in the last part of the same book the "chosen one" (tycho brahe) tells in a latin poem about a mystery play performed in a forest in scania where he was directly ordered to work more with the astronomy than the alchemy.

How would the previous sentence be correctly capitalized?
Answer: In the last part of the same book the "chosen one" (Tycho Brahe) tells in a Latin poem about a mystery play performed in a forest in Scania where he was directly ordered to work more with the astronomy than the alchemy.
of course during this period he found it hard to keep in touch with developments in relativity theory which took place in germany.

How would the previous sentence be correctly capitalized?
Answer: Of course during this period he found it hard to keep in touch with developments in relativity theory which took place in Germany.
the first step in the overall pm process is making metal powders.

How would the previous sentence be correctly capitalized?
Answer: The first step in the overall PM process is making metal powders.
the collection of data was exclusively performed during the internet - based on the online panel of zapera.com

How would the previous sentence be correctly capitalized?
Answer: The collection of data was exclusively performed during the Internet - based on the online panel of Zapera.com