question: Why is it that water vapor adds moisture to the air and prevents dryness, yet washing my hands/face with water makes them feel more dry?
comment: The water removes the oils from your skin, especially warm or hot water. It's the oils that make your skin more elastic and flexible
passages: Skin wettedness is defined as "the proportion of the total skin surface area of the body covered with sweat."
   Section::::Non-ideal rough solid surfaces.:Cassie–Baxter model.:"Petal effect" vs. "lotus effect".
   Section::::Ideal solid surfaces.:Minimization of energy, three phases.
  
  Figure 3 shows the line of contact where three phases meet. In equilibrium, the net force per unit length acting along the boundary line between the three phases must be zero. The components of net force in the direction along each of the interfaces are given by:
   Section::::Ideal solid surfaces.:Minimization of energy, three phases.:The Young–Dupré equation and spreading coefficient.
  
  The Young–Dupré equation (Thomas Young 1805; Anthanase Dupré and Paul Dupré 1869) dictates that neither γ nor γ can be larger than the sum of the other two surface energies. The consequence of this restriction is the prediction of complete wetting when γ  γ + γ and zero wetting when γ  γ + γ. The lack of a solution to the Young–Dupré equation is an indicator that there is no equilibrium configuration with a contact angle between 0 and 180° for those situations.
   Then one should rinse thoroughly, from the wrist to the fingertips to ensure that any microorganisms fall off the skin rather than onto skin.
  
  One should use a paper towel to turn off the water. Dry hands and arms with a clean towel, disposable or not, and use a paper towel to open the door.
  
  Moisturizing lotion is often recommended to keep the hands from drying out; Dry skin can lead to skin damage which can increase the risk for the transmission of infection.
  
  Section::::Techniques.:Low-cost options when water is scarce.
   Famously, there were two circumstances where one person said "water", but another person on screen got drenched. Both times, it was Christine McGlade who took the unfair waterings, and then got drenched again when she protested that she wasn't the one who said "water" (thus now saying it). The first of these was with Kevin Kubusheskie when he was wearing a suit of armor, and Ross explained that if he got hit, the suit would rust and since the studio had rented it, they would be liable for it, which they just could not afford. The other time was when Ross's nephew, Jeff Mosseau, was being protected from both water and slime due to Ross' fear that his mother would kill him. (Although Christine had to take his initial watering, he did eventually get slimed at the end of the show, much to Ross's horror.)
   In the most common case, a gas stream, e.g., air, applies the heat by convection and carries away the vapor as humidity. Other possibilities are vacuum drying, where heat is supplied by conduction or radiation (or microwaves), while the vapor thus produced is removed by the vacuum system. Another indirect technique is drum drying (used, for instance, for manufacturing potato flakes), where a heated surface is used to provide the energy, and aspirators draw the vapor outside the room. In contrast, the mechanical extraction of the solvent, e.g., water, by filtration or centrifugation, is not considered "drying" but rather "draining".
   The ladies wear jackets and petticoats of brown linen, with chip hats, in which they fix their handkerchiefs to wipe the sweat from their faces; but, truly, whether it is owing to the steam that surrounds them, or the heat of the water, or the nature of the dress, or to all these causes together, they look so flushed, and so frightful, that I always turn my eyes another way.
   Many techniques can be used to enhance wetting. Surface treatments, such as Corona treatment, plasma treatment and acid etching, can be used to increase the surface energy of the substrate. Additives can also be added to the liquid to decrease its surface energy. This technique is employed often in paint formulations to ensure that they will be evenly spread on a surface.
  
  Section::::The Kelvin equation.
   Section::::Effects unaccounted for.
  
  Section::::Effects unaccounted for.:The hydrophobic effect.
   A wetting agent is a surfactant that, when dissolved in water, lowers the advancing contact angle, aids in displacing an air phase at the surface, and replaces it with a liquid phase. Examples of application of wetting to pharmacy and medicine include the displacement of air from the surface of sulfur, charcoal, and other powders for the purpose of dispersing these drugs in liquid vehicles; the displacement of air from the matrix of cotton pads and bandages so that medicinal solutions can be absorbed for application to various body areas; the displacement of dirt and debris by the use of detergents in the washing of wounds; and the application of medicinal lotions and sprays to surface of skin and mucous membranes.
   Wet-on-wet painting has been practiced alongside other techniques since the invention of oil painting, and was used by several of the major Early Netherlandish painters in parts of their pictures, such as Jan van Eyck in the Arnolfini portrait, and Rogier van der Weyden. Among the many Baroque painters who favored an "alla prima" technique were Diego Velázquez and Frans Hals. In the Rococo era, connoisseurs appreciated bold "alla prima" painting, as exemplified in the works of artists such as Jean-Honoré Fragonard, Francesco Guardi, and Thomas Gainsborough.
   There are various factors affecting surface tension, one of which is that the "composition" of the surface may be different from the bulk. For example, if water is mixed with a tiny amount of surfactants (for example, hand soap), the bulk water may be 99% water molecules and 1% soap molecules, but the topmost surface of the water may be 50% water molecules and 50% soap molecules. In this case, the soap has a large and positive "surface excess". In other examples, the surface excess may be negative: For example, if water is mixed with an inorganic salt like sodium chloride, the surface of the water is on average "less" salty and more pure than the bulk average.
   Traditionally, a new layer of oil-based paint is applied to most parts of a painting only after allowing a previous layer to dry completely; this drying process can take from several days to several weeks, depending on the thickness of the paint. In contrast, work performed using "alla prima" can be carried out in one or more sessions (depending on the types of paint used and their respective drying times), and it is common for such a work to be finished in only one session or "sitting".
   BULLET::::- Drying with the jet-air dryer resulted in an increase on average of the total number of bacteria on the finger pads by 42% and on the palms by 15%.
  
