• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1337-1342
• /
• 2008

The whisker grows at the plating of a lead frame so that it causes the serious problem like the short. To prove this case, many people have studied the cause and influence of the tin whisker growth. This study explains the grain size affects the growth of the whisker in the lead frame. By these studies about the whisker, the whisker growth is discovered by stresses generated by the intermetallic compound and CTE mismatch in both plating and base metal. The stresses or lattice defect generated in the plating process changes grain structure of plating. Consequently, these various stresses are stabilized by forming unspecified whiskers through lots of grain boundaries. Because the grain boundary is the path of the whisker growth, the smaller grain size exists, the more whiskers grow.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.615-618
• /
• 2003

To investigate the electrical fire identification due to conductor structure analysis of an electrical wire, we are studied by temperature heating test, over current test, short test and electric molten marks. And metal structure analysis of wire by short, we are found out increase in crystal grain with heating temperature. Structure of specimen at over current 300[%] occurred hardly structure formation and boundary of grain.

• Journal of Biosystems Engineering
• /
• v.4 no.2
• /
• pp.32-45
• /
• 1979

The major objective of this study was to develope a computer simulation model to analyze drying process in a deep bed with natural air. The approach used to describe the continuous drying process in a deep bed was to divide the process into many small processes and simulate them by consecutively calculating the changes of grain and air conditions that occurred during short increment of time. Success criterion of the drying system was based on grain deterioration estimated by drymatter decomposition during drying. The results of the experimental test showed that the model satisfactory.

• Journal of Biosystems Engineering
• /
• v.8 no.2
• /
• pp.18-25
• /
• 1983

The binders introduced in Korea were originally designed to be used for Japonica varieties which have realtively long stem and are highly resistant to shattering. In order to use it for Tongil varieties which are short and easy to be shattered, mechanical modifications are necessary to reduce a grain loss incurred during its operation. This study was intended to investigate the binding unit, one of the major factors affecting grain losses. The binding parts of three binders used in Korea were analyzed and the grain loss was experimentally assessed for these binders. The results obtained from this study are summarized as follows: 1. From the motion analysis of discharge mechanism, the trajectory of the discharge arm appeared to be either circular or skewed elliptic. The velocity of a circular path mechanism was constant and smaller than that of a skewed elliptic path mechanism. The discharge grain loss of the former was about twice less than that of the latter. 2. It was found that the grain loss incurred due to the collision of the paddy bundles and ground was considerably high for Tongil varieties. The auxiliary discharge bar gave a significant influence on the motion and posture of the bundles, and the degree of impact on ground. 3. The installation of an auxiliary bar, which guides the paddy bundles smoothly to ground in order to reduce impact when the bundles fall down on ground, appeared to be very effective since the grain losses could be decreased by about 1.6 percentage point. However, the guide bar should be installed after some mechanical modification to reduce the velocity of discharge arm has been made.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1997.12a
• /
• pp.149-154
• /
• 1997

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1998.12a
• /
• pp.281-288
• /
• 1998

• Food Engineering Progress
• /
• v.15 no.4
• /
• pp.338-345
• /
• 2011

The pH, acidity, protein, color, reducing sugar, total sugar, alcohol and organoleptic characteristics of Takju containing 100% short grain rice (100 S), 100% long grain rice (100 L), 50 S+50% puffed rice powder (50 P) and 50 L+50 P were examined. After a drastic decrease during the initial stage of fermentation, the pH gradually increased except 100 L. Protein peaked at day 1 and decreased. A higher protein was noticed in puffed samples than in rice samples (p < 0.05). The Hunter "L" value decreased after a rise during the beginning of fermentation. Puffed samples showed higher reducing sugar than rice at day 0. Total sugar was similar to reducing sugar. A drastic increase in alcohol concentration was detected at day 2. Higher alcohol was observed in short grain than long grain and also in puffed samples than in rice (p < 0.05). A significant difference between 100 S and 100 L was observed in a sensory evaluation (p < 0.01); while no preference was detected.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.6
• /
• pp.523-526
• /
• 2006

When $GA_{4}$ was applied to heading stage, it was examined to understand the change of plant hormones and starch during grain filling and ripening. Exogenous gibberellin caused a dramatic decrease in endogenous ABA content. Endogenous $GA_{4}$ content in both superior and inferior part was more promoted in $GA_{4}-treated$ rice grain than in the control. $GA_{1}$ content of an inferior part was not detected in the control and $GA_{4}-treated$ rice otherwise $GA_{4}$ was detected in all grain parts. Ripened grain rate in $GA_{4}-treated$ rice grain was lower than that of the control plant. Amylopectin from $GA_{4}-treated$ grain contained more very short chains with degree of polymerization (DP) between 4 and 8 than amylopectin from the control plant. It suggests strongly that fine structure of rice endosperm may be changed by exogenously applied $GA_{4}$ in rice plants.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07b
• /
• pp.1270-1273
• /
• 2004

The combination of methane-chemical activation and Self-propagating High-temperature synthesis (SHS) has widened the possibilities for both methods. For YBCO systems the investigation showed that a short-term mechano-chemical activation of initial powders before SHS leads to single-phase and ultra-fine products. A new technique for preparation ultra-fine high-temperature superconductors of YBCO composition with a grain size d < $1{\mu}m$ is developed. The specific feature of the technique is formation of the $YBa_2Cu_3O_{7-x}$ crystalline lattice directly from an X-ray amorphous state arising as a result of mechanical activation of the original oxide mixture. The technique allows the stage of formation of any intermediate reaction products to be ruled out. X-ray and magnetic studies of ultra-fine high temperature superconductors (HTS) are carried out. Dimension effects associated with the microstructure peculiarities are revealed. A considerable enhancement of inter-grain critical currents is found to take place in the ultra-fine samples investigated.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.338-338
• /
• 2011

최근 FPD (Flat Pannel Display) 시장이 커짐에 따라 고효율, 저비용 제작 공정이 화두로 떠오르고 있다. ELA (Excimer Laser Annenling)을 이용한 LTPS (Low Temperature Poly Silicon) 공정은 mobility와 전류 점멸비 등에서 장점을 가지지만, 고비용, 대면적과 short-range에서 uniformity가 어렵다는 단점이 있다. 이를 극복하기 위한 방법으로 dLTA (diode Laser Thermal Annealing) 공정에 대한 연구가 진행되고 있다. 본 연구에서는 Flexible Display을 만들기 위한 방법으로 dLTA 공정을 진행하였다. 이 방법은 PI (Poly imide) 기판 위에 a-Si을 ICP CVD로 증착시킨 후, Diode Laser (980 nm)를 이용한 annealing을 통하여 a-Si이 poly-Si으로 결정화가 되는 것을 확인하였고, 에너지 조사량에 따른 grain boundary와 grain size을 통하여 비교 분석하였다. 실험 결과 ELA 공정을 이용한 것과 버금가는 실험 결과를 얻을 수 있었다.