Cheap Gel Film Pulls Buckets of Drinking Water Per Day From Thin Air (newatlas.com) 93
Researchers at the University of Texas at Austin have now demonstrated a low-cost gel film that can pull many liters of water per day out of even very dry air. New Atlas reports: The gel is made up of two main ingredients that are cheap and common -- cellulose, which comes from the cell walls of plants, and konjac gum, a widely used food additive. Those two components work together to make a gel film that can absorb water from the air and then release it on demand, without requiring much energy. First, the porous structure of the gum attracts water to condense out of the air around it. The cellulose meanwhile is designed to respond to a gentle heat by turning hydrophobic, releasing the captured water.
In tests, the gel film was able to wring an astonishing amount of water out of the air. At a relative humidity of 30 percent, it could produce 13 L (3.4 gal) of water per day per kilogram of gel, and even when the humidity dropped to just 15 percent -- which is low, even for desert air -- it could still produce more than 6 L (1.6 gal) a day per kilogram. [...] And the new gel film's efficiency could be improved even further, the team says, by creating thicker films, absorbent beds, or other array formations of the material. Perhaps most importantly, the material is extremely inexpensive to produce, costing as little as $2 per kilogram. The research was published in the journal Nature Communications.
In tests, the gel film was able to wring an astonishing amount of water out of the air. At a relative humidity of 30 percent, it could produce 13 L (3.4 gal) of water per day per kilogram of gel, and even when the humidity dropped to just 15 percent -- which is low, even for desert air -- it could still produce more than 6 L (1.6 gal) a day per kilogram. [...] And the new gel film's efficiency could be improved even further, the team says, by creating thicker films, absorbent beds, or other array formations of the material. Perhaps most importantly, the material is extremely inexpensive to produce, costing as little as $2 per kilogram. The research was published in the journal Nature Communications.
Forgot the most important.. (Score:4, Funny)
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The single most important factor of this process is the energy consumed per liter of water produced ... which TFA doesn't even mention.
Reliable heuristic: When new technology announcements omit critical information, they can be dismissed as meaningless hype.
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Not only the article - the paper linked in the article also fails to mention how much energy is used.
https://www.nature.com/article... [nature.com]
It just says that the gel will start to release water when heated above 45C, and that they used 60C @20% relative humidity to release the water from the gel fully, but since the gell spontaneously absorbs water at ambient temperature, it is likely that absorption is an exothermic process and adsorption (ie release of the water) is therefore endothermic, requiring the absorpti
Re:Forgot the most important.. (Score:5, Insightful)
This is how patents work. Let the original inventor make some money from their invention, but only for a limited time (20 years in the US). After that, the invention becomes public domain, and can "benefit humanity" without commercial restrictions.
Every useful invention serves the "betterment of humanity." Why is this particular invention one that shouldn't be monetized?
In terms of history, 20 years isn't very long.
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This is how patents work. Let the original inventor make some money from their invention, but only for a limited time (20 years in the US). After that, the invention becomes public domain, and can "benefit humanity" without commercial restrictions.
Every useful invention serves the "betterment of humanity." Why is this particular invention one that shouldn't be monetized?
In terms of history, 20 years isn't very long.
Truly innovative inventions (like this appears to be)? Absolutely makes sense to protect the inventor for a limited time (20 years might be much, depending on the type of invention*). Also, there is the ability to file for a 5 year exemption in the US (last I checked).
Patents like medicinal patents where they discover a drug that does something almost identical to another but from just the slightest different attack vector, while still having all the same problems, but magically is considered innovative?
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You're right that patents are often abused, such as patenting something with a change of color. There's a simple solution though: don't make your copy the newly patented color!
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"In terms of history, 20 years isn't very long."
So what?
In terms of geology a million years is nothing at all.
In terms of a human life 20 years is typically between 1/3 and 1/4.
All tech innovations have to be able to build on the tech that came before. So fans of the current patent system are advocating for each of us only getting to see 3 or maybe 4 levels of improvement before we croak.
