• Journal of Biosystems Engineering
• /
• v.2 no.1
• /
• pp.55-55
• /
• 1977

This experimental work was conducted in order to find out the optimum time of harvest of Japonica-type(Akibare) and Indica-type(Tong-il) rice variety for three harvesting systems by investigating the harvestirg losses and milling quality. The study was also concerned atout the nature and amount of grain losses incurred during the each sequence of post-harvest technologies, and based on these results, a modification of existing systems giving a minimum grain loss was attempted. Binder, combine, and traditional harvesting systems were tested in this study and five grain moisture levels were disposed according to the decrease of grain moisture. The results are summarized as follows: 1. The total losses of Akibare variety were ranged from 1.1 to 1.5 per cent for the traditional harvesting system, 2.1 to 4.8 percent for the harvesting system by use of binder, and 2.8 to 4.3 percent for the harvesting system by use of combine as the grain moisture content was reduced from 24 to 15 per cent. Milling recovery of the harvesting system by use of binder, 74.8~ 75.7 percent, was a little higher as it was compared to that of traditional harvesting system, 74. 3~75. 0 percent, and that of the harvesting system by use of combine, 73.8~ 75.0 per cent. Head rice recovery of mechanically dried paddy samples was higher than that of sun-dried paddy samples. 2. The total losses of Tong-il variety were ranged from 3.8 to 5.0 per cent for the traditional harvesting system, 5.2 to 10.0 percent for the system by use of binder, and 3.0 to 5.0 perent for the system by use of combine as the grain moisture was reduced from 28 to 16 percent.

• Journal of Biosystems Engineering
• /
• v.2 no.1
• /
• pp.56-80
• /
• 1977

This experimental work was conducted in order to find out the optimum time of harvest of Japonica-type (Akibare) and Indica-type(Tong-il) rice variety for three harvesting systems by investigating the harvesting losses and milling quality. The study was also concerned about the nature and amount of grain losses incurred during the each sequence of post-harvest technologies, and based on these result, a modification of existing systems giving a minimum grain loss was attempted. Binder, combine, and traditional systems were tested in this study and five grain moisture levels were disposed according to the decrease of grain moisture . The results are summarized as follows ; 1. The total losses of Akibare variety were ranged from 1.1 to 1.5 per cent for the traditional harvesting system , 2.1 to 4.8 per cent for the harvesting system by use of binder, and 2.8 to 4.3 per cent for the harvesting system by use of combine as the grain moisture content was reduced from 24 to 15 percent. Milling recovery of the harvesting system by use of binder, 74.8 ∼75.7 percent, was a little higher as it was compared to that of traditional harvesting system, 74.3 ∼75.0per cent, and that of the harvesting system by use of combine, 73.8 ∼75.0 per cent. Head rice recovery of mechanically dried paddy samples was higher than that of sun-dried paddy samples. 2. The total losses of Tong-il variety were ranged from 3.8 to 5.0 per cent for the traditional harvesting system, 5.2 to 10.0 percent for the system by use of binder, and 3.0 to 5.0 per cent for the system by use of combine as the grain moisture was reduced from 28 to 16 per cent. 3. Milling recovery of Tong-il variety harvested by the traditional harvesting system was 72.3 ∼73.6 percent and it was lower when compared to that of 72.3∼75.0 per cent harvested by binder, and 73.0∼74.6 percent harvested by combine. 4. Head rice recovery of Tong-il variety harvested by the traditional harvesting system (58.

• Journal of the Korean Wood Science and Technology
• /
• v.40 no.4
• /
• pp.287-293
• /
• 2012

This study was carried out in order to compare nail shear strength between domestic plywood and imported OSB for structural sheathing members as infill wall of wooden construction. The differences of nail shear strength between parallel-to-grain direction and perpendicular-to-grain direction of sheathing material to frame material were distinct at the plywood composition. The shear strengths of plywood and OSB with nail met current design values. The plywood of P-4 type, which uses MLH at surface layer and constructs 7 ply, showed greater than OSB regardless of grain direction of sheathing material to frame material. When the plywood as sheathing material to frame material was used, it was found out that the overall construction of perpendicular-to-grain direction of plywood had greater nail shear strengths than the construction of parallel-to-grain.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.1
• /
• pp.34-44
• /
• 1996

