An Analysis of the Warpage Phenomena of the Fiber-Reinforced Injection Molded Parts

Min, N 한국화학공학회 1997 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.35 No.4

토오크 양에 따른 세라믹 브라켓의 파절 저항성

한정흠,장민희,임용규,이동렬 대한치과교정학회 2007 대한치과교정학회지 Vol.37 No.4

심미 브라켓의 종류와 브라켓-호선 각도에 따른 마찰 저항에 대한 연구

제영지,장민희,임용규,이동렬 대한치과교정학회 2007 대한치과교정학회지 Vol.37 No.5

본 실험은 마찰력을 줄이고 물리적 성질을 개선하여 최근에 개발된 수 종의 심미 브라켓들과 교정 탄선간에 발생하는 마찰력의 크기를 측정, 비교해 보고자 하였다. 일반 슬롯의 세라믹 브라켓인 Inspire, Signature III와 Cristaline V, 스테인레스 스틸 (SS) 슬롯을 가진 세라믹 브라켓인 Clarity, 골드 슬롯을 가진 Luxi II, Polyoxymethylene 계열의 플라스틱 브라켓인 Brillant, SS 슬롯을 가진 컴파짓 브라켓인 Spirit MB, 금속 브라켓인 Integra를 사용하여 018″ 원형의 교정 탄선에 0˚, 4˚, 8˚의 tip angulation을 부여하고 elastic module로 결찰한 뒤 인공 타액 상태에서 활주이동할 때의 운동 마찰력을 측정하였다. 연구 결과 슬롯에 silica 처리된 세라믹 브라켓 (CR)이 유의하게 낮은 마찰력을 보였고 (P < 0.05), 단결정 세라믹 브라켓이 (IN) 유의하게 큰 마찰력을 보였다 (P < 0.05). 플라스틱 브라켓인 polyoxymethylene계열의 BR이 낮은 마찰력 양상을 보였고 이는 금속 브라켓과 유사하였다. 모든 브라켓에서 브라켓-탄선 각도가 증가함에 따라 유의하게 마찰력이 증가하였으나 주사전자현미경상에서 탄선이나 브라켓에 손상은 발견되지 않았다. 마찰력의 양상이 브라켓의 재질로 추측할 수 있는 것과는 다르게 나타난 결과로 보건대 심미 브라켓이 스테인레스 스틸 브라켓에 비해 마찰력 면에서는 오히려 우수하거나 큰 차이가 없으므로 임상적으로는 마찰력은 크게 고려하지 않아도 되겠다. Objective: The purpose of this study was to evaluate how the friction that occurs during the sliding movement of the archwire through esthetic brackets is differently affected by bracket materials, slot designs, and tip angulations of the archwire. Methods: Eight types of brackets with 0.018 inch slots (composite: Brillant (BR); composite with metal slot: Spirit MB (SP); ceramic: Inspire (IN), Signature (SI), Cristaline V (CR); ceramic with metal slot: Clarity (CL), Luxi II (LU); and metal bracket: Integra (IT)), and placed into groups of 20 brackets in each group, were tested in artificial saliva with 0.018 inch stainless steel wire. The wire tip angulations were given as 0, 4 and 8 degrees. Results: CR group significantly showed the lowest frictional force with all wire tip angulations of 0, 4, and 8 degrees. IN significantly showed the highest frictional force (P < 0.001). BR (Polyoxymethylene) had significantly less frictional force than SP (Polycarbonate) (P < 0.001) and showed no significant difference between metal brackets. Friction was increased as the wire tip angulations were increased, but no notches were observed on any parts of the archwire. Conclusions : According to the results of this study, esthetic brackets are superior or similar to SS brackets from a frictional point of view.

