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Comment: Re:danger vs taste (Score 1) 478

by Rei (#49565631) Attached to: Pepsi To Stop Using Aspartame

Having a strict target is not impossible, and when the difference between consumption and expenditure is on the order of 500 calories, you have room for error on both ends - on your estimation of your consumption and on the estimation of your burn.

There was a rousing ITV, or BBC, I don't remember, documentary on a woman

Whoa - throw away all of the scientific data, there's an anecdote here involving an TV show about an uncontrolled experiment whose data we can't see and whose name you can't even remember!

The human body works on calories. The human digestive system does not throw away energy from digestible substances. It's energy in vs. energy out.

Comment: Re:With the best will in the world... (Score 1) 370

by Rei (#49564703) Attached to: Audi Creates "Fuel of the Future" Using Just Carbon Dioxide and Water

Of that, its 1.4 litre turbo-charged diesel engine weighs about 90kg.

The engine, of course, being only part of the drivetrain components that can be eliminated by a switch to electric drive. Transmission, radiator, all fluids, fuel, the whole exhaust system, etc. In some designs you can even replace the driveshaft. You basically gut 90% of the moving parts.

The fuel tank holds about 42 litres of diesel weighing... whatever that weighs.

About 30 kilos.

It can do 600 miles urban or ~700 miles motorway, driving normally.

And that spec is relevant why? No seriously, please tell me. In what sort of realistic scenario is it critical to be able to drive for 700 miles nonstop without ever setting foot out of your car? How can you even do that? Do you not pee? Do you not eat? Even if you could it's not safe to drive that long nonstop, a person is supposed to take regular rest breaks. You stop for lunch, you plug your car into a fast charger, and you go off on your way afterwards.

The reason gas and diesel cars have such huge tanks has nothing at all to do with that being some sort of remotely practical requirement. It's to minimize a great inconvenience of ICE vehicles, that is, how often you have to go out of your way in your daily life at regular intervals in whatever weather it is and stand outside pumping fuel into your car. In your daily life, you never have to do this with EVs. Not once.

The longest range electric car that I can actually touch right now is the Tesla Model S; It's 3 times the size of my car, weighs over twice as much and has a third of the mileage, and costs 10x as much.

Really, we're going to compare a brand new luxury sports sedan with a used family car? That's the comparison we're going for? Have you tried comparing your car with a Bugatti Veyron?

Comment: Re:With the best will in the world... (Score 1) 370

by Rei (#49564607) Attached to: Audi Creates "Fuel of the Future" Using Just Carbon Dioxide and Water

Slow down there. You're comparing the complete-cycle efficiency for petroleum to just the end-stage efficiency for electric.

You seem to have not noticed what this article is about. It's about making fuel from electricity and then giving it to cars. Both sides start with the same feedstock: electricity. So it doesn't matter how efficient the electricity was to make because it affects both paths equally.

But let's switch back to your "scenario that I want to talk about that's not the one in the article"

Slow down there. You're comparing the complete-cycle efficiency for petroleum to just the end-stage efficiency for electric. That electricity needs to be made somehow. Toss in 40% efficiency for coal plants (we'll leave out pumping/mining and fuel transport costs for now, assuming they're similar for oil and coal), battery charging efficiency of about 75% [futurepundit.com] (discharge efficiency is unspecified, but since the EPA mileage estimates are based on battery capacity it's safe to ignore it), and the 85% motor efficiency you've specified, and suddenly your EV is .4*.75*.85 = 25.5% efficient. Same as a diesel.

I don't see that figure in your link, and I don't really need your link because I'm familiar with the numbers already. It depends on what you mean by "charging efficiency". The US grid averages about 8% distribution losses, plant to breaker. Li-ions are over 99% efficient at slow charging, but depending on the type can drop a few percent in faster charging scenarios, and in an extreme situation down to the lower 90%s. The charger itself has some losses, if I recall correctly from the breaker they're usually 92-94% efficient. So a good middle of the road number is more like 84%.

