In order to discuss the problems of continuous operation with small diesel engine for farm using rape-seed oil as fuel, the engine was operated for 50 hours at 2000rpm under the 3/4 load of its rated horse power. The results obtained were as follows.
1. The performances under continuous operation were showed the similar tendency to the results of operation at rated horse power following the JIS method.
2. After 50 hours continuous operation, the characteristics of lubricating oil such as specific gravity, kinematic (s) viscosity, surface tension, carbon residue and neutralization number were almost equal to those of using light oil.
3. A small amount of carbon deposit was observed in combustion chamber of the tested engine and its quantity was as small as that of using light oil.
4. The density of the black smoke of exhaust-gas was less than that of using light oil.

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This paper describes what properties the discontinuum model (II) which is reported previously indicates under its small deformation. It is very difficult to analyze the properties of the particle system with general arrangement of particles, so this paper discusses the properties of normal particle systems with simple and regular arrangement. Consequently, it was proved that the discontinuum model (II) was able to have isotropic visco-elasticity which was considered as a fundamental dynamic property of deformable body in small deformation. At the same time, the concrete method was given for the analysis of defordable body under small deformation.

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A criterion of farm tractor performances is the ratio of travel reduction or slippage of the driving wheels for a given drawbar load. The conventional method of measuring drive wheel slippage is cumbersome and time consuming. The reason for the difficulty of finding an appropriate method for measuring instantaneous slippage of the driving wheels of tractors may be that we can not measure travel velocity or speed as a function of time.
The purpose of the present experiment was to develop a system of direct measurement of tractor wheel slippage using a gage wheel which measures travel speed of a test tractor on a packed and relatively smooth ground surface.
The results of the tests were as follows:
1) The gage wheel apparatus was suspended by a spring damper in such a way that the preload could be changed. The travel speed was measured by a pulse generator (600P/R) which was coupled to and driven by the gage wheel shaft. As the base value for computing the amount of wheel slippage the engine speed was measured by another pulse generator (60P/R) which was attached to the PTO shaft of the tractor. After two signals were converted to DC voltage proportional to each speed, they were lead to an analogue circuit to compute the amount of wheel slippage.
2) The performance of the gage wheel apparatus as a travel speedmeter gave a measurement accuracy of±1.0%, which was applicable to velocities ranging from 0.4 to 3.0m/s on a packed and relatively smooth ground surface.
3) The cut-off frequency of the low-pass filter used to average the data was determined using the travel reduction v. s. drawbar pull curve. The appropriate cut-off frequency may be considered to be 0.1 or 0.2Hz.
4) To investigate the practical application of this system a drawbar pull test was conducted by using a test tractor with 52 PS engine power on a concrete and a clay soil test track. The drawbar load was adjusted by the brake of the tractor for loading in such a way to produce drive wheel slippage ranging from 0 to 100% continuously. The non-slippage travel speeds were set at 0.45, 0.89, 1.35 and 1.66m/s.
5) The maximum drawbar pull on the concrete test track was developed before the drive wheel slippage reached 100%. It was further found that the amount of slippage with respect to the nonslippage travel speed decreased from 75.5 to 55.0% as the ground speed increased. On the contrary, the maxiumum drawbar pull increased by about 30% as the slippage speed increased. But the relation between the slippage speed and the maximum value of the drawbar pull showed opposite tendency.
6) On the clay soil test track, the maximum drawbar pull and the drawbar pull at 20% wheel slippage showed the same tendency as described in 5). No relation between the drawbar pull and the 100% wheel slippage was found in these tests.

