The traction performance of tractor, especially the mutual relation between the ratio of weight difference on each side of wheels and the ratio of eccentricty l′/l was studied, where l is a half of tread and l′ is the lateral distance from the center of driving axle to the hitch point.
1) When the test tractor is pulled, traction resistance and side force are calculated by the eq. (1) and (2) shown in the report 2 by replaceing the ratio of weight difference λ with the ratio of virtual weight difference λ_t shown as follows;
λ_t=λ+0.167V/t
2) When the test tractor is driven, traction force and side force, or driving force are calculated by the equations in the report 2, using the
ratio of virtual weight difference λ_p, or λ_d, instead of λ, respectively, The relations between λ and λ_p, or λ_d, are as follows;
λ_p=λ+l′/l/1+l′/lλ
λ_d=λ-l′/l1-l′/lλ
These equations can be found out easily, imagining the virtual wheel which have the hitch point at the center of the driving axle as mentioned in the report 5.

抄録全体を表示

To establish the predicting method of trafficability of the peat paddy field, authors investigated the physical property of soil and running performance of various tractors, namely track type, half track type and two and four wheel drive tractors. The results are as follows;
(1) Bekker's equation that predicts the tractor sinkage by small rectangular plate is inapplicable, because soil is not considered homogeneous up to the depth of loading area of the tractor.
(2) There are high correlations between cone penetrating resistance and sinkage of tractor, and also sinkage of rectangular plate and sinkage of tractor. Hence it is possible to predict the tractor sinkage by cone-penetrometer or soil hardness tester with rectangular plate.
(3) Cone index at the depth of tractor sinkage was similar to vehicle cone index for various type of tractors. Hence it seems possible to predict the trafficability on the peat paddy field by cone index and vehicle cone index.
(4) Tractor sinkage was the function of n th power of travel reduction, and following empirical formulas were obtained.
Track type tractor Zt=5.22 S^0.282
Half track type tractor Zt=2.00 S^0.598
Two wheel drive tractor Zt=0.653 S^0.758
Four wheel drive tractor Zt=1.98 S^0.570
where Zt is tractor sinkage in cm and S is travel reduction in per cent.

抄録全体を表示

When heavy oils were treated by ultrasonics, the effect of the action of cavitation were as follows.
1) Owing to the increase of A. P. I. (American Petroleum Institute) gravity and the decrease of kinematic viscosity, calculated cetane numbers were higher than untreated fuels; so it was thought that the starting capacity of treated fuels would be better than untreated ones. Their flash points were higher and penetration were the same.
2) The sludge contained in B heavy oil, B heavy oil (LS-Low Sulfer) and (LS) B heavy oil (for ceramics) could be separated thoroughly as shown in Fig. 5-(3).
3) The ratio of the time needed to pass the filter paper on untreated oils and treated oils of B heavy oil, B heavy oil (LS) and LSB heavy oil were 1:4.5, 1:7 and 1:3.5 respectivly. Therefore treated oils were faster than untreaced ones.
4) Treated heavy oils were atomized minutely as shown in Fig. 6-(1)-(4). Their viscosities were lower than untreated ones. These factors are important in advancing combustion speed for a high speed engine.

抄録全体を表示

The automatic rice husker which has beed widely in Japan consists of some unit processes so called husking, separating and elevating units. The unhulled rice grains are fed through in these units and are changed into the rough rice grains. The static and dynamic characteristics of these unit processes are represented by Ki and Gi, which are the static gain constant and the time behaviour of grain flow rate respectively. The process system of a test husker (3 inch width rubber roll type) is shown by a block diagram.
Results of some experiments on static relationships between various operating conditions of each unit process and grain feed rate are stated in this report. Ki varies by grain flow rate as well as operating conditions because the husking ratio is the system parameter. To determine the grain flow rate and Ki at given operating conditions of the husker, the mathematical models are introduced from these results.
The dynamic characteristics of each unit process shall be reported in the next paper.

