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Potential-dependent surface compression of gold and its link to electrocatalytic reactivity

The surfaces of gold exhibit a rich physical behaviour that is interesting not only from a structural perspective but also for applications in areas such as heterogeneous catalysis and electrocatalysis. In this paper we show that the hexagonal reconstructions of both the Au(111) and the cubic Au(001) surfaces in alkaline electrolyte exhibit a potential-dependent in-plane compression that is remark

Sinus node dysfunction in patients with Fontan circulation : could heart rate variability be a predictor for pacemaker implantation?

Sinus node dysfunction (SND) causes significant morbidity in patients after Fontan surgery. Heart rate variability (HRV) reflects the autonomic regulation of the heart, and changes in HRV have been associated with SND in adults. We aimed to study whether changes in HRV could be detected in 24-h electrocardiographic (ECG) recordings in Fontan patients with SND. We compared HRV results from two pati

Self-organization of porous anodic alumina films studied in situ by grazing-incidence transmission small-angle X-ray scattering

Self-ordered porous anodic alumina (PAA) films are studied extensively due to a large number of possible applications in nanotechnology and low cost of production. Whereas empirical relationships between growth conditions and produced oxides have been established, fundamental aspects regarding pore formation and self-organization are still under debate. We present in situ structural studies of PAA

Influence of Surface Strain on Passive Film Formation of Duplex Stainless Steel and Its Degradation in Corrosive Environment

The effect of surface strain on the passive film evolution of SAF 2507 super duplex stainless steel exposed to ambient air and 0.1 M NaCl solution with varying anodic polarization at room temperature has been investigated using in-situ grazing incidence X-ray diffraction (GIXRD) in combination with electrochemical measurements. Surface strain affected the crystallinity of the passive film as such

Surface X-ray diffraction studies of the electrochemical interface

This thesis describes the application of in-situ surface X-ray diffraction (SXRD) experiments to the study of electrochemical interfaces. Measurements performed at synchrotron radiation facilities are used to provide in-sight into the surface structure of electrodes and the electrochemical double layer. The impact of structural changes on electrochemical reactivity, and likewise the impact of elec

The State of Electrodeposited Sn Nanopillars within Porous Anodic Alumina from In-situ X-ray Observations

Porous anodic alumina (PAA) can be used as a template for controlled electrodeposition and growth of nano-structures, it is also essential for long-lasting decorative coloring of aluminum. We have investigated the deposition of Sn nanopillars into PAA in-situ, with Grazing transmission small angle X-ray scattering, X-ray fluorescence and X-ray absorption near edge structure spectroscopy. An accumu

A novel multiscale neutron diffraction based experimental approach for granular media

The complexity of granular (geo-)materials is associated with the mobility and interaction of their constituent particles. Under the effect of loading, these materials exhibit a highly inhomogeneous behaviour, which might vary significantly as the loading develops (i.e. certain grain assemblies take up the load whilst other, neighbouring assemblies fall into states of lower load). To that end, und

Mining as an underground space producing activity: A financial point of view

Urbanization has resulted in a gigantism of urban complexes and in many environmental and social problems. The situation on the surface and the principles of sustainable development compel urban planners to utilize the urban underground space, which for centuries has been almost exclusively the application field of mining. More often than not spatial planning in urban areas allocates various land-

Effect of A-site substitutions on energy storage properties of BaTiO 3 -BiScO 3 weakly coupled relaxor ferroelectrics

Weakly coupled relaxors based on compositions (1-x) BaTiO 3 -xBiMeO 3 , where Me is a metal ion, have attracted attention as potential candidates for high-temperature high-energy density capacitors. However, the necessary Bi content is typically high with x = 0.3-0.4. In order to reduce problems associated with compatibility for base metal electrodes and due to additional problems due to Bi vol

Burgers rock creep around axisymmetric tunnels

The present paper deals with the time - dependent rock deformation during tunnelling, and more particularly, its association with the related phenomenon of creep in its viscoelastic form, as well as the numerical evaluation of it. Initially, a brief introduction of these two phenomena is provided. Then, the Burgers' idealized model of rheological rock mass behaviour is presented and analysed, alon

Poor Little Rich Kids? The Role of Nature versus Nurture in Wealth and Other Economic Outcomes and Behaviors

Wealth is highly correlated between parents and their children; however, little is known about the extent to which these relationships are genetic or determined by environmental factors. We use administrative data on the net wealth of a large sample of Swedish adoptees merged with similar information for their biological and adoptive parents. Comparing the relationship between the wealth of adopte

Time–dependent rock behaviour in tunnelling

The rock mass viscous behaviour during tunnel construction is discussed. Initially, a brief introduction to the squeezing phenomenon and its association with the related one of creep is provided. Then, existing simplified models of rheological rock mass behaviour are presented and analysed. The range of the viscoelastic rock parameters identified in the literature for weak rocks is also given and

Gold nanoparticles : Production, reshaping, and thermal charging

Gold nanoparticles are of great interest for various nanoelectronic applications, e.g., for making single electron transistors or very fine leads to molecular size entities. For this and other applications, it is important that all particles have controllable size and shape. In this paper, we describe the production of size-selected gold aerosol particles in the 20 nm range made by evaporation in

Feasibility study of nanoparticle synthesis from powders of compounds with incongruent sublimation behavior by the evaporation/condensation method

In this paper we investigate the feasibility of a fabrication route to produce nanocrystals of compound material with incongruent sublimation behavior via the simple evaporation of the powder of the compound. The generation of stoichiometric particles would only be possible if the particle formation occurs at temperatures below the incongruent sublimation point. Our experiments, done on three diff

Gold nanoparticle single electron transistor with carbon nanotube leads

We have used carbon nanotubes to electrically contact a 7 nm gold particle by scanning-probe manipulation. The result was a single-electron transistor showing a periodic modulation of the current as a function of gate voltage for temperatures up to ∼200 K, with the particle responsible for the main features of the electron transport. This interpretation could be verified when the particle was remo

Size-, shape-, and position-controlled GaAs nano-whiskers

We have developed a technique for the synthesis of size-selected, GaAs, epitaxial nano-whiskers, grown on a crystalline substrate. As catalysts, we used size-selected gold aerosol particles, which enabled us to fully vary the surface coverage independently of the whisker diameter. The whiskers were rod shaped, with a uniform diameter between 10 and 50 nm, correlated to the size of the catalytic se

Positioning of nanometer-sized particles on flat surfaces by direct deposition from the gas phase

Arrangements of nanometer-sized particles were obtained on plane oxidized silicon substrates by direct deposition from the gas phase. The particles were attracted onto charge patterns created by contact charging. Monodisperse, singly charged indium aerosol particles with a diameter of 30 nm were used as a test case to illustrate this process. Due to the surface treatment, the deposition is highly