Wikipedia:Reference desk/Archives/Science/2016 July 15

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July 15

Durian Fruit

I have smelt 'Durian' but it is too stinky. What may be the reason behind its stinkiness. — Preceding unsigned comment added by Sahil shrestha (talk • contribs) 02:48, 15 July 2016 (UTC)

See our article - Durian#Flavour and odour - my guess would be the sulfur compounds and the reason for the difference in perception being related to the asparagus urine smell (see asparagusic acid) where some people don't detect / smell the sulfur compounds produced by the metabolites. EdChem (talk) 03:39, 15 July 2016 (UTC)

An important odorant is 1,1-Ethanedithiol. Graeme Bartlett (talk) 03:56, 15 July 2016 (UTC)

Identify this bird

I saw this very large bird sitting on my neighbor's deck yesterday. In Northern California, San Francisco Bay Area. I thought it might be a turkey vulture but the head is whitish rather than red and the neck doesn't really look like a turkey vulture. It's also pretty bulky for a vulture, so I thought it might be a wild turkey, but it doesn't seem to have a wattle, and I've never heard of wild turkeys living in this area. Photos: [1] [2] CodeTalker (talk) 16:13, 15 July 2016 (UTC)

I suspect it is a turkey - though a juvenile so the wattle isn't yet fully developed. The distribution map shows that there is a population in northern California and Oregon. Wymspen (talk) 19:21, 15 July 2016 (UTC)

Yes, that is clearly a turkey. Matt Deres (talk) 20:14, 15 July 2016 (UTC)

I agree that it looks more like a turkey, but just for completeness, take a look at the turkey vulture. Doesn't look quite like your bird. StuRat (talk) 21:26, 15 July 2016 (UTC)

I know someone in Albany who often reports seeing turkeys; I'm not sure whether they're running wild or belong to some neighbor. —Tamfang (talk) 09:34, 16 July 2016 (UTC)

Or maybe they are just watching election news. :-) StuRat (talk) 17:49, 16 July 2016 (UTC)

• Yup, t'is a turkey all right, you can't but not see Meleagris gallopavo back in my hometown (the northernmost in South Jersey), whether at dawn or dusk.

I could quit my job and lead tours, except everybody's at McDonalds or getting Pop-Eye's take-out that time of day.

These beasties've made such a comeback since the suburbs have replaced hunting the critters fer food it's downright dangerous.

Deer, raccoons, opossums, woodchucks have all literally exploded. (Mostly July 4th.) We even had that rabbit plague a few years back. They've crashed, but they're back too.

And here in NYC that have the rat clubs. Next it'll be flying lizards and freezing gorillers. Much of the US has greatly rewilded in the last century, and the commensals are doing just fine. Next it will be panders. In fact, my dad installed a cardinal-trap, although he's having a hard time finding willing suet. μηδείς (talk) 04:24, 18 July 2016 (UTC)

Let's hope that the gorillers and panders don't meet up with any iguaners. Sorry, I couldn't think of a llamer joke. Akld guy (talk) 21:36, 18 July 2016 (UTC)

A side view, showing the perforated nostrils.

Definitely Not a Turkey vulture. Our own article has this photo. Note the hook at the tip of the beak which has presumably evolved to help the bird tear at meat. The turkey is largely a herbivore (but does sometimes eat frogs, lizards or rodents) and has a very differently shaped beak, very similar to that in the OP's photos. DrChrissy ^(talk) 22:02, 18 July 2016 (UTC)

Computer UV LEDs effects on the body and electronic components

I am playing around with a custom liquid cooling system, and plan to use UV reactive tubing. To have the glowing effect on the tubing, UV LEDs are required (for example). I am hestitate to order because of the questionable effects of UV on the body (skin & eye) and on the computer components. I don't have the exact model of the UV LED (maybe something like this), and don't think the manufacturer will list the specifications either. But I would like to have some basic guideline and advices, thanks.

Additional information: I will be using a case with full temper glass side panel, which provides no place to hide the UV LEDs. -- Livy (talk) 19:27, 15 July 2016 (UTC)

The effect of UV LEDs on skin is the same as that of sun light - tanning (unless you use UV-C LEDs). So, nothing to fear. Ruslik_Zero 19:49, 15 July 2016 (UTC)

Not really, since it's very well-established that UV exposure increases your risk of skin cancer. Tanning is a response to skin damage from UV light. I would avoid any unnecessary exposure to UV light sources. You'll survive without glowy tubes. (And incidentally, I think liquid cooling for computers is a waste of money, at least for personal computers, but hey, it's your money, not mine.) --71.110.8.102 (talk) 20:02, 15 July 2016 (UTC)

I know. It is mostly for aesthetic purpose. -- Livy (talk) 20:47, 15 July 2016 (UTC)

(edit conflict) Tanning... and cancer. But of course, the question is how much radiation will be received, and eyes are more fragile than skin anyways.

@Livy: Wikipedia does not give medical advice, so you will not get an answer to the question "is it safe to do X". You can start at Mercury-vapor_lamp#Ultraviolet_hazards, though I tend to think that UV LEDs will be less dangerous than spectral lamps. I think a PC-building forum would be the place to go for more specific info about how to build your system (where to put which part); if the UV source goes inside the case so that you only see the luminescence, I would assume it will be OK from a health perspective. Tigraan^{Click here to contact me} 20:10, 15 July 2016 (UTC)

I am not asking where to put the UV LEDs. I know it is best to keep them hidden. In this case, I am wondering if the tempered glass reduces the effect of UV by any chance. I know what to buy for my PC system and where to put them. It is not really a medical matter either I think -- I am not searching for a solution to my illness. I just want to know the short and long term effects of consumer UV LEDs on the body and on the electronic components (if any). -- Livy (talk) 20:47, 15 July 2016 (UTC)

Tempered glass will not significantly reduce UV flux at the wavelengths that consumer-grade UV LEDs typically operate (350-400 nm). Dragons flight (talk) 20:57, 15 July 2016 (UTC)

Also, you can determine this by experiment. Does a length of UV reactive tubing still glow when the glass is between it and the UV source? If yes, then the glass does not block UV. It isn't a perfect test, but it is better than nothing and easy to do. BTW, while we cannot give medical advice, we can certainly give engineering advice about whether long-term exposure to UV LEDS damage computer motherboards. I am guessing no but I would like to see a source. --Guy Macon (talk) 06:24, 16 July 2016 (UTC)

I am not sure that UV LEDs in in the 350-400 nm range would cause any significant risk of skin cancer, which is mainly related to the shorter UV-C and UV-B ranges. However I agree that they are not eye-safe. Ruslik_Zero 20:22, 16 July 2016 (UTC)

You might consider hooking the UV LEDs to a separate switch and then only turn them on for brief periods when you are showing off. Many fancy cases have switches built in for controlling LEDs. Dragons flight (talk) 06:43, 16 July 2016 (UTC)