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Volume 42 (1980 - 198･･･
- Issue 4 Pages 475-
- Issue 3 Pages 327-
- Issue 2 Pages 197-
- Issue 1 Pages 7-
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Volume 42, Issue 1
Displaying 1-22 of 22 articles from this issue
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Mitsuo IIMOTO, Masaki MATSUO1980 Volume 42 Issue 1 Pages 7-14
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to discuss the combustion of rape-seed oil in combustion chamber, this paper dealed with polytropic change, temperature of combustion chamber and rate of heat release. The maximum combustion pressure and the amount of piston-rings abrasion were also measured.
The obtained results were as follows:
1. Index number of polytropic change using rape-seed oil under rated horsepower operation at compression stroke was equal to 1.33, and for the light oil it was equal to 1.33.
2. The changes of temperature in combustion chamber obtained from indicator diagram. The combustion temperature using rape-seed oil at 50 to 80% of cylinder volume under expansion stroke was lower than that of light oil and therefore the exhaust temperature using rape-seed oil was lower than light oil.
3. From the calculation of the rate of heat release, the combustion of rape-seed oil was superior to light oil.
4. In the analysis of variance of the maximum combustion pressure, the variation of the peak value using rape-seed oil was smaller than that of light oil.
5. The amount of piston-rings abrasion using rape-seed oil (as fuel) was smaller in quantity than that of using light oil.View full abstractDownload PDF (1044K) -
Theoretical Analysis by a Slip-Line MethodKoichi HASHIGUCHI, Koichi IWASAKI1980 Volume 42 Issue 1 Pages 15-20
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSBy use the slip-line method, the authors have been studying to estimate the bearing capacity of farm soils or the indentation resistance of rigid punches to various machine elements. In these problems the width of material was not usually wide enough to be regarded as a semi infinite body. In the previous paper, the bearing capacity of the infinite body in the shape of truncated wedge subjected to a single strip load was elucidated.
In this paper, bearing capacity of quarter to semi infinite bodies against a strip load was analyzed. The assumed slip-line field is shown in Fig. 2. As shown in this figure, this field is composed of a rigid region just under the load, two logarithmic spiral slip-line regions and two similar straight slip-line regions.
The geometrical configuration of this field is prescribed by four parameters and the relation ship of these parameters is expressed by the following equation.
ω={1-4/cosφ(cos2ξ+tanφsin2ξ)sin(μ-φ+ξ)cos(μ-φ)exp(ξtanφ)}-1 (1)
where ω is a ratio of a half of load-width to a distance from the center of load to the side-edge of material, φ is a half of spreading angle of the infinite body, ξ is a spreading angle of the logarithmic spiral slip-line region and φ is the angle of internal friction. Especially denoting the value of ω at ξ=π/2 as ωp, this value is given by
ωp={1+4/cosφcas2(μ-φ)exp(π/2tanξ)}-1 (2)
The bearing capacity is given as follows:
In case of φ=0,
q=1+2ξ-cos2ξ. (3)
In case of φ>0,
q=cotφ{1-sinφcos2ξ/1-sinφexp(2ξtanφ)-1} (4)
where q is a non-dimensional bearing capacity (bearing capacity/cohesion), The value of ξ in these equations can be calculated by substituting the values of ω, φ and φ to the geometrical equation (1).
The calculated results of q are shown in Fig. 5 (a)-(d) for φ=0°, 30°, 45°, 60°, and φ=0°, 15°, 30°, 45°. As shown in these figures, the calculated results show the following trends.
1. The larger φ, the larger is the rate of the increment of the bearing capacity to that of φ.
2. For ω≤ωp the bearing capacity is constant, and ω>ωp it decreases first abruptly and then decreases gradually with the increment of ω. The larger φ and the smaller φ, the stronger becomes this trend.
3. The larger φ, the larger becomes the rate of the increment of the bearing capacity to that of φ.View full abstractDownload PDF (694K) -
Tests of Two Wheel Tractor on Flat LandSeiji NAKAO, Hajime TANABE1980 Volume 42 Issue 1 Pages 21-28
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSContinued from the first of this study, in this paper, the applicability of the empirical equations was discussed on the basis of experimental results in flat land, using the two wheel tractor equipped with agricultural tire and steel-lugged wheel (attached with the non-skidding plates) respectively.
