Matal bearing의 壓撥熔接의 關한 硏究

오남석,민택기 충남대학교 1991 論文集 Vol.14 No.1

In this study, to find out optimum condition of friction welding when we weld together bushing part and flange by friction with Water and air ejected into bushing at a fixed pressure of 6[㎏f/㎠], the experiment was performed with metal bearing. Heating pressure was changed from 1.6[㎏f/㎟], to 2.0, 2.4, 2.8, 3.0, and 3.2 on the fixed condition that spindle speed is 1600[rpm], preheating pressure 0.6[㎏f/㎟], upset pressure 2.6[㎏f/㎟], preheating time 0.5 seconds, heating time 1.7 seconds, upset time 2.0 seconds. On the basis of the experimental results, the following conculusion are drawn : A. Tensile strength shows the maximum 42[㎏f/㎟] without rising of Al-alloy structure when heating pressure is between 2.4[㎏f/㎟] and 2.8[㎏f/㎟] B. Bending strength under 2.8[㎏f/㎟] heating pressure is shown 37.2[㎏f/㎟], which is a little lower than base metal and is the maximum on the condition that there is no rising of the Al-alloy structure. C. Hardness is the maximum 275[Hv] at the friction weld interface. Heat-affected zone where hardness is higher than base metal spreads 1.5[㎜] far from the friction weld interface in the bushing part and 2.5[㎜] in the flange part. D. Heat-affected zone of Al-alloy structure inside of bushing part was not changed by heating pressure, but the Al-alloy structure wthin 2.0[㎜] from the friction weld interface changed.

이종재료의 레이저용접에서 잔류응력 평가

오세헌,민택기 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.3

Generally, it is used the compensation spring to compensate the inaccuracy of screen image induced by thermal deformation in CRT monitor. Its mechanism is bi-metallic system made of heterogeneous metals and these is bonded by laser welding. But laser welding induces the non-uniform temperature distribution and locally residual stress is yielded by these temperature deviation. This paper studies residual stress of laser weldment using FEA and hole drilling method. The results are followed. In the case of heterogeneous materials weldment, higher residual stress induced in the weldment region of SUS 304 which have larger CTE than Xi 36 and residual stress on the middle of specimen is higher by 10.9% than that of its surface Measured residual stress of SUS 304 yield 481MPa and that of Ni 36 is 140.5MPa in the vicinity of the welding region. And the residual distribution is very similar in comparison with FEA result.

양극성 기분장애에서 세로토닌 수용체 유전자의 다형성(102T/C)에 관하여

지익성,신석철,왕성근,이선우,신용재,김충수,김상국,최하석,오승용,류택근,이영호 대한생물치료정신의학회 1999 생물치료정신의학 Vol.5 No.2

Compensatory induction of the TRPV6 channel in a calbindin-D9k knockout mouse: Its regulation by 1,25-hydroxyvitamin D₃

Lee, Geun-Shik,Jung, Eui-Man,Choi, Kyung-Chul,Oh, Goo Taeg,Jeung, Eui-Bae Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of cellular biochemistry Vol.108 No.5

<P>Active calcium transport is carried out by calcium channel proteins, cytosolic buffering or transfer proteins, and pump proteins. Several components of this transport system have recently been verified using gene knockout (KO) models. We previously generated calbindin-D9k (CaBP-9k) KO mice and reported that induction of expression of some calcium transport proteins can compensate for the CaBP-9k gene deficiency. In the current study, we have further clarified the compensatory regulation of calcium transport genes by two calcium regulating hormones, 1,25-dihydroxyvitamin D<SUB>3</SUB> (1,25(OH)<SUB>2</SUB>D<SUB>3</SUB>) and parathyroid hormone (PTH), in CaBP-9k KO mice, because the levels of these hormones differ between the KO and wild-type (WT) mice. The induction of transient receptor potential cation channel, subfamily V, member 6 (TRPV6) in the duodenum was observed in adult KO male mice but induction was not modified by physiologic doses of 1,25(OH)<SUB>2</SUB>D<SUB>3</SUB>. Duodenal TRPV6 transcription in WT and female KO mice were modulated by 1,25(OH)<SUB>2</SUB>D<SUB>3</SUB> in a dose-dependent manner. This compensatory gene induction was not detected in the mice fed a vitamin D<SUB>3</SUB>-deficient diet. Compensatory gene induction was not affected by PTH. Thus, the compensatory expression of duodenal TRPV6 in the KO male mice may be tightly correlated with serum 1,25(OH)<SUB>2</SUB>D<SUB>3</SUB>. Vitamin D receptor (VDR) transcription and protein levels were measured to examine whether VDR expression mediates differential regulation of duodenal TRPV6 between WT and KO mice, but expression and levels of VDR were similar in both genotypes. The compensatory TRPV6 transcripts in KO mice may be modulated by endogenous vitamin D<SUB>3</SUB> via other factors of VDR signaling complexes. J. Cell. Biochem. 108: 1175–1183, 2009. © 2009 Wiley-Liss, Inc.</P>

