Elephants are social creatures. They need the presence of other
elephants. Starting in 2016, the Association of Zoos and Aquariums will
require room for three elephants if a zoo wants to retain AZA accreditation.
There are 20 or so "two-elephant zoos" in the United States. One such is
the Sedgwick County Zoo in Wichita, where African elephants
Cinda and Stephanie have been together for 40 years. Unless the zoo is
expanded, they would have to move, possibly getting split up.
"They are like sisters, they came here when they were five feet tall and
grew up together," said Mike Quick, curator of mammals at the Sedgwick
County Zoo. "What would happen if one died? It would be traumatic."
A recent turn for the worse:
"Sedgwick County Zoo is sad to announce that Cinda, African elephant,
passed away the morning of November 5, 2014. The Sedgwick County Zoo
will continue to work on raising funds for the construction of the
Elephants of the Zambezi River Valley habitat, set to open in May of
2016. There is approximately $900,000 left to raise in the public campaign."
~~~~~
The situation in Topeka is not much better. The Topeka Zoo also has two
very aged elephants: Sunda, 54, an Asian elephant, and Tembo, 44, an
African elephant, inhabiting cramped quarters. Most places keep Asian
and African elephants apart, so if they were retired to a sanctuary,
these longstanding friends would probably have to be split up.
An expanded facility has been discussed, but even if approved, construction is projected to take five years, exceeding the animals' expected
remaining lifetime.
~~~~~
Reproduction requires, of course, bull elephants, but keeping bull
elephants is much more difficult. Much of routine elephant care is
hands-on: daily washing and scrubbing, foot care, etc. Cow elephants
become tame and acclimated to this. They learn to obey commands, and
even put on shows for the visitors. As a result, the zoo man in charge
of them is called an elephant "trainer".
Bull elephants, on the other hand, remain wild and dangerous, and must
be handled like any other wild animal, always separated from their
caretaker by heavy bars.
Still, there is at least some good news:
The Portland Zoo has a new 300 lb baby elephant. The mother is a
permanent resident of the zoo, while the father was obtained on loan
from an elephant rental company, "Have Trunk Will Travel".
~~~~~
Q. How can you tell you have two elephants in your refrigerator?
A. You can hear them giggling when the light goes out.
Tuesday, April 28, 2015
Thursday, April 9, 2015
Three Things About Running
[Original, but the style imitates "Threes", by Mercedes Lackey]
Suburban Kansas City, early morning clear and cold,
A troupe of cars approaches as the sunrise turns to gold.
They come from all directions and in front of us converge.
They slowly fill the parking lot and passengers emerge.
Three things you can count on -- that the sun will always rise,
That someone else is faster, and your shoes will come untied.
These soldiers make no notice of the wind and ice and cold.
Their stride is firm and certain, and their countenances bold,
Each person has a smiling face, their talk is full of jest,
But each person looks determined, and prepared to do his best.
Three things never shrink from -- a cold wind upon your face,
An early morning wakeup, and the challenge of a race.
Each person walking toward us from the cars is brightly dressed,
With running shoes, and numbers safety-pinned upon their chest,
Some in shorts and singlets, though there's frost upon the ground,
Their thoughts are clearly elsewhere as the racers gather round.
Three things to get used to -- expensive running shoes,
Grown men wearing numbers, and the pounds you cannot lose.
Speakers have been set up, lively music starts to play,
People jogging to and fro, we'll soon be underway.
We gather at the starting line, the music becomes soft.
The whistle blows, the race clock starts, and suddenly we're off.
Three things to remember -- never jump the starting gun,
Never trip the guy behind you, never wonder where to run.
The first mile is completed, but you still have two in store,
The second mile is siimilar, you've run this race before.
The third mile makes you climb back where the other miles led down,
But the last leg to the finish lifts your feet up off the ground.
Three things to beware of -- running trails that lead nowhere,
Empty cups along the race course, guys who yell you're almost there.
The Finish Line is now in view, you hear the crowd's applause
Announcing the arrival of the runners as they cross.
The photog takes a picture, while the race clock shows your time.