Research Papers : Natural Science ; Assessment of Genetic Diversity in Meedon Rice (Oryza sativa L) Germplasm

( Minn San Thein ),( Gi An Lee ),( Kyu Taek Cho ),( Jung Suk Sung ),( Jong Wook Jeong ),( Jong Hyun Park ),( Hyung Jin Baek ) 한국국제농업개발학회 2012 韓國國際農業開發學會誌 Vol.24 No.2

Meedon rice varieties are important for local adaptability, grain quality and market availability, and have been grown in Myanmar for centuries. Because of temporal variability and spatial heterogeneity, Meedon rice varieties in rainfed lowland areas may be diverse. However, information on diversity of Meedon rice germplasm is limited. This study was carried out to assess genetic diversity and to analyze population structure of Meedon rice germplasm conserved in Myanmar Seed Bank using SSR markers. For assessing genetic diversity, 154 accessions of Meedon rice germplasm were analyzed with nine SSR markers. A total of 86 alleles were detected with an average of 9.6 alleles per locus. All the loci were found to be polymorphic, and there were considerable genetic variation among accessions with mean values of expected heterozygosity (HE) = 0.5774 and polymorphic information content (PIC) = 0.5496. High frequency of rare alleles was identified, among which 35 unique (accession-specific) alleles were observed. Based on cluster analysis, rice accessions were mainly clustered into two groups, and as a result of model-based analysis, two distinct genetic populations and an admixture were classified. This result indicated that SSR markers have proved to be useful markers for detecting genetic diversity in Meedon rice, and the occurrence of a considerably high number of rare and unique alleles in the germplasm indicates their potentiality as a reservoir of rare genotypes for use. Unique alleles are also important because they may be diagnostic of a particular type of genotype for identification.

DISTRIBUTION AND KINEMATICS OF FORMALDEHYDE IN DARK CLOUDS IN M17 AND NGC 2024

MINN Y. K.,LEE Y. B. The Korean Astronomical Society 1994 Journal of The Korean Astronomical Society Vol.27 No.1

The 4.8GHz formaldehyde absorption line in the dark clouds in M17 and NGC 2024 regions has been mapped. In both nebulae, we detected two $H_2CO$ line components. In M17, the 24km $S^{-1}$ cloud is closely associated with the HII region located in front of the radio continuum source, and the 19km $S^{-1}$ cloud is associated with the visual dark clouds with a larger extent which are closer to us. The 19km $S^{-1}$ cloud has a mass motion approaching to the HII region. In both clouds, a velocity gradient from the north-east to the south-west directions is observed. The linewidth has no variation indicating no collapsing motion. In NGC 2024, the 9km $S^{-1}$ feature is extended along the dark bar in front of the bright nebula and a weak second component at 13km $S^{-1}$ is confined to the immediate vicinity of the radio source. Indications are that the 9km $S^{-1}$ cloud is physically associated with the dark bar and the 13km $S^{-1}$ cloud is located behind the radio source. The angular extent, the column density, and the total mass of the clouds are derived. The radial velocities of other molecular lines observed in these clouds are compared.

THE RELATION BETWEEN MOLECULE AND VISUAL EXTINCTION IN DARK CLOUDS

Minn, Y.K. The Korean Astronomical Society 1991 Journal of The Korean Astronomical Society Vol.24 No.2

We have compared the column densities of $H_2CO$, $^{13}CO$, $C^{18}O$, $^{12}CO$, CS, and $HCO^+$ to the visual extinctions derived from star counts in eight dark clouds, L1317, B1, L1551, L1535, L1544, L134, L134N, and B335. We examined the degree of correlation between molecules and extinctions. The contours of $^{13}CO$, $H_2CO$, and CS distributions show an excellent coincidence with those of the visual extinction. Even though the plots of molecule brightness temperature or column density as a function of the visual extinction show a considerable scatter, a good correlation is found between the two quantities. The turnover of the ratios of $^{13}CO$ and $H_2CO$ column densities to the visual extinction at high extinctions observed in several clouds is not apparent in this work. The ratios seem to maintain constant values within the range of $A_V$ we studied. The slopes of the relations between the molecule column density and extinction, and the threshold values of extinction for detection of molecules are comparable to the other works. The cause of the slope difference is discussed. We derived, for the first time, the relations of CS and $HCO^+$ column densities and the visual extinction. The ratio of CS column density to extinction is at least two orders of magnitude lower than the mean value for $^{13}CO$, but the threshold for detection of CS is comparable to that of $^{13}CO$. The ratio of the $HCO^+$ column density to extinction is one to two orders of magnitude lower than the mean ratio for $H_2CO$.

