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Mostrar mensagens com a etiqueta poplular science. Mostrar todas as mensagens
Mostrar mensagens com a etiqueta poplular science. Mostrar todas as mensagens

quinta-feira, 21 de julho de 2011

MUITO importante para os Países Africanos!

Isto é que é uma boa ideia, para limpar Àfrica dos campos de minas:

Video: Minesweeping Tank-Bot Shreds Land Mines, Rolling Through Explosions With Ease
Digger D-3 laughs in the face of unexploded ordnance
By Rebecca Boyle
Technology is helping de-miners find unexploded land mines in new and cool ways, like the metal detectors augmented with smartphones we learned about this spring. And now, there are mine-chomping tank robots that eat mines for breakfast.

The Digger D-3 is the latest creation of Digger DTR, a Swiss non-governmental organization dedicated to designing mine-clearing devices. It has a spinning tiller of death called a flail, made of tungsten hammers that pound 10 inches into the ground. It also has a rolling tiller that can clear vegetation. The remote-controlled tank was brought to light by IEEE Spectrum’s robotics blog.

The D-3 is fully armored to withstand land mines and ordnance up to 81mm in diameter, Digger says. It has a four-cylinder, 4.5 L John Deere diesel engine, which can crank out 173 hp at 2400 RPM. The remote-controlled robot is as adept at clearing shrubbery as it is at chomping mines, so it’s ideal for minefields with dense vegetation or in mountainous areas, Digger says.

The video below shows its predecessor, the D-2, surviving mine explosions in Sudan. The new model is designed to be easily repaired and modified, enabling it to be used in remote locations with limited resources and plenty of land mines.


http://www.popsci.com/technology/article/2011-07/easily-repaired-minesweeping-tank-bot-shreds-land-mines


...E eis ondas nunca vistas:


Scientists Discover Two Never-Before-Seen Kinds of Water Waves
By Clay Dillow

Of all the things in the physical world we think we know a lot about, water is definitely among them. Nonetheless, by precisely shaking a shallow container of water, researchers have now observed two new types of waves that have never been observed before in water--and one that has never been observed in any other media either.

To conjure the waves, the researchers used what is known as a Hele-Shaw cell mounted on a small shake table. A Hele-Shaw cells is a container consisting of two parallel transparent plates separated by a small gap, much like an ant farm (see images above and .gifs below). In this case, the gap between them was 1.5 millimeters, or less than 6 hundredths of an inch.





...Mais uma para os que pensam que os Cientistas "já sabem tudo", o calor do interior da Terra, só 50% é que se sabe a origem!




The Best Measurement Yet of Earth's Radioactivity Shows Half the Earth's Heat Comes from Nuclear Decay
By Clay Dillow
Scientists measuring the subatomic particles flowing from Earth’s interior have taken the most precise measurement ever gathered of the home planet’s radioactivity. It turns out nearly half of the Earth’s total heat output comes form decaying radioactive elements like thorium and uranium in the Earth’s crust. But that’s an answer that begets more questions.

Previously, there were varying theories on just how much of the Earth’s heat came from radioactive decay, with many--accurately, it would seem--placing that value at about half of the roughly 40 terawatts of heat produced by the Earth. That heat drives convection currents in the outer core and give us our magnetic field, among other natural processes (tectonics come to mind).

http://www.popsci.com/science/article/2011-07/best-measurement-yet-earths-radioactivity-shows-half-earths-heat-comes-decay

sábado, 6 de março de 2010

3 Boas Notícias!

Mais perto da fusão:

Thursday, January 28, 2010
Scientists Overcome Obstacle to Fusion
The world's largest laser system has uniformly compressed and superheated a fuel capsule.
By Kevin Bullis
One of the key outstanding questions about whether it's possible to use lasers to ignite fusion has been answered. A huge, stadium-sized laser facility at the Lawrence Livermore National Laboratory in Livermore, CA, uniformly compressed and heated a tiny capsule to very high temperatures. The experiments confirmed a theory the scientists there had about how to control the energy from 192 high-power lasers to compress the spherical capsule evenly from all sides.
http://www.technologyreview.com/blog/energy/24720/


Um novo Bio-Combustível de Alta Densidade:


New Process Yields High-Energy-Density, Plant-Based Transportation Fuel
by Staff Writers
Madison WI (SPX) Mar 01, 2010
A team of University of Wisconsin-Madison engineers has developed a highly efficient, environmentally friendly process that selectively converts gamma-valerolactone, a biomass derivative, into the chemical equivalent of jet fuel.


While biofuels such as ethanol are becoming more popular as blending agents in automobile fuels, they have limitations for use in jet fuel because of their low energy density. And, given present internal combustion engine designs, conventional biofuels cannot fully replace petroleum-derived hydrocarbons.
http://www.biofueldaily.com/reports/New_Process_Yields_High_Energy_Density_Plant_Based_Transportation_Fuel_999.html


Uma autêntica maravilha, TODOS os Ficheiros da revista Popular Science, à mão de semear:

We've partnered with Google to offer our entire 137-year archive for free browsing. Each issue appears just as it did at its original time of publication, complete with period advertisements. It's an amazing resource that beautifully encapsulates our ongoing fascination with the future, and science and technology's incredible potential to improve our lives. We hope you enjoy it as much as we do.

In the future, we'll be adding more advanced features for searching and browsing, but for now, enter any keyword into the box below and dive in.


http://www.popsci.com/archives


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