Mosbauer effect on fast neutron-irradiated reactor pressure vessel

HONG,C.Y.,YI,Y.G.,YHOU,Y.B.,KIM,H.S.,SHIN,Y.N. 동국대학교 자연과학연구원 1997 자연과학연구 논문집 Vol.2 No.-

To estimate the embrittlement of the nuclear reactor pressure vessel, we have studied the change of the material property of RPV steel irradiated by fast neutrons (E??〉1MeV) leveled of 0∼10??n/㎠. After XRD experiment of all specimens, the influence of neutron irradiation on of RPV steel was studied by Mossbauer effect. The isomer shift and quadrupole splitting in site 3 were increased over the dose 10??n/㎠. But the magnetic hyperfine field was varied within ±3%.

자유드로잉 제품과 패드를 설치한 드로잉 제품의 특성

고관영,명노훈,하종성,이창수,최창권,최병용,허기영,김광수,김동수,장종훈,장윤철,김세환,오정민,하민정,박향자 울산과학대학 2000 연구논문집 Vol.27 No.1

본 연구는 자체 제작한 전체 패드가 부착된 드로잉 금형을 이용하여 SUS, 연강, AI, 6:4황동 판재를 드로잉 가공하여 생산된 제품의 특성을 자유드로잉 하여 얻은 제품의 특성과 비교 분석하였다. SUS 판재의 경우 제품에 발생하는 현상은 벽 주름, 구변주름, 수직 파단, 드로잉상처, 이어링이 발생하였으며 길이변화는 펀치어깨부분에서 가장 많이 늘어남을 볼 수 있었고 벽 주름 부분에 있어서 접혀진 부분은 상대적으로 적게 늘어남을 볼 수 있었다. 연강 판재는 SUS 판재에서 보여준 현상을 나타내었으나 SUS 판재에 비해 수직 파단은 적게 일어난 반면 이어링이 더 크게 일어났다. AI 판재의 경우 수직 파단은 일어나지 않았으나 플랜지 주름과 밑면터짐이 발생하였다. 6:4황동의 경우는 전체패드의 AI 판재 드로잉에서와 같이 밑면터짐과 플랜지 주름의 발생이 일어났다.

Hairy and Enhancer of Split 6 (Hes6) Deficiency in Mouse Impairs Neuroblast Differentiation in Dentate Gyrus Without Affecting Cell Proliferation and Integration into Mature Neurons

Nam, S. M.,Kim, Y. N.,Kim, J. W.,Kyeong, D. S.,Lee, S. H.,Son, Y.,Shin, J. H.,Kim, J.,Yi, S. S.,Yoon, Y. S. Springer Science + Business Media 2016 Cellular and molecular neurobiology Vol.36 No.1

<P>Hes6 is a member of the hairy-enhancer of split homolog (Hes) family of transcription factors and interacts with other Hes family genes. During development, Hes genes are expressed in neural stem cells and progenitor cells. However, the role of Hes6 in adult hippocampal neurogenesis remains unclear. We therefore investigated the effects of Hes6 on adult hippocampal neurogenesis, by comparing Hes6 knockout and wild-type mice. To this end, we immunostained for markers of neural stem cells and progenitor cells (nestin), proliferating cells (Ki67), post-mitotic neuroblasts and immature neurons (doublecortin, DCX), mature neuronal cells (NeuN), and astrocyte (S100 beta). We also injected 5-bromo-2'-deoxyuridine (BrdU) to trace the fate of mitotic cells. Nestin- and Ki67-positive proliferating cells did now show any significant differences between wild and knockout groups. Hes6 knockout negatively affects neuroblast differentiation based on DCX immunohistochemistry. On the contrary, the ratio of the BrdU and NeuN double-positive cells did not show any significance, even though it was slightly higher in the knockout group. These results suggest that Hes6 is involved in the regulation of neuroblast differentiation during adult neurogenesis, but does not influence integration into mature neurons.</P>

Zircon U-Pb geochronological and Hf isotopic constraints on the Precambrian crustal evolution of the north-eastern Yeongnam Massif, Korea

Kim, N.,Cheong, C.s.,Yi, K.,Song, Y.S.,Park, K.H.,Geng, J.z.,Li, H.k. Elsevier Scientific Pub. Co., etc.] 2014 Precambrian research Vol.242 No.-

