• Journal of Animal Science and Technology
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• v.44 no.6
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• pp.701-710
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• 2002

Studies on the Viability of In Vitro-Matured Bovine Oocytes Vitrified by Microdrop and Straw Method To establish vitrification method for bovine oocytes, mature bovine oocytes were vitrified by microdrop (MD) or straw (Straw) method and the viability of vitrified oocytes with or without cumulus cells (CC) were examined by several methods; a) parthenogenetic activation; b) pronuclear formation after in vitro fertilization (IVF); and c) embryonic development after IVF. The survival rate of vitrified oocytes by MD was significantly higher than by Straw (92.50 vs. 74.19%, p<0.05). Most of the oocytes survived from vitrification using the MD methods. Cleavage and blastocyst development of parthenogenetically activated oocytes were higher in MD (45.05% and 10.81%, respectively; p<0.05)) than those in Straw method (27.17% and 6.52%, respectively; p<0.05). Male and female pronuclear formation of vitrified-thawed oocytes with or without cumulus cells (CC) after IVF were examined, respectively. The survival rate of vitrified oocytes by MD without CC was no difference between MD and Straw (80.368.14% vs. 67.31%). Normal fertilization (2PN) rates were not different among groups (Fresh; 54.55% vs. MD; 42.22% vs. Straw; 37.14%, p>0.05). While no fertilization (<1PN) rates were significantly different between fresh and vitrified-thawed groups (Fresh; 32.47% vs. MD; 57.78% and Straw 62.86%, p<0.05). The polyspermy (3PN) was appeared in the fresh (12.99%), but no appeared in the vitrified-thawed groups. In the without CC, normal fertilization (2PN) rates were significantly different between fresh and vitrified-thawed oocytes (Fresh; 59.38% vs. MD; 17.31% and Straw; 30.43%, p<0.05). Moreover, no fertilization (<1PN) rates were significantly different between fresh and vitrified-thawed groups (Fresh; 23.44% vs. MD; 73.08% and Straw 58.70%, p<0.05). The polyspermy (3PN, >4PN) was appeared not only fresh but vitrified-thawed groups. After IVF, two-cell developmental rates of vitrified oocytes with CC by MD and Straw were significantly low compared to fresh oocytes (Fresh; 81.76% vs. MD; 22.22% and Straw; 11.36%, p<0.05). Blastocyst developmental rates of vitrified oocytes also were significantly low compared to fresh oocytes (Fresh; 28.38 vs. MD; 1.71% and Straw 0%, p<0.05). In the without CC, two-cell developmental rates were no difference between Fresh and MD (27.59% vs. 19.25%, p<0.05), while blastocyst rates were difference between Fresh and MD or Straw (4.31% vs. 0.62% and 0%, respectively; p<0.05). In conclusion, the results indicate that the vitrified bovine oocytes have the ability to develop to the blastocyst stage after IVF.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.65-65
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• 2010

pn 접합 소자는 반도체 소자의 매우 중요한 기본 구조이다. 최근 들어 나노선과 반도체 기판으로 구성된 pn 접합소자에 대한 연구가 활발히 진행되고 있으나, 나노선을 이용한 대부분의 접합소자는 나노선을 분산하여 소자를 제작하기 때문에 어레이 구조의 소자를 만들기에는 어려움이 있다. 본 연구에서는 성장된 나노선을 슬라이딩 전이하는 방법으로 정렬된 n-$SnO_2$ 나노선과 도핑이 된 p-Si 기판으로 이루어진 pn 접합 소자 어레이 구조를 제작하였다. 제작된 소자의 전류-전압 측정을 통해 정류 (rectification) 작용을 확인하였고 rectification ratio은 수천~수만으로 측정되었다. 소자에 UV (254nm) 빛을 조사하여 광전류의 증가를 확인할 수 있었다. 또한 소자에 15V이상의 전압을 걸어주면 접합 부분에서 EL(electroluminescence) 효과인 발광을 확인 할 수 있었다. 이처럼 나노선과 기판으로 구성된 pn 접합 소자는 다이오드, 태양전지 뿐 아니라 레이저와 LED등으로도 응용될 것으로 예상된다.

