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TL;DR: Its not the air that's enclosed inside that creates the force, but the lack of air - or more precisely pressure. First of all some nomenclature (this is for the closed type, there is also the open type): When you press a suction cup on a surface what happens is that the air inside it is pushed out. During the compression phase of the cup the air ...


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When you push that onto a flat surface it pushes most of the air out. The elasticity of the item makes want to flex and come off but the air pressure is pushing it onto the surface.


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Compressing air (for energy storage or other purposes) heats it up, expansion cools. For energy storage the heat has to be stored, a detailed description can be found here. Cooling air further would require additional energy input - twice, for cooling and then again for reheating upon expansion. Again, see the link for details. Compression concentrates dust ...


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In the world of heating/ventilating/air conditioning engineering (a.k.a. "HVAC") there is a number called the comfort index (which you can search on) which takes both humidity and temperature into account to determine where most humans would feel comfortable. This will tell you the range of optimum humidity percentages to shoot for at a given temperature ...


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I would recommend a modification Phil's answer: airflow is almost always better when the fan is exhausting to the outside - fans don't "like" back pressure and work most efficiently when dumping to an open area. So, use a fan in the window to push air out, and fill the rest of the window with an inlet duct which is routed up to your loft. This way, there'...


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Air hates to flow into corners, even if there is a fan. A thermally stratified box is about the most obstinate thing there is to make comfortable. The best solution would be to run a small duct against the wall from the floor up through the sleeping loft floor near your feet and on up another 40cm. Something like 5cm x 20cm. Use a fan to push air up the duct....


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Fit a dummy test hose with no leaks - a solid tube for example, then pressurise the system to a known value perhaps the maximum used +10%. Then take readings every 10 seconds / 5 minutes (whatever is relevant for your real tests) for a defined amount of time ie 10* the length of a normal test. Repeat 10 times. Average the results for the "loss per unit ...


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If you are opposed to 3D printing due to the requirement for mass production, then you may be able to work with an injection molding company to design a product that at least has the curved channels done. Post molding, you can go back out and drill out the straight runs as needed. If you need to connect two channels, you can cross drill and plug the holes. ...


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They don't prevent condensation. They just reduce the chances of condensation getting onto your kit down to practically nothing, if you do it right. The condensation stays on the inside of the outer layer. Your kit is on the inside of the inner layer. The condensation doesn't cross the gap between the inner and outer layer. It runs down the inside of the ...


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each "end" of the airlock has a valve in it which, when opened, allows the pressure between the inside of the airlock chamber and the pressure inside the adjacent chamber to equalize. Once this is done, the equalizing valve is shut and then the door to the adjacent chamber can safely be opened.


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Figure 1. A typical aerosol valve. Source: Wikimedia. An Internet image search will show that most aerosol valves are of the type shown in Figure 1. Here it should be clear that if the differential pressure across the valve is reversed (pressure inside < pressure outside) that the valve will tend to open. The internal spring opposes the opening and so ...


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The valve on such a can may be engineered to resist internal pressure in such a way as to seal when the can's contents are in place. If the can is completely empty and placed in a vacuum chamber, it's possible that you can evacuate any additional gases within, but once the vacuum is removed, the can will "suck" in air until at near-ambient pressure.


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Let us presume that the process being considered is vaporization of liquid water to a gas state in dry air. As long as the temperature and pressure of the liquid water is constant during the process, vaporization of the liquid to gas in dry air will not change the molar enthalpy of the remaining liquid. In those cases where for example the temperature of the ...


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For a less messy way to determine the volume of shaving cream use a three dimension scanner and software that can determine the volume of scanned items. Acquire some stainless steel, plastic or ceramic tiles. Weigh a tile. Place a dollop of cream on the tile. Weigh the tile with the cream & subtract the mass of the tile. Place the tile with cream in a ...


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So two possibilities: One, pre filter the air prior to cooling/freezing Two, will the impurities freeze and soldify first? If so remove solids before final freezing. Are you freezing the air to a solid / liquid as this may make a difference.


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The fundamental problem is: how do you reject the optical signal from solids or liquids "behind" the air mass you want to measure? The esoteric methods reported in : https://pdfs.semanticscholar.org/9ccd/6df082576a620a2a89f8e6b7203186e6b08c.pdf , http://www.mdpi.com/1424-8220/18/1/72/pdf may work, because they indirectly measure air temperature rather ...


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I can think of two reasons why this might happen, though I don't know for sure. First, air trapped in the test piece could be slowly dissolving into the water, which will change the overall density and hence the pressure. This doesn't happen when pure nitrogen is used because the nitrogen is not dissolving into anything. Second, the mechanical parts of ...


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Lost Foam Casting Can produce many smaller structures Can be scaled up for reasonable costs Relatively cheap (compared to many other castings types and 3D printing). Can produce items with channels, which would normally require cores to be inserted. Foam is very easy to form and shape


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From a simple physics perspective, please consider the following. A fan or blower located in or near the window will pull cooler air into the room. Ideally, you have to have a means to exhaust the ambient air, allowing such airflow. This would require an exhaust portion in the window partially separated from the fan. As you've noted, hot air is in the upper ...


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In general, for air life-time, no tubing manutcurer will recommend a useful lifetime beyond 20 years, no matter the service. This isn't really due to shoddy craftmanship, but due to creep and test data. All plastics experience creep - a phenomenon where the material will continue to deform so long as it is being stressed. No matter how low the pressure of ...


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