Tag Archives: University of Oslo

Fluid mechanics in the kitchen

Caption: Dr. Maciej Lisicki is developing a formula for perfectly creamy ice cream in his laboratory. Credit Photo: Michal Czerepaniak, source: Faculty of Physics, University of Warsaw.

It’s unusual to see a scientist in an orange (maybe it could be called fire engine red?) jumpsuit as it has an altogether different meaning (prison wear) in the US.

Sadly, there isn’t a video of Dr. Maciej Lisicki or other scientists in the kitchen but here’s a description of what they’ve been up to from a June 22, 2023 University of Warsaw (Poland) press release (also on EurekAlert),

Take four brilliant physicists who specialize in fluid mechanics and put them in the kitchen. Give them pots, pans, basic foodstuffs, and a bottle of champagne. Add a COVID-19 pandemic, a pinch of boredom, and a handful of good ideas. Stir, wait, and voilà – you have a “delicious” publication that will teach you how bubbles are created in champagne, how to brew the perfect espresso, and how “kitchen revolutions” can contribute to innovations in many fields, including biomedicine and nanotechnology.

Most of us visit this place every day. But the kitchen is not just for cooking meals. “It can be an excellent place to conduct experiments and even make scientific discoveries,” argues Maciej Lisicki, of the Faculty of Physics of the University of Warsaw, co-author of a publication in the prestigious journal Reviews of Modern Physics. The team of researchers, which in addition to Maciej Lisicki includes Arnold Mathijssen of the University of Pennsylvania, Endre J.L. Mossige of the University of Oslo and Vivek N. Prakash of the University of Miami, not only explores the history of food science, but also shows how phenomena in the kitchen lead to innovations in biomedicine and nanotechnology.

COVID pandemic and bubbles in champagne

Maciej Lisicki and his fellow researchers began working on the article during the COVID-19 pandemic, when many researchers could not work in the lab and began experimenting in their homes. “It started primarily with the intention to make an educational tool, given that kitchens offer a low barrier of entry to doing science — all you need are some pots, pans, and a few ingredients to get a few reactions going—but it quickly grew into a more scientific reflection of the history of food once we realized how interwoven the fields are,” says Arnold Mathijssen.

The team of researchers constructed the results of their work along the lines of a menu. “Tasting” begins with the physics of drinks and cocktails, then moves on to main courses, and finishes with coffee and desserts, whose preparation is also based on the intuitive use of the laws of nature.

As with any good party, everything begins with the opening of a bottle of champagne. After a characteristic “pop”, we observe how a mist forms around the neck of the bottle. – This phenomenon is associated with a rapid change in pressure. Inside the bottle it reaches almost five atmospheres, but when the bottle is opened it drops to one atmosphere.  “The expansion is accompanied by a drop in temperature, which causes the water vapor that accumulates near the mouth of the bottle to freeze, and the carbon dioxide coming out of the bottle to condense”, Maciej Lisicki explains.

In their paper, the researchers also look at bubbles, which give sparkling wines their unique flavor. “Circulating bubbles force the transport of the liquid in the glass, and thus facilitate the release and spread of aromatic notes and flavors”, the researcher adds. From the section of the paper devoted to drinks and cocktails, we will also learn what makes the foam in beer so thick and stable, why aniseed drinks such as rakija and ouzo get cloudy when enough water is added (the phenomenon is even called the “ouzo effect”), and what “tears of wine” are.

When water surfs the pan

Moving on to the main course, the scientists explain the role of heat and its effect on food textures, aromas, and flavors. Among other things, they describe the Leidenfrost effect, in which a drop of liquid placed on a very hot surface forms an insulating layer of vapor, that prevents rapid boiling. “Water drops thrown onto the pan ‘surf’ and even bounce off the surface, instead of evaporating immediately”, Lisicki says. 

