REALFAG: Science and Mathematics

Research – Department of Teacher Education

REALFAG: Science and Mathematics

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REALFAG (from the Norwegian word realfag, which encompasses science, technology, engineering and mathematics) is a research group focusing on current knowledge and advanced fundamental research in the scientific disciplines classically known as mathematics, physics, chemistry, biology and geology. These disciplines are in constant development, and they are the backbone of today’s and tomorrow’s STEM education at all school levels.

Are you a graduate student in science education? We have master’s projects available!

Some of the research lines in the group are:

  • Nanothermodynamics. Contact: Rodrigo de Miguel.
  • Thermostatistics of strongly coupled systems. Contact: Rodrigo de Miguel.
  • Electrophysiological properties of neurons of the hippocampus and the entorhinal cortex in brains affected by Alzheimer’s disease. Contact: Pål Kvello.
  • Sensation of CO2 and processing of CO2 - information in the insect nervous system. Contact: Pål Kvello.
  • Quantitative analysis of the collagen structure in cartilage by SHG and P-SHG imaging. Contact: Elisabeth Romijn.
  • Man and nature. Vegetational changes following trampling, burning or scything in protected nature. Contact: Trond Arnesen.
  • Compressed sensing and Bayesian theory. Contact: Solomon Tesfamicael.

Seminars

2020

2019

  • Tuesday, May 14th, 2019. Pål Kvello: «Research on the nervous system of mammals and insects.»
  • Tuesday, June 11th. Elizabeth I. Romijn: «Spectroscopic methods to analyze the collagen structure in cartilage.»
  • Tuesday, December 3rd, 2019. Rodrigo de Miguel: «Strong coupling and negative themophoresis.»

Seminar REALFAG

Speaker: Rodrigo de Miguel

Strong coupling and negative thermophoresis

Abstract:

Thermal gradients may induce mass migration, even in the absence of concentration gradients. Usually, the force induced by the thermal gradient drags the particles in the direction of the heat flow, i.e. from hot to cold. This is known as positive thermophoresis, and it is commonly understood as the result of more momentum transfer from solvent particles on the hot side than on the cold side. However, various particles such as colloids, polymers, charged nanoparticles, magnetic particles, fullerenes, proteins and vesicles have been observed to migrate from cold to hot. These observations suggest that there is more to thermophoresis than plain momentum transfer resulting from collisions between hard particles.

Indeed, negative thermophoresis (drift from cold to hot) is a somewhat counterintuitive phenomenon which has thus far eluded a simple thermostatistical description. A better understanding of the mechanism behind negative thermophoresis can be important for the design and operation of advanced nanosystem properties. For example, in applications such as drug delivery, where local heating is easier than local cooling, it is desirable to guide self-propelled particles towards locally heated targets. The thermophilic motion of nanoparticles may also be used to detect and capture DNA and other biological indicators in serum, allowing for the detection of quantities otherwise unachievable in a thermally homogeneous sample. Thermophilic drift is also believed to be a key mechanism in the self-assembly of the nucleic acids and protocells which lead to the origin of life.

In this talk I present a thermodynamic framework based on the formulation of a Hamiltonian of mean force which has the descriptive ability to capture the interesting and elusive phenomenon of negative thermophoresis in an unusually elegant and straightforward fashion. When a system is strongly coupled to the heat bath, the system’s eigenenergies become effectively temperature dependent. This adjustment of the energy levels allows the system to take heat from the environment and return it as work. This effect can make the temperature dependence of the effective energy profile nonmonotonic. As a result, particles may experience a force in either direction depending on the temperature.

This work has recently been published in Physical Review Letters 123, 200602 (2019).
 

tekst REALFAG

Recent publications

de Miguel, Rodrigo. (2023) Rayleigh-Schrödinger Perturbation Theory and Nonadditive Thermodynamics. Journal of Physical Chemistry B, vol. 127 (5089).

Scriven, David; Johnsen, Anne Berit; Asghari, Parisa; Chou, Keng C; Moore, Edwin D W. (2023) Cardiomyocyte ryanodine receptor clusters expand and coalesce after application of isoproterenol. The Journal of General Physiology.

Nyman, Matias; Tomas, Stølen; Johnsen, Anne Berit; Garten, Karin; Burton, Francis; Smith, Godfrey L. (2023) A comprehensive protocol combining in vivo and ex vivo electrophysiological experiments in an arrhythmogenic animal model. American Journal of Physiology. Heart and Circulatory Physiology.

Nafstad, Ådne M.; Rønning, Bernt; Aase, Kenneth; Ringsby, Thor Harald; Hagen, Ingerid J.; Ranke, Peter S.; Kvalnes, Thomas; Stawski, Clare; Räsänen, Katja; Sæther, Bernt-Erik; Muff, Stefanie; Jensen Henrik. (2023). Spatial variation in the evolutionary potential and constraints of basal metabolic rate and body mass in a wild bird. Journal of Evolutionary Biology.