Main results were as follows:
(1) On the rolling and driving wheel of agricultural tire, the experimental value of C agreed well with the estimated value by using the maximum frictional resistance at the side slip angle of under 10 degree and the sliding frictional resistance at side slip angle of over 10 degree in the empirical equations.
(2) The experimental values on the steel-lugged wheel were the same results as the values on agricultural tire. The reason for this was that there was found no effect of the non-skidding plates of wheel owing to the soil fixed on the plates.View full abstractDownload PDF (1207K) -
Tatsuya BANNO, Syotaro MORISHIMA1980 Volume 42 Issue 1 Pages 29-36
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to clarify the behavior of tractor on the slope, the running loci on the slope were studied For the tractor running on the slope, the difference of the driving force between wheels on both side of axle can be found depending on the running resistance of wheel on the basis of the weight difference of wheel axis between wheels on both side of axle, consequently it leads to the
speed difference of wheels on both side of axle. Therefore, the turning center is formed on the turning center is formed on the valley side due to the speed difference, and the tractor turns downward. Therefore, the running locus when the actual steering angle δ is zero, namely in case of no steering, it is expressed by the following equation.
x=-FD2/2μWhsinθ∫tt0√1-sin2θsin2tdt
t=π/2-φ
y=FD2/2μWhsinθ(√1-u02-√1-u2-ln1+√1-u02/u0+ln1+√1-u2/u)
u=sinθcosφ
In order to make the tractor run on a contour line, it is necessary to give the actual steering angle δ in which the turning center is formed on the mountain side of the tractor so that the speed difference between wheels on both side of axle is eliminated. The running locus in case of such a steering is expressed by the following equation.
x=∫φφ0FD2cosφdφ/2μWhsinφcosφ/√1-sin2θcos2φ-FD2/1cotδ
y=∫φφ0FD2sinφdφ/2μWhsinφcosφ/√1-sin2θcos2φ-FD2/1cotδ
Model test and actual vehicle test were carried out. For the actual vehicle test, a 14 PS tractor was used, and the running locus in case of no steering was investigated on a pastured slope. For the scale model test, the one-fifth model was used, and the running loci in case of steering or no steering were investigated when the model runs on a veneer board covered with vellum paper. Giving the same conditions as the experiment to the theoretical egtation, and using μ=0, 012, the theoretical running locus was determined. It was found that it almost agreed with the experimental running locus.View full abstractDownload PDF (1146K) -
Thrust of the Single CleatMinoru KOMATSU1980 Volume 42 Issue 1 Pages 37-42
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSI measured and examined the thrust of single cleat to get a constructed data of crawler unit. This unit is used for harvesting of Baker's garlic, by that intended to improve tractive performances of walking tractors on sand dune fields with demountable crawler unit.
1. Having fixed cleat width (b) and cleat length (l) in considering the planting conditions, the grouser height (h), grouser angle (θ) and contact pressure (p), which are another comparatively alterable variables on the cleat factors are examined.
2. Test conditions of these variables used in this study were as follows: grouser height is 3, 6, 9 and 12cm; grouser angle is 45, 60, 75 and 90°; contact pressure is 0.10, 0 15, 0 20, 0.25 and 0.30kg/cm2.
3. For thrusting, effect of these three variables and of interaction p and h is significant at the 1 percent level. Especially, contact pressure was 72 percent as factorial contribution and grouser height was 26 percent. From the above test, it was proved that these two variables have a great influence on thrust.
4. The increase of contact pressure and grouser height makes proportional increase of thrust. Specific thrust, which almost shows a certain value independent of grouser height, varied with the conditions of contact pressure.
5. For grouser angle, thrust reached its maximum value when the angle acting perpendiculerly against the surface of field, was 90.
6. The rate causing thrust by grouser was larger when contact pressure was low, and its maximum value under the condition of the experiment was 52 percent.