Surely most ideas either aren't really such a big deal in the first place or can be turned into a worthwhile profit in fa
Re: Forgot the most important.. (Score:2)
Patented technologies, applications, etc are available for others to use, if the patent owner allows it - many/most patents are available for license, that's how independent investors feed their families.
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Independent investors aren't inventing anything and aren't building anything.
The patent trolls give someone an idea (often an obvious one that doesn't deserve a patent) a one time payment because that person knows they couldn't possibly afford all the lawyers and legal fees that would be required to defend the patent themselves.
Then the patent sues anyone who has the same idea and tries to actually make a product.
Should the troll offer a license, and should the maker manage to discover this patent even exis
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And how many projects to benefit humanity have been squashed even before they were conceived because the monetization equation doesn't take the benefit to humanity into account other than how much currency it moves?
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The value of something is defined by how much people are willing to pay for it. If an invention is useful, people will pay for it. If an inventor imagines that his invention is valuable, but can't sell it, that might be an indication that others don't see the same value in it that the inventor does. So most of those "squashed" ideas probably should be squashed.
What about poor people who can't afford to pay? It's true that they won't benefit from new inventions immediately, the cost will be prohibitive. But
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I don't think "useful" is the correct word. I think "profitable" fits reality. If in invention can be made profitable it will be made useful.
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Will it?
A paper clip is useful for many things, and I can make it profitable by selling it for more than it costs me to buy it. But if nobody uses paper anymore, then they will become useless regardless of how well I can build a profitable business around selling them.
With regards to getting water out of the air...this is yet another method of getting water for whatever you need it for. If I have access to running water, I don't need this invention. If I don't, then will I have better access to the special
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This proves the point. If you can sell it and make a profit then you've found a way to make it profitable. If you couldn't you'd just sit on it even if there were a huge secondary benefit to society that couldn't be monetized.
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I would argue that a "benefit to society" that can't be monetized...isn't really a benefit.
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So you think, for example, a medicine to help third world countries isn't worth it if it can't be monetized? I think maybe you're looking too much from a first world perspective.
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I don't insist that something beneficial be monetized in every situation. In your example, the medicine CAN be monetized in countries where there is wealth. Its value is proven by the fact that those who can pay, will do so. Charitable contributions are an important part of what makes us human. I personally give my time and money to work with young people who are in poverty, teaching them trade skills, paying for the supplies myself. Doing so not only helps them, but makes me a better person.
However, we con
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There are many drugs and drug patents that sit on shelves because they're only useful in third world countries but not in first world countries. If first world countries don't have that problem then there's nobody to subsidize the third world.
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Can you name one example? I'm interested.
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Antibiotics and antibiotic research is the most widely cited example. A couple internet searches should bring you to enough links to keep you reading for hours.
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How are antibiotics specific to the "third world"? Antibiotics are used--and paid for--everywhere. Antibiotic research is needed--and paid for--in the "first world" because older antibiotics are gradually losing their effectiveness.
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Yes, antibiotics are needed and used everywhere. However, research was shelved for more than 15 years because only third world countries had great needs for anything new and there wasn't first world money going into antibiotics. Money trumped the needs of the poor. I'm guessing you didn't read any of the dozens of articles found by searching. This money over people and lack of research is exactly why we have all the difficult to treat "antibiotics of last resort" bacterial infections in first world counties
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Re: Forgot the most important.. (Score:2)
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Are you sure it's worth "all you have" for an extra month of life?
Do you smoke? Do you drink? These are known to reduce your lifespan by more than a month. Is it work enough to you to stop these, cold turkey, for the rest of your life?
What about exercise? Do you get enough? We know that proper diet and exercise increase one's chance for a longer life. Do most people do these things religiously? Nope.
So no, I don't buy the argument that another month of life is worth "all you have."
In any case, we aren't tal
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That depends. If I'm dying of cancer and in pain, probably not a whole lot. If I'm healthy and happy, then I'd certainly want that.
