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  • richardmitnick 11:37 am on February 6, 2021 Permalink | Reply
    Tags: "New microscopy concept enters into force", , ETH Zürich (CH), , Scanning Force Microscopy,   

    From ETH Zürich (CH): “New microscopy concept enters into force” 

    From ETH Zürich (CH)

    05.02.2021

    The first demonstration of an approach that inverts the standard paradigm of scanning probe microscopy raises the prospect of force sensing at the fundamental limit.

    1
    Configuration of the inverted scanning force microscope.Credit: Alexander Eichler, ETH Zürich)

    The development of scanning probe microscopes in the early 1980s brought a breakthrough in imaging, throwing open a window into the world at the nanoscale. The key idea is to scan an extremely sharp tip over a substrate and to record at each location the strength of the interaction between tip and surface. In scanning force microscopy, this interaction is — as the name implies — the force between tip and structures on the surface. This force is typically determined by measuring how the dynamics of a vibrating tip changes as it scans over objects deposited on a substrate. A common analogy is tapping a finger across a table and sensing objects placed on the surface. A team led by Alexander Eichler, Senior Scientist in the group of Prof. Christian Degen at the Laboratory for Solid State Physics, turned this paradigm upside down. Writing in Physical Review Applied, they report the first scanning force microscope in which the tip is at rest while the substrate with the samples on it vibrates.

    Tail wagging the dog

    Doing force microscopy by ‘vibrating the table under the finger’ may look like making the entire procedure a whole lot more complicated. In a sense it does. But mastering the complexity of this inverted approach comes with great payoff. The new method promises to push the sensitivity of force microscopy to its fundamental limit, beyond what can be expected from further improvements of the conventional ‘finger tapping’ approach.

    The key to the superior sensitivity is the choice of substrate. The ‘table’ in the experiments of Eichler, Degen and their co-​workers is a perforated membrane made of silicon nitride, a mere 41 nm in thickness. Collaborators of the ETH physicists, the group of Albert Schliesser at the U Copenhagen[Københavns Universitet] (DK), have established these low-​mass membranes as outstanding nanomechanical resonators with extreme ‘quality factors’. Specifically, once the membrane is tipped on, it vibrates millions of times, or more, before coming to rest. Given these exquisite mechanical properties, it becomes advantageous to vibrate the ‘table’ rather than the ‘finger’. At least in principle.

    New concept put to practice

    Translating this theoretical promise into experimental capability is the objective of an ongoing project between the groups of Degen and Schliesser, with theory support from Dr. Ramasubramanian Chitra and Prof. Oded Zilberberg of the Institute for Theoretical Physics at ETH Zürich. As a milestone on that journey, the experimental teams have now demonstrated that the concept of membrane-​based scanning force microscopy works in a real device.

    3
    Photograph of the experimental setup. The separation of the islands is around half a millimetre.
    Credit: David Hälg and Shobhna Misra, ETH Zürich.

    In particular, they showed that neither loading the membrane with samples nor bringing the tip to within a distance of a few nanometres compromises the exceptional mechanical properties of the membrane. However, once the tip approaches the sample even closer, the frequency or amplitude of the membrane changes. To be able to measure these changes, the membrane features not only an island where tip and sample interact, but also a second one — mechanically coupled to the first — from where a laser beam can be partially reflected, to provide a sensitive optical interferometer.

    Quantum is the limit

    6
    Topographic image of gold nanoparticles with a nominal average diameter of 50 nm and tobacco mosaic virus samples (scale bar: 200 nm). From doi: 10.1103/PhysRevApplied.15.L021001 [above].

    Putting this setup to work, the team successfully resolved gold nanoparticles and tobacco mosaic viruses. These images serve as a proof of principle for the novel microscopy concept, but they do not yet push the capabilities into new territory. But the destination is just there. The researchers plan to combine their novel approach with a technique known as magnetic resonance force microscopy (MRFM), to enable magnetic resonance imaging (MRI) with a resolution of single atoms, thus providing unique insight, for example, into viruses.

    Atomic-​scale MRI would be another breakthrough in imaging, combining ultimate spatial resolution with highly specific physical and chemical information about the atoms imaged. For the realization of that vision, a sensitivity close to the fundamental limit given by quantum mechanics is needed. The team is confident that they can realise such a ‘quantum-​limited’ force sensor, through further advances in both membrane engineering and measurement methodology. With the demonstration that membrane-​based scanning force microscopy is possible, the ambitious goal has now come one big step closer.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
  • richardmitnick 6:01 pm on February 3, 2021 Permalink | Reply
    Tags: "Research investigates variability of the blazar Mrk 421", , , , , ETH Zürich (CH), FACT Čerenkov Telescope,   

    From ETH Zürich (CH) via phys.org: “Research investigates variability of the blazar Mrk 421” 

    From ETH Zürich (CH)

    via


    phys.org

    February 2, 2021
    Tomasz Nowakowski

    1
    Sloan Digital Sky Survey image of blazar Markarian 421. Credit: Sloan Digital Sky Survey.

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude2,788 meters (9,147 ft).

    Apache Point Observatory, near Sunspot, New Mexico Altitude 2,788 meters (9,147 ft).

    Astronomers from Switzerland and Germany have performed multiwavelength observations of a high-synchrotron-peaked blazar known as Mrk 421. Results of this observational campaign provide more insights into the variability of gamma-ray emission from this source. The study was published January 26 [The relentless variability of Mrk 421 from the TeV to the radio]

    Blazars are very compact quasars associated with supermassive black holes at the centers of active, giant elliptical galaxies. In general, blazars belong to a larger group of active galaxies that host active galactic nuclei (AGN), and their characteristic features are relativistic jets pointed almost exactly toward the Earth. Based on their optical emission properties, astronomers divide blazars into two classes: flat-spectrum radio quasars (FSRQs) that feature broad, prominent optical emission lines, and BL Lacertae objects (BL Lacs), which do not.

    Some FSRQs are high-synchrotron-peaked (HSP) sources as their synchrotron peak is above 1,000 THz in the rest frame. Observations show that particles are efficiently accelerated up to very high energies (VHEs) in the jets of HSPs, which makes such sources very interesting for astronomers studying extreme blazars.

