91Èȱ¬

On Tech Brief today; why the writing's on the wall for e-readers, carbon nanotubes give batteries a boost, and how to "de-vuvuzela" the World Cup.

• The honeymoon is well and truly over for the e-reader market, .

There's a new kid on the block in the form of the iPad, and retailers Amazon and Barnes & Noble have both slashed the prices of their e-reader devices (but not the actual books) since its arrival.

"The 'give away the razors and sell the blades' model doesn't work with dedicated e-book readers because Amazon and Barnes & Noble's customer base is increasingly becoming iPad and iPhone users, and shortly will also be Android phone and tablet users."

The fierce undercutting means that devices marketed by smaller rivals such as Plastic Logic and Kobo will "almost certainly be gone within the next few months" Mr Perlow warns.

• The clever folk at have found a way of making batteries last 10 times longer by using carbon nanotubes as positive electrodes, :

"The prototype batteries possess the positive characteristics of both capacitors in their ability to deliver very short high bursts of energy and still have the energy content of state-of-the-art lithium-ion batteries, around 200 Watt hours per kilogram. This combination makes them attractive for Electric Vehicles (EV) technology that requires quick bursts of power for acceleration."

The research has been published today in [subscription required].

• It's coalition time again - O2, Orange and Vodafone have teamed up to trial IMB (Integrated Mobile Broadcasts) in London and Slough, UK. IMB is a more efficient (which of course means cheaper) way of streaming TV and video using existing 3G networks, :

"It is increasingly becoming apparent to operators that it is more practical to use their own 3G networks than it is to build more expensive DVB-H broadcast networks. News of the IMB trial by the international operators makes it even less likely that DVB-H will ever achieve widespread deployment."

• For any football spectators who might be irritated by the World Cup vuvuzelas, this will be music to their ears.

. It dampens the noise of the incessant horns to make the commentary more audible.

The researchers analysed the various sounds from a live match and noted:

"The commentator, then, is the loudest thing here... Somewhat lower in level are the nearly-flat horizontal tracks of the massed chorus of vuvuzelas. It appears that although these instruments vary, most of them are clumped in a fairly small range of fundamental frequencies - around 230Hz, roughly the B-flat below middle C. This unvarying pitch suggests why some listeners may find them so troublesome."

Best of all, the devuvuzelator is free to download.

• Finally, a bit of an oldie but it's too good to miss. The coach of the North Korea football team has told sports broadcaster that he has been receiving training tips from the country's leader Kim Jong-il via an invisible phone. :

"Jong-il, a man of many talents, is said to have developed the technology himself. Before you laugh in disbelief, remember this is the man who scored 38 under par in his first-ever game of golf -- with five holes in one -- making him the greatest golfer of all-time. No word yet whether North Korea also has an invisible vuvuzela in the works."

If you want to suggest links or stories for Tech Brief, you can send them to on , tag them bbctechbrief on or e-mail them to techbrief@bbc.co.uk.

Links in full

•
•
•
•
•