7. Still fixing cleat width and soil wet density (γ), an experimental equation which predicts thrust (Ft) together with variables can be written as follow:
Ft=0.315 γ0.254 b 2.056 p 0.746 h 0.198 θ 0.280=38.573 p0.746 h 0.198 θ 0.280
8. Providing various soil wet density (γ) from 1.3 to 1.6g/cm3, it was proved significant for thrust. So showed the change of thrust influenced by soil wet density as ratio of thrust variance, to predict thrust against varied soil wet density in different fields.View full abstractDownload PDF (802K) -
Haruo EZAKI, Masami UENO, Syotaro YUZAWA, Akira YODA, Michikazu ICHIKA ...1980 Volume 42 Issue 1 Pages 43-49
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe deflection of rice seedling mats was studied as a measure of physical properties of them. In this study a part of physical properties, deflection properties, of rice seedling mats could be grasped by the use of a creep test subjected to dead load and a continuous loading test subjected to concentrated load at the center of the span. The kinds of bed soil, the planting rate and the days for raising of seedling were considered as experimental factors and changed to several levels to vary qualities of rice seedling mats provided for tests.
1) The two types of deflection test, one of them was simply supported at the opposite ends of a mat with the dead load and the others were built in at the opposite ends of a mat with the concentrated load at the center, were treated as easy methods to estimate the mechanical strength of rice seedling mats by the comparison with the deflection at the center of a certain span. It seems that the latter test gives an accurate estimation to the mechanical strength.
2) The deflection of rice seedling mats have little change in the measuring duration (within three minutes) either above-mentioned method (cf. Fig. 2).
3) The deflection of rice seedling mats was plastic, as shown in. Fig. 4 and 7.
4) The deflection of rice seedling mats was influenced by the conditions for raising of seedling, the kinds of bed soil, the planting rate, the days for raising of seedling, the weight of roots, the water content of mat and so on.View full abstractDownload PDF (1027K) -
Theoretical Analysis of Four Bar Linkage Transplanting MechanismShigeo UMEDA, Nobuo HONAMI, Vinh Duc CHAU1980 Volume 42 Issue 1 Pages 51-56
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis paper presents the fundamental dynamic characteristics of rice transplanting mechanism consisting of the four bar linkage. The numerical analysis was done using the motion equations of the four bar linkage by assuming that the angular velocity of crank-shaft was constant.
The main results were obtained as follows:
1) The torque fluctuation of crank-shaft and the forces acting on the fixed link were mainly caused by the motion of coupler, because the mass and the moment of inertia of it were greatest as compared with the others.
2) The patterns of torque fluctuation showed two peaks per rotation of crank-shaft, while the variations of vertical and horizontal component of exciting forces were similar to the sine curve with the phase difference 90 degrees each other.
However, according to the experimental results, the gear backlash, the cam acting on the pusher to insert the seedling into the soil, etc. were significant factors which gives the influence on the dynamic characteristics of rice transplanting mechanism, besides the inertia forces of links.View full abstractDownload PDF (725K) -
Process of the Development of the Suitable Grain Bag for Automatic Sacking DeviceMasato SUZUKI, Haruo EZAKI, Sasakazu IMAZONO, Takao SUGIYAMA, Masao MA ...1980 Volume 42 Issue 1 Pages 57-62
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe suitable grain bag as the automatic sacking device for combine harvester was developed. This bag has a inner flap inside of itself as shown in Fig. 3, which looks like a cylindrical and bottomless small bag.
To determine the size of inner flap, many kinds of grain bags were made and tested.
As a result, when the ratio of width to length of inner flap was more than 0 6, sacked grain was not overflowed.
On the other hand, it was necessary for the grain bag to be sacked during the sacking operation so as to increase the quantity of grain sacked. In order to find out the condition of vibration from a practical point of view, the laboratory tests were conducted under various combination of the conditions such as amplitude, frequency of oscillating pan and so on.
