• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.979-984
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• 2011

Although sludge production has been increased due to the number of the wastewater treatment plants expanded, needs of the techniques for the sludge reduction and disposal has been issued importantly because the sludge dumping to ocean is prohibited from 2012 by the London Dumping Convention. Therefore, the sludge solubilization using electrolysis as an alternative techniques for the sludge disposal was carried out in this study. Iridium coated titanium based insoluble electrodes were used and 20 volt was applied to the electrolysis reactor using DC power supply. Supernatants of the treated sludge was monitored: The soluble COD, TN, TP of it was increased to 151%, 22% and 6% respectively. And the sludge floc size distribution was changed, that is, the flocs ranged from 0.1 to 1.0 ${\mu}m$ were increased. All of these results indicate that the cells were lysed and the internal matters bursted out of the cell after electrolysis. As well as the reduction of the sludge production, the soluble organic matters from the cells could be used as an external carbon sources in the advanced wastewater treatment plants.

• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.961-966
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• 1994

Oligomerization of phenylacetylene is catalyzed by $Rh(ClO_4)(CO)(PPh_3)_2$ (Rh-1), $[Rh(CO)(PPh_3)_3]ClO_4$ (Rh-2), $[Rh(COD)L_2]ClO_4 (L_2=(PPh_3)_2$, Rh-3; $(PPh_3)(PhCN)$, Rh-4; $(PhCN)_2$, Rh-5), $[Rh(C_3H_5)(Cl)(CO)(SbPh_3)_2]ClO_4$ (Rh-6), $[Ir(COD)L_2]ClO_4 (L_2=(PPh_3)_2$, $Ir-1; (PPh_3)(PhCN)$, $Ir-2; (PhCN)_2$, Ir-3; (AsPh_3)(PhCN)$, $Ir-4; Ph_2PCH_2CH_2PPh_2$, Ir-5; COD, Ir-6 and 2,2'-dipyridyl, Ir-7), $Ir(ClO_4)(CO)(PPh_3)_2$, $Ir-8, [Ir(PhCN)(CO)(PPh_3)_2]ClO_4$, Ir-9 to produce dimerization products, 1,3-diphenylbut-1-yn-3-ene, 1, (E)-1,4-diphenylbut-1-yn-3-ene, 2 and (Z)-1,4-diphenylbut-1-yn-3-ene, 3, and cyclotrimerization products, 1,3,5-triphenylbenzene, 4 and 1,2,4-triphenylbenzene, 5. Product distribution of the oligomers varies depending on various factors such as the nature of catalysts, reaction temperature, counter anions and excess ligand present in the reaction mixtures. Increasing reaction temperature in general increases the yield of the cyclotrimerization products. Exclusive production of dimer 1 and trimer 4 can be obtained with Ir-1 at 0 $^{\circ}$C and with Ir-2 in the presence of excess PhCN (or $CH_3CN$) at 50 $^{\circ}$C, respectively. Dimer 2 (up to 81%) and trimer 5 (up to 98%) are selectively produced with Rh-1 at 50 and 100 $^{\circ}$C respectively. Production of 3 is selectively increased up to 85% by using $PF_6$- salt of $[Ir(COD)(PPh_3)_2]$+ at 25 $^{\circ}$C. Addition of $CH_3I$ to Rh-1 produces $CH_3PPh_3^+I-$ and increases the rate of oligomerization(disappearance of phenylacetylene). Among the metal compounds investigated in this study, Ir-1 catalyzes most rapidly the oligomerization where the catalytically active species seems to contain lr(PPh3)2 moiety. The stoichiometric reaction of phenylacetylene wth Ir-9 at 25 $^{\circ}$C quantitatively produces hydridophenyl-ethynyl iridium(III) complex, $[lr(H)(C{\equiv}CPh)(PhCN)(CO)(PPh_3)_2]ClO_4$ (Ir-11), which seems to be an intermediate for the oligomerization.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.111.1-111.1
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• 2015

