Posts by Chemist
1424 posts • joined Wednesday 24th March 2010 19:26 GMT
Re :
2-methyl-3-buten-2-ol is apparently a sedative but the dose required is supposedly 2-5 grams. I think the amount of beer required to get that amount of 2-methyl-3-buten-2-ol might contribute to DEATH let alone sedation
Oh, Yes
I can surely see why I'd want this as a user ! TFIC
Re :First successful mass market hybrid?
Seems to have one electric motor and therefore does have drive shafts. Certainly cut-away views look as though it does. According to The Telegraph :
"General Motors is working on the problem and this autumn plans to unveil a mechanical direct-drive from the engine to the front wheels through the existing twin-clutch planetary gearbox. This would reduce the energy losses of turning petrol power into electricity to drive the car at high speeds, and would also give the Ampera more spritely overtaking performance."
Re : replaceable battery packs
"any 10-20 minute stop for coffee or shopping would put another 40 miles in the tank"
So you're planning to recharge a 16kWh battery in 10-20 mins. ?
That'd be a 64kW connection then or 20+ electric kettles worth. That should be some cable ( or indeed street lamp )
Re : zombieism, a character of F. domesticus
I think the important question is whether your cat cares if you are alive or not !
Re : "The cat thinks, therefore it is."
or isn't
Re : LOL true dat
Agree entirely - NOTHING can break a one time pad !
Anyone downvoting AJS is ignorant
Re : A qubit is not a cat.
On the other hand Qubit sounds quite a good NAME for a cat !
Re : "a barrage was built across the Strait of Gibraltar "
You do realise that the straits are anything upto 900 metres deep at the narrows. That's a seriously grand civil engineering project ! Even with a longer barrage it's still ~300 metres
Re : Hydrogenation
Chemically it's certainly possible to generate a range of fuels from a carbon source + hydrogen. The efficiency is pretty poor and involves CO2 emissions. Hydrogen being used in fuel cells is a more efficient process AFAIK but would involve massive production of the cells.
Re : Some other solar chemical alternatives
I'm sorry you can't get methane + hydrogen from water + CO2
I think you'll find the Solchem project reaction (was supposed to be ) CH4(methane) + CO2 -> H2 + CO + H2O. I say supposed to be because the stoichiometry is wrong in the only published explanation I can find. I'd make it CO2 +CH4 -> 2CO + 2H2
I've just found a pdf sponsored by the US DoE that confirms CO2 +CH4 -> 2CO + 2H2
http://www.osti.gov/bridge/servlets/purl/10131314-JCwtG8/native/10131314.pdf
So basically it needs methane as a feedstock
Re : Why transport it as electricity?
Sounds great
However
Generating hydrogen as feedstock by high temp. electrolysis has an efficiency ~50%
Concentrating carbon dioxide from the atmosphere must be quite inefficient due to its low concentration. Of course if you have a good concentrated source that's go to be better.
Making hydrocarbons from carbon dioxide/ hydrogen is still under active research - final efficiency ??
Burning the hydrocarbons to generate electricity ~~35% efficiency.
So currently the overall energy efficiency ( <<17%) looks very poor which is presumably why nobody is rushing to use this to store renewables generated during off-peak times.
Re : What? →
" involves staring at a progress bar for a couple of hours"
Last clean install I did, including most of the applications, took 19 mins. admittedly from a DVD
That was with OpenSUSE 11.2 - updates took longer but that depends on broadband speed and how busy the servers are and in any case the system can be left to get on with it
Re : GPS
What sort of useless GPS is it that gives an error of 3km ?
Re : It's when I hear nonsense like this ...
Certainly when I had a Windows partition I used to back it up from a Linux partition
Re : Wow
"63% of retirees indicated that their monthly love-making attempt was accompanied by a somewhat off-putting creaking sound."
They should get a new bed or whatever !
Re : "I want to USE my computer"
Agree entirely - I've used Suse since ~5.0 I think
Almost everything here now is OpenSUSE 11.2 and it all just works !
Re : Why none of this matters
If you need to try a distribution on your hardware then the usual route is to try a LIveCD which will let you run all your hardware without installing to the HD . When you're happy that it looks OK then most will let you then install directly to the HD from within the LiveCD system.
In my experience OpenSUSE will install on most desktop systems.
It's also possible to use a bootable USB drive which can then be used as a portable Linux
Re : Why, oh fecking why, is a title required?
I agree that laptops are harder although I had no problems on a Lenovo or Asus 900, but installing on desktops is now generally straightforward. I've installed 4 desktops of various specs. & vintages with OpenSUSE 11.2 in the last few months and had NO issues.
Re : No problem
Correct - but why the joke icon ?
Re : RAM
Just to extend this. I'm currently running Firefox with 6 tabs open, Thunderbird and a system monitor on a 1GB laptop using openSUSE 11.2 32-bit and the total program memory usage is ~380MB including system, desktop and X - adds up to 135 processes having some memory usage.
FF has ~90 MB (which I find typical) + 24 MB shared
TB 28/20 MB
Re : text-interface obsessives
There may well be lots of people who want to interact by CLI with programs but the REAL advantage is being able to embed this type of control into scripts, cron jobs and programs.
Re : RAM
Multi-tasking doesn't do away with the need for sufficient memory. If you have several programs running then you need enough real memory for them unless you are prepared to wait for them to be swapped back.
What do you imagine multi-tasking does - magic ?
Re : Speed
Agree entirely.
Yesterday driving on fast A-road at the speed limit+ I had another car a few feet behind and so far out in the road that they were often over the white line. This went on for a few miles even though the opportunity to overtake was there.
