427 research outputs found
Generating Procedural Controls to Facilitate Trade: The Role of Control in the Absence of Trust
Over the years, Trust has been recognized in the Bled community as a key enabling factor to stimulate Electronic Commerce. Authors have discussed formal aspects of trust, the role trust plays in the adoption of both B2B and B2C Electronic Commerce, as well as mechanisms to build trust and/or overcome the lack of it. This article first provides a brief overview of the Trust-related articles in the Bled eConference. It then focuses on one specific aspect of the facilitation of trade in absence of trust: the development of procedural controls that enable Electronic Commerce at arms’ length, summarizing the contributions of the authors on this theme at the Bled Conference since the early 1990s. The paper concludes with the authors’ current view on developing procedural controls, focusing on the design process itself, which is often a rather lengthy process consisting of trial-and -error. Here a more analytical approach is proposed to the identification of control requirements for inter-organizational procedures. The approach involves abstracting the process to identify its basic deontic elements. A model checking approach is then applied to identify needed controls
Reactivity of dolomitizing fluids and Mg source evaluation of fault-controlled dolomitization at the Benicàssim outcrop analogue (Maestrat Basin, E Spain)
Peer reviewedPostprin
The Jabal Akhdar Dome in the Oman Mountains : evolution of a dynamic fracture system
Acknowledgments: This study was carried out within the framework of DGMK (German Society for Petroleum and Coal Science and Technology) research project 718 “Mineral Vein Dynamics Modelling,” which is funded by the companies ExxonMobil Production Deutschland GmbH, GDF SUEZ E&P Deutschland GmbH, RWE Dea AG and Wintershall Holding GmbH, within the basic research program of the WEG Wirtschaftsverband Erdo¨l- und Erdgasgewinnung e.V. We thank the companies for their financial support and their permission to publish these results. The German University of Technology in Oman (GU-Tech) is acknowledged for its logistic support. We gratefully acknowledge the reviewers Andrea Billi and Jean-Paul Breton, whose constructive reviews greatly improved the manuscriptPeer reviewedPreprin
Het Nieuwe Werken: een analyse van de verschillen in de implementatie binnen publieke en private organisaties
Subgrain rotation recrystallization during shearing: insights from full-field numerical simulations of halite polycrystals
We present, for the first time, results of full-field numerical simulations of subgrain rotation recrystallization of halite polycrystals during simple shear deformation. The series of simulations show how microstructures are controlled by the competition between (i) grain size reduction by creep by dislocation glide and (ii) intracrystalline recovery encompassing subgrain coarsening by coalescence through rotation and alignment of the lattices of neighboring subgrains. A strong grain size reduction develops in models without intracrystalline recovery, as a result of the formation of high-angle grain boundaries when local misorientations exceed 15°. The activation of subgrain coarsening associated with recovery decreases the stored strain energy and results in grains with low intracrystalline heterogeneities. However, this type of recrystallization does not significantly modify crystal preferred orientations. Lattice orientation and grain boundary maps reveal that this full-field modeling approach is able to successfully reproduce the evolution of dry halite microstructures from laboratory deformation experiments, thus opening new opportunities in this field of research. We demonstrate how the mean subgrain boundary misorientations can be used to estimate the strain accommodated by dislocation glide using a universal scaling exponent of about 2/3, as predicted by theoretical models. In addition, this strain gauge can be potentially applied to estimate the intensity of intracrystalline recovery, associated with temperature, using quantitative crystallographic analyses in areas with strain gradients
The ephemeral development of C′ shear bands: A numerical modelling approach
C′ shear bands are ubiquitous structures in shear zones but their development is poorly understood. Previous research has determined they mostly occur in rocks with a high mechanical strength contrast. Using numerical models of viscoplastic deformation, we studied the effect of the proportion of weak phase and the phase strength contrast on C′ shear band development during simple shearing to a finite strain of 18. We found that C′ shear bands form in models with ≥5% weak phase when there is a moderate or high phase strength contrast, and they occur in all models with weak phase proportions ≥15%. Contrary to previous research, we find that C′ shear bands form when layers of weak phase parallel to the shear zone boundary rotate forwards. This occurs due to mechanical instabilities that are a result of heterogeneous distributions of stress and strain rate. C′ shear bands form on planes of low strain rate and stress, and not in sites of maximum strain rate as has previously been suggested. C′ shear bands are ephemeral and they either rotate backwards to the C plane once they are inactive or rotate into the field of shortening and thicken to form X- and triangle-shaped structures
A New Stiffness Parameter in Air Puff Induced Corneal Deformation Analysis
OCULUS Optikgerate GmbHOhio State Univ, Ophthalmol & Visual Sci & Biomed Engn, Columbus, OH 43210 USAOhio State Univ, Mech & Aerosp Engn, Columbus, OH 43210 USAUniv Liverpool, Sch Engn, Liverpool, Merseyside, EnglandUniv Insubria, Div Ophthalmol, Varese, ItalyHumanitas Clin & Res Ctr, Ctr Eye, Rozzano, ItalyVincieye Clin, Milan, ItalyRio de Janeiro Corneal Tomog & Biomech Study Grp, Rio De Janeiro, BrazilUniv Fed Sao Paulo, Ophthalmol, Rio De Janeiro, BrazilUniv Fed Sao Paulo, Ophthalmol, Rio De Janeiro, BrazilWeb of Scienc
The Relevance of Grain Dissection for Grain Size Reduction in Polar Ice: Insights from Numerical Models and Ice Core Microstructure Analysis
The flow of ice depends on the properties of the aggregate of individual ice crystals, such as grain size or lattice orientation distributions. Therefore, an understanding of the processes controlling ice micro-dynamics is needed to ultimately develop a physically based macroscopic ice flow law. We investigated the relevance of the process of grain dissection as a grain-size-modifying process in natural ice. For that purpose, we performed numerical multi-process microstructure modelling and analysed microstructure and crystallographic orientation maps from natural deep ice-core samples from the North Greenland Eemian Ice Drilling (NEEM) project. Full crystallographic orientations measured by electron backscatter diffraction (EBSD) have been used together with c-axis orientations using an optical technique (Fabric Analyser). Grain dissection is a feature of strain-induced grain boundary migration. During grain dissection, grain boundaries bulge into a neighbouring grain in an area of high dislocation energy and merge with the opposite grain boundary. This splits the high dislocation-energy grain into two parts, effectively decreasing the local grain size. Currently, grain size reduction in ice is thought to be achieved by either the progressive transformation from dislocation walls into new high-angle grain boundaries, called subgrain rotation or polygonisation, or bulging nucleation that is assisted by subgrain rotation. Both our time-resolved numerical modelling and NEEM ice core samples show that grain dissection is a common mechanism during ice deformation and can provide an efficient process to reduce grain sizes and counter-act dynamic grain-growth in addition to polygonisation or bulging nucleation. Thus, our results show that solely strain-induced boundary migration, in absence of subgrain rotation, can reduce grain sizes in polar ice, in particular if strain energy gradients are high. We describe the microstructural characteristics that can be used to identify grain dissection in natural microstructures
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