Page 137 - ITU Journal Future and evolving technologies Volume 2 (2021), Issue 3 – Internet of Bio-Nano Things for health applications
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ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 3




          Mathematically  speaking,  one  can  integrate  the                  2           −         2
          volume in both sides of Eq. 18 , so that one gets:                   ∫      (  )        =    ∫   .         
                                                                                                
                                 2                                              −    (  )       2           (    )
               ∫  (  ,   )     =    2  ∫   (  ,   )       +     ∫   (  ,   )       =
                                  2                                                    
                                                               Where Gauss’s law was employed but in the form of:
                        − (   −     ) ∫   (  ,   )          (    )
                                
                                                                                          (  )
          From  the  side  of  electricity,    (  ,   )  denotes  the         ∫  .           =              (    )
          volumetric charge density transported by bacteria,   With  “  ”  a  permissivity  constant  different  to "  ”
          fact that implies that its integration over the volume   because equipotential lines might not be inside the
          containing the charge turns out to be the net charge:   region  of  electric  field  in some points  of space  of
            (  ) = ∫        (  ,   ). Under this view the left side of   bacteria displacement, so that only a single medium
          Eq. 19  is recognized as the  instantaneous  electric   is not expected. Instead up two media or more can
          current. Thus, one arrives at:                       coexist together. A similar procedure can be applied

                  (  )      2     2                            to the second term of the right side of Eq. 21:
                    =   (  ) =     ∫   (  ,   )       +     ∫   (  ,   )     
                                  2                                                               (  )
                                 2                                        ∫   (  ,   )      =   ∫      (  )          (    )
                        − (1 −  2 ) ∫  (  ,   )         (    )                                          
                                
                                                               and again, one can construct the electric potential
          By  assuming  the  cylindrical  coordinates  system   yielding  finally that  the  term  of Eq.  27  is  linearly
          then the variable “x” is now changed to be the radial   proportional to the cylindric radius:
          coordinate. Then one gets:
                                                                                         (  )
                                                                                  ∫      (  )         =
                   (  ) =    2  ∫   (  ,   )       +     ∫   (  ,   )                          
                                             
                                                                                 −              −    (  )        
                        − (   −  )   (  ).            (    )         ∫      (  )      =  ∫         =      .  (    )
                                                                                                        
          Now special attention is paid on the first term of the   It should be noted again that      =       .  Therefore,
          right  side.  Since   (  ,   ) have  been  defined  as  the   when previous resulting equations done above are
          density of charge transported by bacteria, then this   inserted in Eq. 21 then one arrives at:
          term is processed as follows:                                     (  )      (  )               (  )        
                                                                             = [−           −
                       2    (  )     2      (  )                                                     
                     2  ∫         =      ∫     (  )           (    )                     
                         2                                                    − (1 −  )]  (  ).              (    )
                                                                                         
          where the volume has been assumed to be    =      .
          The  radial  derivatives  are  actually  the  gradient   Thus, one can see that all charges of the right side
          operator that acts onto the electric potential [12]   have a negative sign. Putting apart the total charge,
          given by:                                            then one arrives at:

                                  (  )                              (  )                                       (    )
                           (  ) =    .                 (    )         =    (  ) [−   −      − (   −     )].
                                                                                                    
          With the balance of units and the incorporation of   One can see that the apparition of sign ”-“ on the
          permissivity constant one arrives at:                right side is because the possible existence of a type
                                                               of discharge because the  straightforward solution
                     
                                    2
                         (  )                 (  )
                   2  ∫         =        ∫    (  )             of Eq. 30 yields the familiar negative exponential.
                                                    
                                   2
                        =          ∫      (  )      .     (    )   Electric  interactions  between  compounds  can  be
                              
                                                               measured through the electric force as dictated by
          By which one can identify that in the last equation   classical electrodynamics. To explore this, the total
          one  has  the  field  electric,  thus  one  arrives  at  the   charge  of  bacteria  should  be  explicitly  done,  thus
          divergence theorem , yielding that this contribution   from Eq. 30,
          to the BKS equation is proportional to the square of                                     
          cylindric radius. With this one gets that:                  (  )  = [−             −              − (1 −      )]    ,     (    )
                                                                    (  )                             









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