You Do Need power plug adapter while traveling from Yemen to Dominica.

Here is Why You Need An Adapter

The outlet and plug type used in Dominica are D and G and in Yemen are A, D and G. This is how they look like.

Yemen

In Yemen, outlets of type A, D and G are in use.

Type A

Type D

Type G

Dominica

In Dominica, outlets of type D and G are in use.

Type D

Type G