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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
Experimental and theoretical study of nanoparticle deposition using electrostatic interactions
Future electronic devices by aerosol techniques
Single-crystalline tungsten nanoparticles produced by thermal decomposition of tungsten hexacarbonyl
Nanometer-sized particles of W are of interest in semiconductor device research, where such particles may store electrons inside heteroepitaxially defined structures. In this paper, we present results concerning W particles produced by thermal decomposition of tungsten hexacarbonyl. By the described method, it was possible to produce size-selected, single-crystalline W particles in the size range
Aerosol fabrication of nanocrystals of InP
Nanocrystals of indium phosphide, with diameters of around 10nm, have been produced via an aerosol route. The method is based on the formation of monodisperse indium droplets and the subsequent reaction with phosphine at elevated temperature. The size of the final InP nanocrystal is self-limited by the size of the introduced size-selected In droplet. This size can be tuned carefully, thus this met
Single-electron devices via controlled assembly of designed nanoparticles
Single-electron transistors (SET) rely for their functionality on extreme control of lithography and lateral positioning as well as of properties of the building blocks from which the devices are built. By an aerosol-based nanoparticle fabrication we can prepare nanocrystals down to sub-10nm dimensions with metallic or semiconducting character, as well as having a core + shell design for definitio
Size-selected nanocrystals of III-V semiconductor materials by the aerotaxy method
In this paper we present a fabrication route to produce size-selected III-V semiconductor nanocrystals via a simple, reliable, and efficient aerosol route. Since this approach includes the reaction of aerosol particles and a self-organized growth of a new compound, all in the aerosol phase, we call this process aerotaxy. Size-selected nanocrystals of different III-V compounds in a diameter range b