bhauth
cancer rates after gene therapy
some questionable space launch guns
https://en.wikipedia.org/wiki/Chlorhexidine#Side_effects
It can also obviously break down to 4-chloroaniline and hexamethylenediamine. Which are rather bad. This was not considered in the FDA’s evaluation of it.
If you just want to make the tooth surface more negatively charged...a salt of poly(acrylic acid) seems better for that. And I think some toothpastes have that.
EDTA in toothpaste? It chelates iron and calcium. Binding iron can prevent degradation during storage, so a little bit is often added.
Are you talking about adding a lot more? For what purpose? In situations where you can chelate iron to prevent bacterial growth, you can also just kill bacteria with surfactants. Maybe breaking up certain biofilms held together by Ca? EDTA doesn’t seem very effective for that for teeth, but also, chelating agents that could strip Ca from biofilms would also strip Ca from teeth. IIRC, high EDTA concentration was found to cause significant amounts of erosion.
I wouldn’t want to eat a lot of EDTA, anyway. Iminodisuccinate seems less likely to have problematic metabolites.
on bacteria, on teeth
You can post on a subreddit and get replies from real people interested in that topic, for free, in less than a day.
Is that valuable? Sometimes it is, but...not usually. How much is the median comment on reddit or facebook or youtube worth? Nothing?
In the current economy, the “average-human-level intelligence” part of employees is only valuable when you’re talking about specialists in the issue at hand, even when that issue is being a general personal assistant for an executive rather than a technical engineering problem.
Triplebyte? You mean, the software job interviewing company?
-
They had some scandal a while back where they made old profiles public without permission, and some other problems that I read about but can’t remember now.
-
They didn’t have a better way of measuring engineering expertise, they just did the same leetcode interviews that Google/etc did. They tried to be as similar as possible to existing hiring at multiple companies; the idea wasn’t better evaluation but reducing redundant testing. But companies kind of like doing their own testing.
-
They’re gone now, acquired by Karat. Which seems to be selling companies a way to make their own leetcode interviews using Triplebyte’s system, thus defeating the original point.
-
Good news: the post is both satire and serious, at the same time but on different levels.
Here are some publicly traded large companies that do a lot of coal mining:
Coal India did pretty well, I guess. The others, not so much.
Nice post Sarah.
If Alzheimer’s is ultimately caused by repressor binding failure, that could explain overexpression of the various proteins mentioned.
in short, your claim: “The cost of aluminum die casting and stamped steel is, on Tesla’s scale, similar” both seems to miss the entire point and run against literally everything I have seen written about this. You need citations for this claim, I am not going to take your word for it.
OK, here’s a citation then: https://www.automotivemanufacturingsolutions.com/casting/forging/megacasting-a-chance-to-rethink-body-manufacturing/42721.article
Here I would be careful since investments, especially in a particular model generation of welding robots, are depreciated. For forming processes, the depreciation can even extend over three or four model generations. This technological write-off – bear in mind that this is not tax-related – runs over a timeframe of 30 years. For the OEMs that are already using these machines for existing vehicle generations, the use of the new technology makes no sense. On the other hand, thanks to its greenfield approach, Tesla can save itself these typical investments in shell-type construction. In a brownfield, it would be operationally nonsensical not to keep using long depreciated machinery. So, in this situation, I would not support the 20-30% cost savings that were cited.
With die casting, one important aspect is that there is a noticeable reduction in the service life of the die-casting moulds. Due to so-called thermal shock, the rule of thumb is that a die-casting mould is good for 100,000-150,000 shots. By contrast, one forming tool is used to make 5m-6m parts. So, we are talking about a factor of 20 to 30. There is quite clearly a limited volume range for which the casting-intensive solution would be appropriate. To me, aluminium casting holds little appeal for very small and very large volumes. Especially for mass production in the millions, you would need about six or seven of these expensive die-casting moulds. We estimate that the die-casting form for the single part, rear-end of a Tesla would weigh about 80-100 tonnes. This translates to huge costs for handling and the peripheral equipment, in the form of cranes, for example. Die-casting moulds also pose technological obstacles and hazards. The leakage of melted material is cited as one example. The risks of not even being able to operate in some situations are not negligible.
