Heat Exchange

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Question for anyone,

When dealing with water supply and return for induction coil boxes, does piping and hose size matter and what is the normal procedure for such an application? Let me know if more information is needed.

316 or 316L Dual Certification

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Hi Friends,

We require SS 316L material for some vessel welded internals due to H2S Service.

Shall I go for SS 316 material for internal bolt item which may not require welding.

Is there any requirement to go for dual certified bolts (SS 316 / SS 316L)...

Is it required?

Runaway star | Bad Astronomy

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"I am constant as the northern star,
Of whose true-fix’d and resting quality
There is no fellow in the firmament."
Julius Caesar (III, i, 60 – 62)

Shakespeare was a decent writer, but an astronomer he wasn’t. The North Star isn’t fix’d, because the Earth’s axis wobbles slowly like a top. You wouldn’t see this by eye, since the circuit takes 26,000 years to complete, but astronomers deal with it all the time.

But Shakespeare did get something right in that passage: the stars themselves do move. It’s slow, but it’s there. It’s caused by their orbital motion as they circle the center of the Milky Way. Their velocity can be hundreds of kilometers per second, but that apparent motion is dwarfed to a near standstill by their forbidding distance. Of course, that means that closer stars will appear to move faster than ones farther away, just like trees by the side of the road whiz by as you drive, but distant mountains slide along in a much more stately manner.

It takes decades, sometimes, to see that stellar movement at all — astronomers call it proper motion — but it’s not impossible. Greek amateur astronomer Anthony Ayiomamitis (who has been featured on this blog before here and here) knew that very well, and he was able to prove it. Behold, the unfix’d heavens!

barnards_star_split

These two pictures show the same region of sky, separated in time by six decades. The top, taken in 1950, is from the famous Palomar Sky Survey, a tool still used by astronomers to guide their observations. The marked star is Barnard’s Star, a dinky, dim red bulb a mere 6 light years away — which makes it one of the closest of all the stars in the galaxy.

Barnard was a phenomenal astronomer, and inferred that since it was a red dwarf, for it to be seen at all means it must be close. He kept his eye on it over the years, and was able to measure its apparent speed across the sky. It moves a phenomenal 10 arcseconds per year, which is tiny in normal life, but pretty frakkin’ fast for a star. In 60 years since the Palomar observations, Ayiomamitis was able to capture it in the lower half of that image, where again its position is marked. Note how far it’s moved! In the intervening decades it’s traveled about 10 arcminutes, or about 1/3 the size of the Moon on the sky!

That’s fast. If every star moved that quickly, the constellations would last only a few centuries before being distorted beyond recognition. As it is, we see pretty much the same constellations ancient Sumerians did.

Note that the Palomar image is in black and white; Ayiomamitis took color images and you can see the dull red glow of Barnard’s Runaway Star.

It might help to see the two images superposed; Ayiomamitis did that for me when he alerted me to his observations:

barnards_star1950-2010

Very cool. Note the number of faint stars; Barnard’s star is located in the constellation of Ophiuchus, which is near the galactic center, and is loaded with stars. Imagine trying to find that one faint ember among all those stars, and you start to get a glimpse of how amazing an observer Barnard was. Remember, this was before computers, digital photography, or any of those modern conveniences. He used film — actually, emulsion sprayed on glass plates — guided the telescope by hand, developed the plates, and measured them, again by hand. And he found that star among the millions of others.

In real terms, the star is moving at about 140 km/sec (90 miles/second) relative to the Sun. Its direction is bringing it closer to us, though it’ll never get closer than about 4 light years — slightly closer than Alpha Centauri is to us now. It’ll still be faint; only about twice as bright as it is now, and at the moment you need pretty good binoculars to see it at all! It’s shining at about magnitude 9.5, or 1/16th as bright as the faintest star you can see with your unaided eye. Of course, it won’t slide past us for about another 9000 years, so don’t hold your breath. And even though the age of the star is about 12 billion years, as a red dwarf it hasn’t even reached middle age yet. They last a long, long time. I bet over its life it’s seen far closer passes to stars like the Sun, and will live to see many more.

And finally, back to Shakespeare: even ignoring the Earth’s wobble, he still blew it in that passage from Julius Caesar. The North Star moves too. Of course, its proper motion is pretty small because it’s a long way off, over 400 light years away. Compared to Barnard’s Star, it’s hardly moving. Given that then, I suppose, I can give Shakespeare some credit.

