Wikipedia:Reference desk/Archives/Miscellaneous/2009 November 1

= November 1 =

Why does the my "computer room" at home get so warm?
Ok, I have my desktop computer in a 10 x 15 foot room, with good ventilation. When I'm in there playing around on my computer after a few hours the room gets pretty damn warm -- so warm in fact that my face and neck get all sweaty, causing skin blemishes. I know the computer does put out some heat (I've heard that mainframe computer rooms from the 1960s and 70s got pretty hot), but really, is my little home computer causing all this? How much heat is this machine generating? Any answers? Torkmann (talk) 02:16, 1 November 2009 (UTC)


 * The heat energy it generates over time is almost identical to the power it uses, since all the energy has to end up somewhere and it pretty much all ends up as heat eventually. You can get monitors that go in-between the plug and the socket to measure that, but it will be in the order of hundreds of watts. You radiate about 1000 watts yourself. Altogether, that is a lot of heat. You need some way of removing that heat from the room. The main ways are ventilation and air conditioning (things like desk fans just move the heat around - you get a bit of evaporative cooling, but then you just end up with extra humidity rather than extra heat and that is no more pleasant). You say the room has good ventilation, but it would seem that isn't true if that room is getting significantly hotter than outside/the rest of the house (depending on where the room is venting to). I suggest you try and increase the ventilation - open the door, open a window, use a fan in such a way that it moves the hot air out of the room. If that fails, then consider air con. --Tango (talk) 03:18, 1 November 2009 (UTC)


 * Tango, I think you might have slipped a decimal somewhere. The amount of heat released by the average person is going to be on the order of a hundred watts or less, not a thousand.  The rest of your numbers look good, though.  (For the computer, an LCD monitor will add heat at around fifty watts; you can double or triple that for a CRT.  The CPU and other peripherals add another hundred to four hundred watts; higher numbers correspond to powerful graphics cards and processor-intensive games.)  So figure that the computer being there is like having anywhere from two to six extra people in the room with you. TenOfAllTrades(talk) 04:36, 1 November 2009 (UTC)


 * During some power strikes in Britain in the seventies companies with computers were allowed to keep them on. One mini was enough to keep the lights on but with a couple moved about they could keep a whole office heated. :) Dmcq (talk) 12:43, 1 November 2009 (UTC)
 * Well, I haven't got the number of noughts wrong, as such. I gave the gross amount radiated, you're giving the net amount (radiation minus absorption). With hindsight, your value is the more relevant to this discussion. --Tango (talk) 16:41, 2 November 2009 (UTC)
 * I'm not intending to question Tango's accuracy He's usually right!, but do humans really absorb heat at a rate of 900 watts?  Do tables and chairs do the same?  Is there such a high exchange of radiant heat in a room?  If so, then why does it take so long for a cold object (or cold limbs) to warm to room temperature?    D b f i r s   09:42, 3 November 2009 (UTC)
 * I think what is being said is that humans generate 1kW of energy. 90% of this is used to maintain internal body heat and to move around, digest food etc.  The 10% that escapes is the heat that the human radiates.  Googlemeister (talk) 14:29, 3 November 2009 (UTC)
 * Internal body temperature not heat is maintained, and the heat energy used equals the heat energy lost to the surroundings. There is no way for 900W to be lost to nowhere. I believe about 100W is the heat loss of a sitting adult. Cuddlyable3 (talk) 19:57, 3 November 2009 (UTC)

