Search results

Filter

Filetype

Your search for "*" yielded 532314 hits

Multilocus species trees show the recent adaptive radiation of the mimetic heliconius butterflies

Müllerian mimicry among Neotropical Heliconiini butterflies is an excellent example of natural selection, associated with the diversification of a large continental-scale radiation. Some of the processes driving the evolution of mimicry rings are likely to generate incongruent phylogenetic signals across the assemblage, and thus pose a challenge for systematics. We use a data set of 22 mitochondri

Polymer Mediated Surface Forces

The issue of controlling the stability between colloidal particles in solution is important, at least for industrial applications, relying on efficient flocculation or stable dispersions. The objective of this thesis is to shed some light on fundamental mechanisms behind the interplay between attractive and repulsive forces, in solutions containing colloids and polymers. We approach the probl

The American Way? Swedish-American returnees in local Swedish politics during the 1920s

Swedish emigration to America is a topic that does not hold a major position in Swedish historical research anymore. At one time, during the 1960s and 1970s, there were a major research project, Sweden and America after 1860, that focused primarily on the reasons of the migration, the demographics of the migration and to some extent what happened to the emigrants in America. The research project d

Coverage- and temperature-dependent site occupancy of carbon monoxide on Rh(111) studied by high-resolution core-level photoemission

High-resolution core-level photoemission is used to study structural aspects for the molecular adsorption of CO on the Rh(111) single-crystal surface, and in particular to derive the adsorption sites. The site sensitivity of the core-level binding energy and the fact that the core level photoemission signal is proportional to the adsorbate coverage make it possible to study quantitatively how the

Adaptive radiations in butterflies : Evolutionary history of the genus Erebia (Nymphalidae: Satyrinae)

We studied the speciose butterfly genus Erebia by reconstructing its phylogenetic relationships using parsimony and Bayesian approaches. We estimated times and rates of diversification for its lineages and employed a biogeographical analysis in order to reconstruct its evolutionary history. DNA sequence data from one mitochondrial gene and three nuclear genes were analyzed for a total of 74 specie

Chemical characterization of cyanogen bromide fragments from the beta-chain of human complement factor C3

The isolated beta-chain of human complement factor C3 (C3 beta) was fragmented by cyanogen bromide. Nine fragments were defined by gel filtration and high-pressure liquid chromatography, and characterized with respect to their Mr, amino acid composition and N-terminal amino acid sequence. Approx. 30% of the primary structure of C3 beta was determined. Alignment of the 3 N-terminal fragments allowe

On Reduction of Production Disturbances in Manufacturing Systems Based on Discrete-Event Simulation

Popular Abstract in Swedish Förbättrad effektivitet i tillverkningssystemen för att åstadkomma förbättrad output och sålunda reducera tillverkningsstörningarna är ett viktigt område. Händelsestyrd simulering kan visualisera och studera de dynamiska förloppen relaterade till total effektivitet i tillverkningssystemen. En metodik för reducering av produktionsstörningar är presenterad. Förbättringar Improved efficiency in manufacturing systems to achieve increased output and thus reduced production disturbances is a vital area. DES (Discrete-Event Simulation) can visualize and study the dynamic issues related to total efficiency in manufacturing systems. A methodology for production disturbance reduction is presented. Increased performance of manufacturing systems means not only enhanced valu

Numerical quantification of water saturation, back diffusion, electro-osmotic drag and water generation in polymer electrolyte membrane fuel cells

A 3D unit cell has been simulated numerically using a commercial software in order to evaluate and quantify various water related phenomena, i.e., electro-osmotic drag, back diffusion, electro-chemical water generation and the saturation effects in the porous media. The water saturation effects were noticed to be more pronounced in the GDL of the cathode as compared to the catalyst layer due to gr