Proper temperature is crucial in the preparation of many foods. “It doesn’t take a Ph.D. in physics to fry the perfect steak. Everyone knows that one needs to quickly sear the meat in a sufficiently hot pan. As a result, the proteins on the surface of the steak coagulate and the moisture is kept inside”, the researcher explains. 

A Ph.D. in dishwashing

The text also includes examples of scientific discoveries that researchers have made without leaving their own kitchens. One of them is related to the biography of Agnes Pockels.

“Her story speaks of the inequality in science. She was a woman in Germany in the late 19th century, so she was not allowed to attend university for formal training, making it difficult for her to submit her research to journals,” Mathijssen says.

Running her parents’ household and spending a lot of time in the kitchen, she quickly began experimenting there. “Observing the formation of foam and films on the surface of dirty dishes, she was the first to describe the phenomenon of surface tension and developed an instrument to measure it. Initially, scientific journals were reluctant to publish the results of her experiments due to her lack of formal training and affiliation with university staff. Her first paper was published through Lord Rayleigh in Nature and contributed to the understanding of surface effects in liquids. Agnes Pockels then became well-known and respected, and all her subsequent work was published in high-profile journals. This example shows that it is possible to become a respected scientist without leaving home,” notes Maciej Lisicki.

Salad dressing vs. nanoengineering

Research in fluid mechanics can help improve food processing technologies, as well as find applications in other fields such as nanoengineering and medicine. “In an earlier study (“Rechargeable self-assembled droplet microswimmers driven by surface phase transitions”, published in Nature Physics) conducted by my team, we used a simple emulsion that is the basis of salad dressings – oil with water. We were able to make droplets of such an emulsion, with the addition of a surfactant, form tendrils under temperature and move like bacteria. Such nontoxic, biocompatible microfluidics could be used in the future, for example, to precisely deliver drugs anywhere in our bodies”, Lisicki explains. 

The review also highlights the applicability of these technologies in areas such as food safety and quality control. By deploying devices that can detect food-borne pathogens or toxins using principles of fluid dynamics, the scientific community can contribute significantly to public health.

Another key aspect of their review is the potential impact it could have on policy decisions, particularly those related to environmental sustainability and food safety. The authors highlight the significance of science-based policies, for example – referencing the announced EU ban on PFAS non-stick coatings by 2030. Using the scientific understanding offered by studies like these, policy makers can make informed decisions to foster a more sustainable and safer food future.

“Kitchen flows show us that significant scientific problems are available at our fingertips and do not always require space technology to explore them. On the other hand, more than a few cosmic technologies were born from inspiration by everyday phenomena. The kitchen can therefore entertain us, but also teach us – in this case, physics. This is why it is worth a try to unleash your curiosity and experiment!” Lisicki adds.

This research was supported by the United States Department of Agriculture (USDA-NIFA AFRI 2020-67017-30776 and 2020-67015-32330).

Faculty of Physics of the University of Warsaw
Physics and astronomy at the University of Warsaw appeared in 1816 as part of the then Faculty of Philosophy. In 1825, the Astronomical Observatory was established. Currently, the Faculty of Physics at the University of Warsaw consists of the following institutes: Experimental Physics, Theoretical Physics, Geophysics, the Department of Mathematical Methods and the Astronomical Observatory. The research covers almost all areas of modern physics, on scales from quantum to cosmological. The Faculty’s research and teaching staff consists of over 200 academic teachers, 88 of whom are professors. About 1,100 students and over 170 doctoral students study at the Faculty of Physics at the University of Warsaw.

Perhaps the paper provides more information about the ice cream research depicted in the visual image at the top of this posting. Here’s a link to and a citation for the paper,

Culinary fluid mechanics and other currents in food science by Arnold J. T. M. Mathijssen, Maciej Lisicki, Vivek N. Prakash, and Endre J. L. Mossige. Rev. Mod. Phys. Vol. 95, Iss. 2 — April – June 2023 025004 DOI: https://doi.org/10.1103/RevModPhys.95.025004 Published: 5 June 2023 © 2023 American Physical Society

This paper is behind a paywall.

