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protecting the planet by fossil-fuel giant sponsor

The Shell Eco-marathon at Nogaro, France was a fine mixture of laudible ecological ambition and consumer waste, profligracy and pollution.

Shell’s aim: “The European Shell Eco-marathon is an educational project that integrates the sustainable development values with driving as far as possible using the least amount of energy.”

positive aspects:

• Low-polluting, low energy consumption vehicles, from 255 participanting teams, made test drives round the Nogaro racing circuit in southwestern France.

Last minute preparations before making test laps

• 13 types of fuel system were tested: Gasoline, Diesel, LPG, Hydrogen, Dimethyl ether, Rapeseed Oil, Methyl Ester, Ethanol, Methanol, Soya Oil, Sunflower Oil, Bio Gasoline, Electric/Solar

Fueling up with cooking oil. Note that a girl is in the driving seat.
There were many girl drivers, in order to reduce payload.

• Top (lowest) fuel usage: 2,885 km/l equivalent, using bio-fuell. This was achieved by the Lycée La Joliverie. Their car also had the lowest carbon dioxide output.

Car constructed by the Lycee La Joliverie team.
Image credit: Shell Eco-marathon

negative aspects

• Global corporation, Shell, invited teams from 20 countries around the world to ship themselves and their equipment hundreds or thousands of miles to participate.

Flags of the paricipating countries displayed by their host, Shell

• The media bussed from a local airport, and then to and fro between the race circuit and “your B&B (3 stars) in the countryside (15 kms off the motor circuit)”.
• A squadron of vehicles for the sponsors and their workers.

Shell courtesy car fleet at Nogaro, 2006

• Visitors, for the most part driving to the meeting in cars, coaches, vans, even trucks.

Public parking at the Nogaro racing circuit

All of this uses more fossil fuel, that is becoming ever more scarce, while outputting CO₂ and particulates - not very ecological.

On the road

This looks like the begining of the end for the old-type cars and internal combustion/explosion engines. There is a degree of irony watching this gathering, when all around the gathering are coaches and transporters and hundreds of cars, while the great oil companies and car manufacturers are dribbling to get their product associated with these super-efficient powered, lay-back cycles.

Many of the eco-cars are chain-driven, like the earliest motor cars

Still, it sure gets people thinking in terms of improving the product and helps train engineers in the unis.

The 2008 Nogaro Eco-Marathon takes place from 22 to 24 May.

related material
transportable fuel
fuel cells and hydrogen
ultra-lightweight car
index of shell eco-marathon 2006 press releases

the web address for the article above is
https://www.abelard.org/news/science0605.php#nogaro_300506

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take coastal intruders by surprise - stealth boats for the US military - xavier

Stiletto M-hull steath boat. Image credit: mshipco.com

“The M-hull form creates a natural surface effect that not only enhances top-speed performance, but uses the bow wave energy to reduce the overall wake signature,” said Bill Burns, co-founder of M Ship Co., noting that the military is also interested in 40- and 120-foot vessels of similar design. “This makes the boat faster and more maneuverable because it remains flat, with almost no heeling, even during high-speed turns. The vessel’s proprietary design also gives it a low-radar profile.”

some statistics

• twin M hull vessel
• length : 80 feet
• width (beam) : 40 feet
• draught when fully loaded : 3 feet
• design speed : 50 - 60 knots

The hull cross-section is shaped like the letter M, consisting of three inter-related features. These features improve ship performance —

The M-hull is a non-conventional captured air design. Image credit: mshipco.com

• the‘Central Displacement Section’ provides most of the displacement lift;
• the ‘Planing Tunnels’provide the hydrodynamic and aerodynamic lift by capturing air and the bow wave, the tunnels then gradually slope down to the water line at amidships where they run out to the transom;
• and the ‘Rigid Skirts’on the outside of the vessel that “recapture the bow wave, which then spirals through the planing tunnels. The tunnels are designed to reflect the bow wave energy and control the inboard pressure gradient under the vessel, while the outboard shape is designed to minimize pressure gradients to reduce drag and wave signature”.
  [Quoted from M-hull technology]

This all results in less turbulence, less bow and side waves, and a smaller wake. Thus, the boat is quieter and has less splashing to be visible to other sea-goers, despite it goes faster. The greater speed is helped by the small water footprint, which gives a lower water drag component.

