Group items tagged

As I mentioned it into my thesis, this engine bridges the gap between chemical and low-thrust propulsion systems. To be more specific: Isp should vary between 1000 and 30000s, and the thrust amplitude should reach up to 1200 N. It is interesting to see that the concept is actually moving forward ...

Recharge in seconds and efficiently store power for weeks between charges. Added bonus is the cheap and abundant components needed. One of the applications they foresee is to attach such a super-capacitor to the back of solar panels to store the power and discharge this during the night

very nice indeed - is this already at a stage where we should have a closer look at it? what you think? With experience in growing carbon nanostructures, Pint's group decided to try to coat the porous silicon surface with carbon. "We had no idea what would happen," said Pint. "Typically, researchers grow graphene from silicon-carbide materials at temperatures in excess of 1400 degrees Celsius. But at lower temperatures - 600 to 700 degrees Celsius - we certainly didn't expect graphene-like material growth." When the researchers pulled the porous silicon out of the furnace, they found that it had turned from orange to purple or black. When they inspected it under a powerful scanning electron microscope they found that it looked nearly identical to the original material but it was coated by a layer of graphene a few nanometers thick. When the researchers tested the coated material they found that it had chemically stabilized the silicon surface. When they used it to make supercapacitors, they found that the graphene coating improved energy densities by over two orders of magnitude compared to those made from uncoated porous silicon and significantly better than commercial supercapacitors. Transmission electron microscope image of the surface of porous silicon coated with graphene. The coating consists of a thin layer of 5-10 layers of graphene which filled pores with diameters less than 2-3 nanometers and so did not alter the nanoscale architecture of the underlying silicon. (Cary Pint / Vanderbilt) The graphene layer acts as an atomically thin protective coating. Pint and his group argue that this approach isn't limited to graphene. "The ability to engineer surfaces with atomically thin layers of materials combined with the control achieved in designing porous materials opens opportunities for a number of different applications beyond energy storage," he said.

apparently competitive with CNT and others in performance, while as you would expect very cheap. anyone know what happens to chicken feathers in a vacuum?

" The goal of the APT program is to control and direct plant physiology to detect chemical, biological, radiological, and/or nuclear threats, as well as electromagnetic signals. " Now that is an advanced concept...

and look at this exceptional insight: "plants are easily deployed, self-powering, and ubiquitous in the environment, and the combination of these native abilities with specifically engineered sense-and-report traits will produce sensors occupying new and unique operational spaces" :-)