Novel PDF inhibitors and novel methods for their use are provided. The biodegradable polymer comprises a repeat unit selected from the group consisting of glycolic acid, lactic acid, hydroxyalkanoic acids, hydroxybutyric acid, hydroxyvaleric acid, caprolactone, p-dioxanone, trimethylene carbonate, butylene succinate, butylene adipate, monosaccharides, dicarboxylic acid anhydrides, enantiomers thereof, and combinations thereof. An average value is generated in response to the plurality of fly height measurements, and a first control value is generated for a first head based on the average value and the fly height measurement for the first head. Thus, the monolithic refractory material is filled and deposited in the damaged portion under remote control. Here, even when air bubbles enter into the cleaning liquid supplied to the sponge, the air bubbles are discharged to the outside through an air discharging hole formed in the holder. The nosecone assembly has a flexible structure which may change configuration to expose the second set of members after insertion into the second conduit and to allow removal of the nosecone after deployment.