the thermal stability of Zerodur glass ceramics suitable for a scanning probe microscope frame

Open Physics ◽  
2012 ◽  
Vol 10 (2) ◽  
Author(s):  
Ondřej Číp ◽  
Radek Šmíd ◽  
Martin Čížek ◽  
Zdeněk Buchta ◽  
Josef Lazar
Keyword(s):  
Glass Ceramic ◽  
Coefficient Of Thermal Expansion ◽  
Frequency Comb ◽  
Thermal Characteristic ◽  
Glass Ceramics ◽  
Tunable Laser ◽  
Tunable Laser Diode ◽  
Optical Mixing ◽  
Length Changes ◽  
Set Up

AbstractThe work presents measurements of the length stability of Zerodur glass ceramic with temperature change. Measurement of this thermal characteristic is necessary for determination of the optimal temperature at which the Zerodur glass ceramic has a coefficient of thermal expansion close to zero. The principle of the measurement is to monitor the length changes using an optical resonator with a cavity mirror spacer made from the Zerodur material to be studied. The resonator is placed inside a vacuum chamber with a temperature control. A tunable laser diode is locked to a certain optical mode of the resonator to monitor the optical frequency of this mode. A beat-note signal from optical mixing between the laser and a stabilized femtosecond frequency comb is detected and processed. The temperature dependence of the glass ceramics was determined and analyzed. The resolution of the length measurement of the experimental set-up is on the order of 0.1 nm.

scholarly journals Low-noise tunable deep-ultraviolet supercontinuum laser

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Callum R. Smith ◽  
Asbjørn Moltke ◽  
Abubakar I. Adamu ◽  
Mattia Michieletto ◽  
Patrick Bowen ◽  
...  
Keyword(s):  
Spectral Region ◽  
Tunable Laser ◽  
Low Noise ◽  
Laser Source ◽  
Efficient Energy Transfer ◽  
Significant Step ◽  
Deep Ultraviolet ◽  
Deep Uv ◽  
Nonlinear Compression

Abstract The realization of a table-top tunable deep-ultraviolet (UV) laser source with excellent noise properties would significantly benefit the scientific community, particularly within imaging and spectroscopic applications, where source noise has a crucial role. Here we provide a thorough characterization of the pulse-to-pulse relative intensity noise (RIN) of such a deep-UV source based on an argon (Ar)-filled anti-resonant hollow-core (AR HC) fiber. Suitable pump pulses are produced using a compact commercially available laser centered at 1030 nm with a pulse duration of 400 fs, followed by a nonlinear compression stage that generates pulses with 30 fs duration, 24.2 μJ energy at 100 kHz repetition rate and a RIN of < 1%. Pump pulses coupled into the AR HC fiber undergo extreme spectral broadening creating a supercontinuum, leading to efficient energy transfer to a phase-matched resonant dispersive wave (RDW) in the deep-UV spectral region. The center wavelength of the RDW could be tuned between 236 and 377 nm by adjusting the Ar pressure in a 140 mm length of fiber. Under optimal pump conditions the RIN properties were demonstrated to be exceptionally good, with a value as low as 1.9% at ~ 282 nm. The RIN is resolved spectrally for the pump pulses, the generated RDW and the broadband supercontinuum. These results constitute the first broadband RIN characterization of such a deep-UV source and provide a significant step forward towards a stable, compact and tunable laser source for applications in the deep-UV spectral region.

The Buckling Simulation of Planar W-Form Micro-Spring in MEMS Safety and Arming Device

2015 ◽  
Vol 645-646 ◽  
pp. 796-799
Author(s):  
Fu Fu Wang ◽  
Wen Zhong Lou ◽  
Fang Yi Liu ◽  
Da Kui Wang ◽  
Jun Lu ◽  
...  
Keyword(s):  
Extreme Environments ◽  
Compressive Force ◽  
Fem Analysis ◽  
Axial Direction ◽  
Effect Of Temperature ◽  
Micro Scale ◽  
Response Characteristics ◽  
Temperature Load ◽  
High Or Low Temperature ◽  
The Stability

This paper describes the stability research of MEMS spring used in fuze. The micro-spring in thickness dimension is thin, while the size of axial direction is larger, during compression the micro-spring is prone to suffering buckling and become unstable. In order to consider the extreme environments in launch, this paper aims to carry out buckling simulation in high or low temperature, by using FEM analysis. The effect of temperature load on the micro-spring buckling can be obtained. These researches can provide theory reference for the design applications and reliability analysis of micro-spring, and also lay the foundation for the response characteristics of the micro-scale elastic components under compressive force.

scholarly journals Inflation and rupture of vaginal tissue

2019 ◽  
Vol 9 (4) ◽  
pp. 20190029 ◽  
Author(s):  
Jeffrey A. McGuire ◽  
Christie L. Crandall ◽  
Steven D. Abramowitch ◽  
Raffaella De Vita
Keyword(s):  
Axial Direction ◽  
Image Correlation ◽  
Correlation Technique ◽  
Vaginal Tissue ◽  
Free Extension ◽  
Incorrect Diagnosis ◽  
Failure Properties ◽  
Set Up ◽  
Term Baby ◽  
Hoop Direction

Around 80% of women experience vaginal tears during labour when the diameter of the vagina must increase to allow the passage of a full-term baby. Current techniques for evaluating vaginal tears are qualitative and often lead to an incorrect diagnosis and inadequate treatment, severely compromising the quality of life of women. In order to characterize the failure properties of the vaginal tissue, whole vaginal tracts from rats ( n = 18) were subjected to free-extension inflation tests until rupture using a custom-built experimental set-up. The resulting deformations were measured using the digital image correlation technique. Overall, the strain and changes in curvature in the hoop direction were significantly larger relative to the axial direction. At a failure pressure of 110 ± 23 kPa (mean ± s.d.), the hoop and axial stresses were computed to be 970 ± 340 kPa and 490 ± 170 kPa, respectively. Moreover, at such pressure, the hoop and axial strains were found to be 12.8 ± 4.4 % and 6.4 ± 3.7 % , respectively. Rupture of the vaginal specimens always occurred in the hoop direction by tearing along the axial direction. This knowledge about the rupture properties of the vaginal tissue will be crucial for the development of clinical approaches for preventing and mitigating vaginal tearing and the associated short- and long-term traumatic conditions.

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