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Niemczewski B.,Polish Tele and Radio Research Institute
Transactions of the Institute of Metal Finishing | Year: 2011

The purpose of the work was to compare cavitation intensities of solutions of various salts with cavitation of water in order to identify that some solutions cavitate more intensely than water and this might be applied in practice. Cavitation intensities at an ultrasonic frequency of 26 kHz in tap water and in thirty-five 3% aqueous solutions of selected inorganic salts were compared, as well as in tap water and in twenty-four 3% solutions of inorganic salts at 38 kHz and at 50°C. It was found that at 38 kHz many salt solutions cavitate more intensely than water and some of them cavitate considerably more intensely. At 26 kHz only one such salt was found. At both frequencies and 50°C, some of salt solutions cavitate much less intensely than water. © 2011 Institute of Metal Finishing.


Lesniewska E.,University of Lodz | Lisowiec A.,Polish Tele and Radio Research Institute
IEEE Transactions on Power Delivery | Year: 2016

High accuracy is required from devices operating in the measuring and protection systems of transmission lines during the transformation of signals. Their immunity to external fields is very important because it has a direct influence on the proper functioning of the protection system. In this paper, the electromagnetic current-to-voltage transducers, with coils designed and manufactured using a multilayer high-density interconnect printed-circuit board technology, are presented. The analysis of the influence of the external magnetic field caused by other devices on the proper functioning of the current-to-voltage transducer has been presented. The analysis of the electromagnetic-field distributions has been carried out using the 3-D field-circuit method based on the finite-element numerical method. The magnetic-field distributions and the induced secondary voltages for several different applications have been presented. The results have been compared with tests of real-life models. © 2015 IEEE.


Niemczewski B.,Polish Tele and Radio Research Institute
Transactions of the Institute of Metal Finishing | Year: 2010

Maximum cavitation intensities at 60°C of 3% aqueous solutions of chemical substances used as components of media for ultrasonic cleaning in aqueous alkaline solutions have been measured. The maximum cavitation intensities for these substances reached in 25 and 40 kHz cleaners have been compared. © 2010 Institute of Metal Finishing.


Hryniewicz T.,Koszalin University of Technology | Konarski P.,Polish Tele and Radio Research Institute | Rokicki R.,Electrobright | Valicek J.,VSB - Technical University of Ostrava
Surface and Coatings Technology | Year: 2012

Hydrogenation of the commercial purity (99%) CP Titanium Grade 2 biomaterial was investigated using the secondary ion mass spectrometry (SIMS) after two finishing electrochemical operations: standard electropolishing (EP), and magnetoelectropolishing (MEP). The SIMS depth profile analyses were carried out right after electropolishing, and again one month later. The mass spectrograms of secondary positive and negative ions were recorded. SIMS spectra reveal higher emission of positive O +, Ti + and TiO + secondary ions which corresponds to higher oxidation of MEP sample. Negative spectra show higher concentration of compounds containing carbon on MEP sample than those of EP sample. Lower content of hydrogen in the near-surface layers in the MEP sample right after the process was revealed. It was found that the concentrations of oxygen and hydrogen alter in time. One month of storage in air causes the contents of hydrogen in EP and MEP samples to be equalized. The SIMS studies performed after a one month period show that the differences in hydrogen contents between EP and MEP samples are not significant. © 2012 Elsevier B.V.


Czopik A.,Polish Tele and Radio Research Institute
Welding International | Year: 2013

This paper presents the application of an electron beam as a tool for welding metals, and discusses new opportunities for its use based on the use of a computer control system. © 2013 Copyright Taylor and Francis Group, LLC.

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