My wife and I were happily living in a nice duplex in a cool area of Pittsburgh till my job went sour. We then moved to Reading, PA for a better job. I got into a apartment complex that is about 25 older buildings in one complex. They advertised that they provide heat. They have one large boiler in each building and they control the boiler. It runs to the registers to every room in the building, and there is no valve or control on the register.
CTD is the abbreviated name for an instrument package that includes sensors for measuring the Conductivity, Temperature and Depth of seawater. The NOAA EOI Plume Studies Group uses a SeaBird 911plus CTD.
Continuous Tone Coded Squelch System (CTCSS) is a generic term used by the mobile radio industry; the technology itself accepts desired signals and rejects undesired ones on a voice radio channel. It's also known under the brand names PL (Private Line) to Motorola users or Channel Guard to GE/Ericsson users.