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March 16 Information
Practical magnetics problem
If a magnetic material is fully saturated, will it exhibit any loss to an applied alternating magnetic field? In other words, what is the value of u when the material is magnetically saturated?--
31.55.104.196 (
talk)
00:20, 16 March 2014 (UTC)reply
Certainly a material can become "saturated," but in view of the exacting language in "any loss," I wonder about "fully saturated" since the B field approaches an asymptote, but can always increase a tiny amount if the H field increases, according to
Saturation (magnetic).
Edison (
talk)
22:43, 16 March 2014 (UTC)reply
Philip Experiment.
Philip experiment on youtube. I know it is probably a hoax, but I still don't understand what was really going on even after I read the article? The group probably imagined all the noises. My question is was the table really moving by itself? Was the table actually floating above the ground by itself? If the floating table was just the participants' hallucinations then how can I see it in the video? How could they capture their hallucination on video? Or was there some kind of trick behind the scenes?
75.168.134.220 (
talk)
06:52, 16 March 2014 (UTC)reply
That video is a documentary about the experiment, as the description says: "A story about this experiment done in the early 1970's". None of it is actual footage. --
140.180.249.239 (
talk)
07:41, 16 March 2014 (UTC)reply
It's widely known that when protecting yourself against a man, kicking his testicles is a good way to cause extreme pain. What about women? Where should one strike to cause the most pain for the least force? --
140.180.249.239 (
talk)
07:31, 16 March 2014 (UTC)reply
Considering that men are generally stronger than women, they may simply restrain women without the need to hit them. But in extreme cases and when you don't know any
submission hold, my bet would be
celiac plexus, as in addition to pain hitting it induces temporary breathing problems (but even then - do not hit by knee!).
Brandmeistertalk11:19, 16 March 2014 (UTC)reply
A blow to the kidneys is extremely painful, but you have to hit a person on the back (to the side, just above belt level). That's not particularly useful for self-defense, though.
Looie496 (
talk)
14:00, 16 March 2014 (UTC)reply
"kicking his testicles is a good way to cause extreme pain." One who has studied judo might question that it is a "good way" for an attacker without training, since anyone with a little training in judo might be able to dodge the kick and grasp the attackers foot, leaving the attacker very vulnerable to the defender's move of sweeping the attacker's other foot out from under her, causing her to fall on her back. It would be a good way for someonewell trained in martial arts to attack a man.
Edison (
talk)
00:46, 18 March 2014 (UTC)reply
There's a
simple solution for that. Seriously though, every move has a counter. Can't let that dissuade you from trying. Natural kick/knee to aim, and all one really needs to remember is "hard as possible".On your back isn't the worst place for continued nutkicking, anyway. Worth the risk, in a serious situation. Unless you've some unblockable strike you're not telling us about.
InedibleHulk(talk)21:38, 19 March 2014 (UTC)reply
HYH.124, are you asking how to obtain the ratio? It's very simple: just measure the waist, then measure the hips (at positions shown in the
article you link), then divide the first by the second. Ideally your answer should no more than 0.7 or 0.9, depending on your gender. Please clarify if you were asking about something else.
Dbfirs09:42, 16 March 2014 (UTC)reply
The right-hand example in the picture of
waist–hip ratio illustrates a high ratio. Also from the article "abdominal obesity is defined as a waist–hip ratio above 0.90 for males and above 0.85 for females".
Dbfirs10:10, 16 March 2014 (UTC)reply
1)
Elastic deformation. This is the type of deformation where the object returns to it's original shape once the force (engine weight, in this case) is removed.
2)
Plastic deformation. This is the type of deformation that does not return to it's original shape.
Most materials first undergo elastic deformation with a small force and then plastic deformation with a larger force, although how much of the total occurs in each range varies wildly (with
elastic having a larger elastic deformation range and
plastic having a larger plastic deformation range). Metals have moderate amounts of deformation in both ranges. So, as long as the force (engine weight) is kept below the line where plastic deformation will occur, then the sagging under the engine weights won't bend the wings permanently.
If this was an issue, I'd expect supports to be mounted under plane wings while on the ground (I do expect they would add supports when doing work on the wings which lessens their strength for a while). Also note that aerodynamic lift causes the wings to bend upwards while in flight. This bending down when on the ground and back up in the air could also lead to
metal fatigue, but that's another issue.
StuRat (
talk)
15:13, 16 March 2014 (UTC)reply
The weight of engines on the wing, fuel in wing tanks, and weight of the wing structure cause the wing to deflect but the wing does not deform. Permanent deformation is prevented simply by building the wing strong enough to avoid permanent deformation, even under the most severe loads likely to be imposed on the aircraft in service. This is no different to designing a bridge or a multi-storey building so that it can withstand all loads likely to be imposed on it in service.