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Although the design theory on the rotary blades arrangement has been studied for many years, the most design of the C-shaped blades arrangement is still based on a designer's experience. This might be caused because the necessary conditions for the blade arrangement are not clarified and simplified, and the design process is not well established. Therefore, the authors studied the design theory on the C-shaped blades arrangement theoretically and empirically. The results are as follows:
1) It should be considered for the design of the rotary blades arrangement to keep static and dynamic balance of the rotary axle, to minimize the forced vibrations of the rotary axle disturbed by the tillage resistance, to make the soil slices as uniformly as possible, to level the tilled soil and to make the production of the rotary axle easy.
2) The consideration of the horizontal and vertical components of the tillage resistance on a rotary blade can be omitted by regarding that the curves of the components are similar to a curve of a torque on a blade.
3) It is estimated that the fluctuation of the unbalance moments M_x(θ), M_y(θ) which are around the axes in the forward and upward direction, is approximately as same as the distribution of the dynamic unbalance moment in the circumferential direction. This means that if the dynamic balance is well maintained, there is no need to consider M_x(θ) and M_y(θ).
4) The disign process of the rotary blade arrangement was described using the design flow-chart. The performances of the rotary axles which were designed based on the process were mostly satisfactory.
5) The estimation of the torque curve of a rotary axle is an important process for rotary blades arrangement. The estimation method is fundamentally based on a model torque curve of a blade, which is determined experimentally as a quadrilateral in Fig. 6. The characterizing factors of the model are determined by Equation (24). All the torque curves, which are drawn with the phase differences of the peaks equivalent to those of their blade holders, summed up to a overall torque curve. The estimated torque curves showed good approximation to the measured ones from the practical view point.

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As a fundamental study on the separating mechanism of the digger, the count-rates of potato, clod and stone which were formed into known thickness, were measured at the stationary condition using Gamma-attenuation detection apparatus with ¹³⁷C_s.
1. By using equivalent thickness of iron plate to that of potato, clod and stone, the linear calibration lines which indicated the possible range of separation were obtained (Fig. 7).
2. The possible range of separation which was obtained from the linear calibration lines almost coincided with the experimental results by the trial electric circuit for separating device with ON-OFF mechanism.

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Effective factors on the vertical force for pulling (pulling force), which is equivalent to the maximum available frictional resistance for pulling root vegetables, were investigated.
For measurements of the pulling sorce, a precise force gauge was developed (Fig. 1), From the results of measurements, some rules for the effects of the characteristics of root vegetables and the conditions of soils on the pulling force were clarified (Fig. 2, Table 1, 2, 4).
The pulling force (F) was closely related to the surface area of main roots in soil (S), and the relation between F and S was given approximatly by a linear formula F=aS+b.
The coefficient a=(dF/dS) in this formula was determined by the kind of root vegetables and the condition of soils. This coefficient a was varied from 0.015 to 0.038 (with correspond to those factors) in this experiment (Fig. 3, 4).
The effects of the number of lateral roots and the size of small root on the pulling force were negligible (Fig. 5, 6).

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In order to harvest fruits effectively by shaking the trunk or the limb of a fruit tree, we must learn the vibration characteristics of the limb. And it is necessary to make a fundamental experiment by using the model of limbs. Therefore, the authors investigated the dimensions of limbs as the basic data for the characteristics. The main results are as follows:
(1) The size of a tree or a limb is expressed by the following formula.
K=100D²H, k=d²l
Where, K: scale index of tree (cm³)
D: diameter at the base of trunk (cm)
H: hight of tree (m)
k: scale index of limb (cm³)
d: diameter at the base of limb (cm)
l: length of limb (cm)
(2) The weight of the limbs with leaves was determined by using the indirect method (a) and (b). The relations between the weight and the scale index of limbs are shown in Fig. 11, 13 and 14.
(3) The relation between the weight percentages of leaves, fruits and woody part and the scale index of limbs is shown in Fig. 18.
(4) The center (leader) of a limb is regarded as a cone.
(5) The center of the gravity of a limb including leaves and fruits is at about 30% limb length from its base.
(6) As the diameter of limbs increases, the Young's modules becomes slightly larger.