Perhaps the fault lies in ourselves, and not the stars.

Image credit: Anthony Ayiomamitis and the Digitized Sky Survey


Synchronization

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Hi.

We have a unit connected system. In a unit connected system, generator is connected to transformer then to 220kv circuit breaker.

1. The c.b. is called a synchronization breaker? i.e. closed at that particular instant?!

How syncrhonization will be analyzed here?

Circuit Breaker Fail Protection.

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Hi,

A circuit breaker is designed to operate on fault, when the sensed current is above the preset current on fault conditions. How is the circuit breaker fail safe protection system designed? Also, how is autoreclosing made possible?

sks

New Nicaraguan sign language shows how language affects thought | Not Exactly Rocket Science

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NicaraguaOne of the signs for “Nicaragua”. Photo by Ann Serghas

In the 1970s, a group of deaf Nicaraguan schoolchildren invented a new language. The kids were the first to enrol in Nicaragua’s new wave of special education schools. At first, they struggled with the schools’ focus on Spanish and lip-reading, but they found companionship in each other. It was the first time that deaf people from all over the country could gather in large numbers and through their interactions – in the schoolyard and the bus – Nicaraguan Sign Language (NSL) spontaneously came into being.

NSL is not a direct translation of Spanish – it is a language in its own right, complete with its own grammar and vocabulary. Its child inventors created it naturally by combining and adding to gestures that they had used at home. Gradually, the language became more regular, more complex and faster. Ever since, NSL has been a goldmine for scientists, providing an unparalleled opportunity to study the emergence of a new language. And in a new study led by Jennie Pyers from Wellesley College, it even tells us how language shapes our thought.

By studying children who learned NSL at various stages of its development, Pyers has shown that the vocabulary they pick up affects the way they think. Specifically, those who learned NSL before it developed specific gestures for left and right perform more poorly on a spatial awareness test than children who grew up knowing how to sign those terms.

The idea that language affects thought isn’t new. It’s encapsulated by the ‘Sapir-Whorf hypothesis’, which suggests that differences in the languages we speak affect the way we think and behave. Typically, scientists test this link between language and thought by either comparing people who speak different languages, or by watching children as they, and their linguistic skills, develop. But both approaches have problems. Speakers of different languages also vary in many other ways that can affect the way they think, while growing children are also developing in many other aspects of their mental skills, which could confuse any effect of language alone.

But NSL cuts through both of these problems. Here is a language that was learned by successive waves of children whose mental skills were relatively mature, who all came from the same culture, and who all learned the language at the same age.

In most sign languages, signers map the positions of real-world objects using their hands, rather than using words like ‘left’, ‘inside’ or ‘over’. Someone signing a cat on a table would place one hand, representing a cat, over the other, representing the table, with no separate sign for ‘on’. The same works for left and right, with the added rule that usually, the signer represents the scene from their own perspective.

But NSL hasn’t quite got to that stage yet. In the first version developed in the 1970s, the children hadn’t settled on a consistent way of indicating left and right, and the locations of objects in their conversations are fairly ambiguous. The second group of children to expand NSL in the 1980s had more specific conventions for position.

Pyers compared the abilities of people from both groups, now fully grown adults, in two spatial tests. First, she led them into a small room with a single red wall. She hid a token in one corner of the room, blindfolded the children and spun them around until they lost their bearings. When she removed the blindfold, the children had to say where the token was. The second test, like the first, involved hiding a token in the corner of a room, but this time the room was a tabletop model that was rotated while the children were blindfolded.

In both tests, the second group of adults (who learned the more advanced form of NSL) outperformed the first group. Even though their memories and ability to understand the tasks were just as good, the expanded vocabulary of geographical gestures that they learned as children also gave them better spatial abilities well into adulthood.

By comparing the first group of NSL signers to typical children, Pyers also learned something about what’s going on in their heads. Children find the task easy and answer quickly but they often make mistakes. They’ll orient themselves to the geometry of the room, using the long and short walls to tell them where the token is. But they tend to ignore the red wall landmark so when they make mistakes, they usually go for the corner diagonally opposite to the correct one.

The first group of NSL signers were very different. They were more accurate, suggesting that their experience and maturity does at least count for something. Their mistakes are evenly distributed around the three other corners, suggesting that they use neither the landmark nor the room’s geometry to help them. And they took a long time over the test and said that they found it very difficult. They were aware of their own uncertainty, as adults often are, but they simply didn’t have a reliable mental map of the room and its hidden token.

