• Analytical Science and Technology
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• v.11 no.5
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• pp.332-340
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• 1998

Tridentate Schiff base ligands, $SIPH_2$, $SIPCH_2$, $HNIPH_2$, and $HNIPCH_2$ were prepared by the reactions of salicylaldehyde and 2-hydroxy-1-naphthaldehyde with 2-aminophenol and 2-amino-p-cresol. Ni(II) complexes of those ligands were synthesized. The structures and properties of ligands and their complexes were studied by elemental analysis, $^1H$-NMR, IR, UV-visible spectra, and thermogravimetric analysis. The mole ratio of Schiff base to the metal of complexes was found to be 1:1. Ni(II) complexes were contemplated to be hexa-coordinated octahedral configuration containing three water molecules. The redox process of ligands and complexes in DMSO solution containing 0.1 M TBAP as supporting electrolyte was investigated by cyclic voltammetry and differential pulse voltammetry with glassy carbon electrode. The redox process of the tridentate Schiff base ligands was totally irreversible. The redox process of Ni(II) complexes were quasi-reversible and diffusion-controlled as one electron by one step process Ni(II)/Ni(I). The reduction potentials of the Ni(II) complexes shifted in the positive direction in the order [$Ni(II)(HNIP)(H_2O)_3$]>[$Ni(II)(SIP)(H_2O)_3$]>[$Ni(II)(SIPC)(H_2O)_3$]>[$Ni(II)(HNIPC)(H_2O)_3$] and their dependence on ligands were not so high. Consequently the [$Ni(II)(HNIPC)(H_2O)_3$] complex among the synthesized Ni(II) complexes was found to be most stable in the DMSO solution.

• The Korean Journal of Pesticide Science
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• v.6 no.2
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• pp.72-79
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• 2002

3D-QSAR between fungicidal activitives ($pI_{50}$) against metalaxyl-sensitive (SPC: 95CC7105) or metalaxyl-resisitant (RPC: 95CC7303) isolate of phytophthora blight fungus (Phytophthora capsici), and a set of 3-phenylisoxazole (A) and 3-phenyl-2,5-dihydroisoxazole (B) derivatives as substrates were conducted using comparative molecular field analyses (CoMFA). The antifungal activities of (A) were generally higher than those of (B). And it is assumed that the most stable conformation of the active substrate was approximately planar from conformational search. The CoMFA models proved a good predictive ability and suggested that the electronic field of substrates were higher than hydropohobic field and steric field requirements for recognition forces of the receptor site. And the factors were strongly correlated (cross-validated $q^2>0.570$ & conventional $r^2>0.968$) with the fungicidal activitives. According to the CoMFA analyses, the selectivity factors for RPC suggested that the sterically bulky groups (C14 & C15) and electron withdrawing groups (C15 & C16) have to be introduced to the ortho, meta and para-position on the benzoyl moiety of substrates.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.5
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• pp.509-515
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• 2012

In this study, ${\gamma}-Al_2O_3$ nanoparticles were synthesized by using coflow hydrogen diffusion flames. The synthesis conditions were varied with using several oxygen concentrations in the oxidizing air. The particle characteristics of the flame-synthesized $Al_2O_3$ nanoparticles were determined by examining the crystalline structure, shape, and specific surface area of the nanoparticles. The measured maximum centerline temperature of the flames ranged from 1507.8 K to 1998.7 K. The morphology and crystal structure of the $Al_2O_3$ nanoparticles were determined from SEM images and XRD analyses, respectively. The particle sizes were calculated from measured BET specific surface areas and ranged from 25 nm to 52 nm. From XRD analyses, it was inferred that a large number of the synthesized nanoparticles were ${\gamma}-Al_2O_3$ nanoparticles including ${\theta}-Al_2O_3$ nanoparticles.

• Korean journal of applied entomology
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• v.17 no.3 s.36
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• pp.131-138
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• 1978

A virus named Cymbidium mild mosaic virus(Cy MMV), was mechanically transmitted to Chenopodium amaranticolor from the leaves of Cymbidium with mild mosaic symptoms. The virus was cultured in C. amaranticolor, in which it produced local chlorotic and ring spots, followed by systemic vein clearing with distortion. CyMMV infected 7 out of 35 species of plants. In C. amaranticolor juice infectivity was lost by heating at $90^{\circ}C$ for 10 miuntes, and by aging at$20^{\circ}C$ for 60 days, and by diluting at $10^{-6}$ when bioassayed on C. amaranticolor. CyMMV was not transmitted by Myzus persicae. The virus was purified after clarification of homogenized C. amaranticolor leaf tissues with chloroform, by differential centrifugation followed by sucrose density gradient centrifugation. Electron microscopic examination of purified preparation showed spherical particles of 28nm in diameter. The UV absorption spectrum of purified preparation was typical of u nucleoprotein (max. at 261nm. min. at 243nm), and showed 260/280=1.72 and max/min=1.26. The value of the sedimentation coefficient of the virus was S20.w=126. In gel-diffusion tests, CyMMV antiserum reacted with CarMV, but not with any of four other viruses (BBWV, CRSV, CMV, TBRV) having similar particles and properties in vitro. In ultra-thin sections of CyMMV infected tissues, a large number of virus particles were found in the cytoplasm of mesophyll cells and in xylem vessels.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.162-162
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• 2010