• Bulletin of the Korean Chemical Society
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• v.4 no.4
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• pp.180-183
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• 1983

The reaction of $IrClH_2(CO)(Ph_3P)_2$ ($Ph_3P$=triphenylphosphine) with acrylonitrile (AN) produces a stoichiometric amount of propionitrile (PN) at $100^{\circ}C$ under nitrogen, which suggests that the catalytic hydrogenation of AN to PN with $IrCl(CO)(Ph_3P)_2$ proceeds through the hydride route where the formation of the dihydrido complex, $IrClH_2(CO)(Ph_3P)_2$ is the initial step. The rate of the hydrogenation of AN to PN with $IrCl(CO)(Ph_3P)_2$ is decreased by the presence of excess $Cl^-$ in the reaction system, which suggests that $Cl^-$ is the dissociating ligand in the catalytic cycle. It has been also found that the rate of the hydrogenation increases with inercase both in hydrogen pressure and in concentration of free $Ph_3P$, and with decrease in AN concentration in the reaction system.

• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.162-167
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• 2013

An epitaxial layer structure for heterojunction p-InGaP/N-InAlGaP solar cell has proposed. Simulation for current density-voltage characteristics has been performed on p-InGaP/N-InAlGaP structure and the simulation results were compared with p-InGaP/p-GaAs/N-InAlGaP structure and homogeneous InGaP pn junction structure. The simulation result showed that the maximum output power and fill factor have greatly increased by replacing n-InGaP with N-InAlGaP. The thicknesses of p-InGaP and n-InAlGaP were optimized for the epitaxial layer structure of p-InGaP/N-InAlGaP.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.473-476
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• 1987

Low temperature phosphorus-nitride CVD was newly developed for a high quality gate insulator on InP substrate. This film showed the Poole-Frenkel type conduction in high electric field with resistivity higher than $1{\times}10^{14}$ ohm-cm near the electric field of $1{\times}10^7\;volt/cm$. The C-V hysteresis width was very small as 0.17 volt. The density of interface trap states was $2{\times}10^{11}cm^{-2}ev^{-1}$ below the conduction band edge of InP substrate. Effective electron mobility was about $1200-1500\;cm^2/Vsec$ and showed the instability of PN-InP MISFETs drain current reduced less than 10 percent for the period $0.5-10^3sec$.

• Journal of the Korean Mathematical Society
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• v.36 no.3
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• pp.633-648
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• 1999

In this paper, for any two bipartite ordered sets P and Q, we define the convolution P * Q of P and Q. For dim(P)=s and dim(Q)=t, we prove that s+t-(U+V)-2 dim(P*Q) s+t-(U+V)+2, where U+V is the max-mn integer of the certain realizers. In particular, we also prove that dim(P)=n+k- {{{{ { n+k} over {3 } }}}} for 2 k n<2k and dim(Pn ,k)=n for n 2k, where Pn,k=Sn*Sk is the convolution of two standard ordered sets Sn and Sk.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.123-128
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• 2003

This study was conducted to examine the water use efficiency (WUE) in five species of one-year-old seedlings grown in a field nursery in Mongolia. Larix sibirica and Pinus sylvestris are the most dominant coniferous species while Ulmus pumila is an important deciduous species known well-adapted in harsh conditions such as in semi-arid forests and Gobi desert regions. Caragana arborescens (Siberian pea shrub) and Hippophae rhamnoides are N-fixing shrubs in Mongolia. Thirty one-year-old seedlings were sampled from each of the five species (a total of 150 samples) and measured for net photosynthetic rate (Pn) and transpiration rate (E). The Pn and E were used to calculate and compare the WUE of each species. Pn differed significantly among the five species (p < 0.05). However, there was no significant difference in Pn between L. sibirica and H. rhamnoides (p > 0.05). C. arborescens showed the highest Pn whereas U. pumila did the poorest. E differed significantly among the five species (p < 0.05). L. sibirica and U. pumila showed considerably lower E than other species. Thus, WUE values of coniferous species such as L. sibirica and P. sylvestris were significantly greater than deciduous or shrub species such as U. pumila, C. arborescens and H. rhamnoides (p < 0.01). It may result that conifers showed relatively high water use efficiency than deciduous or shrub trees due to their lower transpiration rates, which resulted in morphological and physiological characteristics of their leaves. This may indicate that L. sibirica and P. sylvestris can be widely used for rehabilitation works in Mongolia attributed to their dominant distributions but also their high drought-resistance properties.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.59-66
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• 1984

