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TU Delft
SCIENCE Sandstone gets CT-scan
SHORT
The new CT-scanner at the Faculty of Civil Engineering and Geosciences was made for humans. But it dissects rocks just as easily. Lab technician Joost van Meel puts a composite cylinder on the scanner bed. He leaves the room and switches on the scanner. Inside the machine, and invisible to the eye, two heavy X-ray sources rotate around the sample, scanning every millimetre of it from every angle. Meanwhile, the bed slides slowly through the scanner hole. The scanner makes 64 slides per millimetre while the resolution in the other directions is about 0.25 millimetres. Van Meel conjures up the image of a sandstone core in the cylinder. There is what seems to be a wet stain entering the core from one side. Measuring the penetration speed of water through sandstone under pressures up to 300 bars is one example of the many applications that the scanner has. "It can help you finding the best ways to get oil out of a certain
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Molten salt
CEGS’s scanner probes for oil rather than for organs. (Photo: Jos Wassink)
rock", says Dr Karl Heinz Wolf, associate professor at the Faculty of CEGS. If, for example, you want to produce oil from chalk, a very fine grained type of limestone, you may consider applying pressure or adding acid to detach the oil from the surrounding rock. The CT scanner shows what happens in the rock: wormhole type channels are formed. Do chemical reactions occur? Do different generations of wormholes form? Such knowledge may be used to improve the geophysical models.
Wolf, who played an important role in acquiring the scanner for the university, said he was very glad with it. "This is an asset for the experimental geoscience and engineering research", he said. The role in education is limited to students reading the scans and trying to understand what information can be extracted from them. (JW) delta.tudelft.nl/30372
TU Delft is leading the four-year programme SAMOFAR (Safety Assessment of the Molten Salt Fast Reactor) to examine and validate the safety and waste principles of molten salt reactors, a potentially cleaner and safer source of nuclear energy. SAMOFAR is a €5 million European Union programme involving 11 partners from both science and industry. (ABG) delta.tudelft.nl/30442
Reuse Olympics
TU Delft Sports Engineering Institute and the Royal Netherlands Society of Engineers (KIVI) invited five speakers to share their Olympic expertise during a symposium at the Faculty of Architecture on September 14, 2015. They outlined challenges and solutions for creating the huge infrastructures needed to host the world's largest sporting event. All speakers agreed on the need for integrating multiple perspectives and interdisciplinarity to optimise the aftereffects on the host city. (MV) delta.tudelft.nl/30423
Hanson team proved Einstein wrong The experiment that Ronald Hanson and his team performed is regarded as the final nail in the coffin of locality and realism as the basis of physics. Instead, quantum weirdness rules. Their publication is online at arXiv.org. The test set-up spanned the campus. One diamond containing an electron with spin was located in the physics building, the other one at the reactor centre 1.3 kilometres further away. Both diamonds were hit by randomly emitted microwave pulses. As a consequence, the electrons in the diamonds emitted photons that were entangled with the electrons. The photons then travel-
led through optic fibre to a detector at the southern corner of the electrical engineering building – about halfway for both diamonds. If the two photons arrived simultaneously at the detectors halfway, the two distant electrons were entangled. What follows is a random interrogation of both electron spins by laser pulses that force the electron spins into an excited state, whether or not in combination with microwave pulses that rotate the electron spin 90 degrees. The outcome takes the form of light or no light emissions from the electron spins. The statistics of the measurements should reveal whether or not the electron spins show more coherence than could be anticipated by chance. In the latest publication on arXiv. org the team writes just a few entanglements happened every hour.
So for their 245 measurements to occur, it was quite a wait. The result means that entanglement at a distance is real. Or, as Hanson explained at the presentation of his experiment last year: "As soon as you perform a measurement, that determines the state of each particle. No communication is necessary to achieve this: the effect is instantaneous. You just have to dare to let go of the idea of locality." (JW) delta.tudelft.nl/30435
After match: living in the stadium. (Image: Reinders Kirchert)
Self-assembly
Prof. Jan van Esch (Chemical Engineering, Faculty of Applied Sciences) and his team have achieved transient self-assembly with chemical fuels. This process, using synthetic fibres, is a replication of an important process found in nature. In the lab, it has potential in soft materials, like soft-robotics. In transient self-assembly thousands of molecules cluster together. The links are only temporary, as some molecules deactivate and leave the cluster. Van Esch explained in Science (September 4, 2015) that there has to be a continuous influx of newly activated molecules (fuel) to keep the cluster alive. (AC) delta.tudelft.nl/30421