Alan Robinson
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Posts posted by Alan Robinson
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Excuse my ignorance on this with what is no doubt a stupid question but how do they get around this problem with icebreakers? In the attached the small ship on the left is Russian with an icebreaker bow.
You might want to google Izod testing or Charpy Vee testing for a full description of notch toughness.
Essentially the cold exterior structure of icebreakers is made of steel that has been specially produced.
The molecular structure of steel is crystaline, and the smaller the crystals, the more the macro material resists the propagation of cracks. The size of the crystals depends on how long the material is held above a critical temperature, which in steel's case is above 550 degrees C. If the material is held at these high temperatures for any duration, the crystals begin to grow and merge, resulting in a weaker material.
The point is that in order to roll steel into the shapes we need, it has to be above this critical temperature; and for normal applications that is fine, and the material is quite suitable. However, for cold temperature applications, these rolled steel products must be re-heated after forming to above the critical temperature and allowed to cool in still air. This is called normalizing, and it produces a fine-grained structure that only becomes brittle at significantly lower temperatures than ordinary structural steel. Naturally, normalized steel is somewhat more expensive than standard structural steels.
You might recall some years ago that there was a serious oil leak from the trans-Alaska oil pipeline. I had my suspicions that perhaps to save cash, the pipeline was in sections made of standard structural steel, and it is not in the realms of fantasy that some maintenance fitter had given the huge pipe a smack with a hammer, causing a crack, and consequently a big bit to fall out allowing oil to gush away. This is only a supposition you understand.
Regarding the Titanic, the builders were not culpable, just ignorant, because these characteristics of steel were poorly understood at the time. Nonetheless, it wasn't a good advert for British shipbuilding that Titanic was built of doubtful materials, and for that reason the circumstance is never discussed.
I might add that cracking was also a very serious problem during WW2 with American built ships, which were fully welded, as opposed to our old fashioned rivet structure. Cracks propagated right through the welded structure, while with rivets, the crack does not pass over a plate edge of course.
Even recently, cracking was the cause of a sinking in the English Channel; everyone remembers the MSC Napoli, which in my view was very shoddily designed and built.
Here is a cracked US Liberty ship....
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Sadly Dr. Zbigniew Jaworowski died unexpectedly on November 12th; although a multi-disciplined scientist he was perhaps best known in the climate world for his work on historical CO2 levels. Here is his last published interview from earlier this year:
I have to say that an 82 year-old person of his undoubted academic standing has no need to perpetuate lies right up to his death. If we can say nothing else of Jaworowski, his criticisms of the AGW theory were heartfelt; and despite petty webistes trying to smear Jaworowski's reputation, my view is that he was never proven wrong, just ignored because of money.
Jaworowski's death is a setback for modern climate science.
The energy companies have years of reaping vast rewards and profits, clearly do little or nothing to invest in the future, now we're finally beginning to face up to a future of dwindling fossil fuel supplies and the need to develop alternatives, and we all have to pay for their short-sighted profligacy.
Yes, but I am actually interested to see as North Sea industrial sites cease to produce, to what extent the corporations respect and live up to the agreements made when they were allowed to extract these natural resources in the first place, decades ago; namely clean up after themselves to the extent nobody could see on the sea bed they had been there.
I am pretty much convinced that the floor of the North Sea soon looks like a junk-yard. Are we really to believe that pipelines will be taken up again? That huge concrete blocks will be removed?
It is all very well people telling me that nobody can see the floor of the North Sea, so what does it matter. But the fact is it does matter. Shoddy sealing of wells can lead to pollution, and obstacles on the sea bed can cost fishermen their lives. In any case, why should people be let off meeting the very obligations they agreed to years ago, now they have reaped the profits they wanted?
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I've mentioned this before but water is a very strange and complicated substance.
Supercool
Utah chemists: Water doesn't have to freeze until minus 55 Fahrenheit
SALT LAKE CITY -- We drink water, bathe in it and we are made mostly of water, yet the common substance poses major mysteries. Now, University of Utah chemists may have solved one enigma by showing how cold water can get before it absolutely must freeze: 55 degrees below zero Fahrenheit.
That's 87 degrees Fahrenheit colder than what most people consider the freezing point of water, namely, 32 F.
Supercooled liquid water must become ice at minus 55 F not just because of the extreme cold, but because the molecular structure of water changes physically to form tetrahedron shapes, with each water molecule loosely bonded to four others, according to the new study by chemists Valeria Molinero and Emily Moore.
It is good to see science making more mundane progress than all this metaphysical cosmology and speed of light ideas WS.
Supercooled water properties do not surprise me. Steel, which pretty much all iron, has some funny properties of which people are generally unaware. One is that when heated to above approximately 600 degrees C it is no longer magnetic. The transition is rather sudden. There is also a sudden transition of steel's properties at temperatures just below 0 degrees C, though this can be modified by alloying and heat treatment; but the material suddenly becomes brittle rather than ductile. Steel cooled to -25 degrees C breaks like glass when struck with a hammer. It was this property that had catastrophic consequences for s/s Titanic. The iceberg impact must have caused much cracking of the ship's hull rather than just bending the plates.
