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.
The only 100% effective way to prevent sexual transmission of HIV and STDs is through abstinence - avoiding all vaginal, anal and oral sex. Using a latex male condom or a female condom can greatly reduce, but not entirely eliminate, the risk of HIV and STD transmission. Abstinence is the only method to completely eliminate the possibility of sexual transmission of HIV or STDs. No. Only condoms reduce the risk of pregnancy, STDs and HIV.