Pyers explains, “The first-cohort signers find these tasks challenging because they do not have the language to encode the relevant aspects of the environment that would help them solve the spatial problem.” She added, “[They] did not have a consistent linguistic means to encode ‘left of’.”

This is a fascinating result, especially since the first group of adults were older and had been signing for a longer time. It’s clear evidence that our spatial reasoning skills depend, to an extent, on consistent spatial language. If we lack the right words, our mental abilities are limited in a way that extra life experience can’t fully compensate for. Even 30 years of navigating through the world won’t do the trick. And they may never catch up, even though the language they invented has advanced – after all, some studies with American Sign Language suggest that people who learn spatial terms later on in life never master them.

This is a subtly different idea than the one espoused by the Sapir-Whorf hypothesis, which suggests that different languages influence how speakers think about their world. By contrast, Pyers’ results focus “on those aspects of human cognition that are dependent on acquiring a language, any language”. She says that the room tasks tap into a set of mental skills that “crucially depends on language and that this relationship between language and spatial cognition should hold true for speakers of all languages”.

The Nicaraguan signers may well reveal more ways in which language fundamentally affects thought, for other aspects of the language besides spatial locations became more complex over time. These include ways of signifying mental states, and Pyers has already shown that as these became more sophisticated, so did the signers’ abilities to understand the fact that other people can hold false beliefs. Meanwhile, Ann Senghas and Molly Flaherty, who worked on the current study, are looking at how the emergence of a counting system in NSL affected the numerical skills of the signers.

The grand idea behind all of these singular observations is that as human language evolved, our mental abilities became increasingly entwined with linguistic devices. Those devices are part and parcel of modern language, and thus modern thought. NSL, being a new language, is the exception that proves the rule – as it developed, so did the abilities of those who learned it, from their skills at visualising objects in space to their capacity for understanding the minds of their peers.

Reference: PNAS http://dx.doi.org/10.1073/pnas.0914044107

More on gestures and language:

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The Scientific Consensus on Climate Change: Stronger and Stronger | The Intersection

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Courtesy of Rick Piltz, I learn of a new paper in the Proceedings of the National Academy of Sciences that powerfully demonstrates just how convinced scientists are that global warming is real and human caused. Indeed, this paper, entitled "Expert Credibility in Climate Change," looks at the relationship between scientific prominence, amount of work published in the field, and acceptance of the scientific consensus. Findings:
(i) 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and
(ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers. Those of us who follow this issue closely won't be surprised--but the results mean that journalists who have given a lot of weight to climate "skeptics" have some 'splaining to do. Essentially, this paper seems to be suggesting that they got the wrong "experts." Incidentally, given how closely this study hits home, I would expect it to be attacked--just as Naomi Oreskes' famous paper "The Scientific Consensus on Climate Change" ...


Bicycle Headset

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Hi, Does anyone know of an internal to external headset adaptor for 1 1/8" threadless headsets? Mine is knackered, and I would prefer to go external just because of they are more reliable and better made. Thanks.

House Gets Firm With NASA Over Data Request

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Letter From House Science & Technology Committee to Charles Bolden Regarding FY 2011 Budget Information

"The failure of NASA to supply Congress with this information hampers our ability to address the future of NASA's human spaceflight program in a timely manner. Simultaneously, the agency is implementing dramatic changes to the Constellation program which are resulting in the loss of thousands of skilled jobs and which will cause unavoidable delays in the development of Ares-I and Orion, should Congress decide not to terminate those programs. Since NASA has failed to provide the Committee with any detailed supporting materials with which Congress can judge the proposed human spaceflight plan, Congress must insist upon the production of all materials NASA relied upon in formulating its proposal."

Power Generation Dynamo Driven Only by Magnets

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With green energy being subject of every day life, I am looking for a DYNAMO FOR POWER GENERATION DRIVEN ONLY BY POWERFUL MAGNETS that can supply power to the main power grid in a town, city.......

Does such a product exist? If yea can some one help me find the manufacturers / suppliers?

Anchoring a Billboard Frame in Concrete Columns

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For reasons best known to him, the Head of my daughter's school wants to build a permanent framework of steel pipes, extending the full length of the school's street frontage, to which banners, streamers and billboards can be attached. Per a proposal submitted by a local architect, the uprights of t