University of Maribor

About: University of Maribor is a education organization based out in Maribor, Slovenia. It is known for research contribution in the topics: Population & KEKB. The organization has 3987 authors who have published 13077 publications receiving 258339 citations. The organization is also known as: Univerza v Mariboru.

Capillary absorption in concrete and the Lucas–Washburn equation

Abstract: Capillary absorption kinetics of concrete–ethylene glycol system was studied with respect to concrete matrix porosity and liquid viscosity. Porosity of specimens was altered by air-entraining agents and superplasticizers. Liquid which doesn’t react with cement gel was chosen for the experiment in order to study the reasons for deviation from Lucas–Washburn equation observed in concrete–water system. Viscosity of ethylene glycol changes from ∼23 to 2 mPa s in the temperature range from 20 to 100 °C. The values of the capillary coefficient were determined at 20, 60 and 100 °C using Neutron Radiography and were found to be in the range from ∼1.5 to 4.9 mm h −1/2 . The results show that the Lucas–Washburn equation in concrete–ethylene glycol system is valid only for ∼25 h, which indicates that swelling and rehydration of cement gel are not the main reasons for deviation observed in concrete–water system.

Analysis of iron loss in interior permanent magnet synchronous motor over a wide-speed range of constant output power operation

Abstract: The paper presents the analysis of iron loss in interior permanent magnet synchronous motor over a wide-speed range of constant output power operation. The analysis is based on finite element method and uses the information on local flux density variation in the motor components. The total iron loss is calculated by summing up separately the hysteresis, classical eddy current and excess losses for each element of discretization over one electrical cycle of magnetic field variation in all parts of motor iron. The results of iron loss calculation were compared with the results obtained from experiments on the actual machine.