What does "another month of life" have to do with the invention of a way to get water out of the air? This invention isn't going to add another month of life for anybody. And it's not the only option. A far more practical option (today) is something like this: https://lifewater.org/blog/dri... [lifewater.org]
You are welcome to spend your own money on it (Score:2)
And how many projects to benefit humanity have been squashed even before they were conceived because the monetization equation doesn't take the benefit to humanity into account other than how much currency it moves?
If you think that some invention is so important to the welfare of humanity, or some subset of it, that it should be rolled out despite its unprofitability as a product, you are welcome to spend your own money to make up the difference.
You are also welcome to found a charity to collect enough lik
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yes it does, just very limited number of them
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FTFA:
The gel is made up of two main ingredients that are cheap and common – cellulose, which comes from the cell walls of plants, and konjac gum, a widely used food additive. ...Making the gel is also fairly simple, the team says. The basic ingredients are mixed together then poured into a mold, where it sets in two minutes. After that it’s freeze-dried, then peeled out of the mold and ready to get to work.
Allow me to help you pull water out of the air.
Freeze Drier [youtube.com]
Cellulose [alibaba.com]
konjac gum [alibaba.com]
Desert humidity (Score:5, Informative)
Re:Desert humidity (Score:5, Insightful)
In other words: Phoenix is an utterly insane place to build a city.
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I once had a stop in Tuscon to pick up passengers so I didn't have to deplane. The captain said the locals couldn't play golf because it was so hot the glue that held the grips on the club shafts was melting and clubs were flying out of folks hands.
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Good grief, why would you even attempt to play golf in such weather?
Re:Desert humidity (Score:4)
Phoenix is an utterly insane place to grow a lawn. But if you are happy with a rock and cactus garden, it's okay.
There's plenty of solar energy to run the AC.
Average humidity in Phoenix. Solar to pump air. (Score:2)
Seems as though the solar energy solves many problems.
The solar energy could pump lots of air through the film used to remove the water.
Would the water produced from the film be polluted by air pollution? It seems that it would.
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Phoenix is an utterly insane place to grow a lawn. But if you are happy with a rock and cactus garden, it's okay.
There's plenty of solar energy to run the AC.
Does solar energy deliver drinking water too?
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So you need to spend 10 bucks instead of 4 to water your family in an emergency. Yeah, that's absolutely useless to anyone on the planet right there.
I get what you're saying by your logic, airplanes are fucking useless because I am afraid of heights.
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Re:Desert humidity (Score:4, Informative)
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Grass? You know they grow corn in Phoenix right? Lots of it right next to the Goodyear airport.
Relative humidity [Re:Desert humidity] (Score:2)
"At a relative humidity of 30 percent, it could produce..."
This statement is nearly meaningless. Relative humidity is the wrong measure, since the amount of water in the air is proportional to the absolute humidity, not the relative humidity.
If the temperature is low, it's not going to produce that amount of water, because there simply is not that much water in the air to produce.
Re:Relative humidity [Re:Desert humidity] (Score:5, Informative)
No, RH is the right measurement, because relative humidity is more or less proportional to the water vapor's partial pressure, which speaks to how hard it is to collect.
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No, RH is the right measurement, because relative humidity is more or less proportional to the water vapor's partial pressure,
No, absolute humidity is proportional to the water vapor's partial pressure. Relative humidity is absolute humidity divided by saturated vapor pressure, which is an exponential function of temperature.
40 percent relative humidity represents twice as much water in the atmosphere at 30C as at 20C.
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up to 30% during the wee hours.
That's the wrong kind of humidity...
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Weirdly lacking in details... (Score:5, Informative)
I mean, this sentence alone raises a few eyebrows;
"The desorption is performed at 7.5% RH, 60âÂC"
So you have a salt matrix gel that absorbs water really well, but getting the water out of it seems a bit more of a challenge. No such thing as a free lunch; having a substance that's really good at absorbing moisture isn't particularly good for moisture harvesting when it's really difficult to recover that water as water (e.g. consider Phosphorus pentoxide as a desiccant... really powerful but not at all useful for water recover). May as well put that effort into other methods that give you water more directly.
