Forgot your password?
typodupeerror

Comment: Re:Boom. (Score 1) 325

by IvyKing (#30545810) Attached to: "Home Batteries" Power Houses For a Week
Good question.

The main reason why a week's energy storage would be needed is if a large fraction of the electric energy production came from wind turbines (this could be either an isolated electric grid or a customer contracted with a wind energy company). It isn't unusual for calm periods to last several days and unfortunately for those relying on electric heat, those calm periods can be the coldest days of the year.

Speaking of wind - it would make a lot of sense to have batteries that would handle one to four hours of household use, provided that the batteries could take numerous charge/discharge cycles and had a reasonable cycle efficiency. Wind generation can have large variations in output over short time periods, which stresses the grid as most generation does not like rapid variations in demand (exception being hydro). A smart grid plus household batteries would allow the load to track variations in generation as opposed to generation tracking variations in load.

Comment: What about total installation cost? (Score 3, Insightful) 199

by IvyKing (#28597365) Attached to: Nanopillar Solar May Cost 10x Less Than Silicon
The cost of solars cell is low enough that infrastruture costs are a significant portion of the total installed cost. The quoted efficiency, 6%, implies that these cells would take up more area than silicon cells, and structiral support costs are proporional to area (I did see the text about possible doubling of efficiency). Another disadvantage to low efficiency cells is increased thermal loading.

Comment: Re:Why not.... (Score 1) 162

by IvyKing (#28162217) Attached to: Time Warner ToS Changes Could Mean Tiered Pricing, Throttling

Actually, the government has already made mandates about railroad pricing schemes.

I was going to make that point as well, and will add a bit to it. In the US, there are substantial advantages to be a common carrier as opposed to an industrial railroad, number being that a lot of state and local laws are pre-empted for the common carriers. In addition, eminent domain is a lot easier to secure for a comon carrier than an industrial RR.

Comment: Re:My theory why: multiprocessors (Score 1) 280

by IvyKing (#27876531) Attached to: Oracle Won't Abandon SPARC, Says Ellison

In addition to that, at 3.2GHz, light in a vacuum can only travel about 9.36 centimeters per cycle. Given a dialetric constant for the Si02 used in chip manufacturing of 3.9, you can calculate the velocity of propagation of the electromagnetic waves through the Silicon as about 50.6% of C. Therefore, at 3.2 GHz, the electromagnetic waves inside the chip can only propagate about 4.7 centimeters per cycle. You also can lose a bit depending on the switching speed of the transistors, but they actually become faster the smaller they are, so the real limiter is the propagation speed.

It's actually worse than that. The 50% velocity factor you mentioned applies only if the series impedance is dominated by inductance. At the scale of the interconnects on current micro's, the series impedance is dominated by resistance and the propagation time goes up with the square of the distance (i.e. a diffusion problem). Designers will put inverters on long interconnects just to speed things up.

Comment: Patents on FAT 8.3 filenames?????? (Score 1) 273

by IvyKing (#27398161) Attached to: TomTom Settles With Microsoft

The MS patents are specifically on the long file name stuff, apparently only on writing, and any patents on the original 8.3 format will have expired by now.

Since the 8.3 filename dates back to DEC's RSX-11, which was copied by CP/M, which was then copied by QDOS/86-DOS on FAT-12, it's not bloody likely that MS would have a patent on that. The idea of using FAT for QDOS/86-DOS was borrowed from MS's Disk BASIC, but I don't recall Gates or Allen patenting the FAT concept. If you're wondering what the heck is QDOS/86-DOS, it was bought by MS in 1981 and renamed MS-DOS.

Comment: Re:Tomato (Score 2, Informative) 272

by IvyKing (#27307693) Attached to: Botnet Worm Targets DSL Modems and Routers

Note that with a strong root password and usage of a non-standard port will help keep the bots away. Even better if you disable password authentication for SSH and use a key instead.

Even better yet would be setting up a user acount with a non-common name and su'ing or sudo'ing to do the administrative stuff. As an example, both OpenBSD and Solaris default to blocking root access by ssh. Another nifty ssh trick is to set it up sshd to drop most connection attempts after two attempts in a minute.

Comment: Re:Gah - energy was mentioned so the nukes come ou (Score 1) 227

by IvyKing (#27202407) Attached to: How the Economy Is Changing Clean Energy

You didn't notice above

Pebble bed is an exception

As a matter of fact I did notice that statement and I think it is absolutely wrong. A pebble bed reactor would be even easier to use for making weapons Plutonium than a light water reactor - you can pull pebbles out of the reactor without having to shut it down, whereas refueling in an LWR is done only once every 12 to 18 months. Probably the only reactor design that would be less useful for generating weapons grade Plutonium is the Integral Fast Reactor.

FWIW, the pebble bed reactor is based in part on the High Temperature Gas cooled Reactor (HTGR), sharing the helium coolant and graphite encapsulated fuel.

The Russians paticularly had a lot to say about the problems in their plants and used Westinghouse as a swear word to describe US plants with problems.

Considering the relative safety record of US naval and power reactors versus Soviet naval and power reactors, I wouldn't put much faith in what the Russians think of the Westinghouse designs (which are the basis for the majority of world's nuclear generation capacity). The US nuclear generation is now runnng at ~90% capacity factor, which speaks well for the future of the light water reactors.

Comment: Re:Gah - energy was mentioned so the nukes come ou (Score 1) 227

by IvyKing (#27197065) Attached to: How the Economy Is Changing Clean Energy
FWIW, I do have a degree in Nuclear Engineering and I know what I'm talking about with what's in the spent fuel from light water reactors. The proliferation potential from the pebble bed reactors isn't that much different from an LWR.

What is closer to dual use is the CANDU reactor, using natural uranium and a relatively low burnup (much lower 240Pu concentration). It also has provisions for on-line refueling, so it would be possible to have low burnup fuel elements to further reduce 240Pu concentration. The CANDU reactor cannot be licensed in the US due to it having a positive moderator temperature coefficient of reactivity. BTW, if you do not know the signifigance of 240Pu, you have no business making comments about "dual use".

Weekends were made for programming. - Karl Lehenbauer

Working...