Time filter

Source Type

Trondheim, Norway

SINTEF , headquartered in Trondheim, Norway, is the largest independent research organisation in Scandinavia. Every year, SINTEF supports research and development at 2,000 or so Norwegian and overseas companies via its research and development activity. The acronym SINTEF means "The Foundation for Scientific and Industrial Research". SINTEF was established at the Norwegian Institute of Technology in Trondheim in 1950 and expanded rapidly in the following years. The largest expansion came in 1993 when the "Centre for Industrial Research" in Oslo merged with SINTEF and created the SINTEF Oslo campus. Wikipedia.

Pradhan S.,Norwegian University of Science and Technology | Pradhan S.,Sintef | Hansen A.,Norwegian University of Science and Technology | Chakrabarti B.K.,Saha Institute of Nuclear Physics
Reviews of Modern Physics | Year: 2010

The fiber bundle model describes a collection of elastic fibers under load. The fibers fail successively and, for each failure, the load distribution among the surviving fibers changes. Even though very simple, this model captures the essentials of failure processes in a large number of materials and settings. A review of the fiber bundle model is presented with different load redistribution mechanisms from the point of view of statistics and statistical physics rather than materials science, with a focus on concepts such as criticality, universality, and fluctuations. The fiber bundle model is discussed as a tool for understanding phenomena such as creep and fatigue and how it is used to describe the behavior of fiber-reinforced composites as well as modeling, e.g., network failure, traffic jams, and earthquake dynamics. © 2010 The American Physical Society. Source

Gustavsen B.,Sintef
IEEE Transactions on Power Delivery | Year: 2010

Power transformers can fail from dielectric stresses caused by electromagnetic transients. In this paper, we focus on a special phenomenon where excessive overvoltages arise due to resonance. This situation can take place when a transformer on the high-voltage side is connected to a cable and the low-voltage side is unloaded. Very high overvoltages can then result on the low-voltage side from transient events that cause a weakly attenuated overvoltage on the cable with a dominant frequency matching a resonance peak in the transformer voltage ratio. Laboratory tests on a 11-kV/230 V distribution transformer show that a step voltage excitation on a 27-m cable produces 24-p.u. overvoltage on the open low-voltage side. The voltage waveforms are accurately reproduced by a black-box model obtained from frequency sweep measurements. Simulations show that overvoltages as high as 43 p.u. could occur with the most unfavorable cable length. It is further shown that the following situations can lead to high overvoltages on an unloaded transformer low-voltage side: 1) ground fault initiation at the far cable end, 2) cable energization from a busbar with several other cables connected, 3) cable energization from another cable with the same length, and 4) capacitor bank energization at the far cable end. © 2010 IEEE. Source

Considering the increasingly complex media landscape and diversity of use, it is important to establish a common ground for identifying and describing the variety of ways in which people use new media technologies. Characterising the nature of media-user behaviour and distinctive user types is challenging and the literature offers little guidance in this regard. Hence, the present research aims to classify diverse user behaviours into meaningful categories of user types, according to the frequency of use, variety of use and content preferences. To reach a common framework, a review of the relevant research was conducted. An overview and meta-analysis of the literature (22 studies) regarding user typology was established and analysed with reference to (1) method, (2) theory, (3) media platform, (4) context and year, and (5) user types. Based on this examination, a unified Media-User Typology (MUT) is suggested. This initial MUT goes beyond the current research literature, by unifying all the existing and various user type models. A common MUT model can help the Human-Computer Interaction community to better understand both the typical users and the diversification of media-usage patterns more qualitatively. Developers of media systems can match the users' preferences more precisely based on an MUT, in addition to identifying the target groups in the developing process. Finally, an MUT will allow a more nuanced approach when investigating the association between media usage and social implications such as the digital divide. © 2010 Elsevier Ltd. All rights reserved. Source

Brandtzaeg P.B.,Sintef
Journal of Computer-Mediated Communication | Year: 2012

The rapid adoption of social networking sites (SNSs) raises important questions about the social implications of such usage. Drawing on unique longitudinal data, surveying a representative sample of Norwegian online users (N=2,000, age 15-75 years) in 3 annual waves (2008, 2009, and 2010), this study found a significantly higher score among SNS users in comparison to nonusers in 3 out of 4 social capital dimensions: face-to-face interactions, number of acquaintances, and bridging capital. However, SNS-users, and in particular males, reported more loneliness than nonusers. Furthermore, cluster analyses identified 5 distinct types of SNS users: Sporadics, Lurkers, Socializers, Debaters, and Advanced. Results indicate that Socializers report higher levels of social capital compared to other user types. © 2012 International Communication Association. Source

Numerical simulations of power-law fluid flow in a rough fracture of regular or irregular topography were carried out using the finite-volume method under the assumptions of the lubrication theory approximation. The model was verified by comparing its results with analytical results available for regular 1D sinusoidal profiles across or along the flow. For a regular profile with sinusoidal variation of the aperture in both directions, the model confirmed that a geometric average can be used as a first approximation, as long as the variation in the profile is not too large. For all fracture topographies studied, reducing the exponent, i.e. making the fluid more shear-thinning, resulted in increasing equivalent hydraulic aperture. The normalized equivalent hydraulic aperture decreased with the normalized standard deviation of the fracture aperture for all fracture topographies studied, except a fracture with a large-scale feature representing a zone of overlap in the middle of the fracture. The validity of the assumptions made in the numerical simulations, in particular the lubrication theory approximation, is discussed and the directions for future work are outlined in conclusion. © 2013 Elsevier Ltd. Source

Discover hidden collaborations