Anywho, seems the test conditions are 25C at 15% and 30% RH. Going with the more generous 30% number; That's a humidity ratio of 0.00589 (kg of water per kg of air) at sea level. With a specific volume of 0.85 cubic meters per kg of dry air, that's 0.00500 kg of water per cubic meter. 5 grams. I'm not seeing any mention of how dry the air coming out of their test setup is? Like, okay it can absorb a good amount of moisture per gram of its own mass, and a good amount per hour, but that's not the full story; How many thousands of cubic meters of air will I need to pump through my machine to fill a 1 liter bottle?
And the ultimate question; What's the total energy investment per liter of recovered water versus other methods?
=Smidge=
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A basic 120mm, low noise case fan like this one...
https://www.amazon.com/uphere-... [amazon.com] ...is rated at 38cfm, which is more than 1 m^3/minute. Your number of 0.005kg of water/m^3 of air is 5cc... so if this was 100% effective (which I'm sure it's not), then a 120mm case fan pulling air through a low back pressure folded box of this material would produce 1L of water in 200 minutes.
I'd guess it's only going to get 1/2-1/3 that amount out of the air, though. But that's also only a 0.12a 12v fan.
The energy input h
Re: Weirdly lacking in details... (Score:2)
Re:Weirdly lacking in details... (Score:4, Informative)
Sounds like it will make a badass dehumidifier if nothing else... if it is durable for sufficiently long periods. Right now the adsorption dehums use zeolites in a spinning wheel or drum that gets heated as it rotates towards the drain area. The zeolites last practically forever, are found in nature but are also cheap to make from ingredients not in any danger of running out, and are super stable.
I looked up konjac [wikipedia.org] and it seems it is notable in large part because of its durability, which causes jellies of the product to pose a greater choking risk than others because they don't readily dissolve in water. Also in my search results was a paper on konjac nanospheres [nih.gov] for timed drug release. Interesting glop. In the paper we're discussing though the konjac is said to provide greater porosity, increasing surface area.
Adsorption dehumidifiers are already being used to recover water from air, just literally the same thing you'd use to keep your closet dry scaled up. Zeolites are really, really cheap. Like, you can buy natural ones as horse stall freshener — horses have very sensitive respiratory systems so you can't use anything unsafe in that context. A 25 pound bag (of "sweet PDZ" branded clinoptilolite [wikipedia.org]) is $12.99 at tractor supply (on sale now for $10.99.)
The paper essentially claims that they have higher water uptake and lower energy demand than zeolites, which are actually already being used because they are cost-effective in some scenarios. If accurate then the only real questions are how cheap is it (should be pretty cheap) and how durable is it.
As for figuring out how much air you're going to have to process, they discuss their test methodology on pages 4 and 5, and they state just how much water they got out. That should be enough information to figure out how much air you're going to have to pump into the system...
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Mod parent up. I, too, was hoping this would turn out to be a good dehumidifier. If it's not one-time-use and uses less energy to cycle than a compressor, this is a pretty exciting find for wet places, too.
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I hope this helps answer a couple of your questions. Excerpted from the "Supplemental Materials" PDF [springer.com] with emphasis from me. (Also modified unit representation because goddamn Slashdot won't let us subscript.)
