To improve the performance of alcohol engine, concrete methods for materializing pulverization and vapourization of fuels and their effects were studied experimentally. The results are as follows.
(i) The method of changing thickness of heating plate, in which whole exhaust gas passes through heating chamber, is suitable for fine adjustment of heating quantity, and the method of changing passing quantity of exhaust gas through heating chamber, in which the thickness of heating plate is kept constant, is suitable for rough adjustment.
(ii)In the method of partial passage of exhaust gas, the characteristics of nozzle are varied not only by its size, but also by its position whether it is located in front or rear of heating chamber. The characteristcs of the former are apt to be influenced by throttle valve opening, and the latter by engine speed.
(iii) By adjusting the combination of heating quantity and ignition timing optimum to get the maximum output, it is turned out that ignition timings for ethanol should be advanced by 6.8° and 4.8° respectively, compared with the ones for gasoline which is and is not pulverized and vapourized.
(iv) Using the same engine under the same operating conditions, such as throttle valve opening, engine speed, and weight of inhaled air at theoretical air-fuel ratio, tests were executed using ethanol and gasoline, which were and were not pulverized-vapourized, and adjusting the combination of heating quantity and ignition timing optimum for the maximum output.
The results are as follows.
(a) By the pulverization-vapourization method, output and thermal efficiency are increased both in ethanol and gasoline, and the toxic compounds in exhaust gas, especially NOx, are decreased.
(b) Without pulverization-vapourization, ethanol is not superior to gasoline, but by pulverization-vapourization method, ethanol becomes to be superior to gasoline in both engine performance and cleanliness of exhaust gas.
(c) As the fuel consumption and evaporation heat of ethanol are far higher than gasoline or kerosene, it will be effective to control heating quantity and ignition timing in accordance with throttle valve opening and engine speed.

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For the purpose of evaluating basic design features an air-and charge-cooled Wankel rotary engine of about 10 PS {7.5kW} for general use, two prototype single rotor engines displacing 67cc (RX 67) and 93cc (RX 93) per revolution were tested in which. side-port intake and peripheral-port exhaust system similar to that in the Fichtel & Sachs KM37 engine is adopted.
This report deals with (1) the performance chracteristics at full throttle of the two prototype engines and (2) the decrease in volumetric efficiency which restricts the specific power output of these engines. The results obtained are as follows.
(1) The principal performances of the two engines are shown in Tables 1 and 2 and Fig. 1.
There is little engine vibration except slow rotation of the engine due to gyroaction. In addition, they have excellent durability.
(2) It is evident that these features show significant advantages over conventional reciprocating engines. Admitting its high manufacturing cost by about 10%, it possesses enough desirable qualities for small size air-cooled engine for general use.
(3) The ratios of the width of rotor housing b to the eccentricity e are 3.75 for RX67L and 5.25 for RX93L, respectively, The RX93L engine designed with the larger value of b/e than the RX67L engine has an advantage over the latter in the specific power output by about 6%. The size of b, however, cannot be determined arbitrally without considering the strength of eccentric shaft, allowable bearing pressures, etc.
(4) Air-cooled Wankel rotary engines can be classified in two types: (a) low speed type, equipped with a governor for using in principle at rated speed such as 5, 000rpm and has higher torque characteristics in the low speed range, and (b) high speed type, commonly is not equipped with the governor and designed to produce higher power output in the high speed range over 5, 000rpm. The standard design values of the maximum break mean effective pressure for these engines are: (a) Pme_max=4.15kgf/cm²{407kPa} for the low speed type, but Pme_max=4.4kgf/cm²[432kPa] may be used if a little deterioration in combustion characteristics at light load is allowable, and (b) Pme_max=4.9kgf/cm²{481kPa} for the high speed type.
(5) When the running conditions of the air-cooled Wankel rotary engine are changed from motoring state to firing state, the temperature of the induction mixture rises rapidly by about 80°C. Consequently, volumetric efficiency is inevitably reduced by 20-25% and the specific power output decreases. The main reason is the leakage of high temperature combustion gases through sealing devices and the temperature rise of the induction mixture by cooling the rotor. The most difficult problem in the Wankel rotary engine is the sealing of combustion chamber against leakage without excessive friction and wear.

