Attention 2easy2Bpoor, Fonzie, and all you other haters. Come here to get educated.

[Lumberg]

I've heard of people growing ears on the backs of mice? Have you seen this?

Yeah, I'd like to get like a number or something of these clinics... perhaps send it along to Jaqui... maybe she has not explored this idea yet.

C-ditty

yeah i have heard of that too but as far as i know it was just an experiment to see if the y could do it; not as a way to actually grow an ear that could be worn by someone else. you would have all kinds of issues with rejection and such.


jc

 

[thebabydoc]

OMG the irony of this post is off the scale.

JC

LOL!!!
HEheheheh
Bwhahahaha!!!!!
he hee hoo hoo!!!!!
ROTFLMAO!!!!


babydoc

 

[thebabydoc]

"One, who, through the fault of his parents conception, is a skid mark in society's collective underwear."

You, my good sir, are an assclown.
http://www.urbandictionary.com/define.php?term=assclown

Can I nominate the topic since none of you girls are willin to step up? What about the entrophic pathway common to the steam cracking of ethene within bioreactor design? Make it easier - just at steady-state...

You got me there, good sir- because steam "cracking" is not performed on ethene, rather than to precursors to produce ethene as I have described below. As for "entrophic," I have no idea what that means, I'm not sure it's even a word. Did you mean endothermic?

Ethene can be produced either by

Extraction from natural gas using fractional distillation followed by steam cracking (the technique for converting alkanes to alkenes)(750 - 900oC) followed by liquefaction of the gas (-100oC) and then further fractional distillation
OR
Extraction from crude oil using fractional distillation followed by steam cracking(750 - 900oC) of the naphtha or gas-oil fractions followed by liquefaction of the gas (-100oC) and then further fractional distillation.

The cracking process typically involves endothermic equilibrium reactions such as:

C2H6(g) C2H4(g) + H2(g) H = +138 kJ mol-1
C3H8(g) C2H4(g) + CH4(g) H = +81 kJ mol-1

To maximize the rate of the cracking reactions

1. the temperature can be increased so that the gas particles move more quickly and collide more often
2. increase the pressure which forces the gas particles closer together and collide more often
3. no catalyst is needed to increase the rate of this reaction since the steam provides the required activation energy

To maximize the yield of ethene, by Le Chetalier's Principle

increasing the temperature of the reactions favours the formation of products since the reactions are endothermic. So increasing the temperature speeds up the rate of the reaction and increases the yield of ethene.
a decrease in pressure would favour the the formation of products since there are more gaseous product molecules than there are gaseous reactant molecules. However, a decrease in pressure would slow down the rate of the reaction. For this reason the pressure is kept at or below atmospheric pressure.
removing the product will favour the formation of more product thereby increasing the yield of product. Equilibrium is therefore never actually achieved.

Now I don't know much about bioreactor design, but I can only guess that your poorly worded question asks how is this steam cracking process used within bioreactor design?

My guess is that you're merely referring to the fact that the steam, by virtue of increased pressure and temperature facilitates the breakdown of higher alkanes into lower alkanes which can then be easily dehydrogenated into hydrogen gas (H2) and Methane (CH4) as well as ethene and propene.

What you do with the coke byproduct I still can't understand.
Problem is that steam cracking has a low selectivity, is highly endothermic, and you still have that coke byproduct to deal with.

Personally, I would prefer straight ethane, propane, or butane dehydrogenation or even methane coupling as alternative processes.

Or did I over-analyze and by refering to the "steady state" were you in fact referring to the propagation step of steam cracking, in which case the answer would be:

H3C + H3CH3 --> CH4 + H3CH2

H3-CH2 --> H2C=CH2 + H
H + H3CH3-CH3 --> H2 + H3CH2
H3CH2 --> etc...


thank you for playing.....assclown

 

[thebabydoc]

What a joke.

He needs to leave his little nest and actually travel to other countries for a change.

CNN is not culture.

Didn't we already have this one out on the "I've been to more countries than you thread you started?" If I remember that one right, I'd beat your present total by age 18, even if you're now counting Texas as a country (which, as everyone knows, it is).

Spent- be a doll and look that post up for me, would you, I've got like 235648735238 more important things to do than REPEAT my evicerations of Fonz.

 

[thebabydoc]

bump for Mandinka2's reply

 

[spentagn]

At risk of being called "babydoc's bitch," I shall refrain from looking up said thread. But I do recall it

 

[KAYNE]

BABYDOC

MY EX'S DAD IS A DOCTOR. HE IS WELL KNOWN IN HIS FIELD THROUGHOUT THE COUNTRY. HE IS ALWAYS TRAVELING AND SPEAKING AT CONFERENCES AND WHAT NOT. HE IS A CARDIAC ANESHTESIOLOGIST. HOWEVER, HE REALLY IS ONE OF THE DUMBEST PEOPLE I HAVE MET. MAYBE HE IS JUST SMART IN HIS FEILD AND NOTHING ELSE. IS THAT COMMON FOR A DOCTOR? I'M JUST WONDERING CUZ YOU SOUND AS IF YOU HAVE A PRETTY WELL ROUNDED EDUCATION.



KAYNE

 

[thebabydoc]

Most docs I know are fairly well-rounded because of the requirements for getting into med school 10-20 years ago. But with 6-year med programs and newer admission criteria, more and more docs are just plain poorly-exposed.

Certain specialties tend to harbor some of the "dumber" docs and anesthesiology is definitely NOT an exception here. All of this also is often dependent on how difficult it was to get a residency position at the time that particular doc chose his specialty. To this end, family practice residencies have always been easy to come by...

 

[KAYNE]

LOL.......I CALL HIM THE "DUMBEST SMART MAN I KNOW" SINCE HE IS SUPPOSED TO BE SO GOOD AT HIS PROFESSION BUT IN EVERYDAY LIFE, HE IS JUST PLAIN STUPID TO EVERYTHING.



KAYNE

 

[p0ink]

babydoc,

how easy is it for someone to do a medical history check on you? are they able to find out every scarp of information from every doctor you've been to? or are they only able to find out information from the doctor you give them? or is it based on which insurance you use?