As can be seen from the recent trend of weight reduction of existing tractors, it seems necessary to consider the optimal configulation of tractor frame. To develop an approximate method to estimate the fatigue strength, several experiments and analyses were performed taking the rear wheel axis housing for direct research material. The following comments pertain to the specific results in this research.
1) A computer program was successfully developed for solving frequency distribution of actual stress with the peak count method by offline data processing units.
2) Since frequency distribution patterns differ according to the number of sampling data, it would be discerned that around 1500 data are enough to maintain constant distribution pattern.
3) In each test condition, e. g. plowing, rotary tillage and maneuver, frequency distributions are tend to follow Weibull's distribution.
4) Throughont experiments, shape parameter m can be seen within the restricted range, below 1.0. Actual stress which takes place during operation might be characterized to exhibit the excessive stress with higher probability.
5) Using Miner's linear damage law, the life of the rear wheel axis housing was investigated under the assumptions of introducing actual stress. The effect of the number of repeated stress was evident and consequently basic data for the body styling of tractor were obtained.
6) The degree of fatigue seems to be affected considerably depending upon the slope porions of dimensionless S-N diagram or time intensity.

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We investigated the performances of the first transmission belts of small powered tractors and tested the relation between belt life and belt velocity, initial tention, pulley diameter, twisted angle and air temperature. The experimental results were compared by multiple regression analysis. The results were as follows:
1. The first transmission belts of small powered tractors, which farmers used in fields, were damaged after 90-120 hours.
2. Manufacture's specifications for the tensile strength of belt, which showed a large degree of statistical fluctuations in our study, were usually higher than the tested values.
3. The angle of belt twist had a significant effect on belt life, but factors such as velocity, pulley diameter and load had little effect.

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The edge-curve of a rotary blade is one of the most important design factors. This is influential to the entwining phenomenon of grass and straw on it and also to tillage resistance characteristics, and othrs.
The authors introduce a new approach to the design theories of effective edge-curves as follows;
1. Considering the slip-out motion of the grass and straw on the edge-curve, the possibilities of ideal edge-curves to remove and push them into the soil were discussed.
2. Grass removing characteristics of the rotary blade are mainly determined by the value of “edge-curve angle” α between radius direction and the tangential line of the edge-curve.
3. The design theories are composed so as to meet the authors' experimental results for Asian paddy rice field condition as follows:
The edge-curve angle smaller than about 55 to 57.5° is apt to have entwining phenomenon of grass and straw on the tip portion of the blade.
The edge-curve angle smaller than about 65 to 67.5° is apt to have also entwining phenomenon on the neck (holding) portion of the blade.
4. The grass removing performance of the rotary blade will be achieved by the edge-curve with its angle α, linearly increasing from the tip toward the neck portion. The equation of edgecurve design is proposed in polar coordinate as follows;
r=r₀sin^1/kα₀sin^-1/k(α₀+kθ)
where, r₀ is the radius of the tip point of the edge-curve when θ is zero degree, α₀ is the edge-curve angle at the same starting point and k is the constant being selected by a designer who decides the increasing ratio of the edgecurve angle α from the tip toward the neck portion of the blade. The recommended value of α₀ is 55 to 57.5° when r₀ is 300 to 200mm and about 1/18 for k (that is, increases the edge-curve angle about by 10° in accordance with the increase of θ by 180°).
5. Some examples of the rotary blade having the theoretical edge-curve are shown.

