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.
Consistent condom use can reduce the spread of HIV, but are they the answer to rising rates of other sexually transmitted infections? Despite some inconsistencies in the evidence, studies show that condoms are an effective physical barrier against passage of even the smallest sexually transmitted pathogens.