Archive - Abstract

Vol.44 No.1 (March, 2013)

  • Original (Japanese)
  • Study of Microwave Pretreatment on Oil Expression Facilities - Investigation on Continuous Heating of Rapeseed using the Rectangular Waveguide Microwave Applicator -
  • Hitoshi KATO, Yuichi KOBAYASHI, Wataru IIJIMA, Kazuhiro TAKEKURA, Kazuto SHIGETA and Kenichi YAKUSHIDO
  • We built a prototype rectangular-waveguide microwave applicator to heat rapeseed in a continuous process for the pre-treatment of rapeseed for oil expression in a press. The short-circuit plate of the waveguide was moved back and forth by a quarter of the guide wavelength at a frequency of 0.5 Hz to form an oscillating electric field in the applicator. While the plate was being moved, the rapeseed was irradiated. This method could heat rapeseed up to 115±4 ℃ continuously at a throughput of 35 kg/h. In the following oil expression test, with a choke opening of 7.5 mm, the oil recovery rate increased from 22.6 % without heating to 28.4 %. The acid value and oxidative stability of the oil showed no major changes, and the content of chlorophyll tended to be higher. These results show that the technique is effective as a pre-treatment for oil expression with a small-scale press.

Keywords: rapeseed, rectangular-waveguide microwave applicator, continuous heating, oilseed press


  • Original (Japanese)
  • Effect of Linoleic Acid and Other Nutrients on the Fatty Acid Composition of Back Fat during Pig Fattening
  • In this study, the flesh of 406 three-way cross hybrid pigs was prepared for tests performed in the laboratory to examine the influence of nutrient intake on the fatty acid composition of pork back fat. Pigs for fattening weighed 65 kg at the beginning of the tests and 112 kg at the end. Results showed the average value of 5-6 pigs for each feeding group was 77 pigs. Nutrient intake during the study period included 2249 g/d of total digestible nutrients (TDN), 399 g/d of protein, 111 g/d of crude fat and 1794 g/d of nitrogen free extracts (NFE). Individual fatty acids were palmitic 18.3 g/d, stearic acid 5.2 g/d, oleic acid 37.9 g/d, linoleic acid 43.7 g/d and endogenous fatty acids 61.4 g/d. NFE, crude fat, palmitic acid, oleic acid and linoleic acid showed significant correlations between the fatty acid compositions of body fat and intake of nutrients. Especially linoleic acid intake was significantly related to the fatty acid composition of body fat. Increasing the intake of linoleic acid, increased linoleic acid in the body fat and conversely decreased endogenous fatty acids. If the intake of linoleic acid was less than 45 g/d, C18:2/C18:0 composition did not change and showed very little effect was seen in hardness of the fat. However, even with reduced intake of linoleic acid, the essential fatty acid linoleic acid accumulated to 7 % in the body fat. On the other hand, TDN and crude protein intake did not correlate with fatty acid composition of body fat.

Keywords: pig, nutrient intake, back fat, fatty acid composition, linoleic acid


  • Original (Japanese)
  • Study on Pretreatment by Electrochemical Oxidation on Anaerobic Digestion of Waste Milk and Dairy Manure
  • Gen YOSHIDA, Ikko IHARA, Kiyohiko TOYODA and Kazutaka UMETSU
  • Effect of pretreatment by electrochemical oxidation on anaerobic digestion of waste milk and dairy manure was investigated in this study. Dairy farming discharges waste milk with dairy wastewater from a milking parlour. Anaerobic digestion is a major treatment method for manure and wastewater in livestock area. Milk fat is considered to be the main limiting component of the kinetics of dairy waste anaerobic digestion. It is known that the ling-chain fatty acids (LCFAs) that are formed during the biodegradation of milk fat inhibit anaerobic bacteria. We discussed the effect of electrochemical oxidation as a pretreatment process on anaerobic digestion of waste milk. Concentrations of LCFAs in milk were decreased by electrochemical treatment using a DSA anode. The inhibition was observed on anaerobic digestion with 50 % inoculum, 35 % dairy manure and 15 % non-pretreated milk. The methane production was increased on anaerobic digestion by electrochemical treatment of milk using a DSA. The results suggested that anaerobic biodegradability for waste milk was improved by electrochemical oxidation using DSA.