    At a redshift of about 0.031, Mrk 421 is a HSP blazar with a low-energy synchrotron component peaking above 100,000 THz. It showcases bright and persistent GeV and TeV emission with frequent flaring activities. Previous observations have shown that gamma-ray emission from Mrk 421 is rapidly variable and its origin is still debated.

    In order to shed more light on the origin of this emission, a team of astronomers led by Axel Arbet-Engels of ETH Zürich (CH) decided to analyze observational data obtained between December 2012 and April 2018, using nine different instruments spanning from radio to gamma-ray band.

    “We used 5.5 years of unbiased observing campaign data, obtained using the FACT telescope and the Fermi LAT detector at TeV and GeV energies, the longest and densest so far, together with contemporaneous multi-wavelength observations, to characterize the variability of Mrk 421 and to constrain the underlying physical mechanisms,” the researchers wrote in the paper.

    FACT The First G-APD Čerenkov Telescope, on the Canary Island of La Palma (ES).

    NASA/Fermi LAT.


    NASA/Fermi Gamma Ray Space Telescope.

    The study found that the strongest variations of Mrk 421 occur in the hard X-rays and in the TeV energy band. It turned out that X-ray and flares in the TeV energy band are very well correlated. The TeV and X-ray fluxes measured simultaneously were also found to be correlated.

    According to the paper, the average lag between the TeV and X-ray variations is at a level of less than 0.6 days. The variations in the GeV energy band appear to be strongly and widely correlated with optical and radio variability. It was found that the radio variations are lagging these in the GeV band by 30 to 100 days.

    Summing up the results, the astronomers concluded that X-ray and TeV emissions are driven by the same population of high-energy particles. They added that such variability could be caused by variations of the electron maximal energy, or by, for instance, the magnetic field affecting electrons and protons.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
  • richardmitnick 1:55 pm on January 29, 2021 Permalink | Reply
    Tags: , , , ETH Zürich (CH), , , Kimberlites and oceanic islands share the same source material., Most kimberlites also originate in the bottommost layer of the mantle., Some locations on the Earth’s surface have “witnesses” that provide direct information about the lower mantle., The oldest kimberlites are more than 2 billion years old- found primarily in the ancient parts of the continents called cratons., The seismic data can reveal that lava from certain volcanic islands such as Hawaii must originate at a tremendous depth., Volcanic rocks, Witnesses to Earth’s early history"   

    From ETH Zürich (CH): “Witnesses to Earth’s early history” 

    From ETH Zürich (CH)

    29.01.2021
    Felix Würsten

    Determining the composition of rock in the deepest layer of the Earth’s mantle is impossible to do directly. But thanks to isotope measurements of volcanic rocks, ETH researchers are now able to show that the mantle is still home to material from the planet’s earliest days.

    1
    Microscopic image of a kimberlite from Somerset Island (Canada). Like other kimberlites, this rock originates from the deepest layers of the Earth’s mantle. (Image: A. Giuliani / ETH Zürich)

    What exactly are the deepest parts of the Earth made of? Geoscientists apply highly sophisticated techniques in pursuit of this question. Seismic waves, for example, help them map the structures in the Earth’s interior. The scientists can then draw conclusions regarding the composition of these structures and then make hypotheses about their formation.

    In addition, some locations on the Earth’s surface have “witnesses” that provide direct information about the lower mantle. The seismic data can reveal, say, that lava from certain volcanic islands such as Hawaii must originate at a tremendous depth. Over a long period of time, the hot material raised up from the deepest regions of the mantle, close to the core, until it reached the surface of the Earth.

    More help from a combination of data

    Chemical analysis of these volcanic rocks allows for conclusions about the composition of the very bottom of Earth’s mantle. But there’s just one thing: the oldest of these volcanic islands are just about 150 million years old, which is quite young in the Earth history. Using these rocks alone to trace the 4.5 billion years of mantle evolution does not go very far.

    But fortunately another source sheds light on this subject. Most kimberlites also originate in the bottommost layer of the mantle and they are much older than volcanic islands in the oceans. The oldest kimberlites are more than 2 billion years old, found primarily in the ancient parts of the continents, called cratons.

    Very long half-​lives

    Andrea Giuliani, Swiss National Science Foundation Ambizione Fellow, and postdoctoral scholar Angus Fitzpayne, both in the Department of Earth Sciences at ETH Zürich, joined with colleagues from the US and Australia in collecting data on kimberlites, adding their own measurements to the mix. They focused on the radiogenic isotopes of three elements: strontium, neodymium and hafnium. These make it possible to reconstruct the composition of the source material of these rocks throughout the Earth history, since their radiogenic isotopes have very long half-​lives.

    With these data, Giuliani and coworkers demonstrate that kimberlites and oceanic islands share the same source material. Now they have an answer to a question that geologists have been arguing about for a long, long time, what is the origin of this deep source? Some geologists maintain that this must be ancient material from the very beginnings of the Earth; others believe that it was formed later by upheaval in the mantle.

    Similarity to chondritic meteorites

    From the kimberlite data, Giuliani and colleagues have extrapolated what the isotopic composition of the tested rocks must have been 4.5 billion years ago. Their work has led them to the realisation that the rocks’ source material must be similar in composition to the chondritic meteorites that formed the Earth. In other words, the deepest layers of the mantle contain material effectively unchanged since the beginnings of the Earth’s history.

    Giuliani acknowledges that their results, recently published in the journal PNAS, are still somewhat speculative. “The oldest rocks we looked at are about 2 billion years old,” he explains. “That means our extrapolations back in time are still a bit uncertain.” As a next step, Giuliani hopes to incorporate other, older kimberlites as well as other rock types into the analysis to further refine our understanding of the mantle evolution.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
  • richardmitnick 1:47 pm on January 22, 2021 Permalink | Reply
    Tags: "How our planets were formed", A key role here is played by the snow line which formed at a certain distance to the still very young sun., ETH Zürich (CH), Just outside the snow line some of the water vapour condensed onto grains of dust which clumped together to form the first planetesimals., , Snow line moved outwards, Terrestrial planets versus gas and ice giants: A new theory explaining why the inner solar system is so different to the outer regions runs counter to the prevailing wisdom., Two waves of formation at different points in time, Within the snow line water existed as vapour.   

