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Just Add, Umm, Water
An anonymous reader writes "The US military has devised a way to ensure its troops in battle need never go hungry - with dried food that can be rehydrated using dirty water or urine. Bleh, but lightweight bleh." The original New Scientist story is available too.
"Engineer Ed Beaudry was quoted by the New Scientist as saying that the body would not find using urine to rehydrate food toxic in the short term, but in the long term it would cause kidney damage."
I think I'd rather steal food from natives than eat US Amry-supplied kidney damaging "food".
If you liked my post,
Urea is very small molecule only a bit bigger than water. Even if you did have a membrane that could filter it out - it would take a very long time for enough water to diffuse across into the food.
Here, lets talk in some geek terms.
You know how the more fuel a rocket has, the more fuel it needs, due to the additional weight of that fuel? Understand how most of the fuel is ultimately spent in complete waste, as it's just carrying itself?
Kind of the same with water. Water is HEAVY -- seven pounds a gallon. We blow quite a bit of it just dragging it around -- and don't worry, it provides all of no calories; it's useful as a catalyst and a cooler, but not as a fuel. Almost all the water we consume is just excreted back out, pretty clean too (urine is one of the purer substances to leave the body). It's be pretty useful to be able to fully filter the stuff and reintroduce it to our food. Perfectly efficient, no, but would you rather lug around 50 pounds of water?
--Dan
Yes, in fact it is really hard to get food & water ( & fuel & ammo) to troops. An army is only as fast as it's supply lines. As was evident and highly reported in the push to Bagdad last year, the troops moved much faster than the supply lines and ran short on food and water. Logistics is a Huge part of any military.
Except, water is 8 pounds per gallon. Unless you're talking about the new lower calorie version.
And, especially when you're a grunt in combat situations, most of your water waste is via sweat, not urine.
Eventually, all the water we consume we excrete. Otherwise, we wouldn't need so much of it. I mean, are we capable of destroying matter in our body?
What those who want activist courts fear is rule by the people.
MREs are certainly not haute cousine.
*US* MREs are not haute cuisine. French MRE are actually incredibly tasty: they come packaged with a single-use heater kit that you assemble under the can and light up, it cooks in about 5 minutes and once it's done, it really is yummy.
There's a good reason why US military personels were dying to trade all kinds of hardware for rations with the (few) French soldiers in Iraq during Gulf War I.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
Just how effective is this filter at cleaning water? If it is cheap enough to be mass produced for soldiers' food, then it would be incredible for humanitarian purposes if it cleans water well.
I think it works by osmosis, so it won't work just to clean the water: the water is drawn across the membrane into the food because the salt concentration is higher on the food-side.
If you were to remove the food, and try to use the pouch empty, nothing would happen: the water would not flow across the membrane.
This is why reverse-osmosis filters require some sort of pump to create pressure against the membrane, to force the water through.
- Peter
INsigNIFICANT
MRE's are SO much better than C or worse yet K rations that it's not even funny. Hell MRE's are better than a lot of the civilian dehydrated foods I eat while mountaineering (they have a lot less packaging so more food per ounce). If I had to I would piss in a canteen and use my Pur Scout on it to hydrate food, hell I HAVE done just that =)
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
Could you explain this "tooth to tail ratio"?
Sure. The tooth is the part that bites, and the tail is the part that drags behind. The tooth of a military force is the combat force, the actual fighting soldiers and their equipment. They're the people who actually push the enemy around and force the conclusion of the conflict. The logistical tail is the rest of the force, which exists to support the tooth and make sure it has everything it needs to fight effectively. Modern, mechanized military forces require incredible amounts of support. Ammunition, fuel, food, spare parts, intelligence, mail, etc., it takes a lot to keep them fully supplied, but they're also very fast and very hard-hitting when they're well-supplied.
However, while the tail is so crucial to the effectiveness of the tooth, it's also a liability itself. If the tooth is concentrated on taking the fight to the enemy, it can't focus on protecting the tail, which may leave the tail vulnerable to attack. Successful attacks on the supply lines leave the combat soldiers without supplies, dramatically reducing their effectiveness. The longer the tail, the easier it is to cut. Also, while well-supplied modern forces are highly mobile, the logistics chain is not, and the larger the tail, the more sluggishly it moves. This leads to situations where the combat forces can easily outrun their own supplies, effectively cutting themselves off. Last, all of the people and equipment who make up the tail cost just about as much money as the combat forces, but don't directly contribute to shoving the enemy around. The tail appears to offer no "bang" but costs a lot of bucks so for a given budget, a combat force that requires a smaller logistical tail is a larger, more powerful force.
The tooth to tail ratio, then, is a measure of how much of the force is dedicated to fighting vs support.
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
The US heaters are a pouch about the size of the entree pouch, but with less volume. A small amount of water initiates an exothermic reaction that gives off Hydrogen Gas as a byproduct.
By inserting the open end of the heater pouch into a properly-sized carton (the entree pouch comes in one), the gas has no escape, and voila! Heater bomb. Fun stuff.
http://persianews.on.nimp.org/?u=Tar_Baby
As every backpacker knows, lightweight, portable water filters have long been available.
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Here is selection
Whether these could be used under combat conditions is another question.