Still water droplet evaporation rate (help using Maxwell's formula please)

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SUMMARY

The discussion centers on the evaporation rate of water droplets using Maxwell's formula, specifically the equation I = 4 Pi D R (c1-c2). The user is studying anhydrobiosis in organisms and seeks to understand the dissociation coefficient (D) and its dependence on various factors such as temperature and solute concentration. They express difficulty in navigating advanced calculus and existing literature, particularly regarding the application of Maxwell's formula in meteorology and evaporation studies. The conversation highlights the importance of correctly interpreting units and variables to avoid errors in research publication.

PREREQUISITES
  • Understanding of Maxwell's formula and its applications in evaporation
  • Basic knowledge of calculus for interpreting equations
  • Familiarity with concepts of anhydrobiosis and trehalose as a protective agent
  • Knowledge of gas laws and their relation to evaporation rates
NEXT STEPS
  • Study the derivation and application of Maxwell's formula in evaporation contexts
  • Learn about the dissociation coefficient (D) and its temperature dependence
  • Research Seaver's equation for droplets smaller than 2 microns and its implications
  • Explore Fuchs' work on gas laws and unit conservation in evaporation calculations
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Researchers in biology, physics, and environmental science, particularly those studying evaporation processes, anhydrobiosis, and the mathematical modeling of droplet behavior.

zoofog
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So I've observed the animal I am studying dry it's self (a survival mechanism called anhydrobiosis) to avoid freezing (laseration by ice crystals). Life forms given time produce a number of protectants in order to survive. Trehalose a sugar is produced to 2-4%. This will act as an antifreeze to aprox minus 4 C. Additionally Trehalose appears to act as a water substitute protecting structures from failing due to dehydration. Protein molecules deprived of water will fold into new incompatible structures collapsing the house of cards that is life. I am trying to write a paper for publication and I want to master this equation ( I = 4 Pi D R (c1-c2)). I have spent day's trying but still do not have a clear idea. Examples I have found use it as a reference point and mostly a starting point to add variables ( velocity and heat flows ) formulated with advanced calculus most of all fail because the added variables are unstable in nature and then the next researcher starts again with Maxwell. You get a sense of the genius of Maxwell by leaving the obvious ( velocity and heat) out. I am not a genius and am unable to read around the advanced calculus content of these journal articles. I just want a sense of the maximum evap rate as a percent of drop mass. One could also call it initial evap rate. My drops (the organism) temperature, diameter and concentration of solutes will immediately change with the evaporation. My biggest problem with the formula has to be with the dissociation coefficient. I have read "the quantity of gas traveling one cm through one cm x cm. Then I'll see 1 m x 1m so in that case is the travel distance a meter or still one cm through orifice of area x. Not mentioned is the units of the quantity ( example grams, moles etc ). I saw something like D = 0.022 + (0.134 c1-c2). Density effects D. D for water is different than for methane etc. I think it's different for different temperatures. I want to carefully get the correct D, conserve my units so the final answer makes sense and is correct. I don't want to be forced to print a retraction. Most of the work that I could find using this rarer Maxwell formula is for metereology and some evaporator uses, spray use or to explain other phenomonom like sailors being pelted with dry salt crystals while at sea.
 
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I googled this topic: See https://www.tandfonline.com/doi/pdf/10.1080/02786828408959006
Equation (3) is a better form of Maxwell's formula. The effusion rate (number per second per unit area) ## R=\frac{n \bar{v}}{4} ## is a well-known result that can be derived with some calculus.(##n ## is the concentration=number of particles per unit volume). I don't know that you have your units right in the OP, but again see equation (3). The ## 4 \pi R^2 ## in that formula is the surface area of the droplet. (3) makes complete sense.:welcome:
 
Charles Link said:
I googled this topic: See https://www.tandfonline.com/doi/pdf/10.1080/02786828408959006
Equation (3) is a better form of Maxwell's formula. The effusion rate (number per second per unit area) ## R=\frac{n \bar{v}}{4} ## is a well-known result that can be derived with some calculus.(##n ## is the concentration=number of particles per unit volume). I don't know that you have your units right in the OP, but again see equation (3). The ## 4 \pi R^2 ## in that formula is the surface area of the droplet. (3) makes complete sense.:welcome:
Thank you ever so much. It will take me time (as probably days) to digest and use the new search terms to learn what I can on my own before asking for more help. Thanks again. I was mistified why circumference and not surface area was in my equation.
 
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I looked at the Seaver (1983). I wish I could understand it fully (or even partially). I forgot calculus it came easily and went just as easily (40 years ago). Seaver though is developing a formula for drops smaller than 2 microns and Seaver confirms any drop larger is Maxwellian (ie yields best correlation to experimental data). Taking your lead of Seaver's equation (3) I am reading Fuchs (1959) rendition that in part is available on Google books and I'll see where it takes me. Fuch's is good about symbols and in conserving units and actually provides a Maxwell gas law combo equation that will let me input my partial pressures without the risk of deriving the wrong equation on my own. Algebra I am still sound on and Fuchs first chapter is Algebraic.
 
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