Group items tagged

"Switchable nanomaterials-materials that can change their properties and/or function in response to external stimuli-have potential applications in electronics,..."

interestingly it looks like a subject could wear it all day while doing normal stuff http://www.choosemuse.com/ "I got my hands on an early version of Interaxon's brainwave reading headband, the Muse, and I think this could be the most important wearable of the year. And that's saying a lot, considering I've seen 2014′s entire lineup for health tech at the Consumer Electronic Show as well as a few undisclosed athletic devices slated for later this year."

..."alerts the users with sights and sounds when they are producing brain waves associated with calm and focus." ALERT! ALERT! ALERT! YOU ARE CALM AND FOCUSSED! :-D

indeed the app that comes with it sounds really lame but it comes with an sdk

A new method of separating nuclear isotopes that exploits the slight differences in their electronic energy levels has been developed by physicists in the US. The energy-efficient separator was used to create isotopically pure lithium-7, which is used in some nuclear reactors. Good news for any future nuclear powered space missions perhaps? It could potentially replace the current (and much less energy efficient) methods that were developed in the 1950's

Unlike any other living thing on Earth, electric bacteria use energy in its purest form - naked electricity in the shape of electrons harvested from rocks and metals. We already knew about two types, Shewanella and Geobacter. Now, biologists are showing that they can entice many more out of rocks and marine mud by tempting them with a bit of electrical juice. Experiments growing bacteria on battery electrodes demonstrate that these novel, mind-boggling forms of life are essentially eating and excreting electricity.

Two apps - the Distributed Electronic Cosmic-ray Observatory (DECO) and Cosmic Rays Found in Smartphones (CRAYFIS) - transform smartphones into miniature cosmic-ray detectors. They use the CMOS chips inside phones' onboard cameras to detect the secondary particles produced when cosmic rays - energetic, charged subatomic particles arriving from beyond the solar system - collide with air molecules in the Earth's atmosphere

The first complete theory of how plasmons produce "hot carriers" has been developed by researchers in the US. The new model could help make this process of producing carriers more efficient, which would be good news for enhancing solar-energy conversion in photovoltaic devices.

I did not read the paper but what is further down written in the article, does not give much hope that this actually gives much more insight than what we had nor that it could be used in any way to improve current PV cells soon: e.g. "To fully exploit these carriers for such applications, researchers need to understand the physical processes behind plasmon-induced hot-carrier generation. Nordlander's team has now developed a simple model that describes how plasmons produce hot carriers in spherical silver nanoparticles and nanoshells. The model describes the conduction electrons in the metal as free particles and then analyses how plasmons excite hot carriers using Fermi's golden rule - a way to calculate how a quantum system transitions from one state into another following a perturbation. The model allows the researchers to calculate how many hot carriers are produced as a function of the light frequency used to excite the metal, as well as the rate at which they are produced. The spectral profile obtained is, to all intents and purposes, the "plasmonic spectrum" of the material. Particle size and hot-carrier lifetimes "Our analyses reveal that particle size and hot-carrier lifetimes are central for determining both the production rate and the energies of the hot carriers," says Nordlander. "Larger particles and shorter lifetimes produce more carriers with lower energies and smaller particles produce fewer carriers, but with higher energies."

An exhaustive overview of all possible advanced rocket concepts, eg.. "As an example, consider a photon rocket with its launching mass, say, 1000 ton moving with a constant acceleration a =0.1 g=0.98 m/s2. The flux of photons with E γ=0.5 MeV needed to produce this acceleration is ~1027/s, which corresponds to the efflux power of 1014 W and the rate of annihilation events N'a~5×1026 s−1 [47]. This annihilation rate in ambiplasma l -l ann corresponds to the value of current ~108 A and linear density N ~2×1018 m−1 thus any hope for non-relativistic relative velocity of electrons and positrons in ambiplasma is groundless." And also, even if it would work, then one of the major issues is going to be heat dispersal: "For example, if the temperature of radiator is chosen T=1500 K, the emitting area should be not less than 1000 m2 for Pb=1 GW, not less than 1 km2 for Pb=1 TW, and ~100 km2 for Pb=100 TW, assuming ε=0.5 and δ=0.2. Lower temperature would require even larger radiator area to maintain the outer temperature of the engine section stable for a given thermal power of the reactor."

