Tidligere arrangementer - Side 8
Controlling the spontaneous ruptures of nanoscale liquid thin films is crucial to various applications such as solar cell manufacturing. Over the past few decades, theoretical work based on the long-wave theory of thin liquid films has successfully identified a critical film height, below which the surface nanowaves become linearly unstable, leading to spontaneous rupture. This dewetting in the ‘spinodal regime’ has been repeatedly confirmed in experiments using atomic force microscopy on polymer films. However, ruptures are also observed for thicker films (linearly stable) in a different manner. It is believed that the random (Brownian) movement of particles is the cause of dewetting in this ‘thermal regime’ but the theoretical framework predicting the rupture is missing. In this talk, we present a theory to account for the rupture of a two dimensional linearly stable thin film by utilizing fluctuating hydrodynamics and rare events theory. By modelling the film dynamics with the stochastic thin-film equation (STF) and solving it numerically, we observe rupture in the linearly stable thermal regime and record the average waiting time for rupture. We show that the STF can be rearranged into the form of a gradient flow, which allows us to apply Kramer’s law from the rare events theory to obtain a theoretical prediction of the average waiting time. Molecular dynamics (MD) simulations are also performed and we find good agreements between the numerics, the prediction, and the MD.
Farbod Hassani, Cosmology and Extragalactic Astronomy research group, Institute of Theoretical Astrophysics, University of Oslo.
Abstract:
The Section 4 seminar for the Spring 2024 will be held Thursdays 14:15–15:00 in room 1020
How can research shed light on the pandemic of violence against women, and bring it out of the shadows? How can academia contribute to improved sexual rights globally?
Professor emeritus Arnfinn B?-Rygg gjester instituttet v?rt denne m?neden.
Insights from EV Lithium-ion Battery Technological Innovation System in China
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In this lecture, Dr. Sa?a Isteni? Kotar will provide an overview of Taiwan’s foreign relations and the key factors influencing the formulation of Taiwan’s foreign policy.
Tor Ivar ?stmoe (IFIKK)
Etter et initiativ ved Det italienske utenriksdepartementet, i 欧洲杯在线买球_欧洲杯投注网站推荐@ med Det italienske kulturinstitutt i Oslo, viser den italienske seksjonen ved ILOS filmen ?Dante? av Pupi Avati, laget i 2021.
Our project partner Statkraft owns and operates several hydropower plants in Brazil and requires information about the future potential for hydropower production in this region. To provide inflow projections for the next several decades, we use climate model output in combination with a regression model that links meteorological variables such as precipitation and temperature to inflow over various catchments in the region. The relatively short time period for which observation data are available raises concerns about overfitting. We therefore explore an alternative model fitting approach that retains the original, easily interpretable regression model but estimates the regression coefficients within an artificial neural network (ANN) framework which permits spatial and temporal regularization and thus prevents overfitting. We show some examples of the inflow projections obtained with that methodology and discuss some caveats and limitations.
Fem s?kere er blitt invitert til pr?veforelesninger og intervjuer for stillingen som f?rsteamanuensis innen biomedisinsk fysikk.
Archaeological Friday seminar with ?óra Pétursdóttir, Professor in archaeology at UiO, and ?orger?ur ?lafsdóttir, visual artist from Iceland https://thorgerdurolafsdottir.info/ They will reflect on the value of collaborations between archaeology and the arts, from the perspective of their own collaborations.
Protein condensates inside human cells are liquid-like droplets composed of protein and RNA. These condensates interact with the heterogeneous, active and dense environment of the cytoplasm, crossed by various cytoskeletal filaments such as microtubules and actin. Wetting interactions with the cytoskeleton lead to stereotypical positioning of such protein droplets inside the cell. Using statistical physics approaches, we identified complementary functions of filamentous actin and microtubules: protein droplets couple to actin’s native dynamics in the cell through steric interactions leading to directional motion towards the cell center. Microtubules (and their molecular building-blocks), on the other hand, act as Pickering agents and engage in energetically favorable wetting interactions that lead to a robust localization of protein condensates in microtubule-rich regions of the cell. These interactions are non-specific and ultimately arise from different affinities (contact angles) between condensate and filament, suggesting that similar mechanisms may govern localization of other liquid-like phases within the cell.
Bli med n?r Elizaveta Kibisova, Nele P?ldvere, Silje Susanne Alvestad og Asbj?rn F?lstad gjennomg?r falske nyheter p? forskjellige spr?k.
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In this lecture, Dr. Julia Christine Marinaccio will discuss transnational ties between Taiwanese political parties and overseas communities and other constituencies abroad.
C*-algebra seminar by Mathias Palmstr?m (Norwegian University of Science and Technology)
MED ?nsker ? legge tilrette for debatt og f? frem viktige problemstillinger som en del av fakultetets arbeid med likestilling, diskriminering og mangfold. Bli med du ogs?!
Giulia Frigerio (IFIKK)
Speaker: Anne Kveim Lie, institute of Health and Society, UiO
Guri Bordal Steien will present her longitudinal study of refugee learners of Norwegian, organized by the Multilingualism Research Forum
What happens if we paint a steel box and put a water drop on it before it gets dry? The arcane curiosity arises: Will the paint remain the same or get destroyed? The answer is that it depends on the interaction between the surfaces and the length scale involved. My doctoral work was to study the stability of thin liquid films under aqueous drops. Slippery surfaces were used as a model system because they provide a frictionless surface with low contact angle hysteresis (<2°). We found that thin liquid films are stable on hydrophobic surfaces, while on hydrophilic surfaces, they rupture and dewet into droplets. We observed different dewetting patterns depending on the film thickness and slip. However, films on hydrophobic surfaces are stable but can be destabilized using external perturbations like an electric field. Due to the electric field, capillary waves are generated, and their evolution matches very well with a linear stability analysis. The reversible dewetting behavior with the applied field is an interesting observation of our work. With the applied frequency, the wavelength of the capillary waves does not follow the classical linear stability analysis; we modified the stability analysis, which agrees with our experimental findings. Finally, the coalescence of dewetted droplets and anomalous diffusive behavior with the applied external field will be discussed
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I dag kan vi ikke si sikkert hva den engelske svettesyken var, men da den dukket opp for f?rste gang i 1485 var legekunsten sikker i sin sak: Det var snakk om pest. Den oppfatningen skulle endre seg.
Artem Basyrov, Cosmology and Extragalactic Astronomy research group, Institute of Theoretical Astrophysics, University of Oslo.