Outdoor water harvesting and collection experiment based on SHPF was conducted at University of Texas, Austin campus on March 12th, 2022 (Supplementary Fig. 18a). Six cycles were performed under the RH ranging from 10.6 to 41.6% (environmental temperature of 1.4-22.3C)
to achieve a water uptake of 0.43 to 0.90 g/g (Supplementary Fig. 18b). One cycle included 100 min sorption and 30 min desorption (including condensation and collection). The power supply of the heating plate was 3.38 W for a large SHPF sample to reach and maintain at 60C. The water vapor was condensed on the inner surface of glassware without vertical heating plates. The condensed water was collected using a pipette. The water production is 0.3-0.7 g water/g SHPF per cycle, corresponding to ~5.5 L/kg*day (11 cycles per day, RH 10.6%-41.6%). The thermal efficiency calculated from each cycle is 16%-22%, which is comparable to the reported experimental thermal efficiency and estimated thermal efficiency.
It doesn't say how many cubic meters of air you need because their system did not have any active air circulation. It's not like outside runs out of air.
On the other hand, I'm mildly annoyed that they don't say how much the SHPF in the sample weighed. They just extrapolate to say a kilogram of it will n
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A patch of this that is 1m square, with a piddly 1km/h breeze will filter through 1000 cubic maters per hour, or 24,000 cubic meters in a day. In your 0.005kg of water per cubic meter of air example, That is over 100kg of water going through a device at 30% RH, with the smallest of breezes.
Also, "The cellulose meanwhile is designed to respond to a gentle heat by turning hydrophobic, releasing the captured water." How gentle a heat? Capture water at night, release at the middle of a desert day? I wonder ho
How to lie in abstracts and get massive PR. (Score:5, Informative)
Reporters have then read cursoraliy the paper (or perhaps its PR material) and seen that it uses 'biomass' and 'salt'. They then do calculations, and come up at $2/kg, as is intended by the papers authors to get good PR.
However.
The salt mentioned is not table salt, but lithium chloride.
Lithium chloride - which makes up a half by weight of the film, and is also in obvious demand for batteries, is $70/kg or so in bulk.
Re: How to lie in abstracts and get massive PR. (Score:2)
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The authors' calculation of the cost per kg is $1.96 and is shown in supplementary table 3 (page 26 of the supplementary material linked from the main paper)
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Lithium chloride - which makes up a half by weight of the film, and is also in obvious demand for batteries, is $70/kg or so in bulk.
It's a film. The paper [nature.com] discusses a "thickness of ~100 μm" and the film is further porous and you can see from the SEM images also included in the paper that the film is mostly holes, i.e. the density is very low. In addition, "The SHPF consists of earth-abundant biomasses, konjac glucomannan (KGM), and hydro-xypropyl cellulose (HPC) as the hybrid polymer matrix to hold uniformly dispersed LiCl solution", i.e. the film is not entirely lithium chloride — indeed, it appears that the bulk of th
What's wrong with scientific research nowadays? (Score:3)
Re: What's wrong with scientific research nowaday (Score:2)
Like curved glass solar panels in a Silicon Valley Factory populated with singing robots [nbcbayarea.com]?
My basement (Score:3)
Drinking water? Phbbbb.
What about my basement? Running a dehumidifier for half the year really jacks up the electric bill.
"Buckets" ? (Score:2)
"Pulls Buckets of Drinking Water", really? 1 Gallon buckets, 5 gallon buckets? Why not just tell us how many football fields of water it pulls.
Re:"Buckets" ? (Score:4, Funny)
Minecraft buckets, obviously.
Have they built a prototype? (Score:2)
Reading the article it sounds interesting but the text seems vague. They describe it as cheap and easy to construct but I don't see anywhere if they built a prototype that produced a sustained X gallons/day over a time period like a month. A nice target would be the EPA estimate of 300 gal/day used by a typical US household.
No mention of any maintenance considerations or usable lifespan either.
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A (admittedly extremely wasteful generally) typical US household is most definitely not the target audience for this :D
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A (admittedly extremely wasteful generally) typical US household is most definitely not the target audience for this :D
That's ok, but pick a reasonable target and real-world test it. It's simple and cheap, so it should be easy.
Re: Have they built a prototype? (Score:2)
For example, a survival device for one person would be a great test - what would a 1 gallon/day device look like? What would it need electricity-wise?
