• 한국진공학회지
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• 제15권5호
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• pp.485-492
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• 2006

새로운 1가 구리 전구체인 $[Cu^I(hfac)]_2(DVTMSO)$ and $[Cu^I(hfac)]_2(HD)$ (hfac=hexa- fluoroacetylacetonate, DVTMSO=1,2-divinyltetramethyldisiloxane, HD=1,5-hexadiene)를 합성하였으며, 또한 유기금속 화학증착법을 사용하여 증착특성을 확인하였다. 새로운 전구체는 기존 구리 1가 전구체와는 다르게 두 개의 Cu(hfac)가 하나의 중성리간드에 결합된 형태를 가지고 있다. 또한 새롭게 합성된 두 종류의 전구체는 기존에 알려진 1가 구리 고체 전구체에 비해 높은 안정성 및 높은 증기압을 가지고 있는 것이 확인하였다. 아울러 기존의 전구체와는 달리 새로운 전구체로 화학증착하면 막 (films)을 형성하지 않고 구리점 (dots)을 형성하는 것을 확인하였으며 이는 새로운 구조로부터 기인된 현상이라고 생각된다. 구리점의 모양은 증착온도에 따라 급격하게 변하는 것도 관찰되었다.

• Carbon letters
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• 제25권
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• pp.95-102
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• 2018

We examined the pressure effects on petroleum pitch synthesis by using open and closed reaction systems. The pressure effects that occur during the pitch synthesis were investigated in three pressure systems: a closed system of high pressure and two open systems under either an atmosphere or vacuum. A thermal reaction in the closed system led to the high product yield of a pitch by suppressing the release of light components in pyrolysis fuel oil. Atmospheric treatment mainly enhanced the polymerization degree of the pitch via condensation and a polymerization reaction. Vacuum treatment results in a softening point increase due to the removal of components with low molecular weights. To utilize such characteristic effects of system pressure during pitch preparations, we proposed a method for synthesizing cost-competitive pitch precursors for carbon materials. The first step is to increase product yield by using a closed system; the second step is to increase the degree of polymerization toward the desired molecular distribution, followed by the use of vacuum treatment to adjust softening points. Thus, we obtained an experimental quinoline insolubles-free pitch of product yield over 45% with softening points of approximately $130^{\circ}C$. The proposed method shows the possibility to prepare cost-competitive pitch precursors for carbon materials by enhancing product yield and other properties.

• 한국식품과학회지
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• 제38권5호
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• pp.621-627
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• 2006

압출성형에 의해 제조된 구운 쇠고기 반응향의 향특성을 알아보기 위해 휘발성 성분 및 aroma-active화합물을 SDE-GC-MS-O법을 이용하여 분석하였다. HVP에 ribose, cysteine, furaneol, thiamin, methionine, 마늘 분말 및 인지질 등의 전구문질을 넣고 최적 압출성형 조건인 $160^{\circ}C$, 스크루 속도 45 rpm 및 윈료공급 속도 38 kg/hr에서 압출성형하였다. 압출성형에 의해 제조된 구운 쇠고기 반응향에서 모두 68개 의 휘발성 성분이 검출되었으며, 그 숫자는 furaneol을 빼고 압출성형 시킨 반응향과 HVP만 압출성형 시킨 시료에서 크게 줄어들었다. GC-O결과 구운 쇠고기 반응향에서 27개의 aroma-active 화합물이 검출되었으며, methional과 2-methyl-3-furanthiol이 가장 중요한 aroma-active화합물로 밝혀졌다. Furaneol이 구운 쇠고기 반응향 생성에 있어서 중요한 역할을 할 것으로 생각되어 진다.