    From ETH Zürich (CH): “How our planets were formed” 

    From ETH Zürich (CH)

    21.01.2021
    Barbara Vonarburg

    Terrestrial planets versus gas and ice giants: A new theory explaining why the inner solar system is so different to the outer regions runs counter to the prevailing wisdom. The theory was proposed by an international research group with ETH Zürich’s participation.

    1
    Formation of the solar system in two different planetary populations: the inner rocky planets formed earlier than the outer gas and ice giants. Credit: Mark A. Garlick / markgarlick.com .

    Mercury, Venus, Earth and Mars in the inner solar system are relatively small, dry planets, unlike Jupiter, Saturn, Uranus and Neptune in the outer regions, planets that contain much greater quantities of volatile elements. “In the last few years, we’ve also discovered another major difference between the two parts of the solar system,” says Maria Schönbächler, Professor at the Institute of Geochemistry and Petrology at ETH Zürich, continuing: “Meteorites have a different ‘fingerprint’ depending on whether they originated in the inner or the outer solar system.” Where they originate determines the meteorites’ isotope content. Isotopes are distinct atoms of a given element, which all share the same number of protons in their nuclei but vary in the number of neutrons.

    2
    Image showing positions and names of planets in the Solar System. Credit: Planets2013-fa.svg

    The current explanation for the differences in the chemical composition of planets and meteorites is as follows: 4.5 billion years ago, as the solar system was forming from a disc of gas and dust, the planet Jupiter was the first to develop. It split the disc into an inner and an outer region and blocked the exchange of materials between the two.

    “As a group of researchers, collaborating across a range of disciplines, we have developed a new model of planet formation. It provides an alternative explanation for the differences in isotopes, and Jupiter doesn’t play a role,” Schönbächler explains. The idea for the new theory came about through collaboration between researchers from ETH and the University of Zürich at the National Centre of Competence in Research (NCCR) PlanetS, of which Schönbächler is a member. Now the international team is publishing its work in the journal Science.

    Two waves of formation at different points in time

    “We used computer simulations to calculate what might have happened in the early solar system,” says Tim Lichtenberg from the University of Oxford (UK), the study’s lead author and a former member of the NCCR PlanetS, who received his PhD degree at ETH.

    According to these simulations, the inner and outer solar system formed in two separate waves at two different times. Extremely early on, when the original disc of dust and gas as well as the sun were still forming, the first building blocks of the inner planets appeared – experts refer to these pieces, which measure about 100 kilometres, as planetesimals. A key role here is played by the snow line, which formed at a certain distance to the still very young sun. Within the snow line, water existed as vapour, while water beyond it turned into ice crystals. Just outside the snow line some of the water vapour condensed onto grains of dust, which clumped together to form the first planetesimals.

    “These were extremely rich in water,” Lichtenberg explains, adding: “This is quite a surprise, because it means the Earth should have held much more water and so today ought to look more like a comet.” Here, too, the new theory offers an explanation: the dust disc contained the radioactive isotope aluminium-​26, which the planetary building blocks inherited. It has a half-​life of 700,000 years and unleashes a large amount of energy as it decays – enough to heat planetesimals from the inside and melt them. This led to the formation of iron cores and the evaporation of water and other volatile elements.

    Snow line moved outwards

    “In our model, after the first planetesimals formed in the inner solar system, nothing happened for about a half a million years,” Lichtenberg explains. Then there came a second wave of planetesimal formation, only this time in the outer solar system. With the warming up of the gas and dust disc, the snow line had moved outwards, and dust particles moving towards the sun were held up at the new snow border. The researchers describe it as a “traffic jam”, and it gave rise to new planetesimals. “The formation of the planets in the outer solar system started later, but also finished more quickly; the inner planets needed a lot longer,” Lichtenberg says. Because the second process began later, a large portion of the radioactive aluminium-​26 had already decayed, meaning a smaller quantity of volatile elements evaporated away. As a result, the outer region saw the formation of gas and ice giants like Jupiter, Saturn or Uranus.

    New combination of current data

    “Our model also sheds new light on the growth of the original planetesimals in the inner solar system, which then continued until they formed the terrestrial planets like our Earth,” Schönbächler says. According to the model, the initial phase was dominated by collisions among the planetesimals. Later, the gravity of these bodies caused them to attract and accumulate dust particles in a process experts call “pebble accretion”. Another phase of collisions followed until the end of Earth’s formation process, when it collided with one last large chunk. This impact caused the young planet to eject material that ultimately formed the moon. The simulations also illustrate how the planets migrated closer to the sun as they were forming, before settling into the orbits we see today.

    “In our study, we propose an overall scenario that reproduces the composition and the formation history of the solar system,” Lichtenberg says. And indeed, the computer calculations correspond to data from meteorite analysis and astronomical observations. “This combination of current meteorite data and development models is new,” Schönbächler says, “and I’m delighted at how well everything lines up.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
  • richardmitnick 12:18 pm on January 19, 2021 Permalink | Reply
    Tags: "Solar activity reconstructed over a millennium", Accelerator mass spectrometry, , , ETH Zürich (CH), Radioactive carbon in tree rings using the C14 method for data.., Tree-​ring archives from England and Switzerland   

    From ETH Zürich (CH): “Solar activity reconstructed over a millennium” 

    From ETH Zürich (CH)

    19.01.2021
    Oliver Morsch

    An international team of researchers led by ETH Zürich has reconstructed solar activity back to the year 969 using measurements of radioactive carbon in tree rings. Those results help scientists to better understand the dynamics of the sun and allow more precise dating of organic materials using the C14 method.


    Solar activity reconstructed over a millennium
    A team of researchers has reconstructed solar activity back to the year 969. (Video: ETH Zürich)

    What goes on in the sun can only be observed indirectly. Sunspots, for instance, reveal the degree of solar activity – the more sunspots are visible on the surface of the sun, the more active is our central star deep inside. Even though sunspots have been known since antiquity, they have only been documented in detail since the invention of the telescope around 400 years ago. Thanks to that, we now know that the number of spots varies in regular eleven-​year cycles and that, moreover, there are long-​lasting periods of strong and weak solar activity, which is also reflected in the climate on Earth.