Also note that EVs automatically also function as hybrids: they regen and don't "idle".

Their EV is cheaper to operate not because the EV is more energy-efficient, but because coal is so much cheaper than gasoline

Coal is of course the dirtiest widely used power source, and its usage is declining in most first-world countries. Natural gas and wind have the highest growth rates. The most efficient combined cycle natural gas plants are upwards of 60% efficient, although that's not an "average" efficiency, but even old plants are generally over 40%. Efficiencies on things like wind, solar, etc are of course not particularly meaningful, since you're not burning a fuel. Nuclear has a low efficiency, but again, that's not particularly meaningful.

Even putting solar panels on your roof and amortizing the costs in most climates makes running an EV cheaper than gasoline. It's not because coal is somehow ridiculously cheap. It's because oil is a really expensive energy source per joule.

Wind is only about twice the costs of coal

If this was true, people would be churning out new coal plants, not wind farms.

Comment: Re:danger vs taste (Score 1) 478

by Rei (#49564477) Attached to: Pepsi To Stop Using Aspartame

No, it doesn't break down in the stomach. It breaks down in the small intestine. Very, very rapidly, leaving no detectable levels in the blood,.

The most recent study I read was in 2008 or so (and yes, I read the entire thing)

You read one study among the hundreds on one of the most highly studied food additives in history? Great, let me know when you're done with the others. ;) And I'm sure there was zero selection bias in your choice of which of the many studies to read ;)

Wikipedia covers the "cancer" thing well enough for a primer:

Reviews have found no association between aspartame and cancer. These reviews have looked at numerous carcinogenicity studies in animals, epidemiologic studies in humans, as well as in vitro genotoxicity studies. These studies have found no significant evidence that aspartame causes cancer in animals, damages the genome, or causes cancer in humans at doses currently used.[8][38][41] This position is supported by multiple regulatory agencies like the FDA[58] and EFSA as well as scientific bodies such as the National Cancer Institute.[47]

Concern about possible carcinogenic properties of aspartame was originally raised and popularized in the mainstream media by John Olney in the 1970s and again in 1996 by suggesting that aspartame may be related to brain tumors. Reviews have found that these concerns were flawed, due to reliance on the ecological fallacy[59] and the purported mechanism of causing tumors being unlikely to actually cause cancer. Independent agencies such as the FDA and National Cancer Institute have reanalyzed multiple studies based on these worries and found no association between aspartame and brain cancer.[41]

As discussed in the article on controversies around aspartame, the Cesare Maltoni Cancer Research Center of the European Ramazzini Foundation of Oncology and Environmental Sciences released several studies which claimed that aspartame can increase several malignancies in rodents, concluding that aspartame is a potential carcinogen at normal dietary doses.[60][61] The EFSA[62] and the FDA[58] discounted the study results due to lack of transparency and numerous flaws in the study, finding no reason to revise their previously established acceptable daily intake levels for aspartame.

Comment: Re:danger vs taste (Score 1) 478

by Rei (#49564405) Attached to: Pepsi To Stop Using Aspartame

This is a strange post.

1) How does this have anything to do with anything that I wrote?

2) How is this anything but agreeing with what I wrote, that it's the concentration of the methanol that matters? (note: it's a myth that only methanol causes hangovers; ethanol does also, although methanol is far worse per unit mass)

3) Methanol poisoning can be acute or chronic. A couple shots of spirits containing 10-20% methanol can cause serious optic nerve damage in one sitting. A few shots of pure methanol can kill you in one sitting.

And yes, I know how one distills liquer. :) While there's no exact rules, a general approach is to toss off anything that has a "chemical" smell (which doesn't come from methanol, but from acetone, which has a fairly similar boiling point to methanol, nearly as high), recycle anything that has a "fruity" smell (ethyl acetate, which has a boiling point very similar to ethanol and much higher than that of methanol), and keep only that which smells only like alcohol. Methanol of course also smells like alcohol but the lower boiling point leads it to get mainly tossed from the first cup.

