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Volume 27 (1996 - 199･･･
- Issue 4 Pages 195-
- Issue 3 Pages 111-
- Issue 2 Pages 47-
- Issue 1 Pages 3-
Volume 27, Issue 2
Displaying 1-6 of 6 articles from this issue
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Tihomir KATARDJIEV, Kengo WATANABE, Seishu TOJO, Manzo UCHIGASAKI, Fus ...1996 Volume 27 Issue 2 Pages 47-56
Published: September 25, 1996
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSSeed germination and seedling growth in experimental prototypes and commercially available culturing trays providing different air-access of their open bottoms and different cell depth was observed for Eucalyptus robusta and Pinus densiflora. The experiments aiming at intensive plant growth were conducted in a solar green house with a temperature and humidity of the air automatically controlled. A three factorial experiment with three levels of air-access of the open bottom (100%, 50% and 0%) and three levels of cell depth (130, 70 and 40mm) for commercial trays and a one factor experiment with two levels of air-access for laboratory fabricated trays (Styrofoam) were carried out. When the air-access was investigated F and t statistics testing on plant height produced reached significance for both 5% and 1% level for observed periods. Differences in the plant height produced were not statistically significant for the employed levels of cell depth. A correlation coefficient decreased with decreasing of the cell depth and air-access of open bottom indicating that the tree seedlings of both species grew more rapidly in deeper cell with more air-access of the open bottoms. Laboratory fabricated styrofoam blocks allowed a root penetration in the block material causing difficulties in the subsequent transplanting.View full abstractDownload PDF (1179K) -
The Performance of the Drying device and the Heating Properties of the Agricultural ProductsKentaro MOURI, Huoqing LIU1996 Volume 27 Issue 2 Pages 57-63
Published: September 25, 1996
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSIn order to improve the drying quality of agricultural products and reduce drying cost, a multi utility far-infrared drying device was made. Characteristics of the drying device were measured and heating performances of the agricultural products were investigated.
The following results were obtained:
(1) Among several minutes of heating, the surface temperature of the bar-heater raised to a constant temperature. In order to get a uniform temperature on a sample plate, the heater were placed on the focus of the radial ceiling of the device.
(2) By using the far infrared heater, the surface and internal temperature of the agricultural products were higher than the surrounding temperature.
(3) When the agricultural products were heated, the increasing of sample temperature were different according to the radiated wave length of far infrared rays.
It were available for the drying of agricultural products to use the far-infrared rays which has a high heating efficiency.View full abstractDownload PDF (2068K) -
Takami TAJIRI, Takayoshi AKINAGA, Seishi KAWASAKI, Yoshihiro KOHDA1996 Volume 27 Issue 2 Pages 65-70
Published: September 25, 1996
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSMango is a type of tropical fruit whichis very perishable, and it is necessary to keep cool after harvest. Okinawan grown mango fruits are picked at a fully matured condition and the salable term is short. However, mangoes were classified the chilling sensitive tropical fruits. Qualities of mangoes differ from according to the species, maturity indices, geographical conditions, and so on. Thus, recommendation for storage temperature vary among the commodities. This study was carried out to determine the suitable storage temperature of fully matured mango fruits and green ripe mango fruits. To measure the respiration rate, mangoes were stored at different temperatures. The relationships between storage temperatures and respiration rates of mangoes were analyzed. After that, mango fruits were stored at four different temperatures to evaluate qualities of mangoes during storage.
We conclude from the experiment described above that a low temperature is suitable for keeping the qualities of mangoes. The suitable storage temperature differs according to the maturity, and it was found that 5°C for fully matured fruits and 12°C for green ripe fruits were the storage temperatures to keep the best qualities.View full abstractDownload PDF (738K) -
Using the Specific NIR Absorption Wavelength on Water, Cellulose and SugarTetsuya TANABE, Takayoshi AKINAGA, Yoshihiro KOHDA, Seishi KAWASAKI, Y ...1996 Volume 27 Issue 2 Pages 71-76
Published: September 25, 1996
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe feasibility of predicting the sugar content of Okinawan grown pineapples and mangoes was studied using the specific NIR absorption bands. Therefore, components of pineapples and mangoes were mainly water, cellulose and sugar, the calibration curve of predicting the sugar content of pineapples and mangoes have been made using the absorption bands of water, cellulose and sugar. When 4 specific bands at 958, 978, 918, and 844nm were used to predict the sugar content of pineapple, SEP of sugar content of pineapples harvested in 1992, 1993, 1995 and 1995 were 0.66, 0.55, 0.66 and 0.63, and BIAS were -0.26, -0.26, 0.22 and 0.16. Respectively, in the case of mangoes with 4 specific bands at 958, 978, 918 and 878nm, SEP were 0.70, 0.51, 0.64 and 0.47, and BIAS were 0.19, 0.13, -0.16 and 0.16. Good correlation between chemical analysis and NIR values from using absorption bands on water, cellulose and sugar were obtained.View full abstractDownload PDF (551K) -
Solar photovoltaic system and its operationSeishu TOJO, Kengo WATANABE, Hiroaki KURODA, Mathanee SRIARJ, Makoto K ...1996 Volume 27 Issue 2 Pages 77-84
Published: September 25, 1996
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSSolar photovoltaic (PV) generating system was discussed for supplying the electricity to the electric devices of the solar sludge dryer in this paper. The cost of PV module will be still higher if the PV system is designed according to the installation manuals because the PV capacity is calculated with an average of solar irradiation. To reduce the initial cost of PV system, the area of PV array may be smaller than the standard installation. The followings are affirmed through the experiments on PV output characteristics, solar drying of brewer's grain waste and the operating simulation of the solar dryer.
1. Maximum output of PV module is proportion to radiation incident upon the module. Amount of electricity generated in PV can be predicted if the radiation incident upon the module is calculated. The electric generating efficiency of PV module depends on the terminal voltage of the battery because the PV output changes with the acting voltage.
2. The PV electric system should have a battery to allow the night operation and the smooth action of the motor that needs a strong starting torque. The battery can supply the electricity to the load in the case of continuous bad weather.
3. The electric power required to the electric load depends on the drying sludge mass. To simulate the electric power balance, a simulation model of the PV generating system including the solar drying process should be developed.
4. The minimum area of PV module might be three times larger than the standard in the independent electric power system. To avoid the surplus installation, or, to save the cost of PV module, the operation method, as the fan stops in the night and a lower radiation day time, should be discussed for the system design.View full abstractDownload PDF (858K) -
Kazuo FUJITA, Takaaki MAEKAWA1996 Volume 27 Issue 2 Pages 85-93
Published: September 25, 1996
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSCO2 fixation by a blue green algae, Spirulina platensis, was evaluated using volumetric mass transfer coefficient (KLa). The specific surface area of the cells was measured with an image analyzer, and the specific surface area of the cell was evaluated and statistical distribution of the cell length was analyzed. CO2 mass transfer coefficient kCO2L was evaluated with the specific surface area of the cell (a). The surface area of each cell (ad) was about 5.0 (m2/g-d.m.), and CO2 mass transfer coefficient kCO2L ranged between 0.8×10-4 and 1.0×10-4 (m/day). The value of kCO2L during the linear growth phase was found to decrease to one fifth of the maximum. The distribution of the cell's surface area in the late growth phase (14-th day) also correlated well with the Weibull distribution. It was found that the mixing caused cell destruction.View full abstractDownload PDF (2065K)
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