Several major agronomic traits of 4 isogenic lines for tillering(Kindred, Morex)were investigated under the different seeding rates and seedling mortality grown in the pots. The normal-tillering phenotypes had higher grain yield(46％) and leaf area index(56％) than their uniculm isogenic counterparts. The assortment rate(69％) and 1,000 grain weight(27％) in uniculm type were greater than the normal type. Uniculm plants were earlier in heading(4∼8days) and maturing(2∼3 days) dates compared with their counterparts. The grain yield was fitted to linear regression, ranged 0.659g to 0.5g per spike number. On increasing the seedling mortality rates, the grains per spike and 1,000 grain weight were slightly decreased, but the grain yield per plot was decreased markedly because of decrease of spikes per plot. The assortment rate, leaf photosynthetic capacity and reproductive tiller number were increased with increase of seedling mortality. The grain yield was largely dependent on the number of spikes per plot on occurrence of seedling mortality. For the uniculm genotypes to be introduced and bred into a present leading variety, the isogenic lines were precisely tested in the open field for a couple of years.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.339-339
• /
• 2017

The long grain rice varieties adaptable to South-east Asia tropical regions were tried to develop in Cambodian Agriculture Research and Development Institute (CARDI), Cambodia. The final goal is to develop rice varieties which can culture in diverse environmental conditions of tropical regions of South-east Asia under climate change. We collected and evaluated for agronomic traits of 131 rice germplasm from Cambodia, China, India, Indonesia, Myanmar, Philippines and Vietnam in CARDI. We selected core germplasm including leading varieties of target countries and made 813 F1 cross combinations between leading varieties of each country and promising germplasm of high yield potential, resistance to biotic/abiotic stresses, aromatic rice, and so on. Out of 607 F1s evaluated to heading date, plant type, agronomic traits, and grain type, 106 F1s selected and advanced to F2 populations. 106 F2 populations were evaluated to major agronomic traits, grain type and yield-component traits, and selected 2,560 plants in 62 F2 populations. During six seasons in 2014~2016, the lines of F3 subsequent-generation were cultured a total of 6,256 lines. In yield trial for promising lines in F5 generation, the growth duration from sowing to harvesting was 97~114 days. These lines were 88~129 in number of grain per panicle, an average of 84.6% in the range of 79.3~91.9% in the percentage of ripened grain and 17.5~22.8g in 1000-brown rice weight. The rough rice yields were in the range of 4.33~6.06 ton/ha with an average of 5.23 ton/ha. The yield was increased to 5~47% than Chulsa and 12~41% than IR66. Five lines, KR54-28-1, KR55-14-2, KR57-5-2, KR67-57-2 and KR128-19-1 were 5.33~6.06 ton/ha in rough rice yield. These high yield potential lines would be evaluated to adaptability in Cambodia, Laos, Myanmar and Vietnam during 2017.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.155-155
• /
• 2017

The long grain rice varieties adaptable to South-east Asia tropical regions were tried to develop in Cambodian Agriculture Research and Development Institute (CARDI), Cambodia. The final goal is to develop rice varieties which can culture in diverse environmental conditions of tropical regions of South-east Asia under climate change. We collected and evaluated for agronomic traits of 131 rice germplasm from Cambodia, China, India, Indonesia, Myanmar, Philippines and Vietnam in CARDI. We selected core germplasm including leading varieties of target countries and made 813 F1 cross combinations between leading varieties of each country and promising germplasm of high yield potential, resistance to biotic/abiotic stresses, aromatic rice, and so on. Out of 607 F1s evaluated to heading date, plant type, agronomic traits, and grain type, 106 F1s selected and advanced to F2 populations. 106 F2 populations were evaluated to major agronomic traits, grain type and yield-component traits, and selected 2,560 plants in 62 F2 populations. During six seasons in 2014~2016, the lines of F3 subsequent-generation were cultured a total of 6,256 lines. In yield trial for promising lines in F5 generation, the growth duration from sowing to harvesting was 97~114 days. These lines were 88~129 in number of grain per panicle, an average of 84.6% in the range of 79.3~91.9% in the percentage of ripened grain and 17.5~22.8g in 1000-brown rice weight. The rough rice yields were in the range of 4.33~6.06 ton/ha with an average of 5.23 ton/ha. The yield was increased to 5~47% than Chulsa and 12~41% than IR66. Five lines, KR54-28-1, KR55-14-2, KR57-5-2, KR67-57-2 and KR128-19-1 were 5.33~6.06 ton/ha in rough rice yield. These high yield potential lines would be evaluated to adaptability in Cambodia, Laos, Myanmar and Vietnam during 2017.

