scholarly journals On the Design of a New Simulated Inductor Using a Contactless Electrical Tomography System as an Example

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2463 ◽  
Author(s):  
Xin Ye ◽  
Yuxin Wang ◽  
Xiao-Yu Tang ◽  
Haifeng Ji ◽  
Baoliang Wang ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Research Work ◽  
Impedance Measurement ◽  
Power Source ◽  
Input Current ◽  
Output Current ◽  
Electrical Tomography ◽  
Tomography System ◽  
Coupling Capacitance ◽  
Measurement Results

This work reports a new simulated inductor which is suitable for a Contactless Electrical Tomography (CET) system and can effectively overcome the unfavorable influence of coupling capacitance on the measurement results. By detailed analysis and comparison, it is found that the grounded simulated inductor has a simple circuit construction but its output current is not equal to its input current, while the floating simulated inductor can be used as an independent inductor module but its circuit structure is relatively complex. A new simulated inductor is designed by compensating the currents from the common node of an introduced independent power source to the main circuit. The new simulated inductor combines the advantages of the grounded simulated inductor and the floating simulated inductor. It has the simple construction similar to that of the grounded simulated inductor and its input current is equal to the output current, which means it can be used as an independent module. The impedance measurement and practical image reconstruction experiments were carried out to verify the effectiveness of the new simulated inductor. The experimental results show that the design of the new simulated inductor is successful, and the performance of the impedance measurement is satisfactory. The signal-to-noise ratio of the CET system is improved. Meanwhile, the research work also indicates that in the case when the independent power source is not available, the new simulated inductor is also an effective alternative method. But the phase difference between input signal and output signal is approximately 90° when the elimination principle is realized.

Nondestructive Inspection of Thin, Low-Z Samples using Multiplexed Compton Scatter Tomography

1997 ◽  
Vol 503 ◽  
Author(s):  
B. L. Evans ◽  
J. B. Martin ◽  
L. W. Burggraf
Keyword(s):  
Signal To Noise Ratio ◽  
Reconstruction Algorithm ◽  
Filtered Backprojection ◽  
Line Broadening ◽  
Compton Scatter ◽  
X Ray ◽  
Tomography System ◽  
Transmission Computed Tomography ◽  
High Purity Germanium ◽  
Scattered Energy

ABSTRACTThe viability of a Compton scattering tomography system for nondestructively inspecting thin, low Z samples for corrosion is examined. This technique differs from conventional x-ray backscatter NDI because it does not rely on narrow collimation of source and detectors to examine small volumes in the sample. Instead, photons of a single energy are backscattered from the sample and their scattered energy spectra are measured at multiple detector locations, and these spectra are then used to reconstruct an image of the object. This multiplexed Compton scatter tomography technique interrogates multiple volume elements simultaneously. Thin samples less than 1 cm thick and made of low Z materials are best imaged with gamma rays at or below 100 keV energy. At this energy, Compton line broadening becomes an important resolution limitation. An analytical model has been developed to simulate the signals collected in a demonstration system consisting of an array of planar high-purity germanium detectors. A technique for deconvolving the effects of Compton broadening and detector energy resolution from signals with additive noise is also presented. A filtered backprojection image reconstruction algorithm with similarities to that used in conventional transmission computed tomography is developed. A simulation of a 360–degree inspection gives distortion-free results. In a simulation of a single-sided inspection, a 5 mm × 5 mm corrosion flaw with 50% density is readily identified in 1-cm thick aluminum phantom when the signal to noise ratio in the data exceeds 28.

