The objective of this study was to investigate the characteristics of the evaporation rate, the plastic shrinkage and the compressive strength of concrete exposed to a rapid evaporation environment immediately after casting. Drying of concrete were conducted under a controlled chamber in which the temperature was mainfoimed at 30 ${\pm}$1$^{\circ}C$, the relative humidity 22 ${\pm}$1 percent, and the wind velocity 7 ${\pm}$1 m/sec. The compressive strength of concrete was tested after 28 days of standard curing. The results obtained are as follows: 1. The evaporation rate was the highest at the very beginning, was decreased as the drying progresses, and was kept almost constant after 6 hours. 2. The shrinkage of concrete was changed in three different rates for the concrete mixture having its slump vallue between 3.0cm and 7.5cm. 3. The plastic shrinkage was ended within 5 or 6 hours after casting, regardless of the water cement ratio. 4. The shrinkage was increased within the limit of slump values between 3.0cm and 7.5cm as the water-cement ratio was increased. 5. The evaporation was kept on even after the plastic shrinkage was ended. 6. Within the limit of good workability (slump value between 4.5cm and 7.5cm), the compressive strength of concrete was increased when the shrinkage rate was slow but it was decreased when the rate was rapid 7. From the result of this study it is recommended that (1) the water-cement ratio should be less as long as the workability of concrete is allowable; (2) the evaporation should be prevented at least for 4 hours after casting concrete.

This experiment of which aim contribute to plan irrigation system so as to increase forage crop yields, was conducted to estimate evapotranspiration amount of forage crops and to find out system of consumed water in a pasture-ground. The results obtained by this study are as follows: 1. The general weather conditions which, were closely related to the evapotrannpiration of forage crops were nearly same as those of the average year with the exception that temperature of May and June were slightly low. 2. According to the investigation of potential evapotranspirations (P.E) or forage crops and its changes during growing periods, changes of tenday P.E. were high significant according to the harvesting period. P.E of Alfalfa of which yield was the largest was the biggest. Althrough the correlations between P.E. and meteorological factors were irregular oming to three-time harvesting, correlation between ten-day evapotraspiration amount and copper plated pan evaporation or solar radiation was high positive significant. 4. Predicting formulas of P.E. were led by weather factors, and also relatione between P.E. and weather factors were showed as figure. from the these formulas, P.E. may be calculated by weather factors. 5. Predicting formulas of P.E. were led by mean temperature and copper plated pan evaporation, and by mean temperature and solar radiation. As computed values and measured values showed in figure, these formulas were high signiflent. 6. In the total consumed soil water duration of 10 days which, was non-rain period from 12th to 21th of August, Alfalfa was the largest 48.1mm, second, Orchard grass 40.1mm and Fescue 37.6mm, and Ladino clover was the smallest 37.1mm, also, order of each forage crop yield amound. was same to the abov. Order of soil moisture extraction rate of soil layer of all the for forage crops dulation of ten-day was soil layer 1 which was largest, soil layer 2, 3, and 4 Reviewing the the first five-day and the second five day, in the first five-day, order of that of all the forage crops was same to the above, but in the second five-day, that of soil layer 2 or 3 was more than the of soil layer 1.

본 논문은 Thrower의 양곡성능에 관한 예측 방정식을 차원해석법을 적용하여 유도하는데 있다. Thrower의 능률에 큰 영향을 미친다고 생각되는 인자들간의 관계식들을 Buckingham의 $\pi$이론에 의하여 구하여 졌으며 본연구에 사용한 Thrower는 현재 농촌에서 사용되고 있는 자동탈곡기의 Thrower와 유사한 형으로 제작된 것이며 실험에 사용된 시료는 벼의 경우는 통일벼와 미네히까리 품종이고 보리 품종으로서는 나맥이며, Thrower의 Impeller 직경, 속도 및 투입량을 변화시켜 가면서 각 시료에 대하여 양곡높이를 측정하여 그 예측방정식을 유도하였다. 본 논문에서 얻은 결과는 다음과 같다. 1. Thrower의 양곡성능에 지대한 영향을 미친다고 생각되는 주요 인자들을 Thrower의 양정, impeller의 직경과 속도, 투입량, 곡립의 밀도, 중력가속도등이라 간주하여 Buckingham의 $\pi$이론을 적용하여 이들에 관한 $\pi$항들을 결정하였으며 그 결과는 다음과 같다. {{{{ pi 1= { D} over {H } , pi 2= { { DN}^{ { 1} over {2 } } } over { { g}^{ { 1} over { 2} } }, pi 3= { Q} over { { g}^{ { 1} over {2 } } { rho D}^{ { 2} over {6 } } }}}}} 2. 실험에 의하여 구해진 $\pi$항문의 관계식을 합성하여 Thrower의 양곡성능에 관한 시료별 예측방정식을 구하였으며 이 식들은 아래와 같다. 통일 : $\pi$1=0.1223($\pi$2)-1.1813$\times$($\pi$3)-0.1864 미네히까리 : $\pi$1=0.1185($\pi$2)-0.9663$\times$($\pi$3)-0.1575 나맥 : $\pi$1=0.1599($\pi$2)-1.2350$\times$($\pi$3)-0.1382 3. 현재 농촌에서 사용되고 있는 자동탈곡기체 부착된 Thrower의 회전수, Impeller의 직경 및 투입량은 각각 1,100rpm, 30cm 및 150gr/sec 정도로서 이와같은 수준의 변량들을 기초로 하여 본 논문에서 유도한 예측방정식을 적용하여 Thrower의 양정을 산출한 결과, 통일벼의 경우는 2.6m정도였고 미네히까리 품종과 나맥의 양정은 각각 2.4m, 2.9m 정도였다. 이와같은 사실로부터 1m내외의 양정만으로 되어있는 자동탈곡기 Thrower의 경우 제작비절감, 소요동력 감소를 기하고 아울러 과립의 손상을 줄이기 위해서는 설계 또는 작동조건의 변경을 통해 Thrower의 회전수를 현재 수준이하로 줄일 필요가 있다고 판단되었다.

