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Tidlegare arrangement - Side 43

Tid og stad: –, Zoom

Join us in this Open Science Lunch session to learn about the benefits of using Electronic Lab Notebooks, and get insights from implementation and use at different institutions in Norway!

Tid og stad: , Undervisningrom 720

Tittel: Discrete-time Survival Analysis with Binomial Martingale Increments

Tid og stad: –, Niels Henrik Abels hus, 9th floor, 919
In this talks we explore two types of buckling in thin cylinder-like structures.  
First, we study the effect of inflation on the swelling-induced wrinkling of thin elastic membranes in a set-up that is commonly used to create microchannels in lab-on-chip applications. Using a combination of experiments, mathematical analysis and associated numerical simulations, we demonstrate that the out-of-plane deformation of the inflated membrane and the resulting anisotropic stress lead to two distinct instabilities as the swelling progresses. The membrane first develops small-amplitude wrinkles that retain the cross-channel symmetry. Their wavelength depends on the pressure and is set in a process similar to the axisymmetric buckling of pressurised, uni-axially compressed cylindrical shells. As swelling increases, the membrane undergoes a secondary instability during which the wrinkles coarsen into large-amplitude folds whose morphology can be controlled by the degree of pre-inflation. We elucidate the fundamental mechanisms responsible for this behaviour to explain how inflation can be used as a control mechanism in the manufacture of microchannels.
Next, we study compression of a beverage can, mostly filled with a liquid. When uniaxially compressed empty cylinders buckle, they typically form periodic structures that break both axial and radial symmetry. By contrast, our liquid-filled cylinder buckle axisymmetrically. The resulting ring buckles are localised and appear sequentially, eventually filling the entire can surface. The final periodic pattern has a predictable wavelength that scales with the shell thickness and radius, as observed in the soft microfluidics channels during the initial stages of wrinkling. We characterise the material properties of the cans experimentally in order to model their post-buckling behaviour. The results of our model, which is similar to the 1-D nonlinear Swift-Hohenberg equation, suggest that the sequential appearance of ring buckles occurs via homoclinic snaking. Our system provides a novel experimental demonstration of this mechanism, thereby linking nonlinear dynamics of localised patterns and mechanics of shell buckling. 
Tid og stad: –, Niels Henrik Abels hus, 9th floor, 919
It is widely known that freezing breaks soft, wet materials. However, the mechanism underlying this damage is still not clear. To understand this process, we freeze model, brittle hydrogel samples, while observing the growth of ice-filled cracks that break these apart. We show that damage is not caused by the expansion of water upon freezing, or the growth of ice-filled cavities in the hydrogel. Instead, local ice growth dehydrates the surrounding hydrogel, leading to drying-induced fracture [1]. This dehydration is driven by the process of cryosuction, whereby undercooled ice sucks nearby water towards itself, feeding its growth. Our results highlight the strong analogy between freezing damage and desiccation cracking, which we anticipate being useful for developing an understanding of both topics (Figure 1). Our results should also give useful insights into a wide range of freezing processes, including cryopreservation, food science and frost heave.
Tid og stad: –, Erling Sverdrups plass, Niels Henrik Abels hus, 8th floor

The Tien Mai is currently a postdoc at FHI. He has held postdoc positions in statistics at NTNU (Trondheim) and in biostatistics at UiO (OCBE). His research spans statistics and machine learning, with a particular interest in PAC-Bayesian analysis. He holds a PhD in Statistics from CREST-ENSAE-ParisTech/Paris Saclay and University College Dublin.

Tid og stad: , Kristen Nygaards sal (5370), Ole Johan Dahls hus / Zoom

Doctoral candidate Abu Sadat Mohammad Sayem at the Department of Informatics, Faculty of Mathematics and Natural Sciences, is defending the thesis The Digitalization of Health Information Systems and Its Impact on the Health Manager’s Empowerment in Bangladesh for the degree of Philosophiae Doctor.

Tid og stad: , room 1259 (Abels Utsikt) - Niels Henrik Abels hus

Doctoral candidate Boxue Zheng at the Department of Mathematics will be defending the thesis Soft wetting phenomena:
exploring the effects of substrate geometry and poro-viscoelasticity
for the degree of Philosophiae Doctor.

Welcome to a Panel Conversation in connection with the exhibition "A feeling of Longing That Freezes and Thaws" (March 7–March 23). The conversation will take place between art and science. contributions from the artist Taylor Alaina Liebenstein Smith, Prof. Sebastian Westermann, and PhD fellows Anfisa Pismeniuk and Mats Ippach (CBA).

Tid og stad: –, https://uio.zoom.us/j/63984506165

Sarah is a research director and professor, working at NORCE Energy and the University of Bergen. 

Tid og stad: –, ZEB Aud. 3

by Stephen G. Warren

Department of Atmospheric & Climate Science, and Astrobiology Program

University of Washington, Seattle, USA

Tid og stad: , V205 Oslo and C329 Tromsø via Zoom

Hylleraas seminar, hosted in Tromsø

Tid og stad: –, NHA B1120
Tid og stad: –, Peisestua (room 304), Svein Rosselands Hus

Michael Haahr, Rosseland Centre for Solar Physics, ITA, UiO

Tid og stad: –, B107 of the Niels Henrik Abel Building.

Mauro Di Nasso, University of Pisa, will give a talk in the Logic Seminar

Tid og stad: , room 1259 (Abels Utsikt) - Niels Henrik Abels hus

Doctoral candidate Anna Piterskaya at the Department of Mathematics will be defending the thesis Plasma Instabilities and Turbulence with Magneto-Hydrodynamics and Spectral Numerical Simulations for the degree of Philosophiae Doctor.

Tid og stad: –, Kjemibygningen, VU10

Møt rådgivere på innovasjon fra Veksthuset for verdiskaping. Møt dem på Kjemisk institutt eller avtal et møte for å diskutere innovasjonsideen din.

Tid og stad: –, Klimahuset

The exhibition explores the relationship between climate change and societal change during the Little Ice Age and asks: Can we learn something from a 300-year-old climate crisis?

Tid og stad: –, https://uio.zoom.us/j/63984506165

Charlotte is a professor at the Institute of Light and Matter (ILM).

Tid og stad: –, ZEB Aud. 3

by Jaganmoy Jodder

Centre for Planetary Habitability

This week's seminar will be a journal club given by Morten Hjorth-Jensen and yours truly, discussing the paper which came up last week:

Experimental critical quantum metrology with the Heisenberg scaling

Tid og stad: , V205 Oslo and C329 Tromsø via Zoom

Hylleraas seminar, hosted in Oslo

Tid og stad: –, Auditorium 3

Dear last semester master student KJEMI/MENA/Lektor

Tid og stad: –, Origo

by Prof Sunniva Siem, NNRC director, UiO

Tid og stad: –, CCSE seminar room

Conjecturing and generalizing are two central practices in mathematics, and mathematical thinking and activity often involve examining patterns across cases to articulate conjectures or generalizations.