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Volume 40 (2009)
- Issue 4 Pages 219-
- Issue 3 Pages 159-
- Issue 2 Pages 113-
- Issue 1 Pages 1-
Volume 40, Issue 3
Vol. 40, No. 3 (Ser. No. 123)
Displaying 1-4 of 4 articles from this issue
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Maro TAMAKI, Sadanori SASE, Atsuo IKEGUCHI, Toru AKACHI, Masahisa ISHI ...2009 Volume 40 Issue 3 Pages 159-165
Published: 2009
Released on J-STAGE: December 14, 2023
JOURNAL OPEN ACCESSThe airflow characteristics of eleven anti-insect screens used in the southwest islands were evaluated by means of a wind tunnel. The thread diameter of anti-insect screens ranged from 0.17 to 0.29 mm, and the porosity ranged from 0.25 to 0.68. Wind tunnel experiments indicated that the pressure loss through the screens was a function of porosity. Specifically, the pressure loss increased when the porosity decreased, even if the pores were approximately the same size. For instance, the pressure loss increased to 1.6 times when the porosity decreased by 18 %. It is recommended to examine the porosity, not the pore size, for the airflow characteristics of the anti-insect screens. The pressure loss through a screen was found to be a quadratic function of its porosity for a constant airflow velocity through the screen. Additionally, an examination of the adaptability of previously reported prediction equations for the pressure loss coefficient showed an error of 20 % or more for three screens.View full abstractDownload PDF (1959K) -
Yukimasa NOROSE, Kazunori IWABUCHI, B. SALUDES Ronaldo2009 Volume 40 Issue 3 Pages 167-176
Published: 2009
Released on J-STAGE: December 14, 2023
JOURNAL OPEN ACCESSProduction of animal feed from food waste by controlled the moisture content were investigated. Simple structural equipment was regularly fed with food wastes from a university cafeteria, junior high school and restaurant in the city. Moisture content was controlled at 40 % w.b. and 20 % w.b. in the term of curing period and feed production period, respectively. Temperature, moisture content and pH were measured. Final material was analyzed nutritional components as swine feed and safety. During experimental period, pH was low and curing period pH was less than 5. In addition, since moisture content was controlled 20 % w.b. the aromatic and good handling condition materials were generated. Nutritional components were at the same level as commercial formula feed and the many recycling feed. As to safety, heavy metals, aflatoxin, and pathogenic microbe were satisfied the standards. Therefore, it was thought that the availableness as recycling feed was high. To control the moisture content at 20 % w.b. can reduce the cost for drying and avoid the risk of thermal denaturation. However, it was necessary for investigation that retention time, early decomposition and removal for oil and fat, and prevention of deterioration because the peroxide value was high.View full abstractDownload PDF (2810K) -
Sadanori SASE, Limi OKUSHIMA, Masahisa ISHII, Tadashi TAKAKURA, Makio ...2009 Volume 40 Issue 3 Pages 177-184
Published: 2009
Released on J-STAGE: December 14, 2023
JOURNAL OPEN ACCESSGreenhouse heating using heat pumps has become widespread recently due to soaring oil prices. Due to lack of time, some methods of heating have been implemented without any definite technical background. A typical example is the so-called “Eco-mode” system, which collects energy from air inside the greenhouse, and air passed through an evaporator is circulated between the space above the thermal screen and the glass. In the present study, the consumption of electricity for a system in “Eco-mode” was compared with that of a system in “Normal-mode” which utilizes outside air as an energy source. It was found that the consumption of electricity in “Eco-mode” was approximately 40 % larger than that in “Normal-mode”, and an unanticipated large electricity loss occurred when heat lost to the outside decreased. From heat loss calculations, the system in “Normal-mode” had the largest electric energy utilization coefficient, followed by the system that utilized the air between the outside cover and the inside thermal screen. The smallest coefficient was found for the system that utilized inside air, since this system is equivalent to an electric heater. The coefficient for “Eco-mode” was between the last two systems.View full abstractDownload PDF (2027K) -
Yasushi UEMATSU, 賢嗣 田中, Hideki MORIYAMA, Sadanori SASE2009 Volume 40 Issue 3 Pages 185-194
Published: 2009
Released on J-STAGE: December 14, 2023
JOURNAL OPEN ACCESSThe present paper proposes the external wind pressure coefficients for designing the main wind force resisting systems 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. The distribution of the equivalent static pressure coefficients generating the maximum load effect on the frame are computed by using the LRC (Load Response Correlation) method; the bending moment at the windward column base is taken as the most critical load effect in the analysis. First, a model of the external wind pressure coefficient is provided for the isolated model. Then, the effect of adjacent structures on the pressure distribution is investigated using two or three identical models arranged in parallel. The results indicate that the proposed model of external wind pressure coefficients can be applied reasonably to the plural model cases.View full abstractDownload PDF (2665K)
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