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The dynamical processes associated with electric field manipulation of the polarization in a ferroelectric remain largely unknown but fundamentally determine the speed and functionality of ferroelectric materials and devices. Here we apply subpicosecond duration, single-cycle terahertz pulses as an ultrafast electric field bias to prototypical BaTiO3 ferroelectric thin films with the atomic-scale
The European Space Agency's Gaia satellite was launched into orbit around L2 in December 2013 with a payload containing 106 large-format scientific CCDs. The primary goal of the mission is to repeatedly obtain high-precision astrometric and photometric measurements of one thousand million stars over the course of five years. The scientific value of the down-linked data, and the operation of the on
Olof von Dalin (1708–1763) är en skepnadsskiftande person och diktare. I sina texter anlägger han gärna masker, talar genom främmande, uppdiktade munnar. Dalin är inte bara en författare, utan många. Han anteciperade Bellman, som i likhet med sin förebild Dalin gav liv åt olika karaktärer och talade och sjöng med olika poetiska tonfall. Dalin är både pekoralpastischens upphovsman i Sverige och den
»Märket» på svensk arbetsmarknad innebär att exportindustrins löneöverenskommelse fungerar som norm för alla andra avtal. Det är ett omstritt system, men trots detta vet vi mycket lite om dess uppkomsts. I den här texten dyker ekonomhistorikern Erik Bengtsson djupt ner i källorna för att hitta bakgrunden till systemet, och finner att tidigare forskning haft fel i antagandet om att en lönepolitik l
Context. As part of the data processing for Gaia Data Release 1 (Gaia DR1) a special astrometric solution was computed, the so-called auxiliary quasar solution. This gives positions for selected extragalactic objects, including radio sources in the second realisation of the International Celestial Reference Frame (ICRF2) that have optical counterparts bright enough to be observed with Gaia. A subs
We discuss the generalized Rice formula approach to deriving long-run distributions of characteristics defined at random events of a stochastic process or field. The approach stems from the same principle originally introduced by Rice for the level crossing intensity in a random signal and we review its extensions to more general contexts. Events are defined on random surfaces through crossing lev
When implementing a language by means of attribute grammars, it is often useful to study example programs and their attributed trees, to understand the compiler structure, or for debugging. DrAST is a tool that allows interactive inspection of attributed trees. It is interfaced to the JastAdd metacompiler, and supports all JastAdd attribution mechanisms, such as demand evaluation, reference attrib
Et af de mest interessante spørgsmål en fysiker kan forsøge at svare på er hvad består tingene af?. Et hus kan skilles ad i mursten, og murstenen kan også skilles ad i sine bestanddele.Sådan kan man fortsætte indtil man bare har atomer tilbage. Atomerne kan skilles ad ielektroner og en atomkerne der består af neutroner og protoner. Elektronen er, så vidt vived, fundamental, og kan ikke skilles ad.This thesis concerns models of high energy collisions of sub-atomic particles, and the models’ implementation in numerical simulations; so–called Monte Carlo event generators. The models put forth in the thesis improves the description of soft collisions of protons, and takes the first steps towards a new, microscopic description of collectivity in proton collisions and collisions of heavy nuclei
A method of measuring three-dimensional spatial wave size is proposed and statistical distributions of the size characteristics are derived in explicit integral forms for Gaussian sea surfaces. New definitions of wave characteristics such as the crest-height, the length, the size and the wave front location are provided in fully dimensional context. The joint statistical distributions of these wav
Braided convolutional codes (BCCs) are a class of spatially coupled turbo-like codes (SC-TCs) with excellent belief propagation (BP) thresholds. In this paper we analyze the performance of BCCs in the finite block-length regime. We derive the average weight enumerator function (WEF) and compute the union bound on the performance for the uncoupled BCC ensemble. Our results suggest that the union bo
Purpose: Various food patterns have been associated with weight change in adults, but it is unknown which combinations of nutrients may account for such observations. We investigated associations between main nutrient patterns and prospective weight change in adults. Methods: This study includes 235,880 participants, 25–70 years old, recruited between 1992 and 2000 in 10 European countries. Intake
This article presents a first attempt to investigate the news content and news routines of Danish and Swedish news media covering the Öresund region. From a theoretical perspective, the Öresund region can be considered a possible best-case example of what is categorised as horizontal Europeanisation, in other words, of the potential for increased communication linkages in news media content among This article presents a first attempt to investigate the news content and news routines of Danish and Swedish news media covering the Öresund region. From a theoretical perspective, the Öresund region can be considered a possible best-case example of what is categorised as horizontal Europeanisation, in other words, of the potential for increased communication linkages in news media content among
High-resolution pionic atom X-ray spectroscopy was performed with an X-ray spectrometer based on a 240 pixel array of superconducting transition-edge sensor (TES) microcalorimeters at the φM1 beam line of the Paul Scherrer Institute. X-rays emitted by pionic carbon via the 4f → 3d transition and the parallel 4d → 3p transition were observed with a full width at half maximum energy resolution of 6.
Idag används årligen över 2 miljoner ton bekämpningsmedel (BM) i världen. Avdessa står Sverige för drygt 9000 ton, eller knappt en halv procent. Den häravhandlingen handlar om att ta fram metoder för att bestämma rester av vissabekämpningsmedel i kroppsvätskor (urin) hos människor och sedan användametoderna för att mäta exponering för bekämpningsmedlen i en befolkningsgrupp. Arbetet är en del av fAlmost every human is exposed to pesticides, in work environments, by domestic use and via diet, drinking water and personal products. Current research expresses concern that low dose exposure over time can lead to adverse health effects. It is therefore important to biomonitor exposure to pesticides in different groups, especially vulnerable groups such as pregnant women. However, there is a gene
Short and intense XUV pulses are important tools to study ultrafast dynamics and non-linear processes in matter. These pulses can be generated by free electron lasers (FELs) or by high-order harmonic generation (HHG), which are two complementary techniques. The advantage of HHG is the possibility to generate pulses with durations on the attosecond timescale, but the low conversion efficiency of th