You'll get a rousing cheer from those who beat you to the line!
Three things trust above all else -- the race director's fair,
A race course that's been certified, the timing chip you wear.
Suburban Kansas City, early morning clear and cold,
A troupe of cars approaches as the sunrise turns to gold.
They come from all directions and in front of us converge.
They slowly fill the parking lot and passengers emerge.
Three things you can count on -- that the sun will always rise,
That someone else is faster, and your shoes will come untied.
These soldiers make no notice of the wind and ice and cold.
Their stride is firm and certain, and their countenances bold,
Each person has a smiling face, their talk is full of jest,
But each person looks determined, and prepared to do his best.
Three things never shrink from -- a cold wind upon your face,
An early morning wakeup, and the challenge of a race.
Each person walking toward us from the cars is brightly dressed,
With running shoes, and numbers safety-pinned upon their chest,
Some in shorts and singlets, though there's frost upon the ground,
Their thoughts are clearly elsewhere as the racers gather round.
Three things to get used to -- expensive running shoes,
Grown men wearing numbers, and the pounds you cannot lose.
Speakers have been set up, lively music starts to play,
People jogging to and fro, we'll soon be underway.
We gather at the starting line, the music becomes soft.
The whistle blows, the race clock starts, and suddenly we're off.
Three things to remember -- never jump the starting gun,
Never trip the guy behind you, never wonder where to run.
The first mile is completed, but you still have two in store,
The second mile is siimilar, you've run this race before.
The third mile makes you climb back where the other miles led down,
But the last leg to the finish lifts your feet up off the ground.
Three things to beware of -- running trails that lead nowhere,
Empty cups along the race course, guys who yell you're almost there.
The Finish Line is now in view, you hear the crowd's applause
Announcing the arrival of the runners as they cross.
The photog takes a picture, while the race clock shows your time.
You'll get a rousing cheer from those who beat you to the line!
Three things trust above all else -- the race director's fair,
A race course that's been certified, the timing chip you wear.
Wednesday, February 2, 2011
LHC Splice Repair
Let's see if I can summarize the situation with the LHC splices.
The LHC has three main power circuits: one for the dipole magnets ("RB" = bending) and two for the quadrupole magnets ("RQF" = focusing and "RQD" = defocusing) These are known as the 13 kA circuits, although this is somewhat of a misnomer. With the LHC at full power (7 TeV) they carry 11.8 kA and produce an 8.33 T field. However the design limit of the magnets is higher: 9.0 T, corresponding to a current of 12.8 kA.
The superconducting cables are Nb-Ti Rutherford cables, the joints between them soldered with high-temperature silver solder (96 percent tin, 4 percent silver). Normal joint resistance varies considerably with temperature, being about 10 μΩ warm, 300 pΩ cold. The cables are supported by a copper bus stabilizer with a cross-section of 280 mm2. Each joint is compressed between a 12 cm copper wedge and a 15.5 cm copper U-profile, together referred to as a joint stabilizer.
In the LHC there are a total of 24,000 splices - 10,000 interconnect splices and 14,000 magnet splices. If a quench happens (sudden loss of superconductivity) the current must temporarily pass through the surrounding copper. Magnet splices are protected by diodes, but interconnect splices are not, and the copper stabilizer must be designed to handle the full current for up to 100 sec.
The magnets have been commissioned to 5.5 TeV. The Sept 19, 2008 incident occurred during the last phase of the 5.5 TeV commissioning, and is believed to have been caused by a 200 nΩ interconnect, which is 1000 times too large.
Several types of problem have been identified:
- Anomalously high contact resistance between the superconducting cables (tens of nΩ at 1.9K).
- Lack of continuity between the superconductor and the stabilizer, or between parts of the stabilizer. This can be due to a joint which was poorly soldered or even missing solder.
The most dangerous situation is when a cable-stabilizer defect and a stabilizer-stablizer defect both occur at the same joint.
Cable-to-cable resistances at cold have been measured with excellent accuracy, and are not considered to be a problem. The worst joints are 2.7 nΩ for RB and 3.2 nΩ for RQ, and both of these are acceptable. The new Quench Protection System (nQPS) continuously monitors these resistances.
