* Posts by Chemist

2004 posts • joined 24 Mar 2010

Lies, damn pies and obesity statistics: We're NOT a nation of fatties

Chemist
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Re: Obesety

"If people ate more fat, and less (read no) wheat they will lose fat, as their bodies will process fat more efficiently. It becomes great fuel instead of a spare tyre."

Fat is a great fuel, that's why we store it - for the bad times. It's a great fuel IF you actually use the calories it contains. I can't imaging what you think happens to this "more efficiently" processed fat IF you don't actually use the calories it contains - do you think that this "efficient processing" makes it disappear into thin air ? Or do you really believe the bacteria in your gut can metabolise excess fat in the diet without consequence. At the very least you'll get VERY hot. Food is measured in calories for a very good reason. 100g of fat is 800,000 calories or 3MJ. If that's metabolised, by you or bacteria, unless you lose a lot of it as high energy waste (like methane) the metabolism will result in a good proportion of 3MJ appearing as heat. If a large proportion IS converted to methane that's in the order of ~~50L (which is flatulence with a vengeance)

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Chemist
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Re: Hunter gatherer much

"Hunter gatherer much "

Summarizing what I've researched about this aspect of diet/behaviour :

Humans still have the basic physiology of hunter-gatherers from 10000+ years ago. It's estimated ( from the nearest we have to hunter gatherers today) that they expended ~~1400 cals average in physical activity every day as well as having a relatively low-calorie diet especially low in simple sugars.

Our metabolism, although wonderfully adaptable, still probably reflects this.

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Chemist
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Re: Don't forget...

Not to mention the parts of the country fed by direct rainwater supplies. Also many of the contaminants people worry about (e.g. growth hormone) don't get absorbed orally.

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Toyota to launch hydrogen (ie, NATURAL GAS) powered fuel cell hybrid

Chemist
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"So this just becomes the means for us to get those chemicals already being used."

I think there are more than enough already. This usage would massively increase the output. As already mentioned using sodium chloride solution as the electrolyte in electrolysis is terrible way of producing hydrogen. There are far more efficient electrolysis methods that don't produce any nasty by-products. For example using sulphuric acid - the acid isn't consumed in the process and is left in the cell with just more water being added as hydrogen and oxygen are produced

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Chemist
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"I would think if you built the electrolysis plants near the output of various sewage treatment plants (NYC, etc) that discharge back into the ocean, you could readily be bringing that water's salinity,"

Except ( and forgetting the previously mentioned severe environmental effects ) you'd merely be putting back the sodium & chlorine that you took out in the first place !

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Chemist
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Re: re:Electrolysis of brine produces as much chlorine as hydrogen

Potentially hypochlorite can be decomposed to NaCl and oxygen but the overall problem is the proportion of the energy budget being used to produce a high energy unwanted material.

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Chemist
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Re: re:Electrolysis of brine produces as much chlorine as hydrogen

"Ultimately you get HCl and O2,"

You don't . Potentially if you allow the chlorine to react with the sodium hydroxide you get a mix of NaCl and NaOCl. NaOCl is hypochlorite bleach and environmentally very damaging

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Chemist
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Re: re:Electrolysis of brine produces as much chlorine as hydrogen

"So if you try to electrolyse sea water this just happens, you can't prevent it as a by-product?"

There's some work on-going into selective electrodes but usually what happens with electrolysis is that at low current density selectivity might be achieved (depending on the characteristics of the competing ions) but at the sorts of current density required for production the selectivity is lost again.

In cases where fresh water supply isn't a problem then that is likely to be a preferred option. Even then I suspect that fairly pure water will be needed. I haven't worked it out but the energy cost of distilling water to purity it is much lower than the energy cost of electrolysis which (at 100% efficiency !!) is ~280kJ/mole - so 280kJ for 2 grams of hydrogen. With the real efficiency factored in the energy costs are ~~20 MJ/m3 of hydrogen gas + water costs + compression costs.

Usually in electrolysis of brine to manufacture chlorine they use pretty pure solutions which are much more concentrated than sea-water. The membranes used to separate the anode/cathode compartments are very expensive and prone to blockage/poisoning as are some electrode materials.

A possible non-electrolysis route is thermal decomposition of steam at high temperatures in the presence of a material that will capture the oxygen. The capture material must itself be capable being regenerated in a separate step. This is still at very early stages AFAIK

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Chemist
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Re: re:Electrolysis of brine produces as much chlorine as hydrogen

Why bother with seawater anyway - pure water + several other electrolytes just gives hydrogen and oxygen directly

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Chemist
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Re: re:Electrolysis of brine produces as much chlorine as hydrogen

Oh no, I'm afraid not. The electrolysis reaction is :

2NaCl +2H2O -> H2 + Cl2 + 2NaOH.

