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Number of results: 9
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Abstract

In this study the results of simultaneous measurements of dynamic viscosity, thermal conductivity, electrical conductivity and pH of two nanofluids, i.e., thermal oil/Al2O3and thermal oil/TiO2are presented. Thermal oil is selected as a base liquid because of possible application in ORC systems as an intermediate heating agent. Nanoparticles were tested at the concentration of 0.1%, 1%, and 5% by weight within temperature range from 20°C to 60°C. Measurement devices were carefully calibrated by comparison obtained results for pure base liquid (thermal oil) with manufacturer’s data. The results obtained for tested nanofluids were compared with predictions made by use of existing models for liquid/solid particles mixtures.
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Authors and Affiliations

Janusz T. Cieśliński
Katarzyna Ronewicz
Sławomir Smoleń
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Abstract

Self-control is a complex and multifaceted construct that can be regarded as an individual trait that follows its own developmental trajectory. In the presented study we used NAS-50 for the assessment of self-control in adolescents and young adults. Since the questionnaire has not been used before in underage participants we tested its reliability in adolescent and adult samples. We also investigated possible age and gender differences in self-control abilities as well as relations between NAS-50 and behavioral measures of cognitive control and impulsivity. Although the sample was quite small, the reliability of the questionnaire was similar to the results achieved by its authors. According to the predictions in the literature we did not find relations between NAS-50 and behavioral measures of cognitive control and impulsivity. We also did not observe significant age differences in the assessment of self-control abilities. The theoretical relevance of our results is discussed.

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Authors and Affiliations

Joanna Fryt
Tomasz Smoleń
Karolina Czernecka
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Abstract

The paper discusses in detail the construction of the Core Less Axial Flux Permanent Magnet generator simulation model. The model has been prepared in such a way that full compatibility with the elements of the SimPowerSystem library of the Matlab/Simulink package is preserved, which allows easy use of the presented simulation model for testing the work of the generator as part of a larger system. The parameters used in the model come from the MES 3D calculations performed in the Ansys/Maxwell software, for a machine prototype with a rated power of 2.8 kW, which was then used to experimentally verify the correct operation of the presented model of machine.

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Authors and Affiliations

Marek Gołębiowski
Andrzej Smoleń
Lesław Gołębiowski
Damian Mazur
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Abstract

This paper is focused on the manufacturing and properties of light weight aggregates made from local waste materials. The waste materials were car windshield glass contaminated by PVB foil, fly ash, mine slates as well as wastes after toothpaste production. The main aim of the research was to combine car windshield glass and the aluminosilicate coal mine slates as a basis for light weight aggregates manufacturing. Fly ash were added in order to modify rheological properties of the plastic mass. Toothpaste wastes were introduced as a source of carbonates and CO2 evolution during thermal treatment. After milling and mixing all materials they were pressed and sintered at temperature range of 950°C-1100°C in air. The results show that it is possible to receive light weight aggregates only from the Silesian local waste materials. The significant influence of sintering temperature on properties of aggregates was observed.

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Authors and Affiliations

J. Smoleń
T. Pawlik
M. Sopicka-Lizer
D. Michalik
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Abstract

Although there are many methods and instruments for measuring viscosity, it is still difficult to determine a reliable value of the dynamic viscosity of complex chemicals such as paraffins and fatty acids. This is due to the complex and heterogeneous structure of these compounds in the case of commercial products. On the other hand, the measuring instrument should be selected very carefully, including its measuring principle and measuring range. This paper presents results of viscosity measurements of three organic PCMs (phase change materials) obtained in four different research institutions. Commercial products: paraffin, myristic acid (97%) and mixture of palmitic acid (55%) and stearic acid (45%) were selected as PCMs. Four different viscometers, namely Fungilab V-Pad, Rheotest LK 2.2, Rheometer Anton Paar MCR 102, and Brookfield DV-II + Pro have been used to determine temperature dependent dynamic viscosity of the tested PCMs. Using a large database of present measurement results, correlations were developed to calculate the dynamic viscosity of fatty acids and paraffins, which predict the experimental data within a band of ±20%.
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Authors and Affiliations

Janusz Tadeusz Cieśliński
1
Maciej Fabrykiewicz
1
Tomasz Stefan Wiśniewski
2
Michał Kubiś
2
Sławomir Smoleń
3
Albrecht Eicke
3
Krzysztof Dutkowski
4
Małgorzata Głuszek-Czarnecka
5

  1. Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
  2. Warsaw University of Technology, Nowowiejska 21/25, 00-665 Warsaw, Poland
  3. Hochschule Bremen, JR Mayer-Institut für Energietechnik, Neustadswall 30, 28199 Bremen, Germany
  4. Koszalin University of Technology, Racławicka 15-17, 75-620 Koszalin, Poland
  5. Smart Fluid Inc., Rydygiera 8/20A, 01-793 Warsaw, Poland

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