Sökresultat

The properties of particle-induced X-ray emission, PIXE, and secondary target mode X-ray fluorescence, XRF, applied to the analysis of unprepared drill cores in open air have been evaluated. Typical detection limits for elements heavier than Mg have been determined for a PIXE-system with an external 2.55 MeV proton beam and for an XRF-system with Ti, Mo and Tb secondary targets. These two systems

A preliminary phylogeny of the genera Flavopunctelia and Punctelia is presented. Genus and species delimitations have been investigated using ITS rDNA-sequencing of populations from different continents. Current genus delimitations of Flavopunctelia, Punctelia and Parmelia are confirmed and the species status of recently resurrected Punctelia ulophylla is confirmed. The status of three cryptic spe

Sub-monolayers of gold have been grown at room temperature on the hexagonal boron nitride (h-BN) nanomesh formed on Rh(111), and studied systematically with core level and angle-resolved valence band photoelectron spectroscopy. The results are compared with those for the Au/Rh(111) and Au/h-BN/Pt(111) interfaces. It has been found that on clean Rh(111) substrate gold starts to grow two-dimensional

The mechanism for the acid-mediated substitution of a phenolic hydroxyl group with a sulfur nucleophile has been investigated by a combination of experimental and theoretical methods. We conclude that the mechanism is distinctively different in nonpolar solvents (i.e., toluene) compared with polar solvents. The cationic mechanism, proposed for the reaction in polar solvents, is not feasible and th

Partial preferences may occur due to differences in profitability and encounter probability between food types within a patch. In the expanding specialist diet strategy, a forager goes from being partially selective on the preferred, most profitable food, to being opportunistic, after the preferred food has been depleted to a certain critical level. We studied the diet selection strategies of bird

This study assessed the ability of the tongue tip to accurately select intra-oral sensors embedded in a upper palatal interface of 19 able-bodied volunteers. Tongue selectivity performance measures were determined for three different tongue-computer interface layouts. Assessment of intra-oral target selection speed and accuracy revealed that performance was dependent on the location and distance b

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and the total number of AF patients is constantly increasing. The mechanisms leading to and sustaining AF are not completely understood yet. Heterogeneities in atrial electrophysiology seem to play an important role in this context. Although some heterogeneities have been used in in-silico human atrial modeling studies, they have not

Nutrient reduction and the improvement of bottom water oxygen concentrations are thought to be key factors in the recovery of eutrophic aquatic ecosystems. The effects of re oxygenation and bioturbation of natural hypoxic sediments in the Baltic Sea were studied using a mesocosm experiment. Anoxic sediment box cores were collected from 100 m depth in Kanholmsfj rden (Stockholm Archipelago) and mai

Background: The proven benefit of integrating cervical cancer screening programme into HIV care has led to its adoption as a standard of care. However this is not operational in most HIV clinics in Nigeria. Of the various reasons given for non-implementation, none is backed by scientific evidence. This study was conducted to assess the willingness and acceptability of cervical cancer screening amo

Popular Abstract in Swedish Personlighetspsykologer har i mer än ett århundrade försökt att identifiera och beskriva observerbara skillnader mellan individer. Bland dessa indiduella skillnader har intelligens och personlighet fått stor uppmärksamhet inom skolvärlden, liksom elevers förhållningssätt till sitt lärande. Kunskapen om vilka faktorer som påverkar studieresultat har viktiga praktiska konThe aim of the present doctoral thesis was to examine to what extent personality traits and approaches to learning contribute to academic performance in upper secondary school (high school), after controlling for the well-known fact that general intelligence accounts for a large part of the variance. The general proposition of the thesis is that personality traits are stable dispositons and theref

Hornets, the largest social wasps, have a reputation of being facultatively nocturnal. Here we confirm flight activity of hornet workers in dim twilight. We studied the eyes and ocelli of European hornets (Vespa crabro) and common wasps (Vespula vulgaris) with the goal to find the optical and anatomical adaptations that enable them to fly in dim light. Adaptations described for obligately nocturna

Double-stranded DNA in many bacterial viruses (phage) is strongly confined, which results in internal genome pressures of tens of atmospheres. This pressure is strongly dependent on local ion concentration and distribution within the viral capsid. Here, we have used electron energy loss spectroscopy (EELS), energy-filtered TEM (EFTEM) and X-ray energy dispersive spectroscopy to provide such chemic

This paper presents DC and RF characterization as well as modeling of vertical InAs nanowire MOSFETs with LG = 200 nm and Al2O3/HfO2 high-κ dielectric. Measurements at VDS = 0.5 V show that high transconductance (gm = 1.37 mS/μm), high drive current (IDS = 1.34 mA/μm), and low on-resistance (RON = 287 Ωμm) can be realized using vertical InAs nanowires on Si substrates. By measuring the 1/f-noise,

The technique of longitudinal ("xyz") polarization analysis has been used successfully for many years to study disordered magnetic materials in thermal and cold neutron diffraction experiments. The technique allows the simultaneous and unambiguous separation of the nuclear, magnetic, and nuclear spin-incoherent contributions to the scattering. The technical advances seen in recent years, such as t

The production of K*(892)(0) and phi(1020) in pp collisions at root s = 7 TeV was measured by the ALICE experiment at the LHC. The yields and the transverse momentum spectra d(2)N/dydp(T) at midrapidity vertical bar y vertical bar < 0.5 in the range 0 < p(T) < 6 GeV/c for K*(892)(0) and 0.4 < p(T) < 6 GeV/c for phi(1020) are reported and compared to model predictions. Using the yield of pions, kao

The surface structure of Pd(100) during CO oxidation was measured using a combination of a flow reactor and in situ surface X-ray diffraction coupled to a large-area 2-dimensional detector. The surface structure was measured for P-O2/P-CO ratios between 0.6 and 10 at a fixed total gas pressure of 200 mbar and a fixed CO pressure of 10 +/- 1 mbar. In conjunction with the surface structure the react

Chondrules are millimeter-sized spherules that dominate primitive meteorites (chondrites) originating from the asteroid belt. The incorporation of chondrules into asteroidal bodies must be an important step in planet formation, but the mechanism is not understood. We show that the main growth of asteroids can result from gas drag-assisted accretion of chondrules. The largest planetesimals of a pop

This guideline for the investigation and initial treatment of atypical hemolytic uremic syndrome (HUS) is intended to offer an approach based on opinion, as evidence is lacking. It builds on the current ability to identify the etiology of specific diagnostic sub-groups of HUS. HUS in children is mostly due to infection, enterohemorrhagic Escherichia coli (EHEC), Shigella dysenteriae type 1 in some