Exhibition
Radio waves, microwaves and even light itself are all made of electric and magnetic fields. The classical theory of electromagnetism was completed in the 1860s by James Clerk Maxwell. At the time, Maxwell’s theory was revolutionary, and provided a unified framework to understand electricity, magnetism and optics.
Now, new research led by LSU Department of Physics and Astronomy Assistant Professor Ivan Agullo, with colleagues from the Universidad de Valencia, Spain, advances knowledge of this theory. Their recent discoveries have been published in Physical Review Letters.
Maxwell’s theory displays a remarkable feature: it remains unaltered under the interchange of the electric and magnetic fields, when charges and currents are not present. This symmetry is called the electric-magnetic duality.
However, while electric charges exist, magnetic charges have never been observed in nature. If magnetic charges do not exist, the symmetry also cannot exist. This mystery has motivated physicists to search for magnetic charges, or magnetic monopoles. However, no one has been successful. Agullo and his colleagues may have discovered why.
Read more ~ SpaceDaily
Four Planet System in Orbit, Directly Imaged | Planetary Landscapes Credit: Many Worlds
This evocative movie of four planets more massive than Jupiter orbiting the young star HR 8799 is a composite of sorts, including images taken over seven years at the W.M. Keck observatory in Hawaii.
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Normally when a liquid is heated above its boiling point, it evaporates, turning into a vapor. But when scientists recently performed an experiment on the International Space Station (ISS), they observed that the vapor near a heat pipe condensed into a liquid even when the temperature was 160 K above the substance’s normal boiling point. The results show that microgravity significantly alters the processes of evaporation and condensation, but the scientists do not yet have a complete explanation for the phenomenon.
The research team, consisting of scientists from Rensselaer Polytechnic Institute and the NASA Glenn Research Center, have published a paper on the surprising observations in a recent issue of Physical Review Letters.
This is not the first time that unexpected behavior in heat pipes, which are devices used to cool components of a spacecraft, has been observed in microgravity. In 2015, many of the same researchers made a related, counterintuitive observation during experiments conducted on the ISS.
At that time, the researchers observed that increasing the heat input to a heat pipe did not cause the device to dry out near the heated end as it does on Earth, but instead it caused liquid accumulation there. At the time, the processes responsible for this phenomenon were not completely understood.
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La Vitrina Cloud Collection - Leandro Erlich (2011)
Versatile superstructures composed of nanoparticles have recently been prepared using various disassembly methods. However, little information is known on how the structural disassembly influences the catalytic performance of the materials. Scientia Professor Rose Amal, Vice-Chancellor’s Research Fellow Hamid Arandiyan and a group from the Particles and Catalysis Research Group from the University of New South Wales (UNSW) School of Chemical Engineering have had their research address this issue published in Nature Communications.
The research team led by Dr Jason Scott and Prof Sean Smith in collaboration with Curtin University and Beijing University of Technology has developed a method that allows them to engineer crystals with a large fraction of reactive facets. An ordered mesostructured La0.6Sr0.4MnO3 (LSMO) perovskite catalyst was disassembled using a unique fragmentation strategy, whereby the newly-exposed (001) reactive faces at each fracture were more reactive towards methane oxidation than the regular (i.e. before disassembly)
It is of significant interest to use methane as an alternative fuel to coal and oil due to its high hydrogen to carbon ratio which provides comparatively lower greenhouse gas emissions. Commercial catalysts for methane combustion contain precious metals (e.g. Pt and Pd) which are of high cost and poor thermal stability (caused by agglomeration of the metal deposits). Using perovskite-type catalysts to replace noble metal supported catalysts for methane oxidation has attracted recent attention due to their excellent thermal stability. In their recently published article, the research team describes a simple fragmentation method to synthesise a novel three-dimensional hexapod mesostructured LSMO perovskite.
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Orion
NGC 4725, One-Armed Spiral Galaxy
Geometric Animations / 170402