Page 325 - Advances in Biomechanics and Tissue Regeneration
P. 325

16.5 IMPLEMENTATION                                    323

           16.5.1.2.1 CELL POPULATIONS
              Plugging Eq. (16.36) into Eq. (16.29), we obtain
                                     N                   !
                               Z          r      Z              Z        Z
                                    X  ∂C                                     ∂C i
                                   ϕ      i  ϕ dΩ   —ϕ   A i dΩ ¼  ϕa i dΩ   ϕ   dΓ, i ¼ 1,…,n             (16.37)
                                            r
                                Ω    r¼1  ∂t      Ω              Ω        Γ R i  ∂n
           Using linear properties of — operator, Eqs. (16.13), (16.15), (16.17), (16.20), (16.22) may be written as
                                                     N
                                                    X    r
                                             q         ðC K D,i Þ—ϕ , i ¼ 1,…,n
                                              D,i  ¼     i       r
                                                     r¼1
                                                      0          1
                                                    N    k
                                                   X X     r
                                             q        @   p K m,i, j —ϕ , i ¼ 1,…,n
                                              m,i  ¼       j         r
                                                                 A
                                                   r¼1  j¼1
                                                      0         1
                                                    N    n
                                                   X X     r
                                             q        @   S K s,i, j —ϕ , i ¼ 1,…,n
                                              s,i  ¼       j         r
                                                                A
                                                   r¼1  j¼1
                                                    N
                                                   X    r
                                             q E,i  ¼  ðθ K E,i Þ—ϕ , i ¼ 1,…,n
                                                               r
                                                   r¼1
                                                    N
                                                   X    r                                                  (16.38)
                                             q        ðV K T,i Þ—ϕ , i ¼ 1,…,n
                                              T,i  ¼           r
                                                   r¼1
           So, as A i ¼ C i v+q i it is obtained
                                   N     !
                                  X    r
                                     C ϕ   v
                            A i ¼      i  r
                                   r¼1
                                     0                                           1
                                   N             k         m
                                  X      r      X  r       X  r       r      r
                                +    @  C K D,i +  p K m,i, j +  S K s,i, j + θ K E,i + V K T,i —ϕ , i ¼ 1,…,n  (16.39)
                                                                                      r
                                         i
                                                   j
                                                              j
                                                                                 A
                                  r¼1           j¼1        j¼1
           And —ϕ  A i writes
                                      N
                                     X
                                         r
                                              i
                                                                r
                                                       i
                                         i
                                                r
                            —ϕ   A i ¼  C ð—ϕ   ϕ v —ϕ  ðK D,i —ϕ ÞÞ
                                      r¼1
                                             0                                   1
                                       N        k          m
                                                              r
                                                   r
                                                                             r
                                      X        X          X
                                                                      r
                                     +   —ϕ    @  p K m,i, j +  S K s,i, j + V K i,E + θ K i,T —ϕ , i ¼ 1,…,n  (16.40)
                                                                                 A
                                                   j
                                                              j
                                                                                     r
                                       r¼1     j¼1        j¼1
                       r
           Besides, as C ¼ C ðtÞ, ϕ ∂C r i  writes
                           r
                       i   i     ∂t
                                                 N    r      N
                                                               _
                                                 X  ∂C      X   r
                                               ϕ      i  ϕ ¼ ϕ  C ϕ , i ¼ 1,…,n                            (16.41)
                                                        r
                                                                  r
                                                    ∂t          i
                                                 r¼1        r¼1
           Choosing ϕ ¼ ϕ s , s ¼ 1, …, N (Galerkin method) and reorganizing terms in Eq. (16.40), we may write
                                                  N        m  N
                                                 X  ^  ðiÞ  r  XX ^  ðijÞ  r  ^ ðiÞ
                                                     C +          S + F , i ¼ 1,…,n
                                           s                                                               (16.42)
                                        —ϕ   A i ¼   sr  i        sr  j  s
                                                 r¼1       j¼1 r¼1
           with
                                ^
                                  ðiÞ  ¼ð—ϕ  ðϕ vÞ —ϕ  ðK D,i —ϕ ÞÞ, i ¼ 1,…,n
                                                              r
                                              r
                                  sr
                                          s
                                                     s
                                    ¼ —ϕ   K s,i, j —ϕ , i ¼ 1,…,n
                                ^ ðijÞ
                                                  r
                                         s
                                           2   0 0     1                    1    3
                                             N      k
                                ^  ðiÞ      X      X  p  r A K m,i, j + V K E,i + θ K T,i —ϕ , i ¼ 1,…,n   (16.43)
                                                                        r
                                                                 r
                                F
                                         s
                                  s  ¼ —ϕ    4  @ @    j                    A   r  5
                                             r¼1   j¼1
                                          II. MECHANOBIOLOGY AND TISSUE REGENERATION
   320   321   322   323   324   325   326   327   328   329   330