Keywords: anaerobic digestion, electrochemical oxidation, waste milk, milk fat, LCFAs, pretreatment


  • Original (Japanese)
  • Investigation of Hot Air Paddy Drying by the Recirculating Batch Dryer Using Hot Water Created from the CO2 Refrigerant Heat Pump Water Heater
  • Takahiro NODA, Yasuyuki HIDAKA, Mio YOKOE, Waichiro MATSUDA and Daisuke WATANABE
  • For the energy saving of grain drying by the recirculating batch dryer, we designed the grain drying system for 500 kg of recirculating batch dryer using heat pump. The main structure of this system is that the hot air for the grain dryer was generated by CO2 refrigerant heat pump water heater and the water-to-air heat exchanger. The chief characteristic of this system is that the system has a hot water storage tank, and the stored hot water acts as a heat-storage medium for grain drying. For the continuous grain drying even in a defrost period, we attempted to use the stored hot water and avoid the trouble due to the frequency of frost and defrost concerned in a low temperature condition.
  • For paddy drying, the drying speed was 1.0 %w.b./h, which is comparable to that of the conventional reciculating batch dryer using a kerosene burner. The increasing of cracking did not occur at a high level. The specific energy consumption was 2.6 MJ/kg・H2O, and the CO2 emission per 1 kg of moisture extraction was 3.1x10-4 t・CO2/kg・H2O, which are 54 % and 23 % lower than that of an average reciculating batch dryer using a kerosene burner, respectively. The average of ambient temperature was 15.4 ℃ and COP of the heat pump unit was 3.2. Our results confirm that our system can maintain the conventional operating efficiency, and at the same time, it cha cut energy consumption and contribute to reducing greenhouse gas emissions, providing the energy saving performance of the heat pump.

Keywords: recircurating batch dryer, heat pump, specific energy consumption, CO2 emission, heat-storage, frost formation, defrosting


Vol.44 No.2 (June, 2013)

  • Original (Japanese)
  • Fertilizer Nutrients and Arable Land Application of Distillation Wastes Discharged from Bio-Ethanol Production Made from Different Dicotyledonous Materials
  • Masayuki TANI, Taku KATO, Daigo AIUCHI, Fumihito MIYATAKE, Masanori KOIKE and Ken TOKUYASU
  • Fertilizer nutrient composition and nitrogen mineralization of distillation wastes discharged from bio-ethanol production made from different dicotyledonous materials (sweet potato, potato, and sugar beet) were investigated. Also, the effects of their arable land application on crop growth and nutrient uptake through pot and field experiments were examined. The distillation wastes from bio-ethanol production contained high concentration of fertilizer macro and micro nutrients which were available for crop plants. The nitrogen mineralization and nitrification processes were distinctly influenced by raw materials. Waste application for spinach in the pot experiment indicated that the wastes were effective to supply alternative fertilizer nutrients and fertilizer efficiencies of phosphate and potassium in the wastes were more than 100 %. The alternative effects of the distillation wastes made from starch-potato upon field application for food-potato production were also observed distinctly, suggesting that the wastes from bio-ethanol production should be used effectively through arable land application.

