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We have calculated a random-phase-approximation-type expression for the dielectric response function of several large-band-gap insulators using a development of the model suggested by Fry. This model should be good for systems with well-localized valence-electron functions and flat valence-electron bands. We show that in this model it is a minor approximation to use spherically symmetric bands in

The environmental problems caused by human interventions, such as the consumption of non-renewable resources and the emission of greenhouse gases are well-recognised. Calls have been made for immediate measures to develop more sustainable society worldwide. Attention has also been devoted to the quest for sustainability within the field of chemistry. The concept of “green chemistry” is being intro

Fumigation was studied in a 12 L six-cylinder heavy-duty engine. Port-injected ethanol was ignited with a small amount of diesel injected into the cylinder. The setup left much freedom for influencing the combustion process, and the aim of this study was to find operation modes that result in a combustion resembling that of a homogeneous charge compression ignition (HCCI) engine with high efficien

This paper presents low power hardware generation, based on a CAL actor language dataflow implementation. The CAL language gives a higher level of abstraction and generate both hardware and software description. The original CAL flow is targeted for hardware-software co-design of complex systems on FPGA. Modifications are done to the original CAL flow to facilitate low power ASIC implementations.

Gear hobbing is well established and one of the most cost effective manufacturing methods of involute gears. In the hobbing of lead crown corrected helical gears, a well know drawback is the non-uniform systematic tooth alignment deviation that arises. This is sometimes denoted as flank twist. The inevitable tooth alignment deviation, together with other source deviations, must not exceed the spec

Abstract not available

Hur kan undervisningen i informationskompetens utvecklas för att underlätta ett djupare lärande? Här belysses detta utifrån ett lektionsmoment som behandlar källkritiska aspekter, något som med fördel kan integreras mer i studenternas ämneskontext, t.ex. genom att förankra det i typiska källor och material för ett visst ämnesområde.

Bakgrund Allt fler människor ägnar allt mer tid och pengar åt tv- och datorspel. Att spela, vare sig det handlar om att raida i World of Warcraft, bowla tillsammans med svärföräldrarna i Wii Sports eller att köra en snabb omgång Bejeweled under en kaffepaus på jobbet, har blivit en del av det dagliga livet för miljontals människor oavsett ålder, kön och bakgrund. Spel och vardagsliv kombineras på