• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1671-1674
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• 2003

The effects of amine donors ($a:NH_2,\;b:NMe_2,\;c:NMePh,\;d:NPh_2$) and conjugation length on the molecular hyperpolarizabilities of a series of dipolar molecules have been theoretically investigated by using CPHF/6-31G method. The first hyperpolarizabilities (${\beta}$) of p-nitrobenzene derivatives increase with the donor in the order, $NH_2\;<\;NMe_2\;<\;NMePh\;<\;NPh_2$, whereas slightly different order is observed in more conjugated derivatives, i.e., $NH_2\;<\;NPh_2\;<\;NMe_2\;<\;NMePh$. The result has been attributed to the extent of charge transfer and torsion angle. Moreover, the results show that "non-traditional" ${\pi}$-conjugation effect exists in small compounds and decreases as the conjugation length between donor and acceptor increases.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.106-107
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• 2011

Organic Light Emitting Diode(OLED), Optical Photovotaic Device(OPV)와 같은 유기소자에서 전극으로 적용되어지고 있는 Indium Tin Oxide (ITO) 박막의 유연성을 향상시키기 위하여 중간층으로 투명도(~80%)와 전도도(~1000 S/cm)가 우수한 PEDOT:PSS(PH1000)을 적용하였다. PEDOT:PSS(PH1000)의 적용으로 인하여 ITO 박막의 유연성이 현저히 개선됨과 동시에 PEDOT:PSS(PH1000)의 우수한 전도도로 인하여 보다 얇은 ITO의 두께에서도 우수한 면 저항(25 ${\Omega}/{\square}$ ~ 220 ${\Omega}/{\square}$) 및 비저항(3.75E-4 ${\Omega}{\cdot}cm$ ~ 4.40E-4 ${\Omega}{\cdot}cm$)의 값을 측정하였다.

• Textile Coloration and Finishing
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• v.17 no.6 s.85
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• pp.36-41
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• 2005

The effects of low temperature plasma treatment on the properties of three types of foams, polyurethane(PU), injection phylon(IP), and phylon(PH) that used for footwear mid-sole were examined. The change of surface properties of foams were characterized by electron scanning microscope, contact angle measurement, and universal testing machine. Adhesion was tested by T-peel tests of plasma treated foams/polyurethane adhesive joints. The contact angle of three types of foams were decreased dramatically with the plasma treatment time, specifically noticeable in the case of phylon(Ph). It has shown the relationship with the contact angle of phylon(PH) and the distance between electrode and samples. The peel strength of foams were increased with the increase of plasma treatment time.

• Journal of Korea Foundry Society
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• v.13 no.2
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• pp.163-167
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• 1993

Mechanical and chemical properties of the 17-4PH have been investigated after recycled melting. As the result, it has been ascertained that the change of Ni, Cu, Nb, C amount affects the mechanical and chemical properties. It is important to minimize contamination of impurities and to control the amount of Ni, Cu, Nb, C.

• Korean Journal of Microbiology
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• v.10 no.2
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• pp.87-92
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• 1972

In order to study on the pigment and protease of Serratia marcescens, the correlation between protease activity and pigment formation was investigated. The results are as follows ; 1) The protease activity exhibitied two pH optima 6.0 and 7.5, respectively. 2) The optimal temeprature of proteolytic activity was 45.deg.C. With these-results, it is suggested that the proteolytic enzymes of Serratia masrecescens is stable at neutral pH range and more active at the high temeprature than lthat of otehr proteolytic enzymes.

