Thanks for getting back to us, I would suggest to use categories to separate this with your public/private blog.
For example :
1. Create following 2 category from backend.
- Cat-public-news
- Cat-public-Studies
Then set the user permission from the category section which user group you would like to give the permission view/create. (screenshot :
http://take.ms/NTxta )
And the global user ACL part as well (screenshot :
http://take.ms/MFTJv ||
http://take.ms/rz42N)
2. Create another new category for private category
- Cat-private-blog
And do the same thing like what i described at above.
Hope this will help.