scholarly journals Dynamic model of control of vibration damping mode by fiber optic PEL-sensor with phase shifting of control electric voltage.

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
A.A. Pan'kov ◽  
Keyword(s):  
Optical Fiber ◽  
Dynamic Model ◽  
Electrical Impedance ◽  
Coherent Control ◽  
Mechanical Energy ◽  
Light Flux ◽  
Electric Circuit ◽  
Phase Shifting ◽  
Frequency Range ◽  
Electric Voltage

A mathematical dynamic model of the operation of the vibration pressure optical fiber piezoelectroluminescent (PEL) sensor in the damping mode was developed taking into account the electrical conductivities and Maxwell-Wagnerian relaxation of electric fields in the phases for the case of harmonic stress (vibration pressure) on the external cylindrical surface of the sensor. Analytical solution of damping of stationary axisymmetric oscillations of optical fiber PEL-sensor is obtained and investigated by applying coherent control electric voltage to electrodes of sensor with phase shifting relative to vibration pressure. Regularities of frequency dependencies for real, imaginary parts of control, informative transfer and damping coefficients of sensor are established and studied. Analysis of influence of value and shift angle of phases of control electric voltage on results of numerical simulation for intensity of light flux at output from optical fiber of sensor under action of vibration pressure is performed. Frequency dependencies were found for the electrical impedance of the AC electric circuit of the sensor in comparison with the approximation of these dependencies by electromechanical analogy. It was revealed that in the frequency range under consideration, the electrical impedance of the sensor with satisfactory accuracy is based on consideration of an equivalent electric circuit with parallel connection of frequency-dependent active and capacitive elements. Frequency range and values of control parameters are set for effective active damping of vibration pressure through conversion to Joule heat (dissipation) of mechanical energy supplied to the sensor. The results of comparing the analytical and numerical (in the ANSYS package) approaches confirm the validity and adequacy of the decisions obtained.

Optical Vibration and Acceleration Sensor With a Silicon Cantilever

1999 ◽  
Author(s):  
Mitsuteru Kimura ◽  
Katsuhisa Toshima ◽  
Harunobu Satoh
Keyword(s):  
Simple Model ◽  
Optical Fiber ◽  
Resonance Frequency ◽  
Acceleration Sensor ◽  
Frequency Range ◽  
Silicon Cantilever ◽  
All Optical ◽  
New Type ◽  
Good Agreement ◽  
Optical Vibration

Abstract A new type all optical vibration and acceleration sensor using the combination of micromachined Si cantilever and optical fiber is proposed, and its fundamental characteristics are demonstrated. The light emitted from bulb-lens set into the V-groove is reflected at the reflector formed on the Si cantilever and then recoupled into the bulb-lens. Several sensors with different length (0.64–6.0 mm long) of the Si cantilever are fabricated to compare the theoretical resonance frequency fr obtained from the simple model and experimental ones. They had good agreement. From the sensing principle the sensing frequency range of the vibration is suitable below the fr of the Si cantilever of the sensor.

Phase-shifting optical fiber sensing with rectangular-pulse binary phase modulation

2018 ◽  
Vol 100 ◽  
pp. 170-175 ◽  
Author(s):  
Zhongjie Ren ◽  
Jianxin Li ◽  
Rihong Zhu ◽  
Ke Cui ◽  
Qing He ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Phase Modulation ◽  
Rectangular Pulse ◽  
Phase Shifting ◽  
Binary Phase ◽  
Fiber Sensing ◽  
Optical Fiber Sensing

scholarly journals Cell Barrier Characterization in Transwell Inserts by Electrical Impedance Spectroscopy

2020 ◽  
Author(s):  
Matthias Wessling
Keyword(s):  
Impedance Spectroscopy ◽  
Electrical Impedance ◽  
Cell Layer ◽  
Electric Circuit ◽  
Electrical Impedance Spectroscopy ◽  
Coating Materials ◽  
Simple Method ◽  
Capacitive Properties ◽  
Membrane Coating ◽  
Permeability Enhancers