[Lead from Limbic]

interesting things from nasa

“Under an accord between the countries' space agencies, India's first unmanned lunar mission will carry two scientific payloads from the US agency, Nasa.” [Quoted from bbc.co.uk]

pretty picture of the Earth

“This spectacular “blue marble” image is the most detailed true-color image of the entire Earth to date. Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer (.386 square mile) of our planet. These images are freely available to educators, scientists, museums, and the public. This record includes preview images and links to full resolution versions up to 21,600 pixels across.”

videos from Saturn’s moon Titan:

“ "At first, the Huygens camera just saw fog over the distant surface," said Erich Karkoschka, team member at the University of Arizona, Tucson, and creator of the movies. "The fog started to clear only at about 60 kilometers [37 miles] altitude, making it possible to resolve surface features as large as 100 meters [328 feet]," he said. "But only after landing could the probe's camera resolve little grains of sand millions and millions of times smaller than Titan. A movie is a perfect medium to show such a huge change of scale."

“For the second movie, scientists used artistic license and added sound to represent the different data sets collected. They re-created a scientifically accurate representation of the mission life in less than five minutes.”

ecological pyramid in san francisco

Transamerica Pyramid, San Francisco. Image credit: danzfamily.com

the building’s origins

“[Transamerica’s] President John R. Beckett noticed that the trees in a city park - unlike the surrounding, box-like buildings - allowed natural light and fresh air to filter down to the streets below. Wishing to achieve the same effect with Transamerica's new headquarters, an unconventional pyramid shape was chosen for the building.” [Quoted from Transamerica.com]

And how is this building becoming ecological?

“A 1.1 megawatt (MW) combined heat and power (CHP) system is being planned for the 48-story Transamerica Pyramid building in the financial district of San Francisco, California.[...]

“Northern Power's CHP system will consist of two 560 kW natural gas-fired reciprocating engine generators, which will operate in parallel with the utility's downtown network grid. The two generators are designed to provide approximately 70% of the electrical requirements of the 530,000 square foot commercial office building. Recovered waste heat from the engines will be used to heat the building, displacing 100% of the steam currently purchased for heating purposes. Additionally, waste heat will drive a 320-ton absorption chiller that will be installed to create chilled water for the building”. [Quoted from treehugger.com]

Some figures:

• Built: 1972
• Height: 853 feet plus 212-foot spire
• 48 storeys
• floor area: 530,000 square feet
  
  more detailed figures

related material
architectural items at www.abelard.org

slingshots for space exploration, war and physics experiments - the auroran sunset

NASA has asked the Army Research Labs to find way to launch things into space. One of the options is the Slingatron: a kind of glorified slingshot.

The website has various clear images and animation videos showing the workings of their various models and designs. They currently have a small mode (1m spiral) and a large model (size unspecified). The large model can apparently throw things at 300 m/sec and possibly as high as 500 m/sec. To get something into space you need to throw it at least 10 km/sec, which they say should be possible by adding a couple more turns to their large slingshot.

A classic slingshot is just a ball on a string being whizzed around as fast as possible. However, that is impractical for the speeds and weights of a ‘ball’ needed for space travel:

“Real strings undergo tensile failure [that is, they snap], and this typically limits the projectile’s maximum velocity to approximately 1km/sec, depending on the materials and design. Tensile failure of the string will occur due to the string's self-mass, even if the string is a high strength steel cable and the projectile attached at the cable end has zero mass.”