There's also a home test one can do for methanol if you want to be really sure - you expose it to an oxidizer, such as potassium dichromate with sulfuric acid. Ethanol oxidizes to fruity-scented acetylaldehyde while methanol oxidizes to foul, pungent formaldehyde which is a very easy scent to detect even in small quantities. But that's really not necessary with proper distilling.

Comment: Re:danger vs taste (Score 1) 478

by Rei (#49564287) Attached to: Pepsi To Stop Using Aspartame

Here, you can prove me wrong right now in just a couple weeks. We'll work on the honor system! Maintain a strict calorie count every day for the next four weeks, and do a good estimate of your caloric burn by standard formulae. Consume say 500 calories less every day than you burn. Weigh yourself before and after on an accurate scale under the same conditions (clothing, time of day, etc) - perhaps the average of a couple days of weighings at the beginning and end. Come back and tell me the results. If you didn't lose weight, I'll take you at your word and post an apology. How does that sound?

You realize that this "experiment" has been done again and again and time again, right?

Comment: Re:danger vs taste (Score 1) 478

by Rei (#49564269) Attached to: Pepsi To Stop Using Aspartame

" They have benefits for weight control because they help control appetite and delay hunger".

Funny, it's almost like I didn't write "Some routes may be easier to take than others, reducing cravings and the like."

getting a little regular exercise makes a huge impact on weight loss

Yes, that would be the "calories out" part of where I wrote "amount of calories in versus the amount of calories out".

It almost seems like you're having a debate with someone else.

Count your calories and estimate your calorie burn every day and make sure that you maintain a higher burn rate than consumption rate. And you will lose weight - it's really that simple. Yes, eating a lot of simple carbs and sugars will make you hungrier and sleepier - I never said it wouldn't. But that doesn't change how weight loss works. It's still "in" vs. "out".

Comment: Re:danger vs taste (Score 1) 478

by Rei (#49564225) Attached to: Pepsi To Stop Using Aspartame

Metabolism has been studied. It does not vary that greatly between individuals with the same activity levels. I seriously recommend that if you want to follow up your anecdote, you do actual calorie counts over a several week period between yourself and your roomate and keep track of walking distances and other forms of athletic activity. Then bring your actual data here and try to prove all of the science wrong with your two datapoints.

Comment: Re:danger vs taste (Score 1) 478

by Rei (#49564187) Attached to: Pepsi To Stop Using Aspartame

Your body cannot "make" you eat something. You have a brain. Different diets can cause different cravings and you may not have the willpower to override your cravings, but that's your own problem.

The facts are facts: weight loss is a matter of calories in vs. calories out, and you absolutely can lose weight eating twinkies. More to the point, this professor did it as a demonstration of this fact (he took a multivitamin, ate some celery, etc to make sure he got his essential nutrients, but the vast majority of his calories came from twinkies and other junkfood).

Comment: Re:With the best will in the world... (Score 3, Informative) 370

by Rei (#49562355) Attached to: Audi Creates "Fuel of the Future" Using Just Carbon Dioxide and Water

Saying "Now design a battery that can pull a 440,000 pounds or 200,000 kilograms triple trailer configuration across hundreds of miles of highway. " is silly, that's like saying "Now design a gas tank that can pull a 440,000 pounds or 200,000 kilograms triple trailer configuration across hundreds of miles of highway. " Batteries don't haul loads, electric motors do. And electric motors have far more power per unit mass and per unit volume than gasoline. Here's a comparison between a gasoline car engine and an equivalent power electric motor.

The heaviest haul vehicles *do* use electric drive. The vast majority of trains today, for example, are electric drive, and increasingly large haul trucks are switching to electric drive. The electric drive however is generally driven by either diesel generators or direct grid power to save the cost of having to buy batteries. Due to the battery cost, the largest ones out there re things like BYD's 60 foot / 120 passenger jointed bus and several models of 15-30 tonne haul trucks. The economics just aren't there for road trains like you're talking about at this point. It's not a tech issue, it's a battery cost issue.