So to get 1 mole of hydrogen you also get 1 mole of chlorine - it doesn't matter what the concentration is. The volume of hydrogen produced is exactly the same as chlorine.

You can't just dissolve the chlorine back - it's a nasty, nasty reactive & toxic gas - it's not the same as chloride ion.

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Chemist
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"As for releasing nasty gasses you could just dissolve them straight back in, without noticeably affecting the concentrations."

No, sorry. Electrolysis of brine produces as much chlorine as hydrogen (~35 times as much by weight of course)- it's the basis of chlorine, sodium hydroxide ( and hence hypochlorite bleach) production. Generating significant amounts more of hydrogen from brine would overwhelm the environment with chlorine and probably sodium hydroxide.

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Chemist
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Re: Dreaming @Tom 7

""Hydrogen conversion (electricity->hydrogen->electricity) was over 85% efficient in the early 90's - so better than nuclear at 40%.""

Absolute garbage- and I've got some electrochemistry patents to my name. Even electricity> hydrogen is ~~60% efficiency.

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Chemist
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"It deals with rising sea levels too. What's not to like?"

I assume that's a joke

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Slapnav: Looking for KINKY dark matter? Switch on the GPS!

Chemist
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Re: That's a pretty video, but it's utter b*****ks

"Having started wrong it rapidly turns mystical and turns from "simplification based on erroneous data" to outright stupidity."

The (tedious) video also seems to be devoid of any significant connection to the rather interesting topic of topological defects in spacetime and their potential to be spotted by effects on time as measured by GPS synchronization.

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CERN's 2014 Xmas gift from the Large Hadron Collider: Two new baryons

Chemist
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"It's the beauty quark that gives the baryons their mass"

AFAIK the 'mass' is mostly in the gluons binding energy in any case

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LIFE, JIM? Comet probot lander found 'ORGANICS' on far-off iceball

Chemist
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Re: Because then we're probably not alone

"I find the idea of very BASIC organic compounds......."

Very basic organic compounds are found all over the place, simple organics form readily from CO, CO2, H2, H2O + energy. There's really no need to have them arrive by comet/meteorite.

(Remember the 'organic' bit doesn't mean LIFE or formed by living organisms - it is just is an (historical) name for carbon/hydrogen based chemistry.)

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Chemist
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Re: Because then we're probably not alone

"If life spreads around the universe it only has to happen once in the lifetime of the universe."

Basically bollocks - maybe true but so, so unlikely - it's a big,hard, difficult universe out there.

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Chemist
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Re: Because then we're probably not alone

"t only has to happen once in the lifetime of the universe."

It's a huge, huge distance to anywhere. Doesn't make it impossible. But at the mo' it's just organic compounds, not DNA, RNA whoa. Wait for the data.

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Chemist
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"Panspermia has some influential supporters, including Prof Stephen Hawking. Researchers have claimed to have found examples of extraterrestrial bacteria inside meteorites,"

Oh, good grief, It may have started somewhere else but so what, you can't keep passing the parcel forever. It had to start somewhere, at some time, why not here ?

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Has your STARFISH been DRIBBLING awful SLIME? Scientists now know WHY

Chemist
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Re: "A method implies an actor"

""sweating is a method used by the body to regulate temperature""

"sweating is a mechanism used by the body to regulate temperature"

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Firefox decade: Microsoft's IE humbled by a dogged upstart. Native next?

Chemist
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"What I believe I've determined is that FF leaks when you open/close tab"

Interesting Vic as I tend to have a lot of tabs permanently open and run for weeks between restarts of OS or FF. Obviously I do open and close some tabs all the time. I've never had any great concerns about memory leaks with FF, although I have had with some programs.

FF is currently using ~50MB less than when I last posted

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Chemist
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"Thus the commentards have spoken."

You are quite wrong (as usual) my anonymous 'friend'. But reading comments here and on other occasions, something is wrong somewhere. Some people have problems with memory leaks or crashes, others don't. Is there a common thread ?.

I use the same version of FF on 1GB, 2GB, & 8GB memory machines ranging from a single core atom & celeron 32 bit to the 64bit machines dual-core AMD & intel upto latest 4 core i7 and have a very similar experience on all (although naturally some are LOT faster than others) . Few crashes and memory usage around 600MB with ~10 tabs open, no obvious leaks. That experience (since ~2006) is limited to just Linux. It would be interesting to see if there is any correlation with OS or maybe it's some hardware thing.

BTW we all know 1080p in 1 bit of RAM is silly.

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Chemist
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"So you repeated browser crashes (once a day for FF is not uncommon) probably go unnoticed."

Would you like an upvote out of pity ?

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Chemist
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"Well if you are running Linux, you are used to patching and compiling your own kernels, as well as spending hours on a command line fixing dodgy software."