抄録全体を表示

A commercial prototype hydrocooler was designed and constructed by the Food and Agricultural Engineering Laboratory, University of Kagoshima, Kagoshima-shi, Japan.
This report presents the fundamental design features and cooling capacity of the prototype.
The prototype can be operated as immersion or flood cooling system.
In the immersion-type cooling system, chilled water in the cooling tank is circulated by an agitating propeleer, ce Products under the conveyer are immersed in the chilled water from inlet to outlet.
In the flood-type, chilled water is pumped to a perforated flood-pan, which showers the chilled water to products on the conveyer in the cooling tunnel,
1) When a 12.7mmφ perforated flood-pan was used, it could most efficiently cool products which were fed at a flow-rate of 0.65m³/min. per square meter of conveyer, under the conditions studied.
2) It is not efficient to cool commodities contained in wire-band-crates.
3) Several graphs were made for cooling time of products. Figures 10 and 11 could be used to predict the time required to achive temperature reduction of carrots and radishes by the prototype, when initial temperature of products and chilled water temperature were given.
4) The prototype has a capacity to cool 700-800kg/hr of carrots or 540-620kg/hr of radishes from 20°C to 5°C, with 1.0°C chilled water.

抄録全体を表示

This paper reports design, construction and performance of Stage type Forced Air Cooler, which uses the principle of exposure of the surface of individual products to a cold air blast as the products move on a conveyor.
1) To achive an efficient system design and also a desirable product environment, the precooler was divided in three stages and designed so that the temperature of air and products were progressively reduced from the entrance (1st stage) to exit (3rd stage) of the cooler. At each stage the standard cooling temperature was 10°C (1st stage), 0°C (2nd stage) and -10°C (3rd stage) respectively, and each was adjustable within ±5°C.
2) It has a capacity to cool up to 400kg of products in bulk from 25°C to 4°C in an hour.
3) Each unit is equipped with a limited load fan which has a variable-speed drive and a capacity to deliver from 100 to 160m³ per minute.
4) The conveyor is constructed of stainless wire mesh having 150kg per m² strength and equipped with sideplates to accomodate loose products up to 20cm in depth. Drive mechanism consists of a 4 to 1 ratio variable-speed drive to provide a cooling tunnel with retention time of 15 minutes to 1 hour.
5) For citrus Unshu whose average diameter was 5.5cm, the value of m (hr^-1), the gradient of logarithm on cooling curve, was 2.17 (hr^-1) with the air velocity of 3.4m per sec.
6) The difference in citrus Unshu cooling rates between upper and lower layers of bed (15cm-products depth) was small, but for Oranda Endo the difference was large when static pressure did not exist between the product bed (10cm).
7) We discussed the procedure of determining adjustable elements using the value of m (hr^-1), such as cooling temperature, air volume and conveyor speed when the cooler is operated for various products.

抄録全体を表示

In general, the heat-drying method of grain has some disadvantages results in deterioration.
These studies have been tried to prevent such faults and to investigate experimentally on dehydrofrigidation method for storage of grain. Based on allowable storage time which was dependent on moisture content and temperature of grain, this paper presented the cooling and drying process of deep bed grain.
1. The temperature of 5-6±1°C and moisture content of 20% was adopted as most applieable storage condition.
2. The time required for the unhulled rice (about 300kg) of the initial grain temperature of 15°C and the moisture content of 25-30% to reach the above condition was 4 to 20 hours in cooling and 40 to 275 hours in drying, under air temperature of 5-6±1°C, relative humidity of 70-90±5%, and air flow rate of 0.5-8m³/min.
3. The reductions of moisture content and temperature in drying and cooling process of deep bed grain were expressed by equations (1) and (5). Constant numbers k and h were shown by following equations.
k=0.0018U^0.638 to 0.0054U^0.638
(R. H: 90 to 70±5%)
h=0.18U^0.84
(air velocity: 0.55 to 8.8m/min)
4. Drying rate was influenced by air velocity and relative humidity, particularly the latter is more effective.
5. Cooling rate was increased by increasing air velocity and relative humidity.
6. The time lag of cooling in each layer varied inversely with the increase of air flow and was in direct proportion to the increase of relative humidity. At the beginning period of cooling, temperature rise was seen in the upper layer for a short time, but soon each layer was cooled at the identical rate.