There's a lot of hot air on Wikipedia: presumably, it's moving into your room by convection, if my fusty memory of O Level physics serves me right. --Dweller (talk) 15:02, 4 November 2009 (UTC)

stop watching porn :) —Preceding unsigned comment added by 203.122.36.6 (talk) 19:11, 4 November 2009 (UTC)

coffee creamer
Bah, I just noticed that the main ingredient in coffeemate is corn syrup, i.e. glucose. Anyone know a good alternative that buffers the coffee's acidity (like cream does), and is non-perishable (like coffeemate), but doesn't have sweeteners? It's ok if it contains dairy products as long as they don't spoil. Something like powdered milk would be fine if I could get it in very small containers, as I only want to use about a teaspoon a day. But the supermarket seems to only have it in large boxes. Also, the big boxes say "nonfat dry milk", but for coffee purposes, I thought that fat was the main idea. 69.228.171.150 (talk) 04:59, 1 November 2009 (UTC)
 * I could be wrong (I don't drink coffee) but I was under the impression the primary reason most people add milk is for taste not to add fat. In any case, I would be surprised if you can't get full cream milk powder in the US (I presume you are in the US since you didn't say and it's there that corn syrup is most commonly used as a sweetener). You definitely can here in NZ. Nil Einne (talk) 07:50, 1 November 2009 (UTC)
 * Here in the UK you can get Carnation condensed milk in squeezy bottles, which should have the effect you're looking for. It's naturally sweet and I don't think it has added sweeteners (haven't got one handy so can't check). May be worth looking for condensed milk where you are! Oh and it shouldn't spoil, especially if you keep it in the fridge. --TammyMoet (talk) 09:14, 1 November 2009 (UTC)
 * Thanks, the idea of "nonperishable" is that I want to store it in a place where no fridge is conveniently available. I can get condensed milk in cans here, but I'd expect that once opened, it spoils quickly without refrigeration.  Interesting about the squeezy bottles.  I don't think I've ever seen those here (western US).  69.228.171.150 (talk) 09:56, 1 November 2009 (UTC)
 * Condensed milk almost always has added sugar, as a preservative. I'm almost certain that Carnation do not make an unsweetened condensed milk: if they do, it isn't on their site. It's evaporated milk that is usually unsweetened. 86.142.224.71 (talk) 16:08, 1 November 2009 (UTC)
 * I use cartons of skimmed UHT milk. 92.24.132.67 (talk) 20:09, 1 November 2009 (UTC)
 * How long do you need it to last? Milkettes of UHT milk are shelf-stable for extended periods. Matt Deres (talk) 20:35, 1 November 2009 (UTC)
 * It looks like the idea of UHT is that it's sterilized and sealed so it doesn't need refrigeration before you open it, but what about after you open it? I guess I'd normally put about 20ml of cream in a cup of coffee, so at 3-4 cups a week, if I can get UHT in 200ml containers (like juice boxes) I'd need it to last a month or so after opening, but if it's in 1 liter containers it would have to last much longer.  Coffeemate works pretty well except I didn't realize there was so much glucose in it. Update: I just looked at milkette and thanks, I didn't know before what those things were called.  The ones we get here usually have regular half-and-half in them and need refrigeration.  Plus they generate a lot of waste, as the article says, though my consumption is low enough that I guess I wouldn't feel too bad about it.  I'll see if I can find some UHT ones. 69.228.171.150 (talk) 21:48, 1 November 2009 (UTC) Update again: it looks like milkette is not a normal US term.  Web searches found mostly Canadian sources.  Anyway I'll check some restaurant supply places.  More suggestions are welcome.  Re Antilived: yeah, I mentioned some issues with powdered milk in the original post. 69.228.171.150 (talk) 02:19, 2 November 2009 (UTC)
 * Powdered milk? --antilivedT 22:33, 1 November 2009 (UTC)


 * Google suggests that the usual term in the UK is milk pots or jiggers, and they're easily available over here  but won't ship to the US. It seems there's also something called "Dairystix" that have the milk in a little plastic stick instead a pot (apparently cheaper than the pots), but they have an irritating website. My attempt to search for similar things in the US is hampered by Google's annoying increased tendency to remove any possible way for me to search without it being affected by my IP address.  Hope this gives you a few more search terms. 86.142.224.71 (talk) 16:19, 2 November 2009 (UTC)

Racemic mixtures in Drugs and Medications
When I purchase, say Aspirin or Acetaminophen at a drug store, are the pills in the bottle a racemic mixture of the levo- and dextro- enantiomers, with dextro- being the only active form?
 * If so, and if assuming that it is a 50/50 mixture, will taking twice the racemic mixture of aspirin be equivalent to one dose of the dextro- form?
 * Furthermore, if these assumptions are true, why do pharmaceuticals choose to do this?
 * Is it cheaper to manufacture drugs this way?

