In order to examine the impact sound insulation performance of building floors against heavy and soft impacts such as those of children jumping and running, a method whereby a heavy and impact source (an automobile tire) is dropped is specified in JIS A 1418, in addition to the standard method of using the ISO tapping machine. In order to improve the latter method, a research project has been carried out in the Architectural Institute of Japan. After various trial experiments, a new heavy and soft impact source (a rubber ball, weight: 2.5 kg; size: 183 mm in diameter; impact time: 20 ms) has been developed. In this paper, the basic impact characteristics of the source and the experimental results obtained in field measurements are introduced in comparison to the existing impact sources (automobile tire and the tapping machine).
A committee of Research on the Evaluation of Human Impact of Low Frequency Noise from Wind Turbine Generators conducted a series of physical measurements, laboratory psychological experiments and social surveys of wind turbine noise under the auspice of the Ministry of the Environment of Japan. In this paper, a design of questionnaire used in the survey and a part of the results are introduced. The questionnaire is based on the proposal of the Acoustical Society of Japan, which was planned to make the results of social surveys conducted by various researchers comparable. Social surveys were conducted in 36 sites where wind turbine noise is audible and in 16 sites where wind turbine noise is inaudible. The number respondents were 747 and 332, respectively. The results of the survey are introduced from various viewpoints.
High-resolution differential melting curves of φX174 Y1 and Y2 restriction fragment DNAs, for which the base sequences were known, were measured at various sodium ion concentrations ranging from 195 to 2.3 mM. The curves were resolved into component peaks, and the change in the melting temperature, the change in the area, and the change in the breadth of each peak with change in salt concentration were examined. The locations of the melting regions corresponding to the peaks in the melting curves were assigned based on theoretical calculations of melting curves and stability maps. It was found that as the salt concentration was decreased from the high to the intermediate range, the breadths of the peaks on the low-temperature side decreased whereas those on the high-temperature side remained almost constant, and also the separation between the peaks along the temperature axis increased. Changes in the positions of peaks relative to one another were interpreted in terms of the difference in the free energy increase between a loop state and an end-coil state as the salt concentration decreased.
In order to examine the acoustical condition inside cars, the authors have been performing a series of psycho-acoustical experiments using a 6-channel recording/reproduction system which have been devised to realize 3-dimensional sound field reproduction. As the test sounds, car interior noises during actual running were recorded at a passenger-seat by changing the running conditions and were reproduced through the six loudspeakers which were orthogonally arranged in a semi-anechoic room. The test subjects sitting at the center point of the reproduced sound field were asked to judge the aural impression (noisiness to the car interior noise and its effect on listening to the radio). The experimental results were arranged using various noise indicators.
Lty'sozynie vaTiants lacking sorne of the disulfide bends i-'ere studied in selutions containing TFE Ctritluuroethanol) which is known to jnducc hclical stnicture.The helieal centent induced by the addition ef 5eV, TFE vuried with the Tiumber of remaining S-S bonds, that is to say. it was largest for OSS-yaTiunt.while it was intermediate for 2SS-variants und mlnimized for wild-type.This indicates that rernaining S-S bunds suppress the forniation of excess helical structures, but
