Phosphates-Containing Interpenetrating Polymer Networks (IPNs) Acting as Slow Release Fertilizer Hydrogels (SRFHs) Suitable for Agricultural Applications.

Novel, phosphorus-containing slow release fertilizer hydrogels (SRFHs) composed of interpenetrating polymer networks (IPNs) with very good swelling and mechanical properties have been obtained and characterized. It was found that introducing organophosphorus polymer based on a commercially available monomer, 2-methacryloyloxyethyl phosphate (MEP), as the IPN's first component network results in much better swelling properties than for a terpolymer with acrylic acid (AAc), 2-methacryloyloxyethyl phosphate (MEP) and bis[2-(methacryloyloxy)ethyl] phosphate (BMEP) when the same weight ratios of monomers are employed. The procedure described in this paper enables the introduction of much larger amounts of phosphorus into polymer structures without significant loss of water regain ability, which is crucial in the application of such materials in the agricultural field.

Tinnitus and impulse noise-induced hearing loss in drop-forge operators.

Tinnitus is frequently accompanied by noise-induced hearing losses, and perhaps as it is assumed--particularly with those arising from exposure to impulsive types of noise. In order to explain it and to estimate a prevalence of tinnitus in the industrial, impulse noise workers the group of 261 drop-forge operators exposed to impulses with peak levels of 135 dB versus 169 age-matched controls was subjected to otological and audiometric examination, and then the complaints for tinnitus in both groups have been analysed. The prevalence of tinnitus, highest in operators with longer exposure duration (> 10 years) was found in 184 individuals (70.

[A permanent noise-induced shift in the auditory threshold in textile industry workers].

Hearing thresholds have been measured in 236 cotton weaving mill workers (124 women: average age 42.5 +/- 11.2 years, average length of employment 19.

[Measurement of the temporary auditory threshold shift (TTS) for evaluation of the degree of noise hazard].

Long-term investigations of noise in coal mines enhanced the need to take measurements at work stations posing high risk of methane explosion. To facilitate evaluation of noise hazard at the workplace in coal mines, attempts have been made to apply TTS measurements. Measurements of TTS taken within 3 to 5 minutes after cessation of noise exposure in industrial conditions made it possible to evaluate equivalent sound level.