> The metal concentrations varied by where the tampons were purchased (US vs. EU/UK), organic vs. non-organic, and store- vs. name-brand. However, they found that metals were present in all types of tampons; no category had consistently lower concentrations of all or most metals. Lead concentrations were higher in non-organic tampons but arsenic was higher in organic tampons.
>
> Metals could make their way into tampons a number of ways: The cotton material could have absorbed the metals from water, air, soil, through a nearby contaminant (for example, if a cotton field was near a lead smelter), or some might be added intentionally during manufacturing as part of a pigment, whitener, antibacterial agent, or some other process in the factory producing the products.
(I read the source article relatively fast, not thoroughly but closer than 'skimmed')
Much is made of "measurable" and MDL (method detection limit) using a "using a PerkinElmer NexION 350S Inductively Coupled Plasma Mass Spectrometry with dynamic reaction cell (ICP-DRC-MS)".
Such equipment can almost count atoms.
Even before man idustrialised there were trace metals, toxic metals, to be found at measurable (with modern equipment) levels in the purest clear mountain streams (as water leached lead and other solubles from rocks, etc).
I'm not diminishing the problem here, there is a real danger from industrial by product landing on cotton fields and making its way to human skin .. but what's the baseline?
Do we have a study on raw cotton from various fields?
Australian cotton from Kimberley fields would likely have the least industrial addition of metals, how do such samples compare to cotton from fields adjacent to smelters, etc.
The laws of thermodynamics apply in closed systems, and our planet is not a closed system.
Solar power, geothermal power, hydro power, are effectively perpetual motion, for our purposes. Heat pumps kind of violate the "you can't get something for nothing" principle too, since you can get >100% return on the electricity you put into them. The more we look into renewables, the more we can find ways to "cheat" by using "preprocessed" goods where the sun or the earth already did the hard part for us.
There's no thermodynamic reason you couldn't have a small device on your desk that uses ambient heat, moisture, light, etc to store energy that you can use to do work, just engineering and chemical reasons it's hard to do this on a scale that's relevant. https://en.wikipedia.org/wiki/Crookes_radiometer is over 100 years old and, if kept in sunlight, can provide "perpetual motion" for "free".
> The laws of thermodynamics apply in closed systems, and our planet is not a closed system.
> Solar power, geothermal power, hydro power, are effectively perpetual motion, for our purposes.
I get solar power and hydro [also solar] power, but isn't geothermal power a closed part of the system? Where does solar input feature in that?
> The more we look into renewables, the more we can find ways to "cheat" by using "preprocessed" goods where the sun or the earth already did the hard part for us.
This is also a closed part of the system. If the argument you're making is "the planet is not a closed system", then you need to be using energy that comes from outside, not energy that is already contained in the system.
The sun is arguably ultimately responsible for geothermal. Even if geothermal is part of the closed system, it's still functionally perpetual motion for our purposes. The main argument I'm making is that perpetual motion* is, for all practical purposes, possible, as long as you're willing to be specific, and you're unconcerned with the heat death of the universe (none of us should be concerned with the heat death of the universe).
Corners are actually super effective at moving liquid using surface tension (assuming the contact angle is such that the surface is concave). The key is that at the front of the liquid, where it's very thin in the corner, the surface has a small radius of curvature => low pressure. If there's a lot of fluid filling up a corner, the radius of curvature is large => high pressure. So fluid naturally flows into the corner. This is used a lot in space applications, e.g., for propellant management devices [1].
The first analysis of the effect I know of is a paper by Concus and Finn (1969) [2], who realized that fluid can be carried arbitrarily high in a triangular groove, even against gravity, and proposed that trees may use this mechanism to carry water to their highest reaches. (The catch is that the fluid front becomes thinner and thinner as it gets higher. And it starts breaking down when it gets so thin that the continuum limit no longer applies).
If you like math, I'd highly recommend checking out Mark Weislogel's research [3] which deals with the dynamics of viscous flow in triangular grooves.
Shameless plug: chapter 4 of my Ph.D. thesis [4] gives an introduction to the subject.
Fluid flows/sticks more easily along the sharp seam than the rounded corners. So there is always a little bit close to that sharp focus point near your lips. You slurp/sip from that sharp point, drawing more fluid along the seam.
But, for exactly the same reasons, this thing is probably a pain to clean. Sharp corners and cleaning don't mix. That narrow seam will likely become caked in the dried residue of a hundred previous drinks. Even in an earth dishwasher, soap scum would be difficult to rinse out. I suspect these are not used many times.
> But, for exactly the same reasons, this thing is probably a pain to clean.
I dunno, given the size I imagine a regular toothbrush could dislodge anything dried, and small sponge-on-a-stick could get it acceptably dry.
It's also worth asking what it might replace: On the ISS do they clean any drink-pouches, or are they all treated as disposable? I imagine that they become trash, since the next drink (or dehydrated drink-to-be) was probably already shipped in its own flattened pouch.
> That narrow seam will likely become caked in the dried residue of a hundred previous drinks
On the other hand, without gravity there is convection, which means those corners probably don't dry out as quickly. If I'm right about that then rinsing left-over residue out with plain water is easier if you don't wait too long.
How gorgeous! It's hilarious how yonic it appears when looking down upon the brim.
I think it works because the narrowing channel has increasing surface area to volume ratio, as you proceed toward the spout, so the capillary forces pull along a gradient toward the spout, gently tugging the liquid toward it.
The bowl of the cup is lightly pinched around the brim to provide a kind of barrier to prevent the globule of zero-g liquid from just floatin' away! Hahaha :)
They say in the article that capillary action draws the coffee along the narrow edge. This is aided by surface tension, just like how water is drawn into a capillary tube.
Same in the west slope of Colorado. So much water is used to grow alfalfa, in part because there is a “use it or lose it” water rights policy:
> Failure to apply a water right to beneficial use when water was available for a period of ten or more years results in a rebuttable presumption of abandonment.
This leads to huge amounts of wasted water and alfalfa growing.
Man this fact just points so heavily to a natural part of human nature. If we're given more than we need, but are threatened to lose some or all of it if we don't use it, we'll find ways to use it whether we need it or not. Seems like it's also human nature to make those threats.
I gave it this prompt, which I didn't spend any time refining, and it came up with a world that does a pretty good job of matching it.
> A world made of very strong rock that has lots of rain. The rain contains acid, which wears the rock down. There is lots of soil, but it s in very thin layers because the world is relatively new.
I prompted it "small heavily forested islands in rough seas" and it gave me one large forested land area in snow, with a bunch of rocky treeless islands in calm water. <shrug>
This article doesn’t really address statistics for younger people. I feel like the headline should be: should elderly people be given CPR? For me the answer is a strong no. Why on Earth would you give CPR to a 90-year old person!?
> survival after out-of-hospital CPR dropped from 6.7% for patients in their 70s to just 2.4% for those over 90
