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Wednesday Open Thread

by afew Wed Mar 27th, 2013 at 11:50:38 AM EST

Midweek threadies


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Not a new breakfast cereal.
by afew (afew(a in a circle)eurotrib_dot_com) on Wed Mar 27th, 2013 at 11:51:18 AM EST
It's a floor wax and a dessert topping!

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre
by ATinNM on Wed Mar 27th, 2013 at 12:27:47 PM EST
[ Parent ]
Get yours today!
by afew (afew(a in a circle)eurotrib_dot_com) on Wed Mar 27th, 2013 at 12:29:09 PM EST
[ Parent ]
MercoPress: Argentina's nationalized energy company YPF on Tuesday signed a memorandum of understanding with the local subsidiary of the US Dow Chemical to develop the shale gas deposits in the southern Nequen province.


"Beware of the man who does not talk, and the dog that does not bark." Cheyenne
by maracatu on Wed Mar 27th, 2013 at 12:57:38 PM EST
Good thing too!
by afew (afew(a in a circle)eurotrib_dot_com) on Thu Mar 28th, 2013 at 04:10:32 AM EST
[ Parent ]
Japan has found deposits of rare earths:

Japan has discovered an "astronomically" high level of rare earth deposits about 5.8 kilometers under the Pacific Ocean's surface, near Minami Torishima island south-east of Tokyo. The discovered rare minerals, which include drysprosium, are used in the production of high technology equipment such as smartphones, hard disks or catalytic converters.

Rare earths aren't all that rare.  Find them all over the place, including sea water (IIRC.)  They are rarely found in concentrations economically viable to mine.

Rare earths have been the center of a foo-foo over the last couple of years.  China is, currently, the global supplier and they've been using their control of supply to "invite" factories to move there by doubling the export price wrt domestic price.  US has been party to a protest at the WTO.

The fact the US has export controls on high-tech products isn't brought into the discussion because Communism Terrorism!

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre

by ATinNM on Wed Mar 27th, 2013 at 01:20:45 PM EST
Hello everyone. What happened to the recommend diary button/link? I'm pretty sure I already recommended diaries after the new interface was set up, but today I can't find it. Is this a bug? Or me needing new glasses?

luis_de_sousa@mastodon.social
by Luis de Sousa (luis[dot]de[dot]sousa[at]protonmail[dot]ch) on Wed Mar 27th, 2013 at 02:14:37 PM EST
If the diary is posted as a story (direct-to-frontpage) it cannot be recommended.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Wed Mar 27th, 2013 at 02:19:45 PM EST
[ Parent ]
We had a discussion regarding local and macroscale wake effects in Cyprus 5. that discussion's in the past, but thought it important to give a visual of what wake effects mean.

Vestas 2MW turbines at Horns Reef (Horns Rev) from 2004

"Life shrinks or expands in proportion to one's courage." - Anaïs Nin

by Crazy Horse on Wed Mar 27th, 2013 at 02:21:04 PM EST
Fab photo

keep to the Fen Causeway
by Helen (lareinagal at yahoo dot co dot uk) on Wed Mar 27th, 2013 at 02:28:11 PM EST
[ Parent ]
you can see the turbulence in the wakes like in a smoke tunnel

and the fact that there isn't much interaction between rows.

by stevesim on Wed Mar 27th, 2013 at 02:41:12 PM EST
[ Parent ]
The photo is a wonderful visualization of the turbulence associated with wind generators. Is there data on the output power of successive generators back from the first? That, along with wind speed, would be a useful way to quantify wake effects. Also, might it be possible to maintain an angle of attack into the wind by the generator heads? If so that would allow the wake effect to be distributed more widely through the array.

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Wed Mar 27th, 2013 at 02:39:42 PM EST
[ Parent ]
no, because the turbulence in the wake, maintaining an angle of attack is rather difficult

however, the wake does cause efficiency -  as exemplified in cars driving in the wake of a car in front of theirs to minimize drag and wind resistance

by stevesim on Wed Mar 27th, 2013 at 02:44:52 PM EST
[ Parent ]
I would think the race car analogy would be more an example of the detrimental effects of wake turbulence. It takes power to push the car through the air and that power, IIRC, is linear. In the case of race cars the following cars require less power for the same speed as the lead car does a disproportionate amount of the work of moving the air around the vehicle, setting up the wake in which others can follow. In the windmill example the blades use the wind energy to generate the lift to make them turn. Less total wind energy would be available to turn the second and third sets of blades due to losses to turbulence, rather like a competition yacht spoiling the wind of a competitor by turning in front of it.