Today on a WIDE road I was overtaking a parked car whilst still within the white line and a POLICE-CAR came round a bend ahead over the white line with a car's width of empty space next to the kerb.
Speeding might contribute to injury and to some extent the original accident but there are far more dangerous driving practices that cause accidents in the first place that cameras will never spot.
Re : WTH ? →
I'm rather interested in the amounts of RAM required for the different OSs.
Linux 64M (128M preferred)
Win 256M (512M preferred)
OSX 256M (512M preferred)
Thunderbird 3.0.4 is running on my 32-bit OpenSUSE laptop using 29M + 22M shared memory so I'd certainly want a good few multiples of that minimum as installed RAM. I'd be interested in what people are 'seeing' as real usage figures on other OSs
Balls!
"But I suppose now popstars do international relations, chemists now do physics on footballs they've never examined"
I think you'll find that most chemists know far more about physics than 99% of the population.
Re : "allergic to wifi", &c.
I suspect the risk of problems with cell phones and Wifi is very low.
However the heating risks may not be the only way E.M. radiation may interact with living systems. For example living cells maintain an apparently low voltage across their membranes of the order of hundreds of millivolts. But the membrane is very thin (~5nm) so the effective field strength is very high at many thousands of volts/cm, further membrane proteins are gated by this field with ion channels etc. opening or closing as the voltage changes. So it seems at least possible that cell membranes might be capable of being influenced by E.M fields without heating effects. In particular neurons, which are extremely extended make particular use of this cell membrane voltage and it's changes.
This is speculation - I've not had time to look at the literature for any investigations
Re : The maths
Whilst I don't think mobile phones pose a sig. risk the comparison with a hairdryer is a little dubious.
Hairdryers put some of the heat onto the skin - probably much less than half the machines output, but electromagnetic radiation penetrates the skin and *could* cause effects deeper in the tissue.
Re : Other Devices →
"users drive round with the antenna almost directly over their heads"
They'd be in a Faraday cage surely.
Mind, if it's California they might actually be driving around with an antenna directly on their heads
Re : yeah right
But the bacteria were there !
At what concentration and how viable is another matter
Re : Of course
Most modern desktops allow for root -type operations, like creating accounts, from a users desktop simply by asking for root password to authorize the operation. That's how software is installed, user accounts modified and system files altered in OpenSUSE for example.
If you need the command line then open a console on the user desktop and su to root
Re : How can it be both "uncommon" and ..
One possibility is that it isn't very infective to the general population although very dangerous when established or that the jets don't produce a very effective aerosol especially if it has to go through the ventilation system first.
Re : water and freezing →
In any case even 'normal temp.' people will suffer frostbite on exposed tissue often in a very short time.
Re : It's funny, people talk about
Ditto. I don't have any problems with excessive memory usage either.
Re : ...and here comes the crunch
EEEBuntu is fine
Re : Good discussion
Whilst I agree with you about the discussions there really aren't that many downvotes - there are always some idiots around
Re : Could be WINE based, not simply a remote desktop
It's not a universal solution though. Some Win programs work really well with WINE - I personally use Photoshop Impression, PTGUI - the panorama generator and also the PIC IDE from Microchip - just click on the icon and it just works.
But lots of programs don't.
Re : Bring your own OS
I normally use OpenSUSE on my other machines but EEEbuntu installed without any effort on my Asus 900. I only use it for traveling but it works really well for that. Decoding raw photos, web, e-mail and SSH.
I also favour the self-built kit - allmy desktops and servers are home-built. The last one I built, an Intel dual-core only cost ~£300 with a cheapo monitor
Re : Re: Article request
Lots on lots out there - depends on exactly what you want.
For example for ~$220
http://microcontrollershop.com/product_info.php?cPath=154_170_280&products_id=3588
or http://www.simtec.co.uk/products/EB2410ITX/
No experience of any of these I'm afraid
Re : VNC
I'm struggling with the novelty of this. Using vncviewer & tsclient from my various linux boxes to other machines on both the local and remote networks is an everyday thing. My wife runs remote sessions on her school's Windows system (far more reliably than from a Window's client by the way). Although these clients don't usually run in a browser they can ( certainly VNC ).
Have we missed something in this announcement ?
Re : Re: -1
"However, if the patent were to specify every detail, then someone else could simply scale the plans up slightly and circumvent the patent."
That is nonsense ! Simply scaling-up would be 'obvious' in the strict patent sense.
Patents describe inventions in sufficient detail that 'one skilled in the art' can understand/repeat the process/construction or whatever
Re : @Chemist →
Thanks Trevor - I agree entirely about a determined attack
Just to round this out - I also only have one user account authorized for SSH - this has a non-trivial username and a long complex password. I also immediately su to a working account after login.
( I know I could use other methods but I've written a custom passphrase > complex password generator that I use for other things anyway)
Re : Same old story
Certainly EEEBuntu installed on my Asus 900 without any probs. Wireless worked perfectly
Re : Apologies
I use a non-standard SSH port and although this could be seen as security by obscurity it is interesting to look at the router logs. When SSH is on a high, non-standard port I've never seen ANY attempts to login. On the standard port they run at ~10/day
Re : Linux viruses in the wild and RST.B →
Best of luck with the brute force ssh attempts !
Re : The problem is...
"GNU / Linux is just a bunch of components"
Which somehow provides excellent service on my 6 workstations/servers/laptops & netbook. Does everything I want so why should I give Apple or MS my money ? In any case the workstations often run (for days ) protein dynamics simulations that don't have a Windows version
(I assemble all my own desktops so no MS tax - the latest dual-core only cost £300 pounds )
Re : @Chemist
I take your point. Re-painting a plimsoll line is a serious breach of maritime law ( I think ) and must surely void any insurance.
