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Events - Page 10

Time and place: , room 720 and Zoom - Niels Henrik Abels hus

Doctoral candidate Floris Eelke Elzinga at the Department of Mathematics will be defending the thesis Free Probabilistic and Poisson–Lie Geometric Methods for Quantum Groups for the degree of Philosophiae Doctor.

Time and place: , Niels Henrik Abels hus, 9th floor

The simulation of multi-phase fluids has attained growing interest in the last decades. While for single-phase flow with the Navier-Stokes system the basic model is well understood, for multi-phase systems additional challenges by the necessity to track the transition zones or interfaces between different fluid components arise. 
We propose to use a phase field as a smooth indicator function to describe this situation. Using phase-field models, one introduces a small layer of mixed fluids as a so-called diffuse interface. One benefit of phase-field models is, that they can naturally deal with topology changes and can easily be extended to cope with contact line dynamics.
This model allows for discussing the optimal control problem for two-phase flow. We introduce a thermodynamically consistent phase-field model for two-phase flow including a model for contact line dynamics and introduce an energy stable numerical scheme. 
This scheme allows us to investigate the time-discrete (open loop) optimal control problem, where we investigate different control actions to steer a given distribution of phases towards the desired distribution. We derive the existence of solutions to the optimal control problem and provide first-order optimality conditions.

Hybrid format via Zoom possible on demand (contact timokoch at uio.no)

Time and place: , NHA108

C*-algebra seminar by Marcelo Laca (University of Victoria)

Time and place: , Sophus Lie Conference Center, Nordfjordeid, Norway.

Nordfjordeid Summer school 2022

Time and place: , Niels Henrik Abels hus, 9th floor

Migration of particles and deformation and coalescence of droplets can be highly affected by the non-Newtonian properties of the carrier fluid. 
In this talk, we focus on the effects of viscoelasticity and yield stress (plasticity) on particle and droplet dynamics. Results are presented from numerical simulations of Navier-Stokes equations coupled with viscoelastic and elastoviscoplastic constitutive models. We will investigate how to yield stress and elasticity affect the final position of a particle in channel flows, and how complex fluid droplets deform, merge and jump on a superhydrophobic surface.

Hybrid format via Zoom possible on demand (contact timokoch at uio.no)

Time and place: , NHA 1020 and Online
Time and place: , NHA107

C*-algebra seminar talk by John Quigg (Arizona State University)

Time and place: , NHA 1020 and Online
Time and place: , Helga Engs hus, Auditorium 3

We invite you (once again) to a two-day seminar celebrating Professor Ørnulf Borgans many and substantial contributions to statistics in general and life event history analysis in particular.  

Time and place: , Niels Henrik Abels hus, 9th floor

Brain source analysis is an important tool in brain research. It is used for example during operation planning for epilepsy patients. Given EEG (electroencephalography) and MEG (magnetoencephalography) measurements the goal is to reconstruct the brain activity, i.e. the electric potential in the brain. This poses an inverse problem. It was observed in experiments, that the accuracy of the inverse problem strongly depends on the quality of the forward simulation, in particular the head model. We discuss how modern numerical methods like discontinuous Galerkin (dG) methods and cut-cell techniques can increase the robustness of the forward problem and simplify the overall workflow. Hardware-oriented design of numerical methods allows for improved speed of the inverse simulation by making use of modern hardware resources. In order to compute the forward problem efficiently, we propose an algebraic multigrid solver for cut-cell dG methods. We introduce the challenges of EEG/MEG inverse modeling and discuss how different parts of the problem can be improved using modern numerical methods.

Hybrid format via Zoom possible on demand (contact timokoch at uio.no)

The talk will start at ca. 13:00 right after the talk by Andrea Bressan.

Time and place: , Niels Henrik Abels hus, 9th floor

Abstract: Many constructions have been proposed to attain adaptivity within the IGA framework (HB-, T-, LR-splines among others).
The idea of all approaches is to break the tensor product structure of the space in order to allow a spatially varying resolution.
Here we present an approach for adaptivity in IGA aimed at solving PDEs with preconditioned Krylov methods. 
All the main ingredients of this work are already known, but their combination looks promising for the 
development of isogeometric solvers with a good balance of flexibility and computational efficiency.

