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

Experiments were performed on the central body rich-pilotlean (RPL) burner of a Siemens Industrial Turbomachinary 4th generation DLE combustor to observe the combustion changes that may occur when using fuels other than natural gas. Measurements were taken of temperatures at multiple points along the RPL body while hydroxyl (OH) radical distribution extending from the dump plane of the burner was

The burial and gathering site Almhov was discovered as a result of large-scale archaeological excavations in southern Sweden revealing the remains of five long barrows, two dolmens and a large number of pits, rich in finds. Given the multitude of activities performed at the site including, for example, monument-building, pit-digging, burying, feasting and axe-manufacturing, the site can serve as a

Random amplified polymorhic DNA (RAPD) is a PCR-based marker system that makes use of universal sets of short oligonucleotides that amplify random DNA fragments under low-stringency conditions. The RAPD marker system has found widespread use and possesses a number of very positive features, being a multiplex and universal system. The present studies characterize and evaluate the properties of the

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