In situ U-Pb dating and Hf isotopic analyses were conducted on zircons extracted from Paleoproterozoic metasedimentary rocks and peraluminous (meta)granitoids in the north-eastern Yeongnam Massif, Korea. Combined with previous results, analyses from detrital zircons from the metasedimentary rocks yield a predominant age population of ca. 2.5Ga with subordinate clusters at ca. 2.7, 2.3, and 2.1Ga, and minor points older than 2.8Ga. The detrital zircons frequently have textureless rims that were overgrown at ca. 2.03-1.85Ga, indicating post-depositional thermal overprints associated with the intrusion of neighbouring granitoids and metamorphism. The (meta)granitoids are divided into three lithologic groups of banded or augen biotite gneisses (group I: Pyeonghae and Buncheon gneiss), massive cordierite or two mica granitic gneisses (group II: Icheonri and Hongjesa granitic gneiss), and a garnet-bearing leucogranite (group III: Imwon leucogranite). The best estimates of the timing of the emplacement of the first two groups are indistinguishable within their error ranges; 1980+/-22Ma (Pyeonghae gneiss), 1966+/-15Ma (Buncheon gneiss), 1985+/-14Ma (Icheonri granitic gneiss), and 1975+/-16Ma (Hongjesa granitic gneiss). The upper intercept discordia ages of ca. 1.86Ga indicated by the metamorphic overgrowth rims of zircons from the Buncheon gneiss and the Icheonri granitic gneiss agree with the emplacement age of the Imwon leucogranite (1867+/-6Ma). A close genetic link between the (meta)granitoids and metasedimentary rocks is demonstrated by the comparable age pattern of inherited zircon cores in the former with that of detrital zircons in the latter. The lower intercept ages of zircons indicate repeated Pb loss events in the Neoproterozoic to Paleozoic, although their exact tectonic meaning is still unclear. Most zircons have negative @?<SUB>Hf</SUB> values corresponding to two-stage Hf model ages (T<SUB>2DM</SUB>) from 3.4 to 2.7Ga, demonstrating Neoarchaean to Paleoproterozoic reworking of the Paleo- to Neoarchaean crust. Zircons from group I metagranitoids display a narrow T<SUB>2DM</SUB> range (2.74+/-0.09Ga). The Neoarchaean Hf model ages are also reduced by high-@?<SUB>Hf</SUB> zircons from the metasedimentary rocks and group II metagranitoids (T<SUB>2DM</SUB>=ca. 2.75Ga), and most zircons from the Imwon leucogranite (T<SUB>2DM</SUB>=2.62+/-0.06Ga). The protoliths of group I metagranitoids are considered to be I-type granites that was derived by infracrustal melting at depth. In contrast, the scattered Hf model ages of zircons from group II metagranitoids are suggestive of crystallisation from heterogeneous S-type magmas derived from the partial melting of supracrustal rocks. It is concluded that the Neoarchaean Era (ca. 2.75-2.62Ga) marks the most important stage of crustal formation in the north-eastern Yeongnam Massif. The Paleoproterozoic (ca. 2.50-1.98Ga) magmas from which the zircons crystallised were principally a product of crustal reworking. These Hf isotopic features generally match those reported for zircons from the North China Craton and the eastern part of the Cathaysia Block in the South China Craton, but the zircon ages determined here do not allow an indisputable correlation of the north-eastern Yeongnam Massif with Paleoproterozoic terranes in eastern China.

선택성장 내부채널 반도체 레이저 다이오드

안형수,양민,이삼녕,정종제 한국해양대학교 산업기술연구소 2002 연구논문집 Vol.19 No.-

The low threshold current and high power selectively inner-channeled laser (SIC LD) was fabricated and estimated by the selective growth using the low-pressure MOCVD (metal organic chemical vapor deposition) method. The minimum threshold currents in the CW (continuous waves) moes of 8.1mA (cavity=250μm) and 12.9mA (cavity=750μm) were achieved with a stabilized fundamental mode. We could obtain the maximum output powers with the uncoated facets of 100mW at pulsed width and 50mW at continuous waves condition in 250μm cavity length. SIC LD is index-guided laser which has new fabrication techniques different from ridge waveguide structure lasers.

종모돈의 정액성상, 동결-융해 후 정자의 생존성, 혈청 중 FSH, LH, Estradiol-17β 및 Testosterone 농도에 미치는 품종과 계절의 영향