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The method and the conclusions of this investigation were as follows:
1. The soil-annulus system was defined as: |π_J=f_J(π₂, π₃, …, π₈)(j=1, 9, 10)…|π_J′, π₈′| in which π₁=S/ρV², π₁′=F/ρV², π₂=h/b, π₃=b/d, π₄=λ/d, π₅=ρVd/μ, π₆=d/D, π₇=σ/ρV², π₈=c/ρV², π₈′=a/ρV², π₉=z/λ, and π₁₀=J/λ and the nomenculature |π_J′, π₈′| means both π_J′ and π₂′ are exchangeable with π₁ and π₂. And S is soil-shearing stress, F external frictional stress, c cohesion, a adhesion, ρ bulk density of soil, μ coefficient of viscosity of soil, D diameter of soil particle, d mean diameter of annulus, b section width of annulus, h grouser height, λ grouser span, σ normal stress, V frictional speed, Z annulus sinkage, and J horizontal displacement.
2. Under the condition of in situ test, we found that the system was a distorted model in which π₅ and π₆ were distorted by length scale. Therefore, some scale effect was inevitable when the π₅ or π₆ was valid.
3. Then, prediction equations were expressed as: π_JP=δ_J·π_Jm…|π_JP′, δ_J′, π_jm′| in which p expresses prototype, m model, and δ_J prediction factor.
The behaviours of δ_J, were investigated by experiment, utilizing scaled annuli and High-Speed Annular Shear Device KS-2. The device is designed to be able to control shear speed and normal stress, and to which annuli of different sizes are able to be attached.
4. In the soil-shear test at maximum shear failure, no scale effect was observed for the different types of soils from dry sand to soft clay and for the length scale change from unit to about 1.7.
5. The soil shear strain as expressed by π₁₀ at maximum shear failure increased with the increase of the scale. This was most remarkable in dry sand, followed by sandy loam and soft clay in order.
The reason was considered that the system distortion reached maximum for dry sand, because dry sand is a plastic body, whereas strain is a quantity valid for elastic body.
6. In soil-steel (annulus) external friction test, the frictional stress increased remarkably in proportion to the annulus size for dry sand, while the trend became weak for sandy loam, and no scale effect was observed for soft clay.
7. When the system distortion was interpreted as soil particle size becomes smaller relatively, i. e. frictional plane becomes smooth with the increase of annulus size, the test results were coincided qualitatively with existing test result and friction theory which claim that external frictional stress increases with the increase of the smoothness of the frictional plane.

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Hydraulic vibratory tillage test device was designed and constructed. Experimental analysis on soil failure, soil resistance and required power was carried out using this test device as well as the soil bin with the controlled soil conditions. The following results were obtained.
1) The soil in vibratory tillage failed almost in the same manner as in non-vibratory tillage; the average shearing pitch of the soil remained almost unchanged, Therefore the mode of vibration gave no significant effects on soil failure pattern, and the sail pattern was characterized by the properties of soils.
2) The optimum vibration frequency was the twice the shearing frequency of the soil when the velocity ratio was constant. Under this vibratory condition the movement of the blade matched with the shearing of the soil, and the shearing pitch became constant, which resulted in the minimum resistance and power.
3) As for the direction, the horizontal vibratory tillage attained minimum draft when the above optimum vibratory conditions were given.