    However, how solar activity developed before the start of systematic records has so far been difficult to reconstruct. An international research team led by Hans-​Arno Synal and Lukas Wacker of the Laboratory of Ion Beam Physics at ETH, which included the Max Planck Institute for Solar System Research [Max-Planck-Institut für Sonnensystemforschung](DE) in Göttingen and Lund University [Lunds universitet] (SE), has now traced back the sun’s eleven-​year cycle all the way to the year 969 using measurements of the concentration of radioactive carbon in tree rings. At the same time, the researchers have thus created an important database for more precise age determination using the C14 method. Their results were recently published in the scientific journal Nature Geoscience.

    Solar activity from tree rings

    To reconstruct solar activity over a millennium with an extremely good time resolution of just one year, the researchers used tree-​ring archives from England and Switzerland. In those tree rings, whose ages can be precisely determined by counting the rings, there is a tiny fraction of radioactive carbon C14, with only one out of every 1000 billion atoms being radioactive. From the known half-​life of the C14 isotope – around 5700 years – one can then deduce the concentration of radioactive carbon present in the atmosphere when the growth ring was formed. As radioactive carbon is mainly produced by cosmic particles, which in turn are kept away from the Earth to a greater or lesser extent by the magnetic field of the sun – the more active the sun, the better it shields the Earth – it is possible to deduce solar activity from a change in the concentration of C14 in the atmosphere.

    2
    Solar activity over the last 1000 years (blue, with error interval in white), sunspot records (red curve) going back less than 400 years. The background shows a typical eleven-​year cycle of the sun. Credit: ETH Zürich.

    Better results through modern detection techniques

    Precise measurements of a change in that already very small concentration, however, resemble the search for a grain of dust on a needle in a huge haystack. “The only measurements of that kind were made in the 80’s and 90’s”, says Lukas Wacker, “but only for the last 400 years and using the extremely laborious counting method”. In that method, radioactive decay events of C14 in a sample are directly counted using a Geiger counter, which requires a relatively large amount of material and, owing to the long half-​life of C14, even more time. “Using modern accelerator mass spectrometry we were now able to measure the C14 concentration to within 0.1 percent in just a few hours with tree-​ring samples that were a thousand times smaller”, adds PhD student Nicolas Brehm, who was responsible for those analyses.

    In accelerator mass spectrometry, C14 and C12 atoms (the “normal”, non-​radioactive carbon; C14, by contrast, contains two additional neutrons in its nucleus) of the tree material are first electrically charged and then accelerated by an electric potential of several thousand volts, after which they are sent through a magnetic field. In that magnetic field the two carbon isotopes, which have different masses, are deflected to different degrees and can thus be counted separately. To eventually obtain the desired information on solar activity from that raw data, the researchers have to perform some intricate statistical analysis on it and further process the results using computer models.

    3
    With the new instruments developed at ETH (right), researchers can measure tiny changes of a few tenths of a percent in that concentration and reconstruct pasts solar activity from them. Credit: ETH Zürich.

    Regular eleven-​year cycle over a millennium

    This procedure enabled the researchers to seamlessly reconstruct solar activity from 969 to 1933. From that reconstruction they could confirm the regularity of the eleven-​year cycle as well as the fact that the amplitude of that cycle (by how much the solar activity goes up and down) is also smaller during long-​lasting solar minima. Such insights are important for a better understanding of the internal dynamics of the sun. The measurement results also allowed a confirmation of the solar energetic proton event of 993. In such an event, highly accelerated protons that reach the Earth during a solar flare cause a slight overproduction of C14. Moreover, the research team also found evidence of two further, as yet unknown events in 1052 and 1279. This could indicate that such events – which can severely disturb electronic circuits on Earth and in satellites – happen more frequently than previously thought.

    More precise dating by the C14 method

    As tree ring archives exist for the past 14’000 years, in the near future the researchers want to use their method to determine the yearly C14 concentrations all the way back to the end of the last ice age. As a kind of “extra”, the data in the new study can be used for dating organic material much more precisely using the C14 method and have already been included in the latest edition of the internationally recognized radio carbon calibration curves (IntCal). “ETH had not been involved in that reference database before”, says Lukas Wacker, “but with our new results we have now contributed a third of the measurements in one go.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
  • richardmitnick 5:45 pm on January 4, 2021 Permalink | Reply
    Tags: "ETH researchers compute turbulence with artificial intelligence", , ETH Zürich (CH), Navier-​Stokes equations, Researchers use models in their simulations so that they do not have to calculate every detail to maintain accuracy., , The modelling and simulation of turbulent flows is crucial for designing cars and heart valves; predicting the weather; and even retracing the birth of a galaxy., The physicist Richard Feynman counted turbulence among the most important unsolved problems in classical physics., The researchers developed new reinforcement learning (RL) algorithms and combined them with physical insight to model turbulence.   

    From ETH Zürich (CH): “ETH researchers compute turbulence with artificial intelligence” 

    From ETH Zürich (CH)

    04.01.2021
    Simone Ulmer

    For the first time, researchers at ETH Zürich have successfully automated the modelling of turbulence. Their project relies on fusing reinforcement learning algorithms with turbulent flow simulations on the CSCS supercomputer “Piz Daint”.

    1
    Vortical structures at the onset of transition to turbulence by Taylor Green vortices (Graphic: CSE/lab ETH Zürich)

    The modelling and simulation of turbulent flows is crucial for designing cars and heart valves, predicting the weather, and even retracing the birth of a galaxy. The Greek mathematician, physicist and engineer Archimedes occupied himself with fluid mechanics some 2,000 years ago, and to this day, the complexity of fluid flows is still not fully understood. The physicist Richard Feynman counted turbulence among the most important unsolved problems in classical physics, and it remains an active topic for engineers, scientists and mathematicians alike.

    Engineers have to consider the effects of turbulent flows when building an aircraft or a prosthetic heart valve. Meteorologists need to account for them when they forecast the weather, as do astrophysicists when simulating galaxies. Consequently, researchers from these communities have been modelling turbulence and performing flow simulations for more than 60 years.

