Journal of the Society of Agricultural Structures, Japan
Online ISSN : 2186-0122
Print ISSN : 0388-8517
ISSN-L : 0388-8517
Volume 18, Issue 3
Displaying 1-7 of 7 articles from this issue
  • Limi MURAKAMI, Sadanori SASE, Takashi TAKEZONO, Masakatsu KOTAKI, Hiro ...
    1988 Volume 18 Issue 3 Pages 4-11
    Published: March 30, 1988
    Released on J-STAGE: September 05, 2011
    JOURNAL FREE ACCESS
    Model experiments have been carried out about the air flow pattern and the temperature distribution of a 1/7 scale poultry house model, in order to get the natural ventilation characteristics in summer, when there is no wind. This study applied the similarity principle of Archimedes number. The poultry house types measured were the one-storey house and the elevated-floor house. The cages of the elevated-floor house were set in the second floor. Several dimensions of the monitor roofs and the saw-tooth roof were tested. The area and arrangement of the openings in the floor of the elevated-floor house were also examined. The results obtained were summarized as follows;
    (1) Air temperature difference between the inside and the outside of the elevated-floor house was 11-26% lower than that of the one-storey house. The elevated-floor house had an influence on the cool air to blow up from the slits in the floor under the cages, concurrently with the air inflow from the opening area of the side walls.
    (2) The temperature difference depended not on the roof type but on the opening area of the roof, that is when the opening area on the side walls was same.
    (3) From a comparison of seven types of dimensionally different monitors, it was found out that the temperature difference decreased with the increase of the monitor width. But if the monitor height was larger than 1/2 of the monitor width, the monitor height was not effective on the temperature difference.
    (4) In the elevated-floor house, two floor types are experimented; one had the slits all over the floor area, and another had the slits opened only under the cages. The condition of temperature and air flow around the cages improved in the latter type.
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  • The Mass Transfer Coefficient of Water on the Body Surface of Swine
    Hirofumi KAWANISHI, Morimasa NAGASHIMA
    1988 Volume 18 Issue 3 Pages 12-22
    Published: March 30, 1988
    Released on J-STAGE: September 05, 2011
    JOURNAL FREE ACCESS
    The author evaluated the mass transfer coefficients of sweat on the body surface of cattle in previous paper. In this paper, these values were determined for swine.
    The author made a one-third scale model of swine weighing 50kg from the relation of live weight to diameter or body segment length. The mass transfer coefficient of a body segment was evaluated using this model and the trunk of live swine. The method of measurement in using this model was the same way as that in the previous paper, but the measurement of the mass transfer coefficient of a trunk of live swine was made according to the method of Nishi et al. developed, using a naphthalene ball.
    The results obtained are summarized as follows;
    1) 21 heads of swine weighing 5-131.8kg were evaluated for the relation between weght and length or diameter of a body segment. It was found that a 50kg live weight is the diverging point due to the drop in elongation percentage of body segmental diameter or length at a live weight above 50kg (Table 2).
    2) Assuming the head, upper arm and thigh to be circular cores, the trunk a cylinder and half sphere, and the fore arm and leg cylinders, we evaluated the body segmental surface area of the swine. The evaluated area for live weight had an error percentage of only -9--4% as determined by Brody's equation (A=0.0974W0.633).
    3) The ratio of body segmental surface area to that of the entire body was approximately as follows: trunk: 67%, head: 10%, upperarm: 3%, forearm: 2%, thigh: 3.5%, and leg: 2% (Table 3).
    4) The relation between Sh/Sc1/3 and Re in the trunk and leg was not affected by swine orientation toward a stream of air, other body segments were affected by this stream when the Reynolds number was low (Table 5).
    5) The mass transfer coefficient of sweat over the entire body surface increased with air stream velocity, but was not affected by swine orientation toward this stream (Table 6).
    6) The mass transfer coefficient of sweat on the trunk of live swine tended to exceed that in experiment using the present model. This was considered due to thoracic movement necessary for respiration (Table 7).
