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Volume 50, Issue 2
Displaying 1-15 of 15 articles from this issue
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S. ISHIBASHI1988 Volume 50 Issue 2 Pages 1-2
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (1959K) -
Effect of Stiffness and Lugs of Rear TireKazuhiko OHMIYA1988 Volume 50 Issue 2 Pages 3-10
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSTo evaluate the characteristics of the rotational vibration of tractors (pitch, roll, yaw), high-lugged tires and turf tires were selected and the effect of lugs of rear tires on the rotational vibrations was investigated. The inflation pressure of the rear tire was controlled so that the static stiffness of the rear tire could be varied, and the effect of the static stiffness on the rotational vibration was also investigated. The results showed that the high-lugged tire behaved like a polygon and the vibrations activated by lugs of rear tires were especially found in the roll motion. It appears that the rotational vibration levels were usually decreased as the static stiffness of rear tire was decreased.View full abstractDownload PDF (2812K) -
Nobutaka ITO, Masayoshi NAKATA, Takayuki ISOGAI1988 Volume 50 Issue 2 Pages 11-18
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe ratio of the length to the width of the crawler is one of the most important factors in considering the turnability and the steerability of the tracked vehicle.
In this paper the various model crawlers consisting of the different shape ratio of the length to the width with the same contact area were used to find out the effect of the shape of crawler on the turnability. The dynamic behavior of the moment of the turning motion resistance and the crawler sinkage were observed.View full abstractDownload PDF (897K) -
Hiroshi KONDO, Katsumori SATO, Noboru SUGIYAMA1988 Volume 50 Issue 2 Pages 19-25
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn this study, a new formula for predicting the turning resistance which excludes the assumption on the instantaneous steering center is proposed. To validata the accuracy of the formula, a series of labolatory experiments was conducted by employing a model vehicle and a simplified model which pick up traveling gear of the vehicle.
It was shown that the calculated results by the proposed formula agreed in good accuracy with experimental results, and the formula can be utilized for the computation of the required horsepowers in the design of the traveling gear devices of vehicle.View full abstractDownload PDF (789K) -
Characteristics of Outer Electric Field System and Property of Charged Particle Deposit for Electrostatic Pesticide ApplicationKohnosuke TSUGA, Hideyuki ICHIKI, Michio KAJIYAMA1988 Volume 50 Issue 2 Pages 27-35
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSEquipment and characteristics of electrostatic application with electric field by high voltage wire for three different types of formulations, were presented in the previous report.
In this report, applications of smoking pesticide and liquid formulation by non-heating fog machine were carried out. And characteristics of electric field by high voltage wire, such as various kinds of electric plastic insulated wires and layout of wire within or without pseudo-plant, were evaluated. It was shown that drift application methods of charged chemicals with high voltage plastic insulated wires nearby the crop row and in the crop canopy were available for the improvement of chemicals deposit.View full abstractDownload PDF (1106K) -
Takaharu KAMEOKA1988 Volume 50 Issue 2 Pages 37-45
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDesorption equilibrium moisture content were determined by using the method of salt solutions (static method), for rough rice, brown rice and hull at 20, 30 and 40°C and at eight different relative humidities in the range of 11.3% to 85%. The short grain rough rice (cv. NIPPONBARE) used in this study was harvested at an average kernel moisture content of 30% d. b.. About 10g of rough rice, brown rice and about 3g of hull were put into glass patty dishes and then these sample holders were put in the same humidity control chamber. The weight change was measured each day using an electric balance until the change in weight reached 1mg/day. The moisture content of the samples at this stage was defined to be the equilibrium moisture content.
The Dubinin-Astakhov (D-A) equation which was derived based on Polanyi's potential theory was used to smooth the equilibrium moisture content data. The most suitable parameters of D-A equation were obtained for rough rice, brown rice and rice hull at 20, 30 and 40°C. These D-A equations were used to analyse the equilibrium moisture content data of rough rice, brown rice and hull. Using the data smoothed by this epuation, the equilibrium moisture content difference among rough rice, brown rice and hull was examined.View full abstractDownload PDF (1152K) -
Estimation of an Error in Stress Calculation and Calculated Stresses under Various ConditionsShinkichi YAMAGUCHI, Shingo YAMAZAWA, Kaichiro WAKABAYASHI, Masahiro T ...1988 Volume 50 Issue 2 Pages 47-54
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSTo calculate drying stresses in a brown rice kernel by applying the numerical method proposed in the previous papers, the time required for drying and the dimensionless radial coordinate of the kernel have to be divided into a number of increments, Δt and ΔR, respectively. In the present paper, the calculations of drying stresses in a brown rice kernel were carried out using various increments, Δt and ΔR, at a given drying condition to estimate an error in calculation. As a result, it could be found that the fitting values of Δt and ΔR were 0.04 hours and 0.05, respectively, to perform the stress calculation in a rice kernel without noticeable error.