Measurement of resistances involving the copper stabilizer requires a warmup. The four sectors (S12, S34, S56 and S67) that were warm during 2009 have been thoroughly surveyed, segment by segment, using a "Biddle" hand-held nanovoltmeter (named for the manufacturer). One sector (S45) has been done at both 80 K and 300 K for comparison's sake, while the remaining three (S23, S78 and S81) have not been measured at all. Such measurements are sufficiently accurate for the RB circuit but not the RQ.
The term R16 refers to an individual joint resistance measurement at warm of the 16-cm long stabilizer. Only a sampling of these have been done. Typical R16 values are 12 μΩ for RB and 19 μΩ for RQ, but others have been found that range up to 60 μΩ. Also, some splices had acceptable R16 values but nevertheless upon visual inspection were found to be physically defective.
Complete repair during the "long shutdown" will involve a full warmup, then location and resoldering of each defective joint. It is expected that 15 to 20 percent of the joints will need repair. In view of the fact that even good joints can degrade over time due to electromagnetic and thermal cycling, the installation of an additional copper shunt on *every one* of the 10,000 interconnect splices will be required. This shunt will be designed to withstand the full current for 100 secs. So as not to affect the existing silver solder, it will be soldered in place with eutectic 60-40 tin-lead solder, and will include mechanical clamps that will hold the splice together in the event of a failure.
In the meantime, what can be done to further understand the problem? Without opening the individual joints, measurements can only be made at certain externally accessible voltage taps. Thus, resistance can only be measured for busbar segments spannning several joints: 2 or 3 joints for RB, and 8 joints for RQ. The nQPS system monitors these taps, and can be used to measure segment resistances at cold to within 1 nΩ.
There are several possibilities:
1) Warm up the 3 remaining sectors, measure the busbar resistances, open and repair the bad ones, and cool down again. (No comprehensive visual inspection or shunt installation.) This would serve to reduce the highest excess resistance from 90 μΩ to 60 μΩ, but only for the RB bus. (Knowledge of the RQ bus is not good enough.) Time required: more than 3 months, which is too long.
2) Measure the RRR at low current and partial warmup (15 - 35 K). Time required: 2 weeks. The residual resistivity ratio (RRR) is the ratio of the resistivity of a segment at warm vs just above the superconducting transition (9.6 K) The RRR of a factory-fresh cable is 70-100, but it increases when subjected to the soldering process. A well-soldered (and therefore well-heated) joint will have RRR > 150, but for a defective one the RRR may be less. Present operation assumes an RRR of 100. Certification of a higher RRR for the entire machine would mean an increased safety margin, or possibly allow operation at higher energy.
3) The "thermal amplifier" approach. Apply a 3 kA current pulse for 10 secs. This will selectively warm up the bad joints. Then use a low current in conjunction with the nQPS to identify the areas of increased resistance. This would find all splices > 50 μΩ. Time required: 1 month, short enough that this test could be scheduled during the 2011/2012 year-end stop.
The LHC has three main power circuits: one for the dipole magnets ("RB" = bending) and two for the quadrupole magnets ("RQF" = focusing and "RQD" = defocusing) These are known as the 13 kA circuits, although this is somewhat of a misnomer. With the LHC at full power (7 TeV) they carry 11.8 kA and produce an 8.33 T field. However the design limit of the magnets is higher: 9.0 T, corresponding to a current of 12.8 kA.
The superconducting cables are Nb-Ti Rutherford cables, the joints between them soldered with high-temperature silver solder (96 percent tin, 4 percent silver). Normal joint resistance varies considerably with temperature, being about 10 μΩ warm, 300 pΩ cold. The cables are supported by a copper bus stabilizer with a cross-section of 280 mm2. Each joint is compressed between a 12 cm copper wedge and a 15.5 cm copper U-profile, together referred to as a joint stabilizer.
