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exotic ceramic could halve microwave cooking bills

updated mon 21 jul 08

 

Edouard Bastarache on wed 16 jul 08


Exotic ceramic could halve microwave cooking bills
Baking dishes made from an exotic ceramic material could speed up the =
rate at which microwave ovens cook food, reducing the energy needed for =
cooking.

Microwave ovens use a neat trick to rapidly heat food. Microwaves have =
an alternating electric component that causes any molecules with a =
positive charge at one end and a negative charge at the other, such as =
water, to rotate and align themselves with the field.

The rotating water molecules jostle other nearby molecules, which also =
begin to move. Simply because these molecules are in motion, the food =
becomes hot.

But microwave ovenware is "transparent" to microwaves and so only heats =
up by conduction as it touches the hot food.

That means that the food loses some heat to its container. Ovenware that =
is directly heated by microwaves could reverse that loss by conductively =
heating the food instead, which would improve the efficiency of =
microwave cooking.

Baking dish baked
Now, Sridhar Komarneni at Pennsylvania State University, together with =
Hiroaki Katsuki and Nobuaki Kamochi at the Saga Ceramic Research =
Laboratory in Saga, Japan, have developed a new ceramic with =
microwave-absorbing properties.

Komarneni's team took powdered petalite, a lithium-rich mineral, and =
mixed it with a small quantity of magnetic iron oxide. They dried the =
powder and fired it in a kiln for 5 hours, before sintering it at =
1250=B0C to create an iron oxide-petalite foam suitable for use as a =
microwave ceramic.

The iron oxide component interacts with the microwaves' electric field =
and rapidly heats, while the insulating petalite component helps to =
retain that heat after the oven is switched off.

Porcelain is so slow
The researchers tested their new foam against standard porcelain =
ovenware in a 600-watt microwave oven. After 70 seconds of power, the =
porcelain had reached 50-60=B0C, but the new foam had risen to over =
200=B0C.

The foam continued to gain temperature for another 30 seconds after the =
power was switched off, peaking at 294=B0C. That's because it takes a =
few seconds for the heat to spread from the iron oxide component =
throughout the foam, says Komarneni.

"The microwave-ware saves about 50% energy compared to the conventional =
microwave ware," says Komarneni. A ceramic rice cooker constructed using =
the new foam takes just 10 minutes to prepare rice instead of 20-30 =
minutes using conventional ovenware.

And it may not be long before you can buy the new ovenware. The new =
material is already being commercialised by a company in Japan, says =
Komarneni.

Journal reference: Chemistry of Materials, DOI: 10.1021/cm801138n



Gis la revido

Edouard Bastarache
Spertesperantisto

Sorel-Tracy
Quebec
Canada

http://www.flickr.com/photos/30058682@N00/
http://pagesperso-orange.fr/smart2000/livres.htm
http://www.flickr.com/photos/potier/20321056/
http://myblogsmesblogs.blogspot.com/

Lee Love on wed 16 jul 08


On Wed, Jul 16, 2008 at 3:31 PM, Edouard Bastarache
wrote:
> A ceramic rice cooker constructed using the new foam takes just 10 minutes to
>prepare rice instead of 20-30 minutes using conventional ovenware.

Haha! Just what we need! Faster food! Next are inventions to make
us eat fast. Have sex fast.

Sometimes slow is good. That is why I don't buy Steve and Ron's
attitude about pottery. Sometimes the old way is better. Especially
in our frantic post-modern lives.

--
Lee Love in Minneapolis
http://mashikopots.blogspot.com/
http://claycraft.blogspot.com/

"Let the beauty we love be what we do.
There are hundreds of ways to kneel and kiss the ground." --Rumi

Ron Roy on sun 20 jul 08


On the other hand, using less energy is a good idea - and the longer you
cook food the more nutrition is lost.

Nothing wrong with evaluating new ideas to see if there are advantages.

The time saved can be used for slower eating and slower sex.

I don't see the connection between pottery however - do we advocate faster
pottery - and what does that mean?

RR

>On Wed, Jul 16, 2008 at 3:31 PM, Edouard Bastarache
> wrote:
>> A ceramic rice cooker constructed using the new foam takes just 10 minutes to
>>prepare rice instead of 20-30 minutes using conventional ovenware.
>
> Haha! Just what we need! Faster food! Next are inventions to make
>us eat fast. Have sex fast.
>
> Sometimes slow is good. That is why I don't buy Steve and Ron's
>attitude about pottery. Sometimes the old way is better. Especially
>in our frantic post-modern lives.
>
>--
> Lee Love in Minneapolis
>http://mashikopots.blogspot.com/
>http://claycraft.blogspot.com/
>
>"Let the beauty we love be what we do.
>There are hundreds of ways to kneel and kiss the ground." --Rumi

Ron Roy
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0