Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Stator current spectral content of an induction motor taking into account saturation effect

Harir M., Bendiabdellah A.

Przegląd Elektrotechniczny

2018

R. 94, nr 11

108--112

The work presented in this paper focuses on the spectral content of the stator current in the presence of the saturation effect. To do this, it is necessary to have a mathematical model of the reliable induction machine capable of predicting its behavior in the presence of saturation. The approach of the modified winding function is among the most significant methods because it takes into account the actual distribution of the windings in the stator slots. For this purpose, a series of simulations are carried out to highlight the spectral content of the stator current of the induction squirrel cage motor in the various cases of operation with and without taking into account the saturation effect.

Analizowano charakterystyki widmowe prądu stojana silnika indukcyjnego w stanie nasycenia. Opracowano też model matematyczny silnika umożliwiający przeprowadzenie symulacji. Porównano wyniki symulacji z uzględnieniem nasycenia I bez.

Chemical footprint of the solvent soluble extraterrestrial organic matter occluded in Sołtmany ordinary chondrite

Schmitt-Kopplin P., Harir M., Kanawati B., Tziozis D., Hertkorn N., Gabelica Z.

Meteorites

2012

Vol. 2, No. 1-2

79--92

By characterizing organic molecules of extra-terrestrial origin included in the Sołtmany meteorite, we also present the first results of the non-targeted chemical analysis of the methanol soluble organic matter present in an L6 ordinary chondrite. The structural characterization by means of ultrahigh resolution Fourier transform ion cyclotron mass spectrometry (FT-ICR-MS) with electrospray ionization (ESI) in negative and positive modes demonstrated an unexpected and astonishing chemical diversity with several thousand mass peaks that could be converted into C, H, N, O, S, and P elemental compositions. Molecular signatures were typically those of considerably oxygenated CHO and CHOS molecular series of primarily aliphatic character. 1H nuclear magnetic resonance (NMR) spectroscopy confirmed the prevalent existence of pure and functionalized aliphatic spin systems of intermediate chain length (C3-4 units), oxygenated aliphatics and a considerable diversity of oxygenated aromatics in the proton-based abundance ratio near 24 : 2 : 1. Although only residual organic matter allegedly survives in highly thermally altered L6 chondrites, the physical protection of organic matter in microcavities and traps between mineral surfaces might have supported and governed the chemistry with an apparent recalcitrance of extraterrestrial organic matter (EOM). Future studies of the organic matter in ordinary chondrites and its composition and structure in various regimes of (e.g.) temperature, radiation, pressure, and water content could shed light on these meteorites’ formation and evolution.