someone post something interesting.

How about GM organisms n food.
How do genes work anyway?
What does it mean when they say a gene "codes for a protein"?
How can you tell where a gene starts n stops in an unravelled chromosome?
Why do boffins seem to think that a gene only does one thing?

well that horse post was intresting but some one deleted it

Interesting how you used "GOD" in your topic title and then ask questions about modifying genetics......

Here's a question for you:

An electronic device generates 600 mW of internal heat, which is to be dissipated to the ambient air at 25 deg C through an aluminium heat sink with a total surface area of 12 cm2. The contact thermal resistance between the heat sink and the device is 50 K/W. The convection heat transfer coefficient between the heat sink and the air is 20 W/m2.K. The maximum permissible operating temperature of the device is 70 deg C. Show that the electronic device is destined to fail if operated under these conditions.

1st one to do it gets to sit my thermal engineering processes exam.

The answer is ..... 42


the answer to everything is 42

GlenMorangie said:

Here's a question for you:

An electronic device generates 600 mW of internal heat, which is to be dissipated to the ambient air at 25 deg C through an aluminium heat sink with a total surface area of 12 cm2. The contact thermal resistance between the heat sink and the device is 50 K/W. The convection heat transfer coefficient between the heat sink and the air is 20 W/m2.K. The maximum permissible operating temperature of the device is 70 deg C. Show that the electronic device is destined to fail if operated under these conditions.

1st one to do it gets to sit my thermal engineering processes exam.

Heat transfer sucks eh! Wait til you get onto radiation, its almost impossible to get a correct answer.

But that has me stumped too. What is that 50 K/W?

Conduction Heat transfered =Convection Heat transfered=600mW

gene technology has come so far that a pair of levis can now cost 200 bucks.

What's the similarity between a pair of Levis and a 3 bedroom house?

GlenMorangie said...

Here's a question for you:

An electronic device generates 600 mW of internal heat, which is to be dissipated to the ambient air at 25 deg C through an aluminium heat sink with a total surface area of 12 cm2. The contact thermal resistance between the heat sink and the device is 50 K/W. The convection heat transfer coefficient between the heat sink and the air is 20 W/m2.K. The maximum permissible operating temperature of the device is 70 deg C. Show that the electronic device is destined to fail if operated under these conditions.



1st one to do it gets to sit my thermal engineering processes exam.

the device was made in china .

BigFatMick said...

What's the similarity between a pair of Levis and a 3 bedroom house?

A pair as in two?

GlenMorangie said...

Here's a question for you:

An electronic device generates 600 mW of internal heat, which is to be dissipated to the ambient air at 25 deg C through an aluminium heat sink with a total surface area of 12 cm2. The contact thermal resistance between the heat sink and the device is 50 K/W. The convection heat transfer coefficient between the heat sink and the air is 20 W/m2.K. The maximum permissible operating temperature of the device is 70 deg C. Show that the electronic device is destined to fail if operated under these conditions.

1st one to do it gets to sit my thermal engineering processes exam.

You wait till you get to the control systems subjects.

At least heat transfer has some basis in non-voodoo.

ohhh noo, not that old debate again??! boring....

how about something more a bit more controversial...

like, boardies over the wetty, cool or fashion faux pas?

Victoria. good for coffee, bad for watersports. bbbrrrrrrrrrrrrrrrrrr. (get out before your testicles move inside permanently.)