InSb has received great attentions as a promising candidate for the active layer of infrared photodetectors due to the well matched band gap for the detection of $3{\sim}5\;{\mu}m$ infrared (IR) wavelength and high electron mobility (106 cm2/Vs at 77 K). In the fabrication of InSb photodetectors, passivation step to suppress dark currents is the key process and intensive studies were conducted to deposit the high quality passivation layers on InSb. Silicon dioxide (SiO2), silicon nitride (Si3N4) and anodic oxide have been investigated as passivation layers and SiO2 is generally used in recent InSb detector fabrication technology due to its better interface properties than other candidates. However, even in SiO2, indium oxide and antimony oxide formation at SiO2/InSb interface has been a critical problem and these oxides prevent the further improvement of interface properties. Also, the mechanisms for the formation of interface phases are still not fully understood. In this study, we report the quantitative analysis of indium and antimony oxide formation at SiO2/InSb interface during plasma enhanced chemical vapor deposition at various growth temperatures and subsequent heat treatments. 30 nm-thick SiO2 layers were deposited on InSb at 120, 160, 200, 240 and $300^{\circ}C$, and analyzed by X-ray photoelectron spectroscopy (XPS). With increasing deposition temperature, contents of indium and antimony oxides were also increased due to the enhanced diffusion. In addition, the sample deposited at $120^{\circ}C$ was annealed at $300^{\circ}C$ for 10 and 30 min and the contents of interfacial oxides were analyzed. Compared to as-grown samples, annealed sample showed lower contents of antimony oxide. This result implies that reduction process of antimony oxide to elemental antimony occurred at the interface more actively than as-grown samples.

• Polymer(Korea)
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• v.25 no.1
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• pp.6-14
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• 2001

The monomer N,N'-bis(3-pyrrol-1-yl-propyl)-4,4'-bipyridinium$(PF_6)_2$ was electrochemically polymerized on glassy carbon electrode surface. This polymer film electrode has electroactive sites on its bipyridinium ions distributed at the polymer strands. The formal potentials of the electrodes were -0.41V and -0.81V(vs. SSCE) for each step at phosphate buffer(pH=5.70). The diffusion coefficients of the dopants ions into the polymer matrix were $1.57{\times}10^{-4}$ and $4.35{\times}10^{-5}cm^2s^{-1}$ for first and second redox couple, respectively. The rate constants of electron transfer at $V^{2+/+}$ of the first step was a $57.53s^{-1}$, which was 22 times higher than $V^{+/0}$ one having $2.63s^{-1}$ in the solution. The charge transfer resistance of the polymer film was influenced by the dopant ion of the electrolyte. Thus the resistances were 22.63, 16.81, 12.44 and $11.36k{\Omega}$ for $LiClO_4,\;NaClO_4,\;KClO_4$, and phosphate buffer, respectively. The reaction order of the electropolymerization was first order and the rate constant of the polymerization was $1.31{\times}10^{-1}s^{-1}$ as determined by EQCM method. The G.C./p-BPB type electrode doped with phosphate ions showed a stability and reproducibility in CV procedure over 20 cycles.

• Applied Microscopy
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• v.31 no.2
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• pp.185-197
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• 2001

Human gastric adenocarcinomas are fixated with low energy of microwave (LEM) to study fixation effects in level of ultrastructure and antigenicity of the cancer. For the Ag-Ab reactions , the LEM fixated sdenocarcinomas are incorporated with monoclonal mouse anti-human p53 (IgG2b, kappa) and rabbit anti human cerbB-2. The retrieval of antigenicity are easily recognizable in the LEM fixated sections compared with that of frozen sections which show often diffused colour reactions. And the LEM fixation methods have preserved ultrastructures of the adenocarcinoma, but it was often difficult to maintain constancy in fixation effects. For the constancy, LEM was coupled with low concentration of chemical fixatives, such as glutaraldehyde (<1%) and $OsO_4$ (<0.5%). The results were acceptable, but there are tendencies that the adenocarcinoma requisitioned rather weak microwave energy to come into the optimal fixation effects. Therefore , cultured HeLa cells were fixated with lower energy of microwave than that used to the adenocarcinoma. The ultrastructures of the single HeLa cell have been preserved. The results may imply that a different energy levels of microwave are requisitioned in accordance with kinds of cells and tissues for the optimal fixation effects. It is reported and discussed that the fixation methods of LEM used in this work could be applied routinely to conceal a insufficient diffusion rate of chemical fixatives into some kinds of cancer without compromising the ultrastructures as well as to improve antigenic quality of frozen sections.