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In the BBC news this evening;
I cannot conceive the poor quality of this report, what on earth is the message?
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Maybe it's time to renounce my Perdita views?
Just out of interest GW, which Perdita is that, and what views do you refer to? Not the Perdita that was intended to be deserted as an infant on the coast of Bohemia (whatever that is), but who lived happily ever after? Just what is it that is lost? I struggle to follow you sometimes.
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Some plants are highly sensitive to daylength. Onions for example. I sow them in February, which is still deep winter over here. They germinate in the house, but as soon as they are up, they go in the greenhouse all day for the light. They care not about the temperature, but being exposed to quickly increasing daylength, they know it is time to get on with it, and they grow on well. Deprive them just a little of light and they will not grow. Similarly, by mid-summer, the plants have reached full size, and the constant daylength is their signal for the bulbs to swell. It never fails, and by the third week in July, the stems toppple over, and that's it for the year.
Spinach is another example. I sow it late August. The plants develop gently until around now, then become dormant. They are very hardy and survive 10 degrees of frost easily. By February they begin to wake up again, and start to grow at a steady rate, making fine new succulent leaves. Harvest a whole year's supply in April or early May. I leave about 8 plants to make seed, and by July, they are waist-high with stems as thick as my wrist. I find it impossible to sow spinach in spring because the plants think they are behind schedule, and they quite literally reach for the sky and go to seed.
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You are what you eat. The way it is cooked is another matter, but I refuse to eat anything out of a microwave. We cook the old-fashioned way, and very importantly, all our potates and vegetables are steamed, not boiled. Immersion in water or enclosure in a microwave oven is the sure route to ruining good vegetables.
I did hear of a cook who died some years ago. He was employed in a small restaurant, and he gradually became very ill. Before long he died, and the post-mortem found that the man's hands and forearms were partly cooked. Investigations revealed that the microwave oven he used was faulty, and didn't always shut down when the door was opened.
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A slow progress into a cold and snowy winter..
According to the Danes, ECMWF are predicting that the mean temperature in Denmark for December to February inclusive will be 1.3 degrees above the seasonal norm at 1.8 degrees C. That will be no less than 3 degrees above the mean these last two winters, which were harsh.
http://www.dmi.dk/dmi/saesonprognose_udsigt_til_vintervejr
At the bottom of the article, the forecaster actually says seasonal forecasts have lost much credibility in recent times, but the good news is that seeing how almost everyone uses the same data from Reading, then the profession is wrong en masse. Do you mind if I forward to him your post here for his consideration?
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Hmm........what a difference 600 miles of latitude make. Here in southern Scandinavia we had just about the driest April on record, then about the equal wettest summer on record, and now what is beginning to look like the driest autumn on record. It hasn't really rained on this island since early October. My water-hole for the birds has dried out, and I had to fill it from the tap!Last spring and the end of October up to date this year appears to have born this out in southern France - the last 3 weeks appear to have been somewhat wetter than normal - the effect of a high over central Europe tends to encourage those nasty little lows into the Med.
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They definitely look like one of the Allium family.
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Well my garlic, sown around 1st October, popped up about 21st October. That's quite normal. Harvest next July.
The spinach and spring cabbage are just drowsing off as they are supposed to.
Lilac buds are perfectly normal in the autumn.
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[quote name=Gray-Wolf' timestamp='1320955949' post='2157748'
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i assume you mean the jetstream. we have had a large HP over NE Europe - it has been the reason we have not had a repeat of last year and are unlikely to in the near future
I keep records of twice daily observations here on this island. November 2010 started very differently to November 2011. Last year around this time there were depressions coming from the North Atlantic, stalling close west of Britain, while more than one depression formed in the Mediterranean Sea moving up through Poland to the Baltic Sea, stalling there, resulting in a blast of polar air over Denmark. This year there is also a Mediterranean depression early in November, but we have a very extensive and persistent high stuck over the Gulf of Finland region, and it is going nowhere. There is an inversion, so everything is just grey, and temperatures here are very constant right now, day and night 8 to 10 degrees ........the temperature of the Baltic Sea. Long may it last! I can put up with grey skies right until March as long as we don't get all that awful snow and frozen sea. Ugh!
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A book review....
That is alarming.
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Lol.
That's not relying on the science, that's a blog.
And neither has it owt to do with Nelson in my view.
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This also has the effect that over many years the actual parts of the sky we can see in our latitudes vary as well - imagine that in 13000 years' time it wouldn't be possible to see Orion from most parts of Europe,even though it is currently visible from all inhabited parts of the planet.
I could follow you on everything else but this.