  BULLET::::- After washing and drying hands with a paper towel, the total number of bacteria was reduced on average on the finger pads by up to 76% and on the palms by up to 77%.
   For example, if the vapor's partial pressure is 2% of atmospheric pressure and the air is cooled from 25 °C, starting at about 22 °C water will start to condense, defining the dew point, and creating fog or dew. The reverse process accounts for the fog burning off in the morning. If the humidity is increased at room temperature, for example, by running a hot shower or a bath, and the temperature stays about the same, the vapor soon reaches the pressure for phase change, and then condenses out as minute water droplets, commonly referred to as steam.
   Section::::DRY vs WET solutions.
   Section::::Contrast with spray drying.
  
  Spray drying is sometimes seen as a form of flash evaporation. However, although it is a form of liquid evaporation, it is quite different from flash evaporation.
   If we assume liquid water content (formula_10) is equal for the cloud before and after altering the particle density we obtain:
  
  formula_11
  
  Now we assume total particle density formula_6 is increased by a factor of 2 and we can solve for how formula_13 changes when formula_6 is doubled.
  
  formula_15= formula_16
  
  We can now take our equation that relates formula_3 to formula_10 to solve for the change in optical depth when the particle size is reduced.
  
  formula_19
   Based on this equation, the excess free energy is minimized when γ decreases, γ decreases, or γ increases. Surfactants are absorbed onto the liquid–vapor, solid–liquid, and solid–vapor interfaces, which modify the wetting behavior of hydrophobic materials to reduce the free energy. When surfactants are absorbed onto a hydrophobic surface, the polar head groups face into the solution with the tail pointing outward. In more hydrophobic surfaces, surfactants may form a bilayer on the solid, causing it to become more hydrophilic. The dynamic drop radius can be characterized as the drop begins to spread. Thus, the contact angle changes based on the following equation:
   Section::::Minimization of energy, three phases.:The Young–Dupré equation and spreading coefficient.
  
  The Young–Dupré equation (Thomas Young 1805, Lewis Dupré 1855) dictates that neither γ nor γ can be larger than the sum of the other two surface energies. The consequence of this restriction is the prediction of complete wetting when γ  γ + γ and zero wetting when γ  γ + γ. The lack of a solution to the Young–Dupré equation is an indicator that there is no equilibrium configuration with a contact angle between 0 and 180° for those situations.
   He was commissioned as a captain in the United States Air Force at the start of World War II and stationed in the Aleutian Islands as a war artist. The inclement, damp weather demanded that Pleissner work in watercolors because they dried faster than oil paints. But Pleissner recalled that even watercolors were difficult to use in the wet climate: “ I would go out to do these watercolors and it was so damn wet nothing would dry... I used to put out a few big washes and then run into and out of the huts where there was a fire and dry it and go out again.”
   The process of singeing is carried out for the purpose of removing the loose hairy fibers protruding from the surface of the cloth, thereby giving it a smooth, even and clean looking face. Singeing is an essential process for the goods or textile material which will be subjected to mercerizing, dyeing and printing to obtain best results from these processes.
   When someone said the word "water", "wash" or "wet", a large amount of ice cold water mysteriously cascaded onto them from above. This was also an homage to "Laugh-In", which featured their similar "Sock It To Me" sketches. In the early years of the show, cast members (especially Christine) were frequently nailed with pails of water physically thrown on them, but starting in 1981, this began to change to the much more mysterious motif of water falling down on the victim from above. By the 1984 season, only the word "water" led to a dousing or "watering"; where-as in earlier seasons, the words "wet" and "H2O also did. On occasion, cast members tried to "dodge" getting hit with water by saying ""agua"" (Spanish) or ""eau"" (French) instead, only to still be soaked anyway. (The latter was Christine actually saying "Oh, no you don't." but "oh" sounded too much like "eau".) One episode also had Christine McGlade and Kevin Kubusheskie drenched for saying "What're," the reason being that their speaking in "slang" sounded too similar to "Water."
   Consider again the example of water with a bit of soap. Since the water surface needs to have higher concentration of soap than the bulk, whenever the water's surface area is increased, it is necessary to remove soap molecules from the bulk and add them to the new surface. If the concentration of soap is increased a bit, the soap molecules are more readily available (they have higher chemical potential), so it is easier to pull them from the bulk in order to create the new surface. Since it is easier to create new surface, the surface tension is lowered. The general principle is:
  
presuppositions: If water normally adds moisture to the air and other objects, the same effect should apply to human skin. 
corrections: Water rids of the oil that lies in human skin which protects it and makes it more elastic and flexible.
raw_presuppositions: If water normally adds moisture to the air and other objects, the same effect should apply to human skin.  Water should make skin feel wet.
raw_corrections: Water rids of the oil that lies in human skin which protects it and makes it more elastic and flexible. Water strips skin of oils that protect it and make it elastic and flexible.