Repeating abbreviation in body text if already in chapter/section title
Just my opinion, but normally I wouldn't include the abbreviation in a title or chapter heading. Instead, I would introduce the abbreviation in "normal" text. So in your example, I would change the heading to 


  Chapter 4 - Results of Differential Scanning Calorimetry


but leave the rest as you have it.

An exception would be if this is a well-known abbreviation, so common that people tend to forget what it stands for. In this case, not including it might actually be confusing. For example, if a heading mentions "Internet protocol address", it might take me a split second to realise you're talking about an IP address!