Keywords: bio-ethanol, distillation waste, dicotyledonous material, fertilizer nutrient, nitrogen mineralization, cultivation experiment, potato yield


  • Original (Japanese)
  • Determination of Astringent Fruit in ‘Le Lectier’ Pears Using Visible and Near-infrared Spectroscopy and Neural Network
  • Kenichi TAKIZAWA, Kazuhiro NAKANO, Shintaroh OHASHI, Masaru HIROI, Shuji CHINO, Tatsuya MATSUMOTO, Yasuhide YAMAZAWA and Kiyohide KOJIMA
  • It is impossible to distinguish the astringent fruit in ‘Le Lectier’ pears by visual inspection. This study aimed to develop nondestructive determination of the astringent fruit and quality assurance of the intact fruit using neural network classification, visible and near-infrared spectroscopy. For thin study, 51 pears harvested in Sanjo City and 46 pears harvested in Tsukigata area of Niigata City, 97 pears in all were collected. The recognition ratio was established by neural network learning and validation repeatedly using leave-one-out cross validation. The average recognition ratio was 81.1 % when the neural network was discussed using 15 hidden layer units and set an error goal to 0.11 and calculated by 10 times cross validation.

Keywords: visible and near-infrared spectroscopy, first derivative absorption, cross validation, astringent fruit, turbidity, neural network, nondestructive


  • Original (Japanese)
  • Effect of Fruit Load on the Growth and Yield of Long Term Greenhouse Tomato
  • Kentaro TAMAKOSHI and Haruhisa INDEN
  • We investigated the effect of fruit load on the growth and yield of long term greenhouse tomato (Solanum lycopersicum L. cv. Elegance) to establish high and stable production method in Japanese climate. Three treatments set at differences in fruit number per truss in which fruits were pruned to four, six or no-thinning.
  • Although there was not significant difference in the number of leaves and flowering trusses. leaf area of four fruit per truss was the largest, followed by others. The flowering rate and harvesting rate mainly depend on temperature but not on fruit load. The weight of leaf, stem and root decreased with increasing the number of fruit, especially reduction was higher in root was weight. Six fruits per truss produced the highest yield. The similar trend was observed in fruit dry weight. The average fruit weight of four fruits per truss was the biggest, followed by others. Fruit thinning had no effect on the Brix of the fruit.
  • The high correlation was observed between total plant weight and fruit weight. The similar relation was observed between vegetative part weight and fruit weight.
  • It can be concluded that the total plant weight was an important factor for high yield. Furthermore, six fruits per truss seem to be optimum number for high yield.

Keywords: tomato, limiting fruit load, year-round cultivation, dry matter production, plant factory


  • Original (Japanese)
  • Effect of Multi-Layered Thermal Curtain and Water Heat Storage on Heating Load of Pipe-Framed Greenhouse
  • Hiroki KAWASHIMA, Takao FURUICHI, Kiyoshi MIYAUCHI, Makio HAYASHI, Takenosuke NAOKI and Yuji NAGASAKI
  • The effect of a special multi-layered thermal curtain, referred to as the “Futon screen”, and water heat storage on the heating load of a pipe-framed greenhouse was investigated, through a comparison between two pipe-framed greenhouses; one was a greenhouse equipped with the multi-layered thermal curtain (M-house), and the other was a control greenhouse (C-house).
  • The internal temperature of C-house and M-house, both being without heating, were 2.4 ℃ and 7.1 ℃, respectively, when the outside temperature was 0 ℃. The heating load coefficient of M-house, 1.43 W∙m-2∙℃-1, was lower than that of C-house, 2.39 W∙m-2∙℃-1. Further, the consumption of heating oil and the heating load of M-house were both approximately 40 % lower than those of C-house. It was clear that the Futon screen reduced the heating load of the greenhouse by approximately 40 %.
  • With the introduction of the water heat storage, the heat loss coefficient of M-house did not change; however, the heating load coefficient of M-house reduced from 1.43 W∙m-2∙℃-1 to 0.91 W∙m-2∙℃-1. Further, the consumption of the heating oil in M-house with the water heat storage was reduced to 36 % that of C-house.