We describe an impedance-based method for cell barrier integrity testing. A four-electrode electrical impedance spectroscopy (EIS) setup can be realized by simply connecting a commercial chopstick-like electrode (STX-1) to a potentiostat allowing monitoring cell barriers cultivated in transwell inserts.Subsequent electric circuit modeling of the electrical impedance results the capacitive properties of the barrier next to the well-known transepithelial electrical resistance (TEER). The versatility of the newmethod was analyzed by the EIS analysis of a Caco-2 monolayer in response to (a) different membrane coating materials, (b) two different permeability enhancers ethylene glycol-bis(2-aminoethylether)-N,N,N’,N’-tetraacetic acid (EGTA) and saponin, and (c) sonoporation. For the different membrane coating materials, the TEERs of the standard and new protocol coincide and increase during cultivation, while the capacitance shows a distinct maximum for three different surface materials (no coating, Matrigel®, and collagen I). The permeability enhancers cause a decline in the TEER value, but only saponin alters the capacitance of the cell layer by two orders of magnitude. Hence, cell layer capacitance and TEER represent two independent properties characterizing the monolayer. The use of commercial chopstick-like electrodes to access the impedance of a barrier cultivated in transwell inserts enables remarkable insight into the behavior of the cellular barrier with no extra work for the researcher. This simple method could evolve into a standard protocol used in cell barrier research.

Analysis for Phase Control Condition of Ytterbium-doped Optical Fiber-based Phase Shifting Interferometer

2020 ◽  
Vol 70 (9) ◽  
pp. 797-803
Author(s):  
Eun Sun KIM ◽  
Hui Won KANG ◽  
Hye Jun MA ◽  
Eun Seo CHOI*
Keyword(s):  
Optical Fiber ◽  
Phase Control ◽  
Phase Shifting

scholarly journals Design of Reconfigurable Time-to-Digital Converter Based on Cascaded Time Interpolators for Electrical Impedance Spectroscopy

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1889
Author(s):  
Sounghun Shin ◽  
Yoontae Jung ◽  
Soon-Jae Kweon ◽  
Eunseok Lee ◽  
Jeong-Ho Park ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
High Frequency ◽  
Electrical Impedance ◽  
Phase Error ◽  
Electrical Impedance Spectroscopy ◽  
Time Range ◽  
Digital Converter ◽  
Frequency Range ◽  
Input Time ◽  
Interpolation Factor

This paper presents a reconfigurable time-to-digital converter (TDC) used to quantize the phase of the impedance in electrical impedance spectroscopy (EIS). The TDC in the EIS system must handle a wide input-time range for analysis in the low-frequency range and have a high resolution for analysis in the high-frequency range. The proposed TDC adopts a coarse counter to support a wide input-time range and cascaded time interpolators to improve the time resolution in the high-frequency analysis without increasing the counting clock speed. When the same large interpolation factor is adopted, the cascaded time interpolators have shorter measurement time and smaller chip area than a single-stage time interpolator. A reconfigurable time interpolation factor is adopted to maintain the phase resolution with reasonable measurement time. The fabricated TDC has a peak-to-peak phase error of less than 0.72° over the input frequency range from 1 kHz to 512 kHz and the phase error of less than 2.70° when the range is extended to 2.048 MHz, which demonstrates a competitive performance when compared with previously reported designs.

scholarly journals Relationship between moisture content and electrical impedance of carrot slices during drying

2015 ◽  
Vol 29 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Ákos Kertész ◽  
Zuzana Hlaváčová ◽  
Eszter Vozáry ◽  
Lenka Staroňová
Keyword(s):  
Moisture Content ◽  
Electrical Impedance ◽  
Fruits And Vegetables ◽  
Physiological State ◽  
Impedance Measurement ◽  
Biological Tissues ◽  
Impedance Spectra ◽  
Frequency Range ◽  
Impedance Parameters ◽  
Precision Balance

Abstract Electrical properties of food materials can give information about the inner structure and physiological state of biological tissues. Generally, the process of drying of fruits and vegetables is followed by weight loss. The aim of this study was to measure the impedance spectra of carrot slices during drying and to correlate impedance parameters to moisture content in different drying periods. Cylindrical slices were cut out from the carrot root along the axis. The slices were dried in a Venticell 111 air oven at 50°C. The weight of the slices was measured with a Denver SI-603 electronic analytical and precision balance. The weighing of the samples was performed every 30 min at the beginning of drying and every 60 min after the process. The moisture content of the samples was calculated on wet basis. The magnitude and phase angle of electrical impedance of the slices were measured with HP 4284A and 4285A precision LCR meters in the frequency range from 30 Hz to 1 MHz and from 75 kHz to 30 MHz, respectively, at voltage 1 V. The impedance measurement was performed after weighting. The change in the magnitude of impedance during drying showed a good correlation with the change in the moisture content.

