• Proceedings of the Materials Research Society of Korea Conference
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• 2008.11a
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• pp.12.1-12.1
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• 2008

• Journal of the Korean Chemical Society
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• v.46 no.1
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• pp.69-75
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• 2002

The $Y_{1-x}(P_{1-y-z}Nb_yV_z)O_4:Eu_x$ blue and red emitting phosphors were prepared by the combinatorial chemistry method. The combinatorial library was designed to investigate the luminescence of the $Y_{1-x}(P_{1-y-z}Nb_yV_z)O_4:Eu_x$ phosphors under 254 nm and 147 nm excitations. In addition, the crystallinity and morphology of phosphors were checked by XRD and SEM. Based on the results from the combinatorial screenings, luminescent properties of phosphors are strongly dependent on the concentration of doping metal ions. It was found that a new phosphor $Y_{0.88}(P_{0.92}Nb_{0.05}V_{0.03})O_4:Eu_{0.12}$ shows excellent luminescent efficiency comparing to the $Y_{0.88}PO_4:Eu_{0.12}$ red phosphor.

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.357-365
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• 2010

Combinatorial synthesis, which has been adopted as an efficient method for deriving a leading compound in pharmaceutical chemistry, is recently being applied in various fields along with the rapid development of analysis and examination technology. It is especially attracting much attention as an efficient strategy to secure various potent compounds rapidly in the areas of developing new materials where the relationship between the chemical structure and the property is not revealed. Several reports and reviews have already been published for the combinatorial chemistry and combinatorial synthesis. This report briefly introduces trends in the combinatorial development of new materials and discusses the cases of developing organic luminescent materials.

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.10a
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• pp.29-29
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• 1997

화학반응 또는 화학증착분야에 주로 이용해 오던 유도플라즈마를 이용하여 고밀도의 두꺼운 세라믹 침적물을 제조하였다. Yttria Stabilized Zirconia 분말을 이용하여 최적조건에서 두께 약 5mm, 이론밀도 90% 이상의 침적물을 얻었다. 실험변수는 플라즈마 가스조성, 플라즈마동력, 입자의 크기, 용사거리 등으로 하였으며, 각각의 실험조건에서 용사된 spherodized particle을 수집하여 각 실험조건에서 용융된 입자의 상태를 비교하였다. 또, 침적물의 표면을 에칭시켜 각 실험조건에서의 침적상태를 관찰 및 비교하여 각각의 실험변수가 침적물의 밀도에 미치는 영향을 관찰하였다. 실험결과 높은 밀도의 침적물을 만들기 위해서는 분말의 용융상태, 용사챔버 내부압력, 분말분사거리가 중요한 변수임을 알 수 있었다. 실험에서 얻어진 결과는 ANOVA 통계기법으로 분석하여 단일변수의 영향뿐만 아니라 이들 영향이 서로 조합하여 결과에 미치는 조합효과도 분석하였다.

• Journal of the Korean Ceramic Society
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• v.41 no.5
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• pp.381-387
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• 2004

Recently developed Plasma Display Panels (PDP) require phosphors of high luminance at Vacuum Ultraviolet (VUV) excitation. The present investigation developed new PDP phosphors using combinatorial chemistry method. We applied T $b^{3+}$ -activated yttrium gadolinium phosphates system to our combinatorial fine-tuning technique. As a result, the optimum composition was determined to be (G $d_{0.74}$ $Y_{0.11}$T $b_{0.15}$) $P_{1.15}$ $O_{\delta}$ through the two-step combinatorial screening process including excess phosphorous and Gd replacement. We found that the sample of the optimum composition shows a higher luminescence efficiency at VUV excitation and a shorter decay time than the commercially available Z $n_2$ $SiO_4$:Mn phosphor.