박창식,성낙도,김철호,진동일,최양석,이영주 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

본 연구는 종모돈의 정액성상,동결-융해 후 정자의 생존성 그리고 혈청 중 FSH,LH,estradiol-17β 및 testosterone 농도에 미치는 품종과 계절의 영향을 조사하여 우수한 종모돈의 손발을 위한 기초자료를 얻고자 실시하였다. 요크셔 종이 듀록종보다 봄,여름,가을,겨울에서 정액량이 많았으며,정액농도에서는 차이가 없었다. 계절별 정액량은 듀록 및 요크셔종에서 봄철이 여름,가을 및 겨울철에 비하여 많았고,정자농도는 차이가 없었다. 듀록종과 요크셔종에서 각각 봄철에 생산한 정자가 여름,가을 및 겨울철에 생산한 정자보다 동결-융해 후 정자운동성 및 정상첨체 비율이 높았다. 한편 듀록종과 요크셔종에세 동결-융해 후 정자운동성은 모든 계절에서 요크셔종이 높게 냐타났으나,정상첨체에서는 차이가 없었다. 혈청 중 FSH의 농도를 비교한 결과 요크셔종이 듀록종보다 모든 계절에서 낮은 농도를 나타내었다. 그러나 두 품종 모두에서 각각 계절 간애 차이가 없었다. 혈청 중 LH와 estradiol-17β의 농도를 비교한 결과 요크셔종과 듀록종 간에 차이가 없었다. 또한 두 품종 모두에서 계절 간에 차이가 없었다. 종모돈의 품종별,계절별 혈청 중 testosterone의 농도를 비교한 결과 요크셔종이 듀록종보다 모든 계절에서 높게 나타났다. 또한 두 품종 모두에서 각각 봄철이 여름,가을 및 겨울철에 벼하여 혈청 중 testosterone의 농도가 높은 것으로 나타났다. 이상의 결과를 종합하여 보면,FSH의 농도가 낮을수록 정액생산량이 높은 것으로 나타났으며,혈청 중 testosterone의 농도가 높을수록 동결-융해 정자의 운동성 및 정상첨체의 비율이 높은 것으로 나타났다. This study was carried out to investigate. the effects of semen characteristics, frozen-thawed sperm viability and serum FSH, LH, estradiol-l7β and testosterone concentrations between breeds and among seasons in boars. In all seasons, Yorkshire boars produced higher semen volume compared with Duroc boars, whereas sperm concentration did not differ significantly between Duroc and Yorkshire boars. Semen volume in spring was higher compared with summer, autumn and winter in both Duroc, and Yorkshire boars, but sperm concentration did not differ significantly among seasons. Sperm motility and normal acrosome rate of frozen-thawed sperm produced in spring were higher than those in summer, autumn and winter in both Duroc and Yorkshire boars. Sperm motility of frozen-thawed sperm in Yorkshire boars was higher than that in Duroc boars regardless of seasons. However, normal acrosome rate did not differ significantly between Duroc and Yorkshire boars. Serum FSH concentration in Yorkshire boars was lower than that in Duroc boars in all seasons. However, there were no significant differences on serum FSH concentration of Duroc and Yorkshire boars among seasons. Serum LH and estradiol-l7β concentrations did not differ significantly between Duroc and Yorlcshire boars. Also, there were no significant differences in serum LH and estradiol-l7β concentrations of Duroc and Yorkshire boars among seasons. Serum testosterone concentration in Yorkshire boars was higher than that in Duroc boars in all seasons. In both breeds, serum testosterone concentrations were higher in spring than in summer, autumn and winter. In conclusion, when serum FSH concentrations were low, semen volumes were high, and when serum testosterone concentrations were high, sperm motility and normal acrosome rate of frozen-thawed sperm were high.

헬리콥터 로터 블레이드 제빙시스템 설계를 위한 블레이드 제빙해석 기법 연구

박남은(N.E. Park),우철훈(C.H. Woo),이석준(S.J. Yee),이재복(J.B. Yi),임태균(T.G. Lim) 한국전산유체공학회 2013 한국전산유체공학회 학술대회논문집 Vol.2013 No.5

When the helicopter is flighting through icing condition, the ice could be accreted on fuselage and blades. The ice on blade could deform the blade configuration and increase the weight of blade. The unstable motions of blade make decreasing of performance, handling quality and structural stability due to the abnormal weight increase and configuration change. The helicopter deicing system is required to avoid risk by icing. Generally, the engine intake and the pitot sensor are adapted anti-icing system, but the rotor blade uses deicing system because the large size heater mat of blade needs a lot of power consumption. The anti-icing system is always active heater mat in icing condition; the deicing system is run alternately by on/off time sequence to avoid ice accretion on blade. Especially, due to the composite blade is weak by heat, over heat could make weak brittleness of blade. Thus, the de-icing system should be designed not only eliminate the ice on leading edge but also not damage the blade by heat source. First of all, the icing region estimation on blade is needed to design of rotor blade deicing system. In this paper, air flow field and multi-phase fluid analysis was performed by the commercial CFD s/w, SC/Tetra to calculate the collection efficiency around objects. The ice accretion analysis was performed by developed in-house code, ASTROD based on Messinger thermodynamic model. The computation result shows good estimations of icing region and ice thickness. In this study, de-icing situation is simplified that the blade surface adjoin with ice and thermal conduction occur at that interface. To analysis of convection on exterior surface of ice and internal heat power from heater mat by numerical method, discrete computational nodes of ice covered blade and consider phase change at the interface blade and ice. The numerical analysis result compared with ice wind tunnel test data of the blade to evaluate. The numerical method results show similar with experimental data about time to eliminate the ice and temperature of off-time range.

