Search results
Results from the WOW.Com Content Network
Diffusion is a property of substances in water; substances in water tend to move from an area of high concentration to an area of low concentration. [26] Blood flows by one side of a semi-permeable membrane, and a dialysate, or special dialysis fluid, flows by the opposite side.
Self diffusion, exemplified with an isotopic tracer of radioactive isotope 22 Na Example of chemical (classical, Fick's, or Fickian) diffusion of sodium chloride in water. Fundamentally, two types of diffusion are distinguished: Tracer diffusion and Self-diffusion, which is a spontaneous mixing of molecules taking place in the absence of ...
The higher the diffusivity (of one substance with respect to another), the faster they diffuse into each other. Typically, a compound's diffusion coefficient is ~10,000× as great in air as in water. Carbon dioxide in air has a diffusion coefficient of 16 mm 2 /s, and in water its diffusion coefficient is 0.0016 mm 2 /s. [1] [2]
Fick's first law relates the diffusive flux to the gradient of the concentration. It postulates that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative), or in simplistic terms the concept that a solute will move from a region of high concentration to a region of low ...
Such a rapid rate is characteristic of a diffusion-controlled reaction, in which the rate is limited by the speed of molecular diffusion. [ 15 ] Relationship with the neutral point of water
The diffusion coefficient can be combined with the reaction ... ASTM F1249 Standard Test Method for Water Vapor Transmission Rate Through Plastic Film and Sheeting ...
In engineering, the mass transfer coefficient is a diffusion rate constant that relates the mass transfer rate, mass transfer area, and concentration change as driving force: [1] = ˙ Where: is the mass transfer coefficient [mol/(s·m 2)/(mol/m 3)], or m/s
Multicomponent diffusion is diffusion in mixtures, and diffusiophoresis is the special case where we are interested in the movement of one species that is usually a colloidal particle, in a gradient of a much smaller species, such as dissolved salt such as sodium chloride in water. or a miscible liquid, such as ethanol in water.