Flourinert is significantly inerior to water in heat capacity terms. On the other hand leaks are no problem for electrical issues as you can dip the whole system in it without it frying.

I see from the link above that it has a high vapor pressure, but if the heat content is low then I am not interested. The dielectric properties are nice, though. I still may build a bath system some day...and sold in 100 mL bottles...

Fluorine used to be used in some automated cleaner / degreasers -pretty good stuff.

I can't relate to the surface tension figures. Will the stuff "wet" a copper surface?
Anyway -if it is not a good coolant, then I am not interested...and it is hazardous.

Don't dunk your hard drives in it :shock: they are designed to run in air, not liquid! Otherwise, I have seen people use mineral oil (often refrigerated to sub zero temps) as a full immersion bath. It would do about the same I expect, be far less expensive and lower environmental risk.

Gooserider

Oil is somewhat more viscous in general, especially at low temperatures.

True, but if you cool the system tank, that doesn't matter. It isn't something I'd do, but there are lots of threads on it over in the radical cooling (phase change) area.

Gooserider

Re: UV Light to Kill W/C Bacteria
 

HI , guys i need help from all the expert here, Im an undergraduate student, with mild knowledge of UV light, currently , im in a grp and doing a design project, we want to create a closet which can drying clothes , we design a closet with with air flow fans. other than, that we need a uv light that enable to kill bacteria avoid the clothes get smelly after dry

requirement-
1) low budget( priorty) (if too expensive that would be no market)
2) simple
3)function -just avoid the clothes get smelly bcoz of bacteria
4) optional ( avoid fungi grow in the closet )


anyone is welcome to give sugggestion, guys pls help!!!!!!!!!!!!!!!!

Re: UV Light to Kill W/C Bacteria
 

Would'nt high levels of UV fade clothes if used alot?

Re: UV Light to Kill W/C Bacteria
 

Depends upon the level of UV. In dry climates, you don't need as much UV. Clothesline drying. Put stuff in there damp, and... you'd need a lot more UV.

Re: UV Light to Kill W/C Bacteria
 

IMHO you're going to have problems with not all parts of the clothing being exposed to the UV (even if you get that part working). Yes, you could have a UV sterilizer and force air through it - but I'd expect that that won't kill mold/mildew/bacteria on/in the wet clothing.
Maybe use ozone? Of course, that'll fade the clothing as well - but at least it'll get to the articles that would have been "shadowed".
Or were you planning to dry one thing at a time? You might have some marketing issues if so... :)

Re: UV Light to Kill W/C Bacteria
 

Does anyone hv anything can prove that UV cause the clothes fade? coz clothes fade may not bcoz of UV , it may due to other factor causing it , further UV light that is being generate by a lamp , may different from the UV is generated by sun light? Anyway, our testing for this product will start soon , see hw it goes , for solving the problem not all part of the clothes are exposed to the sun light, actually its pretty simple , just use reflection method . Anyone know something about this, really wish you can provide any opinion. thx a million for those give ur precious comment.

Re: UV Light to Kill W/C Bacteria
 

Google.
http://www.google.com/search?q=sun+faded
http://www.google.com/search?q=sun+bleached

Edited for typo and added another search term.

Re: UV Light to Kill W/C Bacteria
 

Ok you don't HAVE to use UV to kill the bacteria do you? why not just raise the temperature sufficiently, like a normal tumble dryer? Ontop of that, You can use indirect UV light to kill the bacteria in the air before it hits the clothes, then spray the clothes down with febreeze antibacterial? or something like that.

Anyways, sunlight does make clothes fade, along with many other pigments. And UV light causes many polymers to break down after longterm exposure. In either case, direct UV exposure probably isn't a good idea. Any place the UV light can't reach, won't be sterilized. e.g. the inside of a shirt.

Perhaps you should rethink the concept? Ditch UV all together and just use typical ways of killing bacteria? (dry atmosphere, high heat, perhaps a chemical sterilizer?) If you're really ambitious, i've seen ultrasound used to sterilize in some applications. And of course theres always good old fashioned steam. UV light usually isn't good unless its for a liquid application.

And to think i'm going into poly sci... i really should have applied for engineering instead... i enjoy it so much more =/

Oh yes, before i forget. You should look into which wavelength of UV light causes what types of pigments to fade. If its a serious project, like 4th year final or something, then i say go the whole 9 yards.

Re: UV Light to Kill W/C Bacteria
 

UV causes some complex molecules to break down because of the energy imparted.

Re: UV Light to Kill W/C Bacteria
 

I have a feeling that anything that will kill baterica will also destroy fabrics and colours as both are organic compounds

Talcite speaking as someone who turned down physics (probably at cambridge) for engineering i think that engineering is far better. There is a large amount of overlap at the top end though. Engineering teaches you alot more about basic stuff which is useful while physics is alot quite abstract or focused. Engineering is also better as there is much more group work and soft skills which job interviewers love. If you really feal like it do an MSci afterwards to becoem an engineer. I know a few people who do that. Ones doing a maths now then aeronatuics at MIT later for examples.

