Abstract: Methods of providing supervising signals to amplifiers of a fiber optic system are described. In the system, traffic signals are carried at one or more traffic signal carrier wavelengths and are amplified by the amplifiers so that they are maintained in strength. Supervisory signals are provided either at two different carrier wavelengths, or at a single carrier wavelength which is, although different from the traffic signal carrier wavelengths, such that the supervisory signal is maintained in strength by the same amplifiers. Supervisory information is provided on the supervisory signal by modulation at a frequency substantially lower than that of a traffic bit rate for detection by detectors located at the amplifiers. A fiber optic system is also described which is adapted to utilize this method.

Abstract: A method and apparatus is used for covering the exposed workface of a landfill with a film. The apparatus includes a compactor rotatably mounted on a frame which is hitched to a tractor. A film, spray and ballast deployer is mounted on the end of the frame for spraying the landfill, deploying the film onto the landfill, and deploying the ballast onto the film. The compactor includes a roller which compacts the waste prior to spraying the landfill and deploying the film and serves as a wheel for the frame. Hydraulics are provided to raise and lower the deployer. In operation, the assembly is pulled by the tractor causing the compactor to compact the waste just prior to the deployer laying the film on the workface and the ballast being deposited onto the film. Additionally, the apparatus is capable of casing the overlapping layers of laid film to adhere to the ballast in between thereby forming a seal between the adjoining layers.