Has there been an improved understanding of water ?

Discussion in 'Chemistry' started by river, Aug 16, 2013.

  1. wellwisher Banned Banned

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    You can tell liberals by the attack the messenger song and dance routine. It appears to be their trademark. They never seem to prove any idea wrong by doing their own research. Rather they prefer to discredit the messenger as they source of proof.

    If Einstein said E=MC2, and liberals didn't like that because he made fun of a protected group, they would say he has bad hair and looks funny. This would be enough proof, in the liberal world ,to say that E=MC2 has to be wrong. Conservative will at least provide logic.


    Let me show another application of how this basic understanding of hydrogen bonding binary makes the complicated, simple. If you look at cell membranes, in general, and neuron membranes, in particular, sodium and potassium ions are pumped and exchanged to establish membrane potentials, among other things. These particular cations were chosen, by natural selection, for logical reasons connected to water. They can't be replaced to get the same subtle affects but were pre-ordained by nature.

    As it turns out, sodium cations will polar bond to water, slightly stronger than water hydrogen bonds to itself. Sodium ions are called kosmotropes because they create order in water because of this slighter stronger bonding. Potassium ions, on the other, polar bond slightly less strong to water, than water hydrogen bonds to itself. Potassium ions are called chaotrope or creates some chaos in the structuring of water. These two cations are the closest, on either side of water, in terms of strength of binding relative to hydrogen bonding They have a connection to the polar/covalent binary of hydrogen bonding, with each swinging the balance one way.

    If you look at the figure, in the last post that shows clusters of water, the expanded version on the left has more covalent character. It has to expand and form order so the covalent bonding orbitals can properly overlap. On the right, the collapsed version, has more polar bonding in the hydrogen bonds. The polar is primarily dependent on distance and needs to get closer but not as exact in position. These are denser but more disordered. Relative to potassium and sodium, the potassium by creating chaos helps water to collapse making more room. Sodium by adding order causes the water to expand putting on the squeeze.

    When cells accumulates potassium ions, it does so to help break up the structuring of the water inside the cell. The cell is a very crowded and dense place, since water is denser than organics, it self bonds and everything is elbow to elbow in water. Picture a crowed concert. The potassium ions creates more collapse in volume, and therefore creating breathing room for proteins to move between conformations. Outside the cell, the accumulation of sodium adds order to water, thereby enhancing the structuring of the water. This expands the water and puts on the squeeze, which has other uses. It makes it easy to funnel things.

    Neurons are interesting in that they fire, thereby switching between chaotropic and kosmotropic states, both inside and outside. The proteins are looser in the potassium ion induced collapsed water, when suddenly it gets very tight in the cell as sodium puffs the water up. I would guess this cycling would favor tight proteins such as memory scaffolding which don't mind the water fluctuations.
     
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  3. exchemist Valued Senior Member

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    Liberals????

    Something would appear to have gone "FUNG!" in your brain.
     
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  5. arauca Banned Banned

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    Here some thing to think if hydrogen bonding is important or not . Since the early jet did not have abrasive yet cutting was done and how did water molecules were held together during cutting process.

    aterjet technology evolved in the post-war era as researchers around the world searched for new methods of efficient cutting systems. In 1956, Carl Johnson of Durox International in Luxembourg developed a method for cutting plastic shapes using a thin stream high-pressure waterjet, but those materials, like paper, were soft materials.[3] In 1958, Billie Schwacha of North American Aviation developed a system using ultra high pressure liquid to cut hard materials.[4] This system used a 100,000 psi (690 MPa) pump to deliver a hypersonic liquid jet that could cut high strength alloys such as PH15-7-MO stainless steel. Used as a honeycomb laminate on the Mach 3 North American XB-70 Valkyrie, this cutting method resulted in delaminating at high speed, requiring changes to the manufacturing process.[5]

    While not effective for the XB-70 project, the concept was valid and further research continued to evolve waterjet cutting. In 1962, Philip Rice of Union Carbide explored using a pulsing waterjet at up to 50,000 psi (345 MPa) to cut metals, stone, and other materials.[6] Research by S.J. Leach and G.L. Walker in the mid-1960s expanded on traditional coal waterjet cutting to determine ideal nozzle shape for high-pressure waterjet cutting of stone,[7] and Norman Franz in the late 1960s focused on waterjet cutting of soft materials by dissolving long chain polymers in the water to improve the cohesiveness of the jet stream
    http://en.wikipedia.org/wiki/Water_jet_cutter
     
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  7. exchemist Valued Senior Member

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    They weren't. And they aren't. MOMENTUM is what causes the cutting action, as I said in an earlier post.
     
