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Volume 34 (2003 - 200･･･
- Issue 4 Pages 249-
- Issue 3 Pages 193-
- Issue 2 Pages 91-
- Issue 1 Pages 1-
Volume 34, Issue 1
Displaying 1-6 of 6 articles from this issue
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Heat balance analysis of a space in semi-undergroundKazuo MORITA, Fumihiko TANAKA, Richard L. URASA2003 Volume 34 Issue 1 Pages 1-9
Published: June 25, 2003
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSIn order to overcome severe agricultural environments in Kagoshima area such as falling volcanic ash, typhoons and high temperature in summer season, a concept of underground plant cultivating system was proposed. A space in semi-underground with sunlight collector was designed and constructed to investigate the feasibility of underground agriculture on a practical scale. Air temperature of the space in semi-underground and soil temperature in underground were measured. Air temperature in a plastic greenhouse on the ground was also measured and compared with that of the space in semi-underground. The air temperature of the space in semi-underground was very stable in all the year round, and there was little difference of temperature between daytime and nighttime. Heat balance of the space in semi-underground was discussed. The heating and cooling load of the space in semi-underground was estimated and the energy load was compared with that of the plastic greenhouse on the ground. The space in semi-underground was considered to be valid for controlling and keeping stable air temperature and saving energy.View full abstractDownload PDF (2489K) -
Development of basic experimental grading deviceSheng Wei CHANG, Osamu FUJIOKA, Sadao OMORI, Osamu SAKATA, Kangquan GU ...2003 Volume 34 Issue 1 Pages 11-19
Published: June 25, 2003
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSA basic experimental grading device aiming at development of a grading machine for Chinese dried green raisins was made on a trial basis.
The grading discrimination of dried rasins being transported by a belt conveyor using a color image sensor and a digital fiberoptic sensor clearly showed that the accuracy of grading by the color image sensor was not affected by conveyance speed. On the other hand, the accuracy of the digital fiberoptic sensor was dependent on conveyance speed.
Based on the results of these experiments, an experimental grading device for dried green raisins was able to efficiently separate raisins into three grades: excellent, fair and substandard. The experimental grading device using a color image sensor for grade detection was able to make a 95% or higher comprehensive discrimination.View full abstractDownload PDF (3029K) -
Possibility of collecting emitted ammonia using vacuum-type aerationYoshiyuki ABE, Naoki FUKUJYUU, Nobuo ITO, Mikio KAMO2003 Volume 34 Issue 1 Pages 21-30
Published: June 25, 2003
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSWe examined the conditions of ammonia generation during composting and the possibility of collecting ammonia with vacuum-type aeration under the 16 sets of composting conditions decided by the addition of materials to adjust the moisture level of feces and moisture levels of the raw materials. Peak ammonia generation appeared when the compost was at a high temperature in the early stages of composting. Ammonia generation then rapidly decreased for 1 or 2 days after peak ammonia generation. When continual aeration was changed to intermittent aeration at ammonia generation, unidentified nitrogen in the nitrogen balance increased. Thus, we supposed that ammonia was emitted from the compost surface at the cessation of aeration. The rate of the nitrogen shift to the outside of raw materials during the experiments increased in following order; Only Feces or + Rice Hull>+Saw Dust>+Treated Compost. When the rates were estimated as eliminated nitrogen mass from the excreta of 1 milking cow for 1 day, the rates increased in following order; +Treated Compost>+Rice Hull>Only Feces>+Saw Dust. Thus, the addition of treated compost 65% moisture condition caused the greatest nitrogen shift from the compost: 97.0gN/cow·day.View full abstractDownload PDF (1123K) -
Basic experiment to analyze thermal environment of the sunlight greenhouseTomoharu YAMAGUCHI, Takeshi KUROYANAGI, Qingyun CHEN2003 Volume 34 Issue 1 Pages 31-37
Published: June 25, 2003
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe energy saving sunlight greenhouse is the most successful and unique facility of protected horticulture in China. Detailed experiment was introduced to analyze the basic mechanism forming thermal environment in the sunlight greenhouse. Solar radiation transmissivity of roof film was about 60%. Temperature differences between inside and outside-air were over 10°C during night without supplemental heating. Heat transfer rate from each wall and floor-soil to inside-air were about 68% from soil, 23% from north-wall and each 3 to 6% from east and west-wall of the total heat, respectively. During night, north-wall emitted about 30% of heat preserved by solar incident during the daytime. More improvement for the thermal property of walls is necessary to modify the thermal environment in crop production.View full abstractDownload PDF (2420K) -
Basic mathematical model predicting thermal environment of the sunlight greenhouseTomoharu YAMAGUCHI, Takeshi KUROYANAGI, Genta KANAI2003 Volume 34 Issue 1 Pages 39-47
Published: June 25, 2003
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSSunlight greenhouse is a typical energy-saving greenhouse widely used in north China. This type of greenhouse has only one transparent roof facing to south direction and solid walls in direction of north, east and west. Those walls and the floor soil play a roll as a heat storage during daytime, and those stored heat and the thermal curtain on the roof allow to keep the inside environment adequate for crop growth without or with less supplemental heating during night in winter season. In this study, a basic model is developed to simulate thermal environment of the sunlight greenhouse without crop, using energy and mass balance equations. The validation of the model is performed with the measurement data at the sunlight greenhouse of China Agriculture University (CAU) in Beijing. The greenhouse air temperature, relative humidity and other temperature of the greenhouse components are generally predicted well except the north wall, whereas the partial opening of the film to prevent overheating causes unexpected change of ventilation rate and then discrepancy between predicted and measured value during the daytime. Secondary simulation is also carried out varying the number of air exchange at several intervals and the result shows that the model may have further accuracy by introducing proper air exchange rate.View full abstractDownload PDF (967K) -
Griffiths ATUNGULU, Yoshio NISHIYAMA, Shoji KOIDE2003 Volume 34 Issue 1 Pages 49-58
Published: June 25, 2003
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSAnalysis of condensation in long grain rough rice (c. v. L201) under various air temperatures (14°C, 20°C, 26°C and 32°C) and relative humidity (40%, 60%, 80% and 98%) was performed. Based on simulation of the heat and mass balance during condensation, models for estimation of condensation amount were established. By applying drying theory of the Sphere drying model, adsorption equilibrium moisture content Me and drying constant K were evaluated and continuous grain moisture changes deduced from which the adsorption and dew formation were evaluated. Computed results compared well with experimental results. Condensation amount depended on the grain initial temperature, moisture content and air conditions. Condensation on rough rice grain initially at 17.8% moisture content (w. b.), and air temperatures 14°C, 20°C, 26°C and 32°C corresponded to hue values 31°, 28°, 27° and 26° respectively at a constant relative humidity of 80% (initial grain hue value 33°) thus indicating incidences of dew formation on the grain surface.View full abstractDownload PDF (1054K)
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