The transfer capabilities of over-head power lines are often limited by the critical power line temperature that depends on the magnitude of the transferred current and the ambient conditions, i.e. ambient temperature, wind, precipitation, etc. To utilize existing power lines more effectively and more safely, concerning the critical power line temperatures, and to enforce safety measures during potentially dangerous events, dynamic assessment of the thermal rating is required. In this paper, a Dynamic Thermal Rating model that covers the most important weather phenomena, with special emphasis on rain, is presented. The model considers dynamic heat generation due to the Joule losses within the conductor and heat exchange with the surrounding in terms of convection, radiation, evaporation, rain impinging and solar heating. The model is validated by comparison of the skin and core temperatures of the power line with measurements under realistic environmental conditions.
COBISS.SI-ID: 30421287
We propose a new data-flow based approach for the identification of backbones in infinite clusters on 2-D percolation site lattices of dimension L x L. First, the infinite cluster is identified, then a multi-step algorithm is applied for the reduction of the infinite cluster to its backbone. Algorithm performances are evaluated theoretically and experimentally. The algorithm is local and can therefore be efficiently implemented on data-flow parallel platforms in O (L) time, if applied on percolation lattices near the critical percolation probability, or in O (L^2) in the worst case. The proposed methodology can resolve the problem of stack over-flow in large systems that can appear with classical graph-based algorithms, and has therefore a potential for higher execution speed-up on parallel architectures.
COBISS.SI-ID: 29117223
The performance of a Differential Evolution for Multi-objective Optimization in a non-linear coupled transport problem, solved by a Meshless Local Strong Form Method (MLSM), is assessed from different points of view. First, the behaviour of the optimization algorithm is tested for different scenarios, ranging from optimization of trivial diffusive transport to more complex non-linear natural convection problems. Second, a hybrid parallel implementation of both the optimization and simulation codes is introduced, to optimize execution time, since such simulation-based optimization might require a vast amount of computational power.
COBISS.SI-ID: 29639719
We investigated the effect of physical inactivity on the composition of intestinal microbiota in healthy men. The environment was strictly laboratory, with balanced liquids and dietary intake, controlled circadian rhythm, microbial ambient burden and 24-hour medical surveillance. We measured several parameters related to the intestinal environment, such as the defecation frequency, intestinal electrical conductivity, sterol and polyphenol content, and the variety, aromaticity and spectral characteristics of the dissolved organic matter. A new PlanHab database was established, which contains all measured variables. The results show that the transition from a healthy physiological state to developed symptoms associated with obesity depends on the duration of inactivity and is associated with changes in the bacterial microbial group.
COBISS.SI-ID: 30421799