Keywords: pipe-framed greenhouse, thermal curtain, water heat storage, heat loss coefficient, heating load, energy saving


Vol.44 No.3 (September, 2013)

  • Original (Japanese)
  • Effect of MgCl 2 Addition on Struvite Precipitation and Ammonia Emission during the Early Stage of Composting
  • Takeki MAEDA, Masaki SAKUMA, Hiroaki KUDO, Takahiro TATEISHI, Mikinori TSUIKI, Fumihito MIYATAKE, Kazunori IWABUCHI and Kouki MAEDA
  • The effects of MgCl2 addition to composting material on struvite precipitation and ammonia emission were investigated. Beef cattle manure was used as the composting material and the 15-day composting process was carried out in a small-size reactor. When the rate of MgCl2 addition was increased, the pH of the initial material decreased and the electrical conductivity increased. In addition, the degradation rate of volatile matter decreased to 63 % of that without addition of MgCl2 when the addition rate was 0.4 mole per kg of initial dry manure (mol kgDM0-1). An increase in struvite nitrogen was observed after MgCl2 addition at 0.03 mol kgDM0-1 (MgCl2 addition: 0.1 mol kgDM0-1) ∼ 0.07 (MgCl2 addition: 0.4 mol kgDM0-1), and the utilization rate of Mg from additional MgCl2 for struvite precipitation was calculated to be 34 - 16 %. Ammonia emission after 0.4 mol kgDM0-1 MgCl2 addition decreased to 70 % of that without MgCl2 addition. These results suggest that, following the addition of MgCl2 to composting material pH reduction had a greater effect on the reduction of ammonia emission than did the increase in struvite precipitation.

Keywords: struvite, ammonium magnesium phosphate (MAP), chemical additives, ammonia emission, composting


  • Original (Japanese)
  • Internal Wind Pressure Coefficients for Designing Pipe-framed Greenhouses
  • Yasushi UEMATSU, Nam-Seok KIM, Hideki MORIYAMA and Sadanori SASE
  • The internal pressure coefficient of a pipe-framed greenhouse is numerically simulated by using the time history of external pressures measured at the locations of gaps existing in the walls of pipe-framed greenhouse in a turbulent boundary layer with a 1:40 scale model. The external pressures are also measured at two cross-sections providing the largest load effects on the structural frame and cladding. Focus is on the bending moment at the windward column base of a frame placed at about 1.0 H inside from the gable wall, with H being the model height, for discussing the design wind loads on structural frames. Based on the results, we proposed models of internal pressure coefficient and the peak internal pressure coefficient to be combined with those of the external pressure coefficient and the peak external pressure coefficient for designing the structural frames and cladding, respectively, which we had proposed in our previous studies. A good agreement of the load effects predicted by these models with those obtained from a time history analysis indicated that the proposed models of the external and internal pressure coefficients are reasonable.

Keywords: pipe-framed greenhouse, internal pressure coefficient, wind-tunnel experiment, numerical simulation, load effect


  • Original (Japanese)
  • COP Measurement of Air Source Heat Pump Installed in Greenhouse
  • Fumiyuki GOTO, Kazuhiro SHOJI, Hideyuki MANO and Masashi HANAGATA
  • Lately, the use of air source heat pumps in a greenhouse has attracted attention. COP (Coefficient of performance) is used as an indicator of the performance of the heat pump. Since the environmental condition regulated by JIS standards and that in a greenhouse to measure COP are very different, measurement of COP in the greenhouse has been requested. In this study, we measured COP using an air enthalpy method with the heat pump installed in a greenhouse. First, the air temperature and the wind speed of the heat pump outlet which influence the COP were measured. The wind speed at the left of the outlet was 2.7 m/sec faster than that at the center. In contrast, air temperature at the left was 2.5 ℃ lower than that at the center. Second, we developed a measuring device for COP which consisted of a duct, a hood air collector, a suction fan controlled with an inverter and a Pitot tube avoid variation of wind speed and temperature. The variation of the air temperature was reduced within 0.3 ℃ and the difference of air volume between the data provided by the manufacturer and the value obtained by the device was less than 5 %. Finally, the device was tested under the similar condition of JIS standards and in the greenhouse, demonstrating that the device is effective in measuring COP accurately.