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In-transit mechanical injury of fruits and vegetables was thought to be a fatigue failure due to the accumulation of damage caused by vibrating force during the transportation. For the purpose of estimating the in-transit injury of the products, S-N curve which was available for the fatigue analysis of metalic materials was used to determine the degree of damage or injury under the sinusoidal and random in-transit vibration. Degree of damage, D, was expressed as follows:
(a) Under the sinusoidal in-transit vibration, D=1/β∑_in_iG_i^α
(b) Under the random in-transit vibration,
D=f₀T/β(√2σ)^αΓ(1+α/2)
2. The magnitude of vibrating acceleration was determined in connection with the simulation time based on the analytical acceleration in the actual transportation. The magnitude of vibrating acceleration, G or G′, was expressed as follows: (a) When the same simulation time is used as for the actual transportation time, (i) When the occuring frequency of vibrating acceleration during the actual transportation was known at every acceleration level,
G=(∑_in_iG_i^α/∑_in_i)^1/α
(ii) When RMS value and expected frequency f₀ of random vibrating acceleration during the actual transportation were known,
G=√2σΓ(1+α/2)^1/α
(b) When simulated transportation time T is shorter than that of actual transportation T₀,
G′=G(T₀/T)^1/α
3. Judging from power spectrum density of vibrating acceleration, the components of vibrating frequency were grouped into the following three classes of 2-5Hz, 10-14Hz and 20-24Hz. The former two components could be observed at every speed of vehicle and the components of 2-3Hz and 20-40Hz were increased with the speed was gathered.
4. The relationship between the mean magnitude of vibrating acceleration G, and the speed of vehicle V, was obtained as G=0.028V^0.3
5. These analysis were applied to determine the factors of simulated transportation test for lettuce from Nagano to Tokyo and from Miyazaki to Osaka. The values of α and β in S-N curve were considered to be 4.17 and 5320 respectively from the previous work.

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The Hydraulic Locomotive described in this paper is a new means of transportation which uses a new power transmission method. The purpose of this study is to investigate the principle of the driving mechanism. The author introduced theoretical equations and compared theoretical results with those of the static experimental model. 1) To estimate the static pressure of the air-stream in an elastic pipe, the theoretical equation (31) was obtained. There are many approximations in the process of the complex calculation and the results were unsatisfied to conform with the experimental value. (Fig. 7)
From the fluid-movement equation, the theoretical formula (36) which indicates the horizontal force against the driven wheel was obtained. This equation is a simple formula and in conform to the experimental results. (Fig. 6)
From the above-mentioned investigations, it has become clear that the driving force of a carrier is expressed as a function of the initial static pressure P₀ and the air velocity V₀.

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In line with our previous efforts in developing a new filament-end-picking machine, the 3rd trial machine was constructed which was a revised and improved form of the 2nd trial machine to meet the actual operating condition. Results of the test obtained so far revealed that the machine showed much better performance than that of the conventional machine. It was also shown that the machine could be incorporated easily in present running filature factories to replace with the conventional ones.

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Beating treatment of rice straw chopped at the length of 2 to 5cm and removal of rignin by changing straw's chemical state with the use of soda are important process for waferability, and also digestibility to the ruminent animal. Rice straw was beaten with beater built as a trial, and treated with soda (sodium hydroxide, sodium sulfide). The following results were obtained.
1. The beating efficiency was about 2.1ps per 15kg/hr being feed at the beater speed of 1200rpm.
2. The beating efficiency varied with shear plate angle, beater speed, feed speed, row number of knives, feed quantity and clearance between shear plate and knives. From the result of analysis of variance, it was clarified that the cutting of straw in transverse direction decreased at the beater speed of 800rpm.
3. There was no large difference between unbeaten chopped straw and beaten one in the nutrients.
4. By spraying 5 to 15% concentrated sodium hydroxide with the rate of 10 to 30% to the natural dry weight of chopped straw, the fibers were loosed, and the wafer strength increased. This process showed the effect of alkali treatment. With regard to beating treatment, the beaten straw treated with similar concentrated alkali showed the multiple effect with mechanical (beating) treatment.
5. Sulphidity was indicated as the effect of the coexistence of sodium sulfide and sodium hydroxide. Sulphidity of 0% had high solvent power. As the effect of beater, fiber length was decreased rapidly.
6. The levels of factors showing good effects upon the wafer strengths and digestibilities were sulphidity of 50%, beating number (Bn)=1, and additives of flour. The order of wafer density (=ρ) value due to additives or binders was as follows: flour≥molasses>brewer's grains>citrus pulpy>rice bran. The ρ value was 1.06g/cm³ for flour added and 0.61g/cm³ for rice bran.
7. When chopped straw was treated with sodium hydroxide, beating treatment improved digestibility significantly. These treatments were necessary to obtain digestibility of 70%. The additive of 2 to 10% by weight of flour, molasses, brewer's grains and citrus pulp increased digestibility up to 60 to 65%.

