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Abstract: This paper presents a platform developed for automated magnetic flux density measurement. The platform was designed to be used to measure the magnetic flux density of the transmitter/receiver coil of an inductive wireless power transfer system. The magnetic flux density of a transmitter was measured using a small, 3-axis search coil. The search coil was positioned in the 3D space above the transmitter coil using a 3D positioning mechanism and used to measure the magnetic flux density at a specific point. The data was then sent to a computer application to visualize the magnetic flux density. The measured magnetic field could be used in combination with electromagnetic field solvers to design and optimize transmitter coils for inductive wireless power transfer systems.
Keywords: magnetic field, magnetic flux density, IPT, transmitter coil design, EM solver
Published in DKUM: 01.04.2025; Views: 0; Downloads: 1
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Abstract: In a typical pressurized water reactor, neutron detectors located outside the reactor core monitor reactor power. In addition, they are also used to measure the reactivity of the control rods. A novel approach to calculate the ex-core neutron detector response in a typical pressurized water reactor using the Monte Carlo technique is presented. A detailed ex-core model of the Krško nuclear power plant was developed using the Monte Carlo neutron transport code MCNP. Due to the location of the ex-core neutron detectors, the hybrid code ADVANTG is used to generate variance reduction parameters to accelerte the convergence of the results outside the reactor core. To use ADVANTG, the fixed neutron source had to be reconstructed from the criticality core calculation. This paper presents the sensitivity analysis of the response of the ex-core detectors to the neutron data libraries used, the description of the fixed neutron source and the ADVANTG parameters. It was found that a pin-wise description of the neutron source for at least two rows of fuel assemblies at the core periphery is necessary for accurate results. Our results show the importance of a correct description of the prompt neutron spectra in the high energy region and the impact this has on the response of the ex-core detectors. The method in which the prompt neutron fission spectra for important fission nuclides are weighted by the calculated reaction rates has been shown to be the best approximation, with deviations from the reference calculation within statistical uncertainty. The effect of nuclear data libraries on the response of the ex-core detector was investigated, and the difference between the ENDF/B-VII.0 and the ENDF/B-VIII.0 nuclear data libraries was ∼11%. When the deficient evaluation of the 56Fe isotope included in the ENDF/B-VIII.0 nuclear data library was replaced by the improved evaluation from the IAEA INDEN project, the differences decreased to ∼3.7%. In addition, neutron flux redistributions due to control rod movement were investigated and flux redistribution factors were updated using Monte Carlo particle transport methods. The reaction rate redistribution factors obtained with methods presented in this paper are within 1% agreement with the currently used factors.
Keywords: MCNP, ADVANTG, pressurized water reactor, Monte Carlo neutron transport, control rod, neutron flux redistribution factor, rod insertion, krško nuclear power plant
Published in DKUM: 29.11.2024; Views: 0; Downloads: 7
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Abstract: Low-cost, readily available, or even disposable membranes in water purification or downstream biopharma processes are becoming attractive alternatives to expensive polymeric columns or filters. In this article, the potential of microfiltration membranes prepared from differently orientated viscose fibre slivers, infused with ultrafine quaternised (qCNF) and amino-hydrophobised (aCNF) cellulose nanofibrils, were investigated for capturing and deactivating the bacteria from water during vacuum filtration. The morphology and capturing mechanism of the single- and multi-layer structured membranes were evaluated using microscopic imaging and colloidal particles. They were assessed for antibacterial efficacy and the retention of selected bacterial species (Escherichia coli, Staphylococcus aureus, Micrococcus luteus), differing in the cell envelope structure, hydrodynamic biovolume (shape and size) and their clustering. The aCNF increased biocidal efficacy significantly when compared to qCNF-integrated membrane, although the latter retained bacteria equally effectively by a thicker multi-layer structured membrane. The retention of bacterial cells occurred through electrostatic and hydrophobic interactions, as well as via interfibrous pore diffusion, depending on their physicochemical properties. For all bacterial strains, the highest retention (up to 100% or log 6 reduction) at >50 L/h∗bar∗m2 flow rate was achieved with a 4-layer gradient-structured membrane containing different aCNF content, thereby matching the performance of industrial polymeric filters used for removing bacteria.
Keywords: fibrous membrane, cationised cellulose nanofibrils, amino-hydrophobised cellulose nanofibrils, antibacterial activity, multi-layer structure, flux, bacteria retention
Published in DKUM: 28.03.2024; Views: 220; Downloads: 12
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Abstract: Axial flux permanent magnet generators (AFPMG) are used in many high torque applications, including wind generators. There are many design methodologies for AFPMG that are connected to simple design equations used for preliminary design. Analytical methods offer a fast preview of torque production of the designed machine with a certain degree of accuracy. The finite element method (FEM) is a more accurate numerical method than other methods and requires a great deal of time for simulations in the design procedure. This article presents a method for the design and analysis of an axial flux permanent magnet generator by using approximation polynomials.
Keywords: Axial flux permanent magnet generator, approximation method, magnetic flux, magnetic flux density
Published in DKUM: 15.11.2023; Views: 469; Downloads: 83
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Abstract: This paper presents a study of the electromagnetic and thermal field of a new construction of a hybrid electromagnetic system with magnetic flux modulation. The numerical studies were realised using the finite element method. The coupled problem electromagnetic field-electric circuit-thermal field was solved. A computer model of the hybrid electromagnetic system was developed for the purpose of the study using the software programme COMSOL. Results for the distribution of the electromagnetic and thermal field in the hybrid electromagnetic system with magnetic modulation were obtained at different supply voltages.
Keywords: Coupled problems, finite element analysis, hybrid electromagnetic system, magnetic flux modulation, permanent magnets
Published in DKUM: 13.11.2023; Views: 265; Downloads: 4
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