The Effect of Prestress on Vibration Behavior of Structures in Impedance Method Damage Detection

2008 ◽  
Vol 41-42 ◽  
pp. 401-406 ◽  
Author(s):  
Xian Hua Liu ◽  
Roshun Paurobally ◽  
Jie Pan
Keyword(s):  
Damage Detection ◽  
Temperature Change ◽  
Impedance Measurement ◽  
Economic Benefits ◽  
Structural Vibration ◽  
Impedance Method ◽  
Local Vibration ◽  
Vibration Behavior ◽  
Excited Vibration ◽  
Measurement Results

Structural health monitoring or damage detection has long been a research interest for its great potential for life safety and economic benefits to the industrialized world. Structural vibration behavior is an essential signature of the integrity of structures and hence has been used for damage detection. Structural vibration impedance by way of piezoceramic patch excitation offers a local damage detection technique. It has been known that temperature change has adverse effects on the measured impedance result and can complicate the damage analysis. It is believed that one way of temperature influence on vibration is through adding thermal prestress to the structure. Prestress affects vibration in different ways on different structures and application problems. For the impedance method, prestress comes not only from temperature change but also from other sources such as wind, gravity and working load. This paper deals with prestress effects in the context of local vibration behavior of structures. A theoretical analysis is given on how prestress affects the vibration. Experimental impedance measurement results for piezoceramic patch excited vibration of simple structures such as plates under prestress are presented.

Delamination in Drilling of Sisal/Banana Reinforced Composites Produced by Hand Lay-Up Process

2017 ◽  
Vol 867 ◽  
pp. 29-33 ◽  
Author(s):  
A. Saravana Kumar ◽  
P. Maivizhi Selvi ◽  
L. Rajeshkumar
Keyword(s):  
Natural Fiber ◽  
Signal To Noise Ratio ◽  
Research Work ◽  
Synthetic Fiber ◽  
Sisal Fiber ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Banana Fiber ◽  
Fiber Reinforced Polymer Composites ◽  
Drill Tool

Natural fiber composites are presently replacing the synthetic fiber in many fields. The present research work study is an attempt to manufacture and test the sisal/banana fiber reinforced polymer composites. Composite have been manufactured using banana and sisal fiber along with epoxy resin as reinforcement. With these composites drilling has been carried out to study the factors and combination of factors that influence the delamination of drilled unidirectional sisal-banana fiber reinforced composites. Drilling experiments were performed based on the L9-Taguchi method. Delamination factor evaluated for the selected parameters spindle speed, feed and diameter of the drill tool with the help of signal to noise ratio, ANOVA analysis and to obtain the conditions for minimum delamination.

scholarly journals Multi-Function Active-Only High-Order Current-Driven Filter

2000 ◽  
Vol 23 (3) ◽  
pp. 157-161
Author(s):  
Muhammad Taher Abuelma'atti ◽  
Husain Abdullah Alzaher
Keyword(s):  
Output Voltage ◽  
High Order ◽  
Input Current ◽  
Operational Amplifiers ◽  
Output Current ◽  
Current Output ◽  
Circuit Topology ◽  
Operational Transconductance Amplifiers ◽  
Order Filter ◽  
Transconductance Amplifiers

A new multi-function high-order current-driven filter is proposed. The filter uses only operational amplifiers, and operational transconductance amplifiers (OTAs). Without using any external passive elements, a variety of high-order input-current/output-current and/or input-current/output-voltage responses can be realised without changing the circuit topology and without any matching or cancellation conditions. The parameters of the high-order filter responses can be electronically tuned by adjusting the bias currents of the OTAs.

A Prototype of Electrostatic Membrane Reflector with Composite Properties of Membrane Material

2012 ◽  
Vol 252 ◽  
pp. 237-240
Author(s):  
Guang Feng Shi ◽  
Peng Zhang
Keyword(s):  
Research Work ◽  
Numerical Control ◽  
Imaging Method ◽  
Trial Experience ◽  
Measurement Results ◽  
Design Computation ◽  
Measurement Algorithm ◽  
Incoherent Imaging ◽  
Computation Analysis ◽  
Composite Properties

Membrane reflector is light enough and deployable for launching into the space for large aperture telescope. Processes of design, computation, analysis, assembly, control, and measurement of a prototype of electrostatic polyimide reflector are introduced in this paper. And, a numerical control algorithm and a measurement algorithm based on the phase-shift and incoherent imaging method are developed for this prototype. The measurement results are analyzed and the trial experience is concluded, which is very helpful for further research work in membrane reflector in the future in China.

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