HW6 ENME382 S10 Section0201 solution

HW6 ENME382 S10 - ENME 382 Homework 6 1a How can you distinguish between steady state and non-steady state diffusion In steady-state diffusion the

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
ENME 382 Homework 6 1a) How can you distinguish between steady state and non-steady state diffusion? In steady-state diffusion the diffusion flux and thus the concentration profile are independent of time. There is no net accumulation or depletion of the diffusing species. In non-steady state diffusion, the concentration profile changes with time. This is usually a result of a finite source of the diffusing species becoming depleted or the lack of removal of reacts in a reaction that occurs as a result of diffusion. b) What is the driving force for steady state diffusion? The most common driving force for steady state diffusion is a concentration gradient. As noted in class the most general answer to this question is that the driving force is a chemical potential gradient, this includes temperature gradients, electric field gradients, stress gradients, etc. c) When would you expect a vacancy diffusion mechanism? Vacancy diffusion means the interchange of an atom from a normal lattice position to an adjacent vacant lattice site or vacancy. Therefore, it can occur when there are vacancies existing in the lattice
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/28/2010 for the course ENME 250 taught by Professor Shang during the Spring '10 term at Maryland.

Page1 / 3

HW6 ENME382 S10 - ENME 382 Homework 6 1a How can you distinguish between steady state and non-steady state diffusion In steady-state diffusion the

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online