Hybrid format via Zoom possible on demand (contact timokoch at uio.no)

Time and place: , room 720 and Zoom - Niels Henrik Abels hus

Doctoral candidate Andreas Nakkerud at the Department of Mathematics will be defending the thesis Integer Programming Approaches for Real-Time Traffic Management for the degree of Philosophiae Doctor.

Time and place: , NHA108

C*-algebra seminar talk by Guillaume Aubrun (Université Claude Bernard Lyon 1)

Time and place: , Erling Svedrups plass, ZOOM
Time and place: , NHA108

C*-algebra seminar talk by Alistair Miller (Queen Mary University of London)

Time and place: , Niels Henrik Abels hus, 9th floor

Abstract: Dynamic Contact Lines are moving lines at which two fluids (eg air and water) and a solid meet. They offer longstanding paradoxes in the theory of continuum mechanics. I describe some aspects of their computation: a curtain-coating numerical experiment, a withdrawing plate, and a droplet between parallel plates.  All computations are done using Volume-Of-Fluid methods on octree grids, and comparisons with phase field and molecular dynamics approaches performed in collaboration with KTH, Stockholm.

Hybrid format via Zoom possible on demand (contact timokoch at uio.no)

Time and place: , NHA 720 and Online
Time and place: , Room 819, Niels Henrik Abel's house

The Section 4 seminar for the Spring of 2022 will be held on Tuesdays from 10:15–12:00 (see the schedule)

Time and place: , University of Oslo

Update (13/01/2023): We are organising a similar workshop from May 3 to May 5, 2023. You can find more information here: click here

You are cordially welcome to participate in this three-day conference on climate, weather and carbon risk in energy and finance. The conference will gather academics and practitioners, discussing the latest advances on the stochastics of risk measuring, modeling and managing, with a focus on energy systems, markets and finance (ESG).

Key topics involve modelling uncertainty in weather and climate, optimisation problems related to energy systems to control emissions, as well as measuring risk factors related to climate change. 

There will be several invited talks by leading researchers as well as selected contributed talks by participants.

 

Time and place: , Erling Sverdrups plass, Niels Henrik Abels hus, 8th floor
Time and place: , NHA108

C*-algebra seminar talk by Judy Packer (University of Colorado Boulder)

Time and place: , NHA108

C*-algebra seminar talk by Roberto Conti (Sapienza University of Rome)

Time and place: , room 720 and Zoom - Niels Henrik Abels hus

Doctoral candidate Markus Musch at the Department of Mathematics will be defending the thesis Analysis and Numerical Treatment of Nonlinear Hyperbolic Conservation Laws on Graphs for the degree of Philosophiae Doctor.

Time and place: , NHA 819

C*-algebra seminar / Gemini Center seminar talk by Paula Belzig (University of Copenhagen)

Time and place: , Niels Henrik Abels hus, 9th floor

Abstract: I present the electrophoretic transport phenomenon of spherical soft particles. Electrophoresis is one of the important electrokinetic techniques, which is often used to characterize, and separation of colloids.  It is commonly used as a separation technique and often used in the separation of DNA, protein molecules, serum to identify paraproteins, etc. Electrophoretic transport phenomenon is also used to understand the electric properties of several bioparticles including virus, bacteria, humic cells and macromolecules and may be used to understand the transport of cargo vessel in treatments of various diseases, e.g., cancer, inflammation, multiple myeloma, rental pathological disorders and macroglobulinemia, etc. Thus, the proper understanding of the electrophoretic transport of soft particles is important to understand the characteristics features of various bio-colloids and macromolecules, which can be viewed as soft particles. In this talk, I will present some of the existing simplified models for electrophoretic transport of soft particles. In addition, I have further extended it for the real situation, considering the effect of pH-dependent charge densities of the inner core and peripheral soft polymeric layer, effect of hydrodynamic slip length of the hydrophobic core surface, etc. 

Hybrid format via Zoom possible on demand (contact timokoch at uio.no)