• 한국가축번식학회지
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• 제22권1호
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• pp.19-27
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• 1998

The present study was performed to investigate the patterns of a, pp.arance of lectin in uterus of fetuses of 90 and 120 days old and neonates of Korean native goat. The carbohydrate markers were used in histochemistry for the determination of the lectin by staining of avidin-biotin-per-oxidase complex(ABC), rincinus communis agglutinin(RCA-I), ulexeuropalus communis agglutinin(UEA) and wheat germ agglutinin(WGA). 1. The effects of this study were as follows; 1. The binding reactions for Con-A were weak on the mucosal epithelium of endometrium in 90 and 120 days old fetuses, and neonates and moderate at the free surface of mucosal epithelia. 2. The binding reactions for DBA was partially moderate on the mucosal epithelium of endometrium and partially strong at the free surface of mucosal epithelia in 120 days old fetuses. In neonates, the reactions were strong on the mucosal epithelium and gland primordium of endometrium, and the secretions at the free surface showed strong reactions for DBA. But, in 90 days old fetuses, the reaction was negative. 3. The binding reactions for RCA-I were moderate on the mucosal epithelium of endometrium and at the free surface of mucosal epithelia in 90 days old fetuses. In 120 days old fetuses, the reactions were weak on the mucosal epithelium of endometrium and moderate at the free surface of mucosal epithelia. In neonates, the reactions were moderate on the mucosal epithelium of endometrium and strong at the free surface of mucosal epithelia and also strong in the uterine gland. 4. The binding reactions for UEA were negative in 90 and 120 days old fetuses and neonates. 5. In 90 days old fetuses, the binding reactions for WGA were generally weak on the mucosal epithelium of endometrium, but several epithelial cells showed moderate reaction for WGA. In 120 days old fetuses and neonates, the reactions were moderate on the mucosal epithelium and blood vessels of endometrium and strong at the free surface of mucosal epithelia.

• 대한수의학회지
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• 제37권2호
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• pp.235-244
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• 1997

The present study was performed to investigate the patterns of appearance of lectin in trachea of fetuses of 60, 90 and 120 days old and neonates of Korean native goat. Carbohydrate markers were used in histochemistry for the determination of the lectin by staining of avidin-biotin-peroxidase complex(ABC), and the markers consisted of biotin-labeled concanavalin A(Con A), dolichos biflorus agglutinin(DBA), rincinus communis agglutinin(RCA-I), ulexeuropalus communis agglutinin(UEA) and wheat germ agglutinin(WGA). 1. The Con A-binding reactions appeared moderately on the apical surface of the tracheal epithelia in 60 days old fetuses, and the reactions were similar on the tracheal epithelia and glands in 90 and 120 days old fetuses and neonates. 2. Reaction of the DBA appeared as the strongest meanwhile the DBA-binding reactions were determined strongly on the apical surface of the tracheal epithelia in the 60 days old fetuses. Reaction for the DBA on the tracheal epithelia and glands of 90 and 120 days old fetuses and neonates were in same manner. 3. The RCA-I-binding reactions appeared very strongly on the apical surface of the tracheal epithelia in 60 and 90 days old fetuses. Reaction to the RCA-1 appeared moderately on certain apical surface of tracheal epithelia and glands in 120 days old fetuses and neonates. 4. No reactions provoked for the UEA in trachea of 60 days old fetuses and neonates, but the UEA-binding reactions appeared moderately in the tracheal epithelia of 90 days old fetuses and weakly in 120 days old fetuses. 5. The WGA-binding reactions appeared very strongly on the apical surface of the tracheal epithelia in 60 and 90 days old fetuses, and moreover, the reactions were determined on the luminal surface of the tracheal gland in 90 days old fetuses. On the other hand, goblet cells of the tracheal epithelia and glands in neonates reacted moderately to the WGA.

• 한국진공학회지
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• 제3권2호
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• pp.147-157
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• 1994

Valence or core electron excitations induced by Synchrotron radiation (SR) irradiation and ensuing chemical reactions can be applied for semiconductor processes i, e, deposition etching and modifications of thin film materials. Unique selectivity can be achieved by this photochemical reactions in deposition and etching. Some materials can be ecvaporated by SR irradiation which can be utilized for low temperature surface cleaning of thin films. Also SR irradiation significantly lowers the reaction temperature and photon activated surface reactions can be utilized for direct writing or projection lithography of electronic materials. This technique is especially effective in making nanoscale feature size with abrupt and well defined interfaces for next generation electronic devices.

• Applied Science and Convergence Technology
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• 제26권6호
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• pp.174-178
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• 2017

The reactions of thermal hydrogen atoms H(g) with the Ge(100) surface were examined with temperature-programmed desorption (TPD) mass spectrometry. Concomitant $H_2$ and $CH_4$ TPD spectra taken from the H(g)-irradiated Ge(100) surface were distinctly different for low and high H(g) doses/substrate temperatures. Reactions suggested by our data are: (1) adsorbed mono(${\beta}_1$)-/di-hydride(${\beta}_2$)-H(a) formation; (2) H(a)-by-H(g) abstraction; (3) $GeH_3$(a)-by-H(g) abstraction (Ge etching); and (4) hydrogenated amorphous germanium a-Ge:H formation. While all these reactions occur, albeit at higher temperatures, also on Si(100), H(g) absorption by Ge(100) was not detected. This is in contrast to Si(100) which absorbed H(g) readily once the surface roughened on the atomic scale. While this result is rather against expectation from its weaker and longer Ge-Ge bond as well as a larger lattice constant, we attribute the absence of direct H(g) absorption to insufficient atomic-scale surface roughening and to highly efficient subsurface hydrogenation at moderate (>300 K) and low (${\leq}300K$) temperatures, respectively.