Keywords: heat pump, COP, greenhouse, air enthalpy, heating


  • Note (Japanese)
  • Factual Investigation of Radioactive Cross-Contamination of Brown Rice from Rice Huskers
  • Takahiro NODA, Yasuyuki HIDAKA, Kenta SHIGEMATSU, Yosuke KUBOTA, Takashi YAMASHITA and Sumihiko MIYAHARA
  • In response to the Fukushima Dai-ichi nuclear disaster, radioactivity tests are being done on all brown rice grown in Fukushima Prefecture under the instruction of the Fukushima Prefectural government. Test results have shown that only a few bags of brown rice harvested in 2012 contained radioactive cesium which exceeds regulation levels (100 Bq/kg). As a result of these findings, both the Japanese Ministry of Agriculture, Forestry and Fisheries and the Fukushima Prefectural government suspected that the rice was not contaminated during growth but during processing by the rice huskers used in the prefecture.
  • To investigate the possibility of cross-contamination, we conducted a factual investigation by testing rice processed by rice huskers that were used in Fukushima Prefecture until the nuclear disaster. We measured the total radioactive cesium concentration (134Cs + 137Cs) in rice samples after processing by the rice huskers. We found the brown rice processed in earlier tests contained higher concentrations of radioactive cesium than the control brown rice which was grown in the same paddy as the samples processed by clean rice husker, and the concentration in the samples gradually decreased as the rice husking tests progressed.
  • After the tests were completed, we disassembled the rice huskers and cleaned each part. While cleaning, we collected residues in order to measure the total radioactive cesium concentration inside the huskers. We found the residues had cesium concentrations much higher than those of the brown rice in our test samples. Moreover, we found that the radioactive cesium concentration of the rice samples was proportional to the contamination ratio of the residue in the rice samples.
  • Our results revealed the risk of cross-contamination of brown rice when radioactive cesium residues are not cleaned from the inside of rice huskers. In order to effectively avoid radioactive cross-contamination, residues should be cleaned from rice huskers before use.

Keywords: radiation cesium, cross-contamination, rice, rice husker


Vol.44 No.4 (December, 2013)

  • Research Paper (Japanese)
  • An Oil Heater Requires a Greater Heating Load than a Heat-pump System Because of Increased Heat Loss into Soil
  • Shinsuke FURUNO, Kei SUGAWARA, Limi OKUSHIMA and Sadanori SASE
  • Because of the escalating price of fossil fuels, heat-pump systems for greenhouse heating have become widespread. Such systems are reported to be capable of decreasing energy costs, which have led to their widespread installation. However, a comparison of the heating load of a heat-pump system with that of a fossil-fuel-fired heater has not been reported so far.
  • In general, the hot air blower in a heat-pump system for greenhouse heating differs from that in a fossil-fuel-fired heater. Therefore, in this study, the heating load and heat loss on the soil surface of a heat-pump system, which releases hot air directly, was compared with that of a fossil-fuel-fired heater, which releases hot air using air ducts. The results can be summarized as follows:
  • 1) The heating load of the heat-pump system (Qgrn) was approximately 80 % that of the fossil-fuel-fired heater (Qoil).
  • 2) The observed heat loss on the soil surface of the greenhouse equipped with a heat-pump system (Hgrn-1) was less than that of the greenhouse equipped with a fossil-fuel-fired heater with ducts (Hoil-1).
  • 3) Differences between Qgrn and Qoil increased with an increase differences between Hgrn-1 and Hoil-1.