According to the test results, the optimum conditions to increase the quantity of sacked grain were as follows: the distance between hanger of bag and oscillating pan should be shorter (10cm) than the length of bag, frequency be about 300cpm, amplitude be 30mm, and oscillating time be more than 30 seconds.View full abstractDownload PDF (6113K) -
Model Experiments on the Harvesting Mechanics with Parallel PlatesTadashi FURUYA1980 Volume 42 Issue 1 Pages 63-67
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs a root vegetable harvester for taking the roots from soil block around them, a primary model consisted of a pair of rectangular plates arranged in parallel situation was developed. The efficiency of the model was tested by using root vegetable in an artificial field.
From the result of experiments it was recognized that the penetrating depth of plates increased with the increase of the distance of two plates. The relation between the distance of plates (1) and the penetrating depth of plates (g) was expressed approximately in a following function,
logg=k11+k2.
The constant k1 in this formula was determined by the soil conditions. This formula suggest that harvesting root is possible under the condition
logg≥k11+k2.View full abstractDownload PDF (2118K) -
Physical Properties of Sugar Cane StalksHiromi IZUMI, Takayoshi AKINAGA, Yoshihiro KOHDA1980 Volume 42 Issue 1 Pages 69-74
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSSugar cane machinery manufacturers and suger cane processing factories are in need of physical properties information on sugar cane to improve the efficiency of their work. In order to contribute to this purpose, the physical properties of suger cane including dimensions, strength and Young's modulus were measured for the variety NCo 376.
The following results were obtained:
1) The moisture contents decrease with maturation especially at the top portion of stalk. High correlation was observed betwen sugar contents and moisture contents of stalk, and the coefficient of correlation was -0.94.
2) A significant correlation was also observed between penetrating resistance and moisture contents of sugar cane stalk especially at the portion in which the moisture contents decreased with maturity.
3) Young's modulus of sugar cane stalks at the base portion obtained by compression test was 419kg/cm2 with rind, 291kg/cm2 without rind and 90kg/cm2 without rind loaded normally to stalk axis.
4) Young's modulus of sugar cane stalks measured by bending test was 3.31×103kg/cm2 for the upper portion, 2.25×103kg/cm2 for the middle portion and 2.20×103kg/cm2 for the base portion.
5) Poisson's ratio of the base portion of suger cane stalk was 0.344 with rind and 0.467 without rind.View full abstractDownload PDF (948K) -
Trial and Determination of SpecificationToshitake ARAMAKI, Takemi ABE, Jun YAMASHITA1980 Volume 42 Issue 1 Pages 75-83
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSExperiments were carried out to determine the construction specification of trial flail type pianowire blade.
The results of experiments were summarized as follows:
1. For better mowing, the most appropriate shape of piano-wire blade was of the disc diameter of 100mm, the wire diameter of 3.2mm with 8 pieces of wire of wire length of 70-100mm, respectively.
2. The flail type piano-wire blade was least abrasive under mowing work. An endurance test using concrete panel showed that it was not broken, but the tip of blade was worn out about 30mm against 5×104 blowing. Piano-wire blade could satisfactorily mow grass growing near concrete fence.
3. Piano-wire blade had an advantage over cut-away blade in rate of work and fuel consumption.
4. It was considered that the most desirable edge shape of piano-wire blade tip was of wedge angle of 90°.
5. An increase in abrasion of cut-away blade, resulted in an increase in cutting angle and large diminution of working rate.
Even if the blade was shaped ground, recovery of cutting quality was hardly possible.
6. Higher operating efficiency was indicated (edge shape of) at the wedge angle of 90° than that of 30°. In the case of high speed, the attempt of giving an edge to cut-away blade was made.
7. Nylon-wire blade was able to mow with safety, but we had difficulty to cut off grass as a result of shortening nylon wire.
8. We feel from the experiment described above that the piano-wire blade had possibility of practical use.View full abstractDownload PDF (1326K) -
Field Test Results of Tea-Plucker equipped with Automatic Position Control System for the Cutter Bar constructed for this Research WorkKenji NAKAGAWA, Fujio NAKANO, Kazuo HORIBE, Seiichi OSHITA, Kazuyuki K ...1980 Volume 42 Issue 1 Pages 85-89
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESS(1) For the use of automatic position control of cutter bar for tea-plucking machine, two control systems, the on-off control system with limit switch and solenoid valve and the feedback control system with electro-hydraulic servo-mechanism, were constructed and the performance of these two control systems was examined respectively by practicing the plucking test using the machine equipped with the control system in the tea garden.