• Korean Journal of Soil Science and Fertilizer
• /
• v.6 no.2
• /
• pp.95-105
• /
• 1973

Sink (grain)-filling rates of IR667 line (Suwon 213 and 214) and local leading varieties (Jinheung and Paldal) were investigated in relation to sink-source ratio, sink-source distance, forms of photosynthates, and weather factors. The results are as follows. 1. IR667 line have higher maximum filling rate (g. grain/day. ear) and shorter duration to reach maximum filling rate than local varieties. The curve pattern of sink-filling rate was high and steep type in IR667 line and low and broad type in local varieties. 2. Weather factors seem to give little effect on the curve pattern of sink-filling rate. 3. The functional sink-source distance (actual sink-source distance multiplied by the contribution rate of leaf for grain production) was shorter in upper leaves (flag and 2nd leaf) for IR667 line, the upper leaf-dependent type in grain production, and was longer in lower leaves (3rd and 4th) for local varieties, the lower leaf-dependent type. Specially short first internode from top may contribute to the upper leaf depencency of IR667 line. 4. According to free sugar-starch ratio (sugar/starch) in the culm and leaf sheath IR667 line could be classified as the high sugar type and the local varieties as the high starch type. The ratio of transportable form (sugar) to non transportable photosynthate (starch) seems to relate with sink-filling rate. And high sugar type is expected to have higher efficiency for grain production in view of energy balance. 5. A hypothesis that the higher in the uniformity within the series of productive structure the more efficient in grain production is proposed and discussed in relation to productivity. 6. According to the pattern of percent nutrient retention of each leaf blade IR667 showed the central retention type and Jinheung showed the apical retention type and each retention type appears to be a cause of each canopy conservation pattern. 7. From the content and percent distribution of nutrient in various organ IR667 could be classified as the leaf sheath dominant type and Jinheung as the leaf blade dominant type. 8. The fact that the greater the percent translocation of nutrient into grain the greater the percent nutrient retention in leaf blade was held between nitrogen and phosphorus within a variety and between varieties within a nutrient (N, P or K).

• Corrosion Science and Technology
• /
• v.17 no.2
• /
• pp.81-89
• /
• 2018

In this study, the effect of Nb alloying element on the corrosion fatigue properties of high strength steel is investigated by conducting fatigue experiments under corrosive condition and hydrogen induced condition, potentiodynamic polarization test, tensile test and surface analyses. Nb element is added to enhance the mechanical property of medium carbon steel. This element forms MX-type phases such as carbides and nitrides which are playing an important role in the grain refinement. The grain refinement is one of the effective way to improve mechanical property because both tensile strength and toughness can be improved at the same time. However, MX-type phase precipitates can be a susceptible site to localized corrosion in corrosive environment due to the potential difference between matrix and precipitate. The obtained results showed that Nb-added steel improved corrosion fatigue property by grain refinement. However, it is degraded for hydrogen-induced fatigue property due to Nb, Ti-inclusions acting as a stronger trap.

• Journal of Powder Materials
• /
• v.11 no.3
• /
• pp.233-241
• /
• 2004

In this study, bottom-up type powder processing and top-down type SPD (severe plastic deformation) approaches were combined in order to achieve both full density and grain refinement of Al-20 wt% Si powders without grain growth, which was considered as a bottle neck of the bottom-up method using the conventional powder metallurgy of compaction and sintering. ECAP (Equal channel angular pressing), one of the most promising method in SPD, was used for the powder consolidation. The powder ECAP processing with 1, 2, 4 and 8 passes was conducted for 10$0^{\circ}C$ and 20$0^{\circ}C$ It was found by microhardness, compression tests and micro-structure characterization that high mechanical strength could be achieved effectively as a result of the well bonded powder contact surface during ECAP process. The SPD processing of powders is a viable method to achieve both fully density and nanostructured materials.

• Korean Journal of Agricultural Science
• /
• v.44 no.3
• /
• pp.416-423
• /
• 2017

This study aimed to identify milling characteristics depending on the rotating speed of the main shaft of the cutting-type rice milling machine which can minimize the conventional milling process. Brown rice, which was produced in Gunsan-si, Jeollabuk-do, Republic of Korea, in 2016, was used as the experimental material. The milling characteristics of white rice were measured under four different rotating speeds of main shaft: 950 - 1,050 rpm, 1,000 - 1,100 rpm, 1,050 - 1,150 rpm, and 1,100 - 1,160 rpm. For each shaft speed, 300 kg of brown rice was processed, and the milling characteristics were measured according to the whiteness, grain temperature, cracked rice ratio, broken rice ratio, turbidity, and energy consumption. The whiteness of rice grain was found to be consistent at around $40{\pm}0.5$ only when milled at the shaft speed of 950 - 1,050 or 1,000 - 1,100 rpm. The grain temperature during the milling process increased by 11.35 to $11.85^{\circ}C$, showing little differences amongst shaft speeds. The cracked rice ratio increased by 8.2 to 10.4% at all conditions. The broken rice ratio ranged from 0.58 to 0.76%, reflecting a low level. The turbidity after milling was 54.8 ppm when milled at 1,000 - 1,100 rpm. Energy consumption of 12.98 and 12.18 kWh/ton were recorded at the shaft speed of 1,000 - 1,100 and 1,050 - 1,150 rpm, respectively. The result of this study indicates that the optimal rotating speed of main shaft would be 1,000 - 1,100 rpm for a cutting-type rice milling machine.