Le Pepke, Michael; Kvalnes, Thomas; Rønning, Bernt; Jensen, Henrik; Boner, Winnie; Sæther, Bernt-Erik; Monaghan, Pat; Ringsby, Thor Harald. (2022). Artificial size selection experiment reveals telomere length dynamics and fitness consequences in a wild passerine. Molecular Ecology, vol. 31 (23).

de Miguel, Rodrigo; Rubí, J. Miguel. (2021) Gibbs thermodynamics and surface properties at the nanoscale. Journal of Chemical Physics, vol. 55 (221101).

D'Souza, Alicia; […]; Johnsen, Anne Berit; et al. (2021) A circadian clock in the sinus node mediates day-night rhythms in Hcn4 and heart rate. Heart Rhythm.

Ranke, Peter S.; Araya-Ajoy, Yimen G.; Ringsby, Thor Harald; Parn, Henrik; Rønning, Bernt; Jensen, Henrik; Wright, Jonathan; Sæther, Bernt-Erik. (2021). Spatial structure and dispersal dynamics in a house sparrow metapopulation. Journal of Animal Ecology, vol. 90 (12).

Saatoglu, Dilan; Niskanen, Alina K.; Kuismin, Markku; Ranke, Peter S.; Hagen, Ingerid J.; Araya-Ajoy, Yimen G.; Kvalnes, Thomas; Pärn, Henrik; Rønning, Bernt; Ringsby, Thor Harald; Sæther, Bernt—Erik; Husby, Arild; Sillanpää, Mikko J.; Jensen, Henrik. (2021). Dispersal in a house sparrow metapopulation: An integrative case study of genetic assignment calibrated with ecological data and pedigree information. Molecular Ecology, vol. 30 (19).

Araya-Ajoy, Yimen G.; Niskanen, Alina K.; Froy, Hannah; Ranke, Peter Sjolte; Kvalnes, Thomas; Rønning, Bernt; Pepke, Michael Le; Jensen, Henrik; Ringsby, Thor Harald; Sæther, Bernt-Erik; Wright, Jonathan. (2021). Variation in generation time reveals density regulation as an important driver of pace of life in a bird metapopulation. Ecology Letters, vol. 24 (10).

Chu, Xi; KC, Pramod; Ian, Elena; Kvello, Pål; Liu, Yand; Wang, Guirong; Berg, Bente Gunnveig. (2020) Neuronal architecture of the second-order CO2 pathway in the brain of a noctuid moth. Scientific Reports, vol. 10.

KC, Pramod; Chu, Xi; Kvello, Pål; Zhao, Xin-Cheng; Wang, Gui-Rong; Berg, Bente Gunnveig. (2020) Revisiting the Labial Pit Organ Pathway in the Noctuid Moth, Helicoverpa armigera. Frontiers in Physiology, vol. 11 (202).

de Miguel, Rodrigo; Rubí, J. Miguel. (2020) Statistical Mechanics at Strong Coupling: A Bridge between Landsberg’s Energy Levels and Hill’s Nanothermodynamics. Nanomaterials, vol. 10 (2471).

de Miguel, Rodrigo; Rubí, J. Miguel. (2020) Strong Coupling and Nonextensive Thermodynamics. Entropy, vol. 22 (975).

Niskanen, Alina K.; Billing, Anna M.; Holand, Håkon; Hagen, Ingerid J.; Araya-Ajoy, Yimen; Husby, Arild; Rønning, Bernt; Myhre, Ane Marlene; Sjolte Ranke, Peter; Kvalnes, Thomas; Pärn, Henrik; Ringsby, Thor Harald; Lien, Sigbjørn; Sæther, Bernt-Erik; Muff, Stefanie; Jensen, Henrik. (2020) Consistent scaling of inbreeding depression in space and time. Proceedings of the National Academy of Sciences. Biological Sciences, vol. 117 (25).

Heggland, Ingrid; Kvello, Pål; Witter, Menno. (2019) Electrophysiological Characterization of Networks and Single Cells in the Hippocampal Region of a Transgenic Rat Model of Alzheimer’s Disease. eNeuro, vol. 6 (1).

de Miguel, Rodrigo; Rubí, J. Miguel. (2019) Negative thermophoretic force in the strong coupling regime. Physical Review Letters, vol. 123 (200602).

Araya-Ajoy, Yimen; Ranke, Peter Sjolte; Kvalnes, Thomas; Rønning, Bernt; Holand, Håkon; Myhre, Ane Marlene; Pärn, Henrik; Jensen, Henrik; Ringsby, Thor Harald; Sæther, Bernt-Erik; Wright, Jonathan. (2019) Characterizing morphological (co)variation using structural equation models: Body size, allometric relationships and evolvability in a house sparrow metapopulation. Evolution, vol. 73 (3).

person-portlet

Leader of the research group

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Members of the research group

External members of research group

External members of research group

Prof. Miguel Rubi, Dept. of Condensed Matter Physics, University of Barcelona, Spain

Prof. Steven Neshyba, Dept. of Chemistry, University of Puget Sound, USA

Prof. Mark Masthay, Dept. of Chemistry, University of Dayton, USA