In the LHC there are a total of 24,000 splices - 10,000 interconnect splices and 14,000 magnet splices. If a quench happens (sudden loss of superconductivity) the current must temporarily pass through the surrounding copper. Magnet splices are protected by diodes, but interconnect splices are not, and the copper stabilizer must be designed to handle the full current for up to 100 sec.
The magnets have been commissioned to 5.5 TeV. The Sept 19, 2008 incident occurred during the last phase of the 5.5 TeV commissioning, and is believed to have been caused by a 200 nΩ interconnect, which is 1000 times too large.
Several types of problem have been identified:
- Anomalously high contact resistance between the superconducting cables (tens of nΩ at 1.9K).
- Lack of continuity between the superconductor and the stabilizer, or between parts of the stabilizer. This can be due to a joint which was poorly soldered or even missing solder.
The most dangerous situation is when a cable-stabilizer defect and a stabilizer-stablizer defect both occur at the same joint.
Cable-to-cable resistances at cold have been measured with excellent accuracy, and are not considered to be a problem. The worst joints are 2.7 nΩ for RB and 3.2 nΩ for RQ, and both of these are acceptable. The new Quench Protection System (nQPS) continuously monitors these resistances.
Measurement of resistances involving the copper stabilizer requires a warmup. The four sectors (S12, S34, S56 and S67) that were warm during 2009 have been thoroughly surveyed, segment by segment, using a "Biddle" hand-held nanovoltmeter (named for the manufacturer). One sector (S45) has been done at both 80 K and 300 K for comparison's sake, while the remaining three (S23, S78 and S81) have not been measured at all. Such measurements are sufficiently accurate for the RB circuit but not the RQ.
The term R16 refers to an individual joint resistance measurement at warm of the 16-cm long stabilizer. Only a sampling of these have been done. Typical R16 values are 12 μΩ for RB and 19 μΩ for RQ, but others have been found that range up to 60 μΩ. Also, some splices had acceptable R16 values but nevertheless upon visual inspection were found to be physically defective.
Complete repair during the "long shutdown" will involve a full warmup, then location and resoldering of each defective joint. It is expected that 15 to 20 percent of the joints will need repair. In view of the fact that even good joints can degrade over time due to electromagnetic and thermal cycling, the installation of an additional copper shunt on *every one* of the 10,000 interconnect splices will be required. This shunt will be designed to withstand the full current for 100 secs. So as not to affect the existing silver solder, it will be soldered in place with eutectic 60-40 tin-lead solder, and will include mechanical clamps that will hold the splice together in the event of a failure.
In the meantime, what can be done to further understand the problem? Without opening the individual joints, measurements can only be made at certain externally accessible voltage taps. Thus, resistance can only be measured for busbar segments spannning several joints: 2 or 3 joints for RB, and 8 joints for RQ. The nQPS system monitors these taps, and can be used to measure segment resistances at cold to within 1 nΩ.
There are several possibilities:
1) Warm up the 3 remaining sectors, measure the busbar resistances, open and repair the bad ones, and cool down again. (No comprehensive visual inspection or shunt installation.) This would serve to reduce the highest excess resistance from 90 μΩ to 60 μΩ, but only for the RB bus. (Knowledge of the RQ bus is not good enough.) Time required: more than 3 months, which is too long.
2) Measure the RRR at low current and partial warmup (15 - 35 K). Time required: 2 weeks. The residual resistivity ratio (RRR) is the ratio of the resistivity of a segment at warm vs just above the superconducting transition (9.6 K) The RRR of a factory-fresh cable is 70-100, but it increases when subjected to the soldering process. A well-soldered (and therefore well-heated) joint will have RRR > 150, but for a defective one the RRR may be less. Present operation assumes an RRR of 100. Certification of a higher RRR for the entire machine would mean an increased safety margin, or possibly allow operation at higher energy.
3) The "thermal amplifier" approach. Apply a 3 kA current pulse for 10 secs. This will selectively warm up the bad joints. Then use a low current in conjunction with the nQPS to identify the areas of increased resistance. This would find all splices > 50 μΩ. Time required: 1 month, short enough that this test could be scheduled during the 2011/2012 year-end stop.