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The digital sampled data adaptive control system with the logical operation of the combine was investigated. In this control system 3 inputs of the engine load, the feed rate and its fluctuation were sensed, and the traveling speed of the combine was controlled. The setting value of the feed rate was automatically adjusted to adapt to the change of the grain conditions.
The feed rate was detected as the straw layer thickness on the lower conveyor of the combine by a differential transformer. The engine load was detected by a tachometer generator as the threshing cylinder rotating speed. Sampling and holding was done by RST flip-flop after transforning two input signals into on-off signals.
The fluctuation of the feed rate was detected by comparing the present feed rate with that of 4.5 seconds before (the time required for the crop detected by the differential transformer to reach the threshing chamber).
The increase of the traveling speed of the combine was done in case that the load in the threshing chamber was expected to decrease orr the engine output had surplus. Decreasing of it was done in reverse condition.
The setting value of the feed rate was lowered by giving lower speed than R2 judging from the logic that the setting value was too high, if both signals of the feed rate were lower than its lower limit (LL) though the engine was overloaded (in FIG. 1), It was in reverse if both signals of the feed rate were higher than its upper limit (LH) even though the engine speed was over upper limit (RH),
With Boolean algebra these logics were calculated and simplified to construct electronic circuit.
The field experiment of this adaptive control system using g P. S. small combine with hydrostatic drive showed better results than the conventional control system.

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This report describs about the systematic design procedure and predictions of shaft torque and mechanical efficiency in power sprayer.
The plunger diameter is the foundamental size in design process of power sprayer. In systematic design process, the plunger diameter was enlarged or reduced using the scale factor obtained as ratio of displacement volume of power sprayer,
The plunger diameters were calculated from practical displacement volume for four power sprayers, and compared with the practical sizes of supplied models. They agreed approximately.
In the models designed by systematic design, the performance predictions using the calculating equations of torque, were practised. Furthemore, the test on four power sprayers was conducted, and the both results were compared with each other.
As the displacement volumes were changed, the torques were changed by the scale foctors L, L^2/3, and L^4/5, respectively and they were shown Fig. 2.
The predicted results of performance were approximately the same as experimental results.
The shaft torques and mechanical effciency were calculated for those models which were designed by systematic design in the range of scale factor L=1.0-2.82 and discharge pressure P=0-25kg/cm², were shown in Fig, 5 and 6.
The usefulness of systematic design and performance prediction in power sprayer were recognized.

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On the basis of the previously reported experiment in the measurment of the drag and lift coefficient of ellipsoidal seed particles, it is reported in this paper that the uniform distribution of the particles with different air drag-coefficients was wade by setting the duct with four nozzles on the spinner of the centrifugal distributor and making the particles with a large air drag-coefficient enlarge their flight distance by means of injecting air flow along the flight direction of particles.
1. The particles launched out show complicated flight trajectories affected by the air drag, the gravity and the lift. Although they are launched out under the same condition, yet their fallen location is distributed in a certain range of area depending upon difference of their flying orientation in the air.
2. The mean distance of flight and the diameter of distribution varies under the influence of the species of particle, the initial launching velocity and the initial velocity of injected air. This is shown in Fig. 4, 5 and 6.
3. When the pasture seed particles, red and ladino clovers, timothy and orchard grasses, are evenly scattered at one time, their mean distance of flight must be almost the same. When the clovers are emitted at the inital velocity of 10m/s and timothy and orchard at 10m/s to 50m/s (the emitted initial velocity in case of light particles gives little influence) in the initial velocity of 20-30m/s of injected air, the above result will be achieved and their meam distance of flight is about 4.0m.
4. However, as for the seed particles are almost similar in shape and nearly even in drage coefficient, yet extremely different in weight—for example orchard grass and osts—it is impossible to make them emit at the same distance, whatever emitting velocity and injected air velocity may be given to them.
5. Launched out particicles are scattered in the shape of lateral oval at the small injected air velocity, and in the shape of longitudinal ovel in the flight direction of particles at the great injected air velocity.
6. The particles fed at a point on the spinner are descended at the mean distance of flight with the highest probability. Their coefficient of distribution density is shown as i=i_maxe^-kr2. This is an approximate estimation.
7. The coefficient of the maximum distribution density is determind by the distribution area of particle, regardless the kind of species. It is shown in the following experical formula; i_max=9.42/D_x·D_z-0.106
8. With regard to unknown particles, their mean distance of flight and diameters of distribution can be estimated in reference to Fig. 4 to Fig. 6 using their known weight and shape as in Table 1. Their density of distribution can be determind by means of the formula 28 and 29. Moreover, the actual result of the density of distribution while driving on the field can be obtained by the intergration of area on diagram as shown in Fig. 14.On the basis of the previously reported experiment in the measurment of the drag and lift coefficient of ellipsoidal seed particles, it is reported in this paper that the uniform distribution of the particles with different air drag-coefficients was wade by setting the duct with four nozzles on the spinner of the centrifugal distributor and making the particles with a large air drag-coefficient enlarge their flight distance by means of injecting air flow along the flight direction of particles.
1. The particles launched out show complicated flight trajectories affected by the air drag, the gravity and the lift. Although they are launched out under the same condition, yet their fallen location is distributed in a certain range of area depending upon difference of their flying orientation in the air

