Berkeley CSUA MOTD:2006:March:11 Saturday <Friday, Sunday>
Berkeley CSUA MOTD
2006/3/11-13 [Science/GlobalWarming] UID:42189 Activity:moderate
3/11    GE may have figured out a cheaper way of making H2:
        \_ I'm amazed the manufacturing of the aparatus has that much
           effect on the cost to generate the hydrogen.
        \_ Umm.. how much energy does 1kg of H have vs 1 gal of gasoline?
           I would suspect the gasoline has much more.
           \_ Answered my own question, H has a LOT more, like 5x.
              \_ Weird, I googled for this and most of the info I got
                 suggested that 1kg H2 has about the same energy
                 content as gasoline:
                 1kg H2 energy content: 120-140kJ
                 1gallon gas energy content: 130kJ
                 1kg H2 energy content: 120-140MJ
                 1gallon gas energy content: 130MJ
                                                 \_ These should be MJ, not kJ.
                                                    (for both substances)
                                                    \_ Sorry, I ment to change
                                                       from k to M. Thanks for
                                                       catching this.
                 \_ guys, both links are very clear:  H2 has ~ 3x or higher
                    energy content vs. gasoline by weight, but in terms of
                    volume, it has issues
                 \_ this is why i don't believe in hydrogen economy.  We
                    needs just bite the bullet and save gas bits by bits.
                    \_ Yeah, see, there's thingy some people call 'technology'.
                       By applying this, this, 'technology', people are often
                       able to solve problems in surprising ways....
                       \_ there is a thing call knowledge, which separate
                          fantacy from reality.  If you want to get hydrogen
                          competitively TODAY, you can only obtain it from
                          natural gas, coal, or other form of fussel fuel.
                          Rest of these things are as interesting as human
                          cloning:  vast potential, but far far away down the
                    \_ great sustainable plan you got there.
                    \_ Funny, this is the reason H looks good to me.  If
                       they can really produce it for $3 a kilo, it will
                       eventually be cheaper than gas.  I'm curious about
                       the cost breakdown though.  What electricity cost
                       are they assuming, etc?
                       \_ If you assume the above numbers, corrected to MJ
                          instead of kJ, and convert to kWH, then divide into
                          three dollars, you get 8.3 cents per kWH.
               \_ Why would you compare energy/mass to energy/weight?  How is
                  that meaningful?
                  \_ The density of gas is ~ 0.73 g/ml, so gas has an energy
                     density of ~ 47 MJ/kg, which is about 3x smaller than H2.
        \_ You can pour 1kg of gasoline into a bucket, and use it.  You can't
           do that with a 1kg of Hydrogen, which is the whole issue with
2006/3/11-13 [Computer/HW/Drives] UID:42190 Activity:nil
3/11    Why does it seem like nobody manufactures slot loading CD/DVD drives
        anymore?  While I understand they might be more expensive to make,
        they are way more cool and I wouldn't mind paying a premium over the
        tray loading models.
        \_ I'm told that they have a higher failure rate.  there is also
           the problem of the mini-cd's getting stuck in them even with
           the proper adapter.  --Jon
        \_ Apple uses slot loading drives from various manufactures, so
           they are still made. They are not widely available to end-users.
           If you are really interested in a slot loading DVD drive Plextor
           makes one that is on sale:
           imo, the ~$50 premium isn't worth it.
           \_ That's the only one I could find, and when you consider the
              Plextor premium too, it's like 200% more expensive than a
              comparable drive from another manufacturer. -OP
              \_ If you are willing to hunt around Weird Stuff or Halted
                 you can probably find older Pioneer or Plextor slot loading
                 drives. [ I know you asked for new, but if you really want
                 slot loading... ]
        \_ Wow, that sucks; I bought a Pioneer DVD slot loader just a few years
           ago and I love it.  Trays suck!
        \_ if you *REALLY* want to know, i can harass my clients about it :p
2006/3/11-13 [Uncategorized] UID:42191 Activity:nil
3/10    My freezer has a very effective 'anti-frost' unit.  My problem is that
        I typically only need ice cubes maybe once every month or 2, and when
        I go to use them, I find they have half-sublimated away and I have
        a tray full of half-size ice cubes.  Short of disabling the anti-frost
        feature, is there anything I can do to stop ice cubes from shrinking?
        \_ You could cover the tray once it has frozen over.  Try seranwrap?
2006/3/11-13 [Science/Battery] UID:42192 Activity:nil
3/11    Should Ni-MH batteries be occasionally discharged completely and if
        so, how often? Someone told me every 10-15 uses. Then again it might
        bi for Ni-Cd batteries, I forgot. Any help on this subject would
        be greatly appreciated, thanks!
        \_ see FAQs
           \_ any Li-ion faqs?
              \_ gawd, STFW.
Berkeley CSUA MOTD:2006:March:11 Saturday <Friday, Sunday>