• Journal of the Korean Society for Heat Treatment
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• v.6 no.3
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• pp.152-158
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• 1993

Effects of oxide film which is grown by heat treatment on the hydrogen embrittlement (HE) of 17-4 PH stainless steel were investigated. Specimems were tensile tested after cathodic hydrogen charging and the be haviors of HE were evaluated from the elongation change. It was found that specimems solution treated at $1040^{\circ}C$ for 1/2hour showed best retardation ability to HE for both aging conditions i.e. $480^{\circ}C{\times}1hr$ and $620^{\circ}C{\times}4hrs$. X-ray and Auger study revealed that the major composition of oxide films are $Cr_2O_3$ and $CuCr_2O_4$.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.3
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• pp.309-316
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• 2021

In this paper, the electrical power output of the micro-combustor thermophotovoltiac(TPV) system was analyzed. The system consists of a micro-combustor, photonic crystals(PhCs), and photovoltaic cells(PV cells). The system has a micro-combustor that can achieve over 1,000 K surface temperature by consuming 2.5 g/h hydrogen fuel. Also, this system incorporates current state-of-the-art PhCs surfaces(2D Ta PhCs and Tandem Filter) to increase electrical power output. In addition, InGaAsSb PV cell, which bandgap is 0.55 eV, was applied to convert a wide range of radiative energy. The performance analysis shows that a single micro-combustor TPV system can produce 0.4 W ~ 27.7 W electrical power with the temperature change of emitter(900 K ~ 1,500 K) and PV cell(250 K ~ 400 K).

• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.305-310
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• 1997

The synthesis and characterization of the platinum heterocyclic carboxaldehyde thiosemicarbazone complexes [NC5H4CRNNC(S)NHR'PtCl] (R=H, R'=CH3(1); R=CH3, R'=CH3(2); R=CH3, R=H(3)) and diphenylphosphinophenyl carboxaldehyde thiosemicarbazone complexes [Ph2PC6H4CHNNC(S)NHRPtCl] (R=CH3(5); R=iC3H7(6); R=Ph(7)) are described. Compounds 1-3 were prepared by reaction of Pt(SEt2)2Cl2 with 2-acetylpyridine-4-alkylthiosemicarbazone in the presence of NEt3. Compounds 5-7 were prepared using Pt(SEt2)2Cl2 in toluene with diphenylphosphinophenyl carboxaldehyde alkylthiosemicarbazone. The compounds have been characterized by microanalysis, NMR (1H, 13C, 31P) spectroscopy, and single-crystal X-ray diffraction. X-ray single crystal diffraction analysis reveals that compound 5 is a mononuclear platinum compound with P,N,S-coordination mode.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.6
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• pp.754-757
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• 1986

Boron monophosphide(100) was eitaxially grown on Si(100) substrate by thermal reaction of B2H6 and PH3 in hydrogen ambient. In an LPCVD system, the growth condition was studied as a function of gas mixture composition and temperature. For the growth temperature of 950\ulcorner in the constant flow rate (partial pressure) of B2H6, n-BP with c(2x2) surface structure was obtained in the PH3 partial pressure of 300-500 cc/min. On the other hand, for the growth temperature of 1080\ulcorner, p-BP with surface structure was observed for the PH3 partial pressure of 400-500cc/min.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.150-160
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• 1999

Background: The CREST syndrome is an indolent form of progressive systemic sclerosis. Although its clinical progress is indolent, pulmonary hypertension(PH) associated with CREST syndrome have grave prognosis with over 40 percent mortality rate at 2 year follow-up. But the pathogenesis of pulmonary hypertension in this disease is not known, and classified as either primary or secondary PH. Clonality of endothelial cell proliferation in plexiform lesion is a molecular marker which allows distinction between primary and secondary PH. We performed this study to know whether the PH associated with CREST syndrome is a variant of primary PH or is a secondary PH. Methods: We assessed the X-chromosome inactivation based on the methylation pattern of the human androgen-receptor gene by PCR(HUMARA). Endothelial cells in plexiform lesions from female patients(n=3) with PH associated with CREST syndrome were microdissected from paraffin blocks. Vascular smooth muscle cells and lung parenchyma were also microdissected for clonality studies. Results: The proliferating endothelial cells in 14 plexiform lesions were all polyclonal. Similarly proliferated smooth muscle cells from 5 vessels with medial hypertrophy were also polyclonal. Conclusion: These results suggest that the pulmonary hypertension associated with CREST syndrome has different pathogenesis from primary PH and to be classified as secondary PH.