抄録全体を表示

Several fruits and vegetables were shrink-film wrapped, and the effects of the wrapping and heat-tunnel treatment on the cooling rate and quality of the produces were compared with the conventional film-wrapping, overwrapped but unheated ones.
The results were as follows:
I. Cooling rate of overwrapped produces.
1) Cooling rate of produces, shrink-film wrapped, were about the same as that of conventional film-wrapping.
Produces, unwrapped or wrapped with perforated film, cooled somewhat faster than those of film-wrapped or unperforated-film wrapped respectively.
2) Produces wrapped with a thinner film cooled faster than with a thicker film.
A definite difference in cooling rate was not seen between the produces wrapped with vinyl-chloride films and with polyethylene films when the film thickness was the same.
3) When produce was stored in a polyethylene bag, the weight loss during the cooling period was about on half that of unwrapped produce.
4) Produce wrapped with perforated shrink-film was vacuum-cooled faster than the one wrapped with non-perforated shrink-film.
During vacuum-cooling, produce wrapped with non-perforated shrink-film lost by 1 to 2 percent less water than unwrapped produce, and slower cooling rate was caused by the less water loss.
II. Effect of the operation of shrink-film packaging on produce quality:
1) The effect of heat-tunnel temperature on the quality varied much with the kind of produce: The heat-tunnel temperature effected much on the marketability of Chinese cabbage, Lettuce, and did not effect much on Cabbage.
2) Quality of vegetables deteriorated with the exposure time in heat-tunnel.
III. Effects of film-packaging on marketability of produces were investigated. 0.018mm thick vinylchloride and polypropylene films were used.
1) Onion:
The use of film wrapping, especially shrink-film wrapping, inhibited germination of the onion during the test period and preserved marketability. On the other hand, the decay developed day by day after 10 day.
2) Carrot:
The deterioration of quality and weight loss of wrapped carrot and of shrink-film wrapping were less than those of non-wrapped carrot.
3) Potato:
Tight wrapping with film such as shrink-film stimulated germination of the potato. Conventional film wrapping (perforated 16×5mmφ) of the potato stimulated less germination and showed less weight-loss.
4) Lettuce:
Conventional film wrapping of lettuce and Chinese cabbage maintained better marketability than by shrink-film wrapping. Non-wrapped lettuce and cabbage faded and wilted ramarkably day by day.
Severe decay developed in a week by shrink-film packaging.
5) Citrus-Unshu:
Film wrapped Citrus-Unshu developed severe decay and deteriorated marketability toward the end of room preserving season in the first and second ten days of March.

抄録全体を表示

The relaxation spectrum curves for apples and potatoes were determined from the relaxation test, in which the product in natural shape was loaded between parallel plates until the deflection reached some predetermined value and the force required to maintain the deflection was measured and recorded as a function of time.
For estimating the relaxation function from the recorded relaxation force, the following two methods were introduced:
1) Hertz's contact theory was extended to the viscoelastic case by generalization of Alfrey's theorem saving that in the case of the second boundary value problem for the non-homogenious strain in isotropic compressible viscoelastic media characterized by linear relations between the components of stress, strain and their derivatives with respect of time, the strain distribution was identical with that in an compressible elastic material under the same surface displacement. From these results, we derived the following equation by which to evaluate the relaxation function of the product:
φ(t)=μp(t)/p
where φ(t): the after-effect function.
p(t): the compressible force recorded as a function of time.
p(t): the calculated compressible force in a compressible elastic body of the same shape.
μ: the modulus of rigidity.
The after-effect function in compression was determined from the above-mentioned after-effect function multiplied by 2(1+ν).
where ν: Poisson's ratio.
2) The method of O'brien, M., Gentry, J. P. and Gibson, R. C. for determining the modulus of elasticity was extended to the viscoelasticity and the ellipsoid of revolutionshaped material whose center axis being parallel with the compression plates and the relaxation function was determined by the following equation:
φ(t)=p(t)/(α2D₁/D₂)
where α: the deflection.
D₁: the diameter of the product.
D₂: the length of the center axis of the product.
From the relaxation function, the relaxation spectrum was determined by the method of Alfrey's approximation and Schapery's direct method of approximation.
The Poisson's ratio in Hertz theory was measured by using the rosette type strain gage.

抄録全体を表示

The bunches of the grapes of Campbell-Early variety were shrink-film packaged to prevent the grains from falling off, and the effects of the packaging on the grapes were measured. The results were as follows:
1) The pull off test in which the grains were pulled off one by one through a spring balance showed no decrease of the resisting force in the case of the shrink-film packaging although the non-packaged grapes showed the remarcable decrease. The vibration test in which the three bunches of the grapes were vibrated in the box on the vibrator with acceleration of 1.0g for nine minutes to determine the percent of the grains remained on the bunches also showed the similar results. It was thought that the effect would be caused by the moistureproof action of the film controlling the moisture evaporation from the stem.
2) The shrink-compressive action of the package supported the grains and perfectly prevented the grains from vibration.
3) The color of the stems was well preserved in the case of the shrink packaging, and the effect was strengthened by cooling. The weight loss of the bunches was markedly controlled by the packaging, too.

