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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

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

Lunds domkyrka, det universella rummet

An investigation on the different levels of interpretation of medieval architectural iconography. The architecture and sculpture of Lund cathedral is related to function, history, politics and religion.

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La conferencia plantea la necesidad de un tránsito hacia otras formasde aplicar la semiótica en el diseño.La semiótica del diseño con enfoque agentivo ofrece elementos paraconocer en detalle la experiencia humana y las condiciones que determinanla construcción de sentido que emerge cuando un usuario integra artefactosa dicha experiencia para el cumplimiento de sus objetivos.El asumir un enfoque se

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This research aims to encourage interdisciplinary and inter-institutionalcollaborative work through the design and manufacture of an electricvehicle. The goal is to design an experimental vehicle concept in order toimprove sustainable mobility in Bogotá.Industrial Center of Maintenance and Manufacturing CIMM, SENABoyacá, is manufacturing the prototype designed by the team ofresearchers, while priv

Effect of H2/CO ratio and N2/CO2 dilution rate on laminar burning velocity of syngas investigated by direct measurement and simulation

Laminar burning velocities of syngas/air premixed flames, varying with H2/CO ratio (from 5/95 to 75/25) and N2 or CO2 dilution rate (from 0% to 60%), were accurately measured using a Teflon coated Heat Flux burner and OH-PLIF based Bunsen flame method. Experiments were carried out at atmospheric pressure and room temperature, with fuel/air equivalence ratios ranging from fuel-lean to fuel-rich. Co

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Car-sharing systems with electric vehicles are an alternativeto reduce commuting times in big cities and also to mitigateair pollution. Car-sharing exists in 1100 cities around theworld. These systems have had positive effects in the cities,replacing between 9 and 23 private vehicles for each car. Thisdocument proposes a public car-sharing system for Bogotá.The article focuses on the design and ma

Non-uniform nanosecond gate-delay of hybrid pixel detectors

A simple experiment to characterize the gating properties of X-ray area detectors using pulsed X-ray sources is presented. For a number of time-resolved experiments the gating uniformity of area detectors is important. Relative gating delays between individual modules and readout chips of PILATUS2 series area X-ray detectors have been observed. For three modules of a PILATUS300K-W unit the maximum

Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100)

We investigated the intrinsic reactivity of CO on single-layer and multilayer PdO(101) grown on Pd(100) using temperature-programmed reaction spectroscopy (TPRS) and reflection absorption infrared spectroscopy (RAIRS) experiments, as well as density functional theory (DFT) calculations. We find that CO binds more strongly on multilayer than single-layer PdO(101) (∼119 kJ/mol vs 43 kJ/mol), and tha