Are there any academic journals that focus on anime/manga? Are there any places that regularly publish anime or manga related academic papers? 

I'd be interested in reading them and possibly submitting one myself.
Mechademia is an annual publication published by Minnesota Press.  It also covers fan practices and other surrounding activities and media of anime/manga

There is currently a call for papers for a conference on Asian Pop Culture, but none for the next edition. The last volume was published in 2014 and they are still active.

Larger conventions occasionally have calls for papers and a good source of finding them is on the Fan Studies Network site. They hold their own conference with cfps annually also. Arguably the largest of these is at Anime Expo

Other resources for finding articles on anime &amp; manga can be found here:


The "Let's Manga" Project , (also here)
Academia.edu
Anime &amp; Manga Studies group