This thesis a result of theoretical and experimental studies on the shape of seepage line and seepage quantities in various inclined core walls. The value of this determination was examined and compared with the values of calculation acquaired to be based on Fukutas, Jin's and author's approximate equation of the theory. Thus the writer of this paper confirms that the seepage quantity can be decreased by changing the types of the inclined core wall and it's change of the slope.

Experimental work of batch-type dryer was conducted to develop its optimurm operating conditions by analyzing the major factors which affect the drying performance. A laboratory batch-type dryer was constructed and tested for various levels of heated-air rates, and depths of grain deposit. Tong-il rice variety having the initial moisture content of approximaely 23 per cent in wet basis was used for the experiment. The criteria selected for establishing the optimum operating condition were the drying performance rate, the thermal efficiency, and the operational cost of the dryer. The results of the study are summarized as follows: 1. The performance rate of dryer for a specific operating condition was defined as total amount of material dried per hour when the moisture content of grains in the upperlayer reaches to 16 per cent in wet basis. The optimum operating conditions as viewed in the rate of drying performance could be justified by functional realtionship between the depth of grain deposit and air flow rate. In other words, there was a definite depth of grain deposit for a given air-rate which make the dryer performance maximum. The optimum grain depth for the batch-type dryer with 3.3㎡ loading area and with the attached axial fan was about 35cm. 2. The thermal efficiency for the dryer was evaluated by the ratio of the latent heat required to evaporate the grain moisture to the heat input required to raise the ambient air-temperature to 40 degree centigrade. The optimum operating condition as viewed in term of thermal efficiency analyzed was that grater depth and lower air flow-rate may be desirable. This condition is contracted with the optimum condition as viewed by the dryer performance rate. 3. The annual operating cost of batch-type dryer was analyzed for different annual hour of use and for different operation condition. The optimum condition as viewed in terms of operating cost was almost identical to one as viewed in terms of dryer performance rate. Therefore, the most economical use of batch-type dryer for the same annual operating hours can be obtained when the dryer operated in the condition of maximum dryer performance rate. Increasing the annual operating hour may be desirable to cut down the dryer operation cost, since the annual hour of dryer use is much sensitive to the operating cost than any peractical conditions of dryer operation. 4. The most desirable operational condition as justified by combining all the criteria, dryer performance rate, thermal efficiency and annual operating cost, could be concluded to operate the dryer in the condition of maximum performance rate. The condition in general is identical to the lowest operation cost for a given annual operating hour.

Alluvial plain of the coast of Kum river tail were found as being mostly consisted of weak foundation. The settlement of the ground, density and change of moisture content which were formed by the load due the construction of earth works were disclossed by the field investigations and laboratory tests. The results are as follow, 1) Banking materials are SM and soft soil stratum is CL. 2) Field moisture content; Wf=19-1.37c c; percentage of clay (less than 0.005mm) 3) optimum water content and maximum density of banking materials; rt=2.15$\mid$0.0165W(12%24%) 4) Density and moisture coutent of banking materials; rt=2.146-0.0095W (8%50%) 5) Density and moisture content of weak foundation; rt=2.06-0. 007W After construction (20%50%) Befor construction (40%60%) 6) Load and settlement of weak foundation; Everage settlement ratio; 12% of actual load p Maximum settlement ratio; 19% of actual load p Minimum settlement ratio: 5% of actual load p 7) Relation of cohesion and unconfined compression test value; c=1/2qu (qu<0.5kg/$\textrm{cm}^2$) c=1/3qu (qu<0.5kg/$\textrm{cm}^2$)