| 1. |
- Bengtsson, Mats, et al.
(författare)
-
Developing and Implementing a Program Interfacing Project Course in Electrical Engineering
- 2012
-
Konferensbidrag (refereegranskat)abstract
- In this paper, we describe the ideas behind a second-year Design-Build course in Electrical Engineering. Electrical Engineering is a theoretical subject, and in such it is difficult to maintain the theoretical level in project courses introduced too early in the program, especially when core subjects like electromagnetic field theory are involved. This issue is addressed and we also describe our approach for the assessment of the students. We also discuss the different goals that were set up prior to the course from a program perspective; how we reasoned when designing the course, the assessment structure, and the output once the course was implemented
|
|
| 2. |
- Berg, Mikael, Universitetslektor, 1970-, et al.
(författare)
-
Studieresa till Auschwitz : Elevers perspektivtagande i arbetet med förintelsen
- 2018
-
Ingår i: SO-didaktik. - 2002-4525. ; :5, s. 8-19
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Inom historiedidaktiken är begreppet perspektivtagande centralt för förståelsen av ett historiskt fenomen. I den här artikeln tas utgångspunkt i en studieresa till Auschwitz för att undersöka med vilka kunskaper elever försöker skapa förståelse. Resultatet visar att eleverna anänder sig av olika emotioner och ämneskunskaper i sin strävan att tolka sin intryck från studiebesöket.
|
|
| 3. |
- Bergqvist, David, et al.
(författare)
-
Inga dödsfall/slaganfall efter kirurgi vid asymtomatisk karotisstenos : femårsresultat redovisat i riksstäckande register
- 2006
-
Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 103:5, s. 301-302
-
Tidskriftsartikel (refereegranskat)abstract
- In the Swedish vascular registry 7473 carotid endarterectomies are registered, in 10% the indication being a symptomatic stenosis. There are great variations in indication for carotid endarterectomy within Sweden. During the last five years the combined postoperative mortality and/or postoperative permanent stroke has varied between 3% in 1999 and 1.5% in 2003. During the same period not a single patient operated on for a symptomatic carotid stenosis experienced these complications.
|
|
| 4. |
|
|
| 5. |
- Boyle, Henry, et al.
(författare)
-
Insights in α-Al2O3 degradation in multilayer CVD coated carbide tools when turning IN718
- 2023
-
Ingår i: Wear. - : Elsevier BV. - 0043-1648. ; 523
-
Tidskriftsartikel (refereegranskat)abstract
- The degradation behaviour of textured CVD α-alumina has received significant attention within academic literature with regard to steel turning. In contrast, the research performed on Ni-based superalloys is yet to be brought up to the same level of understanding. Hence, the objective of this report will be to offer insights with regard to the degradation mechanisms of the textured alumina layer of CVD Ti(C,N)/α- Al2O3 coated carbides when turning a Ni-based superalloy, and to explore the role of different wear mechanisms that contribute to cutting tool failure. Adhesive wear was observed to be the primary wear mechanism responsible for coating failure, which can result in sudden mechanically driven grain pull-out and delamination events. Grain-pull out was observed across the entire contact zone; delamination was observed to occur most frequently around the trailing edge and depth-of-cut notches, and towards the end of the contact zone as the chip separates from the tool. Evidence of characteristic plastic deformation induced ridges in the alumina coating surface were also revealed within the sliding zone, leading to gradual wear of the alumina layer. These findings demonstrate that there are both similarities and differences in alumina degradation behaviour when compared to previous studies conducted on steel turning.
|
|
| 6. |
- Dalarsson, Mariana, et al.
(författare)
-
Analytical approach to lossy wave propagation through a graded interface containing negative index material
- 2011
-
Ingår i: Int. Conf. Telecommun. Mod. Satell., Cable Broadcast. Serv., TELSIKS - Proc. Pap.. - 9781457720161 ; , s. 39-42
-
Konferensbidrag (refereegranskat)abstract
- The transmission and reflection properties of lossy structures involving left-handed materials with graded permittivity and permeability have been investigated. We present an exact analytical solution to Helmholtz' equation for a lossy case with the graded real parts of permittivity and permeability profile changing according to a hyperbolic tangent function along the direction of propagation. The simple analytical solutions and graphical results for the field intensity along the graded structure are presented. The model straightforwardly allows for arbitrary temporal dispersion.
|
|
| 7. |
- Dalarsson, Mariana, et al.
