Dielectric Properties in Fresh Trabecular Bone Tissue from 1MHz to 1000MHz: A Fast and Non Destructive Quality Evaluation Technique

2010 ◽  
Vol 638-642 ◽  
pp. 730-735 ◽  
Author(s):  
Ramiro M. Irastorza ◽  
Sergio Valente ◽  
Fernando Vericat ◽  
Eugenia Blangino
Keyword(s):  
Dielectric Properties ◽  
Frequency Domain ◽  
Quality Evaluation ◽  
Low Cost ◽  
Low Frequency ◽  
Electrical Impedance Spectroscopy ◽  
Sample Population ◽  
Strongly Correlated ◽  
Trabecular Bones ◽  
Non Destructive

The increasing research on development of novel bio-materials has resulted in several studies on non-destructive evaluation methods for characterizing these materials and the biological materials receiving them. A broad range of techniques are available. As an alternative tool, electrical impedance spectroscopy, has become a widely used, non destructive and low cost technique in material quality evaluation. Particularly in bones, it has also been demonstrated that mechanical characteristics are strongly correlated to dielectric properties. In this work, non destructive estimation (the same samples can be tested using other techniques) of the dielectric properties of fresh trabecular bones (layered lossy structure) using coaxial probes is analyzed from 1MHz to 10MHz (in frequency domain) and from 80MHz to 1GHz (in both, frequency and time domain). Frequency domain system identification is used to build the estimation in the low frequency range and an orthonormal based identification approach, for the high frequency data. Comments on conductive samples, non Debye dielectrics and polarization effects are added. The methodology was applied to a particular human sample population of aged adult femur heads and results are presented here. A comparison with destructive test, in which the samples were machined into cylinders of 7mm diameter, is also performed.

Dielectric properties of processed cheese

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chin Han Chan ◽  
Jean-Marc Saiter ◽  
Hubert Eudier ◽  
Hans-Werner Kammer
Keyword(s):  
Dielectric Properties ◽  
Impedance Spectroscopy ◽  
Frequency Domain ◽  
Food Quality ◽  
Low Frequency ◽  
Relaxation Behavior ◽  
Impedance Spectra ◽  
Processed Cheese ◽  
Dynamic Studies

Abstract Dynamic studies of several processed cheeses were carried out for evaluation of their dielectric properties and their relaxation behavior. Impedance spectroscopy has been used to study the systems under discussion in low-frequency domain. A substantial number of impedance spectra will be given and discussed that relate the dielectric properties to food nutrients. Also influence of moisture on food quality might be evaluated.

scholarly journals The Development of Fluxgate Magnetometer for Non–Destructive Measurement

2012 ◽  
Author(s):  
Soon Leong Chew ◽  
Rashdi Shah Ahmad ◽  
Rosly Jaafar
Keyword(s):  
Magnetic Flux ◽  
Low Cost ◽  
Current Source ◽  
Low Frequency ◽  
Ferromagnetic Material ◽  
Magnetic Sensor ◽  
Fluxgate Magnetometer ◽  
Ferrite Ring ◽  
Non Destructive ◽  
Ring Core

Pengukuran tanpa musnah bahan feromagnet dan gangguan medan magnet frekuensi rendah memerlukan penderia medan magnet yang mempunyai kepekaan yang tinggi dan stabil. Magnetometer yang berasaskan prinsip fluxgate dan memenuhi ciri-ciri yang diperlukan telah dibina dengan menggunakan teras gelang ferit. Teras gelang ferit ini dipacukan dengan sumber arus untuk mencapai keadan histerisis. Gelung pengesan yang dililit merentasi gelang ferit akan mengesan perubahan medan magnet yang berlaku pada gelang ferit tersebut. Teknik pengesanan yang digunakan adalah berasaskan pengesanan harmonik kedua oleh suatu pengesan fasa. Penderia fluxgate yang dibina adalah murah mudah dibina, mampu mengesan arah medan magnet dan tahan lasak. Kata kunci: Fluxgate; penderia medan magnet; histerisis; feromagnet Non–Destructive measurements of ferromagnetic material and low frequency magnetic flux distrubance require a highly sensitive and stable magnetic sensor with directional capabilities. A magnetometer based on fluxgate principle that meets the requirement had been developed using a ferrite ring core. The ferrite ring core is excited by an excitation current source to achieve hysteresis condition. The pick up coil that is wound across the ring core will pick up the magnetic flux generated in the ring core. This sensing method is based on the conventional type of fluxgate magnetometer with detection of second harmonics by a phase sensitive detector. Major advantages of the fluxgate magnetometer are low cost, directional, easy to construct, reliable and rugged. Key words: Fluxgate; magnetic sensor; hysteresis; ferromagnetic

scholarly journals Portable and Highly Versatile Impedance Meter for Very Low Frequency Measurements

2021 ◽  
Vol 11 (17) ◽  
pp. 8234 ◽  
Author(s):  
Graziella Scandurra ◽  
Antonella Arena ◽  
Emanuele Cardillo ◽  
Gino Giusi ◽  
Carmine Ciofi
Keyword(s):  
Low Cost ◽  
Low Frequency ◽  
Impedance Measurement ◽  
Digital Signal ◽  
Low Complexity ◽  
Electrical Impedance Spectroscopy ◽  
Low Frequencies ◽  
Core System ◽  
Very Low Frequency ◽  
Public Domain Software

