An Experimental Study on the Performances of Drum Type Centrifugal Ventilators of Varying Axial Lengths

The forms of the runner of the multiblade drum type centrifugal ventilators, of which the “Sirocco” is the best known, and most popularly adopted in our collieries seem somewhat disadvantageous for a uniform flow of air. The air axially sucked in must suddenly change its direction radially in order uniformly to go out from the periphery, but this is impossible unless the air has no moving inertia. Thus more or less eddy formations due to this cause are inevitable with the runner, and the writer observed that the eddy phenomena decreased by shortening the axial length of the runner. But, then, the ratio, between the amount of frictional surfaces for the air, to the cross rectional area in the casing, would increase, thus causing more frictional loss of energy, if assumed that the quantity of air treated is proportional to the axial length of the fan. The purpose of this experiment is to investigate how the fan performrnces change with fans of varying axial lengths, owing to these l wo opposite influences, keeping other conditions as unchanged as possible

U.S.-Japan Quake Prediction Research

For the seventh time since 1964, a seminar on earthquake prediction has been convened under the U.S.-Japan Cooperation in Science Program. The purpose of the seminar was to provide an opportunity for researchers from the two countries to share recent progress and future plans in the continuing effort to develop the scientific basis for predicting earthquakes and practical means for implementing prediction technology as it emerges. Thirty-six contributors, 15 from Japan and 21 from the U.S., met in Morro Bay, Calif.September 12–14. The following day they traveled to nearby sections of the San Andreas fault, including the site of the Parkfield prediction experiment. The conveners of the seminar were Hiroo Kanamori, Seismological Laboratory, California Institute of Technology (Caltech), for the U.S., and Takeshi Mikumo, Disaster Prevention Research Institute, Kyoto University, for Japan. Funding for the participants came from the U.S. National Science Foundation and the Japan Society for the Promotion of Science, supplemented by other agencies in both countries

Seventh U.S.-Japan Earthquake Prediction Research Seminar: Use of Real-Time Earthquake Information for Hazard Warning

For the seventh time since 1964, a seminar on earthquake prediction has been convened under the U.S.-Japan Cooperation in Science Program. The purpose of the seminar was to provide an opportunity for researchers from the two countries to share recent progress and future plans in the continuing effort to develop the scientific basis for predicting earthquakes and practical means for implementing prediction technology as it emerges. Thirty-six contributors, 15 from Japan and 21 from the U.S., met in Morro Bay, California, September 12-14. The following day they traveled to nearby sections of the San Andreas fault, including the site of the Parkfield prediction experiment. The conveners of the seminar were Hiroo Kanamori, Seismological Laboratory, Caltech, for the U.S., and Takeshi Mikumo, Disaster Prevention Research Institute, Kyoto University, for Japan. Funding for the participants came from the U.S. National Science Foundation and the Japan Society for the Promotion of Science, supplemented by other agencies in both countries

Nonvolcanic tremor observed in the Mexican subduction zone

Nonvolcanic tremor (NVT) activity is revealed as episodes of higher spectral amplitude at 1–8 Hz in daily spectrograms from the continuous seismological records in Guerrero, Mexico. The analyzed data cover a period of 2001–2007 when in 2001–2002 a large slow slip event (SSE) had occurred in the Guerrero-Oaxaca region, and then a new large SSE occurred in 2006. The tremor burst is dominated by S-waves. More than 100 strong NVT bursts were recorded in the narrow band of ~40 × 150 km^2 to the south of Iguala City and parallel to the coastline. Depths of NVT hypocenters are mostly scattered in the continental crust between 5 and 40 km depth. Tremor activity is higher during the 2001–2002 and 2006 SSE compared with that for the “quiet” period of 2003–2005. While resistivity pattern in Guerrero does not correlate directly with the NVT distribution, gravity and magnetic anomaly modeling favors a hypothesis that the NVT is apparently related to the dehydration and serpentinization processes

High energy gamma-rays and hadrons at Mount Fuji

The energy spectra of high energy gamma-rays and hadrons were obtained by the emulsion chamber with 40 c.u. thickness at Mt. Fuji (3750 m). These results are compared with the Monte Carlo calculation based on the same model which is used in a family analysis. Our data are compatible with the model of heavy-enriched primary and scaling in the fragmentation region

Particle interactions at energies over 1000 TeV inferred from gamma-families observed at Mount Fuji

Scaling, mean P sub t, high P sub t jets and others at energies over 1000 TeV are discussed on the basis of gamma-family data with sigma E sub gamma 100 TeV, observed at Mt. Fuji (3750 m). These quantities were examined in connection with the primary composition