Locating engines on the wing is actually much better from a structural perspective than locating them on the fuselage, such as on the
Boeing 727 and
Hawker Siddeley Trident! When the aircraft is in flight, the
lift on each half-wing (the left half-wing and the right half-wing) is pushing the half-wing upwards, creating a substantial
bending moment that reaches its maximum at the wing root, next to the fuselage. If an engine is located on each half-wing, the weight of the engine is pushing downwards and causing a reduction in the bending moment at the wing root. This phenomenon is called bending moment relief and it allows the airframe designer to use less metal in the wing structure and this leads to a lighter airframe. In contrast, the engines in the Boeing 727, Trident etc provide no bending moment relief. Engines buried in the wing root, adjacent to the fuselage, as seen in the
De Havilland Comet and the
V bombers, provide a little bending moment relief but not as much as engines located further outboard on the wing. Four-engine aircraft such as the
Boeing 747 achieve substantial bending moment relief, especially from the outer engines. The maximum bending moment relief is achieved by moving some of the aircraft's weight to the tip of each half-wing; this explains the fuel tanks on the wing tips of some aircraft such as the
Learjets and
Mitsubishi MU-2.
Dolphin(
t)23:37, 16 March 2014 (UTC)reply
It's a
moth, for starters. Not sure of the specifics, but I'm almost certain the same kind are on my house every August in Northern Ontario. Might help. Of course,
lepidopterists are a picky bunch. May have a slightly different cousin there.
InedibleHulk(talk)13:31, 16 March 2014 (UTC)reply
Yes, a moth. That dude
looks like a lady. Mine have those feathery ones. Shorter, too. I think the views are good (high detail, too), if someone smarter on moths than I sees them. If nobody like that shows up here, you can try sharing the picture with
BugGuide.InedibleHulk(talk)14:42, 16 March 2014 (UTC)reply
This photo reminds me of a
wooly bear (
Isabella Tiger Moth), but the black markings are much weaker than those in
[1] and the coloration seems more orange. Either it's simply a color phase from a region not often represented in this photo collection, or some other species, likely somewhat closely related.
Wnt (
talk)
15:44, 16 March 2014 (UTC)reply
Oh! I was hunting for something in northern Ontario... since that wasn't shown, it might even have been the wooly bear. I should see what related species exist in Pakistan...
Wnt (
talk)
01:53, 19 March 2014 (UTC)reply
It turns out that there are a
lot of types of Spilarctia that might have ranges in the area, and have an appearance somewhat similar to this one, but not quite right
[2]. But I'm not finding good photos for most of the species in the web searches. Trying to identify a lepidopteran from photo comparisons is already unreliable enough, but take away the photos and it's quite a problem!
Wnt (
talk)
02:12, 19 March 2014 (UTC)reply
It is always mentioned by many military experts that Russian tanks require more maintenance than western why ? and what are the maintenance requirements generally in a tank ?
Tank Designer (
talk)
13:36, 16 March 2014 (UTC)reply
Russian main battle tanks are more likely to be used close to home (say for invading the
Ukraine), so sending them home for maintenance is more feasible than US tanks, unless the
US plans to invade
Canada or
Mexico. This fact may have affected the maintenance specs for each.
StuRat (
talk)
15:24, 16 March 2014 (UTC)reply
Or
Cuba? But first, I'd like to see these "military experts". For many kinds of equipment, Russian/Soviet designs are more rugged and require less maintenance than the Western equivalent. Compare
AK-74 and
M16, or, historically,
Panther tank and
T-34. --
Stephan Schulz (
talk)
15:31, 16 March 2014 (UTC)reply
I don't see the US invading Cuba, as it's simply not militarily important enough to warrant an invasion anymore (unless they offer to host Russian nukes again). And if the US did invade, they could do tank maintenance at
Gitmo.
StuRat (
talk)
16:55, 16 March 2014 (UTC)reply
Can anyone tell me what are the maintenance aspects in the tank engine or give me a link so I can read it alone ?
Tank Designer (
talk) 17:01, 16 March 2014 (UTC)
I′m not bigoted to western weapons , most of my information is derived from English documentary videos which are almost bigoted to their countries,sorry for my weak English I′m Arabian .
Tank Designer (
talk)
17:11, 16 March 2014 (UTC)reply
The major difference is philosophical rather than technical: Russian doctrine calls for military vehicles to be used for a certain number of operating hours with no field maintenance, then returned to the factory or a maintenance depot for a major overhaul regardless of need: this lets them operate a large number of vehicles with a small number of skilled maintenance personnel. Western doctrine calls for military vehicles to be maintained in the field by skilled personnel, only returned to a depot in the event of major damage: this requires more skilled personnel, but has fewer vehicles unavailable due to maintenance at any given time. --
Carnildo (
talk)
01:42, 19 March 2014 (UTC)reply
I want to get hold of a curve describing how visual acuity changes when a test object moves from the center (fovea) to the periphery. Anybody knows where to get this information?