MicroRNA-200 family members and ZEB2 are associated with brain metastasis in gastric adenocarcinoma

MINN, YANG-KI,LEE, DA HYE,HYUNG, WOO JIN,KIM, JI EUN,CHOI, JUNJEONG,YANG, SEUNG-HO,SONG, HOTAEK,LIM, BEOM JIN,KIM, SE HOON Spandidos Publications 2014 International journal of oncology Vol.45 No.6

<P>Although the incidence of brain metastasis in gastric cancer is relatively low, its prevalence may increase with improved therapy and longer survival tumors. The molecular mechanisms underlying brain metastases are not well understood. To gain insight into the mechanism of brain metastasis, we studied differences in microRNA (miRNA) expression levels in 8 cases of matched primary gastric adenocarcinoma and brain metastatic adenocarcinoma using the Illumina microRNA microarray chip. We identified 6 upregulated and 2 downregulated miRNAs in all 8 cases simultaneously. Interestingly, 2 out of 8 miRNAs (hsa-miR?141-3p and hsa-miR-200b-3p) belonged to the miR-200 family. Online microRNA database searching revealed that ZEB2 is the top-ranked target gene for hsa-miR141-3p and hsa-miR-200b-3p, prompting us to focus ZEB2 expression in brain metastatic adenocarcinoma. We confirmed that ZEB2 expression was markedly downregulated in some brain metastatic samples. In addition, decreased ZEB2 expression was noted by western blot analysis of 2 metastatic gastric adenocarcinoma cell types that were derived by in vivo selection following intracardiac injection of gastric cancer cell lines. In conclusion, we demonstrate that expression of miRNA-200 family members and ZEB2 are associated with brain metastases of gastric adenocarcinoma, not only in matched patient samples, but also in metastatic cell lines that were derived by in vivo selection.</P>

Lagrangian and Hamiltonian in quantum field theory.

Minn, Jooha 목포대학교 기초과학연구소 2000 基礎科學硏究誌 Vol.18 No.-

There is subtle difference between Lagrangian and Hamiltonian formalism. More precisely Lagrangian and Hamiltonian are not always convertible into each other without ambiguity. We will mainly discuss these matters with quantum field theory. There is the issue of imposing gauge fixing constraint before or after quantization. Why and how does this matter?

Global Theory of Einstein-Cartan Equations - Godel Universe with Torsion -

Minn, Ho-Kee The Korean Astronomical Society 1976 Journal of The Korean Astronomical Society Vol.9 No.1

Godel models of the universe filled with fluid are studied in the framework of the Einstein-Cartan theory of gravitation. It is assumed that the models admit a group of motions simply transitive on space-time. The combined effects of spin and rotation(vorticity) are studied with a particular attention to whether the held equations impose any restriction on alignement of spin direction (a polarized spin distribution). The solutions are found explicitly in a closed form, which show that spin components are vanishingly small except in the direction of z-axis (the compass of inertia) in which they can assume an arbitrary distribution.

Assessment of Genetic Diversity in Meedon Rice (Oryza sativa L.) Germplasm

Minn San Thein,Gi-An Lee,Kyu Taek Cho,Jung Suk Sung,Jong-Wook Jeong,Jong Hyun Park,Hyung Jin Baek 한국국제농업개발학회 2012 韓國國際農業開發學會誌 Vol.24 No.2

Meedon rice varieties are important for local adaptability, grain quality and market availability, and have been grown in Myanmar for centuries. Because of temporal variability and spatial heterogeneity, Meedon rice varieties in rainfed lowland areas may be diverse. However, information on diversity of Meedon rice germplasm is limited. This study was carried out to assess genetic diversity and to analyze population structure of Meedon rice germplasm conserved in Myanmar Seed Bank using SSR markers. For assessing genetic diversity, 154 accessions of Meedon rice germplasm were analyzed with nine SSR markers. A total of 86 alleles were detected with an average of 9.6 alleles per locus. All the loci were found to be polymorphic, and there were considerable genetic variation among accessions with mean values of expected heterozygosity (HE) = 0.5774 and polymorphic information content (PIC) = 0.5496. High frequency of rare alleles was identified, among which 35 unique (accession-specific) alleles were observed. Based on cluster analysis, rice accessions were mainly clustered into two groups, and as a result of model-based analysis, two distinct genetic populations and an admixture were classified. This result indicated that SSR markers have proved to be useful markers for detecting genetic diversity in Meedon rice, and the occurrence of a considerably high number of rare and unique alleles in the germplasm indicates their potentiality as a reservoir of rare genotypes for use. Unique alleles are also important because they may be diagnostic of a particular type of genotype for identification.