Re: UV Light to Kill W/C Bacteria
 

thanks for the advice bobo. Yeah, i really do like building things. I've built several robots for competition and electric cars, and things like that. The thing i'm worried about is my math. Its quite rusty, and after a 4 year degree in the arts... i'm not sure if i'm going to be able to factor at all 0.o I've already forgotten most of calculus, and its only been 5 months. =/

Re: UV Light to Kill W/C Bacteria
 

I agree with bobo. Engineering lets you play with toys and make things. Physics (and other abstract studies) tend to lead to lots of politics, papers and red tape (from what I've seen).

In software, the dichotomy is between writing software or writing grants. I'd much rather fight deadlines than my "fellow" faculty. Backstabbing is an art that seems well developed in academia and other rarified research areas.

I hope I'm understanding where you are coming from, Talcite.

Re: UV Light to Kill W/C Bacteria
 

lol i'm not sure you do brian. Poly sci is short for political science 0.o I'm going into the arts >.>' lol not for polymer science or something heh. I was sorta confused when everyone started talking about physics all of a sudden =p

Re: UV Light to Kill W/C Bacteria
 

UV is just short wavelength radiation which can be ionizing or not depending on frequencies that you are letting through. I was thinking about this path but the items here mentioned (about limited coverage area/hidden bacteria, and added heat issues of including this in the loop (not to menion power requirements to run it). Has anyone used or tried out low level radioactive material? (radium, polonium, et al?) Figure it would be a good fit here.

Re: UV Light to Kill W/C Bacteria
 

Ouch -I am almost scared to respond to that. Let's see where this goes...

I have some tritium capsules...think they would be powerful enough to do anything?

These are tiny items used in night sights for firearms and I think tritium has a half life of 10-15 years.

Re: UV Light to Kill W/C Bacteria
 

Actually I do remember previously discussing mutant algae and bacteria...

Re: UV Light to Kill W/C Bacteria
 

I've got a lot of tritium as well (same reason, night scopes, front sights to guns et al), but I doubt it would be enough, don't know.

As for Polonium I have that as it comes with a lot of the 'anti-dust' brushes you get w/ photography and lasts for several years. It's enough for a static charge (which is how they are used) but also don't know about anti-bacterial concentrations.

Other ionizing radioactive material in older smoke detectors et al could be a possiblity but would guess expensive for what you actually get (they don't use much at all).

Just thinking out-loud here, the main concern that comes to my mind would be interferance w/ the computer electronics but with alpha emitters the distance is too low (and the closest you have to teh cpu would be waterblock and the copper there would be MORE than thick enough to stop that).

Re: UV Light to Kill W/C Bacteria
 

Need to look back through here to find the power required to kill said nasties and then do some math.

Re: UV Light to Kill W/C Bacteria
 

I wonder if anyone has used arsenic in their coolant? It works well to kill bacteria in some of the streams in Utah/Nevada. Sounds a heck of a lot safer than putting radioactive material inside a computer that can crash when an alpha particle crashes into a gate or memory capacitor.

Re: UV Light to Kill W/C Bacteria
 

Any idea if the soluble form is reactive with the metals we typically use?
Sounds like a good solution (pun not intended - I'm too hot to be joking ;) ) otherwise

Re: UV Light to Kill W/C Bacteria
 

Arsenic may be very reactive with aluminum. I saw what looked to be an arsenic removal technique using activated aluminum. Also, it is a biocide which seems to be quite poisonous to humans. I see reference to cancer, SIDS and autism, to mention a few.

Is the danger less than is what is feared? Would the amount of arsenic in the water be dangerous? Would it escape or form an almalgam with the aluminum?

Needs a good chemist to answer.

Re: UV Light to Kill W/C Bacteria
 

I'm not sure if the basic assumption of all this is correct: all ionizing radiation kills bacteria?

I'm sure with the right intensity, you could kill bacteria... hell you could kill people and animals. The thing is though, how do you know what intensity and wavelength of radiation you're using?

Anyways, I can think of one example that disproves this assumption. UV-A and UV-B both are ionizing radiation, yet they arn't useful for sterilizing water. UV-C is actually what is used, with a wavelength of less than 280nm.

I did a bit of reading on wiki, and it turns out that all UV-A, B and C cause dimerization, CG bonding in DNA. Anyways, for some reason, high dose UV C is the choosen method of sterilization. I doubt any other creative methods of sterilization via radioactive materials would work, other than to create some highly unique strains of algae in your loop =p.

So do what you guys want, but some of it might be useless, some of it might be pointless, and well some of it might just make you sterile =p

Ahh... and Brian, here you go http://physchem.ox.ac.uk/MSDS/AR/arsenic.html
Basic moral of the story. Don't touch arsenic, we like your w/c work, and you have to be alive to work on it =p.

Oh and you see where it says IPR-MUS LD50 46mg kg-1? That means that by 46mg per 1 kilo material concentration of arsenic entering a mouse's abdominal cavity (i.e. absoption though skin, direct injection etc... ), it killed 50% of the test subjects. Not a very nice number, considering you'd be using much more arsenic than 46mg/kilo. Best you just avoided it all together =p. (1000 mg = 1 g. 1000g = 1kg...)

I'd say just use black tubing and don't let any light in... Money and time saved there. But if you have to, use the aquarium UV sterilizer.