(2) With the on-off control system, the accuracy of plucking depends greatly on the operation interval of limit switch, and good results were obtained without vibration when the operation interval of limit switch was 5mm or so and the vertical movement velocity of the cutter bar was about 0.03m/s. This control system was considered to be the most satisfactory system in view of its functional properties, manner of treatment and low cost.
(3) It was proved that the feedback control system with electro-hydraulic servo-mechanism was functionally for superior than the on-off control system. However, there may exist problems of treatment and cost on the use of the feedback control system, and this system cannot be offered to employ for the present.
(4) With both two types of the automatic position control systems for the cutter bar mentioned above, desirable position control of cutter bar should be done through the following procedure;
(a) Putting load of about 1g/cm2 on the sensing plate according to the tea shoot condition, and the cutter bar was setted at the same level surface as the sensing plate for a while.
(b) In the beginning, test plucking was practiced and according to its results, the relative position of the sensing plate and cutter bar should be corrected in this way; the sensing plate was brought down for deep skiffing and raised up for light skiffing.
The following would be pointed out; what tea plants are controlled to grow uniformly was very important for plucking tea leaves equally at the optimum plucking surface all over the tea garden.View full abstractDownload PDF (4542K) -
On the Method for Measuring Cracked Rice PercentageShinkichi YAMAGUCHI, Shingo YAMAZAWA, Kaichiro WAKABAYASHI, Toshiharu ...1980 Volume 42 Issue 1 Pages 91-97
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to investigate the stress cracking of rice grain during moisture adsorption and desorption (drying) processes, an examining method of rice cracking was discussed.
The experimental retults obtained were summarized as follows:
(1) The total number of severely and slightly cracked rice was little influenced by each of inspectors trained several times. The number of severely cracked rice, treated as one of damaged rice by the official inspection of Japan, was remarkably influenced by the inspectors.
(2) A x-ray technique for the examination of rice cracking could be applied effectively as well as the visual technique.
(3) After drying, the cracked rice percentage increased with preserving time of rice in an air tight container and reached the final percentage at a constant temperature within a couple of days. The final percentage depended upon the preserving temperature.
In this paper a method for measuring cracked rice percentage was proposed based on the above experimental results.View full abstractDownload PDF (1154K) -
On the Cracking of Kernels of Rough Rice during Cooling-Process after DryingYoshihiro MIWA, Hajime KOBAYASHI, Masakazu KANAMOTO1980 Volume 42 Issue 1 Pages 99-107
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis study was done to define the phenomenon which arose the grain crack during the cooling-process after the drying of rough rice.
Observation was made by the X-ray photographs and microphotographs.
In the first place, the rice of equilibrium moisture content 20.7% w. b. was dried until 13.6% w. b. with 50.6°C, 32.5% r. h.. Thereafter, 50 grains for one box from these dried rough rice were placed into two airtight cooling-boxes to expose them to the air conditions of 30.3°C, 80.3% r. h. and 30.3°C, 11.3% r. h., and so, grains in the condition of 30.3°C, 80.3% r. h. were moistened again, and grains in the condition of 30.3°C, 11.3% r. h. were dried still more.
The X-ray photographs were taken at regular intervals during the drying and the cooling periods of rough rice to determine the grade of the crack of rice kernels, and these cracks arose in all rice kernels within 48 hours of the cooling period by the observation of these photographs. While, we observed the mode of cracks on the surface of kernels which removed the rice bran by the microphotographs.
The following results were obtained.
1. The rice kernels didn't crack at the drying-process, but cracked at the cooling-process after drying.
On their cracks of rice kernels which still more dried at the cooling-process after the drying of rough rice;
2. Many cracked kernels were observed within 6 hours. The rate of cracked kernels increased from 21.4% to 29.0%. The rate of the big cracks which across the center of the kernel in a ring increased from 3.0% to 12.2%within 6-8 hours at the cooling-process.
3. These cracks were observed in the parallel direction to the short-axis of kernels. Many of cracks appeared on the ventral side of the central part of the long-axis of kernels.