• 상하수도학회지
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• 제25권2호
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• pp.223-230
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• 2011

An electrolytic oxidation process was applied to remove odorous compounds from non-point odor sources including wastewater pipelines and manholes. In this study, a distance between the anode and the cathode of the electrolytic process was varied as a system operating parameters, and its effects on odor removal efficiencies and reaction characteristics were investigated. Odor precursors such as sediment organic matters and reduced sulfur/nitrogen compounds were effectively oxidized in the electrolytic process, and a change in oxidation-reduction potential (ORP) indicated that an stringent anaerobic condition shifted to a mild anoxic condition rapidly. At an electrode distance of 1 cm and an applied voltage of 30 V, a system current was maintained at 1 A, and the current density was 23.1 $mA/cm^{2}$. Under the condition, the removal efficiency of hydrogen sulfide in gas phase was found to be 100%, and 93% of ammonium ion was removed from the liquid phase during the 120 minute operating period. Moreover, the sulfate ion (${SO_4}^{2-}$) concentration increased about three times from its initial value due to the active oxidation. As the specific power consumption (i.e., the energy input normalized by the effective volume) increased, the oxidation progressed rapidly, however, the oxidation rate was varied depending on target compounds. Consequently, a threshold power consumption for each odorous compound needs to be experimentally determined for an effective application of the electrolytic oxidation.

• 한국식품과학회지
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• 제35권6호
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• pp.1045-1052
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• 2003

HVP로부터 구운 쇠고기향를 제조하기 위하여 쇠고기향 생성에 중요하게 작용하는 반응들을 고려하여 전구물질을 탐색한 결과, 구운 소고기 향을 생성하는 전구물질조성으로 HVP, ribose, cysteine, furaneol, thiamin, methionine, 마늘분말 및 phospholipid를 선정 하였다. 선정된 전구물질조성을 고온 고압 반응기를 이용하여 구운 쇠고기향 생성에 영향을 주는 반응조건들을 알아본 결과, 최적 반응조건은 $130^{\circ}C$, 교반속도 100rpm 및 반응시간 1시간에 수분 7.5% 첨가시 좋은 구운 쇠고기 향이 생성되었다. Omission test에 의해 구운 쇠고기향 생성에 중요한 역할을 하는 전구물질을 선정한 결과 cysteine, furaneol, thiamin 및 마늘분말이었다. HVP 5% ribose, 5% methionine, 5% phospholipid를 기본 base로 하고, cysteine, furaneol, thiamin, 그리고 마늘분말을 독립변수로 하여 반응표면분석법을 행한 결과 전구물질의 최적조성은 7.7% cysteine, 7.3% furaneol, 2.1% thiamin 및 6.9% 마늘 분말로 나타났다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.132-132
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• 2011

For the programming volume of PRAM, Ge2Sb2Te5(GST) thin films have been dominantly used and prepared by physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD). Among these methods, ALD is particularly considered as the most promising technique for the integration of PRAM because the ALD offers a superior conformality to PVD and CVD methods and a digital thickness control precisely to the atomic level since the film is deposited one atomic layer at a time. Meanwhile, although the IST has been already known as an optical data storage material, recently, it is known that the IST benefits multistate switching behavior, meaning that the IST-PRAM can be used for mutli-level coding, which is quite different and unique performance compared with the GST-PRAM. Therefore, it is necessary to investigate a possibility of the IST materials for the application of PRAM. So far there are many attempts to deposit the IST with MOCVD and PVD. However, it has not been reported that the IST can be deposited with the ALD method since the ALD reaction mechanism of metal organic precursors and the deposition parameters related with the ALD window are rarely known. Therefore, the main aim of this work is to demonstrate the ALD process for IST films with various precursors and the conformal filling of a nano size programming volume structure with the ALD?IST film for the integration. InSbTe (IST) thin films were deposited by ALD method with different precursors and deposition parameters and demonstrated conformal filling of the nano size programmable volume of cell structure for the integration of phase change random access memory (PRAM). The deposition rate and incubation time are 1.98 A/cycle and 25 cycle, respectively. The complete filling of nano size volume will be useful to fabricate the bottom contact type PRAM.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.71-71
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• 2012

