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he new SR-72 will use a turbine-based combined cycle (TBCC) that will employ the turbine engine at lower speeds, and use a scramjet at higher speeds. A scramjet engine is designed to operate at hypersonic velocities by compressing the air through a carefully designed inlet, but needs to be traveling supersonic before it is practical to begin with. So far research projects from NASA, the Air Force and other Pentagon entities have not been able to solve the problem of transitioning from the subsonic flight regime, through hypersonic flight with a single aircraft. Same problem as Reaction Engines is trying to solve, so I am not sure whether they actually cracked it. In any case, nice pictures. Not sure why the exhaust color is purple in color. Its not running on Argon I believe.

Weird article. Intermediate thruster stage (Ramjet) is missing. Scramjet has supersonic combustion and a normal turbine delivers subsonic flows. Even with afterburner - the Scramjet inlet would decelerate the flow down to subsonic velocity with "normal" subsonic combustion. The only thing I can imagine is that the Scramjet stage is bi-functional and covers both, subsonic and supersonic combustion. But the article doesn't say anything about it.

There you go, the latest-and-greatest chip is there. Now the only remaining tiny detail - program it.

Let's buy it first and we'll figure the rest out later :P

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."

Several new components for biological circuits have been developed by researchers. These components are key building blocks for constructing precisely functioning and programmable bio-computers. "The ability to combine biological components at will in a modular, plug-and-play fashion means that we now approach the stage when the concept of programming as we know it from software engineering can be applied to biological computers.

The functional principle is similar to ordinary pumped storage plants: when power is needed, water flows into the sphere and drives the turbine thus generating power. If surplus power is available (usually during the night), water can be pumped out of the sphere again, thus effectively charging the storage system.

very nice! "For a start, the wires operate well as switches that by some measures compare well to field effect transistors. For example they allow a million times more current to flow when they are on compared with off when operating at a voltage of about 1.5 V. "[A light effect transistor] can replicate the basic switching function of the modern field effect transistor with competitive (and potentially improved) characteristics," say Marmon and co. But they wires also have entirely new capabilities. The device works as an optical amplifier and can also perform basic logic operations by using two or more laser beams rather than one. That's something a single field effect transistor cannot do."

any idea how the shine the light selectively to such small surfaces?

"Illumination sources consisted of halogen light, 532.016, 441.6, and 325 nm lasers ported through a Horiba LabRAM HR800 confocal Raman system with an internal 632.8 nm laser. Due to limited probe spacing for electrical measurements, all illumination sources were focused through a 50x long working distance (LWD) objective lens (N.A. = 0.50), except 325 nm, which went through a 10x MPLAN objective lens (N.A. = 0.25)." Laser spot size calculated from optical diffraction formula 1.22*lambda/NA

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 :)

Really nice visualizations for rectifier (ReLU) neural nets, illustrating the effects of skip-connections, depth, width, etc. on the loss function curvature.

Loss of connectivity in the multisensory integration cortical areas after short term microgravity experience, which could explain astronauts decrease of performance in sensorimotor tasks and spatial working memory. However, the effect should wear off after a few days in microgravity and after adaptation to incongruent vestibular information. ISS experiment needed...