Become a fan of Slashdot on Facebook

 



Forgot your password?
typodupeerror

Comment: An interesting question (Score 1) 309

by Andy Dodd (#49610803) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

Tesla's vehicles charge to only 80% capacity by default, because this GREATLY improves the number of charge/discharge cycles you can get from the battery. (Li-Ion/LiPo batteries get "stressed" out the most at full charge.) Tesla gives owners the option to charge that last 20% if they expect to need the range.

Are the 7/10 kWh ratings of these units the raw rating of the batteries in the pack, or have they already been derated to the 80% level?

If they've already been derated to the 80% level, that resolves some of the potential conflicts in terms of lifetime indicated in the article. (1000 cycle "rule of thumb" vs. Tesla's warranty.)

Comment: Re:danger vs taste (Score 1) 629

by Andy Dodd (#49570501) Attached to: Pepsi To Stop Using Aspartame

Which makes me wonder - is the real reason Pepsi is doing this neotame?

Neotame is, I believe, about as expensive per unit volume as aspartame to produce, BUT it requires far less volume as it's 7-10 THOUSAND times sweeter than sucrose instead of 200 times in the case of aspartame.

The patent for neotame expires on July 8 of this year - http://en.wikipedia.org/wiki/N...

So could this actually just be a cost-cutting measure that they're trying to market as "being good for you"?

Comment: Re:danger vs taste (Score 1) 629

by Andy Dodd (#49570399) Attached to: Pepsi To Stop Using Aspartame

One thing to keep in mind is:

Standalone products sold for use as a human-usable sweetener are going to be different than industrial uses.

The majority of artificial sweeteners happen to be significantly more potent by weight than normal sugar. As a result, nearly all of them are mixed with some sort of filler (usually dextrose in my experience) when sold as a "table sweetener". This is to allow the consumer to have any hope whatsoever of measuring them out in a consistent manner. Even with the fillers, they're significantly reduced in calories compared to sugar.

Splenda, Stevia, NutraSweet, they're all mixed with fillers when sold as a consumer-usable sweetener. These fillers aren't present in "industrially-produced" products that don't need the fillers, like soda off the shelf.

As another example - aspartame has as many calories per unit of weight as sucrose. However, it's 200 times sweeter than sucrose, so the amount used is so little that the caloric content of a product with the same sweetness is negligible. Think of a 12 ounce can of Coke - normally 33g of sugar, but only requires 0.16 grams of aspartame. For Coke, this isn't a problem sine they mix hundreds if not thousands of liters at a time, so the amount of aspartame used is easier to measure out - but imagine trying to measure out 0.16 grams of aspartame as a user!

Comment: Re:danger vs taste (Score 2, Interesting) 629

by Andy Dodd (#49561533) Attached to: Pepsi To Stop Using Aspartame

Last I heard, the saccharin mess was a combination of two things:
1) They used insanely high doses for that study too, if you replaced the saccharin with sugar you would've killed the rats rather quickly.
2) The findings that DID occur were later proven to be specific to rat metabolism that did NOT apply to monkeys including the "human" subvariant.

Comment: Re:danger vs taste (Score 1) 629

by Andy Dodd (#49561497) Attached to: Pepsi To Stop Using Aspartame

"also triggers insulin production"

If you're a Type I diabetic like myself, this is not an issue.

Diet soda is a miracle for Type I diabetics.

I am disappointed at how Pepsi is giving in to the perception that aspartame is dangerous in any way. A good question is - sales of "Diet Pepsi" were falling - was this ALL variants of "Diet Pepsi" (such as Pepsi MAX and... I forget the other variant. Last I checked there were three variants of "Diet" Pepsi, there was "original diet", Max, and something else.) "Original diet" used aspartame exclusively, others used different sweeteners (Acesulfame K, Splenda). In many cases, those sweeteners were used simply because *they tasted better* and that's likely why sales were falling.

Comment: Re:With the best will in the world... (Score 1) 483

Well one of the biggest limitations for wind and solar is that they're unreliable in terms of availability. We don't have the storage technology available to achieve greater than around 20% grid penetration of wind/solar anywhere except for a small handful of places (namely Denmark, who is next to Norway, who have a HUGE hydro power reserve that they can throttle up/down in response to Denmark's supply/demand.)

If this new process can throttle efficiently depending on how much input power is available, it might be a solution to the storage problem.

Comment: Re:"although not with bug-free results" (Score 5, Informative) 160

by Andy Dodd (#49559695) Attached to: Google Officially Discontinues Nexus 7 Tablet

The article was pretty poor.

There were two Nexus 7 devices:
1) The 2012 Nexus 7 (often referred to by its internal codename, grouper), using an NVidia Tegra3 chipset. This did get Lollipop, although it was kind of "meh", mostly with performance issues, showing that the hardware was getting a little on the old side. Google may have been trying to make up for the Galaxy Nexus getting dropped prematurely due to TI by keeping a different Nexus device supported for as long as absolutely possible. This device was discontinued in Summer 2013 when its successor was announced.
2) The 2013 Nexus 7 (often referred to by its internal codename, flo), using a Qualcomm Snapdragon S4 Pro (APQ8064), pretty much the same as the Snapdragon 600 at a slightly lower clock speed. This runs Lollipop well due to newer hardware. This is the device that was just discontinued.

grouper was always a bit "meh" - I don't know if it was the fault of Asus or NVidia, but Tegra3 tablets from Asus were always notorious for poor storage performance. I think other Tegra3 tablets had similar issues, but honestly - Asus was the largest Tegra3 customer by far thanks to grouper and the Transformer series of tablets, so it's hard to tell who was at fault.

The fact that flo didn't have grouper's storage performance issues (same device manufacturer, different chip inside) indicates it was probably the Tegra3.

Comment: Re:Here's to hoping they don't find oil (Score 1) 152

by Andy Dodd (#49545047) Attached to: Yellowstone Supervolcano Even Bigger Than We Realized

Cooling the magma into stone could have long-term negative effects - a lot of this magma has quite a bit of dissolved gases.

The end result is that when it erupts, the gases come out of solution and frequently drive the eruption (think shaken-up soda bottle)

Cooling the magma will stop progression initially, but will cause the gases to accumulate - this could lead eventually to an even more catastrophic BOOM.

Comment: Re:Like 'sunset' (Score 1) 194

by Andy Dodd (#49536241) Attached to: Yahoo Called Its Layoffs a "Remix." Don't Do That.

No, "sunsetted" has been around for a long time. Although historically it's been used to describe systems that are old and obsolete and getting replaced with new ones.

You'll hear "sunsetted" frequently in the military to describe systems being retired, usually after decades of service because they're falling apart and their replacement has been in production for nearly a decade.

You can't have everything... where would you put it? -- Steven Wright

Working...