Although, the stored electromagnetic energy of an antenna is used to determine the antenna Q, it is difficult to define the stored energy. The stored energy can be estimated from the input impedance of the antenna, the electromagnetic fields around the antenna, and the current densities in the antenna structure. These estimates are similar but not equal for all antennas. Here, the different approa

Present work deals with reducing secondary losses in turbine cascade by using boundary layer fences in two ways. Firstly, to reduce the strength of vortex which is incident at the leading edge of airfoil and hence reduce the strength of horse shoe vortex, and secondly, to reduce the pressure gradient between the pressure side and the suction side in the flow passage region between airfoils. In pre

Kommer vi att drabbas av en "metanbomb" när värmen tinar den ständigt frusna permafrosten och värmer upp våtmarkerna och havet i Arktis? Risken för detta nämns i olika sammanhang, och handlar om att stora mängder metangas – en starkare växthusgas än koldioxid – snabbt skulle kunna frigöras och stiga upp i atmosfären. Klimatologen Markku Rummukainen finner att det kanske inte blir någon explosion,

Research on the teaching and learning of mathematical modelling has attracted an increasing interest during the last 20 years. One concept of special significance in this field of research is the modelling competence, related to and intertwined with other mathematical sub-competences. In this paper some results from the research on the teaching and learning of mathematical modelling are presented

Vad är egentligen ett brottsoffer? I samtal, filmer, berättelser och lagtexter används bilden av offerskap på olika sätt. Yrkesutövare, frivilligarbetare på brottsoffer- och kvinnojourer, lagstiftare och andra söker bl a genom denna tillskrivning skapa sympati eller mobilisera fördömanden genom att understryka eller nedtona ansvar, lidande eller det behjärtansvärda, det modiga eller det dumdristig

The benefits of archaeology are seldom discussed in relation to the evident fascination of many people with the subjects of archaeology and the past. This current popularity of a certain way of perceiving archaeology and the past can be seen as a part of larger trends associated with the Experience or Dream Society as described by scholars such as Gerhard Schulze and Rolf Jensen. In this paper, I

Correct time and frequency synchronization is important for the performance of orthogonal frequency division multiplex (OFDM) systems. We evaluate a system where a pseudonoise sequence (PN-sequence) is used for estimation of these synchronization parameters. The PN-sequence is superimposed on the OFDM signal. The system is evaluated by means of the variance of the frequency estimation error and th

The paper presents TrueTime, aMatlab/Simulink-based simulator for real-time controlsystems. TrueTime makes it possible to simulate the temporalbehavior of multi-tasking real-time kernels containing controllertasks and to study the effects of CPU and network scheduling on controlperformance. The simulated real-time kernel is event-driven and canhandle external interrupts as well as fine-grained det