Although it is well established that steroid is effective for treatment of neonatal respiratory distress syndrome (NRDS), the action mechanism of steroid on NRDS is not well known. Several authors have insisted that steroid increases secretion of pulmonary surfactant from type II pneumocyte, but others have insisted that steroid does not affect the secretory function of the type II pneumocyte. And some authors have suggested that steroid may ca use compositional change of pulmonary surfactant phospholipid. From these aspects, it is desirable to confirm the effect of steroid on (he secretory function of the type II pneumocyte. In order to know the effect of steroid on pulmonary surfactant activity, phospholipid phosphorus of lung lavage was measured and composition of pulmonary surfactant phospholipid of lung lavage was analyzed by thin layer chromatography (TLC) in control (C), pneumonectomized (PN), and pneumonectomized with betamethasone treated (PNS) rabbits. And lung weight and lung weight-body weight ratio were measured in each experimental group also. In PN group, right lung pneumonectomy was performed under general anesthesia with pentobarbital sodium (30mg/kg). On the fifth day after the surgery, the left lung was excised and measured above parameters. In PNS group, pneumonectomy was performed as PN group, and one day after the surgery, betamethasone was injected for four days intramusculary (4mg/day) and rabbits were sacrificed. The experiment yielded following results. PNS group's lung weight was significantly (p<0.01) heavier than C group's, but in comparison with PN group's it showed no significant change. PNS group's L/B ratio was significantly (p<0.05) higher than C group's, but compared with PN group's it showed no significant change. The value of phospholipid phosphorus content of PNS group was significantly (p<0.01) higher than that of C group. Even if the value of phospholipid phosphorus content in PNS group was not significantly higher than that of PN group, it showed increasing tendency compared with that of PN group. And in an analysis of the thin layer chromatogram, quantity (${\mu}mol/gm$ of wet weight lung) of phosphatidylcholine in PNS group decreased significantly (p<0.05) compared with C and PN group. From these results, it may be suggested that though steroid inhibits cellular hyperplasia in the compensatory growing lung, it auguments the secretory function of type II pneumocyte and causes compositional change of pulmonary surfactant phospholipid.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.4
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• pp.252-256
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• 2015

In this study, we propose a novel fabrication of an oxide-based lateral thermoelectric pn couple and investigate the characteristics of the thermoelectric couple. Electrospun ZnO and $LaSrCoO_3$ nanofibers are used as n- and p-legs of the couple, respectively. The Seebeck coefficients of the n- and p-type nanofibers and the pn couple are $-98.1{\mu}V/K$, $42.4{\mu}V/K$, and $118.8{\mu}V/K$, respectively. The thermoelectric couple generates an output voltage of $484.7{\mu}V$ at a temperature difference of 4.1 K.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.274-274
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• 2010

최근 들어 나노선을 이용한 pn 접합 소자 연구 결과가 매우 활발하게 보고되고 있다. 그러나, 서로 다른 두 종류의 나노선으로 pn 접합 어레이 구조의 소자를 제작할 때, 나노선을 원하는 위치에 정렬하는 기술상의 어려움이 큰 걸림돌이 된다. 본 연구에서는 p-CNT와 n-$SnO_2$ 나노선을 이용한 pn 접합 어레이 구조를 제작할 수 있는 독창적인 공정기술을 제안한다. 먼저 $SiO_2$가 300 nm 성장된 Si 기판을 선택적으로 패터닝하여 BOE (6:1) 용액으로 $SiO_2$ 층을 80 nm 정도 선택적으로 에칭한 후, 선택적으로 에칭된 표면에 슬라이딩 장비를 이용하여 화학기상증착법(chemical vapor deposition: CVD)으로 성장된 n-$SnO_2$ 나노선을 전이시킨다. 그 다음 thermal tape를 이용하여 CVD 법으로 성장된 랜덤 네트워크 형태의 CNT를 $SnO_2$ 나노선이 전이된 기판 위에 전이 시킨다. 이때 성장된 CNT 필름 중 금속성 나노선을 통한 전하 이동을 감소시키기 위해, 촉매로 사용되는 페리틴의 농도를 낮춰서 전체적인 CNT의 농도를 줄이는 방법을 이용하였다. 따라서, 성장된 CNT 필름은 별도의 후처리 없이 p-형의 반도체성을 보였다. 제작된 pn-소자는 정류비가 ~103 인 정류특성을 보였으며, 254 nm 파장의 UV lamp를 조사하여 광전류가 발생하는 것을 확인하였다. 연구결과는 이종의 나노선 접합에 의한 다이오드 응용과 UV 센서응용 가능성을 보여준다.