If we could no longer see Orion from Europe, it would basically mean that Orion had become circumpolar in the Antarctic. I'll ignore gravity and the fact that Earth is not a true sphere, but assuming Earth revolves on its present axis in 24 hours as now, in order to point at Orion, Earth's axis would have to alter direction relative to the visible universe by anything up to 75 degrees. In consequence, days as we know them would only occur in our latitude when the sun's declination was between something like 35 South and 55 North, otherwise we would experience periods of perpetual day and perpetual night. Earth's climate would be very different to the one we know.
Of course, this assumes that Earth remains in its current path around the sun, relative to the visible universe.
Did I miss something?
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Seems the Berkeley study which was supposed to end the doubts and speculation about temperature trends has sparked its' own little debate:
That reads like a very dubious way of proceeding, and damages the reputation of science yet further.
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Winter has a grip on Greenland.
http://www.dmi.dk/dm...eb_om_groenland
While Europe may expect no serious cold weather in the near future, winter is established in Greenland and large parts of Canada – and this tendency looks likely to continue.
“In our latitudes, large scale air movements are such that when warmth moves north in one place, somewhere else cold moves south. It is as though there passes a wave, with heat on its crest and cold in the troughâ€, explains meteorologist Jesper Eriksen.
“Such waves normally travel from west to east, and Denmark experiences periods of both mild and cold weather. Occasionally though, warm and cold air masses become so extensive that the waves are brought to a standstill. That is the case right now."
"The current weather situation is likely to continue for at least the next ten days", says the meteorologist. "These particular circumstances bring mild, grey weather to Denmark, while Greenlanders can expect normal seasonal temperatures, or perhaps slightly colder than normal."
In Greenland right now – where perpetual night has not yet begun – the weather is characteristically sunshine with isolated snow showers. Eastern parts will however experience periods of heavy snow, and particularly near Illoqqortoormiut there will be times with strong winds from the north and northeast. This is down to depressions passing along the boundary between the warm and cold air masses taking a north-northeasterly track along Greenland’s east coats in the coming days.
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hi
I hope the attached pdf will help understand a little more about cold fronts such as the one we are posting about today.
That suggests to me John that writing a weather forcast from a surface pressure chart is in fact rather like playing the piano being guided by a sheet of music.
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What an interesting fruit never heard of them before, apparently they have to be bletted (half rotten) before they're edible - according to BBC.
Theres a recipe on there for a Walnut Bakewell tart with roasted medlars.
also, http://www.rhs.org.u...es/Medlar-jelly for roasted meat.
Also, what do they taste like?
Again, CJJ Berry, First Steps in Winemaking, page 195. Your good health Sir.
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Apparently there is a problem using atomic clocks to tell the time here on Earth. While the atomic clocks run very steady, it seems Earth's motion is more erratic than previously thought.
http://www.bbc.co.uk/news/science-environment-15546124
My question is not about the atomic clocks really, but what is causing Earth's motion to change? If Newton's 1st Law is to be believed, then there must be forces affecting us that we knew nothing of when in 1972 the present time system was introduced.
It occurred to me there might be a periodic alteration in the motion, but then, that wouldn't be erratic would it. Any ideas anyone?
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Sadly not kidding I just shook my head in disbelief at such nonsense.
Anyway I think we should just abandon the idea of moving clocks backwards and forwards and just leave them at summertime.
I agree, leave them where they are.
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Indeed, your right. At least they were from the DMI anywho.
Enjoy the banter
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Something to keep in mind or mark on the calendar, around 12 March when Venus will be much higher and more prominent, it will be close to Jupiter to form a bright double-planet spectacle in the evening skies. I don't have precise timing available and took this from a rather low-resolution orbital diagram, so within 2-3 days of that date ... we can get more specific timing closer to the event although the two planets should make an interesting spectacle for several days. The crescent new moon would also be part of the scene around the end of February and again the end of March, but not precisely with the close conjunction (moon will be full then).
That will be good to see, although not a patch on the show a few years back, when was it now, 2005? In the evening to the west we could see Venus, Mars, Jupiter and Saturn all very close in a line. It really was a marvellous sight.
New Research
in Climate Change
Posted
The Derbyshire affair was very difficult to properly investigate, though I thought the explanation of 9 ventilator closures being missing a most misleading circumstance to focus upon, and highly improbable. Whatever, the certifying bodies found it proper to increase certain aspects of foreship structural strength in vessels of that kind.
As I recall it however, the families of the lost seamen became incensed when it was discovered that other vessels of the same kind from the same builder had structural defects just forward of the engine room. These were not design defects, but due to shoddy workmanship. In particular it was said that girders under the weather deck had been cut too short to make a sound joint, and that spacing pads had been inserted to allow welding without an excessive gap. It was claimed this mistake had been repeated on other vessels. Something tells me cracks had appeared due to hull shear forces, and that several vessels were sent for repair. This was most unfortunate for not only the builder (who no longer exists), but also the Classification Society whose task it was to verify the vessel was built as designed using good shipbuilding practices.