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This paper reports a study of draft reduction a sub-soiler which introduces water dissolved air (Photo 1) under pressure in order to break down soil, based on the previously reported experiment in the draft reduction of the sub-soiler which introduces pure water. Since water dissolved air causes air bubbles which plug flow in the soil-bed layer and a high resistance pressure is produced among soil particles; the resulting draft reduction of the sub-soiler increases by the large breakdown power. A device which produces water dissolved air continuously (Fig. 2) was made and the draft of the sub-soiler was tested introducing continuously this water dissolved air from the top under pressure into the soil-bed layer In this paper, the solvent in which the air is dissolved is water but in the future we are planning to replace the water with liquid fertilizers in slurry form, and it will be introduced into pasture fields where the soil-bed layer around plant roots is compacted and hard. This provides plants with fertilizer and aerates plants and makes the soil soft. The results of this experiment are as follows;
1. The rate of air which can be dissolved into water in a high pressure tank, is shown in Fig. 3. The ratio of oxygen and nitrogen discharged when water dissolved air is released in the atmosphere is about 1:2 and therefore the concentration of oxygen becomes higher than that of general air at a rated 1:3.8.
2. When the temperature of water is less than 15°C, the dissolving of air into water requires much time and when the temperature of water becomes high, the whole rate of dissolved air decreases as shown Fig. 3. Consequently the optimal temperature of water is around 15-20°C.
3. The resistance pressure produced when water or water dissolved air flowed in one direction (in one dimensional flow) into the soil in a soil cell shown in Photo 2, was shown in Fig. 4. The resistance produced pressure of the flow of water dissolved air became higher than that of water flow in proportion to the increase in flow rate and was 1.5 times as large as that of water flow at about 10gf/s. cm² in flow rate.
4. When water dissolved air was forced under pressure into the soil-bed layer at the fixed condition of the sub-soiler in an acryle resin soil-bin prior to the traction test in the field, a cavity was formed around the nozzle port as shown in Photo 3.
5. In this case, the produced pressure at the nozzle port was changed vs. time as shown in Fig. 5 and the resulting waves recorded on a oscillograph at flow of water dissolved air showed a more severe jigzag change than the water flow.
6. Comparing the draft reduction of sub-soiler when water dissolved air was introduced with that of the water flow, a sufficient rate of draft reduction was observed in case of the former even under a condition where no draft reduction was observed in case of the water flow as shown in Fig. 7.
7. The rate of draft reduction is shown collectively in Fig. 9 vs. the flow rate, including the traction velocity and primary draft. The flow rate of 15cm³/cm per unit traction distance was required at a minimum for draft reduction when water was introduced, on the other hand, when water dissolved air was introduced, a sufficient draft reduction was obtained in 6cm³/cm in flow rate at minimum per unit traction distance.
8. The profits and expenditures of energy of this method are shown in Fig. 10. When the traction speed of the sub-soiler was slower than 6.0cm/s, the energy required for producing water dissolved air was more than the energy reduced by the draft reduction and therefore no merit of energy reduction was evident. But when the traction speed became about 25cm/s and the flow rate of 310cm³/s was introduced, a large amount of draft reduction was observed and energy was reduced by 30%.
The writer wishes to express his gratitude to the Hokkaido University Computing Center for allowing h

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Profiles of a grassland in Hokkaido Univ. were measured by the apparatus which was applied the slope integration method and were evaluated. Some conclusions were as follows.
1. Like other rough terrains, no periodic components were observed in profiles of grassland.
2. Judging from power spectral densities, the roughness of the south-north profiles was almost the same as that of the east-west profiles. And the roughness of the grassland was in the range from ‘very poor’ to ‘poor’ of the recommended classification by ISO/TC 108.
3. Very little relationship was found between each profile by calculating the frequency response function.
4. The conclusions obtained from the above results are that the rough ground like the examined grassland can be recognized as a set of independent profiles.

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An accurate metering system consisted of a bowl type feeder and a metering cell was investigated. The following results were obtained.
1. Metering tests indicated that the value of seeding speed Vp were obtained from the following conditions when a seed cell fill was above 99%; for soybean, Vp was 1.0m/sec at centrifugal effects Kv of 1.49, for corn, Vp was 0.9m/sec at Kv of 0.93, and for peanut, Vp was 0.4m/sec at Kv of 1.76. The metering system metered seeds with fewer errors than seed plate of hopper type metered seeds.
2. When seeds were continuously conveyed on the truck, the input time interval t required for a seed to arrive at a input port on the truck was represented by normal distribution, and the statistical conditions between t and the metering time U for a output port on the metering device to meter a single seed was as follow;
t-5σ<U(U<t+5σ)
t+5σ≤U