    Turbulent flows are characterized by flow structures spanning a broad range of spatial and temporal scale. There are two major approaches for simulating these complex flow structures: One is direct numerical simulation (DNS), and the other is large eddy simulation (LES).

    Flow simulations test the limits of supercomputers

    DNS solves the Navier-​Stokes equations, which are central to the description of flows, with a resolution of billions and sometimes trillions of grid points. DNS is the most accurate way to calculate flow behaviour, but unfortunately it is not practical for most real-​world applications. In order to capture the details of these turbulent flows, they require far more grid points than can be handled by any computer in the foreseeable future.

    As a result, researchers use models in their simulations so that they do not have to calculate every detail to maintain accuracy. In the LES approach, the large flow structures are resolved, and so-​called turbulence closure models account for the finer flow scales and their interactions with the large scales. However, the correct choice of closure model is crucial for the accuracy of the results.

    Rather art than science

    “Modelling of turbulence closure models has largely followed an empirical process for the past 60 years and remains more of an art than a science”, says Petros Koumoutsakos, professor at the Laboratory for Computational Science and Engineering at ETH Zürich. Koumoutsakos, his PhD student Guido Novati, and former master’s student (now PhD candidate at the University of Zürich) Hugues Lascombes de Laroussilhe have proposed a new strategy to automate the process: use artificial intelligence (AI) to learn the best turbulent closure models from the DNS and apply them to the LES. They published their results recently in Nature Machine Intelligence.

    Specifically, the researchers developed new reinforcement learning (RL) algorithms and combined them with physical insight to model turbulence. “Twenty-​five years ago, we pioneered the interfacing of AI and turbulent flows,” says Koumoutsakos. But back then, computers were not powerful enough to test many of the ideas. “More recently, we also realised that the popular neural networks are not suitable for solving such problems, because the model actively influences the flow it aims to complement,” says the ETH professor. The researchers thus had to resort to a different learning approach in which the algorithm learns to react to patterns in the turbulent flow field.

    3
    Schematic of multi-​agent reinforcement learning (MARL) for modelling. The agents (marked by red cubes) execute a control policy that maximises the similarity between simulations. (Graphic: CSElab/ETH Zürich)

    Automated modelling

    The idea behind Novati’s and Koumoutsako’s novel RL algorithm is to use the grid points that resolve the flow field as AI agents. The agents learn turbulence closure models by observing thousands of flow simulations. “In order to perform such large scale simulations, it was essential to have access to the CSCS supercomputer “Piz Daint”, stresses Koumoutsakos.

    Cray Piz Daint Cray XC50/XC40 supercomputer of the Swiss National Supercomputing Center (CSCS)

    After training, the agents are free to act in the simulation of flows in which they have not been trained before.

    The turbulence model is learned by ‘playing’ with the flow. “The machine ‘wins’ when it succeeds to match LES with DNS results, much like machines learning to play a game of chess or GO” says Koumoutsakos. “During the LES, the AI performs the actions of the unresolved scales by only observing the dynamics of the resolved large scales.” According to the researchers the new method not only outperforms well-​established modelling approaches, but can also be generalised across grid sizes and flow conditions.

    4
    Schematic description of the implemented parallelisation strategy. During training, the working nodes test the control policy under different flow conditions. (Graphic: CSElab/ETH Zürich)

    The critical part of the method is a novel algorithm developed by Novati that identifies which of the previous simulations are relevant for each flow state. The so-​called “Remember and Forget Experience Replay” algorithm has been shown to outperform the vast majority of existing RL algorithms on multiple benchmark problems beyond fluid mechanics, according to the researchers. The team believes that their newly developed method will not only be of importance in the construction of cars and in weather forecasting. “For most challenging problems in science and technology, we can only solve the ‘big scales’ and model the ‘fine’ ones,” says Koumoutsakos. “The newly developed methodology offers a new and powerful way to automate multiscale modelling and advance science through a judicious use of AI.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
  • richardmitnick 11:59 am on December 21, 2020 Permalink | Reply
    Tags: "How a large protein complex assembles in a cell", , , , , ETH Zürich (CH), Metabolic analysis, Protein Sciences   

    From ETH Zürich (CH): “How a large protein complex assembles in a cell” 

    From ETH Zürich (CH)

    21.12.2020
    Peter Rüegg

    1
    The nuclear pore complexes (orange structures), some of which are in the process of assembly, are among the largest protein complexes in a cell. Credit: Olga V Posukh, Institute of Molecular and Cellular Biology, Novosibirsk [RU].

    A team of ETH researchers led by Karsten Weis has developed a method that allows them to study the assembly process for large protein complexes in detail for the first time. As their case study, the biologists chose one of the largest cellular complexes: the nuclear pore complex in yeast cells.

    Cells produce a great number of different protein complexes, each of which is made up of many individual proteins. These protein complexes, like ribosomes for example, are what regulate almost all of a cell’s life-​sustaining biological functions.

    Biologists have succeeded in determining the structure of many of these complexes, but there is less research so far on how the individual proteins assemble and then change over time. Conventional approaches have thus far proved insufficient for studying the exact course that these reactions in cells take, especially where large complexes are concerned.

    A group of ETH researchers led by Karsten Weis and research associate Evgeny Onischenko at ETH Zürich’s Institute of Biochemistry are now presenting a new approach. Their method makes it possible to track the dynamics of protein complex assemblies, even for very large ones, with high temporal resolution. The study has just been published in the journal Cell.

    Inspired by metabolic analysis

    The ETH researchers call their new approach KARMA, which stands for kinetic analysis of incorporation rates in macromolecular assemblies and is based on methods for investigating metabolic processes. Scientists researching metabolism have long used radioactive carbon in their work, e.g., to label glucose molecules, which cells then take up and metabolise. The radioactive labelling enables researchers to track where and at what point in time the glucose molecules or their metabolites appear.

    “This type of research inspired us to apply a similar principle in exploring the reactions that take place in the assembly of protein complexes,” Weis explains. In their approach, the ETH researchers work with labelled amino acids, the fundamental building blocks of proteins, which contain heavier carbon and nitrogen isotopes. In a culture of yeast cells, the team replaces the lightweight amino acids with their heavier counterparts. The yeast uses these heavy amino acids in protein synthesis, which shifts the molecular weight of all newly produced proteins.

