Determination of polarization properties of piezoelectric nanocomposite particles (BiFe0.9Co0.1O3) using fiber-optic cantilever beam deflection approach

A sol-gel based fiber-optic biosensor with acetylcholinesterase as the biorecognition element has been developed for the rapid determination of organophosphorus pesticides. Nine fluorescent indicators, acridine, acridine orange, neutral red, DAPI, rhodamine B, fluorescein, umbelliferone, FITC on celite and FITC-dextran, have been examined to optimize the fiber-optic system. Results showed that acridine and FITCs were sensitive to the change of pH value caused by the enzyme-substrate catalysis reaction. However, the sensitivity of acridine was 260 times lower than that of FITCs. Higher toxicity of acridine to acetylcholinesterase than FITC was also observed. Moreover, the high-molecular-weight FITC-dextran showed low leakage rate when immobilizing using sol-gel technology, showing that the FITC-dextran was a suitable pH sensitive fluorescent indicator for the OPPs biosensor. The response of the fiber-optic biosensor to the substrate, acetylcholine, was highly reproducible (RSD=3.5%). A good linearity of acetylcholine in the range from 0.5 to 20 mM was also obtained (R2=0.98). Furthermore, a 30% inhibition can be achieved in 30min when 152 ppb paraoxon was added into the system. The results show the possibility for real-time determination of organophosphorus pesticides by using the biosensor developed in this study.

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Determination of gradient index based on laser beam deflection by stochastic particle swarm optimization

Applied Physics B ◽

10.1007/s00340-021-07676-9 ◽

2021 ◽

Vol 127 (9) ◽

Author(s):

Linyang Wei ◽

Guojun Li ◽

Miaomiao Song ◽

Cun-Hai Wang ◽

Weijun Zhang

Keyword(s):

Particle Swarm Optimization ◽

Laser Beam ◽

Particle Swarm ◽

Beam Deflection ◽

Gradient Index ◽

Swarm Optimization ◽

Stochastic Particle

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Error analyses of a Multi-Input-Multi-Output cantilever beam test

Journal of Vibration and Control ◽

10.1177/10775463211033733 ◽

2021 ◽

pp. 107754632110337

Author(s):

Arup Maji ◽

Fernando Moreu ◽

James Woodall ◽

Maimuna Hossain

Keyword(s):

Transfer Function ◽

Frequency Domain ◽

Cantilever Beam ◽

Transfer Functions ◽

Linear Superposition ◽

Transfer Function Matrix ◽

Error Analyses ◽

Pseudo Inverse ◽

Function Matrix

Multi-Input-Multi-Output vibration testing typically requires the determination of inputs to achieve desired response at multiple locations. First, the responses due to each input are quantified in terms of complex transfer functions in the frequency domain. In this study, two Inputs and five Responses were used leading to a 5 × 2 transfer function matrix. Inputs corresponding to the desired Responses are then computed by inversion of the rectangular matrix using Pseudo-Inverse techniques that involve least-squared solutions. It is important to understand and quantify the various sources of errors in this process toward improved implementation of Multi-Input-Multi-Output testing. In this article, tests on a cantilever beam with two actuators (input controlled smart shakers) were used as Inputs while acceleration Responses were measured at five locations including the two input locations. Variation among tests was quantified including its impact on transfer functions across the relevant frequency domain. Accuracy of linear superposition of the influence of two actuators was quantified to investigate the influence of relative phase information. Finally, the accuracy of the Multi-Input-Multi-Output inversion process was investigated while varying the number of Responses from 2 (square transfer function matrix) to 5 (full-rectangular transfer function matrix). Results were examined in the context of the resonances and anti-resonances of the system as well as the ability of the actuators to provide actuation energy across the domain. Improved understanding of the sources of uncertainty from this study can be used for more complex Multi-Input-Multi-Output experiments.

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