Search results

Filter

Filetype

Your search for "*" yielded 532186 hits

Early stage of ripple formation on Ge(001) surfaces under near-normal ion beam sputtering

We present a study of the early stage of ripple formation on Ge(001) surfaces irradiated by a 1 keV Xe+ ion beam at room temperature and near-normal incidence. A combination of a grazing incidence x-ray scattering technique and atomic force microscopy allowed us to observe a variation of the symmetry of the surface nanopattern upon increase of the ion fluence. The isotropic dot pattern formed duri

Novel synthesis of the TiO2(B) multilayer templated films

TiO2(B) mesoporous thin films were grown in two steps on the F-doped SnO2 conductive glass substrates. In the first step, a small amount of H3PO4, corresponding to 0.15-0.375 wt % P on TiO2 basis, was introduced into concentrated HCl which was subsequently used for hydrolysis of titanium ethoxide. The hydrolyzed colloidal TiO2 suspension was further mixed with a 1-butanol solution of the amphiphil

X-ray coherent diffraction imaging with an objective lens : Towards three-dimensional mapping of thick polycrystals

We demonstrate an X-ray coherent imaging method that combines high spatial resolution with the ability to map grains within thick polycrystalline specimens. An X-ray objective serves to isolate an embedded grain. Iterative oversampling routines and Fourier synthesis are used to reconstruct the shape and strain field from the far-field intensity pattern. In a demonstration experiment a ∼500-nm Pt g

Synthesis of CdS nanocrystals in polymeric films studied by in-situ GID and GISAXS

In this work, we describe the synthesis of CdS nanocrystals in thin polymeric films by in-situ Grazing Incidence Diffraction (GID) and Grazing Incidence Small Angle Scattering (GISAXS). The 2D GISAXS patterns indicate how the precursor structure is altered as the temperature is varied from 25°C to 300°C. At 150°C, the CdS nanocrystals start to arrange themselves in a hexagonal lattice with a latti

Three-dimensional high-resolution quantitative microscopy of extended crystals

Hard X-ray lens-less microscopy raises hopes for a non-invasive quantitative imaging, capable of achieving the extreme resolving power demands of nanoscience. However, a limit imposed by the partial coherence of third generation synchrotron sources restricts the sample size to the micrometer range. Recently, X-ray ptychography has been demonstrated as a solution for arbitrarily extending the field

Soft x-ray resonant magnetic reflectivity studies for in-and out-of-plane magnetization profile in ultra thin films

The possibility to investigate complex magnetic profiles throughout an ultrathin magnetic film or an interface by soft x-ray resonant magnetic reflectivity is presented. The determination of in- and out-of-plane magnetic profile is shown to be possible with a subnanometer resolution by measuring the reflectivity over a wide angular range. The technique is applied to a granular magnetic multilayer

Investigation of surface and sub-surface damage in high quality synthetic diamonds by X-ray reflectivity and grazing incidence in-plane diffraction

High quality single-crystal synthetic diamond is the most suitable material for selected X-ray optical applications in the latest generation X-ray light sources. Excellent heat handling properties, as well as low absorption, coupled with high perfection in the crystal bulk and very good surface quality, are crucial for such applications. In recent years, some progress has been made in the fields o

The influence of domain permutations of an albumin-binding domain-fused her2-targeting affibody-based drug conjugate on tumor cell proliferation and therapy efficacy

Human epidermal growth factor receptor 2 (HER2) is a clinically validated target for breast cancer therapy. Previously, a drug-fused HER2-targeting affinity protein construct successfully extended the survival of mice bearing HER2-expressing xenografts. The aim of this study was to evaluate the influence of the number and positioning of the protein domains in the drug conjugate. Seven HER2-targeti

Transnationalism, integration och etnisk organisering : En studie av svenska etniska organisationer i ljuset av civilsamhällets omvandling

Artikeln undersöker svenska etniska organisationers verksamheter i syfte att belysa hur detta organisatoriska fält har förändrats under de senaste decennierna. Studien bygger på en totalundersökning av de 52 riksförbund som fått bidrag från Myndigheten för ungdoms- och civilsamhällesfrågor (MUCF). Den visar att det etniska organisationsfältet kännetecknas av både kontinuitet och förändring. Kultur