Supplying the power is easy. Just thinking about it from a practical standpoint. These are batteries that can fast charge in half an hour or so. Discharging is generally easier on batteries than charging. But let's just say half an hour discharge. Li-ions now get up to a couple kilowatts per kilogram, but are only a couple hundred Wh/kg at best in terms of energy density. A road train may require something like 1000hp. That's 750kW electric. Actually less because you get a smoother torque curve, but let's ignore that. That's about 375kg of good li-ion batteries to be able to provide the needed power. Let's double that for poorer batteries, and add a bunch more for inefficiencies... let's go full overkill and say we need 1000kg of batteries to provide the needed power. 1000kg of batteries would hold about 200kWh of electricity. That's only 80 miles of range. Which is way less than you'd practically need for a road train.

That is to say, even with the most pessimistic look at it, even a pathetically under-ranged road train would have way more power than needed to run its engine. The more batteries you add, the more power becomes available. Power density is essentially a non-issue when dealing with li-ions.

Also look at aviation, liquid fuel is going to be the practical choice far into the future.

Aviation is the highest-hanging fruit, but it's still a fruit that is within reach, and the small-scale electric prop plane market has gone from almost nonexistent to rapidly growing in the past 5 years or so. And there's lots of transitional techs, such as driving the compressor with electricity, which allows you to get rid of the turbine and thus increasing engine power and efficiency while reducing part count and maintenance.

The motors and batteries also require rare earths with are in short supply and require massive mining operations to supply.

False. First off, only permanent magnet motors require rare earths. Most modern EVs, like Tesla's offerings, don't use permanent magnets. Secondly, lithium-ion batteries do not use rare earths; I don't know where you got this idea. Lastly, rare earths aren't actually rare. China dumped the market, pushing other producers out of business, and then suddenly started holding back production for domestic uses, creating a temporary glut, but it's already started resolving itself.

An it's just not a matter in installing fast chargers, widespread adoption would require an overhaul in the electric grid.

This is once again false but I've already lost enough interest in this conversation to have to dig up research papers for you, so I'm just going to tell you "Google It". There've been many studies, every region in the US except the Pacific Northwest already has the generation capacity, as well as the distribution capacity, excepting the "last hop" in residential areas (neighborhood grids). But that'd only be an issue if everyone magically switched over instantly, it presents no threat to any realistic adoption rate.

EVs are inherently grid stabilizers. Utilities love them. They charge mainly at night, when demand is way down and power plants have to sit idle, and they're predictable, steady loads. Utility companies are some of the biggest EV proponents out there. Smart charging (which, BTW, doesn't inherently require outflow, just changes in the rate of inflow) is just an extra.

Comment: Re:Since when (Score 1) 478

by Rei (#49561953) Attached to: Pepsi To Stop Using Aspartame

Let me take a wild guess that the hospital said he was a-okay.

People with phenylketonuria are not that hypersensitive to drinks containing aspartame. Protein-rich foods is usually more challenging to deal with since they're harder to avoid and can provide more phenylalanine. And the condition is not an immediate reaction like a food allergy, it's an accumulative problem. There's no way drinking a diet soda should have landed him in the hospital.

I have a strong suspicion that this person was like 90% of "gluten intolerant" persons: a self-diagnosed hypochondriac.

Comment: Re:danger vs taste (Score 1) 478

by Rei (#49561817) Attached to: Pepsi To Stop Using Aspartame

at a bare minimum they are less likely to eat some of your food.

Gut bacteria are not "eating your food", they're making food for you. They consume that which your body was not able to break down (such as some types of starches and sugars) and produce things that the body can absorb, like short chain fatty acids. Rodent studies show that if you kill all of a rat's gut flora with antibiotics that they have to consume about 30% more calories to maintain the same weight.

If gut bacteria were consuming significant amounts of our calories we would have long ago evolved to fight them off. They help us get more calories from our food.

Nothing succeeds like excess. -- Oscar Wilde

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