The Slingatron works in a very different way:

“The acceleration process is similar to rolling a ball bearing around in a frying pan in a horizontal plane and gyrating the pan around a small circle in order to accelerate the ball bearing to high speed”

Image credit: Slingatron

The Slingatron is a hollow, spiral-shaped tube sat on a platform that can be moved around like a theme park flight simulator ride. The ball is put in the middle of the spiral at the start of the tube and anchored there. Then the platform is spun around in a ‘circle’ until it reaches full speed, at which point the ball is released. The ball then starts moving along the spiral, speeding up to approximately eleven times its release speed when it comes out the exit, assuming a three-loop spiral. The first PDF below gives, what I must assume, is a reasonable example of a 10kg ‘ball’ with the platform going round 60 times per second, or at a speed of 150m/s. The PDF is not entirely clear, but I think it is claiming that with a ball that size and with the Slingatron going at that speed, only 43MW of power is needed.

Image credit: Slingatron

The g-forces involved would be far too high for people, but this sort of system could be very useful for sending hardware up:

“an orbital launcher would bring the cost of putting a payload into orbit from around $10,000 a pound to a few hundred dollars.”

And unlike rockets, it is fully reusable.

The Slingatron website has excellent educational pages with clear diagrams explaining about different kinds of slingshots and the physics and engineering behind them: acceleration concepts, spiral layouts, swing arm designs, feed systems, large length-over-diameter projectiles and scaling of mechanics.

For further study, they have a fascinating 20-page PDF explaining in mathematical detail the physics behind the Slingatron and other slingshots.

For those who want more fun, there is another 7-page PDF on Constant-Frequency Hypervelocity Slings.

The Slingatron website refers to possible uses in physics experiments requiring high-energy collisions. Defense Tech suggests myriad possible military uses:

“Or it could be used to put up new nano-satellites by the score, at short notice and without the need for scarce and expensive rockets.

“But for the Pentagon it could be a candidate for the ideal Global Strike tool: capable delivering a one-ton bunker-busting tungsten supercavitating penetrator at orbital speed. [Not that we're encouraging this sort of thing.] That’s real Shock & Awe, which could arrive anywhere in the world with no warning before bombers could get off the runway. (Anyone remember Saddam Hussein’s Project Babylon Supergun , or the Nazi’s V3 plans?)

“Alternatively, an aeroballistic pod could be launched which would break open at high altitude to release a dozen Dominators or similar craft to find and attack precision targets, catching fleeing terrorists in less time than it takes to get a Predator into the area.

“Then again, the anti-satellite people might want to have a go too. [Not that we're looking to encourage them, either.] It would make a neat anti-aircraft gun, firing small guided projectiles, and might offer some interesting options for kinetic ballistic missile defense.

“Maybe SOCOM might want a look for about instant re-supply anywhere, for when it absolutely, positively has to be there within the hour, regardless of weather conditions?”

A science note:

There is no such thing as a “centrifugal force” - a force that throws a rotating object outwards - it is a misuse of language born of a commonly-held misunderstanding.

When you swing a ball round on a string, the only force is one that acts in the opposite fashion: pulling the ball towards the centre of the circle - your hand! This force is called the “centripetal force”.

It is this centripetal force that stops the ball from continuing in a straight line - as Newton says it must when no force acts - making it constantly change direction round the circle.

When you let go of your slingshot - ie stop applying the centripetal force - the object flies off in a straight line in the direction it was going when you let go, because there is now no force stopping it (well apart from air resistance and gravity!). This is why when swinging that ball around your head, you pull on the bit of string, rather than push!

The same applies with satellites: gravity is constantly pulling them towards the centre of the Earth, stopping them flying onwards in a straight line as they would be otherwise inclined to do.

“tallest residential building in europe”

Name: Turning Torso Tower Location: Malmö, Sweden Height: 190 metres Opened: August 2005 Cost: 125 million € Motion-activated lighting with Golden Dragon LEDs, Osram and custom-made fixture, Louis Poulsen Lighting       related material architectural items at www.abelard.org

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