What my brilliant possibility requires is either the ability to dither the wind direction back and forth by a few degrees or to rotate the array at a similar rate and I cannot imagine a feasible way to do that. I wrote before I thought.  

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."

by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Wed Mar 27th, 2013 at 03:34:54 PM EST
[ Parent ]
On reflection the 'angle of attack' seems improbable. :-)

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Wed Mar 27th, 2013 at 02:44:57 PM EST
[ Parent ]
I just reviewed my basic aerodynamics.

Reynolds number is the ratio of inertial forces to viscous forces

Laminar flow has a Reynolds number below 2000

Turbulent flow usually is somewhere above that because thtere is a transition state, it is not exactly at 2000

The Coefficient of Lift is defined as the lift force over the inertial forces so if the inertial forces are high (as in turbulent flow), the Coefficient of Lift is larger

The Coefficient of Drag on the other hand, is defned as the forces of drag over the viscous forces, so a lower Reynolds number (in laminar flow) would have more viscous forces and a higher Coefficient of Drag.

Therefore, turbulent flow should provide a more efficient ratio of Lift to Drag.

by stevesim on Wed Mar 27th, 2013 at 03:16:15 PM EST
[ Parent ]

Is there data on the output power of successive generators back from the first?

Yes, there is, but the results are slightly counter-intuitive. From memory, the highest losses are in the second row, and decrease beyond that.

Distance between rows is typically longest in the prevailing wind conditions, not unsurprisingly - typically 7-8 rotor diameters.

Wind power

by Jerome a Paris (etg@eurotrib.com) on Wed Mar 27th, 2013 at 04:49:51 PM EST
[ Parent ]
Counter-intuitive? I would expect the second row, which is the first to encounter wake turbulence, to have the biggest drop and then for drops to increase slowly WRT the first row as one moves back in the array. The first row is the only one not to encounter wakes. What is considered the maximum acceptable drop allowed for the last row of an array? Any rule of thumb?

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Wed Mar 27th, 2013 at 04:59:56 PM EST
[ Parent ]
I just did some quick reading on this.

The drop in efficiency has to do with the wind speed not the effect of turbulence.  

by stevesim on Wed Mar 27th, 2013 at 05:20:07 PM EST
[ Parent ]
I suspect that the drop in wind speed IS the result of turbulence. If energy is extracted by the windmill the total energy of the moving air has to decrease somehow, according to conservation of energy and entropy has to increase. The increased entropy is likely what we see visualized in part. That would be the condensation of water previously present as water vapor as a result of a pressure transient in the vicinity of the blade.

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Wed Mar 27th, 2013 at 08:51:48 PM EST
[ Parent ]
This recent article seems relevant
by mustakissa on Tue Apr 2nd, 2013 at 04:30:48 PM EST
[ Parent ]
Guardian - Neil Clark - Search and rescue sell-off reveals a coalition obsessed with privatisation

Why is the coalition so obsessed with privatisation? It's not as if the sell-off of our railways, our utilities and our infrastructure has been such a great success. We have by far and away the highest rail fares in Europe and spiralling gas, electricity and water charges. It's not as if privatisation is popular and a vote-winner either. The public, whether Tory, Labour or Lib Dem voters, have had enough of it. Polls show big majorities in favour of renationalisation of water and the railways.

Supporters of privatisation say it's a way of saving taxpayers money - but it is actually a drain on the public purse. Our privatised railways receive substantially more in subsidies than British Rail did. Then there's the massive costs involved in privatising a publicly owned enterprise: one study has calculated the cost of rail privatisation as "at least £5bn", and £39.5m alone was paid out in fees to banks.
[....]
By continuing with privatisation the government is showing us that it's more committed to putting the interests of capital - and its backers in the City of London - before the interests of the majority of the electorate. The sad truth is that in the coalition Britain of 2013, it's capital that calls all the shots - and so we get policies that capital wants, regardless of public opinion. That means a privatised Royal Mail, plans for a privatised road network, an NHS opened up to private companies, and a US company taking over search and rescue.



keep to the Fen Causeway
by Helen (lareinagal at yahoo dot co dot uk) on Wed Mar 27th, 2013 at 02:27:16 PM EST
i think the corruption is equal in public or private, as the fat gvt contracts go to buddies-in-bizniz.

not only, i suspect there's much lucre in the cracks during the transition from one to the other, making the operation profitable both ways. run it into the ground nationalised, then promise privatisation will cure the problem, then.... well we should know by now how the story continues...