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Rolling of the walking type rice transplanter was theoretically investigated. The results are as follows.
1) Dynamic model of the rice transplanter was determined as shown in Figs. 1 and 4. The differential equation of motion in regard to the rolling can be deduced from kinetic energy, potential energy and dissipation function of the system by substituting into Lagrange's equation. The equation of motion (15) can be expressed by the damped three-degrees-of-freedom system and becomes nonlinear by the decrease of mass and the change of moment of inertia and of the location of center of gravity as the time proceeds. Therefore, numerical calculation was done by digital computer.
2) All kinds of coefficients necessary for the numerical solution of the equation of motion were measure and parameters were determined, the values being shown in Tables to 4. The moment of inertia of mat type seedling was calculated from the theoretical equation (21).
3) The solution curve in the center of gravity of the body is shown in Fig. 7. From the results, it can be estimated that the body will rise up by 9 to 12mm when the seedlings are exhausted.
4) The displacement of the attaching point of planting finger can be obtained from the equations (15) and (21), the results being shown in Fig. 8. At the beginning of transplanting, the difference of the amplitude of right and left fingers was 2.7 to 4.4mm. At the end of transplanting, it reduced to 0.3 to 2.1mm. The displacement at the middle of right and left fingers was about equal to the rise of the body.
5) The results of the calculation of the rolling and the displacement of the float are shown in Figs. 9 and 10. The amplitudes decreased as the time proceeds, and the values were small in comparison with the vertical displacement of the body.

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The shearing characteristics of rice seedling mats for the Japanese type rice transplanter became clear as fundamental physical properties like the tension and compression characteristics. Conclusions were as follows.
(1) The shearing stress-displacement curves of mats were similar to those of soils with low density. These curves might belong to the strain hardening pattern.
(2) The relationship between normal stresses and shearing strengths of mats was approximated by the Coulomb's equation as same as soils.
(3) In the characteristics indices for shearing strength obtained from tested mats, the values of cohesion (c) ranged from 0.05 to 1.29kgf/cm² (5 to 126kPa) and those of angle of friction (φ) ranged from 25° to 44°.
(4) In consequence of the analysis of effecting factors in the strength and stiffness characteristics, it became clear that a main factor was physical properties of bed soil. The planting density of seed and the weight of roots influenced on the cohesion (c) and the volumetric deformation modules (K). An influence of the weight of roots on the cohesion (c) seemed remarkable in the low compression stress region.
(5) Those shearing characteristics were tried to explain with behaviours of a simple model of mats.

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Experiments were carried out to know the magnitude of gyroscopic couple which occurs on piano-wire cutting blade during mowing work. The influence of gyroscopic couple on the physical stress of operator and ease of operation was also studied and compared with cut-away blade. The results are as follows:
1. The gyroscopic couple of piano-wire blade was approximately 1/5 and 1/20 of the 4 and 8 cut-away blades, respectively. The scattering of grasses mown by the piano-wire blade resulted in a fewer turn-over motions and smaller moment of inertia of the blade.
2. Owing to the above reasons, the use of piano-wire blade reduced the time required for mowing and the physical stress of operator.
3. Man-machine system which had a mechanical part consisting of a tapered ridge model were used for tracking task, and the performance of work was analysed dynamically. The human operator's adaptability to the change of differential constant T₁ was experimentally investigated for preview tracking system, in which assumed transfer function was included. It is known that the differential constant T₁ is dependent on the physical stress. Under the signal of tapered shape, differential constants T₁ for piano-wire blade, 4 and 8 cut-away blades were 0.38, 0.43, and 0.90, respectively. The result gives good agreement with the magnitude of gyroscopic couple and the physical reaction of operator.
4. In mowing work with 8 cut-away blade, a large quantity of gyroscopic couple of 1.5kg-m or thereabout was occurred in stepping of feet and in turn-over motion of blade for brushing aside grasses. This value is equivalent to 3kg of force at handle grip.
5. In the tracking work using cut-away blade, the large phase shift and the large displacement (the distance between the cutting blade and ridge models) appeared even in low ground speed because of larger gyroscopic couple, resulting in difficult handling.
6. Judging from surface EMG, heart rate and rate of work, the most appropriate cutting width is considered to be 150-200cm.