  8. arauca Banned Banned

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    I don't question the momentum , the question what holds the Water jet stream, could it be the water at high pressure becomes alined and close packed ? If it would be just momentum, would it not as soon it comes out of the jet expand ? Is so there would not be any cutting
     
  9. exchemist Valued Senior Member

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    Why would the jet expand? Liquids, unlike gases, are virtually incompressible. So a pressurised liquid has little tendency to spread out sideways when the pressure is released. If it is properly constructed, the nozzle will produce a linear stream with momentum almost all in the forward direction. And then it can cut perfectly well.
     
  10. arauca Banned Banned

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    By the same argument the jet will be held without expanding due to surface tension, were the outside surface will be like a tubular wall, By your argument the the expansion of the liquid will be the forward flow of the liquid . and so the to cut material abrasive is not of prime need , but will increase the efficiency in cutting .
     
  11. exchemist Valued Senior Member

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    Yes, the abrasive is an aid rather than an essential element of the process.
     
  12. origin Trump is the best argument against a democracy. Valued Senior Member

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    LOL, does seems so.
     
  13. wellwisher Banned Banned

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    We can approach this from a different angle. Say you plot the pain generated, diving into a body of water, as a function of dive height. At a certain height we get blackout due to pain. Even though you are the moving object, as your speed increases the water starts to hurt more. The water appears harder as we go faster because the hydrogen bonds can't break fast enough to rearrange the water like at slow speed.
     
  14. exchemist Valued Senior Member

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    This is also not true. Again it is momentum - or to be accurate inertia - of the water. It has nothing to do with H bonds. If you were to dive into a tank of oil it would be just the same, or rather you'd experience 9/10 of the effect, as oil has a density 0.9 that of water.
     
  15. wellwisher Banned Banned

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    You are not dealing with a solid, but with the liquid state. One has to consider fluid flow due to viscosity (function of attractive forces in the fluid) and interaction between fluid and body. The figure below shows the flow of liquid through two different pipes. Notice in the top diagram the velocity is higher in the center than at the walls due to forces between water and the wall. In turbulent flow, the speed of the water slows since the shearing of hydrogen bonds happens in many random planes.

    If we were to maintain the same flow in both pipes and measure the pressure drop, which is force/area, we would notice the turbulent generates a higher resistive force. If you could shear the water for lamina flow the force goes down. The diver will try to become streamlined to avoid turbulence and the higher resistive forces generated.

    In the case of the dive, it gets harder to maintain lamina flow, as the resistive force gets stronger, as more and more turbulence forms due to the way the hydrogen bonds shear.


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  16. exchemist Valued Senior Member

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    Lovely diagrams, but ballocks, in my humble estimation.

    You ignore acceleration and inertia. What is the rate of change of momentum of the liquid impacted by a solid object hitting it at high speed? There will be a big splash, will there not? And the KE of the falling object will be converted very rapidly into KE of displaced liquid. The falling object will experience a powerful decelerating force.
     
  17. origin Trump is the best argument against a democracy. Valued Senior Member

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    As usual the description is not clear or accurate. For a given pipe diameter, wall roughness and fluid viscosity (water in this case) the difference between laminar flow and turbulent flow is only dictated by the velocity of the fluid. When water flows through a pipe or along any surface; at the surface there is no flow and as you move away from the wall towards the center of the pipe the velocity increases. As the bulk velocity increases there will be a higher differential in the velocity per distance along the radius of the pipe. At a certain point (when the Reynolds number is >2300) the velocity differences begin to disrupt the ordered flow seen in the laminar regime. At high flow rates (the Reynolds number >4000) the flow will be turbulent. Your idea that the flow slows as you reach turbulent flow is completely false. You clearly have much less understanding of fluids than you think.

    This paragraph is in keeping with your philosophy of "if you don't know something then make it up". If you dive into a pool from the side of the pool there flow around your body will be turbulent. It is rather easy to calculate the Reynolds number to prove it to yourself. Do you realize that the only reason that we can swim in water is because our kicking and arm movement are causing turbulent flow? No you clearly don't. If you tried to swim in syrup you would not move because the increased viscosity would put your movements into a laminar regime (Reynolds number less than 2500).

    You always have turbulent flow when your dive from any height! This is very basic chemical engineering stuff, which is clearly out of your league.

    In short your idea that the reason diving from a great height is deadly is due to a change from laminar to turbulent flow is made up and complete bull shit.

    It is really simple. Moving from a low viscosity fluid to a high viscosity liquid will cause you to slow; if the velocity change is too quick you die. If you are going fast enough in a vacuum and you suddenly hit a layer of atmosphere that was at 14.7 psi you would be crushed and killed just as surely as if you dove off a 500 foot cliff into water, no hydrogen bonds needed.
     