The problem is not achieving a high energy density, that we can already do with nuclear fission, the question however is how to confine or harness this power with relatively high efficiency, low waste heat and at not too crazy specific mass. I see magnetic confinement as a possibility, yet still decades away and also an all-or-nothing method as we cannot easily scale this up from a test experiment to a full-scale system. It might be possible to extract power from such a plasma, but definitely well below breakeven so an additional power supply is needed. The fission fragments circumvent these issues by a more brute force approach, thereby wasting a lot of energy for sure but at the end probably providing more ISP and thrust.

Sure. However, the annihilation based photon rocket concept unifies almost all relevant drawbacks if we speak about solar system scales, making itself obsolete...it is just an academic testcase.

The effect of gravity on virtual electron-positron pairs as they propagate through space could lead to a violation of Einstein's equivalence principle, according to calculations by James Franson at the University of Maryland. While the effect would be too tiny to be measured directly using current experimental techniques, it could explain a puzzling anomaly observed during the famous SN1987 supernova of 1987.

Guinness World Record breaking, "first radio amplifier operating at terahertz frequencies could lead to communications systems with much higher data rates, better radar, high-resolution imaging that could penetrate smoke and fog, and better ways of identifying dangerous substances, say the researchers who built it". Built from HEMTs (High Electron Mobility Transistors) made of InP (Indium Phosphide), this is a new milestone on the road to the THz applications.

First peer review study about he criticality of rare-earth metals. It can be read "They found that supply limits for many metals critical in the emerging electronics sector (including gallium and selenium) are the result of supply risks. The environmental implications of mining and processing present the greatest challenges with platinum-group metals, gold, and mercury. For steel alloying elements (including chromium and niobium) and elements used in high-temperature alloys (tungsten and molybdenum), the greatest vulnerabilities are associated with supply restrictions" Questions about estimation apart, this can be a valuable market for asteroid mining.. (ot just more market for Infinium-like companies http://www.technologyreview.com/news/527526/a-cleaner-cheaper-way-to-make-metals/).

So basically we can photograph light now. Not just detect photons but photograph LIGHT WAVES. Really clever setup BTW.

new darpa project ... who still remembers our Ariadna study from 2005 ....?

seems also potentially useful for astronauts ...

Researchers from North Carolina State University have discovered a new phase of solid carbon, called Q-carbon, which is distinct from the known phases of graphite and diamond. They have also developed a technique for using Q-carbon to make diamond-related structures at room temperature and at ambient atmospheric pressure in air. It turns out this configuration is harder than diamond, plus the material has a very low work function. The latter might be very interesting for electronics or as electrode material.

Maybe* this is the wonder material with very low workfunction needed in the Photon Enhanced Thermionic Emitter future prototype :)

Quoted from one of the authors in a separate interview: "We know that the spin states of atomic nuclei associated with semiconductor defects have excellent quantum properties at room temperature," said Awschalom, Liew Family Professor in Molecular Engineering and a senior scientist at Argonne National Laboratory. "They are coherent, long-lived and controllable with photonics and electronics. Given these quantum 'pieces,' creating entangled quantum states seemed like an attainable goal." Bringing the quantum world to the macroscopic scale could see some interesting applications in sensors, or generally entanglement-enhanced applications.

They were previously working on the same concept in N-V centers in diamond (as a semiconductor). Here the advantage is that SiC could in principle be integrated with Si or Ge. Anyway its all about controlling coherence. In the next 10 years some breakthroughs are expected in the field of semiconductor spintronics, but quantum computing in this way lies still in the horizon

Cool hologram generating tabletop. Check the videos. Would be interesting if it could be scaled down..

An experiment at the Fermi National Accelerator Laboratory near Chicago has detected far more electron neutrinos than predicted - a possible harbinger of a revolutionary new elementary particle called the sterile neutrino, though many physicists remain skeptical.

Brings back some memories... Enjoy!

indeed, I still have the bottle! don#t dare drinking it