• Journal of the Korean Vacuum Society
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• v.7 no.1
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• pp.17-23
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• 1998

$Pb(Fe_{0.5}Nb_{0.5}O_3(PFN)$ thin films were prepared by rf magnetron co-sputtering method on $SiO_2/Si$, ITO/glass, and $Pt/Ti/SiO_2/Si$ substrates and post-annealed at the $N_2$ atmosphere by RTA(rapid thermal annerling). The degree of crystallinity of PFN films was identified on various substrates. Electrical properties of PFN films was characterized for $Pt/PFN/Pt/Ti/SiO_2/Si$ structure. The composition of PFN films was estimated by EPMA (electron probe micro analysis). PFN films would be crystallized better to perovskite phase on ITO/glass substrate than $SiO_2/Si$ substrate. This may be induced by the deformation of Pb deficient pyrochlore phase due to Pb diffusion into $SiO_2/Si$ substrate. PFN films on $Pt/Ti/SiO_2/Si$ substrate. PFN films with 5-10% Pb excess were crystallized to perovskite phase from $500^{\circ}C$ temperature. In summary, we show that Pb composition and annealing temperature were critically influenced on crystallinity to perovskite phase. When PFN film with 17% Pb excess was annealed at $600^{\circ}C$ at the $N_2$ atmosphere for 300kV/cm and 88. Its remnant polarization coercive field $2.0 MC/cm^2$ and 144kV/cm, respectively.

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.15-21
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• 1984

The virus infecting French bean (Phaseolus vulgaris L.) was identified as Bean Common Mosaic Virus(BCMV) based on the host range, symptomatology, serology, morphology of virus particles and inclusion bodies. Isolates of BCMV were obtained from seeds of P. vulgaris collected at Suweon, Jangsu and Jinju in Korea. French bean produced vein clearing, mosaic, stunting and leaf curling. Symptom of Chenopodium quinoa was local lesions on the inoculated leaves, not on the upper leaves. The electron micrograph of the virus from French bean was flexuous approximately 750nm in length. Cylindrical and pinwheel cytoplasmic inclusion bodies were observed in French bean leaf infected by BCMV. BCMV from the French bean was transmitted through seed and green peach aphid, Myzus persicae. The thermal inactivation point was $55\~60^{\circ}C$, dilution end point was $10^{-3}\~10^{-5}$ and longevity in vitro was $2\~3$ days for BCMV from French bean. The isolates of BCMV reacted positively against BCMV antiserum. The extract of BCMV infected bean leaves, Azukibean mosaic virus (AZMV) and Cowpea aphid borne mosaic virus(CaMV) also reacted with BCMV antiserum, however, BCMV and CaMV showed the spur in agar gel diffusion test.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.4
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• pp.27-36
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• 2006

We fabricated thermally evaporated 10 nm-Ni/(poly)Si, 10 nm-Ni/l nm-Ir/(poly)Si and 10 nm-Ni/l nm-Pt/(poly)Si films to investigate the thermal stability of nickel monosilicides at the elevated temperatures by rapid annealing them at the temperatures of $300{\sim}1200^{\circ}C$ for 40 seconds. Silicides of 50 nm-thick were formed on top of both the single crystal silicon actives and the polycrystalline silicon gates. A four-point tester was used to examine sheet resistance. A scanning electron microscope and field ion beam were employed for thickness and microstructure evolution characterization. An X-ray diffractometer and an Auger depth profiler were used for phase and composition analysis, respectively. Nickel silicides with platinum have no effect on widening the NiSi stabilization temperature region. Nickel silicides with iridium farmed on single crystal silicon showed a low resistance up to $1200^{\circ}C$ while the ones formed on polycrystalline silicon substrate showed low resistance up to $850^{\circ}C$. The grain boundary diffusion and agglomeration of silicides lowered the NiSi stable temperature with polycrystalline silicon substrates. Our result implies that our newly proposed Ir added NiSi process may widen the thermal process window for nano CMOS process.