scholarly journals An Adaptive Measurement System for the Simultaneous Evaluation of Frequency Shift and Series Resistance of QCM in Liquid

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 678
Author(s):  
Ada Fort ◽  
Enza Panzardi ◽  
Valerio Vignoli ◽  
Marco Tani ◽  
Elia Landi ◽  
...  

In this paper, a novel measurement system based on Quartz Crystal Microbalances is presented. The proposed solution was conceived specifically to overcome the measurement problems related to Quartz Crystal Microbalance (QCM) applications in dielectric liquids where the Q-factor of the resonant system is severely reduced with respect to in-gas applications. The QCM is placed in a Meacham oscillator embedding an amplifier with adjustable gain, an automatic strategy for gain tuning allows for maintaining the oscillator frequency close to the series resonance frequency of the quartz, which is related in a simple way with the physical parameters of interest. The proposed system can be used to monitor simultaneously both the series resonant frequency and the equivalent electromechanical resistance of the quartz. The feasibility and the performance of the proposed method are proven by means of measurements obtained with a prototype based on a 10-MHz AT-cut quartz.

Author(s):  
Andrey S. KIRILLOV ◽  
Aleksandr P. PYSHKO ◽  
Andrey A. ROMANENKO ◽  
Valery I. YARYGIN

The paper describes an overview of the history of development and the current state of JSC “SSC RF-IPPE” reactor research and test facility designed for assembly, research and full-scale life energy tests of space nuclear power plants with a thermionic reactor. The leading specialists involved in development and operation of this facility are represented. The most significant technological interfaces and upgrade operations carried out in the recent years are discussed. The authors consider the use of an oil-free pumping system as part of this facility during degassing and life testing. Proposed are up-to-date engineering solutions for development of the automated special measurement system designed to record NPP performance, including volt-ampere characteristics together with thermophysical and nuclear physical parameters of a ground prototype of the space nuclear power plant. Key words: reactor research and test facility, thermionic reactor, life energy tests, oil-free pumping system, automated special measurement system, volt-ampere characteristics.


2020 ◽  
Vol 3 (6) ◽  
pp. 5687-5697 ◽  
Author(s):  
Roto Roto ◽  
Aditya Rianjanu ◽  
Annisa Rahmawati ◽  
Innas Amaliya Fatyadi ◽  
Nursidik Yulianto ◽  
...  

Author(s):  
Diego Scaccabarozzi ◽  
Bortolino Saggin ◽  
Marianna Magni ◽  
Pietro Valnegri ◽  
Marco Giovanni Corti ◽  
...  

2011 ◽  
Vol 64 (9) ◽  
pp. 1256 ◽  
Author(s):  
Miroslava Polreichova ◽  
Usman Latif ◽  
Franz L. Dickert

Mass sensitive sensors were applied for fast and label-free detection of bio-analytes. Robust and miniaturized sensor devices were fabricated by combining bio-mimetic imprinted surfaces with quartz crystal microbalances for the analysis of yeast and bacteria cells. These sensors allow us to differentiate between different growing stages of yeast cells. Moreover, the viability of cells was detected by structuring quartz crystal microbalance electrodes like a grid. Artificial yeast cells were produced to pattern the recognition layer, giving reversible enrichment of the respective bio-analytes. This approach was followed to ensure the reproducibility of the identical sensitive material in each case, because the properties of each cell depend on its growth stage, which varies over time. The strategy was further applied to develop a sensitive system for Escherichia coli. Structuring of these materials by soft lithography allows differentiation between cell strains, e.g. E. coli (strain W & B) with a five-fold selectivity.


2010 ◽  
Vol 636-637 ◽  
pp. 1206-1211
Author(s):  
Paulo Inácio ◽  
J.N. Marat-Mendes ◽  
Eugen R. Neagu ◽  
C.J. Dias

Most piezoelectric gravimetric biosensors are based on quartz crystal microbalances or surface acoustic wave devices. In this paper we describe a polymer film system, made of piezoelectric polyvinylidene difluoride (PVDF) and the Immobilon-P membrane (porous PVDF), for biosensing applications. In operation a film is accommodated in a flow cell and connected to an electronic circuit, constituting an oscillatory resonant device; the output signal is its resonance frequency. This device successfully detected the binding between bovine IgG and bovine anti-IgG. Work on the modelling of this film system is presented. Two different approaches are being considered: the finite element method (FEM) and the ABCD matrices. Results comparing theoretical and experimental data are presented.


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