ðə fˈækt ðæt ɪz nˈɛɡətˌɪv ɪmplˈaɪz ðætðɪ ɛkstɹˈækʃən ʌv pˈɑːɹɾɪkəlz fɹʌmðə sˈɪstəm tə ðə ɹˈɛzɚvwˌɑːɹ ɹᵻkwˈaɪɚz ˈɛnɚdʒi ˈɪnpʊt.
The fact that   is negative implies that the extraction of particles from the system to the reservoir requires energy input.