BTW I know, anyone who has read reviews on Linux distros (here and elsewhere) knows and I suspect YOU know that you don't need to compile a kernel (or use the command-line to install Linux)

And as for your comment about spending hours fixing dodgy software - beneath contempt !

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Chemist
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Re: Forgetting something Mr Chemist?

"What would one use to download Konqueror or an ftp client or even wget?"

They all come with my preferred OS.

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Chemist
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Re: Ten years and still waiting...

" Ten years and still waiting...

...for a Firefox version that won't crucify a PC with more than a few tabs open."

You should use Linux !

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Chemist
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Re: Forgetting something Mr Chemist?

You haven't got an ftp client ?!!!

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Chemist
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Re: Firefox is the most stable on Android

"Never buying their under-supported crap again."

Not bothering with troll- you are just a (AC) liar

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Chemist
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"Well if you are running Linux, you are used to patching and compiling your own kernels, as well as spending hours on a command line fixing dodgy software.So you repeated browser crashes (once a day for FF is not uncommon) probably go unnoticed."

a) not compiled anything for years !

b) Use the command line a lot - just not needed

c) You are a trol*

c) You are illiterate! (BTW)

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Chemist
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"Constant crashes on Android here as well. Just like on the PC, FF on Android is not fit for purpose."

Oh, an AC with a 'valid' opinion. What possible reason could you have for being that ?. No, thought not

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Chemist
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" without IE, what would you use to download your browser with?"

Konqueror or wget or ftp or ........

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Chemist
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"native beats Firefox because ff crashes constantly"

Well me and mine use FF ALL the time day in/day out and if it crashes it's noteworthy - maybe 2-3 times a year.

Mind that's running all machines (6) under Linux

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BBC clamps down on ILLICIT iPlayer watchers

Chemist
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Re: Get_iplayer still working here

Radio downloads working OK now

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Virgin 'spaceship' pilot 'UNLOCKED tailbooms' going through SOUND BARRIER

Chemist
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Re: "Wealthy customers have signed up in large numbers to see a black sky "

"You seem to have forgotten the recent deaths in the Himalayas ......"

What's that got to do with it. He didn't say climb a dangerous mountain and for that matter the stars against a black sky were magnificent only a mile from Salcombe with our boat tied to its pontoon.

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Snapper's decisions: Whatever happened to REAL photography?

Chemist
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Re: Total light?

@ Steven Jones

I certainly can confirm that my 550D ( love it as I do) isn't a match for my full-frame 6D esp. in noise performance even though the pixel count is ~ the same. Shooting a starry sky, for example, I was seeing far, far more stars without any noise artifacts.

(BTW though some of the finest slides I've ever seen where 21/4 inch Hasselblad photos)

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FATTIES: Boffins say their miracle sunshine skin cream 'prevents obesity'

Chemist
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Re: Bioavailability

" Bioavailability

What you swallow is not what you absorb. Quite a few of the unhealthy foods have high bioavaliability while the healthy ones have lower bioavailability."

I suspect you don't know what bioavailability means. Hint: it's not just the proportion of material absorbed.

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Chemist
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"nitric oxide last week - it helps open blood vessels to prevent high blood pressure"

It's used for a number of control mechanisms in the body. AFAIK (it's mostly not my fields of expertise), there are 3 main mechanisms. One form of the enzyme eNOS (Nitric oxide synthetase ) is activated in blood vessels, I assume under some control, and converts the amino-acid arginine into nitric oxide (+citrulline) . This relaxes the blood vessels. Another NOS, iNOS generates NO by the same mechanism to generate an inflammatory reaction as part of the response to infection etc.

I think, also, that nitrates/nitrites in the diet can generate a background level of NO which may help blood vessel control.

Synthetic nitrites are used to produce a rapid rise in NO levels to alleviate angina symptoms.

But its nature - it modifies the activity of lots of proteins and has a number of recorded effects ( on insulin & airways for example) may mean there are plenty of unknown functions (good & bad)

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Chemist
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Re: Miracle!

"During the first 10 minutes or so of exercise the body burns carbs as fuel, from 10-60 minutes the body turns to burning fat. Normally from 60 minutes + the body will switch to burning muscle as fuel since proteins burn slower and it's slow energy you need."

I think you'll find that this is not correct.

A fit, well-fed individual will have ~~1300 cals of stored carbohydrate, mostly as glycogen, At the start of exercise this will be mobilized to the muscles. On it's own it will provide enough energy for ~~2hrs cycling, however fat mobilization/metabolism which is slower, starts to contribute from relatively early on and becomes significant well before carbohydrate is exhausted. As most people have plenty of fat (maybe 160000 cals) provided the exercise is of a lower order than 'flat-out' fat can provide energy for a long time. Catabolism of protein is a response to starvation in the main, although anyone seriously trying to lose weight by just dieting (i.e.starvation) should try to maintain whole-body muscle fitness by exercise.