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The proper conditions for the practical treatment were investigated with many experimental results which had been shown in our previous report as to the pig and cattle waste.
1. The value of lnk′ was obtained, when the parameter n of eq. (1) was fixed on n′. Regression line of k′ formed a line for a series of experimental conditions, So lnk′ was regarded as an index of the characteristics of compressive dehydration.
2. Moisture content of the sample after a practical short operation was obtained from eq. (1) by using the value of n′ and lnk′, The proper conditions were studied by obtaining the moiture contents after 5 and 30 seconds,
3. The authors obtained the following results as the practical characteristics for the compressive dehydration of animal waste.
a) The moisture content after 5 seconds of operation showed a large drop, but the one after 30 secods had almost the same value as after 5 seconds.
b) Dehydration in the case of Pre-coat condition and thin layer condition decreased the moisture so low as the waste's being available for a compost.
c) The effect of the pressure increase on the cattle waste was larger than the effect on the pig waste. When the pressure was more than 9kgf/cm², the effect of the dehydration was large for the thin layer condition.
d) The effect of the compression velocity on the dehydration was hardly recognized.
4. Dry matter contents of the effluent were around 0.2g/cm³ for the pig waste except for the pre-coat condition (Fig. 10 and 11). The mean value of all condition was 0.04g/cm³ for the cattle waste (Fig. 12 and 13).

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Pattern classification is the most suitable technique for the multipurpose sorting system of fruits and vegetables. A simple computerized sorter was developed with the pattern classfication technique.
Accuracy of the computerized pattern classification sorting was compared with that of manual sorting. Results were as follows.
1. A computerized pattern classification system was easily assembled with a micro computer and its peripherals. Processing time of this system was relatively slow, but the system had a good performance to develop the softwares.
2. Length and width were usefully available for sorting Sayaingen, but there were few Sagainges both lengh and width of which fell in the same standerized class.
3. This patten classification system could measure the length, width and area in good accuracy with some modification.

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In order to establish the quality assurance system of fruits by means of sampling inspection theory, factors affecting sugar content (Brix) of Kaki (Dyospyros Kaki L cv. Fuyu) were analized by Hayasi's quantification scaling type 1, and then, the sampling inspection plans were designed. The results were as follows:
1. The factors that had a remarkable influence on the sugar content were tree and producer in order of degree. Therefore, the sampling unit was expected to be stratified by these factors.
2. Every population variance of the sugar contents of fruits on a tree, a producer or producers was estimated respectively as following:
That was, in the early season, 1.241, 1.459, 2.224; in the best season, 0.805, 1.205, 2.915; in the late season, 0.885, 1.798, 3.471.
3. It was considered that the distribution of sugar contents of fruits on a tree was approximately the normal distribution by plotting on the normal probability paper. That resulted the distribution within trees or producers in the normality nearly if the fruits were sampled from a random tree. So, it would be of good that Single sampling inspection or Sepuential sampling inspection was applied.
4. If the sampling lot was made of fruits from a tree in the best season, the quality assurance was able to do as follows:
When the sample size was five and the lower acceptance value was 16.23 by means of Single sampling inspection, it was able to assure the buyer that the mixing percentage of fruits 14.0 and below (fraction defective) was 0.1% and below with the probability of 90%. That was equivalent to assuring of the mean value of the lot 16.77 and over.
If Sequential sampling inspection was adopted, the same assurance as Single sampling inspection was able to do when the lower acceptance value 17.86 at one sample, 17.05 at two, 16.77 at three and so forth.

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The rheological properties of cooked cocoons were investigated for the purpose of obtaining the fundamental knowledge for measuring the state of cooked cocoons.
The results obtained are summarized as follows:
1. The properties of cooked cocoons were represented by rheological models composed of springs and dashpots (Fig 5).
2. For under-cooked cocoons, the dashpot C₂ in the 4-element model was infinite, that is, the model was equivalent to 3-element model. For further cooked cocoons, either 3 or 4-element model was alternatively used, and finaly for well-cooked cocoas, 4-element model appropriately represented their rheological behavior.
3. The better performance of reeling operation was obtained for cocoons represented by the 4-element model.
The cooking state of cocoons for optimum reeling operation could be recognized by alteration of the viscoelastic coefficient, C₂ in the 4-element model

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