Induced Mutant Animal Models for Studying the Genetics of Hypertension and Atherosclerosis

Oh, Goo-Taeg The Korean Society of Toxicology Korea Environment 2001 Toxicological Research Vol.17 No.-

Gene targeting allows precise, predetermined changes to be made in a chosen gene in the mouse genome. To date, targeting has been used most often for generation of animals completely lacking the product of a gene of interest. Models of essential hypertension have been produced by mutated genes relating renin angiotensin system. The most significant contribution to understanding the genetic etiology of essential hypertension is probably the demonstration that discrete alterations in the expression of a variety of different genes can individually cause changes in the blood pressures of mice, even when the mice have all their compensatory mechanisms intact. These effects are readily detected in animals having moderate decreases in gene function due to heterozygosity for gene disruptions or modest increases due to gene duplication. As a species the mouse is highly resistant to atherosclerosis. However. through induced mutations it has been possible to develop lines oj mice that are deficient in apolipoprotein E, a ligand important in lipoprotein clearance, develop atherosclerotic lesions resembling those observed in humans. The atherosclerotic lesions in apoE-deficient mice have been well characterized, and they resemble human lesions in their sites of predilection and progression to the fibroproliferative stage. Other promising models are mice that are deficient in the low-density lipoprotein receptor. Considerable work still remains to be done in dissecting out in a rigorous manner the effects of alterations in single genes on the induction or progression of atherosclerosis and on the control of blood pressures. Perhaps even more exciting is the opportunity now becoming available to breed animals in which the effects oj precise differences in more than one gene can be studied in combination.

Species Composition and Seasonal Variations of the Shrimp Beam Trawl Fisheries i

Oh, Taeg-Yun 부경대학교 수산과학연구소 2004 硏究業績集 Vol.28 No.-

Primary Culture of Human Hepatocytes from Small Size Sample

Oh, Goo-Taeg,Ahn, Chang-Joon,Ahn, Byung-Min,Hyun, Byung-Hwa,Choi, Jae-Yoon,Kim, Hwan-Mook The Korean Society of Toxicology Korea Environment 1992 Toxicological Research Vol.8 No.2

Human and rat hepatocytes were isolated by nonperfusion method and cultured for longer than 5 days. Human liver biopsy sample and rat liver were used as hepatocyte source. Several physical and chemical factors which were influencing on hepatocyte isolation procedure were examined and a batch isolation procedure was established for small size sample of rat liver. Isolated hepatocytes showed normal morphlologica characteristics in microscopy and electron microscopical examinations and a morphologica response to phalloidin. Isolated cells were cultured as a monolayer and proven to have intact morphological characteristics for longer than 15 days. Because human liver sample is harder and tighter compared with rat liver, a standard procedure for rat hepatocytes was slightly modified to reduce mechanical damage. Similarly with rat hepatocytes, isolated human hepatocytes showed a normal morphological characteristics and could be cultured for longer than 15days. Human and rat hepatocytes were examined on their functional integrities including cytochrome-P450 related enzyme activity and it's inducibility, hormonal inducibility of AIB uptake and TAT activity, albumin synthesis, DNA synthesis, cellular protein maintenance. In all parameters used in the present study, human and rat hepatocytes showed normal functional characteristics.