Keywords: fossil fuel fired heater, heat loss under soil, heat pump system, heating load, hot air ducts


  • Research Paper (Japanese)
  • Internal Wind Pressure Coefficients for Pipe-framed Greenhouses in a Side-by-Side Arrangement
  • Yasushi UEMATSU, Nam-Seok KIM, Hideki MORIYAMA and Sadanori SASE
  • The internal pressure induced in two or three pipe-framed greenhouses arranged in parallel are numerically simulated by using the time history of external pressures measured at the locations of gaps existing in the walls of pipe-framed greenhouse in a turbulent boundary layer with a 1:40 scale model. The distance between greenhouses is varied from 0.25 H to 1.0 H, with H being the ridge height. The results indicate that the internal pressure coefficient is affected by many factors; i.e., the location of greenhouse under consideration, distance between greenhouses and wind direction. In our previous papers, we first proposed models of the external pressure coefficient and the peak external pressure coefficient for designing the structural frames and cladding, respectively, based on the results for an isolated model. Then, we proposed models of the internal pressure coefficient and the peak internal pressure coefficient to be combined with those of the external pressure coefficients. The present paper discusses the application of these models to the plural greenhouses arranged in parallel.

Keywords: pipe-framed greenhouse, side-by-side arrangement, internal pressure coefficient, wind-tunnel experiment, numerical simulation


  • Technical Paper (Japanese)
  • Development of the Weather-Resistant Agricultural UV-blocking ETFE Film
  • Hiroshi ARUGA, Yasuyo NISHIMURA and Yasufumi FUKUMOTO
  • Development of the UV-blocking ETFE film (ETFE is a fluoropolymer) for greenhouses is examined, focusing on the production process sequence from synthesizing the filler, to treating the surface, forming the dispersive compounding, extruding the film and applying the anti-drip coating. The weathering resistance of the film is also discussed. The new UV-blocking filler (CeO2:SiO2=40:60), the treatment agent for dispersion, and the processing method that was devised for the ETFE resin were developed.
  • This UV-blocking film is transparent and after 12 years, the deterioration in UV-blocking function was less than 4 % and its mechanical property remained almost unchanged.
  • That success is attributable to the technology used in synthesizing silica-coated cerium dioxide in the solution layer for transparency, performing the silica-coating process in the solution layer for weathering resistance, and developing the dispersion technique so that the filler can be dispersed uniformly in the ETFE resin.

Keywords: ETFE, UV blocking, weathering resistance, greenhouse covering film, filler


  • Technical Report (Japanese)
  • Reduction Effects of the Radioactive Cross-Contamination in a Husker by Washing with Rough Rice
  • Yasuyuki HIDAKA, Takahiro NODA, Kenta SHIGEMATSU, Yosuke KUBOTA, Takashi YAMASHITA, Sumihiko MIYAHARA and Nami YOKOTA
  • In order to reduce the radioactive cross contamination in a husker, we investigated the “decomposition cleaning of a husker” and the “washing with rough rice” technique. Washing the husker with rough rice involves supplying 40 kg of rough rice, carrying out circulation inside the husker for about 3 minutes, and discharging.
  • Although investigation showed that the caesium concentration in the brown rice was reduced through decomposition cleaning, the reduction effect was dependent on the early contamination grade. It was shown that decomposition cleaning was not a perfect method for preventing cross-contamination because one example of brown rice was found that failed to meet the food safety standards (100 Bq/Kg).
  • The examination of the “washing husker with rough rice” technique showed that the caesium concentration of brown rice was reduced to 1/10 from the early stages of husking. This result was not influenced by the initial contamination of the husker, and the resulting caesium concentration of the brown rice was below the regulation value. For this reason, we concluded that washing a husker with rough rice is an easy and positive method for preventing radioactive cross contamination. However, since the caesium concentration in the residue inside the husker is high, for cross contamination recurrence to be prevented it is necessary to remove the residue inside the husker.

Keywords: washing with rough rice, decomposition cleaning, caesium radiation, cross-contamination, husker, radioactive decontamination