Current produced by thermocouples. My understanding is that the thermocouple voltage is strictly a function of the temperature. Apparently this is called the Seebeck Voltage. Like any voltage source there is an internal resistance associated with it due to real world effects.
HIV/AIDS. Condoms for HIV prevention. Condoms, when used correctly and consistently, are highly effective in preventing HIV and other sexually transmitted infections (STIs). A large body of scientific evidence shows that male latex condoms have an 80% or greater protective effect against the sexual transmission of HIV and other STIs.
In particular, the number of teens who regularly use condoms has increased significantly over the past 10 years. Sex and contraceptive education may be the most effective way to reduce teen pregnancy. However, teenagers generally are uninformed about the availability, efficiency, and choices of contraceptives available.