Unthreaded
Alex Cull - Aug 30, 2016 at 10:49 PM
Many thanks, magic man!
Green Sand
Why do good weather forecasts go bad? Thu 8th 13:00 – 14:00
@Swansea , British Festival of Science
Meteorologist David Schultz reveals the scientific basis for why weather forecasts are possible, how modern weather prediction occurs by computer, and why forecasts sometimes fail. He will also describe a web-based tool that anyone can use to create their own weather forecasts.-Thu 5pm there's a lecture on lightning strikes against planes.
Other eco-propaganda lectures : Antarctic Ice Collapse (Fri ), 2 other Ice collapse lectures, New Space Solar, Solar Building Revolution, chemistry in UN Sustainable Development, Anthropocene Era :Mark Williams
stewgreen
@GC
CO2 extinguishers: I've used one too. Very fast & effective. I guess the CO2 is aided by the coldness of the decompressed gas and dry-ice chunks. One I used was a large one with a rubber hose and large plastic diffuser with a handle on it.
Knowing the smaller ones, I would probably had made the same painful mistake as you.
Fire Extinguishers and EU - I believe their insistence that they are all red is stupid. Much faster and easier (and no need to be able to read) to choose Red, White, Blue, Black or banned Green as required.
Pcar
@tomo
Hmm, similar time frame.
Would that have been outside the commonwealth pool?
First time I'd seen a GRP corpse. I had to ask a mechanic friend why the skeleton and glassfibre was all there was left.
Pcar
@AK, Aug 30, 2016 at 9:54 PM
Pcar. Lightning strikes per square kilometre may be low, but thunderstorms are not. We have experienced three in the past month.
Correct. Your point is?
Metal sticky-up things on higher ground will build up electrical charges and thus initiate upward strikes or preferentially attract downward strikes. Thus average lightning strikes per unit area may not be a suitable metric.
As already mentioned, a blade is the highest point, not the blunt nacelle. However, as it rotates any charge built up is dissipated.
Pcar
@ stewgreen (and everyone) there's now a transcript of this morning's radio interview with Peter Wadhams, and I've posted it over on CliScep:
Alex Cull
9:02 PM Pcar
I too saw the remains of a Reliant (Delboy) van at a set of lights in the 1980s - there was a clear air above it up to about 100ft - then a pillar of smoke (still summer's day). It must have gone off like a firework! - a skeleton and a pile of charred fibre.....
tomo
@It doesn't add up, Aug 30, 2016 at 4:18 PM
Pcar:
Cetane is only relevant to diesel engines. Technically it is measured in a laboratory diesel engine, although there are shortcut methods that are usually used (distillation and density measurements combined in a formula to produce "cetane index") that are simpler to measure and correlate well with engine performance.Cetane appears nowhere in the a href="http://www.petrostar.com/assets/downloads/Jet_A.pdf">specification for jet fuel.
Thanks for info.
My experience is IC engines, thus obvious BBC was confusing octane with cetane. Assumed jet kerosene was similar to diesel in specs as USA military vehicles like Abraham MBT can use either.
Does jet kerosene need to have lubrication properties for the injector pump(s)?
Pcar
Pcar. Lightning strikes per square kilometre may be low, but thunderstorms are not. We have experienced three in the past month. Metal sticky-up things on higher ground will build up electrical charges and thus initiate upward strikes or preferentially attract downward strikes. Thus average lightning strikes per unit area may not be a suitable metric.
ACK
Pcar:
There is a viscosity specification for jet fuel which is indeed related to fuel injectors among other things, but it is rarely a binding constraint (which are usually the safety elements of freeze point, associated with average molecular weight, PNA composition - and flash point).
Wide cut fuels are used by the military to offer them supply flexibility. That's why a tank can run on almost anything you can pour into it - you never know what you may or may not have access to in a war setting. It involves such exotica as variable compression ratio engines to cope with the different fuels. There are also special requirements - such as JP 5, which has a high flash point for added safety in aircraft carrier operations, and Jet B which has a very low freeze point and a large element of naphtha blended in for use in extreme arctic conditions - but that comes with a big flash point risk. Even more specialised is RP-1 rocket fuel, which is mainly composed of a very narrow range of molecular weights around C12 hydrocarbons, with polycyclic isomers being preferred. This requires considerable extra refining.