Sökresultat

We give a proof of the Nirenberg-Treves conjecture: that local solvability of principal type pseudo-differential operators is equivalent to condition (Psi). This condition rules out sign changes from - to + of the imaginary part of the principal symbol along the oriented bicharacteristics of the real part. We obtain local solvability by proving a localizable a priori estimate for the adjoint opera

On a software development project many people collaborate to build a product contributing different pieces of the final product. Often people on a development team will work in parallel, either on different parts or on the same parts of the product, and follow processes to co-ordinate their work with other people on the team. When teams are distributed this co-ordination becomes more difficult sin

The paper suggests a method for motion generating and stabilization with application to dynamical models for underactuated ships.

Simulation tools are used to a wide extent in the product development process today, both to obtain better products and to reduce the development time required. Anisotropic materials are utilized in many engineering applications. Material models for materials of these types are needed in order to obtain accurate results from the simulations undertaken. In the thesis, a constitutive framework for

The proper handling of alarms is crucial to any automated process control. In practice, many alarms are only distractive and do not represent a fault situation. In an ongoing project a computerized tool is applied, that aims to remove such nuisance alarms, a so-called alarm cleanup. This is a general, systematic approach that takes advantage of the control system's built-in functions, and is a fir

The present thesis analyzes the reform of congregational singing in Livonia and Estonia in the first half of the 19th century. In this process the writings on the aesthetics of the congregational singing of a German pastor Johann Leberecht Ehregott Punschel (1778–1849) active in Livonia, and a chorale book (1839) that he edited occupied the central place. Punschel’s activities are directly associa

Popular Abstract in Swedish För att levande celler ska kunna föröka sig behöver förr eller senare celldelning ske. Detta är en process där en ny cell skapas utifrån den information som finnas lagrad i ursprungscellen. Denna typ av information lagras i cellens DNA. En stor del av DNA:t är ritningar för hur cellens arbetarmolekyler, proteinerna, ska byggas men DNA:t innehåller även information för rIt has been more than 50 years since the enzyme system ribonucleotide reductase (RNR), catalysing the reduction of ribonucleotides to deoxyribonucleotides, was first discovered. RNR was also the first time that radical chemistry was revealed in an enzyme. RNRs carry out a key step in the de novo synthesis of building blocks for DNA and have been found in almost all known organisms. Within this th

Succinate:quinone reductase (SQR) is an enzyme in the respiratory system of aerobic cells. SQR catalyzes two reactions, the oxidation of succinate to fumarate and the reduction of quinone to quinol. These reactions are coupled by electron transfer within the enzyme from the site of succinate oxidation to the site of quinone reduction. Some enzymes reduce ubiquinone (exergonic reaction) whereas oth

Popular Abstract in Swedish Perifer kärlsjukdom (peripheral arterial disease) innebär ett tillstånd med nedsatt blodcirkulation i benen som huvudsakligen beror på åderförkalkning (ateroskleros). De kliniska manifestationerna av perifer kärlsjukdom är fönstertittarsjuka (claudicatio intermittens) och svår cirkulationsnedsättning (kritisk ischemi) beroende på om blodcirkulationen är otillräcklig vidPeripheral arterial disease (PAD) is the manifestation of atherosclerotic lesions in arteries supplying blood to the legs. Atherosclerosis is now recognized as an inflammatory disease of the vessel wall and important features in the pathophysiology are activation of WBC, endothelial cells and increased levels of inflammatory mediators. The inflammatory response in PAD is further influenced in case

A national debate about how to transform and to ‘green’ the problematic housing stocks from the boom era has been going on since the late 1990s. Different kinds of policy instruments with energy efficiency objectives that address either energy systems, energy sources or construction and renovation of the building envelope have been in use. Some policy instruments have combined green objectives wit