Graphene goes to the moon

The people behind the European Union’s Graphene Flagship programme (if you need a brief explanation, keep scrolling down to the “What is the Graphene Flagship?” subhead) and the United Arab Emirates have got to be very excited about the announcement made in a November 29, 2022 news item on Nanowerk, Note: Canadians too have reason to be excited as of April 3, 2023 when it was announced that Canadian astronaut Jeremy Hansen was selected to be part of the team on NASA’s [US National Aeronautics and Space Administration] Artemis II to orbit the moon (April 3, 2023 CBC news online article by Nicole Mortillaro) ·

Graphene Flagship Partners University of Cambridge (UK) and Université Libre de Bruxelles (ULB, Belgium) paired up with the Mohammed bin Rashid Space Centre (MBRSC, United Arab Emirates), and the European Space Agency (ESA) to test graphene on the Moon. This joint effort sees the involvement of many international partners, such as Airbus Defense and Space, Khalifa University, Massachusetts Institute of Technology, Technische Universität Dortmund, University of Oslo, and Tohoku University.

The Rashid rover is planned to be launched on 30 November 2022 [Note: the launch appears to have occurred on December 11, 2022; keep scrolling for more about that] from Cape Canaveral in Florida and will land on a geologically rich and, as yet, only remotely explored area on the Moon’s nearside – the side that always faces the Earth. During one lunar day, equivalent to approximately 14 days on Earth, Rashid will move on the lunar surface investigating interesting geological features.

A November 29, 2022 Graphene Flagship press release (also on EurekAlert), which originated the news item, provides more details,

The Rashid rover wheels will be used for repeated exposure of different materials to the lunar surface. As part of this Material Adhesion and abrasion Detection experiment, graphene-based composites on the rover wheels will be used to understand if they can protect spacecraft against the harsh conditions on the Moon, and especially against regolith (also known as ‘lunar dust’).

Regolith is made of extremely sharp, tiny and sticky grains and, since the Apollo missions, it has been one of the biggest challenges lunar missions have had to overcome. Regolith is responsible for mechanical and electrostatic damage to equipment, and is therefore also hazardous for astronauts. It clogs spacesuits’ joints, obscures visors, erodes spacesuits and protective layers, and is a potential health hazard.  

University of Cambridge researchers from the Cambridge Graphene Centre produced graphene/polyether ether ketone (PEEK) composites. The interaction of these composites with the Moon regolith (soil) will be investigated. The samples will be monitored via an optical camera, which will record footage throughout the mission. ULB researchers will gather information during the mission and suggest adjustments to the path and orientation of the rover. Images obtained will be used to study the effects of the Moon environment and the regolith abrasive stresses on the samples.

This moon mission comes soon after the ESA announcement of the 2022 class of astronauts, including the Graphene Flagship’s own Meganne Christian, a researcher at Graphene Flagship Partner the Institute of Microelectronics and Microsystems (IMM) at the National Research Council of Italy.

“Being able to follow the Moon rover’s progress in real time will enable us to track how the lunar environment impacts various types of graphene-polymer composites, thereby allowing us to infer which of them is most resilient under such conditions. This will enhance our understanding of how graphene-based composites could be used in the construction of future lunar surface vessels,” says Sara Almaeeni, MBRSC science team lead, who designed Rashid’s communication system.

“New materials such as graphene have the potential to be game changers in space exploration. In combination with the resources available on the Moon, advanced materials will enable radiation protection, electronics shielding and mechanical resistance to the harshness of the Moon’s environment. The Rashid rover will be the first opportunity to gather data on the behavior of graphene composites within a lunar environment,” says Carlo Iorio, Graphene Flagship Space Champion, from ULB.

