• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.11 no.1
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• pp.32-55
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• 1975

The ammonium salt of N-Nitrosophenylhydroxiamine, namely Cupferron, is a well-known analytical reagent which precipitates a great number of metal ions in acid medium. Various structures of electrode reduction for N-Nitrosophenylhydroxiamine have been suggested in acid and alkaline media by many researchers, but not in neutral medium. So the mechanism of electrode reaction of Cupferron was investigated by both chronopotentiometric and polarographic methods. It was estimated that the reduction of Cupferron occurs in a three-step mechanism through which a chemical step is interposed between two charge transfer, the ECE (charge transfer-chemical reaction-charge transfer) mechanism, over a range of neutral and alkaline media. The chemical reaction of the process was assumed to be acid-base catalyzed from the fact that kapp (over all rate constant) of chemical reaction is pH dependent.

• Macromolecular Research
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• v.15 no.4
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• pp.302-307
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• 2007

The living radical polymerization of methyl methacrylate (MMA) by atom transfer radical polymerization, (ATRP) employing a $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine (PyP) catalytic system (X=Cl, Br), was investigated using several initiators and solvents at various temperatures. Most of the polymerizations with the PyP ligand were well controlled, with a linear increase in the number average molecular weights ($M_n$) vs. conversion, with relatively low molecular weight distributions ($M_w/M_n=1.2-1.4$) throughout the reactions. The measured weights matched those of the predicted values. The ethyl-2-bromoisobutyrate (EBriB) initiated ATRP of MMA, with the $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine catalytic system (X=Cl, Br), was better controlled in p-xylene at $80^{\circ}C$ than the other solvents used in this study.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.147-150
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• 2006

A new class of heat transfer fluid with higher thermal conductivity, called nanofluids has been developed by Dr. S. Choi about decade ago. Many exciting experimental and theoretical results have been reported worldwide to predict the thermal conductivity enhancement of nanofluids, however, they sometimes show excessive large discrepancies between each other. This kind of disagreements in thermal conductivity data is partly ascribable to the accuracy of the measuring apparatus, that is, mostly used THM(transient hot-wire method). New thermal conductivity measuring method whose principle is different from that of conventional THM is proposed in this article and measurements and uncertainty analysis were made for the three nanofluid samples with different particle concentration of pure, 2% and 4% of AlN nanofluids.

• BMB Reports
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• v.46 no.1
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• pp.53-58
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• 2013

We constructed deletion mutants and seven point mutants by polymerase chain reaction to investigate the specificity of feline foamy virus integrase functional domains. Complementation reactions were performed for three enzymatic activities such as 3'-end processing, strand transfer, and disintegration. The complementation reactions with deletion mutants showed several activities for 3'-end processing and strand transfer. The conserved central domain and the combination of the N-terminal or C-terminal domains increased disintegration activity significantly. In the complementation reactions between deletion and point mutants, the combination between D107V and deletion mutants revealed 3'-end processing activities, but the combination with others did not have any activity, including strand transfer activities. Disintegration activity increased evenly, except the combination with glutamic acid 200. These results suggest that an intact central domain mediates enzymatic activities but fails to show these activities in the absence of the N-terminal or C-terminal domains.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.169-169
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• 2001

Purpose： To assess the clinical usefulness of Transfer Insensitive Labeling Technique (TILT) in t evaluation of ischemic cerebrovascular disease. Method： Arterial spin labeling (ASL) is a method of perfusion weighted imaging usin endogenous water as a tracer. To avoid MT-related artifacts, which is common in usual A technique, a transfer insensitive labeling technique (TILT) was used, which globall manipulate macromolecular spins in the same way by both labeling and reference preparatio while free water is labeled in one case and left unchanged in the other. Philips Interal 1.5 T system was used. 40cm FOV and 32 repeated measurements were done because of the wea perfusion signal. 5 slices of supratentorial brain were obtained in 5 patients ｛MCA infar (n=3), moyamoya disease (n=2)｝. We simultaneously obtained contrast enhanced T2＊-weighted perfusion MRI and correlate to TILT images.

• Clean Technology
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• v.9 no.1
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• pp.43-48
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• 2003

As a result of study on factor affecting absorption efficiency using the structured packing, Mellapak N. 250Y for the chemical absorption of $CO_2$ that cause global warming due to development of industry, it is shown that Mellapak N. 250Y has lower pressure drop and superior efficiency of mass transfer than 25mm Pall ring. Also, in the absorption process, it produces high efficiency in the increase of load and concentration of absorption liquid and produces low efficiency in the increase of temperature. In the effect of overall mass transfer coefficient for 15% MEA on the temperature variation of absorbent, when absorbent temperature for 15% MEA varied as 25, 50, $80^{\circ}C$, overall mass transfer coefficients were shown as 0.83, 1.00, $0.90kmol/m^3-h-kPa$.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.284-284
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• 2010

We report a fabrication of 6, 13-bis(triisopropylsilylethynyl) (TIPS) pentacene nanowires that made on Si substrates by liquid bridge-nanotransfer molding (LB-nTM) with polyurethane acrylate (PUA) mold. LB-nTM is based on the direct transfer of various materials from a stamp to a substrate via a liquid bridge between them. In liquid bridge-transfer process, the liquid layer serves as an adhesion layer to provide good conformal contact and form covalent bonding between the TIPS-pentacene nanowire and the Si substrate. The patterned TIPS-Pentacene nanowires have been investigated by Atomic force microscopy (AFM), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and electrical properties.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.1049-1052
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• 2007

Extremely sharp and uniform Transfer Mold FEAs with thin film low work function TiN emitter material have been fabricated by controlling the thickness of the coated emitter materials to realize high efficient, high reliable and low-cost vacuum nanoelectronic devices..Their tip radii are 8.3-13.8 nm. Turn-on electric fields of the Ni FEAs and TiN-FEAs resulted in the low electric field values of $31.6\;V/{\mu}m$ and $44.2V/{\mu}m$,respectively, at the short emitter/anode distance: less than $30\;{\mu}m$, which are lower than those of conventional FE As such as Spindt type FEAs and carbon nan otube FEAs The Transfer Metal Mold fabrication method is one of the best methods of changing emit ter materials with sharp and uniform emit ter shapes.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3693-3696
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• 2010

We experimentally measure the kinetic energy and angular distributions of photoelectrons of $N_2$ as a function of 410 nm femtosecond laser intensity by using velocity map imaging technique. The strong-field multiphoton ionization of molecules shares many of the characteristics with those of atoms. Electron kinetic energies are nearly independent of laser intensities. The independence suggests that the electron peaks in the photoelectron spectrum actually result from a two-step process, indicative of the occurrence of real population in the intermediate states. The relative amplitudes of electron peaks indicate that in the two-step process, nonresonant population transfer dominates for low intensities, while resonant population transfer dominates for higher intensities.

• Journal of the Korean Applied Science and Technology
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• v.18 no.1
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• pp.49-54
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• 2001

Ultra-thin films of organic charge transfer complex were prepared on a hydrophilic substrate by Langmuir-Blodgett(LB) technique. In this study, the photoelectric properties of a LB film consisting of (N-docosyl quinolinium)-TCNQ(1:2) complex was investigated. The visible light(${\lambda}$ : 700 nm) of xenon lamp was illuminated on the LB films and light absorptivity and photoconductivity were observed. The photocurrent increased linearly and was saturated at the light intensity of 23 ${\mu}W/cm^{2}$.