    A time scale for the assembly of a complex

    To isolate protein complexes, the researchers remove yeast cells from the cultures at regular intervals and employ mass spectrometry to measure the tiny weight difference between molecules with heavier amino acids and those without. This indicates the age of a protein in a complex. Basically, the older the protein, the earlier it was incorporated into the complex. Based on these age differences, the researchers apply kinetic state models to ultimately reconstruct the precise assembly sequence of a given protein complex.

    As a case study to validate their method, Weis and his team chose the nuclear pore complex in yeast cells. This structure has some 500 to 1,000 elements composed of about 30 different proteins each in multiple copies, thus making it one of the largest known protein complexes.

    Using KARMA, the ETH biochemists were able to obtain a detailed map of which modules are integrated into the structure and when. One of their findings was a hierarchical principle: individual proteins form subunits within a very short time, which then assemble from the centre out to the periphery in a specific sequence.

    Durable scaffold

    “We’ve demonstrated for the first time that some proteins are used very quickly in the assembly of the pore complex, while others are incorporated only after about an hour. That’s an incredibly long time,” Weis says. A yeast cell divides every 90 minutes, which means it would take almost a whole generation to complete assembly of this vital pore complex. Precisely why the assembly of new pores takes so long in relation to the yeast reproduction cycle is not known.

    The ETH researchers also show that once assembly of the pore is complete, parts of the complex are highly stable and durable – in the inner scaffold, for example, hardly any components are replaced during its lifetime. By contrast, proteins at the periphery of the nuclear pore complex are frequently replaced.

    Defective nuclear pores facilitate disease

    Nuclear pores are some of the most important protein complexes in cells, as they are responsible for the exchange of substances and molecules between the cell nucleus and cytoplasm. For example, they transport messenger RNA from the nucleus to the cellular machinery outside the nucleus, which needs these molecules as blueprints for new proteins.

    Moreover, nuclear pores play direct and indirect roles in human disease. Accordingly, changes in the nuclear pore and its proteins can impact the development of conditions like leukaemia, diabetes or neurodegenerative diseases such as Alzheimer’s. “Generally speaking, though, the reasons why pore defects cause these disease patterns are not well understood,” Weis says, explaining that KARMA might help to gain deeper insight into such issues in the future.

    Versatile platform

    “Although we applied KARMA to only one protein complex in this study, we’re excited about its future applications. Our method will now enable us to decipher the sequence of a whole host of biological processes,” Weis says. Their technique can be used, for example, to study molecular events that occur during the infection cycle of viruses such as COVID-​19 and potentially help to find new drug candidates that break that cycle.

    The new method can also be applied to other biological molecules besides proteins, such as RNA or lipids.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
  • richardmitnick 10:11 am on December 18, 2020 Permalink | Reply
    Tags: "How climate change is disrupting ecosystems", , , ETH Zürich (CH), , Novel organisms moving into a new habitat could disturb the ecological balance., The world is getting warmer and warmer – and many organisms native to lower latitudes or elevations are moving higher.   

    From ETH Zürich (CH): “How climate change is disrupting ecosystems” 

    From ETH Zürich (CH)

    17.12.2020
    Peter Rüegg

    When it gets warmer, organisms rise higher from the lowlands. Researchers from ETH and WSL investigated what could happen to plant communities on alpine grasslands if grasshoppers from lower elevations settled there.

    1
    Roesel’s bush-​cricket is one of the many grasshoppers that might migrate to higher elevations once the climate in lower elevations has become unsuitable. Credit: Christian Roesti.

    The world is getting warmer and warmer – and many organisms native to lower latitudes or elevations are moving higher.

    However, novel organisms moving into a new habitat could disturb the ecological balance which has been established over a long period. Plants and herbivores are characterised by long-​term co-​evolution, shaping both their geographic distribution and the characteristics that they display in their occupied sites.

    At higher elevations, this is seen in insect herbivores being generally less abundant and plants in turn being less well defended against herbivores, as a result of lower energy and shorter growing seasons. In contrast, low-​elevation plant species defend themselves against more abundant and diverse herbivores, whether by means of spikes, thorns or hair, or by toxic substances. Climate change could disturb this ecological organisation.

    Grasshoppers translocated to high elevations

    In an experiment, researchers from ETH Zürich, the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) and the University of Neuchâtel investigated what could happen if herbivores – in this case various grasshoppers from middle elevations – settled in alpine meadows at higher elevations and encountered new plant communities there. The study has just been published in the journal Science.

    The researchers translocated various grasshopper species from medium altitudes (1,400 metres above sea level) to three alpine grassland sites at elevations of 1,800, 2,070 and 2,270 metres above sea level, where the ecologists placed the grasshoppers in cages. The local grasshoppers had previously been removed from the experimental areas. The experiment was carried out in the Anzeindaz region in the Vaud Alps.

    In their study, the researchers measured things like how the biomass, structure and composition of the alpine plant communities changed under the influence of the herbivorous insects. The researchers also investigated whether some plant species were more susceptible to herbivory, for instance plants with tougher leaves, or those containing more silica or other constituents such as phenols or tannins.

    Lowland grasshoppers influence alpine community

    The ecologists discovered that the grasshoppers’ feeding behaviour had a clear influence on the vegetation structure and composition of the alpine flora. Alpine communities display clear structure in the organisation of the canopy, with plants with tough leaves at the top, and more shade-​tolerant plants with softer leaves at the bottom. But this natural organisation was disturbed, because the translocated grasshoppers preferred to feed on taller and tough alpine plants, which exhibited functional characteristics such as leaf structure, nutrient content, chemical defence, or growth form similar to those of their previous, lower-​elevation food plants. As a result, the insects reduced the biomass of dominant tough alpine plants, which in turn favoured the growth of small-​stature plant species that herbivores avoid. The overall plant diversity thus increased in the short term.