Leading up to the Moon mission, a variety of inks containing graphene and related materials, such as conducting graphene, insulating hexagonal boron nitride and graphene oxide, semiconducting molybdenum disulfide, prepared by the University of Cambridge and ULB were also tested on the MAterials Science Experiment Rocket 15 (MASER 15) mission, successfully launched on the 23rd of November 2022 from the Esrange Space Center in Sweden. This experiment, named ARLES-2 (Advanced Research on Liquid Evaporation in Space) and supported by European and UK space agencies (ESA, UKSA) included contributions from Graphene Flagship Partners University of Cambridge (UK), University of Pisa (Italy) and Trinity College Dublin (Ireland), with many international collaborators, including Aix-Marseille University (France), Technische Universität Darmstadt (Germany), York University (Canada), Université de Liège (Belgium), University of Edinburgh and Loughborough.

This experiment will provide new information about the printing of GMR inks in weightless conditions, contributing to the development of new addictive manufacturing procedures in space such as 3d printing. Such procedures are key for space exploration, during which replacement components are often needed, and could be manufactured from functional inks.

“Our experiments on graphene and related materials deposition in microgravity pave the way addictive manufacturing in space. The study of the interaction of Moon regolith with graphene composites will address some key challenges brought about by the harsh lunar environment,” says Yarjan Abdul Samad, from the Universities of Cambridge and Khalifa, who prepared the samples and coordinated the interactions with the United Arab Emirates.    

“The Graphene Flagship is spearheading the investigation of graphene and related materials (GRMs) for space applications. In November 2022, we had the first member of the Graphene Flagship appointed to the ESA astronaut class. We saw the launch of a sounding rocket to test printing of a variety of GRMs in zero gravity conditions, and the launch of a lunar rover that will test the interaction of graphene—based composites with the Moon surface. Composites, coatings and foams based on GRMs have been at the core of the Graphene Flagship investigations since its beginning. It is thus quite telling that, leading up to the Flagship’s 10th anniversary, these innovative materials are now to be tested on the lunar surface. This is timely, given the ongoing effort to bring astronauts back to the Moon, with the aim of building lunar settlements. When combined with polymers, GRMs can tailor the mechanical, thermal, electrical properties of then host matrices. These pioneering experiments could pave the way for widespread adoption of GRM-enhanced materials for space exploration,” says Andrea Ferrari, Science and Technology Officer and Chair of the Management Panel of the Graphene Flagship. 

Caption: The MASER15 launch Credit: John-Charles Dupin

A pioneering graphene work and a first for the Arab World

A December 11, 2022 news item on Alarabiya news (and on CNN) describes the ‘graphene’ launch which was also marked the Arab World’s first mission to the moon,

The United Arab Emirates’ Rashid Rover – the Arab world’s first mission to the Moon – was launched on Sunday [December 11, 2022], the Mohammed bin Rashid Space Center (MBRSC) announced on its official Twitter account.

The launch came after it was previously postponed for “pre-flight checkouts.”

The launch of a SpaceX Falcon 9 rocket carrying the UAE’s Rashid rover successfully took off from Cape Canaveral, Florida.

The Rashid rover – built by Emirati engineers from the UAE’s Mohammed bin Rashid Space Center (MBRSC) – is to be sent to regions of the Moon unexplored by humans.

What is the Graphene Flagship?

In 2013, the Graphene Flagship was chosen as one of two FET (Future and Emerging Technologies) funding projects (the other being the Human Brain Project) each receiving €1 billion to be paid out over 10 years. In effect, it’s a science funding programme specifically focused on research, development, and commercialization of graphene (a two-dimensional [it has length and width but no depth] material made of carbon atoms).

You can find out more about the flagship and about graphene here.

The quantum chemistry of nanomedicines

A Jan. 29, 2015 news item on Nanowerk provides an overview of the impact quantum chemical reactions may have on nanomedicines. Intriguingly, this line of query started with computations of white dwarf stars,

Quantum chemical calculations have been used to solve big mysteries in space. Soon the same calculations may be used to produce tomorrow’s cancer drugs.

