How to say correctly about sphere of my scientific interests?
How to say correctly about sphere of my scientific interests? Is it ok to use "sphere" or should it be - "scope"? and "scientific" or "research"?
How should it be continued: "... is ..." or may be "lies in (some area)"?
I need to make a small speech about my thesis and i'm not sure how to begin and how to say this correctly.
Thank you.

Question

How to say correctly about sphere of my scientific interests?
How to say correctly about sphere of my scientific interests? Is it ok to use "sphere" or should it be - "scope"? and "scientific" or "research"?
How should it be continued: "... is ..." or may be "lies in (some area)"? 
I need to make a small speech about my thesis and i'm not sure how to begin and how to say this correctly.
Thank you.

Answer

We say: FIELD of interest.
This lies within/outside my field of interest.
The word "field" does not imply measure.

"Scope" refers to the actual content, and implies "measure".
This topic is beyond the scope of this book.
The scope of my research is.....

"Sphere of interest" is OK, but it is rigid. A field is open to expansion. A sphere is closed.

Answer

Here are more tips and examples of how to write thesis statements
http://www.italki.com/knowledge/page/TIPS%20FOR%20WRITING%20A%20THESIS.htm

Answer

You can say:
 My  sphere of my scientific interest lies in ..............
The main scope of my thesis looks at the notion that................
In my thesis I will set out to prove that .................
I will do this by.....................................
My research includes......................................

Answer

The area of activity is the "sphere". The depth of activity is "scope". It is all right to say "scientific research". Don't worry about saying "lies". Just say "is". Keep things simple.