The internal energies of the system are constantly changing.

Internal migrations have increased in recent years.

Interest rate swaps are commonly used by financial institutions to manage their exposure to interest rate fluctuations.

The police are investigating several people of interest in the case.

The police are investigating several persons of interest in the case.

He acted against the company's best interests, showing an adverse interest.

The two companies had adverse interests in the outcome of the merger.

The adverse interest rule is a legal principle that prevents a person from acting in their own self-interest when they have a duty to act in the best interest of another party.

I need to renew my internal passport.

Citizens in some countries are required to carry their internal passports at all times.