The club wanted real grass rather than an artificial pitch, plus a
comfortable stadium complete with a sliding roof for all-weather use. The two
requirements are hard to meet at the same time, as rival team Ajax recently
discovered. Amsterdam-based Ajax’s new umbrella-roof stadium has a fixed pitch,
but limited natural light and rain has led to yellow, faded grass and high
maintenance costs.

In Vitesse’s stadium, the entire pitch is set into a concrete plate mounted
on Teflon feet. When the pitch is not in use, a set of four hydraulic rams moves
the whole 11 000-tonne assembly out from the centre of the 28 000-seater
stadium, under the south stand and into the open. As well as being good for the
pitch, this arrangement will make it easier to use the stadium for other events,
such as concerts.

The ÂŁ40 million project opens in March. A quarter of the money was
provided by banks, but the majority came from government.

With ever more crowded skies, there is an increasing need for pilots to go
through simulated emergencies such as near misses. But according to the Delft
team, earlier simulators were too sluggish to be realistic.

“There is little feeling of what an aircraft does,” says Herold Cremer, an
aeronautical engineer on the project. “A pilot in training must be able to
experience the `flying by the seat of your pants’ feeling.”

The new simulator, called Simona, sits on six computer-controlled hydraulic
legs that have a response time of just 20 milliseconds. The lightweight
structure is built from polymer reinforced with carbon fibre, and is almost
perfectly balanced so that it can withstand oscillations of up to 12 hertz. This
means it should be able to simulate even the most difficult circumstances, such
as landing a helicopter on a rocking oil rig platform.

Simona incorporates a “tunnel in the sky” 3D simulator package called
Delphin, which gives pilots a 360° view. Trainees must steer their way
through a twisting tunnel towards the landing site, while their every response
is monitored and accounted for automatically by a central computer.

Simona is the result of a five-year, ÂŁ7.5-million research programme,
sponsored by Boeing and Cessna, Caledonia University in Glasgow, the National
Aerospace Agency of Japan and the Dutch government.

Simona’s cabin can also be retrofitted to simulate other vehicles, such as
high-speed trains or ships.

Researchers at the department of seismics and acoustics at Delft
University of Technology in the Netherlands have found a way to move the source
of sound around, so that every listener in a concert hall hears the performance
as if it were being staged just in front of them. They used hundreds of
microphones and speakers, linked by computer software that shifts the frequency
of the sound waves to compensate for distance, echo and distortion.

A. J. Berkhout and colleagues have built a small test chamber
equipped with 160 microspeakers positioned in a thin band around its four walls.
By shifting a sound source around the speaker array, Berkhout can compensate
for distortion in badly made conference halls.

Berkhout is already preparing to install a multispeaker system in
the Doelen concert hall in Rotterdam and the Opera House at Malmö in
Sweden.

The technique could also make video conferences seem like face-to-face
meetings. Berkhout will create rooms in France Telecom’s buildings that will
have half a conference table pushed against a large high-definition TV screen.
Real-time, full-size images of video participants will be shown on the screen.
Their voices will emanate from where they are sitting.

Starting this autumn, Deutsche Post will begin replacing its 15 000 diesel and petrol-driven postal vans with vehicles that use zinc-air batteries. Developed by an Israeli company called Electric Fuel, the batteries create no emissions and are recyclable and easy to refuel.

Deutsche Post is making the switch after exhaustive field tests on dozens of its chosen models: GM-Opel Corsa Combo vans and Mercedes-Benz 4-tonne MB410 medium-range delivery vehicles, all fitted with the zinc-air batteries. (Technology, 22 January 1994, p 20).

A typical test demanded a Mercedes MB410 van carry a normal load 425 kilometres between Bremen and Bonn without refuelling. Not only did the vehicles complete the five-hour journey over hilly terrain and through congested traffic without needing to refuel, they even reached a top speed of 120 kph.

The venture between the postal service and Electric Fuel was unveiled last week at the World Sustainable Energy Trade Fair in Amsterdam. Deutsche Telekom—the German telephone service—and several local councils are also considering adopting electric vehicles, now that Deutsche Post is making the switch.

A typical postal van will be fitted with two 12-block fuel trays containing 22 individual zinc-anode cassettes with a total energy content of 180 watt-hours per kilogram—a big improvement on the 30 watt-hours per kilogram that a lead-acid battery typically produces.

The zinc-air battery produces power as its zinc anodes are oxidised. Its operating temperature is 70 °C but a test drive of a van across the Alps proved it can work in temperatures as low as –20 °C. Refuelling the battery, which involves swapping fresh cassettes for exhausted ones, takes seven minutes.

A spokesman for Deutsche Post says it is adopting zinc-air vehicles because they are safe and clean, and there is no danger from toxic emissions to drivers and maintenance personnel.

Another advantage of the zinc-air system, he says, is the range of the refuelled vehicle. A typical weekly round for a Deutsche Post van is 350 kilometres. The zinc-air battery allows them to travel this far on one set of cassettes.

The zinc plates from used cassettes will be crushed and reformulated for reuse. Deutsche Post is currently considering whether to build a single reprocessing plant for the whole fleet or a number of regional ones before starting to replace vehicles this autumn.