Thursday, June 17, 2010
Saturday, June 12, 2010
Thursday, June 3, 2010
Robert Heinlein, the well-known science fiction author, was a quite outspoken and opinionated person. Especially he believed in independence, self-reliance and rationality, and demanded it of others. Here's a quote:
"We define thinking as integrating data and arriving at correct answers. Look around you. Most people do that stunt just well enough to get to the corner store and back without breaking a leg. If the average man thinks at all, he does silly things like generalizing from a single datum. He uses one-valued logic. If he is exceptionally bright, he may use two-valued, 'either-or' logic to arrive at his wrong answers. If he is hungry, hurt, or personally interested in the answer, he can't use any sort of logic and will discard an observed fact as blithely as he will stake his life on a piece of wishful thinking. He uses the technical miracles created by superior men without wonder or surprise, as a kitten accepts a bowl of milk. Far from aspiring to higher reasoning, he is not even aware that higher reasoning exists. He classes his own mental process as being of the same sort as the genius of an Einstein. Man is not a rational animal; he is a rationalizing animal.
"For explanations of a universe that confuses him he seizes onto numerology, astrology, hysterical religions, and other fancy ways to go crazy. Having accepted such glorified nonsense, facts make no impression on him, if even at the cost of his own life. One of the hardest things to believe is the abysmal depth of human stupidity."
Tuesday, June 1, 2010
WARNING - Earworm Alert!
According to those who spend their time studying such things, some 98 to 99 percent of the population has, at some point, been 'infected' with a song they just can't seem to shake off. In most cases, earworms will disappear after a few minutes. But in some cases, earworms can last hours or even days.
French-speaking Internet users were asked to rank 100 pop songs according to their ability to be compulsively repeated within one's mind. The songs voted top five were: 'Singin' in the Rain' (Gene Kelly), 'Life Is Live' (Opus), 'Don't Worry, Be Happy' (Bobby McFerrin), 'I Will Survive' (Gloria Gaynor).
And, IN FIRST PLACE, the number one earworm for those who speak French is: 'Ça fait rire les oiseaux.'
(Ok, so you probably weren't thinking of that one, were you.)
But with that introduction, if you still DARE to listen to it, here it is -- the number one earworm!
http://www.youtube.com/watch?v=EiqP1MrU6D0
Maybe French-speaking people are just... different.
--
Over the weekend I posed this question to my immediate family, with striking results. Potential earworms we agreed upon:
o It's a Small World After All
o Frosty The Snowman
o any song from Mary Poppins
Reactions to these were like, "Yeah, I guess so, sometimes, sure."
(Due to generational differences, I thought of some songs they had never heard of, and vice versa.)
But then I suggested THIS one, and the reactions were, "Aggghh, no!! Not that one! Stop playing with my mind!!"
http://video.google.com/videoplay?docid=-7173367298729056137
French-speaking Internet users were asked to rank 100 pop songs according to their ability to be compulsively repeated within one's mind. The songs voted top five were: 'Singin' in the Rain' (Gene Kelly), 'Life Is Live' (Opus), 'Don't Worry, Be Happy' (Bobby McFerrin), 'I Will Survive' (Gloria Gaynor).
And, IN FIRST PLACE, the number one earworm for those who speak French is: 'Ça fait rire les oiseaux.'
(Ok, so you probably weren't thinking of that one, were you.)
But with that introduction, if you still DARE to listen to it, here it is -- the number one earworm!
http://www.youtube.com/watch?v=EiqP1MrU6D0
Maybe French-speaking people are just... different.
--
Over the weekend I posed this question to my immediate family, with striking results. Potential earworms we agreed upon:
o It's a Small World After All
o Frosty The Snowman
o any song from Mary Poppins
Reactions to these were like, "Yeah, I guess so, sometimes, sure."
(Due to generational differences, I thought of some songs they had never heard of, and vice versa.)
But then I suggested THIS one, and the reactions were, "Aggghh, no!! Not that one! Stop playing with my mind!!"
http://video.google.com/videoplay?docid=-7173367298729056137
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