Because my email address is attached to some the Jena source code, I quite often get direct email from students seeking help with projects. In general I don't mind this, though I'm sufficiently busy with actual work that I can't offer much direct support. My usual feedback is that most people need to get much clearer what they are actually to do. Often they come with very vague ideas:
I have to complete my project on ontology. Can you please help me to create a Jena interface?
Which gives pretty much nothing to go on. As a UI designer, you need some idea of who you are designing for, and what they care about. Here's my standard advice, which I've given out sufficiently often that it's worth repeating it in public so that I can just refer to it in future!
My core advice would be to get much clearer what you mean by "Jena interface" – (or however you've termed your project) without more context, I don't understand what that means, and I suspect you don't really understand it either.
So my suggestion is: consider a person using your interface when it's completed. Ask yourself some basic questions about them: are they beginners or experts? Are they a programmer, end-user, ontology designer, or what? What are the most important tasks do they need to do in order to succeed in their role? For example, an ontology designer might want to load an ontology file that someone else has created and add their own annotations to it, to fit their customers data needs. Or, a programmer might want to search for an ontology that would help them represent concepts about wildlife for a media catalogue program, so that users of the catalogue can tag consistently. By making this description as detailed as possible, you get a much clearer understanding of your users' needs.
Then ask yourself what are the three most important features of your interface that would make those users' jobs easier. Imagine them sending a twitter message: "Hey, this interface is really cool, it allows me to do X really well!" And that gives you the starting point for your design process.
By the way it doesn't matter if you are only doing this as a student project, not as a real product. Either find a group of real users to work with, or make up some users and jobs for them to do. That way, you'll end up with a more interesting interface, and it will make it much easier for you to write your end-of-project report!
And by the way, specific questions about Jena should be asked on the Jena support email list.