Chemical Forums

Please login or register.

Login with username, password and session length

Sponsored links

Pages: [1] 2 3 ... 10
 on: Today at 04:16:48 PM 
Started by 야마토카지노 - Last post by 야마토카지노
Comely is the 'say thank you you'
Wrapped with thanks,
Offered to peace prone people
Who proffer what is real-themselves
To treat with preference and servility
napalm asphyxiated victims
in our stained sphere
<a href=> 야마토카지노 </a>

 on: Today at 02:09:03 PM 
Started by vikram - Last post by vikram
Hi all,

While preparing sample for MALDI-TOF we come across two kinds of MALDI plates.One is Ground steel and another one is Polished steel.Is there any criteria while choosing the plates?Or is it just fine to choose any one among them?

Thank you:)

 on: Today at 07:55:25 AM 
Started by stickle - Last post by Borek
A lot depends on how fast you want to get rid of plastic. I agree with Corribus that polyethylene is easier burnt than dissolved, at the same time many years ago I have learned something interesting. I made a serious mistake - I left a polyethylene bottle near our fireplace. It melted, leaving a nasty stain on the grout. I have removed mechanically as much as I could, and a year later there were no traces left - apparently elevated temperature (in a place which can be typically safely touched with a bare hand) was enough to slowly decompose the polyethyelene. It can be impractical to keep something at - say - 120 deg F for several months, but it can work.

 on: Today at 07:47:29 AM 
Started by bubblegumpi - Last post by dolphinsea14
ChemDraw Ultra and Hyperchem are good.

 on: Today at 07:26:37 AM 
Started by Yoritomo - Last post by Enthalpy
Hi Kostas,

Foams are destroyed more quickly than plain polymers, but by the same compounds, so what you need is the compatibility of polyurethane (search keywords). Examples:
essentially, PU is degraded by acids, bases, oxidisers, ketones, alcohols and many more. Acetone would be my first candidate, but this depends also on the materials you want to keep.

Please be careful with explosive or toxic vapours, etc etc.

 on: Today at 07:04:37 AM 
Started by Gyvfdc - Last post by Enthalpy
In some occasions, the public is more confident than the experts. Think of sodium hydroxide to destroy organics in the sinkhole: chemists may well wear goggles for that. Nor would chemists pee on hypochlorite, would you?

Explosives are an extreme case. On new year's eve, the public ignites rockets with explosive heads from 0.5m distance. I know a few pyrotechnists, all told me "Never will I" and "Accidents are no wonder then".

Not to mention software...

 on: Today at 05:59:13 AM 
Started by stickle - Last post by Corribus
It's all blind speculation without knowing better what kind of polymer it is.  Polypropylene and polyethylene have much different stability to, e.g., UV light. I have no idea what a safe liner would be made from but plastic bags are almost certainly polyethylene, which is unfortunately very difficult to dissolve in anything, at least not without destroying the coin underneath as well. There's a caterpillar that can eat polyethyelene:

Honestly I think enthalpy's suggestion of controlled burning is probably the best bet. Silver's melting point is about 960 deg. C and manycommon organic polymers decompose at around 400-600 deg. C. If you could control the furnace temperature to be safely below the silver melting point but above the polymer decomposition temperature, you may be able to burn away the polymer while leaving the coins intact. Then clean whatever reside remains with a strong solvent. I wouldn't expect any kind of mint condition coin left over at the end though.

This does seem to defeat the purpose of a fireproof safe.

 on: Today at 05:50:46 AM 
Started by dolphinsea14 - Last post by dolphinsea14
Why temperature in casein isolation should be maintained at 40℃?

 on: Today at 05:04:44 AM 
Started by angel01 - Last post by Corribus
A fusion reactor would work.

 on: Today at 05:03:21 AM 
Started by Gyvfdc - Last post by Corribus
It's fundamentally a problem of risk perception and the fact that experts perceive risks different than laymen:

No one seems to deny that experts rationalize hazards against dosage and exposure. The public does not. For example, "the public would have more of an all or none view of toxicity....[T]hey appear to equate even small exposures to toxic or carcinogenic chemical with almost certain harm". As well put elsewhere, when a young child drops a lollipop on the floor, the brief contact with dirt causes the parent to throw it away rather than washing it off and returning it to the child.

(From: Berube, D. M. in Nanotechnology and Society: Current and Emerging Ethical Issues (eds Allhoff, F. & Lin, P.) 91–107 (Springer, 2009).)

The media doesn't help to dispel the notion that dosage in unimportant, and nor does it help to dispel the common perception that chemicals are just plain dangerous. In fact, people don't even seem to understand what a chemical is. When I see a consumer product like a lotion or shampoo being advertised as "chemical free", I just groan with annoyance.

Pages: [1] 2 3 ... 10

Mitch Andre Garcia's Chemical Forums 2003-Present.

Page created in 0.045 seconds with 12 queries.