Thanks, Acceptable (talk) 20:05, 1 November 2009 (UTC)


 * You may want to ask this on the Science Reference Desk. Who then was a gentleman? (talk) 20:15, 1 November 2009 (UTC)
 * Honestly, I'd ask your local pharmacist. This gets dangerously close to medical advice, and I think we'd best avoid giving any definite advice, at least on the first bullet.  The others are, I think, more obviously fair game. Jwrosenzweig (talk) 23:06, 1 November 2009 (UTC)
 * Answering from a purely chemical point of view, aspirin has no stereocenters at all, see the structure below. Likewise neither does acetominophen.  See, d-l stereoisomerism requires assymetric tetrahedral carbons (that means an sp3-hybridized carbon with 4 different substituent groups).  -- Jayron  32  00:58, 2 November 2009 (UTC)


 * WHAAOE. Our article on enantiopure drugs says "One enantiomer of a drug may have a desired beneficial effect while the other may cause serious and undesired side effects, or sometimes even beneficial but entirely different effects. Advances in industrial chemical processes have made it economical for pharmaceutical manufacturers to take drugs that were originally marketed as a racemic mixture and market the individual enantiomers, either by specifically manufacturing the desired enantiomer or by resolving a racemic mixture". The article gives a list of pharmaceuticals that have been available in both racemic and single-enantiomer form. Gandalf61 (talk) 13:06, 2 November 2009 (UTC)


 * The nitrogen atom in acetominophen looks to be assymetric, except that the hydrogen can so easily swap sides on the nitrogen atom, that it would be a racemic mixture almost immediately. A quaternary nitrogen could be an assymetrical centre.  But your idea is right that the mixture may have only half the potency. But it does not apply to your example.  The dose information on the box should be correct for the content. Graeme Bartlett (talk) 21:19, 2 November 2009 (UTC)

A bathmat that does not go moldy?
I have a bathmat on the floor next to my bath. I often have to replace them as they get moldy quickly. Is there such a thing as a bathmat that never shows traces of mold? The mold usually initially appears underneath it in my experience. I do not mean the kind of plastic mat you put inside the bath to make it less slippery. 92.24.132.67 (talk) 20:20, 1 November 2009 (UTC)


 * Ours made of half inch thick cork is three years old with no sign of mould yet.--88.110.20.147 (talk) 20:35, 1 November 2009 (UTC)


 * One made entirely from a synthetic fibre like nylon will not (itself) go moldy, as the mold won't eat plastic, no matter how wet it gets. Like nylon shower curtains, such a mat will still get a bit moldy from the deposition of soap, shampoo, and skin that accumulates in it (but, like a shower curtain, is pretty easy to clean). But a nylon mat is probably going to feel a bit unpleasant to the naked food, and look a tad naff. I have a simple cotton mat, which I hang over the bath side once I'm done (so it dries out pretty soon) and that is machine washable (so it gets washed with the towels) - it doesn't have the (to my mind pointless) rubber backing that some mats have. If things in your bathroom are generally prone to mold (towels, the silcon seal around the bath, etc.) then this may indicate that the bathroom is in general poorly ventilated, and that you may need to run an extractor fan, or keep a window open, during or following a shower. -- Finlay McWalter • Talk 20:40, 1 November 2009 (UTC)


 * The rubber backing is not pointless. It's purpose is to prevent the mat from slipping underfoot. However, that makes cleaning the mat more difficult. Hanging it up to dry would be the best bet, although that should be supplemented by drying yourself as much as possible before you step onto the mat. ←Baseball Bugs What's up, Doc? carrots→ 23:42, 1 November 2009 (UTC)