    7) However, swine sweat so little that its significance may be convective heat transfer coefficient can be detemined by the Lewis relationship.
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  • Shoji TAHARAZAKO, Ye-lian MIAO, Sumio HAYASHI, Kunihiko YOSHIHARA, Kan ...
    1988 Volume 18 Issue 3 Pages 23-33
    Published: March 30, 1988
    Released on J-STAGE: September 05, 2011
    JOURNAL FREE ACCESS
    Ventilation drying test of rice and wheat was performed with a pilot model of a heat pump dehumidifier (H. P. D.) under practical applications. The drying efficiency, the unevenness of drying, the energy consumption and cost, and the percentage of cracked rice were investigated. The results can be summarized as follows.
    (1) Drying rate and drying efficiency: For rice harvested during the middle harvesting season, the average drying rate was about 0.17, 0.14, 0.12 (%/hr) when the relative humitidy of drying air was about 54%, 58%, 60%, respectively. For rice harvested during the early harvesting season, it was 0.19 (%/hr) when the relative humidity of drying air was 62%.
    For barley, the average drying rate was 0.2 (%/hr) at 47.5% of relative humidity of drying air, and 0.24 (%/hr) at 46.8% of relative humidity for wheat. Air at a flow rate of 0.33-0.39 (m3/s·t), and temperature of 24.5-31.0°C was used in the all drying tests (Table 3, 4).
    (2) Coefficient of constant rate of drying: There is a constant rate of drying and decreasing rate of drying for batch type deep bed drying condition. The coefficient of constans rate of drying in this study was 0.605-0.651 for rice and 0.521-0.580 for wheat (Table 5).
    (3) Energy consumption and cost: The energy used to remove 1kg of water from grain in this experiment was between 397 and 713 (kcal/kg) at an average of 493kcal/kg. It costed 11.6-20.7 Yen. Compared with that of fire heated drying, it was cheaper. In this case, 38% to 50% of the energy consumption was for the heat pump and the rest was for the blower (Table 9).
    (4) Effect of grain mixing: Turning over of the grain during the drying process caused elimination of the unevenness of drying temporarily, but had little effect on the drying rate. It is suggested, therefore, that mixing after drying has been finished would be more effective (Table 7).
    (5) Humidity of the drying air when the drying is to be completed: In order to prevent the grain from over drying, it is necessary to provide the drying air which has the humidity corresponding to the required grain equilibrium moisture content. It is desired that the relative humidity of the drying air at the end of drying process is 60% for rice, and 50% for wheat (Table 8).
    (6) Low temperature drying and cracked rice: Because the drying temperature was low and there was no over drying, the amount of cracked rice was lower compared to that from fire heated drying and sundrying, especially for the rice harvested during the early harvesting season.
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  • Model Experiment for Winter Ventilation
    Atsuo IKEGUCHI, Yoshiyasu AIHARA, Tomoharu YAMAGUCHI, Sadanori SASE
    1988 Volume 18 Issue 3 Pages 34-48
    Published: March 30, 1988
    Released on J-STAGE: September 05, 2011
    JOURNAL FREE ACCESS
    Assuming winter ventilation requirements, a series of model tests was performed using a 1/3 scale model of a windowless swine farrowing house with slotted inlets and dampers on the side wall. It was proved how the incoming jet and the distribution of air in the building are affected by the following: (1) the temperature difference between the inlet vent and representative point within the building, (2) air change rate, and (3) damper angle. The incoming jet fell above the side paths for all tests. The patterns of temperature distribution of the incoming jet, which the damper angle affected, were shown evidently. Three-dimensional distributions of temperature in the building were shown for all the three items above. In terms of temperature distribution, no problem was observed for the air change rate of 15 times per hour in spite of winter ventilation. According to condition of gases and dust particles and so on, it seems that air change rate can be increased more than the generally recommended rate of 5, 6 times per hour.
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  • Tadao ICHIKAWA, Iwao NOTSUKI, Yasuhiro AOKI, Motoko ICHIKAWA, Tohru FU ...
