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Volume 17 (1986 - 198･･･
- Issue 3 Pages 4-
- Issue 2 Pages 3-
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Volume 17, Issue 2
Displaying 1-7 of 7 articles from this issue
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Model Experiment for Summer VentilationAtsuo IKEGUCHI, Yoshiyasu AIHARA, Tomoharu YAMAGUCHI, Sadanori SASE, M ...1986 Volume 17 Issue 2 Pages 3-15
Published: December 30, 1986
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe proponent of this study built a 1/3 scale prototype model of a windowless swine breeding house that was constructed with slotted inlets and dampers on the side wall. Air was admitted through these inlets and discharged throgh duct oulets at the center of the ceiling.
This study was aimed at finding relationship between the velocity or direction of incoming air movement, and the influence of the “pen and sow” conditions upon air mnvement. Assuming summer ventilation requirements, tests were conducted by applying the similarity principle of Archimedes number. The results are the following:
1) The angle of incoming air varies from 60° to 70° for all tests.
2) The dimensionless velocity of air movement was less than 0.2 in more than 90% of the measured area, and it was noted that damper angle rather than inlet velocity provides an influence on air flow pattern.
3) The condition when the damper angle was 45° and the inlet velocity was 4.5m/s was more suitable for summer ventilation than other damper angle values.View full abstractDownload PDF (1267K) -
Shigeki KATSURA1986 Volume 17 Issue 2 Pages 16-23
Published: December 30, 1986
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSSnow loads on the roofs of structures for agricultural use have been discussed using return period expectation of snow cover depth obtained statistically.
Statistical properties of the annual snow cover depth of the ground obtained from eighty-nine points in Hokkaido were analyzed. Thomas plot technique with Gumbel's least squares method offered comparatively better return period expectation values for most of the points. Hazen plot technique with Gumbel's moment method was also available.
By means of the statistical properties obtained, return period expectation corresponding to fifteen years and fifty years which are the assumed life of temporary structures and of general structures, were calculated. The fifteen year return period expectation of snow cover depth was about 75 to 89% of the fifty year return period expectation.
Snow loads on the roofs were calculated according to the Japanese Building Standard and Design Recommendations for Loads on Structures. Assuming that the life of the structures for agricultural use is fifteen years and if we use a fifteen year return period expectation for snow cover depth to calculate loads on roofs, snow loads can be reduced about 20% compared to the loads for general structures.View full abstractDownload PDF (1114K) -
Yasuhiko SASAKI, Jin YOSHIMURA, Jun DOHKOSHI1986 Volume 17 Issue 2 Pages 24-33
Published: December 30, 1986
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSConcrete stave silos are “discontinuous” wall structures which are cylindrically assembled from precast concrete units (staves) and held together by exterior adjustable steel hoops (rods). To clarify the dynamic response characteristics of these stave silos and the effects of stored materials, a series of shaking table tests was conducted using a 1/6-scale silo model and each 1.2m3 of brown rice and wet sawdust. An earthquake simulation test was also carried out in which the peak table acceleration was gradually increased.
Based on the experimental results, the main conclusions can be drawn as follows:
1) The vibration characteristics of stave silos change significantly by filling stored materials; in general, resonant frequencies are reduced and the peak response ratio decreases. However, the effects of stored materials are remarkably different according to the variety of stored materials.
2) The strain response of rods hooping the wall is associated with induced circumferential mode shapes, especially oval mode shapes, rather than the acceleration response.
3) Stave silos filled with stored materials show nonlinear earthquake response characteristics, namely, the acceleration response ratio decreases as the input acceleration is increased.
4) In the earthquake simulation test, although several small cracks were observed near the horizontal joints of staves, no critical damages such as the rupture of rods and the collapse of the wall occurred. This result demonstrates the considerable earthquake resistance of stave silos.View full abstractDownload PDF (3349K) -
Measurements of Water Vapor and Sensible Heat Productions in a Dairy BarnShin-ichi URANO, Shyusaku KATAYAMA, Shinji HOSHIBA, Jun DOHKOSHI1986 Volume 17 Issue 2 Pages 34-48
Published: December 30, 1986
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe amounts of water vapor and sensible heat productions were estimated from the analyses of heat and water vapor balances in an insulated and mechanical ventilated daily barn. The results were summarized as follows;
(1) The amounts of water vapor production were stable values of approximately 30kg/h at the time of low ventilation rate when the only two fans moved but they were showed two patterns of values, higher and lower than 30kg/h, at the time of high ventilation rate when the five fans moved simultaneously. While, the amounts of sensible heat production were from 40, 000kcal/h to 50, 000kcal/h at the time of low ventilation rate, but at the instant when the ventilation rate changed from low rate to high rate it showed a pattern of high values reaching 70, 000kcal/h-100, 000kcal/h.
(2) It was considered that the changes of the amounts of water vapor production at the time of high ventilation rate were apparent changes due to incomplete air mixing but the changes of the amounts of sensible heat production contained actual changes caused by the decrease of air temperature in addition to these apparent changes.
(3) Both the amounts of water vapor and sensible heat productions were fluctuating in short time but their daily mean values were in agreement with the data of Yeck et al. (1959).
(4) The mean convection heat transfer coefficient of the inner surface was 2.62kcal/m h°C and the mean overall coefficient of heat transmission of the structure was 0.273kcal/m h°C. The value of the mean overall coeficient were in agreement with the value obtained from R-value data of building materials.View full abstractDownload PDF (1775K) -
Mathematical Method for a Lumped Parameter SystemShin-ichi URANO1986 Volume 17 Issue 2 Pages 49-53
Published: December 30, 1986
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSDownload PDF (522K) -
Environmental Characteristics in WinterShyusaku KATAYAMA, Shin-ichi URANO, Shinji HOSHIBA, Jun DOHKOSHI1986 Volume 17 Issue 2 Pages 54-58
Published: December 30, 1986
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSDownload PDF (656K) -
1986 Volume 17 Issue 2 Pages 69
Published: 1986
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSDownload PDF (124K)
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