As an alternative way to get sophisticated nanostructures, atomic force microscopy (AFM) has been used to directly manipulate building primitives. In particular, assembly of metallic nanoparticles(NPs) can provide various structures for making various metamolecules. As far, conventionally made polygonal shaped metallic NPs showed non-uniform distribution in size and shape which limit its study of fundamental properties and practical applications. In here, we optimized conditions for deterministic manipulation of ultra-smooth and super-spherical gold nanoparticles (AuNPs) by AFM. [1] Lowered adhesion force by using platinum-iridium coated AFM tips enabled us to push super-spherical AuNPs in linear motion to pre-programmed position. As a result, uniform and reliable electric/magnetic behaviors of assembled metamolecules were achieved which showed a good agreement with simulation data. Furthermore, visualization of near field for super-spherical AuNPs was also addressed using photosensitive azo-dye polymers. Since the photosensitive azo-dye polymers can directly record the intensity of electric field, optical near field can be mapped without complicated instrumental setup. [2] By controlling embedding depth of AuNPs, we studied electric field of AuNPs in different configuration.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.9
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• pp.808-811
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• 2007

Aspheric glass lens have recently been used in camera phone module because they are more effective than spherical ones. In this paper, the grinding condition of the tungsten carbide molding core has been found after applying DOE to the development of the aspheric glass lens for the 3 Megapixel and 2.5x camera-phone module. Also, the ultra precision grinding process was investigated under this condition by experiment. Re-Ir coating was applied on the ground surface of the tungsten carbide molding core. The influence of Re-Ir coating on the form accuracy and surface roughness of molding core was compared and evaluated. The form accuracy and surface roughness of the molding core were improved by application of Re-Ir coating on the surface of the tungsten carbide molding core.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.508-508
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• 2013

백색 유기발광소자는 전색 디스플레이, 액정디스플레이의 backlights, 조명에서 잠재적인 가능성 때문에 디스플레이와 조명 업계에서 각광 받고 있다. 백색 유기발광소자를 제작하기 위한 방법으로 형광체를 이용한 백색 유기발광소자가 연구되고 있지만, 아직 색순도와 색좌표에 대한 연구가 필요하다. 본 연구에서는 무기물 형광체를 이용한 백색 유기발광소자의 전기적 특성과 광학적 특성을 관찰하였다. 광원으로 사용된 청색 유기발광소자에 적색과 녹색의 무기물 형광체를 결합하는 방법으로 백색 유기발광소자를 제작하였다. 광원으로 사용한 청색 유기발광소자의 양극으로는 투명전극으로 널리 쓰이고 있는 ITO를 사용하였고 정공 수송층으로는 N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine, 청색 발광층으로는 1,3-bis(carbazol-9-yl) benzene 호스트에 bis (3,5-difluoro-2-(2-pyridyl)phenyl)-(2-carboxypyridyl) iridium (III) 청색인광도 펀트를 사용하였다. 정공 저지층과 전자 수송층으로는 각각 2,9-dimethyl-4,7-diphenyl-1,10-phenanthorlene와 4,7-diphenyl-1,10-phenanthroline을 사용하고 전자 주입층으로는 lithium quinolate를 사용하였으며 음극으로는 Al을 사용하였다. 색 변환층으로 사용된 유기물 형광체는 sol-gel 방법으로 제작된 적색 형광체와 녹색 형광체를 사용하였다. Sol-gel 방법으로 제작된 형광체에 대한 주사현미경 측정 결과 입자의 표면이 고르고 크기가 작고 균일하였고, 높은 온도 열처리에 따라서 용매제가 대부분 제거되어 형광체 발광 특성이 잘 일어났음을 확인하였다. 제작한 백색유기발광소자에서 혼합비율에 따른 전계발광 특성 변화를 관찰하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.499-499
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• 2013