Application of artificial neural network to forecast engine performance and emissions of a spark ignition engine

Increasing the application of machine learning algorithms in engine development has the potential to reduce the number of experimental runs and the computation cost of computational fluid dynamics simulations. The objective of this study is to assess if such a statistical modelling approach can predict engine efficiency and emissions at any given condition for an already calibrated spark ignition

Nonparametric D-R1-R2 distribution MRI of the living human brain

Diffusion-relaxation correlation NMR can simultaneously characterize both the microstructure and the local chemical composition of complex samples that contain multiple populations of water. Recent developments on tensor-valued diffusion encoding and Monte Carlo inversion algorithms have made it possible to transfer diffusion-relaxation correlation NMR from small-bore scanners to clinical MRI syst

Constructing Transit Corridors : The Politics of Public Transport Policy and Planning in Malmöhus and Skåne 1970-2020

Att planera lokal och regional kollektivtrafik i så kallade ’starka stråk’ – det vill säga att koncentrera infrastruktur och resurser till ett antal färre, men attraktivare stråk i en stad eller en region – är ett standardförfarande i samtida kollektivtrafikplanering. Så har inte alltid varit fallet dock. Denna avhandling visar hur organiseringen av beslutsfattande, planeringspraktiker och den rumPlanning local and regional public transport in so-called ’transit corridors’ – i.e., to concentrate infrastructure and resources to few, but more attractive corridors in a city or a region – is commonplace in contemporary public transport planning. This has not always been the case, however. In this thesis I analyze how transit corridors have come to dominate the policies and planning practices o

Collagen's primary structure determines collagen:HSP47 complex stoichiometry

Collagens play important roles in development and homeostasis in most higher organisms. In order to function, collagens require the specific chaperone HSP47 for proper folding and secretion. HSP47 is known to bind to the collagen triple helix, but the exact positions and numbers of binding sites are not clear. Here, we employed a collagen II peptide library to characterize high-affinity binding si

In situ grazing-incidence small-angle X-ray scattering observation of block-copolymer templated formation of magnetic nanodot arrays and their magnetic properties

The fabrication of bit-patterned media (BPM) is crucial for new types of hard disk drives. The development of methods for the production of BPM is progressing rapidly. Conventional lithography reaches the limit regarding lateral resolution, and new routes are needed. In this study, we mainly focus on the dependence of the size and shape of magnetic nanodots on the Ar+-ion etching duration, using s

Distribution of zinc-blende twins and wurtzite segments in GaAs nanowires probed by X-ray nanodiffraction

We study by X-ray nanodiffraction the statistical distribution of the two possible twinned zinc-blende (ZB) orientations as well as the occurrence of the wurtzite structure within single GaAs nanowires (NWs) grown by molecular beam epitaxy on Si(111). A fast scanning scheme allowed to perform diffraction experiments on 160 individual NWs. We find that although on average the two ZB orientations sh

X-ray nanodiffraction on a single SiGe quantum dot inside a functioning field-effect transistor

For advanced electronic, optoelectronic, or mechanical nanoscale devices a detailed understanding of their structural properties and in particular the strain state within their active region is of utmost importance. We demonstrate that X-ray nanodiffraction represents an excellent tool to investigate the internal structure of such devices in a nondestructive way by using a focused synchotron X-ray

Three-dimensional diffraction mapping by tuning the X-ray energy

Three-dimensional reciprocal-space maps of a single SiGe island around the Si(004) Bragg peak are recorded using an energy-tuning technique with a microfocused X-ray beam with compound refractive lenses as focusing optics. The map is in agreement with simulated data as well as with a map recorded by an ordinary rocking-curve scan. The energy-tuning approach circumvents both the comparatively large

Excessive White Matter Hyperintensity Increases Susceptibility to Poor Functional Outcomes After Acute Ischemic Stroke

Objective: To personalize the prognostication of post-stroke outcome using MRI-detected cerebrovascular pathology, we sought to investigate the association between the excessive white matter hyperintensity (WMH) burden unaccounted for by the traditional stroke risk profile of individual patients and their long-term functional outcomes after a stroke. Methods: We included 890 patients who survived