Wikipedia:Reference desk/Archives/Miscellaneous/2012 August 13

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August 13

Triace brand bicycles?

Hi everyone. Can anyone point me in the direction of some ENG language reviews of Triace brand bicycles? They are huge here in China with products in every market segment, but the only ENG references I can find are to models being sold through Wal-mart, which is not exactly a confidence builder! Ideally something would compare/contrast them with Merida or Giant or some other such well-known brand... Thanks. The Masked Booby (talk) 00:39, 13 August 2012 (UTC)

A quick google search revealed this: http://runreview.blogspot.no/2011/06/triace-s503-bike-review.html DI (talk) 09:42, 13 August 2012 (UTC)

Sheldon Brown and others discuss the development cycle of bicycle production and industry shift. It may be that Chinese manufacturers are at a point where they are starting up the quality ramp, but that price has not followed. There's something of a video review here: http://www.youtube.com/watch?v=r8pwfS3jTvU . Fifelfoo (talk) 02:17, 14 August 2012 (UTC)

Turning wind pressure into weight

We've all seen large windturbines on hill tops. I would like to know if the large blade (propeller)was virtical how much weight would it take to rotate the turbine motor in working mode.150.101.204.218 (talk) 05:05, 13 August 2012 (UTC)

This is probably better asked at the Science reference desk. Those boffins know about such things. -- ♬ Jack of Oz ♬ ^{[your turn]} 05:25, 13 August 2012 (UTC)

Much as it pains me to admit, Jacky O is prolly right. But doesn't the IP mean, "Were it horizontal,...?"? μηδείς (talk) 05:42, 13 August 2012 (UTC)

Yes, correct use of the subjunctive would be along the lines of "Were there fewer unpleasant grammar pedants on the Reference Desk, it would be a more pleasant and productive part of the project." TenOfAllTrades(talk) 13:37, 13 August 2012 (UTC)

Well most us who like to see correct grammar and spelling can cope with "virtical" for "vertical", and might even use "if it was" informally for the pedant's "if it were", but I think Medeis was just distinguishing vertical from horizontal. Dbfirs 14:53, 13 August 2012 (UTC)

Exalctly. μηδείς (talk) 18:25, 13 August 2012 (UTC)

Ah, well. I feel silly for failing at reading comprehension. TenOfAllTrades(talk) 14:57, 13 August 2012 (UTC)

It doesn't really matter where the question is asked, there is no possible way to answer it. The blades are balanced, so the answer comes down to friction, and the level of friction inside a wind turbine depends on countless things. Looie496 (talk) 15:45, 13 August 2012 (UTC)

You may be interested in this thread: Physics Forum: force needed to turn a windmill generator? which I didn't really understand, not being a boffin and all . You may also find some information in RenewableUK Briefing Sheets - How does wind energy work?. Alansplodge (talk) 17:14, 13 August 2012 (UTC)

Given that for efficiency reasons the friction is very low, the mass required would also be very low. If the mass is placed on the outer edge it will not have to be as large as if it is placed closer to the centre due to mechanical leverage. 203.27.72.5 (talk) 22:28, 13 August 2012 (UTC)

I'm not an expert on large commercial turbines, but from my experience of much smaller wind generators, I would comment that the torque required varies depending on the orientation of the blades with respect to the generator magnets, so will vary up to a maximum at a certain position. (The geometry of large turbines is probably more sophisticated.) The weight required just to overcome friction (with the generator disconnected) will be very small, as mentioned above. Weight will be most effective when applied at the tip of a horizontal blade (to maximise torque), but the much greater weight required in generator mode will depend on the power of the generator and the configuration of the generator mechanism. (The answer to the question as asked is that no amount of weight, however great, attached to the top of a vertical blade will turn it because the line of action of the weight will pass through the centre of the rotor, thus generating zero torque. Of course, a very slight displacement from the vertical will change the unstable equilibrium.) Dbfirs 06:54, 14 August 2012 (UTC)

Passing the world record but not getting gold

How common is it for an athlete at the Olympics to best the pre-Olympics world record mark but not manage to get a gold medal? In the current games, Im Dong-Hyun broke the world record in his archery event during a preliminary round and then failed to medal at the finals. In weight lifting, Tatiana Kashirina beat the pre-Olympics world records for both the snatch and combined totals in her weight class, but missed a gold when Zhou Lulu managed an even higher combined weight. How common are outcomes like this, where someone breaks the world record but still doesn't get to the gold medal in the end? Dragons flight (talk) 12:13, 13 August 2012 (UTC)

I don't know if anyone has crunched the necessary numbers, but it happens more often than you think. This year's Olympic swimming championships included both gold and silver medallists breaking the old world record. I'll have a go at finding that. --TammyMoet (talk) 16:02, 13 August 2012 (UTC)

Couldn't find that one. I think I was thinking of one of the races where the old Olympic record was broken by gold and silver medallists. --TammyMoet (talk) 10:42, 14 August 2012 (UTC)

So did the men's relay in track. Rmhermen (talk) 16:17, 13 August 2012 (UTC)

The GB Women's pursuit cycling team broke six world records in six consecutive runs in the same event (the last won them a team Gold)[1]. Alansplodge (talk) 17:22, 13 August 2012 (UTC)

For racing events there is a little logic issue to be careful with. If the first place getter breaks the world record, then their time is now the world record, so the second place getter cannot ever beat the world record in the same race. Tammy's statement is accurately written. Gold and Silver medallists may both have beaten the OLD world record, but not the current world record. HiLo48 (talk) 17:29, 13 August 2012 (UTC)

I suspect that the question is based on the premise of a new world record being set in the heats of the event, but not bettered in the final; which is often a more tactical race than a record attempt. Apologies if you had already appreciated that and I misunderstood your last post. Alansplodge (talk) 17:39, 13 August 2012 (UTC)

Please note my use of the words "in the same race". I think we're on the same wavelength here. HiLo48 (talk) 18:01, 13 August 2012 (UTC)

There was the case of the women's team sprint team from China who beat the world record in the qualification round, beat their just set record in the first round then were relegated in their final race against Germany meaning they ended up with the silver (their time before relegation was faster then Germany but slower then even the old world record) [2] [3].