남녀 대학생의 신체만족도, 자아존중감과 우울에 대한 비교연구

김나영,김민정,김진경,박민주,박민지,이다솜,이민경,이지영,전양지,정하은 이화여자대학교 간호과학대학 2010 이화간호학회지 Vol.- No.44

The purpose of this study was to know relationship among body image and self esteem, depression obtained from male and female. Also we wanted to know what is differences between male and female groups. We intended to provide basis materials for developing programs to increase body image, self esteem and to decrease depression at the same time. Object of our study were male and female who are in collage. There were 90 people in each group. We used frequency analysis to know general characteristics, and we use frequency analysis and descriptive statistic analysis to know question distribution. We studied relationship among body image and self esteem and depression with using Spearman Correlation and analysised the differences between male and female groups with using T-test. This is the result of our research. 1. ale show higher BCS and BET scores than women. Between male and female, self-esteem have no big differences. And female is more depressive than male. 2. he two elements that body image and depression are in inverse proportion to each other in both male and female university students. 3. The two elements that self-esteem and depression are in inverse proportion to each other in both male and female university students. 4. The two elements that body image and self-esteem are in inverse proportion to each other in both male and female university students. And male have high correlation between BCS and BET, BCS and self-esteem, self-esteem and depression tha female. On the other hand, female have high correlation between BET and self-esteem, BET and depression In short, both male and female have correlation between body image, self-esteem and depression. Especially, between self-esteem snd depression have high correlation. In body image, especially female have high correlation between BET and depression. Finally we found the fact that female is more sensitively react than male about appearance.

The SAURON project – XIII. SAURON–GALEX study of early-type galaxies: the ultraviolet colour–magnitude relations and Fundamental Planes

Jeong, Hyunjin,Yi, Sukyoung K.,Bureau, Martin,Davies, Roger L.,Falcó,n-Barroso, Jesú,s,van de Ven, Glenn,Peletier, Reynier F.,Bacon, Roland,Cappellari, Michele,de Zeeuw, Tim,Emsellem, Eric Blackwell Publishing Ltd 2009 Monthly notices of the Royal Astronomical Society Vol.398 No.4

<P>ABSTRACT</P><P>We present <I>Galaxy Evolution Explorer</I> far-ultraviolet (FUV) and near-ultraviolet (NUV) imaging of 34 nearby early-type galaxies from the SAURON representative sample of 48 E/S0 galaxies, all of which have ground-based optical imaging from the MDM Observatory. The surface brightness profiles of nine galaxies (≈26 per cent) show regions with blue UV−optical colours suggesting RSF. Five of these (≈15 per cent) show blue integrated UV–optical colours that set them aside in the NUV integrated colour–magnitude relation. These are objects with either exceptionally intense and localized NUV fluxes or blue UV−optical colours throughout. They also have other properties confirming they have had RSF, in particular Hβ absorption higher than expected for a quiescent population and a higher CO detection rate. This suggests that residual star formation is more common in early-type galaxies than we are used to believe. NUV blue galaxies are generally drawn from the lower stellar velocity dispersion (σ<SUB>e</SUB> < 200 km s<SUP>−1</SUP>) and thus lower dynamical mass part of the sample. We have also constructed the first UV Fundamental Planes and show that NUV blue galaxies bias the slopes and increase the scatters. If they are eliminated, the fits get closer to expectations from the virial theorem. Although our analysis is based on a limited sample, it seems that a dominant fraction of the tilt and scatter of the UV Fundamental Planes is due to the presence of young stars in preferentially low-mass early-type galaxies. Interestingly, the UV–optical radial colour profiles reveal a variety of behaviours, with many galaxies showing signs of RSF, a central UV-upturn phenomenon, smooth but large-scale age and metallicity gradients and in many cases a combination of these. In addition, FUV−NUV and FUV−<I>V</I> colours even bluer than those normally associated with UV-upturn galaxies are observed at the centre of some quiescent galaxies. Four out of the five UV-upturn galaxies are slow rotators. These objects should thus pose interesting challenges to stellar evolutionary models of the UV upturn.</P>

Improved Hydrogen Capping Effect in n-Type Crystalline Silicon Solar Cells by SiN(Si-Rich)/SiN(N-Rich) Stacked Passivation

Choi, J.,Balaji, N.,Dao, V. A.,Park, C.,Lee, S.,Kim, J.,Ju, M.,Lee, H.,Lee, Y. J.,Yi, J. Springer Science + Business Media 2014 Journal of electronic materials Vol.43 No.9