4. The growth of cracks was rapid at the beginning of crack, and thereafter became slow.
5. Many fine wrinkles were observed on the ventral side of the surface of the kernel (by the microphotograph). It seemed that these wrinkles developed to the crack in over dried rice kernel.
On their cracks of rice kernels which moistened again at the cooling-process after the drying of rough rice;
6. These cracks arose in almost all kernels within 6 hours. The rate of cracked kernels increased 91.2% to 93.0%. The rate of big cracks in a ring increased 89.4% to 93.0% within 6-8 hours at the cooling-process.
7. These cracks were observed in the parallel direction to the short-axis of the kernel and on the central part of the kernel.
8. The growth of cracks was very rapid and their growth velocity was faster than that of the case of drying.
9. It seemed that these cracks appeared in the inner part of the kernel.View full abstractDownload PDF (3450K) -
Aptitude judgment of sorting person by applying Learning Curve, and effect of quality distribution in the lot of farm products on grading standardKouichi AKIMOTO, Suketoshi KURODA1980 Volume 42 Issue 1 Pages 109-113
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAptitude judgment as sorting person of farm products was investigated by means of Learning curve, and then effect of quality distribution in lot on a standard of judgment for grading was clarified. The results were as follows:
1. Degree of fluctuation of grading standard and reduction of that by training differed between individuals
2. On aptitude as sorting person was passed judgment by learning ratio and initial value that was calculated by applying Log linear model.
3. The standard of grading was affected by quality distribution in sample lot, which was severe when the lot contained a high percetage of high quality products and was soft when that did a small percentage.View full abstractDownload PDF (765K) -
Yutaka CHUMA, Tohru SHIGA, Kazuo MORITA1980 Volume 42 Issue 1 Pages 115-120
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to improve and mechanize the grading system of Japanese persimmon fruits, which was now relying on manual human sorting, the spectral reflectance of persimmons was measured.
The fundamental data were obtained as follows;
1. For the diameter of 20mm of sample port, the spectral reflectance intensity was not affected by the size of samples.
2. The largest change of the attenuance, i. e. log (1/R), occured at the absorption band of chlorophyll of 680nm.
The attenuance (Er) at 680nm had a linear regression with the chlorophyll content (Chl.) of persimmons, and the correlation was significant at 1% level. Chl.=0.00652×Er+0.00246
r=0.73
Therefore, the surface color of the persimmons could be evaluated by measuring the spectral reflectance at the wavelength of 680nm.
3. The spectral reflectance of the persimmons was affected by the peel and flesh of the thickness of 4-5mm below the surface. Furthermore, the attenuance increased rapidly as the thickness of peel and flesh decreased. These indicated that the spectral reflectance mainly depended on the body reflection of the peel and flesh within the thickness of 4mm.
4. The attenuance changed due to the orientation of the cheek of a persimmon. The difference of surface color on the location of a fruit was found not to be negligible. The spectral reflectance should be measured from various orientations of a fruit for the correct evaluation of surface color.
5. With the lapse of time after picking, the attenuance of unripe persimmons decreased near the wavelength of 680nm, but the attenuance of overripe ones increased at the whole wavelength from 550nm to 750nm. The additional measurement was required when the overripe persimmons were graded out from the unripe and the ripe ones because the attenuance showed the different change between the stages before and after full ripening.View full abstractDownload PDF (922K) -
Analysis of Filtration Characteristics by Parameter j, k of the Filtration EquationHiroshi SHIMIZU, Junichi TAKEDA1980 Volume 42 Issue 1 Pages 121-125
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSParameters j and k of the filtration equation of the report (I) were calculated based on the experiments of the report (II) and the following results were obtained;
(1) Calculation curves of the equation showed that the parameter j represented the choking strength of a filter opening (Fig. 3-7), and that k represented the choking velocity (Fig. 3-8).
(2) Values of j calculated for suspended solutions of swine waste were almost constant. The mean value of j was 2.0.
