This study discussed the effects of inclined interface location to apply the design of inclined interface of composite materials subjected to shear loading. The fracture parameters are analyzed by finite element method of ANSYS. As a results, If in case of the angle of inclination is 45 degrees, inclined interface is longer and the crack tip is closer, the less the crack suppression effect. If the inclined interface location is a more than twice the length of the inclined interface, the effect of suppressing crack propagation are constant regardless of the location. In case of the inclined interface is longer and the crack tip is closer, the cause of increase of energy release rate is a due to the increase of shear stress. If in case of the angle of inclination is 90 degrees, inclined interface is closer to the crack tip, the better the crack suppression effect. If the inclined interface location is a less than twice the length of the inclined interface, the effect of suppressing crack propagation are dominant. And if the inclined interface location is a more than twice the length of the inclined interface, crack suppression effect is gradually reduced.
This study was discussed with the friction effects due to surface roughness of the interface between the base material and a reinforcement at the downward inclined interfacial crack under shear loading. The fracture parameter are analyzed by finite element method of the ANSYS. As the friction coefficient of the surface is assumed zero and 0.3, the fracture is analyzed. This study was analyzed with inclination angles about 0 degrees, 45 degrees and 90 degrees. As the results, at the inclination angle of 0, the energy release rate is reduced by about 3%. About 16%, and 2% are decreased at 45 degree and 90 degree respectively. If the inclination angle is 45 degrees, the friction effect by the sliding resistance between the interface was found to be most effective.
Micro structure observation for low carbon steel base material and heat treatment(annealing), performing a tensile test and impact test, the specimen after the impact test is intended to evaluate the crack propagation characteristics by performing a fractal dimension analysis. The tensile strength of the base materials were observed higher compared to the heat treated materials, impact absorbed energy of heat treated materials was a higher than base materials. Impact Test and fractal dimension of the side of the test specimen was shown significantly more test temperature increases, heat treated material was higher than the base material
In this study, the crack initiation and propagation behavior of interfacial crack in bimaterial are discussed. Normal crack opening displacements(NCOD) and stresses are analyzed by finite element method using ANSYS and used for extracting fracture parameters. The energy release rates can not explained the initiation and crack propagation velocity of interfacial crack. Initial velocity of crack propagation is dependent upon the normal and shear stress behind of crack tip. The crack propagation velocity of interfacial crack is very dependent upon the normal and shear stress behind of crack tip. In case of negative shear displacements increase in interfacial crack, initiation delay of crack propagation is dependent upon the negative shear stress ahead of crack tip due to the suppressing of crack opening. In case of positive shear displacements increase in interfacial crack, initiation delay of crack propagation is dependent upon the stress behind of crack tip due to the stress decrease. The fracture toughness increase is due to the initiation delay of crack propagation.
Competitive ELISA methods were used to measure the level of aflatoxin M1 (AFM1) from urine in 1008 Korean adults. Subjects were selected by random sampling in all areas of Korea, except Cheju-do. The recovery rate of AFM1 using this method was 105% (73-124%). The geometric mean of urinary AFM1 in all subjects was 3.43 pg/mL (3.67 ng/g creatinine). The level of AFM1 in males was statistically higher, compared with female subjects. However, the levels of AFM1 did not differ according to age. Subjects in Chungbuk-do showed the highest urinary AFM1 concentration, whereas subjects in Kyeongnam-do showed the lowest concentration. Assuming an excretion rate of 5%, this AFM1 excretion corresponds to approximately 0.1 microgram/day in Korean adults.
