Blog Posts

terça-feira, 6 de setembro de 2011


Um Motor eléctrico do tamanho... DUMA MOLÉCULA!

Electric motor made from a single molecule 
Researchers have created the smallest electric motor ever devised. The motor, made from a single molecule just a billionth of a metre across, is reported in Nature Nanotechnology. The minuscule motor could have applications in both nanotechnology and in medicine, where tiny amounts of work can be put to efficient use. Tiny rotors based on single molecules have been shown before, but this is the first that can be individually driven by an electric current. "People have found before that they can make motors driven by light or by chemical reactions, but the issue there is that you're driving billions of them at a time - every single motor in your beaker," said Charles Sykes, a chemist at Tufts University in Massachusetts, US. "The exciting thing about the electrical one is that we can excite and watch the motion of just one, and we can see how that thing's behaving in real time," he told BBC News. 

Uma Célula de Combustível a Propano quadruplica o alcance dum Avião Não Tripulado, e o que não fará ela por Ultra-Leves?

Flight time of Stalker small UAS quadrupled with ruggedized propane fuel cell
By Darren Quick

Small unmanned aircraft systems (UAS) have become an increasingly important intelligence, surveillance and reconnaissance tool for the military and their use will only continue to expand. While vehicles that are small enough to be carried provide soldiers in the field with capabilities such as over-the-next-hill imagery or the short-term monitoring of convoys, much research is going into finding ways to extend mission duration through better battery systems. DARPA researchers say they have overcome this limitation with the development of a compact solid oxide fuel cell (SOFC) fueled by propane that quadruples the endurance of Lockheed Martin's Stalker small UAS.

The new fuel cell formed the basis of the hybrid power source for the Stalker XE, (eXtreme Endurance), a variant of the Lockheed Martin-developed Stalker UAS that boasts a wingspan of 120-in (305 cm) and is powered solely by a battery-driven electric motor that gives it a flight time of around two hours. By combining a high density fuel cell system with a conventional lithium polymer battery to handle peak power requirements, the Stalker XE is able to quadruple the endurance of the baseline Stalker version to provide a flight time of over eight hours.

E algo para os Ciclistas:

Hase Bikes' KLIMAX tricycle converts into a velomobile

By Ben Coxworth

While there are those of us who are strangely attracted to velomobiles - recumbent tricycles with full aerodynamic fairings - the idiosyncratic vehicles certainly have their drawbacks. Among these are the fact that the fairing, which is usually a hard shell, adds weight and traps heat inside with the rider. It also contributes to the sky-high price of the trikes, which can reach around US$15,000. Hase Bikes has taken an interesting approach with its KLIMAX 2K recumbent tricycle by using a weatherproof fabric fairing, that folds down and comes off when not wanted.

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