(författare)
-
Arbitrary Loss Factors In The Wave Propagation Between RHM And LHM Media With Constant Impedance Throughout The Structure
- 2013
-
Ingår i: Progress In Electromagnetics Research. - 1070-4698 .- 1559-8985. ; 137, s. 527-538
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate the wave propagation properties in lossy structures with graded permittivity and permeability involving left-handed metamaterials. An exact analytic solution to Helmholtz' equation for a lossy case with both real and imaginary parts of permittivity and permeability profile, changing according to a hyperbolic tangent function along the direction of propagation, is obtained. It allows for different loss factors in RHM and LHM media. Thereafter, the corresponding numerical solution for the field intensity along the composite structure is obtained by means of a dispersive numerical model of lossy metamaterials that uses a transmission line matrix method based on Z-transforms. We present the expressions and graphical results for the field intensity along the composite structure and compare the analytic and numerical solutions, showing that there is an excellent agreement between them.
|
|
| 8. |
- Dalarsson, Mariana, et al.
(författare)
-
Boundary shape reconstructions in a coaxial waveguide using Bessel functions
- 2016
-
Ingår i: 2016 URSI INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC THEORY (EMTS). - : IEEE. - 9781509025022 ; , s. 826-829
-
Konferensbidrag (refereegranskat)abstract
- This paper investigates boundary shape reconstructions in coaxial waveguides using microwave scattering. Electromagnetic field perturbation theory together with inverse problem theory is used to reconstruct two-dimensional small boundary deformations on the inner boundary of a coaxial waveguide. Due to the first-order perturbation theory employed, the scattering parameters of the waveguide have linear dependencies on the continuous deformation function. Thus, the corresponding inverse problem can be linearized, and direct inversion can be employed to obtain the shape parameters. Tikhonov regularization is used to regularize the resulting ill-conditioned linear system. Finally, reconstruction results are presented for a few examples of two-dimensional localized shape deformations of coaxial waveguide boundaries, being in agreement with the actual shapes.
|
|
| 9. |
- Dalarsson, Mariana, et al.
(författare)
-
Conductor Locations Reconstruction in a Cylindrical Winding Model
- 2013
-
Ingår i: Proceedings of PIERS 2013 in Stockholm, Sweden, August 12-15, 2013. - : ELECTROMAGNETICS ACAD. - 9781934142264 ; , s. 850-857
-
Konferensbidrag (refereegranskat)abstract
- A study of a novel method to detect mechanical deformations of windings in a power transformer, while in operation, is presented. We employ an approximate model of a transformer winding surrounded by the transformer-tank wall and the magnetic core. The transformer winding is viewed as a structure consisting of thin conducting cylindrical rings (winding segments or turns) situated within a coaxial cylindrical waveguide, where the inner conducting cylinder represents the iron core that conducts the magnetic flux and the outer conducting cylinder represents the wall of the transformer tank. The idea is to insert antennas inside the transformer tank above and below the winding to radiate and measure microwave fields that interact with the metallic structure and the insulation. The responses from the radiated waves are assumed to be sensitive to any mechanical deformations that could be caused by electromagnetic forces due to short-circuit currents and possible manufacturing weaknesses. The goal is to determine the radial locations of the individual winding segments or individual turns from measurements of the scattered fields at both ends. The propagation problem is solved by conventional waveguide theory, including mode-matching and cascading techniques. We utilize optimization as a suitable method to solve the inverse problem and obtain an agreement between the reconstructed and true positions of the winding segments.
|
|
| 10. |
- Dalarsson, Mariana, et al.
(författare)
-
Exact Analytical Solution for Fields in a Lossy Cylindrical Structure with Linear Gradient Index Metamaterials
- 2015
-
Ingår i: Progress In Electromagnetics Research. - 1070-4698 .- 1559-8985. ; 151, s. 109-117
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate the electromagnetic wave propagation across a finite inhomogeneous and anisotropic cylindrical metamaterial composite containing both positive and negative effective refractive index parts with linear spatial gradient. Exact analytical solutions for the electric and magnetic field distributions are obtained for a linear variation of effective refractive index across the structure. The exact analytical results for the electric and magnetic fields are compared to the numerical results obtained using the numerical simulation software HFSS. The model allows for general temporal dispersion and uniform losses within the composite.
|
|
