3-NIRVANA-user-guide/3.2-User-interfaces.md

@@ -1097,12 +1097,8 @@ algebraic expression $a^2+b^2+c^2$.
 IC for the shock-cloud interaction problem simulated in a 3D Cartesian
 box given by (x,y,z)=[-1/2,1/2]<sup>3</sup>:
 
-![ic_example2](uploads/e31ebefeb64b91e0ef74d839ebac4de8/ic_example2.png)  
+![ic_example2](uploads/e31ebefeb64b91e0ef74d839ebac4de8/ic_example2.png){width=500px}
 
-$$(\varrho,p,v_x,v_y,v_z,B_x,B_y,B_z)=\left\{\begin{array}{ll}
-(3.86859,167.345,0,0,0,0,2.1826182,-2.1826182) & x<0.1\\
-(1,1,-11.2536,0,0,0,0.56418958,0.56418958) & x\ge 0.1
-\end{array}\right.$$ 
 At **x**=(0.3,0,0) a spherical clump with
 radius 0.15 and density of 10 is embedded and co-moving with its
 surrounding flow under the assumption of pressure equilibrium. 
@@ -1281,10 +1277,11 @@ depends on the type of variable as listed in the following table:
 
 #### BC for the gravitational potential
 
-BC for the gravitational potential $\Phi$ cannot be explicitely set
+BC for the gravitational potential *Φ* cannot be explicitely set
 except when specifying U in `nirvana.par`. Otherwise, the following rule
 is adopted to transform MHD BC types into BC types for $\Phi$:
 
+*Φ*
 | selected BC type |  ⇒  | BC type for *Φ*                        |
 |------------------|:----|:---------------------------------------|
 |                P |     | P (periodicity)                        |
@@ -1295,9 +1292,9 @@ is adopted to transform MHD BC types into BC types for $\Phi$:
 
 In case of von-Neumann conditions (M,A,R) the gradient of potential
 vanishes normal to the corresponding domain boundary, i.e.,
-$\mathbf{e}_n\cdot \nabla\Phi=0$ where $\mathbf{e}_n$ is the unit normal
+**e**<sub>*n*</sub> ⋅ ∇*Φ* = 0 where **e**<sub>*n*</sub> is the unit normal
 vector of the domain boundary. In case of Dirichlet conditions (I,O,D)
-boundary values for $\Phi$ are obtained by a multipole expansion for the
+boundary values for *Φ* are obtained by a multipole expansion for the
 given mass distribution (cf. [physics
 guide](https://gitlab.aip.de/ziegler/NIRVANA/-/tree/master/doc/pdf/PhysicsGuide.pdf)).
 In case of user-defined conditions U the selfgravity solver calls the
@@ -1307,7 +1304,7 @@ function `phiUser()` expecting a user-defined gravitational potential.
 possible. The solver only supports triple-periodic BC when periodic.
 
 When using the screening mass approach for cylindrical/spherical
-problems with $2\pi$-periodicity BC are computed to discretization error
+problems with $2\pi$ 2*π*-periodicity BC are computed to discretization error
 accuracy by the gravity solver itself. In this case above rules do not
 apply and any specified BC are ignored.