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Reading the article it sounds interesting but the text seems vague.
Try reading the paper [nature.com], which is linked from TFS.
I don't see anywhere if they built a prototype that produced a sustained X gallons/day over a time period like a month.
Nope. This was just a test. I didn't see anything about durability either. Maybe that's in the supplemental material, which I believe is linked from the paper.
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Reading the article it sounds interesting but the text seems vague.
Try reading the paper [nature.com], which is linked from TFS.
I don't see anywhere if they built a prototype that produced a sustained X gallons/day over a time period like a month.
Nope. This was just a test. I didn't see anything about durability either. Maybe that's in the supplemental material, which I believe is linked from the paper.
I did read it, but it's pretty dense. There was one picture (really one quadrant in a picture) which kind of looked like a prototype but it wasn't very clear and the text didn't help. The thing is, as described it should be very easy to construct a prototype. The absorption material was described as very easy to make, and the rest of the device looks really simple too. So why not just build one instead of describing how one could be built?
And lemme guess (Score:2)
It works best in areas with high humidity because, well, in 0% humidity air there is little water to pull out of it.
In other words, it works where you don't need it. Great job. *golfclap*
every humid place has suplus drinkable water? (Score:2)
It works best in areas with high humidity because, well, in 0% humidity air there is little water to pull out of it.
In other words, it works where you don't need it. Great job. *golfclap*
Yup, EVERYONE in any place with greater than 0% humidity has ALL the clean, sanitary drinking water they ever need? They have all the industrial water they need? Plus maybe this makes an energy-efficient dehumidifier for industrial or possibly even home use.
So we should stop all basic research you don't understand the immediate practical benefit to?
You're shitting on scientists for building something you don't understand. I think we should fund basic research, even if there is no revolutionary app
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Well, yeah. If you look around you'll notice that the main problem with water is in area where humidity is generally low. Because if it was high, it would, ya know, rain eventually.
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It'll rain eventually. Like in Bangladesh, where it rains all at once and floods a sizable percentage of the country. But you might want to drink in between the monsoons, and Bangladesh had (has?) a serious problem with arsenic contamination in its wells. (Also which wells are arsenic-free changes. Good wells go bad. Bad wells recover.) Consistently safe potable water on the cheap would be nice in high-humidity places, too.
Re: And lemme guess (Score:2)
In other words, it works where you don't need it.
I've never been there to verify it firsthand, but I think the coastline around the Persian Gulf (particularly Dubai, Oman, etc) is an odd combination of 'hot desert' and 'brutal humidity'. Apparently, lots of water evaporates into the air from the Gulf making it unbearably humid, but very little falls as local rain. Ergo, "humid desert".
The tech might not be more useful in Dubai than, say, utility-scale reverse-osmosis... but might have potential as a way to improve the dehumidification of air conditioning.
Yeah but... (Score:3)
Pacific Crest Trail (Score:3, Interesting)
One of the issues with hiking the Pacific Crest Trail is the almost complete lack of water. Something like this could provide a reliable water source at shelters along the Pacific Crest and other national trail systems.
They said the same about the transistor (Score:2)
Or at best like so many of these "amazing world saving" technologies posted on /. they possibly sometimes work in a carefully controlled lab environment, but are not practical to scale commercially and we never hear about it again..
OK, so you either hate science or really don't understand it. They're reporting a scientific/engineering breakthrough. Part of basic research is there's a rather high percentage of discoveries that don't change the world. However, this may become revolutionary for the developing world or even basic infrastructures. We don't know. You really shouldn't shit on something just because YOU don't yet understand its impacts. It may be revolutionary, it may be a dud, but it takes some time to really know.
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Hey it works well enough for farmers on Tatooine to make a modest living - but then light sabers can block each other too so perhaps the laws of physics are different there.
Conjac Gum, $2/kg? (Score:2)
First, the components have to be cheap. Maybe they have some secret source, but a quick search on Amazon turns up much higher prices for the stuff.