'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty

by melo (melometa4(at)gmail.com) on Thu Mar 28th, 2013 at 01:40:15 PM EST
[ Parent ]
Although it probably doesn't matter to anybody otside the UK, today is the 50th anniversary of the publication of the Beeching report on the destruction rationalisation of British Railways.

Many blame Beeching alone, but it's worth pointing out that he merely faithfully fulfilled the brief handed to him by the Minster of Transport, Ernest Marples, a man who earned his money s a senior Director of many companies with interests as diverse as road building and road freight transport.

keep to the Fen Causeway

by Helen (lareinagal at yahoo dot co dot uk) on Wed Mar 27th, 2013 at 02:32:36 PM EST
I wonder if they require any of the profits to be reinvested in the UK. Otherwise the likely substantial profits will just add to the current account deficit. Do they figure no one outside of government or industry will be bright enough to notice or that they will not be taken Seriously?

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Wed Mar 27th, 2013 at 05:03:05 PM EST
[ Parent ]
No, 50 years ago nobody ever questioned such things, Ministers were supposed to be high minded working for the benefit of the nation. Who could have imagined such a thing ?

He retired in 74 and fled Britain early in 75 when the tax authorities asked about the 30 years worth of back taxes he owed. Sadly he'd managed to smuggle most of his assets abroad and he died in France 10 years later living in luxury.

keep to the Fen Causeway

by Helen (lareinagal at yahoo dot co dot uk) on Wed Mar 27th, 2013 at 05:12:01 PM EST
[ Parent ]
I was talking about the search and rescue contract just let, given this context: Britain's current account deficit at worst level since 1989. The UK has its own currency and can always pay with it for services obtained from UK residents. And the US corporation that holds the search and rescue operation contract could agree to keep their profits in the UK, by, for example, purchasing UK real estate, or not.

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Wed Mar 27th, 2013 at 10:19:54 PM EST
[ Parent ]
Good grief, that would be interfering with the free movement of capital. No self-respecting conservative govt would do that

keep to the Fen Causeway
by Helen (lareinagal at yahoo dot co dot uk) on Thu Mar 28th, 2013 at 03:49:47 AM EST
[ Parent ]
And apparently no other party will criticize them for running up the trade deficit on behalf of the looters.

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Thu Mar 28th, 2013 at 01:08:14 PM EST
[ Parent ]
ARGeezer:
running up the trade deficit on behalf of the looters.

ARG, that's their job description.

you know, front centre on the Secret Mission Statement.


'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty

by melo (melometa4(at)gmail.com) on Thu Mar 28th, 2013 at 01:43:15 PM EST
[ Parent ]
I've just realised that this BBC report on the subject features a lot of engine classes that had been withdrawn from service (GWR King and LNER Thompson A1 at least) before the report was published

keep to the Fen Causeway
by Helen (lareinagal at yahoo dot co dot uk) on Thu Mar 28th, 2013 at 05:00:03 AM EST
[ Parent ]
Michael Gove's parents summoned to ATL annual conference

Michael Gove's parents have been summoned to the Association of Teachers and Lecturers annual conference to discuss the unruly attitude of the disruptive education secretary.

Mr Gove has angered teachers over the past year with his behaviour, and they have unanimously decided that drastic steps need to be taken.

"If he wants to mess about in his own time then that's fine," said one exasperated teacher.



Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Wed Mar 27th, 2013 at 06:40:17 PM EST
by gk (gk (gk quattro due due sette @gmail.com)) on Thu Mar 28th, 2013 at 03:30:01 AM EST
they do it out of respect y'know

keep to the Fen Causeway
by Helen (lareinagal at yahoo dot co dot uk) on Thu Mar 28th, 2013 at 03:48:49 AM EST
[ Parent ]
This recent article seems relevant.
by mustakissa on Tue Apr 2nd, 2013 at 04:28:59 PM EST


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