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When tomato flow is disturbed at tomato packing center, it causes damages on tomatoes and machine troubles. Also, it makes troubles on the management at the center when tomato counter does not work normally.
Therefore, in order to dissolve these troubles, a trouble detector at tomato counter, using integrated circuit (IC) or micro-computer, was designed and examined.
As the sensor, two micro-switches A, B with distance H were installed as shown at Fig. 1, and four pulses (A, B, frequency divided pulse C and delay pulse D) were selected to detect the abnormal pulse combination (Fig. 4).
Truth table of the four pulses is shown at Table 2, and normal logical equation was shown as N=BC(A+AD)+ACD
Logical equation of tomato flow stagnation was simplified as Z=CD.
Judging of any trouble in detail is possible, but it is reasonable from the point of cost performance to display the information of the three states that are normal (N), tomato flow abnormal (Z) and other abnormal (S).
Logical circuit of tomato flow abnormal signal Z using IC was designed as shown in Fig. 5, and was examined to be successful.
Next, the trouble detector using microcomputer (SDK-80) was tested. Program lists for stagnation detector and for switch trouble detector are shown in Table 3 and 4.
The memory of these programs for about one hundred detecting cases will need approximately 1100bytes.
The cost performance of this detector is better than a detector using IC since as the scale of plant becomes larger.

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The noise caused by hot air heater in the vinyl greenhouse is a matter of increasing concern. To reduce the noise from the heater, a sound proof wall was designed. It consisted of the perforated wooden plate, air layer and sound absorption materials (urethane foam and chaffs).
As a result, the noise could be reduced about 7-9dB(A) in greenhouse, and the noise around the greenhouse became under 50dB(A) at the distance of 15-20m from the greenhouse.
It also became clear that the chaffs could be use as effective sound absorption materials.

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This paper discusses the general control equation of plant community (7), introduced in previous paper (I), under the following conditions; (i) age is neglected (ii) plant community is constructed by one plant species (iii) community is not controlled, but (iv) withering is taken into consideration. In order to study the related problems of plant withering, its mechanism should be given.
In this paper, two models dealing with death phenomenally are introduced. The one, called model III, is based on the idea that withering increases proportionally as the community grow over a certain volume level, and the other, model IV, is the one which is based on the hypothetical death function. Model III is the one based on the following assumption; there is a limit level YLIM that is smaller than maximum community level Y*. The weeker plant in the community dies to maintain the level YLIM, as the community is growing up. This model may be able to describe static characteristics of community, such as mean weight of plant species. However it will not be appropriate to express naturally dynamic one such as distribution change.
Model V is a model based on the death function (6). It is more natural than model III to represent dynamic characteristics such as changes to limit level YLIM and distribution changes. The death function is however, assumed hypothetically and it may be difficult to obtain the actual value.
With regard to the conservation law, which means that community can not grow over a certain volume level in a unit area of field, model III may be ecologically more appropriate.

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Different approach on commodity production systems was made by Meadow in 1970 in which he developed a simulation model based on System dynamics.
The apparently successful application of system dynamics to the hog cycle phenomenon prompted the author to investigate problem in control theory terms, since system dynamics is essentially an offshoot of control theory.
In this paper a continuous time model based on classical control theory is considered to the hog cycle system. The model as presented here does not take into consideration of seasonal variation of production and so, as it stands, applies only to those commodities which are laigely unaffected by the season and whose production is governed mainly by price.
The following were mainly discussed on the model presented here.
1) Hog cycle as a limit cycle oscillation, including the observation of transient and frequency response to the price fluctuation due to the demand.
2) Stabilization of the system.
3) Applications to other commodities.

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