Transducer for Measuring the Flow Rate of Fuel in the Manned Transport Spacecraft Soyuz
A fuel flow rate transducer design for a manned transport spacecraft is proposed. It is based on the principle of measuring the phase of the useful signal carrier frequency. This scheme significantly improves the stability of the instrument against mechanical interactions and provides more accurate measurements of the amount of fuel consumed by the spacecraft.
This handbook presents a set of calculated analytical formulas for determining the basic electrophysical parameters of electronic equipment: electrical capacity, inductance and wave impedance. These parameters play an essential role in ensuring the signal integrity and power integrity of electronic equipment and its electromagnetic compatibility. It is especially important to have design ratios when designing transmission lines on printed circuit boards or in wiring with a given characteristic impedance. It is very important for developers and designers to obtain operational estimates of parameters in the early stages of design, which is possible using this handbook. The analytical expressions provided in it provide accuracy that is acceptable for engineering practice. Each formula in the reference book is accompanied by tables with the results of calculations in a certain range of parameter values, the corresponding graphs and comments that allow you to gain experience in the physical interpretation of the results. For the most cumbersome analytical expressions, alternative compact expressions based on various approximations are proposed. This greatly simplifies the calculation. The reference book is aimed at a wide range of specialists involved in the design of electronic equipment and printed circuit boards; it will be useful for practicing engineers who are engaged in the design of technical equipment
This article considers the possibility of expanding the operating band of “chain of coupled resonators”-type slow-wave structure. A waveguide-resonator model which allowed to determine the conditions of the main passband expansion and the coupling impedance increase is utilized.
A method of antenna element coupling control using a readjust of the surface impedance of the plane, it is mounted, is shortly described. A construction of a tunable frequency-selective metamaterial-made surface, which is designed to be a patch antenna element ground plane, is presented. Results of antenna VSWR measurements, which show the coupling change correspondingly the antenna ground plane surface impedance tuning, are shown.
Objectives: BeWo cells are used for the construction of in vitro models of placental barrier. Only the early placenta possesses multiple trophoblast layers whereas third-trimester placenta consists of a single trophoblast layer. BeWo cells do not undergo contact growth inhibition and form multilayer structures. It is important to control the cell state for transport experiments. Impedance spectroscopy was applied for electrical characteristic studying during BeWo cell growth and in response to HIF-1 activator.
Methods: 30,000 cells per insert were seeded into a 96-well Transwell plate (1 μm pore size). After 48 h a potent HIF-1 activator D014-0021 was added at 10 μM concentration. Impedance spectra were acquired with impedance spectroscopy system (Bioclinicum, Russia). For the extraction of electrical parameters, the equivalent electrical circuits were used. Student's t-test was used to calculate the statistical significance.
Results: It was predicted from the mathematical model that medium resistance (Rmed) and the radius of the impedance hodograph (and hence TEER) will rise linearly with the number of layers. In the case of one layer, the radius can rise due to the formation of tight junctions but the Rmed should remain stable, but the data shows increasing TEER and Rmed. There is a statistically significant difference in Rmed between 48 and 96 h. It can be concluded that after 48 h the BeWo cells form multilayer structures. The addition of D014-0021 leads to a slight increase in TEER after 6 h and a significant decrease in TEER and capacitance after 27 h.
Conclusion: It was shown that formation of multilayer structures can be readily detected with impedance spectroscopy and hence it can be used for quality control of the in vitro placental models. It is possible to use impedance spectroscopy for detection of additional parameter changes such as electrical capacitance.
This work is supported by the Russian Science Foundation (project No. 16-19-10597).