In order to select suitable fertilizer level and sowing rate of Dangyo #8(hybrid) rapeseed at the southern area of Korea, two varieties of Naehanyuchae (Normal) and Dangyo #8(hybrid) rapeseed currently grown for oil production by two fertilizer level with 10-8-8 kg/10a and 15-8-8 kg/10a and three sowing rate with 500 g/10a, 1,000g/10a and 1,500g/10a with relatively high yield was grown at the same condition yield and yield components were observed. Dangyo #8(hybrid) rapeseed was superior to oil-eed rapeseed for yield at the 15-8-8 kg/10a of fertilizer and 1,500 g/10a of sowing rate. Fertilizer level, N-P2O5-K2O = 15-8-8 kg/10a and sowing rate, 1,500 g/10a showed somewhat higher value in two varieties of Naehanyuchae(Normal) and Dangyo #8(hybrid).
This study was conducted to investigate the relationships between yearly variations of meteorological elements and yearly variations of productivity in hot pepper. In addition, correlation coefficients among the yields and yield components were used to find out the relationships between meteorological elements and productivity. Yearly variation of the mean air temperature in May and July showed large with coefficients of variation(C.V.) of 25.0,8.9%, respectively, but the variation of the duration of sunshine in May were relative small. Yield and plant height was greatly with C.V. of 7.14,11.6%, respectively, diameter of fruit showed more or less C.V. of 2.28% and length of fruit showed less variation. Correlation coefficients between maximum temperature in period of cultivation from May and yield are positively significant at the level of 1 %. Correlation Coefficients between precipitation in period of cultivation from May to August and yield are negative significant at the level of 5 and 1 %, respectively. Correlation coefficients amount the plant height, length of fruit, diameter of fruit per plant, and seed yield were positively significant at the level of 1 %, respectively.
To determine as optimal sowing time of forage rape in spring time in southern areas of Korea, forage rape cv. Velox, the highest yielding variety among introduced varieties of forage rape, was grown under five different sowing times. Yield components such as plant length, number of branches and number of leaves etc. were higher at the sowing time of Mar. 15 and Mar. 25. The plants sown at Mar. 15 and Mar. 25 also showed highest fresh and dry matter yield. When plants were grown under later sowing time, they showed higher values in content of crude protein and lower values in contents of crude fiber such as Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), cellulose and lignin. There was no relationship between variation of In Vitro Dry matter Digestibility (IVDMD) and sowing time. The plants sown at Mar. 15 and Mar. 25 showed highest digestible dry matter yields.
The 129 soybean genotypes were collected in 43 island locations from January to May 2001. Seeds of 129 genotypes collected were analyzed for crude protein and fatty acid composition contents. The crude protein content was averaged to 41.1 % and ranged from 37.4% to 44.4%. The average palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid content were 12.0%, 4.0%, 23.2%, 55.5%, and 7.9%, and the ranges of those were 10.0% to 15.0%, 3.0% to 4.8%, 21.7% to 25.5%, 50.2% to 58.3% and 7.0% to 12.0%, respectively. Heritabiliries of palmitic acid, oleic acid, linoleic acid, and crude protein were higher, but that of stearic acid and linolenic acid were relatively lower. The genotypic correlation coefficients between crude protein and oleic acid showed highly positive correlation, but that of linoleic acid showed highly opsitive correlation, but that of linoleic acid showed highly negative correlation and also palmitic acid, stearic acid and linolenic acid showed negative correlation.
In order to obtain basic information for selecting early maturing rice varieties which is suitable for early cropping before Alisma plantago in the southern part of Korea. Six rice varieties were grown from May to August in 2002 at Youngjeon Experiment Field, Sunchon and yield components and yield of plants were investingated. Early maturing rice cv. Grubyeo showed higher rough rice yield than any other varieties used in the experiment. It showed high yield components, such as culm length, panicle length, number of panicles per plant, number of spikelets per panicle and ratio of ripened grains. Therefore, it was concluded that Grubyeo was the most suitable variety with high yield for the cultivation before growing of Alisma plantago at the southern part of Korea. The heritability of culm length number of spikelets per panicle and rough rice yield were high and that of panicle length number of panicle per plant, ratio of ripened grain and 1,000 grain wt. of milled rice were low. According to the result of path coefficient analysis, characters highly correlated with rough rice yield showed large direct effects on rough rice yield.