Influence of Pedaling Rate on Muscle Mechanical Energy in Low Power Recumbent Pedaling Using Forward Dynamic Simulations

2007 ◽  
Author(s):  
Nils A. Hakansson ◽  
Maury L. Hull
Keyword(s):  
Low Power ◽  
Dynamic Model ◽  
Inverse Dynamics ◽  
Muscle Power ◽  
Mechanical Energy ◽  
Triceps Surae ◽  
Knee Extensors ◽  
Individual Muscle ◽  
The Individual ◽  
Pedaling Rate

An understanding of the muscle power contributions to the crank and limb segments in recumbent pedaling would be useful in the development of rehabilitative pedaling exercises. The objectives of this work were to (i) develop a forward dynamic model to simulate low-power pedaling in the recumbent position, (ii) use the model to quantify the power contributions of the muscles to driving the crank and limb segments, and (iii) determine whether there were differences in the muscle power contributions required to simulate recumbent pedaling at three different pedaling rates. A forward dynamic model was used to determine the individual muscle excitation amplitude and timing to drive simulations that best replicated experimental kinematics and kinetics of recumbent pedaling. The segment kinematics, pedal reaction forces, and electromyograms (EMG) of 10 muscles of the right leg were recorded from 16 subjects as they pedaled a recumbent ergometer at 40, 50, and 60 rpm and a constant 50 W workrate. Intersegmental joint moments were computed using inverse dynamics and the muscle excitation onset and offset timing were determined from the EMG data. All quantities were averaged across ten cycles for each subject and averaged across subjects. The model-generated kinematic and kinetic quantities tracked almost always within 1 SD of the experimental data for all three pedaling rates. The uniarticular hip and knee extensors generated 65 percent of the total mechanical work in recumbent pedaling. The triceps surae muscles transferred power from the limb segments to the crank and the bi-articular muscles that crossed the hip and knee delivered power to the crank during the leg transitions between flexion and extension. The functions of the individual muscles did not change with pedaling rate, but the mechanical energy generated by the knee extensors and hip flexors decreased as pedaling rate increased. By varying the pedaling rate, it is possible to manipulate the individual muscle power contributions to the crank and limb segments in recumbent pedaling and thereby design rehabilitative pedaling exercises to meet specific objectives.

scholarly journals Исследование электрофизических характеристик катион-замещенной керамики гексаалюмината бария методом импедансной спектроскопии

2018 ◽  
Vol 60 (2) ◽  
pp. 269
Author(s):  
Б.А. Беляев ◽  
Н.А. Дрокин ◽  
В.А. Полубояров
Keyword(s):  
Relaxation Times ◽  
Electric Circuit ◽  
Transport Processes ◽  
Impedance Spectra ◽  
Frequency Range ◽  
Equivalent Electric Circuit ◽  
Parallel Plate Capacitor ◽  
Barium Hexaaluminate ◽  
Temperature Dependences ◽  
The Difference

AbstractWe report on the behavior of frequency and temperature dependences of the impedance of a measuring cell in the form of a parallel-plate capacitor filled with barium hexaaluminate ceramics with four aluminum cations replaced by iron (BaO · 2Fe_2O_3 · 4Al_2O_3). The measurements have been performed in the frequency range of 0.5–10^8 Hz at temperatures of 20-375°C. A technique for determining the electrical properties of the investigated ceramics is proposed, which is based on an equivalent electric circuit allowing the recorded impedance spectra to be approximated with sufficiently high accuracy. The established spectral features are indicative of the presence of two electric relaxation times different from each other by three orders of magnitude. This fact is explained by the difference between the charge transport processes in the bulk of crystallites and thin intercrystallite spacers, for which the charge activation energies have been determined.

scholarly journals Импедансная спектроскопия электропроводящих композиционных материалов на основе микроволокон сополимера поливинилиденфторида с трифторэтиленом, модифицированных полипирролом

2021 ◽  
Vol 47 (11) ◽  
pp. 51
Author(s):  
В.М. Капралова ◽  
И.Ю. Сапурина ◽  
Н.Т. Сударь ◽  
А.А. Третьяков ◽  
O. Gryshkov ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Electrical Impedance ◽  
Impedance Spectra ◽  
Frequency Range ◽  
Dielectric Characteristics ◽  
Circular Arc ◽  
Nanocomposite Polymer ◽  
Nanocomposite Polymer Electrolyte ◽  
Nonwoven Materials ◽  
Composite Nonwoven

The impedance spectra of composite nonwoven materials based on nano- and microfibers of polyvinylidene fluoride-trifluoroethylene copolymer modified by polypyrrole with different doping degree were studied in the frequency range 1000 Hz-5 MHz. It was found that an increase in the doping degree of polypyrrole coating of nanofibers leads to a decrease in the imaginary and real components of the electrical impedance. Regardless of their magnitude, the shape of the hodographs is close to circular arc resting on the ReZ axis, which allows us to consider the studied material as a nanocomposite polymer electrolyte whose dielectric characteristics can be reversibly changed.

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