-Cadmium contamination still occurs in some parts of the world, and its concentrations in the environment are monitored in most countries due to its adverse effects on human health. We herein established yeast (Saccharomyces cerevisiae) reporter assay strains carrying plasmids with the yeast JLP1, SEO1, and CUP1 promoters connected to the bacterial lacZ reporter gene. The strain carrying the high-copy number pESC-JLP1-lacZ reporter plasmid was more responsive to cadmium than strains with other reporter plasmids. This JLP1-lacZ reporter assay strain will be useful for monitoring cadmium contamination in environmental water and soil as a first screening tool preceding official instrumental analyses, because the assay is rapid, easy to handle, and has the ability to process a large number of samples at a low cost.
Noise emitted from wind turbines is composed of aerodynamic and mechanical sound and has directional radiation characteristics. To investigate the horizontal sound directivity around a wind turbine under various wind conditions, field measurements of noise generated from two different wind turbines have been performed over long periods. Wind turbine operational data such as the nacelle direction and rotor rotational speed were collected at 1 s intervals along with corresponding acoustic data. An empirical formula for the directivity correction was derived from the A-weighted sound pressure levels measured at the several receiving points around the wind turbine. We also focused on the amplitude modulation components of wind turbine noise in emission areas and compared the estimated rotor speeds by using measured sound pressure levels with actual values. The results showed that the directivity pattern of the A-weighted sound pressure level for two different wind turbines is almost the same, whereas the frequency dependence of the sound directivity is different for the individual wind turbines. Additionally, the radiation characteristics of wind turbine noise depend strongly on the rotor rotational speed, which can be estimated from the blade-passing-frequency detected by using the amplitude modulation components of wind turbine noise.
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