    “Immigrant herbivores consume specific plants in their new location and this changes and reorganises the competitive interaction between those alpine plant species,” says the study’s first author, Patrice Descombes. Global warming, for example, could disrupt the ecological balance because mobile animals, including many herbivorous insects, can expand their habitat to higher elevations more rapidly than sedentary plants. Herbivorous insects from lower altitudes could therefore have an easy time in alpine habitats with resident plants that are insufficiently or not at all prepared to defend themselves against those new herbivores. This could change the current structure and functioning of alpine plant communities as a whole. Climate change would thus have an indirect impact on ecosystems, in addition to the direct consequences of rising temperatures.

    Important drivers of changed ecosystems

    For Loïc Pellisier, Professor of Landscape Ecology at ETH Zürich and WSL, this indirect effect of climate change on ecosystems is one of the most important things to emerge from the study: “Climate impact research has largely investigated the direct effects of temperature on ecosystems, but these novel interactions that arise between species moving into new habitats could generate important structural modifications. They are important drivers of changed ecosystems in an increasingly warm climate.”

    With their results, the researchers also want to improve models that have so far only inadequately integrated such processes. They also hope that this will improve the prognosis of how climate change will influence the functioning of ecosystems and the services they provide.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
  • richardmitnick 3:08 pm on December 17, 2020 Permalink | Reply
    Tags: "Raising the profile of quantum research", , ETH Zürich (CH), Quantum research is of great importance to ETH Zürich where a significant number of professorships are now investigating quantum physics and quantum technologies.   

    From ETH Zürich (CH): “Raising the profile of quantum research” 

    From ETH Zürich (CH)

    17.12.2020
    Felix Würsten

    Quantum research has long since ceased to be an exclusive domain of physics. The purpose of the new ETH Quantum Center is to ensure ETH Zürich’s various competences and activities in this area are networked even more closely and to raise their public profile.

    1
    Translating the findings of quantum research into specific applications calls for a variety of disciplines to work closely together. Credit: ETH Zürich / Heidi Hostettler)

    Quantum research is one of the most promising research areas being pursued today. The hope is that the principles of quantum mechanics will trigger pioneering breakthroughs in a variety of fields, leading to new applications. These fields include computing, sensor technology, communication and data security.

    Quantum research is of great importance to ETH Zürich, where a significant number of professorships are now investigating quantum physics and quantum technologies. Although the Department of Physics is still home to a majority of quantum scientists, they are playing an increasingly prominent role in other departments as well.

    Foray into new fields

    The expectation of new applications is a major reason why quantum research is gaining a foothold in an increasing number of departments. Harnessing the abstract phenomena of quantum mechanics for specific applications calls for more than just theoretical and experimental physicists. They must also be joined by engineers to attend to the electronics, nanofabrication, new materials or process scalability, and by computer scientists to develop the required programming approaches, without which the new technologies would be useless.

    “The engineers are tasked with translating knowledge into technology,” says Lukas Novotny, Professor of Photonics at the Department of Information Technology and Electrical Engineering. “But at the same time, science is also being advanced by new technologies – now more than ever. This is why it’s essential that physics and the engineering sciences collaborate on quantum research.”

    New degree programme and professorships

    Already well set up to pursue quantum research, ETH Zürich plans to further expand its activities over the next few years. Last autumn, the university launched a new Quantum Engineering Master’s programme. And as part of the ETH+ initiative on quantum research, the recruitment process recently began for two new professorships – one for quantum computing at the Department of Computer Science, the other for experimental quantum technology in collaboration with the Paul Scherrer Institute PSI.

    At the same time, ETH Zürich wants to bring the individual players in this field closer together. For this reason, and also as part of the ETH+ initiative, the university has founded the new ETH Quantum Center, which will bring together ETH’s different disciplines under one roof. In total, 28 professorships from 6 departments and from PSI have already joined the new center. “These numbers are themselves enough to illustrate the how diverse ETH Zürich’s competences in quantum research are,” says Andreas Wallraff, Professor of Solid State Physics. Novotny adds: “The ETH Quantum Center fosters collaboration among researchers from different departments and specialist areas. This enables us to leverage synergies in the development of quantum technologies.”

    But the physicists and electrical engineers are not the only ones expecting great things from closer collaboration: the computer scientists also have high hopes. “Quantum information processing is still in its infancy,” explains Kenny Paterson, Professor of Applied Cryptography. “It has the potential to revolutionise computer science, but the only way to realise this fully is through an interdisciplinary approach.” Especially in his discipline of cryptography, Paterson is hoping that working with physicists will lead to some stimulating insights.

    A distinct public presence

    The center’s initiators are particularly focused on the medium term: with the Swiss National Centre of Competence in Research for Quantum Science and Technology (NCCR QSIT) closing at the end of 2022, the new ETH Quantum Center is now set to take over some of its functions. A top priority is to forge a public presence: “Over the past 20 years, a great many outstanding quantum scientists have come together in various departments at ETH Zürich. In contrast to other universities, their collective presence at ETH has until now been rather understated,” Wallraff says. “If we want to be seen as a major player in this field by national and international research authorities, industry and mainstream media, we need a distinct and recognisable joint presence.”

    A specific example of this is positioning ETH Zürich to be even more successful in securing European funding to pursue quantum technology. And when it comes to future collaborative projects with industry or third-​​party fundraising, ETH will benefit from being able to present the full breadth of its expertise under the umbrella of the new Quantum Center. “ETH already offers first-​​rate quantum research and will position itself globally as an even more powerful driving force in future,” Wallraff says. “We want to work together with the new center to achieve this goal.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
  • richardmitnick 10:43 am on December 14, 2020 Permalink | Reply
    Tags: "Foundations for the energy system of tomorrow", , , ETH Zürich (CH), ReMaP-Renewable Management and Real-​Time Control Platform,   

    From ETH Zürich (CH): “Foundations for the energy system of tomorrow” 

    From ETH Zürich (CH)

    14.12.2020
    Leo Herrmann

    1
    One major challenge: the increased use of solar and wind energy. Credit: Adobestock.

    On the road to a sustainable energy system, technologies for the flexible conversion and efficient storage of energy are becoming increasingly important. To investigate these pressing issues in a realistic way, ETH Zürich, Empa and the Paul Scherrer Institute have been developing ReMaP, a new type of research platform, since 2019. Their initial findings are now available.