• Journal of Electrochemical Science and Technology
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• 제7권2호
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• pp.179-184
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• 2016

The interface between the surface of a cathode material and the electrolyte gives rise to surface reactions such as solid electrolyte interface (SEI) and chemical side reactions. These reactions lead to increased surface resistance and charge transfer resistance. It is consequently necessary to improve the electrochemical characteristics by suppressing these reactions. In order to suppress unnecessary surface reactions, we coated cathode material using polypropylene (PP). The PP coating layer effectively reduced the SEI film that is generated after a 4.3 V initial charging process. By mitigating the formation of the SEI film, the PP-coated Li[(Ni_0.6Co_0.1Mn_0.3)_0.36(Ni_0.80Co_0.15Al0.05)_0.64)]O₂(NCS) electrode provided enhanced transport of Li⁺ ions due to reduced SEI resistance (R_SEI) and charge transfer resistance (R_ct). The initial charge and discharge efficiency of the PP-coated NCS electrode was 96.2 % at a current density of 17 mA/g in a voltage range of 3.0 ~ 4.3 V, whereas the efficiency of the NCS electrode was only 94.7 %. The presence of the protective PP layer on the cathode improved the thermal stability by reducing the generated heat, and this was confirmed via DSC analysis by an increased exothermic peak.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.65.1-65.1
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• 2013

Icy dust particles in interstellar clouds are considered to play a catalytic role in molecular evolution in space. Atoms and simple molecules constituting the ice mantles of dust particles may be transformed into more complex molecules under the irradiation of UV and cosmic rays. This seminar will present our recent study results for chemistry of ice surfaces, with the emphases on the mechanistic features of elementary reactions and the implications for interstellar molecular evolution. The types of reactions studied include molecule diffusion in ice, proton and hydroxide transfers, and some UV-induced reactions wih astrobiological relevance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1288-1290
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• 1998

Three most dominant reactions are adsorption, movement, and desorption of $SiCl_2$ on silicon surface. $SiCl_2$ plays a key role in these dominant reactions. In this paper, surface reactions of $SiH_2Cl_2-H_2-HCl$ system are investigated and few dominant reactions were identified. An equation for Si net growth rate is derived from the analysis of these reactions and it is compared with experimental results of Bolem and Classen.

• Journal of Electrochemical Science and Technology
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• 제11권4호
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• pp.411-420
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• 2020

Undesirable interfacial reactions between the cathode and sulfide electrolyte deteriorate the electrochemical performance of all-solid-state cells based on sulfides, presenting a major challenge. Surface modification of cathodes using stable materials has been used as a method for reducing interfacial reactions. In this work, a precursor-based surface modification method using Zr and Mo was applied to a LiNi_0.6Co_0.2Mn_0.2O₂ cathode to enhance the interfacial stability between the cathode and sulfide electrolyte. The source ions (Zr and Mo) coated on the precursor-surface diffused into the structure during the heating process, and influenced the structural parameters. This indicated that the coating ions acted as dopants. They also formed a homogenous coating layer, which are expected to be layers of Li-Zr-O or Li-Mo-O, on the surface of the cathode. The composite electrodes containing the surface-modified LiNi_0.6Co_0.2Mn_0.2O₂ powders exhibited enhanced electrochemical properties. The impedance value of the cells and the formation of undesirable reaction products on the electrodes were also decreased due to surface modification. These results indicate that the precursor-based surface modification using Zr and Mo is an effective method for suppressing side reactions at the cathode/sulfide electrolyte interface.

• Journal of Electrochemical Science and Technology
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• 제7권4호
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• pp.316-326
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• 2016

Development and discovery of efficient, cost-effective, and robust electrocatalysts are imperative for practical and widespread implementation of water electrolysis and fuel cell techniques in the anticipated hydrogen economy. The electrochemical reactions involved in water electrolysis, i.e., hydrogen and oxygen evolution reactions, are complex inner-sphere reactions with slow multi-electron transfer kinetics. To develop active electrocatalysts for water electrolysis, the physicochemical properties of the electrode surfaces in electrolyte solutions should be investigated and understood in detail. When electrocatalysis is conducted using nanoparticles with large surface areas and active surface states, analytical techniques with sub-nanometer resolution are required, along with material development. Scanning electrochemical microscopy (SECM) is an electrochemical technique for studying the surface reactions and properties of various types of electrodes using a very small tip electrode. Recently, the morphological and chemical characteristics of single nanoparticles and bio-enzymes for catalytic reactions were studied with nanometer resolution by combining SECM with atomic force microscopy (AFM). Herein, SECM techniques are briefly reviewed, including the AFM-SECM technique, to facilitate further development and discovery of highly active, cost-effective, and robust electrode materials for efficient electrolysis and photolysis.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1681-1688
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• 2010

Density functional theory was adopted to study the various surface products and their reaction channels focusing on the on-dimer configuration which has not been suggested before. Energetic results show that the most stable on-dimer configuration is the 6,6-[2+2] structure which resembles the typical [2+2] cycloaddition product. The 6,6-[2+2] product is also more stable than any other possible surface structures of inter-dimer configuration further suggesting its existence. Potential energy surface scan along various possible initial surface reactions show that some of the possible on-dimer surface products require virtually no reaction barrier indicating that initial population of on-dimer surface products is thermodynamically determined. Various surface isomerization reaction channels exist further facilitating thermal redistribution of the initial surface products.