scholarly journals Experimental Measurement of a UAV Propeller's Thrust

2022 ◽  
Vol 29 (1) ◽  
1986 ◽  
Vol 18 (11) ◽  
pp. 131-140
Author(s):  
Edmundo Garcia Agudo ◽  
Jose Leomax dos Santos

The final disposal of sewage using submarine outfalls has become an actual solution for coastal cities all over the world. In order to get the best results it is necessary to carry out specific studies for the proper design of the outfall. Dilution and decrease in bacterial concentrations are two key aspects for the design. Radioisotope tracers have been used extensively in studies performed in some Brazilian waterbodies where outfall systems exist or are to be installed. As far as dilution measurement is concerned, both point and continuous radiotracer injections can provide useful results. The T90 measurements can be better accomplished using a combined tracer technique for sampling the sewage field, using the radiotracer for dilution measurement and rhodamine B as a visual aid. Typical results of dilution measurement using both techniques mentioned, as well as a summary of T 90 results obtained for the Santos, Fortaleza and Maceió outfalls are presented.


1993 ◽  
Author(s):  
Jack H. Winters ◽  
Mario A. Santoro ◽  
Zygmunt Haas

2021 ◽  
Vol 11 (12) ◽  
pp. 5415
Author(s):  
Aleksandr Gorst ◽  
Kseniya Zavyalova ◽  
Aleksandr Mironchev ◽  
Andrey Zapasnoy ◽  
Andrey Klokov

The article investigates the near-field probe of a special design to account for changes in glucose concentration. The probe is designed in such a way that it emits radiation in both directions from its plane. In this paper, it was proposed to modernize this design and consider the unidirectional emission of the probe in order to maximize the signal and reduce energy loss. We have done extensive research for both bidirectional and unidirectional probe designs. Numerical simulations and field experiments were carried out to determine different concentrations of glucose (0, 4, 5.3, 7.5 mmol/L). Numerical modeling of a unidirectional probe showed that the interaction of radiation generated by such a probe with a multilayer structure simulating a human hand showed a better result and high sensitivity compared to a bidirectional probe. Further, based on the simulation results, a phantom (physical model) of a human hand was recreated from layers with dielectric properties as close as possible to the properties of materials during simulation. The probe was constructed from a copper tube and matched both the geometric and physical parameters of the model. The experimental measurement was carried out using a vector network analyzer in the frequency range 2–10 GHz. The experimental measurement was carried out using a vector network analyzer in the frequency range 2–10 GHz for the unidirectional and bidirectional probes. Further, the results of the experiment were compared with the results of numerical simulation. According to the results of multiple experiments, it was found that the average deviation between the concentrations was 2 dB for a unidirectional probe and 0.4 dB for a bidirectional probe. Thus, the sensitivity of the unidirectional probe was 1.5 dB/(mmol/L) for the bidirectional one 0.3 dB/(mmol/L). Thus, the improved design of the near-field probe can be used to record glucose concentrations.


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