A research group partly financed by the Swiss National Science Foundation (SNSF) is tackling this task.
Discovering the perfect composition of Portland cement, the most common type of cement, was the result of years of experience as well as repeated trials and errors. Emanuela Del Gado, SNSF professor at the Institute for Building Materials of the ETH Zurich, explains that its success is the result of two key factors: its legendary hardness and the availability of its constituent elements.5% of carbon dioxide emissions
Because of the massive ecological impact of cement production, various research groups worldwide are trying to understand why the mixture of this powder and water sets to such hardness.Different densities at the nano level
This is where physicist Emanuela Del Gado enters the scene. She takes a special interest in amorphous materials whose constituents combine in a disorderly manner. Her studies of such materials focus on the nano level. "It is at this level and not at the atomic level that certain material properties are revealed. This also applies to hydrated calcium silicate, a major component of cement which plays an important role in the setting process," she explains.
Until today, all attempts to reduce or partially replace burnt calcium carbonate in the production of cement have resulted in less material hardness. By gaining a better understanding of the mechanisms at the nano level, it is possible to identify physical and chemical parameters and to improve the carbon footprint of concrete without reducing its hardness.(*)E. Masoero, E. Del Gado, R. J.-M. Pellenq, F.-J. Ulm, and S. Yip (2012). Nanostructure and Nanomechanics of Cement: Polydisperse Colloidal Packing. Physical Review Letters. DOI: 10.1103/PhysRevLett.109.155503
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New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State
Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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