As the critical dimensions of integrated circuits are scaled down, the line width and spacing between the metal interconnects are made smaller. The dielectric film used as insulation between the metal lines contributes to the resistance-capacitance (RC) time constant that governs the device speed. If the RC time delay, cross talk and lowering the power dissipation are to be reduced, the intermetal dielectric (IMD) films should have a low dielectric constant. The introduction of Cu and low-k dielectrics has incrementally improved the situation as compared to the conventional $Al/SiO_2$ technology by reducing both the resistivity and the capacitance between interconnects. Some of the potential candidate materials to be used as an ILD are organic and inorganic precursors such as hydrogensilsequioxane (HSQ), silsesquioxane (SSQ), methylsilsisequioxane (MSQ) and carbon doped silicon oxide (SiOCH), It has been shown that organic functional groups can dramatically decrease dielectric constant by increasing the free volume of films. Recently, various inorganic precursors have been used to prepare the SiOCH films. The k value of the material depends on the number of $CH_3$ groups built into the structure since they lower both polarity and density of the material by steric hindrance, which the replacement of Si-O bonds with Si-$CH_3$ (methyl group) bonds causes bulk porosity due to the formation of nano-sized voids within the silicon oxide matrix. In this talk, we will be introduce some properties of SiOC(-H) thin films deposited with the dimethyldimethoxysilane (DMDMS: $C_4H_{12}O_2Si$) and oxygen as precursors by using plasma-enhanced chemical vapor deposition with and without ultraviolet (UV) irradiation.

• 한국식품영양학회지
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• 제28권6호
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• pp.1019-1025
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• 2015

The influence of aging on the flavor precursors and volatile compounds of top round beef was studied. The concentrations of free amino acids, nucleotides, creatine, dipeptides, and volatile compounds were measured after top round from Hanwoo was aged at $4^{\circ}C$ for 21 days. The amount of free amino acids in top round significantly increased with the increase of aging period. There was no effect of aging on the concentrations of adenosine monophosphate or inosine in top round. The inosine monophosphate content of top round significantly decreased with age, while the hypoxanthine content increased. The concentrations of creatine, carnosine, and anserine in top round were not influenced by aging. In total, 24 volatile compound were identified in aged, cooked top round. Of these, the quantities of aldehydes (propanal, pentanal, hexanal, heptanal, octanal, and nonanal), hydrocarbons (pentane and octane), 2-butanone, ethyl acetate, and pyridines (4-ethynyl-pyridine and 4-acetyl-pyridine) significantly increased after aging. We conclude that the flavor of top round can be improved by aging.

• 한국전기전자재료학회논문지
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• 제13권4호
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• pp.349-358
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• 2000

Fabrication and Characterization of Bi$_{2}$/Sr$_{2}$/CaCu$_{2}$/O$_{8}$(Bi2212) superconductor thick films were fabricated successfully on C tapes by liquid reaction between Cu-free precursors of Bi$_{x}$/SrCaO/$_{y}$(x=1.2-2) and Cu tapes. Cu-free Bi-Sr-Ca-O powder mixtures were screen-printed on Cu tapes and heat-treated at 850-87$0^{\circ}C$ for several minutes in air oxygen nitrogen and low oxygen pressure. In order to obtain the optimum heat-treatment condition we studied the effect of the precursor composition the printing thickness and the heat-treatment atmosphere on the superconducting properties of Bi2212 films and the reaction mechanism. Microstructures and phases of thick films were analyzed by films and the reaction mechanism. Microstructures and phases of thick films were analyzed by optical microscope and XRD. The electric properties of superonducting films were examined by the four probe method. At heat-treatment temperature the thick films were in a partially molten state by liquid reaction between CuO of the oxidized copper tape and the precursors which were printed on Cu tapes. During the heat-treatment procedure Bi2212 superconducting particle nucleate and grow in preferred orientations.ons.s.

• International Journal of Oral Biology
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• 제30권4호
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• pp.143-148
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• 2005

Osteoclasts are multinucleated cells with bone resorbing activity and differentiated from hematopoietic cell lineages of monocyte/macrophages in the presence of receptor activator of NF-${\kappa}B$ ligand (RANKL) and M-CSF. However, the exact molecular mechanisms through which RANKL stimulates osteoclastogenesis remain to be elucidated. Here we report that activation of cAMP-response elementbinding protein (CREB) is not involved in osteoclastogenesis from osteoclast precursors in response to RANKL. RANKL induced CREB activation in osteoclast precursors. Using pharmacological inhibitors, we found that RANKL-induced CREB activation is dependent on p38 MAPK pathways. We also found that ectopic expressions of wild type and dominant negative forms of CREB in osteoclast precursors did not affect RANKL-induced osteoclast formation and bone resorbing activity. Furthermore, dominant negative forms of CREB did not alter the expression levels of osteoclast-specific marker genes. Taken together, these data suggest that CREB is dispensable for differentiation and resorbing activity of osteoclasts.