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The factors which affect the intensity of delayed light emission (DLE) of tomato were investigated for the purpose of developing an automatic sorting mechanics, and the following results were obtained;
1. The relation between dark period and DLE intensity was investigated (Fig. 2). General working conditions, based on this result, were established as
Dark period for dark recovery of DLE; above 10 minutes, Decay period; above 0.7 seconds.
2. DLE intensity of tomato was saturated by the excitation of 5500lx for 3 to 6 seconds having the dark period of 10 minutes (Fig. 3).
3. Exciting illuminance needed for the DLE saturation of tomato increased inversely with the decrease of decay period. For the decay period of 1 second the illuminance for the saturation was 2750lx (Fig. 4).
4. The DLE intensity was directly proportional to the excitation area on tomato (Fig. 5).
5. Maximum DLE intensity of tomato was obtained at the flesh temperature of 13 to 17°C (Fig. 6)
6. The relation between the chlorophyll content and the DLE intensity was almost linear (Fig. 7).
7. Color sorting accuracy of tomato was investigated by means of DLE (Table. 2). The green tomatoes were sorted with high accuracy whereas that of the red tomatoes did not follow.
Separation of green tomato from breaker is of much importance from the point of practical application (breaker has a small white or pink star at the blossom end and may be ripened several days later).
8. The relation between the thickness of tomato flesh and the DLE intensity was investigated. Green ripe tomato emitted high delayed light from the flesh of 6mm thick, which was the same level with that of a whole or a half tomato. In case of red ripe tomato which contained a little amount of chlorophyll, a trace of DLE was observed which was not supposed to be influential on sorting accuracy (Fig. 8).
9. The DLE spectrum of intact tomato had a peak at the wavelength of 695nm and a bulge on the longer side, and agreed well with the fluorescence spectrum of chlorophyll.
Photomultiplier having a high sensitivity around the wavelength of 695nm is recommended as a DLE detector.

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To study the controlling factors which affect the drying rate during freeze-drying process, the authors have constructed an experimental freeze-drying apparatus as shown in Fig, 1. The characteristics of the apparatus as well as the experimental results obtaind from beef samples are summarized as follows.
1. The changes in sample weight, drying rate, temperature distribution in the sample, heater and platen temperatures and total pressure during the freeze-drying process of beef sample were measured and shown in Fig. 8.
2. The weight measuring device, shown in Fig. 2, had the sensibility of 0.37g and an accuracy of 1/250 when the sample weight was 68.0g.
3. The surface and the bottom temperatures of the beef sample were controlled within (-35-98) ±0.4°C, (-35-85)±0.5°C, respectively.
4. During sublimation dehydration process, the sublimation front showed a minimum temperature and its values were lower in the center portion of the sample than the values near the surfaces (See Fig. 8).
5. The average moisture content of dry beef specimen, which was determined by Karl Fischer method, was 3.4% w. b. (See Table 3).

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1) The formulae were derived for the estimation of the air flow rate of aeration and ventilation to control both the maximum temperature of the storage products and the gas concentration of carbon dioxide in the aeration system containing the products in storage room equipped with ventilator.
2) The Gore's equation on the temperture rise and the respiration rate of the fruits was extended that not only added the effect of the moisture content but also adapted to the cereal grains.
3) The respiration properties of rough rice was measured, and the six respiration coefficients, which chracterized the extended equation and was necessary for the practical use of the formulae, were obtained by the least squre method from both the measured data and the published data of several farm products.
4) An example was showed for design calculation.

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