抄録全体を表示

1) In the soaking of the whole seeds of soybean (Toyosuzu), dwarf red cranberry and white kidney, the maximum difference of moisture content was observed among the four sections within the seed at 1 or 2 hours after soaking (Fig. 6-1, 6-2, 6-3).
2) It was also found that the difference of moisture content which was obtained through one of the four local surfaces had a similar tendency to that observed in the soaking of the whole seeds. Therefore, the difference of moisture content within the seeds may be caused during the first 1 to 2 hours by the difference of the up-take of water through the surface of the seeds, and after the maximum difference is reached, by the diffusion of water within the seeds (Fig. 8-1, 8-2, 8-3, 10-1, 10-2, 10-3).
3) The manner of water diffussion within the seed suggests that water may move from the portion of radicle on finally to that in a diagonal position, which is fully explained as z-type (Fig. 7).
4) Soybean seeds which had originally a thinner seed coat than dwarf red crauberry and white kidney did not attain a high moisture content in the early hours of soaking.
5) Up-take of water was the greatest from the pinhole made on the surface adjacent to the hilum of seeds, while was the least from the pinhole made on the surface in the middle of the cotyledon (Tab. 3-1, 3-2, 3-3).
6) There was not so great a difference in up-take of water between the seeds with a pinhole and those without it.

抄録全体を表示

In order to find the more economical method of evaluating the quality of agricultural products, measuring electrical properties of the products was conducted.
Results obtained by measuring static bioelectro-potential difference (V_c) and bioelectric current (A_c) of cucumber and tomato at harvest and under preservation were as follows.
1. Both measuring at harvest and preservation, the experimental values V_c and A_c of materials had no relation with their to weight, length, and volume. So, it can be said that biophysical-chemical characteristics of quality instead of size and weight were measured.
2. At harvest, for cucumber, an approximate equation between V_c and A_c was
A_c=1/3200V_c² (Fig·5)
and for tomato, both experimental values V_c and A_c of full riped materials indicated comparatively larger than hard riped.
3. The variances of experimental values V_c and A_c under preservation were shown in Fig. 8 and 9. In the order of storage temperature, peak values marked by (*) stars were observed, and deterioration of quality of external apperance was clearly recognized 0.5 to 2 days after the appearance of the peak. Therefore it is considered that the peak values indicate the internal deterioration of quality.
4. Since there are many unsolved problems in bioelectrics, various studies in chemical analysis, chromatography and simulative method will be required.

抄録全体を表示

1. Fall tests: Various compressed wafers were dropped on a steel plate from 1.5 meter height next day or on the 50th day after extruding, and the following results were obtained concerning the collapse of those wafers.
(1) If the forming size is equal, the durability of wafer increased with increase of final dry matter density ρd and also with increase of moisture content at hay forming if ρd was the same.
(2) The orchardgrass wafer was more durable than the ladinoclover wafer. The former was difficult for feeding and packing because its fiber was stiff, thick and long, and collapsed mainly by extruding, whereas the latter often contained little leaves and broke mainly by cracks.
(3) The large, wet, heavy wafer was not durable for the reason of its large shock energy.
(4) Chopped hay wafers were not practical because their durability, when compared with that of original hay wafers, decreased considerably with decrease of fiber length.
(5) The durability of cross cut wafers of ladinoclover with large ρd was almost equivalent to that of original wafers, but that of orchardgrass with stiff, thick and long fiber was slightly reduced from that of original one.
(6) From many view points, the wafer of medium moisture content and small ρd (=0.8), and also of large diameter and short height was desirable for durability.
(7) It was considered that the fall test was a desirable method to indicate the durability of wafer because the conditions of fall test resembled that of pactical handling of wafers.
2. Vertical and horizontal one-axle compression test:
(1) At the vertical compression test, resistance-displacement diagrams showed four forms. The resistance, generally, arrived at the collapse strength of fiber, after passing through the compressive shearing fracture point as a wafer block. At the horizontal compression test, the fracture point as a wafer block was not clear.
(2) The fiber was broken to pieces at the collapse strength point, and this strength value under medium moisture content was larger than that of compressive shearing fracture of wafer block.
(3) The ρd of wafer had little influence upon the compression strength, which were higher as the moisture content was lower, and these characteristics were contrary to that of fall tests, therefore, the compression test was not desirable as an indication method of durability of wafer.
3. Cutting resistance: The cutting resistance value on the cross-section of wafer was very small and hardly influenced by any conditions of hay or cutters, therefore, the continuous compressing and cutting method was considered to be useful.

抄録全体を表示