Search results

Heat transfer losses are one of the largest loss contributions in a modern internal combustion engine. The aim of this study is to evaluate the contribution of the piston bowl type and swirl ratio to heat losses and performance. A commercial CFD tool is used to carry out simulations of four different piston bowl geometries, at three engine loads with two different swirl ratios at each load point.

The excavations of one of the plots in the Black Earth at Birka revealed an unusually large number of objects associated with long-distance eastern contacts. Among the objects was a Volga Bulgarian pot and a hoard containing Volga Bulgarian imitations of dirhams. The surprisingly high proportion of Volga Bulgarian coins in the hoard indicates that the person(s) who lived on the plot in the mid ten

The generalized Pareto distribution (GPD) is a two-parameter family of distributions which can be used to model exceedances over a threshold. We compare the empirical coverage of some standard bootstrap and likelihood-based confidence intervals for the parameters and upper p-quantiles of the GPD. Simulation results indicate that none of the bootstrap methods give satisfactory intervals for small s

This chapter is intended as a background on natural photosynthesis for those interested in artificial photosynthesis. It describes how light is used for creating positive and negative charges, and how these charges are transferred through the molecular assemblies in the membranes. Next, the chapter also describes how the charge transport leads to creation of a pH difference across the photosynthet

Bone and soft tissue tumors (BSTT) belong to a diverse group of solid tumors of mesenchymal origin, with a large number of histological types affecting individuals of all ages. The general aim of the present thesis (Articles I-V) was to investigate in detail the genetic aberrations in selected subtypes of benign and malignant BSTT. Aberrations identified by chromosome banding analysis were studied

The sensitivity of biosensors can be increased substantially by incorporation in a substrate recycling scheme. Based on the amplification of NAD+/NADH by the recycling reaction catalyzed by glycerol dehydrogenase (GDH) and diaphorase, NAD+/NADH can be determined amperometrically with around 1000 times higher sensitivity than for the substrate sensing mode. The sensitivity of enzyme electrodes were

It has been suggested that physical or social activity is associated with fewer sleep disturbances among elderly people. Women report more sleep disturbances than men, which could indicate a variation in activity patterns between the genders. The aim of this study was to investigate associations between sleep disturbances and leisure activities in men and women (n = 945) aged ≥60 years in a Swedis

The Skellefte district, northern Sweden, is known for the occurrence of 1.89 Ga Palaeoproterozoic volcanogenic massive sulphide (VMS) deposits. The deposits are hosted by the older part of a volcanosedimentary succession, which was intruded at 1.88-1.86 Ga by multiple phases of the syn-volcanic, early orogenic Jorn intrusive complex (JIC). The oldest phase of the JIC hosts different styles of mine

We report on the first observation of the macroscopic (long-range) phase separation in Si-rich oxide SiOx(x<2) obtained by continuous-wave laser annealing of free-standing SiOx films. The effect is analyzed by a unique combination of microscopic methods (Raman, transmission, photoluminescence, and infrared spectroscopy, transmission electron microscopy, electron energy loss spectroscopy, and x-ray

Embryonic genome activation (EGA) is the first major step towards successful initiation of preimplantation development, which culminates in the formation of implantation-competent embryos. EGA occurs at species-specific embryonic cell stages. In the present work, EGA was identified for buffalo embryos by studying the development rate of embryos in normal as well as imposed transcription block cond

Immune-regulated pathways influence multiple aspects of cancer development. In this article we demonstrate that both macrophage abundance and T-cell abundance in breast cancer represent prognostic indicators for recurrence-free and overall survival. We provide evidence that response to chemotherapy is in part regulated by these leukocytes; cytotoxic therapies induce mammary epithelial cells to pro

We study the curvature of manifolds which admit a complex-valued submersive harmonic morphism with either, totally geodesic fibers or that is holomorphic with respect to a complex structure which is compatible with the second fundamental form. We also give a necessary curvature condition for the existence of complex-valued harmonic morphisms with totally geodesic fibers on Einstein manifolds.