유기 발광 소자는 낮은 구동전압, 낮은 소비전력, 높은 명암비, 넓은 시야각 및 빠른 응답속도의 장점을 가지고 있기 때문에 전색 디스플레이에서 각광을 받고 있다. 고효율의 청색 유기 발광 소자를 제작하기 위해서 다양한 구조를 제작하고 있지만, 적색 및 녹색 유기 발광 소자에 비해 낮은 효율, 색 순도의 저하 및 짧은 수명으로 인한 문제점을 갖고 있기 때문에 이를 해결하기 위한 연구가 필요하다. 본 연구에서는 발광층내에 호스트 물질로 1.3-Bis(carbazol-9-yl) benzene (mCP)와 2-t-butyl-9,10-di-2-naphthylanthracene (TBADN)을 혼합하였고, 형광 도펀트인 4,40-Bis[4-(diphenylamino)styryl]biphenyl (BDAVBi) 또는 인광 도펀트인 bis(3,5-difluoro-2-(2-pyridyl) phenyl-(2-carboxypyridyl)iridium III (FIrpic)을 혼합한 발광층을 사용한 유기 발광 소자를 제작하여 전기적인 특성과 발광 효율을 관찰하였다. 유기 발광 소자의 정공 수송층 N,N,'-bis-(1-naphthyl)-N,N'-diphenyl1-1'-biphenyl-4,4'-diamine (NPB)와 정공 저지층 3-Benzidino-6-(4-chlorophenyl) pyridazine (BCP) 사이에 호스트 mCP와 도펀트 TBADN：BDAVBi를 혼합한 발광층의 혼합비율을 최적화 할 때 구동전압이 낮고, 발광효율이 증가됨을 확인하였다. 호스트 mCP에 도펀트를 혼합한 발광층에서는 호스트로 mCP 또는 TBADN만 사용하였을 때보다 전계발광 스펙트럼의 최대치가 청색 영역에서 나타남을 확인하였다. Commission Internationale de l'Eclairage (CIE) 측정을 통해, 호스트 mCP와 도펀트 TBADN : BDAVBi의 최적화된 혼합비에서 전압의 변동에 따른 CIE 값이 매우 안정적임을 확인하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.218-222
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• 2011

During the development of the iridium catalyst for domestic production, the catalyst failure, loss, sintering phenomena are observed by high pressure and temperature. By these abnormal failure of catalyst bed, the performance of thruster is degraded. To figure out the detail phenomena on the damaged catalyst bed, a numerical analysis code is developed by assuming the catalyst bed as an one dimensional porous media. The numerical analysis code is validated with experiment data. Thereby, resulting physical phenomena are examined by considering the variation of catalyst bed characteristics incurred by catalyst granule failure. Through these numerical analyses we figure out the effect of the catalyst loss on the decomposition of hydrazine and ammonia.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.227-232
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• 2004

Ballast water from ship harmful microorganism sterilized use of electrolytic sterilization system. The experimental methods were use of peristaltic flow pump upward on electrode pole. Due to reaction time, HRT were unlike microorganism on flow rate. In electrolysis, dioxide iridium coated titanium(Ti／IrO$_2$) and stainless steel plate were used for anode and cathode respectively. Current density controls make use of D.C Power supply on 250V 100Amper. Experimental use of current density between 0.1 and 0.5A was able to disinfect microorganism at 5 seconds by the reaction time. This study shows that the electrolyzed water has a potential for the sterilization of ballast water.

• Journal of Technologic Dentistry
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• v.31 no.3
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• pp.15-20
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• 2009

The success of the porcelain fused to gold alloy restoration depends not only on the choice of materials but to a larger degree on the technical skills. The porcelain fused to metal(PFM) alloys containing gold are commonly use for dental purposes in dental laboratory. The gold-colored alloys contain primarily gold, platinum, palladium, and silver, with minimum amounts of such metals as tin, iridium, or titanium. The purpose of this study is on the metal-porcelain fusing layer in porcelain fused to high gold alloy Principal results are as follows. The hardness number(Hv) of PFG is respectively $140.2{\pm}12.6$ in as-casted, $164.3{\pm}14.3$ in heat-treated, $186.6{\pm}20.4$ in fired-treated. The formation of the fusing(intermediate) layer caused by components fusing the interface of porcelain and gold alloy. The main components of the fusing(intermediate) layer are Na, Al, Si, K, Zn, Zr and Ce. The intermediate layer formed by the 2nd firing is more larger than the intermediate layer formed by the 1st firing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.676-677
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• 2011

Rhenium-Iridium(Re-Ir) thin films were deposited onto the tungsten carbide(WC) molding core by sputtering system. The Re-Ir thin films on tungsten carbide molding core were analyzed by scanning electron microscope(SEM) and surface roughness. The Re-Ir coating technique has been intensive efforts in the field of coating process because the coating technique and process have been their feature, like hardness, high elasticity, adrasion resistance and mechanical stability and also have been applied widely the industrial and biomedical areas. In this report, tungsten carbide(WC) molding core was manufactures using high performance precision machining and the efforts of Re-Ir coating on the surface roughness.