Or the geometry of the frame was insufficiently optimized for vertical shear. I do not understand how you reached this conclusion.
No. If aluminum doesn’t have weak points, it stretches/bends before breaking. The Cybertruck hitch broke off cleanly without stretching. Therefore there was a weak point.
By nothing I mean that the estimate for their marketing spend in 2022 (literally all marketing to include PR if there was any at all) was $175k.
I’m skeptical of that. PR firms don’t report to Vivvix.
Here are the costs from the above link:
It’s worth noting that countries (such as India) have the option of simply not respecting a patent when the use is important and the fees requested are unreasonable. Also, patents aren’t international; it’s often possible to get around them by simply manufacturing and using a chemical in a different country.
The only advantage DDT has over those is lower production cost, but the environmental harms per kg of DDT are greater than the production cost savings, so using it is just never a good tradeoff.
As I said, if DDT was worth using there, it was worth spending however much extra money it would have been to spray with other things instead. If it wasn’t worth that much money, it wasn’t worth spraying DDT.
And regarding “environmental harms,” from personal experience scratching myself bloody as a kid from itchy bites after going to the park in the evening, I would extinct a dozen species if mosquitoes went down with them.
The biggest problem with DDT is that it is bad for humans.
While I still disagree with your interpretation of that post, I don’t want to argue over the meaning of a post from that blog. There are actual books written about the history of titanium. I’m probably as familiar with it as the author of Construction Physics, and saying A-12-related programs were necessary for development of titanium usage is just wrong. People who care about that and don’t trust my conclusion should go look up good sources on their own, more-extensive ones.
If it wasn’t for the A-12 project (and its precursors and successors), then we simply wouldn’t be able to build things out of titanium.
That is not an accurate summary of the linked article.
In 1952, another titanium symposium was held, this one sponsored by the Army’s Watertown Arsenal. By then, titanium was being manufactured in large quantities, and while the prior symposium had been focused on laboratory studies of titanium’s physical and chemical properties, the 1952 symposium was a “practical discussion of the properties, processing, machinability, and similar characteristics of titanium”. While physical characteristics of titanium still took center stage, there was a practical slant to the discussions – how wide a sheet of titanium can be produced, how large an ingot of it can be made, how can it be forged, or pressed, or welded, and so on. Presentations were by titanium fabricators, but also by metalworking companies that had been experimenting with the metal.
That’s before the A-12.
In 1966, another titanium symposium was held, this one sponsored by the Northrup Corporation. By this time, titanium had been used successfully for many years, and the purpose of this symposium was to “provide technical personnel of diversified disciplines with a working knowledge of titanium technology.” This time, the lion’s share of the presentations are by aerospace companies experienced in working with the metal, and the uncertain air that existed in the 1952 symposium is gone.
At that point, the A-12 program was still classified and the knowledge gained from it was not widely shared.
on Science Beakers and DDT
I had an interview with one of these organizations (that will remain unnamed) where the main person I was talking to was really excited about a bunch of stupid bullshit ideas (for eg experimental methods) that, based on their understanding of them, must have come from either university press releases or popular science magazines like New Scientist. I was trying to find a “polite in whatever culture these people have” way to say “this is not useful, I’d like to explain why but it will take a while, here are better things” but doing that eloquently is one of my weak points.
From what I’ve seen of the people there, ARPA-E has some smart people (“ordinary smart”, not geniuses) but the ARPAs are still very tied to the university system, with a heavy reliance on PhD credentials.
I think the basic idea of using more steps of smaller size is worth considering. Maybe it reduces overall drift, but I suspect it doesn’t, because my view is:
Models have many basins of attraction for sub-elements. As model capability increases continuously, there are nearly-discrete points where aspects of the model jump from 1 basin to another, perhaps with cascading effect. I expect this to produce large gaps from small changes to models.
As you were writing that, did you consider why chlorhexidine might cause hearing damage?