A polyacetal resin composition comprises a polyacetal resin, and a polycyclic aromatic carboxylic acid hydrazide or a polycyclic aromatic carboxylic acid hydrazide having a substituent. The proportion of the polycyclic aromatic carboxylic acid hydrazide may be about 0.001 to 20 parts by weight relative to 100 parts by weight of the polyacetal resin. The polyacetal resin composition may further comprise at least one member selected from an antioxidant, a heat stabilizer, a processing stabilizer, a weather (light)-resistant stabilizer, an impact resistance improver, a slip-improving agent, a coloring agent, and a filler. With the use of such a resin composition, stability of a polyacetal resin is improved, and formaldehyde emission is inhibited.
The invention provides a sensing system for sensing process conditions within an ultrasonic process tank that includes process liquid, the liquid being subjected to ultrasound produced by transducers coupled to a generator. The sensing system includes an enclosure for housing a sample liquid, the enclosure passing ultrasonic energy from the process liquid to the sample liquid, the sample liquid being responsive to the ultrasonic energy, and at least one sensing device within the sample liquid, the sensing device generating signals indicative of characteristics of the sample liquid. The sample liquid includes materials adapted to produce chemiluminescence in response to the ultrasonic energy. The at least one sensing device includes a photo sensor for sensing the produced chemiluminescence and generating signals in response to the produced chemiluminescence.
The invention utilizes multiple frequency ultrasound generators driving multiple frequency harmonic transducer arrays at sweeping frequencies. Generator signals that increase cavitation efficiency and that have successive time periods with predominantly stable cavitation and predominantly transient cavitation further improve the performance of the cleaning, microbiological inactivation, sonochemistry or processing systems. Probes that monitor the ultrasound and feedback the information to the generator provide consistency of process.
A polyacetal resin composition comprises a polyacetal resin, and a polycyclic aromatic carboxylic acid hydrazide or a polycyclic aromatic carboxylic acid hydrazide having a substituent. The proportion of the polycyclic aromatic carboxylic acid hydrazide may be about 0.001 to 20 parts by weight relative to 100 parts by weight of the polyacetal resin. The polyacetal resin composition may further comprise at least one member selected from an antioxidant, a heat stabilizer, a processing stabilizer, a weather (light)-resistant stabilizer, an impact resistance improver, a slip-improving agent, a coloring agent, and a filler. With the use of such a resin composition, stability of a polyacetal resin is improved, and formaldehyde emission is inhibited.