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MEN: For pity's sake SLEEP with LOTS of WOMEN - and avoid Prostate Cancer

Chemist
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Re: a study from Canadian health researchers

Re :a study from Canadian health researchers

AFAIK the correlation between frequency of ejaculation and prostate cancer is already well-known.

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Voyager 1 now EIGHTEEN LIGHT HOURS from home

Chemist
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Re: Time dilation

"A constant 1g acceleration would get you to near "

But to get that constant acceleration the energy requirement increase rapidly as ->c

e.g rel. kinetic energy for 1 tonne at 0.9c & 0.999c compared with 'convention' kinetic energy

0.9 ~2E20 J ~3.6E19 J

0.999 ~2E21 J ~4.5E19 J

So an order of mag. increase of total energy required to go 0.9c -> 0.999c

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Happy 2nd birthday, Windows 8 and Surface: Anatomy of a disaster

Chemist
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Re: Snatching defeat from the jaws of victory...

"Last time I tried Linux and attempted to install Firefox I first had to find an installer for the distribution I was using."

Strange that as I've installed OpenSUSE for years (and years) and Firefox was included as one of the default browsers - no need to specifically install at all - that's part of the ease of use of a full-featured distro. Even installing a program that isn't in the distro is often a 1-click job

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COMET 67P is basically TRAILING a HORRIFIC STENCH through space

Chemist
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Re: Hydrogen Sulphide doesn't stink

"Really pure Hydrogen Sulphide is almost as odour-free as hydrogen cyanide."

Do you have a ref. for that ? AFAIK pure hydrogen sulphide is detectable by its smell at ~ 1ppm but at higher concentrations the smell is less or indeed undetectable. I've personally experienced this as walking into a lab full of people I could smell hydrogen sulphide (initially) when the entire room full of staff told me they had smelt it 'a few minutes earlier' but it was 'OK' now. I got them all out into the corridor, tested the air ( with a draeger tube) and the concentration was ~100ppm. A leaking rubber tube was the the cause even though the kit was in a good fume-cupboard.

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It's even GRIMMER up North after MEGA SKY BROADBAND OUTAGE

Chemist
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Re: Well..

"Saas Fee. Dullest ski holiday i've ever been on. (FYI)"

Well I don't ski but I do walk/climb. If I did ski I could do it at the moment - many of the main ski teams are here including Japanese. The Swiss team has >18 minibuses.

I can't see the runs at the moment as there is some cloud ( it snowed last night down to ~3000m )

http://www.saas-fee.ch/en/aktuell/Webcam_Mittelallalin

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Chemist
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Well..

I live in the a very nice part of 'the north' surrounded by many of the areas you attempt to mention although I'm in Saas-Fee, Switzerland at the moment. Certainly my broadband connection is working at home as I've just looked at a directory on my server using fish://

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Microsoft, Docker bid to bring Linux-y containers to Windows: What YOU need to know

Chemist
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Re: It's sounding a bit vague

"Yes, I feel they're at the stage of: "Oh, I want one of those!""

or even " "Oh, I want you to think we've got one of those!""

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Scientists skeptical of Lockheed Martin's truck-sized FUSION reactor breakthrough boast

Chemist
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Re: Clean ?????

"You need a process that creates helium-6 for it to be clean,"

Would you care to elaborate on this ?

AFAIK He-6 has a 1/2 life of <1 sec and decays by both beta and alpha emission.

He-4 is stable and the extra neutron released to form it is the one required to make more Tritium

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Chemist
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Re: Patents

"Isn't half life affected by relativistic effects?"

Sorry, don't understand the context ?

Tritium has a half-life of ~12 years, it's often incorporated into drugs/ligands for studying biological mechanisms and these have a useful working life.

If you send it up to close to the speed of light it's 1/2 life will increase to multiples of 12 years depending on the velocity but I don't know what that's got to do with this topic.

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Kill off SSL 3.0 NOW: HTTPS savaged by vicious POODLE

Chemist
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Re: smug

"Poodletest doesn't get it right with Firefox - it is vulnerable."

It does now - it's been updated.

Also "So in short: Firefox is less likely to downgrade to SSLv3 if the server follows best practices on cipher selection, even if SSLv3 is still supported."

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Chemist
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From ISC

Their current page for this includes links to test sites

For clients it's https://www.poodletest.com/ (Javascript needs to be enabled)

FYI OpenSUSE 13.1 Firefox ESR not vulnerable, SeaMonkey (2.29) not vulnerable, Konqueror (4.10.1) vulnerable

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