Improvements in heat transfer network modelling for oil-cooled power transformer windings

Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.In this paper accurate modelling of heat transfer from power transformer winding conductors to cooling oil is envisaged. To this end the network model of Radakovic & Sorgic [1] is validated against more detailed CFD simulation results. Based on this comparison, three model improvements to the network model are proposed. They concern the governing heat transfer correlation, the introduction of thermal boundary layer tracking and an improved description for the thermal resistance in the solid. The improved network model results in more accurate results.The authors acknowledge support from the IWT, in the context of a Baekeland Mandate.am201

Differences in anti-malarial activity of 4-aminoalcohol quinoline enantiomers and investigation of the presumed underlying mechanism of action

International audienc

Revisiting the Immune Trypanolysis Test to Optimise Epidemiological Surveillance and Control of Sleeping Sickness in West Africa

Human African trypanosomiasis (HAT) due to Trypanosoma brucei (T.b.) gambiense is usually diagnosed using two sequential steps: first the card agglutination test for trypanosomiasis (CATT) used for serological screening, followed by parasitological methods to confirm the disease. Currently, CATT will continue to be used as a test for mass screening because of its simplicity and high sensitivity; however, its performance as a tool of surveillance in areas where prevalence is low is poor because of its limited specificity. Hence in the context of HAT elimination, there is a crucial need for a better marker of contact with T.b. gambiense in humans. We evaluated here an existing highly specific serological tool, the trypanolysis test (TL). We evaluated TL in active, latent and historical HAT foci in Guinea, Côte d'Ivoire and Burkina Faso. We found that TL was a marker for exposure to T.b. gambiense. We propose that TL should be used as a surveillance tool to monitor HAT elimination

Microbial diversity and community composition of caecal microbiota in commercial and indigenous Indian chickens determined using 16s rDNA amplicon sequencing

Different alpha diversity indices for each sample of university farm data estimated using QIIME for primer pair P2 data. OTUs were clustered at > 97% similarity. (XLSX 12 kb

The EIRENE and B2-EIRENE codes

The EIRENE neutral gas transport Monte Carlo code has been developed initially for TEXTOR since the early 1980s. It is currently applied worldwide in most fusion laboratories for a large variety of different purposes. The main goal of code development was to provide a tool to investigate neutral gas transport in magnetically confined plasmas. But, due to its flexibility, it also can be used to solve more general linear kinetic transport equations by applying a stochastic rather than a numerical or analytical method of solution. Major applications of EIRENE are in connection with plasma fluid codes, in particular with the various versions of the B2 two-dimensional plasma edge fluid code. The combined code package B2-EIRENE was developed, again initially for TEXTOR applications, in the late 1980s. It too has become a standard tool in plasma edge science. It is currently mainly used for divertor configurations, such as by the ITER central team, to assist the design of the ITER divertor. Both the EIRENE and B2-EIRENE concepts are introduced and illustrated with sample applications

B2- B2.5 Code Benchmarking Part II: Incorporating parallel electrical currents

In the present report we continue the detailed B2 - B2.5 code comparison/extension activity started in [1] (Part I: Modeling Equations, Code Dis-integration) for upgrading of B2-EIRENE fusion edge plasma edge code suits from SOLPS4.3 to SOLPS_ITER. We assess the extended options to include parallel electric currents (and the electric potential) in these computational scrape o layer models. Starting from the original implementation [2] we demonstrate its full equivalence with the later introduced formulation in the B2.5 code by rstly re-deriving both sets of additional equations and boundary conditions, and then secondly carrying out a series of benchmark calculations, continuing the earlier set of reference test cases of [1] to non-ambipolar conditions. We show that also with respect to parallel electrical currents both codes an be perfectlymatched. Our tests so far are limited to single ion uid (no plasma impurities) case, sonic (M=1) plasma outow conditions, and to fully orthogonal, and even rectangular, computational grids

Verifikation und Anwendung des B2-EIRENE Codes (SOLPS-ITER) für magnetisierte Plasmen in zylindrischer Anordnung der PSI-2 Anlage

In dieser Arbeit wird ein numerisches Simulationsmodell der linearen Plasmaanlage PSI-2, die im Forschungszentrum Jülich in Betrieb ist, angewendet und um einige wesentliche vorher im Modell nicht vorhandene physikalische Effekte erweitert. Für die Simulationen wird das für das ITER-Divertor-Design aktuell genutzte Codepaket B2-EIRENE (Version SOLPS4.3) verwendet. Im Rahmen der Arbeit gelang es, experimentelle Ergebnisse und numerische Ergebnisse, die mit einem fuehreren Simulationsmodell (B2-EIRENE, ca. 1995) der Anlage gewonnen wurden, zu reproduzieren. Es wird in einer Sensitivitätsstudie der ad hoc eingeführte kinetischen Flux-Limiters für die parallele Wärmeleitung untersucht und gezeigt, dass dieser die Plasmaparameter signifikant beeinflusst. Damit sind also experimentelle Messungen an PSI-2 immer an mindestens 2 axialen Positionen nötig, um das Rechenmodel festzulegen und dann zu validieren...

Analytical expression for transient heat transfer in concrete core activation

© 2014 ASHRAE. Concrete core activation (CCA) is a large thermal mass which is actively used within a bidlding's HVAC system. This implies that the building controller should account for the CCA thermal characteristics. For this purpose, an analytical expression for the heat transfer in CCA is derived in this paper. This expression can be used to analyze temperature distribution, heat transfer rate, and accumulated heat in a CCA-slab, both in space and in time. Moreover, this paper shows that a further simplification leads to an explicit expression for time as a function of the transferred or stored heat. This is essential for building controllers which need information on start-up times or, in smart grid applications, on the potential for thermal energy storage through the use of heat pumps or chillers.status: publishe