• Journal of the Korean Institute of Gas
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• v.23 no.3
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• pp.33-39
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• 2019

in 2010s, many factories are operating without any safety guarantees due to the aging process. Although it is difficult to fundamentally solve the problem of aging process and equipment, Prevent risk by risk assessment in advance. This study targets the corrosion caused by sulfur in the piping in the CDU(Crude Distillation Unit) process desulfurization equipment and conducts the risk assessment by RBI(Risk Based Inspection) referring to API RP 581. RBI expresses the risk by combining frequency and consequence, and creates a risk matrix based on these expression. In this study, the hole size of the pipe was selected as Small and Medium, and the sensitivity of the frequency was selected as 'Low'. You can refer to the Risk Matrix created from the standard to evaluate the risk of corrosion of sulfur from pipes in the piping and to plan future accident prevention. Similarly, prevention of aging in a similar way can prevent large and small incidents that are not visible.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.85-89
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• 2019

Cell-free protein synthesis utilizes the translational machinery in a cell extract. Unlike the conventional cell-based expression methods, not being affected by the conditions for cell growth, cell-free protein synthesis enables flexible manipulation of individual factors affecting the efficiency protein biosynthesis. However, the high cost and low stability of the energy sources to regenerate ATP have limited the use of cell-free synthesis for large-scale production of recombinant proteins. One of the approaches to address this problem is to use glucose as an alternative energy source to regenerate ATP through the glucose-metabolizing pathways in a cell extract. In this study, in an attempt to improve the efficiency of ATP regeneration by reinforcing oxidative phosphorylation process, we supplemented with cellular lipids to a glucose-fueled reaction mixture for cell-free protein synthesis. As a result of the lipid supplementation, the productivity of chloramphenicol acetyltransferase in a cell-free synthesis system using glucose increased more than 6 fold compared to when the lipid was not supplemented.

• Journal of the Korean Chemical Society
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• v.45 no.6
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• pp.577-588
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• 2001

Eu doped YRO$_4$ (R=As, Nb, P, V) red phosphors were prepared by the combinatorial chemistry method. The quaternary material library of tetrahedron-type composition array was designed to investigate the luminescence of the host material under UV and VUV excitations (254, 147 nm). The photoluminescent characteristics of the samples were comparable to the commercially available red phosphors such as (Y, Gd)BO$_3$: $Eu^{3+}$ and Y$_2$O$_3$: In view of the luminescence yield, V rich region was found to be optimum under UV excitation. But the results under VUV excitation were different from those of UV excitation, the samples of the composition containing a large amount of P shows the highest luminescence. Especially, higher luminescence was obtained in $Y_{0.9}$(A$S_{0.06}$N$B_{0.06}P_{0.83}V_{0.06}$) O$_4$: $Eu_{0.1}$ phosphors than commercial (Y, Gd)BO$_3$red phosphors under 147 nm excitation.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2000.04a
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• pp.1-2
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• 2000

일반적인 신약 개발 방법으로는 천연물로부터 선도화합물이 발견되었을 때 의약화학자들은 그 물질의 화학구조식 중에서 약리 작용에 필수 요건이 되는 구조 요소를 규정하고, 체계적인 분자변형을 통하여 약리 작용의 최적화 작업을 추진한다. 그러나 분자 내에 여러 가지 치환기를 도입할 수 있는 경우 수많은 유도체가 합성 가능하며, 실제로 이와 같은 많은 수의 유도체를 합성한다는 것은 현실적으로 불가능하다. 통계적으로 하나의 신약 개발에 드는 시간과 경비는 약 10년 이상의 기간과 3,000 억원 이상의 경비가 소요된다. 따라서 시간과 경비를 줄이는 노력의 하나로 실험분야에서는 조합 화학합성 (Combinatorial Chemical Synthesis, CCS) 기술인 새로운 개념의 고효율 합성 기술이나 이를 대량 검색할 수 있는 초고속 활성 검색법 (High Through-put Screening, HTS) 기술이 1990년대 초에 본격적으로 각광 받게되었고, 정보관리 시스템을 통한 library 구축, 컴퓨터를 이용한 구조-활성 관계 및 분자 설계 기법이 급속히 발전하게 되었다. 따라서 기존의 random screening에 의한 신약개발 방법으로부터 탈피하여 새로운 차원의 신의약 개발 방법의 필요성이 절실히 요구되고 있다.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.6
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• pp.72-83
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• 2018

In this study, a series of CFD analyses were carried out for a hydrogen rocket combustor with a single shear coaxial injector. A hybrid RANS/LES approach was used for the turbulent combustion analysis with a two-dimensional axisymmetric configuration. Three reaction mechanisms, three spatial discretization methods, and three levels of grid resolution were compared to determine an appropriate CFD approach. The performance of the CFD prediction were investigated by comparing the wall heat flux with experimental data. Investigation of the flow field results provides an insight into the characteristics of the turbulent reacting flow of a rocket combustor with a shear coaxial injector.