Electrical Impedance Spectroscopy (EIS) is a characterization technique that is gaining more and more importance in various fields of research and applications. The frequency range of investigation varies according to the type of application. In some fields (biology, medicine, energy) it is useful to be able to perform measurements at very low frequency values (down to a few mHz or even below). While impedance meters operating at frequencies in the range from a few tens of Hz up to a few MHz can be regarded as quite standard pieces of instrumentation commonly available in many laboratories, instrumentation for measurements at very low frequencies, although commercially available, is less common. The subject of this work is the design, realization and testing of a low frequency impedance measurement platform that has the advantage of being portable, rather inexpensive, and yet highly versatile. In our approach, we exploit a personal computer and a soundboard as a powerful system for digital signal generation and analysis that, with the help of low complexity and low-cost external hardware and a public domain software for the implementation of the core system, allow to tailor the platform for targeting specific applications with minimal effort. As an example, we will demonstrate the application of the system to the investigation of polypyrrole-based supercapacitor structures.

Fault Localization of Power-Ground Short via Signal Injection and Oscilloscope Technique

2010 ◽  
Author(s):  
Binh Nguyen
Keyword(s):  
Low Cost ◽  
Short Circuit ◽  
Fault Localization ◽  
Fault Isolation ◽  
Test Apparatus ◽  
Good Working ◽  
Signal Injection ◽  
Set Up ◽  
Non Destructive ◽  
Short Circuit Condition

Abstract For those attempting fault isolation on computer motherboard power-ground short issues, the optimal technique should utilize existing test equipment available in the debug facility, requiring no specialty equipment as well as needing a minimum of training to use effectively. The test apparatus should be both easy to set up and easy to use. This article describes the signal injection and oscilloscope technique which meets the above requirements. The signal injection and oscilloscope technique is based on the application of Ohm's law in a short-circuit condition. Two experiments were conducted to prove the effectiveness of these techniques. Both experiments simulate a short-circuit condition on the VCC3 power rail of a good working PC motherboard and then apply the signal injection and oscilloscope technique to localize the short. The technique described is a simple, low cost and non-destructive method that helps to find the location of the power-ground short quickly and effectively.

scholarly journals The grades and freshness assessment of eggs based on density detection using machine vision and weighing sensor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Supakorn Harnsoongnoen ◽  
Nuananong Jaroensuk
Keyword(s):  
Machine Vision ◽  
Vision System ◽  
Low Cost ◽  
Measuring System ◽  
Coefficient Of Determination ◽  
Water Displacement ◽  
Non Invasive ◽  
Future Potential ◽  
Non Destructive ◽  
Egg Freshness

AbstractThe water displacement and flotation are two of the most accurate and rapid methods for grading and assessing freshness of agricultural products based on density determination. However, these techniques are still not suitable for use in agricultural inspections of products such as eggs that absorb water which can be considered intrusive or destructive and can affect the result of measurements. Here we present a novel proposal for a method of non-destructive, non-invasive, low cost, simple and real—time monitoring of the grading and freshness assessment of eggs based on density detection using machine vision and a weighing sensor. This is the first proposal that divides egg freshness into intervals through density measurements. The machine vision system was developed for the measurement of external physical characteristics (length and breadth) of eggs for evaluating their volume. The weighing system was developed for the measurement of the weight of the egg. Egg weight and volume were used to calculate density for grading and egg freshness assessment. The proposed system could measure the weight, volume and density with an accuracy of 99.88%, 98.26% and 99.02%, respectively. The results showed that the weight and freshness of eggs stored at room temperature decreased with storage time. The relationship between density and percentage of freshness was linear for the all sizes of eggs, the coefficient of determination (R2) of 0.9982, 0.9999, 0.9996, 0.9996 and 0.9994 for classified egg size classified 0, 1, 2, 3 and 4, respectively. This study shows that egg freshness can be determined through density without using water to test for water displacement or egg flotation which has future potential as a measuring system important for the poultry industry.

scholarly journals A phase-locked loop using ESO-based loop filter for grid-connected converter: performance analysis

2021 ◽  
Author(s):  
Baoling Guo ◽  
Seddik Bacha ◽  
Mazen Alamir ◽  
Julien Pouget
Keyword(s):  
Performance Analysis ◽  
Frequency Domain ◽  
Low Frequency ◽  
Experimental Tests ◽  
Frequency Measurement ◽  
Phase Locked Loop ◽  
Frequency Domain Analysis ◽  
Loop Filter ◽  
Control Stability ◽  
Unbalanced Grid

AbstractAn extended state observer (ESO)-based loop filter is designed for the phase-locked loop (PLL) involved in a disturbed grid-connected converter (GcC). This ESO-based design enhances the performances and robustness of the PLL, and, therefore, improves control performances of the disturbed GcCs. Besides, the ESO-based LF can be applied to PLLs with extra filters for abnormal grid conditions. The unbalanced grid is particularly taken into account for the performance analysis. A tuning approach based on the well-designed PI controller is discussed, which results in a fair comparison with conventional PI-type PLLs. The frequency domain properties are quantitatively analysed with respect to the control stability and the noises rejection. The frequency domain analysis and simulation results suggest that the performances of the generated ESO-based controllers are comparable to those of the PI control at low frequency, while have better ability to attenuate high-frequency measurement noises. The phase margin decreases slightly, but remains acceptable. Finally, experimental tests are conducted with a hybrid power hardware-in-the-loop benchmark, in which balanced/unbalanced cases are both explored. The obtained results prove the effectiveness of ESO-based PLLs when applied to the disturbed GcC.

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