Of course in most sports what you did in earlier rounds doesn't count, only what you did in the final round. While not setting a world or even olympics record Vitezslav Vesely threw a 88.34m in qualification round, nearly 4 metres clear of anyone else in either the qualification or final but failed to medal after throwing nothing better then a 83.34m in the final round. The surprised Trinidad and Tobago athlete Keshorn Walcott was the gold medalist (only the second ever olympics gold medallist for his country), as our article says "becoming the youngest-ever Olympic champion in javelin throw[4] and the second non-European to ever win the Olympic gold in men's javelin throw since Cy Young" and http://www.london2012.com/athletics/event/men-javelin-throw/phase=atm053900/index.html]).

Nil Einne (talk) 19:16, 13 August 2012 (UTC)

Warren Potent equalled the world record to qualify for the Beijing games, but ended up with the bronze. 203.27.72.5 (talk) 22:22, 13 August 2012 (UTC)

Historically, the most spectacular examples were, possibly:

• 1968 triple jump WR increased once in the heats and four times in the final, with 5 men exceeding the pre-games WR
• 1980 pentathlon WR broken three times in 1.6 seconds.

jnestorius^(talk) 17:10, 14 August 2012 (UTC)

Not Olympics (or not any more, anyway), but here's a possible oddity. Let's suppose Abel is on base and Baker is at bat. As it happens, they are tied for the all-time record in runs scored. Baker knocks it out of the park. Abel scores, and at that moment he holds the record. As soon as Baker rounds the bases and touches the plate, they're tied again. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:48, 14 August 2012 (UTC)

Motor oil on lawn

Hello--

I spilled about a quart of motor oil on my lawn, is there a way I can remove the oil without damaging the grass? Albacore (talk) 18:51, 13 August 2012 (UTC)

Putting cat litter on it will help soak up some of it. That's generally what people put on their garage floors to clean up oil drippings there. Use the old fashioned clay stuff. Dismas|^(talk) 20:17, 13 August 2012 (UTC)

(ec) I seriously doubt it if it already soaked in (I would assume it has since you took the time to get online and ask the question). Shadowjams (talk) 20:22, 13 August 2012 (UTC)

If you're afraid of pets licking it off the grass, you might want to blot the area with paper towels. You won't get it all, of course. StuRat (talk) 22:08, 13 August 2012 (UTC)

Are you thinking of antifreeze? Motor oil will just make them regular. μηδείς (talk) 02:07, 14 August 2012 (UTC)

If it's used oil, it will have various heavy metals in it and combustion products, none of which is particularly good to consume. It could also have tiny, sharp pieces of metal in it. StuRat (talk) 03:24, 14 August 2012 (UTC)

• You're screwed. It will kill the grass and any new grass you plant there. The only reliable solution is to dig up the grass and the oil-soaked dirt, put down new dirt, and replant. Looie496 (talk) 01:01, 14 August 2012 (UTC)

Agree exactly with Looie, nothing to be done but excavate and replace. Richard Avery (talk) 07:39, 14 August 2012 (UTC)

Used motor oil is also quite good at killing trees and many other things too, like all those things that live in soil (worms, slugs, etc.) That's probably why most countries have warning over the outside of oil cans telling you to take care with disposal. You will want to dig it up and put in new, clean dirt. Astronaut (talk) 11:17, 14 August 2012 (UTC)

And rather than dumping it in the trash, probably take it to a hazardous waste disposal center? ←Baseball Bugs ^{What's up, Doc?} carrots→ 13:27, 14 August 2012 (UTC)

Nano sponges [4].  Card Zero  (talk) 14:14, 14 August 2012 (UTC)

Here is the Material Safety Data Sheet for one brand of motor oil. Paper towels, could be used to blot it up when a small amount like a quart is spilled.on grass. Garages and utilities use absorbant devices with an outer fabric and an inner absorbant, which would avoid the problem of trying to collect the cat litter dumped on the oily grass. (Its easier when the spill is on concrete). It might well kill the grass anyway, and a quart should only contaminate a small area, so you might take grass cutting shears and lop off the contaminated grass near the ground, to reduce soil contamination. Edison (talk) 17:13, 14 August 2012 (UTC)

Astronaut has it. You state/locality may regulate disposal. I once had to help dig up part of the Mojave desert after 50 gallons of diesel was spilled. ---— Gadget850 (Ed) ^talk 17:42, 14 August 2012 (UTC)

There's a big difference between a quart and 50 gallons (200x). A quart will likely be absorbed by the ground and decompose, but 50 gallons may very well run off the next time it rains, and contaminate a river. StuRat (talk) 23:16, 15 August 2012 (UTC)