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Volume 41 (2010)
- Issue 4 Pages 156-
- Issue 3 Pages 103-
- Issue 2 Pages 64-
- Issue 1 Pages 1-
Volume 41, Issue 2
Vol. 41, No. 2 (Ser. No. 126)
Displaying 1-4 of 4 articles from this issue
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Yasuyo NISHIMURA, Yasufumi FUKUMOTO, Hiroshi ARUGA, Yasuko SHIMOI2010 Volume 41 Issue 2 Pages 64-69
Published: 2010
Released on J-STAGE: July 07, 2023
JOURNAL OPEN ACCESSA newly developed long-life spectrum conversion film, which converts light from the green light region to the red light region, was investigated for its performance and weatherability. The growth and development of two types of Chinese cabbage and radish grown under the conversion film and non-conversion film (natural light type film) was also investigated. Spectral irradiance of two different thicknesses (60μm and 100μm) of spectrum conversion film was compared to sunlight (non-covering), with the green region decreasing to 0.87 and 0.74 (sunlight=1), respectively, and the red region increasing to 1.06 and 1.11, respectively. The conversion characteristic of the spectrum conversion film was maintained in the nine months after covering the greenhouse. Also, it is considered from the interior weatherability acceleration test that the performances can be maintained for at least five years. The growth of two types of Chinese cabbage increased under the two different thicknesses of conversion films compared with growth under the non-conversion film. The growth of the underground part of the radishes was significantly enhanced under the 100 μm conversion film.View full abstractDownload PDF (1529K) -
Yasushi UEMATSU, Satoshi TANAKA, Hideki MORIYAMA, Sadanori SASE2010 Volume 41 Issue 2 Pages 70-78
Published: 2010
Released on J-STAGE: July 07, 2023
JOURNAL OPEN ACCESSThe present paper proposes the peak wind pressure coefficients for designing the cladding of pipe-framed greenhouses widely used in Japan, based on a series of wind tunnel experiments. Simultaneous pressure measurements are made with a 1:40 scale model of the greenhouse in a turbulent boundary layer simulating the natural winds over typical open-country exposure. Not only an isolated model but also two or three models arranged in parallel are tested and the effect of adjacent structures on the pressure distributions is investigated. The distribution of the peak pressure coefficients is obtained from the point-pressure measurements. Then, the peak pressure coefficients for designing the cladding are discussed based on the area-averaged pressures and the local lift coefficient. The effect of adjacent structures on the peak pressure coefficient is also investigated.View full abstractDownload PDF (3297K) -
─Addition Method of Ammonia Recovered by Vacuum-Induced Aeration System─Fumihito MIYATAKE, Yoshiyuki ABE, Yoshifumi HONDA2010 Volume 41 Issue 2 Pages 79-86
Published: 2010
Released on J-STAGE: July 07, 2023
JOURNAL OPEN ACCESSIn order to produce the compost with high nitrogen contents, ammonia recovered from vacuum-induced aeration composting system was added to compost after the biooxidative phase was finished. The present study investigated how to add the recovered ammonia to compost during the maturation phase. Two addition methods were examined: One was to add a large quantity of recovered ammonia to compost for once at the beginning of the experiments, the other was to add gradually increased amount of recovered ammonia to compost several times during the experiments. Results showed that the addition of recovered ammonia with gradually increased amount had a significant effect on the increase of the ammonium and nitrate-nitrogen contents in compost. In this experiment using this addition method, the nitrification was progressing from the beginning of the experiment and the maximum nitrate-nitrogen content was increased up to about 8.3 g・kg-dm-1. The accumulation of nitrate-nitrogen resulted from the nitrification led to the decreases in compost pH value of 6.5-6.6. As a result, volatilization of ammonia gas was inhibited by low pH and ammonium-nitrogen was fixed with compost. In contrast, when a large quantity of recovered ammonia was added to compost once at the beginning of the experiments, the loss of ammonium-nitrogen increased. Therefore, the addition of recovered ammonia with a large quantity resulted in failure of the fixation of nitrogen to compost.View full abstractDownload PDF (1755K) -
Genta KANAI, Kazuhiro TAKEKURA, Hitoshi KATO, Morio MATSUZAKI, Tomoko ...2010 Volume 41 Issue 2 Pages 87-94
Published: 2010
Released on J-STAGE: July 07, 2023
JOURNAL OPEN ACCESSA rotary size grader designed for rice and wheat grain was used to remove admixtures from grain of rapeseed and sunflower before drying. For rapeseed, the grader with a 1.2 mm width hole was applied to remove admixed particles smaller than the grain. It removed 14% of the admixture from a sample with a 4.2% admixture rate with 1.0% grain loss. The grader with a 2.3 mm round hole was applied to remove admixed particles bigger than the grain. It removed 82.9% of admixtures with 17.7% grain loss. The grader with the 2.3 mm width narrow hole removed 53.2% of admixed particles with 0.0% grain loss. For sunflower seeds, the grader hole width to remove the admixture smaller than the grain was necessarily changed between 2.0–2.4 mm according to the grain size, which varies among years, fields, and growing conditions. The grader with a 5.0 mm width narrow hole was applied to remove admixtures bigger than the grain. It removed 15.2–50.4% of admixtures with 6.6–7.7% grain loss. For both grains, the rotary grader can reduce the admixture ratio to less than 1.0%, but it is strongly affected by the original admixture ratio and the purification processing after drying.View full abstractDownload PDF (2770K)
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