Some years ago research scientists at the University of Oslo in Norway were able to show that the chemical bonding in the magnetic fields of small, compact stars, so-called white dwarf stars, is different from that on Earth. Their calculations pointed to a completely new bonding mechanism between two hydrogen atoms. The news attracted great attention in the media. The discovery, which in fact was made before astrophysicists themselves observed the first hydrogen molecules in white dwarf stars, was made by UiO’s Centre for Theoretical and Computational Chemistry. They based their work on accurate quantum chemical calculations of what happens when atoms and molecules are exposed to extreme conditions.

A Jan. 29, 2015 University of Oslo press release by Yngve Vogt, which originated the news item, offers a substantive description of molecules, electrons, and more for those of us whose last chemistry class is lost in the mists of time,

The research team is headed by Professor Trygve Helgaker, who for the last thirty years has taken the international lead on the design of a computer system for calculating quantum chemical reactions in molecules.

Quantum chemical calculations are needed to explain what happens to the electrons’ trajectories within a molecule.

Consider what happens when UV radiation sends energy-rich photons into your cells. This increases the energy level of the molecules. The outcome may well be that some of the molecules break up. This is exactly what happens when you sun-bathe.

“The extra energy will affect the behaviour of electrons and can destroy the chemical bonding within the molecule. This can only be explained by quantum chemistry. The quantum chemical models are used to produce a picture of the forces and tensions at play between the atoms and the electrons of a molecule, and of what is required for a molecule to dissociate,” says Trygve Helgaker.

The absurd world of the electrons

The quantum chemical calculations solve the Schrödinger equation for molecules. This equation is fundamental to all chemistry and describes the whereabouts of all electrons within a molecule. But here we need to pay attention, for things are really rather more complicated than that. Your high school physics teacher will have told you that electrons circle the atom. Things are not that simple, though, in the world of quantum physics. Electrons are not only particles, but waves as well. The electrons can be in many places at the same time. It’s impossible to keep track of their position. However, there is hope. Quantum chemical models describe the electrons’ statistical positions. In other words, they can establish the probable location of each electron.

The results of a quantum chemical calculation are often more accurate than what is achievable experimentally.

Among other things, the quantum chemical calculations can be used to predict chemical reactions. This means that the chemists will no longer have to rely on guesstimates in the lab. It is also possible to use quantum chemical calculations in order to understand what happens in experiments.

Enormous calculations

The calculations are very demanding.

“The Schrödinger equation is a highly complicated, partial differential equation, which cannot be accurately solved. Instead, we need to make do with heavy simulations”, says researcher Simen Kvaal.

The computations are so demanding that the scientists use one of the University’s fastest supercomputers.

“We are constantly stretching the boundaries of what is possible. We are restricted by the available machine capacity,” explains Helgaker.

Ten years ago it took two weeks to carry out the calculations for a molecule with 140 atoms. Now it can be done in two minutes.

“That’s 20,000 times faster than ten years ago. The computation process is now running 200 times faster because the computers have been doubling their speed every eighteen months. And the process is a further 100 times faster because the software has been undergoing constant improvement,” says senior engineer Simen Reine.

This year the research group has used 40 million CPU hours, of which twelve million were on the University’s supercomputer, which is fitted with ten thousand parallel processors. This allows ten thousand CPU hours to be over and done with in 60 minutes.

“We will always fill the computer’s free capacity. The higher the computational capacity, the bigger and more reliable the calculations.”

Thanks to ever faster computers, the quantum chemists are able to study ever larger molecules.

Today, it’s routine to carry out a quantum chemical calculation of what happens within a molecule of up to 400 atoms. By using simplified models it is possible to study molecules with several thousand atoms. This does, however, mean that some of the effects within the molecule are not being described in detail.

The researchers are now getting close to a level which enables them to study the quantum mechanics of living cells.

“This is exciting. The molecules of living cells may contain many hundred thousand atoms, but there is no need to describe the entire molecule using quantum mechanical principles. Consequently, we are already at a stage when we can help solve biological problems.”

