The objective of this study was to verify the level of knowledge of users regarding the waste of electrical and electronic products generated by them. Therefore, a qualitative research was implemented, with an exploratory-descriptive objective. 150 questionnaires were sent to users residing in four Brazilian capitals, with a response rate of 91.33%. Overall, 30% of users “infrequently” (PF) segregate waste; 6.57% “very often” (MF) have already looked for an appropriate point of disposal of electronic waste. The city of Maceió-AL has 52.78% of users who “never” (N) disposed of their waste at an appropriate collection point against the same percentage for São Paulo-SP who “often” (F) did so; 29.20% “infrequently” (PF) thought of somehow reducing the amount of waste generated; 91.97% of users “never” (N) have heard about or have unsatisfactory knowledge about the existence of the National Solid Waste Policy – NSWP. Regarding this last question, there was no significant difference between the respondent users with high school and higher education levels.

In this paper, we consider a class of conformally flat spaces that includes the space forms as well as the doubled Schwarzschild space, and, we will prove an extension of Jellett's theorem. Next, we build an example, where the extension of Jellett's theorem does not hold. We also prove a Heintze-Karcher-type inequality and we presented a one-parametric family of conformally flat spaces, all distinct from space forms, where it holds a Heintze-Karcher-type inequality.