    Switzerland’s current energy system is based on imported fossil fuels – gas, petrol and crude oil – but also on a relatively small number of large nuclear and hydroelectric power plants. The electricity these power plants generate reaches consumers via the transmission and distribution grid. Storage lakes, pumped storage and electricity trading with other countries compensate for demand fluctuations, for example between day and night. This system is likely to change fundamentally in the coming decades. The Energy Act, which came into force in 2018, provides for Switzerland to gradually abandon nuclear energy and make greater use of renewable energy sources. It also calls for buildings, industry and mobility to become more energy-​efficient and for net CO2 emissions to fall to zero in 2050. All this could drive demand for electricity even higher, for example through increased use of electric vehicles or heat pumps.

    One challenge is to supplant the share of nuclear energy in the Swiss electricity mix (currently around 35 percent) with renewable energy. Photovoltaics will play a major role, while wind power will play a comparatively smaller role. Both are volatile energy sources because they produce different amounts of power seasonally and depending on the weather. To balance production and demand, technologies are needed that can convert energy into different forms, store it efficiently and then make it available again in the required form. This would allow surplus solar energy in summer to meet increased demand in winter. Flexible conversion and storage technologies, together with digital solutions, would pave the way for more of what is known as sector coupling. For example, hydrogen could then be produced with cheap electricity from photovoltaic systems and used to refuel trucks. The power grid of the future will be more decentralised, flexible and connected.

    An ecosystem for energy research

    The same must apply to the research on which that grid is built. “Anyone who researches a single technology in isolation can draw only limited conclusions,” says John Lygeros, Professor in the Automatic Control Laboratory at ETH Zürich. “There needs to be a connected ecosystem at the research stage to test all kinds of technologies in interaction with each other.” Lygeros is leading one of the ten research projects under the umbrella of ReMaP (Renewable Management and Real-​Time Control Platform), which was presented to the public in June 2019 by ETH Zürich, Empa and the Paul Scherrer Institute (PSI). These institutions boast a wide range of research infrastructure, which the ReMaP project seeks to connect and expand. At present, this infrastructure comprises PSI’s ESI platform and Empa’s ehub platform. While ESI offers, among other things, various technologies for converting electricity into gases, ehub offers the opportunity to study energy flows in the residential, work and mobility sectors. It uses two demonstrators: NEST, a vibrant “vertical neighbourhood” for sustainable construction; and move, a filling station for fuels made from renewable energy.

    At the core of ReMaP lie the control framework and the simulation framework. These enable users to design experiments that establish real-​time connections between any number of physical devices in different locations as well as digital models of devices and then investigate their interactions. Data from the experiments is stored in a central database. Two industrial partners are also involved in developing the necessary software: the company smart grid solutions and the ETH spin-​off Adaptricity. Andreas Haselbacher, a lecturer at the Department of Mechanical and Process Engineering at ETH Zürich and a leader of the ReMaP project, says: “At present, there’s no comparable research platform anywhere in the world that lets us understand both the hardware and software for a range of energy systems at the neighbourhood level.”

    Flexibility as the main objective

    For example, Lygeros and his doctoral student Marta Fochesato, both based at ETH, can use both an electrolyser at PSI and a hydrogen filling station at Empa. In the electrolyser, electricity splits water into hydrogen and oxygen. The two scientists want to optimise the storage of energy in the form of hydrogen. Among other things, they are investigating how to meet a given demand for hydrogen as cost-​effectively as possible. Based on the electrolyser’s efficiency, thermal dynamics and control behaviour, they developed an ideal digital controller: an algorithm that decides minute by minute on the basis of the current electricity price at what the output it should run the electrolyser. Whenever electricity is expensive, hydrogen is produced only if there is an acute need – for example, when a car needs to fill up with hydrogen. When electricity is cheap, the unit produces hydrogen for later use. This keeps the overall electricity costs lower than if the electrolyser sprang into action only to meet demand at any given time. The decisive factor in the experiment is to make the flexible conversion and storage of energy as efficient as possible – which would go a long way towards overcoming the as yet unsolved problem of how to store solar or wind energy across seasons in an economical way. “Integrating infrastructure from different institutions into the same experiment is challenging. ReMaP is unique in its ability to enable collaboration on the scale we see here between ETH, Empa and PSI,” Lygeros says.

    Another ReMaP project focuses on combined heat and power plants. These often consist of a combustion engine and a generator that produces electricity. Whenever they generate a surplus, this can be fed back into the system. Their waste heat from combustion is also put to use, for example to heat buildings. This heat can be made available at up to 750 °C, but the temperature used to heat a building is around 80 °C. This results in a considerable loss of potential, as higher temperatures can be used more flexibly and effectively. Konstantinos Boulouchos and Christian Schürch, from the Aerothermochemistry and Combustion Systems Laboratory at ETH Zürich, are pursuing the approach of using part of the waste heat not for heating, but to drive a chemical reaction in a steam reformer and produce what is known as syngas – a mixture of hydrogen, methane and carbon dioxide. Although this reduces the cogeneration unit’s heat output, it lets the power plant generate a higher-​quality and more flexible form of energy: the syngas produced can serve as seasonal thermal energy storage. The two researchers are now looking to determine the best operating concept for such power plants. The combined heat and power plant they are using for their experiment is located in the ML building on the ETH Zentrum campus, but is connected to the Empa network – and all data is processed there.

    Open for further partners

    ReMaP is still in the process of being set up. These experiments show that there is nothing to prevent other physical systems, such as biogas plants or hydroelectric power plants, from being integrated into the platform even if they are not located at any of the three sites. Project leader Haselbacher looks to the future: “We’re very keen to involve further partners, be they universities, colleges or players from industry.” ReMaP’s stated aim is not only research and development, but also education and communication: the platform is intended to help train the next generation of researchers and specialists, while at the same time offering insights into the energy system of the future to society at large and to decision-​makers in politics and business. Detlef Günther, Vice-​President for Research at ETH Zürich, is pleased: “To make faster progress in research and ultimately make a success of the energy turnaround, we need to work in a connected and interdisciplinary way and involve industry as well as politics and the public. ReMaP is a good example of how the ETH Domain is moving forward on these issues.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ETH Zurich campus
    ETH Zürich (CH) is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich (CH) today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich (CH), underlining the excellent reputation of the university.

     
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