(3) Values of k varied with filtration conditions. The values decreased with an increase of the sieve mesh up 240μ and kept a lower constant value for the sieve mesh greater than 240μ. As to the effect of using filter assistant compared with without assistant, k decreased obviously for the body-feed assistant and slightly decreased for the pre-coat method but k increased for the combination of body-feed and pre-coat assistant (Fig. 3-3).
(4) Very little effect of suctions pressure Pf on the k value was seen except at 150mmHg (Fig. 3-4).
(5) As to the effect of initial density Wo, k decreased slightly with increase of Wo in case of 74μ filter with combination-feed of hull charcoal but had almost constant values in the case of 246μ filter without assistant.View full abstractDownload PDF (655K) -
Takashi TAKEZONO, Kensuke AMANO1980 Volume 42 Issue 1 Pages 127-133
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA study was made on the development of the solar greenhouse in the cold regions.
Theoretical and experimental analyses were made on the features of the collector with a transparent-heat-insulating layer installed in the greenhouse.
The effects of the factors related to the structure and operations of the collector were well predicted. The collector was effective even for the period of low level insolation.View full abstractDownload PDF (1057K) -
Ryo TORISU, Shigenobu KIMURA, Katsumi TASHIRO1980 Volume 42 Issue 1 Pages 135-140
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis study was initiated to investigate the effect of initial moisture content and air flow rate on high-rate composting of cattle manure at its early stage. A two-way layout statistical design was used for the experiment. The mean composting temperature of which influence of open air was eliminated was used as a criterion of aerobic decomposition of cattle manure. The following results were obtained through this study.
1. As the result of an analysis of variance, the contribution ratios of air flow rate, moisture content and their interaction for average composting temperatures were 48, 21 and 19 percent respectively.
2. During the initial phase of composting, the optimum aeration rate was 120 liters/min/m3 and the optimum moisture content was from 60 to 65 percent wet basis. In the case of this combination mean composting temperature of which influence of open air was eliminated was from 30 to 45°C at 1 percent level of significance. For the given set of conditions, the thermophilic temperature reached 73 to 76°C at the middle part of the composting mixture.
3. Moisture content and dried material weight of composting had little changes for each 48 hours incubation period. These results would be useful criteria for the design of windrow composting plant and applicable on small farms that must meet more strict environmental criteria.View full abstractDownload PDF (874K) -
Noriaki Ishizuka1980 Volume 42 Issue 1 Pages 141-148
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSWeather condition is one of the most important factors for determining an environment for agricultural production systems to be simulated. Actual weather data could be used as an input data but if several years of production simulations are necessary, this method will be cumbersome and expensive. It would also be difficult to obtain actual records for each location.
The weather model is for generating the daily climatic variables in order to investigate adaptability of agricultural production systems to a particular location.
The determination of Rain (>1mm) or No-Rain condition for the day was made by conditional probability computed from continuous and previons Rain or No-Rain days. The relative frequency distributions of daily rainfall amount in each month could be classified into three types; the small amount type, the medium amount type and the large amount type. The random numbers with the density function of daily rainfall are generated by the inverse transformation method and the random value is assigned to the rainfall of the day. The percentage of possible sunshine had a different density function whether it was Rain or No-Rain day. The sunshine duration of the day, therefore, is determined as the random number having the density function in case of either Rain or No-Rain. The daily average temperature could be described by a seasonal variance and a daily variance. Since the seasonal variance showed differnce trends every year, it was described by the mean of the seasonal temperature for several years and the yearly variance from it. The three order polynomials were used to predict the mean of the seasonal temperature and the autoregression functions were employed for the yearly variances and daily variances. The yearly and daily variances are also random variable. Therefore, the autocorrelated random numbers are generated to assign to them.
The weather model described above was used to simulate the climatic condition for Sapporo in order to test the model and compare its outputs to actual weather records. It is concluded that the model developed in this paper can be used to provide climatic variables for use in agricultural production simulations and that actual weather data for about 5 years are enough to determine the weather coefficients in the model, when a simulation period is within two decades.View full abstractDownload PDF (1138K) -
[in Japanese]1980 Volume 42 Issue 1 Pages 149-152
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (5250K) -
1980 Volume 42 Issue 1 Pages 153-176
Published: 1980
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (3203K)
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