Hematein Inhibits Tumor Necrotic Factor - 2 a - Induced Vascular Cell Adhesion Molecule - 1 and nuclear factor - κB Dependent gene Expression in Human Vascular Endothelial cells

Oh,Goo Taeg,Jeong,Tae Sook,Hong,Jung Joo 한국지질학회 2001 韓國脂質學會誌 Vol.11 No.1

Purification and crystal growth of NPB via imidazolium based ionic liquids

Oh, Yong-Taeg,Shin, Dong-Chan Elsevier 2018 Journal of crystal growth Vol.487 No.-

<P><B>Abstract</B></P> <P>Here we report the production of high purity and crystallinity organic electronic material of NPB (<I>N,N</I>′-Di-[(1-naphthyl)-<I>N,N</I>′-diphenyl]-1,1′-biphenyl-4,4′-diamine (C<SUB>44</SUB>H<SUB>32</SUB>N<SUB>2</SUB>) through solution recrystallization within imidazolium based ionic liquids. When low purity NPB was recrystallized at 170 °C within C<SUB>8</SUB>MIM[TFSI], its purity was drastically improved from 82% to 99.92%. These recrystallized NPB crystals showed 0.040° FWHM (Full Width Half Maximum) of X-ray (1 1 1) diffraction peak. Such small FWHM angle indicates single-crystal like crystallinity. Initial NPB powder was dissolved at 100 °C and recrystallized at temperature above 110 °C. At higher temperature of 170 °C, a small number of bigger crystals were formed compared to those at 110 °C. This can be well explained by the classical nucleation and growth theory. Therefore, solution recrystallization process using ionic liquid might be promising for mass production of organic electronic materials by replacing the widely-used sublimation purification method.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High quality NPB can be obtained through solution recrystallization. </LI> <LI> The purity of NPB was improved from 82% to 99.92% within C<SUB>8</SUB>MIM[TFSI]. </LI> <LI> The recrystallized NPB crystal has single-crystal like crystallinity. </LI> </UL> </P>

The Population Genetic Structure of the Japanese Anchovy (Engraulis japonicus Temminck & Schlegel) in the West, South and East Seas of Korea Based on Microsatellite DNA Analysis

Taeg Yun Oh(오택윤),Joo Il Kim(김주일),Young Il Seo(서영일),Eun Seob Cho(조은섭) 한국생명과학회 2009 생명과학회지 Vol.19 No.2

본 연구는 2006년 8월경에 어획된 서해, 남해 및 동해 멸치집단을 분석하기 위하여 6종류의 microsatellite로 하였다. 서해멸치의 경우, 샘플수 72마리에 대한 allele 범위가 19-41로 평균 28.5를 보였다. 특히 EJ9 locus에서 평균보다 약 1.4배 많은 41를 나타내었다. 남해멸치의 평균 allele는 24.5로 서해보다는 적었고, EJ2, EJ9, EJ27.1 loci는 평균보다 높은 29-37의 범위를 보였다. 동해멸치는 평균 allele가 25.0으로 EJ35를 제외하면 대부분의 loci에서 평균 이상을 보였다. 그러나 서해, 남해 및 동해멸치의 allele 빈도율은 대부분 0.24 이하로 나타났다. 또한 Hobs보다 Hexp에서 0.5 정도 높은 값을 보였으나 유의성은 없었다(p>0.05). 유전적 다양성도 0.9 이상으로 매우 높은 값을 보였다. 6종류의 microsatellite에 대한 지역간의 유전적 차이 및 거리는 0.258과 0.019로 유의적으로 차이는 없었다(p>0.05). 따라서 서해, 남해 및 동해 멸치계군은 유전적으로 동일한 집단을 형성하고 있는 것으로 판단된다. The characteristics of the population genetic structure of the Japanese anchovy (Engraulis japonicus Temminck & Schlegel) were collected from the West, South and East Seas of Korea in August, 2006 and were compared using six microsatellite DNA loci. In the West Sea population, the range of allele number against 72 individuals was from 19 to 41, the average allele number was 28.5. In EJ9, the allele number had the highest value of 41, this was 1.4 times higher than the average number of allele. The average allele number of the South Sea population was 24.5 that was less than that of West Sea population. In EJ2, EJ9 and EJ27.1 loci, the allele number was higher than average allele number in the South Sea population. In the East Sea population, the average allele number was estimated at 25.0 that most of loci except for EJ35 were higher than average allele number. Allele frequency in the West, South and East Sea populations was below 0.24. The value of observed heterozosity for six loci was approximately 0.5 higher than that of expected heterozosity (p>0.05), but three populations similar values to these heterozosity. Although the genetic diversity was higher value of above 0.9, three populations had a similar value. Genetic differentiation and distance combined estimate of the six loci were 0.258 and 0.019 (p>0.05), respectively, but showed no significant distance between three populations. These results suggested that it is responsible for no differentiated gene pool between three populations.