More calculations were carried out using the above values of Δt and ΔR under other drying conditions. Based on the calculated results, changes of cracked rice percentage with drying conditions were discussed by considering that the crack generation in a brown rice kernel depended primarily on the drying drying stresses. It was pointed out that the changes of the cracked rice percentage were highly dependent on the equilibrium moisture content which related with temperature and humidity of the drying air.View full abstractDownload PDF (1158K) -
Satoshi MURATA, Akio TAGAWA, Sadato ISHIBASHI1988 Volume 50 Issue 2 Pages 55-64
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSMoisture movement and heat transfer in grain bed during storage were measured and analyzed by the method of diffusion theory of porous hygroscopic solid in two cases as follows:
1) Initial moisture gradient in iso-thermal condition: The equilibrium vapor pressure between vapor of the void space and moisture of the grain in the bed was assumed, and the non-linear movement equation of vapor in the void space was derived from the diffusion equation with the adsorption isothermal equation of the grain.
The calculated results of the equation by finite-difference method agreed well with the measured result.
2) Initial thermal gradient in initial even moisture contents: the calculated results from approximate analytical solutions of heat conduction and the diffusion equations with linearized adsorption isothermal equations agreed well with the measured results in early period.
From above results, it was shown that the moisture movement in grain during storage might be estimated by these Equilibrium-Diffusion theory.View full abstractDownload PDF (1403K) -
Mathematical Model of Tea DryingHitoshi YOSHITOMI1988 Volume 50 Issue 2 Pages 65-73
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSTwo mathematical models which can be applied to both constant rate period and falling rate period of tea drying were proposed. The one is the one dimensional moisture transfer model (plate model) which was applied to the simulation of static drying. The peculiar drying characteristic curve of tea leaves was well explained by this model under the assumption that the coefficient of moisture diffusion varied with moisture content. The other is the lumped model (two tanks model) which was a simpler model and was applied to the simulation of both static drying and primary drying process. The result showed that the squeezing effect of kinetic action in the primary drying process was very large. As the simulation result agreed with the experimental result, it is considered that this model was valid for tea drying analysis.View full abstractDownload PDF (1048K) -
Application of finite element inverse analysisHaruhiko MURASE1988 Volume 50 Issue 2 Pages 75-83
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe complexity of agricultural products in their shape and material stracture often causes difficulties in measurements of parameters of their mechanical properties. The direct application of measuring methods used for non biological materials is not always effective to agricultural products and would give unreliable data even on the simplest parameters known as the elastic moduli. Taking physiological characteristics of living cells as kell as anisotropy and inhomogeneity into consideration is necessary for studying physical properties of a plant material. The water potential of plant tissue relates the physiological state of living tissue of plant to the mechanical behavior of cellular materials.
In this study, it is assumed that a plant material is homogeneous and isotropic at cellular level. The consideration of mechanical behavior of plant materials is based on this assumption. The overall objective of this work is to develop a total instrumentation and software system capable of estimating parameters of physical properties of a plant material.
In this paper, the finite element inverse analysis that plays a key role in this software system is discussed. The finite element software developed is used to calculate the elastic moduli and the water potential effective coefficient from deformation of the cellular material.View full abstractDownload PDF (950K) -
Hitting Characteristics of WatermelonTsuneo KAWAMURA, Isao NISHIMURA1988 Volume 50 Issue 2 Pages 85-92
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA purpose of this study is to measure the maturity or the internal quality of watermelon by a non-destructive method. The hitting experimental equipment is developed and the characteristics of vibration and sound of watermelon are measured. An experimental sample is suspended by a simple pendulum as not to disturb the vibration of sample by hitting. The experiments were done in this fashion.
In part 1 of this study, the wave forms of vibration and sound obtained by hitting on the side or the bottom of watermelon were recorded. The characteristics of vibration and sound and the fundamental physical properties of watermelon are recorded.
In part 2, the relationship between the values of physical properties and the results of sensory evaluation will be reported.
In part 3, the method judging the maturity or the internal quality of watermelon will be reported by some values of physical properties and the analyzed results of the data of vibration and sound.View full abstractDownload PDF (971K) -
Takayoshi AKINAGA, Yoshihiro KOHDA1988 Volume 50 Issue 2 Pages 93-99
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSKidney beans, sweet corns and okras are exported from Okinawa to mainland Japan in winter and spring. They produce high vital heat under normal temperature conditions in these seasons. Therefore, they may rapidly diteriorate without cooling. They are commonly transported by aircrafts without temperature management. Because precooling facilities are not sufficiently developed in Okinawa.
Most airfreight container has poor ventilation characteristic due to its water proof constructions, and are not suitable for fresh agricultural products.
Ventilation and insulation characteristics of existing container were investigated. The ventilation container for fresh vegetables, fruits and cut flowers were developed as a trial and its performance were proved.View full abstractDownload PDF (4346K) -
Automatic Testing System for Hydraulic PerformanceKunio NISHIZAKI, Yasuro SUGIURA, Yoshiji OCHIAI1988 Volume 50 Issue 2 Pages 101-107
Published: 1988
Released on J-STAGE: April 30, 2010
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On the drying capacity, the economic evaluation and the advantages and disadvantages of 3 types of solar drying systemsKenji NAKAGAWA, Kazuo HORIBE, Sei-ichi OSHITA1988 Volume 50 Issue 2 Pages 109-114
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (793K) -
Setsuo HAYASHI1988 Volume 50 Issue 2 Pages 115-119
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (598K)
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