Journal of the Society of Agricultural Structures, Japan
Online ISSN : 2186-0122
Print ISSN : 0388-8517
ISSN-L : 0388-8517
Volume 37, Issue 1
Displaying 1-2 of 2 articles from this issue
  • Hiroyuki USUDA, Takeo SHIINA, Yutaka ISHIKAWA, Takaaki SATAKE
    2006 Volume 37 Issue 1 Pages 3-9
    Published: June 25, 2006
    Released on J-STAGE: September 05, 2011
    JOURNAL FREE ACCESS
    To develop a random vibration test method based upon actual transport condition and susceptibility of the product against the vibration, validation of obtaining the power spectrum density (PSD) by using a low cost vibration logger and design method of PSD were investigated.
    A low cost three dimensional vibration logger (interval recording type) was subjected to the sinusoidal vibration in vertical direction by using a three dimensional vibrator. PSD data obtained by equipped software gave the lesser level of power in the low frequency range due the limitation of the resolution of frequency. Therefore, in the PSD evaluation by digital Fast Fourier Transformation, attention should be paid not only for the upper limit frequency based upon sampling theory but also for the lower limit frequency.
    To obtain PSD for the simulated transport test, a simple average of the PSD data will give too little power level, whereas selection of the highest level PSD will give the over power level. It is possible to obtain a PSD data which is being considered the damage susceptibility of the product by using a S-N curve. More over, an accelerated test, shortening of the time for the vibration test than the actual transport, is possible by using the S-N curve.
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  • Moisture content and grain size
    Genta KANAI, Katsuhiko TAMAKI, Yuji NAGASAKI, Takaaki SATAKE
    2006 Volume 37 Issue 1 Pages 11-18
    Published: June 25, 2006
    Released on J-STAGE: September 05, 2011
    JOURNAL FREE ACCESS
    A wheat-grain classification method that uses size grading to reflect moisture content was developed for high-moisture-content grains. To grasp the relationship between grain thickness and moisture content and thereby fix the best grading size, the moisture content distribution of each thickness group and the consequent thickness distribution of grains were examined before and after drying. In addition, a rotary grader was used to perform a practical grading test.
    Regarding pre-dried grain thickness, later harvested grain becomes thinner as it dries in the field. However, after drying, the later harvested grains are thicker as a result of their relative maturation. Observations of grain thickness and moisture content using a sieve by the Japanese Food Agency standard indicated that the best sieve size to separate high-moisture wheat grains is 3.0-3.4mm. The resultant two groups have higher and lower moisture contents. Tests using a rotary grader with 3.0, 3.2, and 3.4mm sieves indicated that a 3.2mm sieve is best for roughly equal separation of grains at around 35% moisture content. The grading capacity of high-moisture grain was about 30% of that of dried grain because of its high friction properties.
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