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Byggteknikhistoria - några iakttagelser

Genom ett antal artskilda exempel - valda fran det byggnadstekniska området i vid mening - har vi nu försökt belysa några karakteristiska fenomen inom teknikhistorien. Från den inledande beskrivningen av geodesins utveckling har vi kunnat observera den växling, som skett historiskt av denna vetenskaps referensram. I den tidiga historien gav därvid studier av fenomen på jorden underlaget för uppfat

Vascular endothelial growth factor-B-deficient mice display an atrial conduction defect

BACKGROUND: Vascular endothelial growth factors (VEGFs) and their receptors are essential regulators of vasculogenesis and angiogenesis in both embryos and adults. One of the factors with a still unknown physiological function is VEGF-B, which is expressed in many tissues, including the heart. METHODS AND RESULTS: Mice carrying a targeted deletion in the VEGF-B gene were developed. In VEGF-B(-/-)

The Preboreal climate reversal and a subsequent solar-forced climate shift

Accurate chronologies are essential for linking palaeoclimate archives. Carbon-14 wiggle-match dating was used to produce an accurate chronology for part of an early Holocene peat sequence from the Borchert (The Netherlands). Following the Younger Dryas-Preboreal transition, two climatic shifts could be inferred. Around 11 400 cal. yr BP the expansion of birch (Betula) forest was interrupted by a

Barriers to effective implementation of guideline recommendations.

Cardiovascular disease (CVD) is the leading cause of death worldwide, and its prevention and treatment are important healthcare aims. Hypercholesterolemia is among the most important modifiable Rick factors for CVD, and numerous guidelines exist for the treatment of this condition. Nevertheless, despite the existence of well-established and safe pharmacologic therapy for lowering cholesterol and p

Hushållens energianvändning och styrmedelsstrategier

Under decennier har alla samhällssektorer blivit alltmera beroende av tillgång till säkra energileveranser för att kunna utföra sina uppdrag vare sig det gäller företag eller offentlig service och verksamhet. Även hushåll har för sitt vardagsliv blivit beroende av energi för att hålla värme i bostaden, laga mat, tvätt och hygien samt för att orientera sig i omvärlden via radio, TV eller internet.

Ground state and electronic spectrum of Cu(II) and Cu(III) complexes of N,N '-1,2-phenylenebis-2-mercaptoacetamide

The electronic structure and the UV- vis spectrum of reduced and oxidized model systems of the N, N'- 1,2phenylenebis( 2- mercapto- 2- methylpropionamide) copper complex have been studied using a multiconfigurational quantum chemical method ( CASSCF/ CASPT2). The bonds between Cu and the two sulfur ligand atoms have a large covalent character in the oxidized Cu( (III)) form. As a result of the inc

High-repetition-rate, hard x-ray radiation from a laser-produced plasma: Photon yield and application considerations

We present an experimental study of hard x rays produced in laser-produced plasmas. The laser used is a 1 kHz system, delivering 0.7 mJ for 25 fs onto a solid target. The x-ray spectrum was measured with calibrated germanium detectors, allowing a very good estimate of the absolute number of photons emitted from the plasma over a wide energy range; from 7 keV to 0.5 MeV. Assuming a bi-Maxwellian el

Statistical presentation and analysis of ordinal data in nursing research.

Objectives: The aim of this study was to review the presentation and analysis of ordinal data in three international nursing journals in 2003. Method: In total, 166 full-length articles from the 2003 editions of Cancer Nursing, Scandinavian Journal of Caring Sciences and Nursing Research were reviewed for their use of ordinal data. Results: This review showed that ordinal scales were used in abo

On Strategy and Manufacturing Flexibility

The era when customers bought what companies produced is long gone. The situation is now reversed and companies must produce what customers want; while the customers' preferences are, furthermore, becoming increasingly diverse. This has forced companies to adopt a new mode of thinking in order to survive. The strategy, by necessity, has become to manufacture flexibly. This thesis focuses on stra

On the solvation of ions in small water droplets

The solvations of positively and negatively charged model ions in water droplets have been studied using Monte Carlo simulations performed with a polarizable intermolecular potential function model. Special focus has been placed on the position of the ion in the water droplet. It was found that the sign of the ionic charge is of minor importance but an increased ionic charge localizes the ion to t

Dimension product structure of hyperbolic sets

We conjecture that the fractal dimension of hyperbolic sets can be computed by adding those of their stable and unstable slices. This would facilitate substantial progress in the calculation or estimation of these dimensions, which are related in deep ways to dynamical properties. We prove the conjecture in a model case of Smale solenoids.

Förändring, stabilitet, managed competition

Den amerikanska staden Phoenix ligger omgiven av berg i Sun Valley, Arizona. Klimatet är varmt och glest utspridda kaktusar står som eldgafflar mot skyn. Tänk på en typisk Vilda Västern-film så får du en förnimmelse av vad som kännetecknar Phoenix omgivningar. Trots ökenlika förhållanden bor där idag 1,3 miljoner invånare. Befolkningstillväxten tog fart på allvar luftkonditioneringen introducerade

The new septum magnets

In an earlier paper we reported on a new septum magnet design with a magnetic flux filter [1]. Now the first septum magnet is in operation as in injection septum magnet for the MAX I storage ring. We dcscribe the actual mechanical construction and the field measurements of the new magnets. The fine Structure of the septum nose needed several trials in the construction until we found the final solu