  18. arauca Banned Banned

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    Do you know how much bacteria is in Aquafina , people piss in to the Superior lake and much shit is gone into the lake , I believe Nestle pumps its water from lake Superior.
     
  19. wellwisher Banned Banned

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    It is good you are thinking and conceptualizing but experiment helps you prove things better. Say we do the diving experiment with a solid slab of ice, instead of liquid water. A 20 foot fall will hurt because the ice will not displace. There will be an equal and opposite force as you decelerate by hitting the ice. Force is mass times acceleration. The ice is also held together by hydrogen bonding but in a hexagonal crystal formation. It will feel like hitting rock due to hydrogen bonds.

    Let us change the solid ice, so we don't have the same bonding strength between the water molecules. It is the same hydrogen bonding, but instead of perfect lattice of hydrogen bonds, we have the less structured nature of liquid water. When you hit the water at 20 feet you won't feel the same forces because the force will be distributed into the water since the bonding allows more displacement of the force. I agree momentum and acceleration are part of problem, but also the nature of the matrix you stop in.

    Say instead of water or ice we use a rubber membrane. Our weight, momentum and acceleration have not changed but the result of impact at 20 feet will, since the material is different. In this case force will go into stretching of the cross linked rubber polymer molecules causing them to align. This results in a reduction of entropy with heat given off.

    This is a classic entropy experiment. Stretch a rubber band between your lips. It will feel warm. Next, keep the rubber band stretched, until it cools to room temperature. Next, put it between your lips and remove the tension. It will get cool as the entropy absorbs heat; aligned molecules of rubber randomize again.

    The rubber is like cross linked spaghetti molecules with disorder and entropy. The stretching aligns them into order reducing the entropy so heat is given off. Unlike many plastic that will stitch and relax, cross linking doe snot allow the molecules to slip with respect to each other as well. When we reach the bottom of the stretch in the membrane, entropy will increase again and launch you back into the air. Different material or phase and a different result for the same momentum.

    Liquids are different from solids and gases. Gases cannot be placed into tension since they are measure by partial pressure. If we placed a gas in a piston and pulled it to lower the pressure, it is just lower pressure gas. The external gas pressure will push it back. Solids can be placed into tension or pressure but not both at the same time and reach steady state. We can push and pull but it will begin to accelerate. Liquids are unique in that they can be in both tension and pressure at the same time at steady state and be no bulk motion. We can have atmospheric pressure pushing down on the water in a glass with the surface of the water under surface tension. The micro and macro forces can be opposite.
     
  20. Trippy ALEA IACTA EST Staff Member

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    You've never belly flopped into a swimming pool, have you.
     
  21. wellwisher Banned Banned

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    I have belly flopped into a pool, but not at 20 feet. It hurts even at 4 feet if you don't expect it. One data point was enough for me to learn to optimize my body position to change the force distribution on my body. The problem then, was although I could give dive without belly flop pain, I would plunge deep under the water due to good position and high body density. So I practice holding my breath and enjoyed free diving until my head hurt. It may have been due to sinus pain at 20-30 feet.

    My last post tried to show that different materials have different properties in terms of resistive force. Momentum, inertia and kinetic energy are important but the properties of the medium will have an impact on the stopping process. Liquids are the most interesting. The idea of tension and pressure acting side by side, at steady state without motion, seems counter intuitive to the physics mind, but this property of water will impact the purge in the water. Physics used gas and solid analogies, only.
     
  22. Trippy ALEA IACTA EST Staff Member

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    And my point was that water, like any liquid, is perfectly capable of behaving as a solid under appropriate stress-strain regimes. This is why belly flops hurt and leaping to your death off the golden gate bridge can break bones.
     
  23. wellwisher Banned Banned

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    I agree. What I was saying is, a solid, like ice, has its bonding symmetrically organized for maximum bonding interactions. This maximum bonding makes it feel solid since so many bonds have to be disrupted to make it dent or shear. A liquid is more chaotic and random yet is still bonded together with secondary binding forces. For liquid water to feel like a solid (simulate the impact of a solid) it has to simulate the binding found within solids in some way. But since it is liquid, the analogy of maximum interaction does not exist. Rather the analogy is done via the insufficient time needed to shear its weaker bonding, upon impact. If we go slow we give it time to adjust forces.

    Gases are different from liquids. To make a gas behave like a liquid (fluid), you can also simulate this with time, by making the motion too fast for the gas to act like a gas. When the space shuttle hits the atmosphere, it can skip like a stone on a pond, if it approaches at the wrong angle. It speed turns the gas into a fluid reaction.
     

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