    1988 Volume 18 Issue 3 Pages 49-57
    Published: March 30, 1988
    Released on J-STAGE: September 05, 2011
    JOURNAL FREE ACCESS
    Three experiments were conducted to ensure the effects of milking machine deformities, high vacuum (40cmHg=53.3kPa) and faulty pulsation on somatic cell count (SCC) and electrical conductivity (EC) of milk. The first experiment was carried out to examine the influence of abnormal high vacuum for 3 weeks, by comparison with that of the normal one (35cmHg=6.7kPa). In the second experiment, the influence of milking under faulty conditions in pulsator ratio and shifting speed of phases was examined for 3 weeks. And, the third experiment was undertaken for 3 weeks to examine the effect of milking under the condition combined with high vacuum and faulty pulsation on SCC and EC. There were several weeks for recovery and control periods before each experiment. An analysis of data was made due to the following two methods: (1) After all quarters were classified into four groups on the basis of their infectious status and SCC level measured during the control periods, the analysis of variance technique was applied to the data from four groups, respectively. The four groups were one group consisting of infected quarters with major pathogens and the other three groups consisting of non-infected quarters with three difference levels of SCC. (2) Analysis of variance in a nested design was made on the difference calculated by subtracting the value at control period from that at treatment period.
    A significant increase in SCC for the infectious quarters group (1) and low SCC level quarters group (4) was found when high vacuum treatment was applied. Although no influence of faulty pulsation treatment appeared in any group, when high vacuum and faulty pulsation treatment were combined, difference in SCC between treatment and control period was significant in all groups except for one with quarters producing milk with 200-500 thousands cells/ml. On the other hand, no significant difference was found in EC for all groups except for the infectious quarters group (1) where an increase in EC was found under high vacuum and faulty pulsation treatment. The result of analysis of variance in the nested design showed that the degree of influence of milking machine deformities on EC is greater among individual cows than among quarters, while the influence on SCC was found among individual cows as well as among quarters. It was suggested that milking machine deformities employed in the present experiments had a greater influence on SCC than EC.
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  • Yukoh OGURA, Takashi MUKAI
    1988 Volume 18 Issue 3 Pages 58-62
    Published: March 30, 1988
    Released on J-STAGE: September 05, 2011
    JOURNAL FREE ACCESS
    A device for spraying wellwater on the inner roof of a greenhouse (water curtain) was first discribed by one of the authors and its excellent heating characteristics have been established on several multispan greenhouses with double, triple and quadruple roofs. This paper describes the comparative analysis of the thermal characteristics of the curved roof greenhouses with and without the water curtain.
    The test house was intermittently sprayed with wellwater and controlled by a simple room thermostat. The control house was installed with tunnels which were covered with double layer films. Both houses were cultivated with strawberry in the flowering stage. The nocturnal ambient mean temperature ranged was 4.4°C to -4.5°C. The test house has successfully maintained the air temperature above 8°C and the soil temperature above 10°C. The water spraying flow rate of 2.7 to 7.2 l/m2hr: floor was able to provide sufficient inside climate conditions for a wide range of outside climate conditions.
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  • Methods of Quantitative Measuring of Solided Things on the Udders
    Denzo SAHARA, Yoshiyasu AIHARA, Tadao ICHIKAWA
    1988 Volume 18 Issue 3 Pages 63-68
    Published: March 30, 1988
    Released on J-STAGE: September 05, 2011
    JOURNAL FREE ACCESS
    To establish a method of evaluatinon work amount in udder preparation, effectiviness of udder cleanning estimated by quantitive measurement of solid matter which would be removed during udder preparation before machine attachment was investigated. The solid matter on the udder were defined as the dirts come mostly from the dungs of cows in the present study.
    Various kinds in degree of dry matter content and amounts of dung were dissolved in the warm water and used as the simulation of washed water to analyse the relationship between amunts of dirts on the udder and the degree in contamination of washed water.
    It was found that the weight of dung removed from udder can be estimated by (1) dry matter left on the filter after filtration of the washed water and (2) COD of the filtrate of the washed water.
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