There’s more from the press release which describes how this work could be applied in the future,

Hunting for the electrons of the insulin molecule

The chemists are thus able to combine sophisticated models with simpler ones. “This will always be a matter of what level of precision and detail you require. The optimal approach would have been to use the Schrödinger equation for everything.”

By way of compromise they can give a detailed description of every electron in some parts of the model, while in other parts they are only looking at average numbers.

Simen Reine has been using the team’s computer program, while working with Aarhus University [Finland], on a study of the insulin molecule. An insulin molecule consists of 782 atoms and 3,500 electrons.

“All electrons repel each other, while at the same time being pulled towards the atomic nuclei. The nuclei also repel each other. Nevertheless, the molecule remains stable. In order to study a molecule to a high level of precision, we therefore need to consider how all of the electrons move relative to one another. Such calculations are referred to as correlated and are very reliable.”

A complete correlated calculation of the insulin molecule takes nearly half a million CPU hours. If they were given the opportunity to run the program on the entire University’s supercomputer, the calculations would theoretically take two days.

“In ten years, we’ll be able to make these calculations in two minutes.”

Medically important

“Quantum chemical calculations can help describe phenomena at a level that may be difficult to access experimentally, but may also provide support for interpreting and planning experiments. Today, the calculations will be put to best use within the fields of molecular biology and biochemistry,” says Knut Fægri [vice-rector at the University of Oslo].

“Quantum chemistry is a fundamental theory which is important for explaining molecular events, which is why it is essential to our understanding of biological systems,” says [Associate Professor] Michele Cascella.

By way of an example, he refers to the analysis of enzymes. Enzymes are molecular catalysts that boost the chemical reactions within our cells.

Cascella also points to nanomedicines, which are drugs tasked with distributing medicine round our bodies in a much more accurate fashion.

“In nanomedicine we need to understand physical phenomena on a nano scale, forming as correct a picture as possible of molecular phenomena. In this context, quantum chemical calculations are important,” explains Michele Cascella.

Proteins and enzymes

Professor K. Kristoffer Andersson at the Department of Biosciences uses the simpler form of quantum chemical calculations to study the details of protein structures and the chemical atomic and electronic functions of enzymes.

“It is important to understand the chemical reaction mechanism, and how enzymes and proteins work. Quantum chemical calculations will teach us more about how proteins go about their tasks, step by step. We can also use the calculations to look at activation energy, i.e. how much energy is required to reach a certain state. It is therefore important to understand the chemical reaction patterns in biological molecules in order to develop new drugs,” says Andersson.

His research will also be useful in the search for cancer drugs. He studies radicals, which may be important to cancer. Among other things, he is looking at the metal ions function in proteins. These are ions with a large number of protons, neutrons and electrons.

Photosynthesis

Professor Einar Uggerud at the Department of Chemistry has uncovered an entirely new form of chemical bonding through sophisticated experiments and quantum chemical calculations.

Working with research fellow Glenn Miller, Professor Uggerud has found an unusually fragile key molecule, in a kite-shaped structure, consisting of magnesium, carbon and oxygen. The molecule may provide a new understanding of photosynthesis. Photosynthesis, which forms the basis for all life, converts CO2 into sugar molecules.

The molecule reacts so fast with water and other molecules that it has only been possible to study in isolation from other molecules, in a vacuum chamber.

“Time will tell whether the molecule really has an important connection with photosynthesis,” says Einar Uggerud.

I’m delighted with this explanation as it corrects my understanding of chemical bonds and helps me to better understand computational chemistry. Thank you University of Oslo and Yngve Vogt.

Finally, here’s a representation of an insulin molecule as understood by quantum computation,

QuantumInsulinMolecule

INSULIN: Working with Aarhus University, Simen Reine has calculated the tensions between the electrons and atoms of an insulin molecule. An insulin molecule consists of 782 atoms and 3,500 electrons. Illustration: Simen Reine-UiO