 * Hang it up to dry. Convenient perches for this would be the top of the shower curtain rod or the rim of the bathtub. Bus stop (talk) 20:44, 1 November 2009 (UTC)


 * I agree that hanging it up to dry after showering keeps it from getting moldy. We've had the same one for years—gets daily use, but hanging it up (even just on the rim of the tub) after bathing keeps it dry and without mold. --Mr.98 (talk) 00:38, 2 November 2009 (UTC)

Simple poilcy is to gone that is fabric and wash it reasonably regularly. Virtually every (fabric) bathmat i've ever seen is machine-washable. 194.221.133.226 (talk) 10:23, 2 November 2009 (UTC)
 * Make sure to get one that will "grip" the floor adequately, or you could have take a major spill. ←Baseball Bugs What's up, Doc? carrots→ 18:39, 2 November 2009 (UTC)

What's the bathmat for? I don't use one so I don't know what people are trying to achieve, but there might be a novel alternative that fulfills that goal without being susceptible to mould. If it's to avoid an uncomfortably cold floor, for instance, I have seen hardwood gratings that I think look rather smart, and being close-grained oily hardwood they're pretty much impervious to damp. 93.97.184.230 (talk) 22:50, 2 November 2009 (UTC)
 * Stepping on a tile floor with wet feet could put you in the hospital. ←Baseball Bugs What's up, Doc? carrots→ 23:51, 2 November 2009 (UTC)
 * 'Scuse me? I walk on a tile floor with wet feet every morning. Are you saying I'm dicing with death daily? Why? 93.97.184.230 (talk) 08:39, 3 November 2009 (UTC)


 * It would depend on your age but tile-floors when wet (or your feet being wet) are slippery, a fall onto a hard tiled surface can cause a lot of damage, so yes. E.g. eldery people can easily break bones/cause serious damage, younger people can too though it'd be rarer. It's pretty obvious to anyone that's walked on a (polished, at least) tiled-surface with wet feet that without good concentration it can be very slippery. 194.221.133.226 (talk) 12:11, 3 November 2009 (UTC)


 * Sounds like the wrong tiles have been used, then. After all, swimming pools don't have this problem. I understood the typical elderly-person incident was slipping while standing in the *bath*, either showering or standing up to get out - hence the rubber mats mentioned earlier. My bathroom upstairs and also my kitchen, hallway, utility room and downstairs toilet are tiled, and I routinely walk in all of them with bare feet; wet ones too, in the case of the bathroom. I don't feel at any risk of slipping over. I presume that the tiles, being floor tiles designed to be walked on, are made very slightly rougher than wall tiles. There are four different kinds of tile across the rooms I mentioned, so it's not just one odd variety. 93.97.184.230 (talk) 19:47, 3 November 2009 (UTC)


 * While I agree that people are overstating the risk in a typical bathroom, I take issue with "swimming pools don't have this problem". There's a reason for the 'no running' rule: I've had to take a child to hospital, vomiting from concussion, after they tried to move too fast in the changing rooms. 86.142.224.71 (talk) 13:58, 4 November 2009 (UTC)

German Apartment Community
In a city in Germany, there is an apartment/shopping complex/community that consists of three connected chimneys or towers. It was an old pre WWII power or water supply station that was designed in the 1980's, I believe. What is the name of this complex and what city is it located in?99.54.5.209 (talk) 20:49, 1 November 2009 (UTC)


 * These are four obsolete gas tanks and not in Germany, but maybe it fits. The article is Gasometer, Vienna.  [[Image:vena 38.jpg|thumb|right]]  --Cookatoo.ergo.ZooM (talk) 21:44, 1 November 2009 (UTC)


 * Gasometer, Vienna should answer all your questions. There is also this article outside wikipedia. Royor (talk) 13:40, 2 November 2009 (UTC)


 * Minor correction: Briefly, they were, indeed, in a German city.  --Cookatoo.ergo.ZooM (talk) 17:44, 3 November 2009 (UTC)