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Tidligere arrangementer - Side 2

Tid og sted: , 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 sted: , 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 sted: , 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 sted: , HELSAM, Room 218

The African Anthropology seminar series features James Wintrup, senior researcher at the Chr. Michelsens Institute (CMI)

Tid og sted: , 1249 at Eilert Sundts hus

Department seminar. Ole-Andreas Elvik N?ss is an Assistant Professor at the Department of Business and Management Science at the Norwegian School of Economics (NHH). He will present the paper "Never-Realized Capital Gains" (written with Lucy Msall, University of Chicago).

Tid og sted: , Auditorium U40, Domus Theologica

Arkeologisk fredagsseminar med Hege Damlien og Guro Fossum fra Kulturhistorisk museum.

Tid og sted: , Nucleus, Bikuben, Kristine Bonnevies hus

PhD candidate Lasse Kr?ger Eliassen at the Department of Biosciences, Faculty of Mathematics and Natural Sciences, is defending the thesis 'Unraveling the microbial eukaryotic parasites of copepods: from individual fitness costs to seasonal dynamics' for the degree of PhD.

Tid og sted: , NHA B1120
Tid og sted: , Henrik Wergelands hus 421

The talk will focus on the relationship between speech production and perception in early childhood and the role of pacifiers in language development.

Tid og sted: , Peisestua (room 304), Svein Rosselands Hus

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

Tid og sted: , Aud 4, Eilert Sundts Hus, Blindern

I anledning Arnfinn B?-Ryggs nyskrevne Estetisk leksikon p? Pax forlag, Oslo, arrangeres det et ?pent seminar p? Blindern. Seminaret avsluttes med boklansering og forelesning.

Tid og sted: , Room 225, Henrik Wergelands hus, Blindern campus

Gianina Dru?? (OsloMet/UiO) will present her current research on the Peer Gynt production by Markus&Markus.

Tid og sted: , 1249 at Eilert Sundts hus

Department seminar. John Morrow is a Senior Lecturer affiliated to the Centre for Economic Performance and Centre for Economic Policy Research at Queen Mary University of London. He will present the paper "Firms in Product Space: Adoption, Growth and Competition" (written with Luca Macedoni and Vlad Tyazhelnikov).

Tid og sted: , Kristine Bonnevies hus: Hjort 4512

Catfished: Bio-surveying the Akobo River Highlands and Curating the East African Database ‘Fishtopia’

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

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

In this lecture, Prof. Niki Alsford aims to contribute to a continued effort to reframe the narrative of Taiwan perched on the edge of continent, to instead focus on Taiwan on the edge of ocean.

Tid og sted: , GM 652

Bernhard Hollick (IAKH, UiO)

Tid og sted: , University of Oslo, Blindern, Sophus Bugges Hus Seminarrom 4

Tatiana Cojocari will examine the impact of EU’s “engagement without recognition” policy on the region’s foreign policy and its population.

Tid og sted: , 1249 at Eilert Sundts hus

Department seminar. Lucas Conwell is a Lecturer at the Department of Economics at University College London. He will present the paper "Privatized Provision of Public Transit".

Tid og sted: , Kristine Bonnevies hus 3215 ("Greenhouse") NB Merk stedet!

I dette foredraget presenterer Peder Roberts, som er professor i idéhistorie p? IFIKK, perspektiver p? den naturvitenskapelige forskningen i polaromr?dene etter 2. verdenskrig, gjennom begrepet "orderly development" og organisasjonen Arctic Institute of North America (AINA).

Tid og sted: , Peisestua (room 304), Svein Rosselands Hus

Aditi Bhatnagar, Rosseland Centre for Solar Physics, ITA, UiO

Tid og sted: , Rosenkrantz’ gate 22

The Assad-family has ruled over Syria for more than 50 years. In December, it took opposition groups less than two weeks to overthrow the regime.

Tid og sted: , 澳门葡京手机版app下载sparken, seminar room 230

The Department of Media and Communication are happy to welcome Professor Ben Light, University of Salford, UK, for a talk on researching the everyday and the challenges of the digital.

Tid og sted: , Origo

by Prof Sunniva Siem, NNRC director, UiO

Tid og sted: , Eilert Sundts hus, ninth floor, room 929

The Departmental Seminar Series features Associate Professor Filipe Calv?o, from the Graduate Institute of International and Development Studies at the Geneva Graduate Institute.