• Journal of the Korean Vacuum Society
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• v.4 no.2
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• pp.150-155
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• 1995

Mo 단결정 표면에 황을 흡착시켜 형성된 상층구조를 AES와 LEED로써 연구하였다. 황의 피복률은 sulfur gun으로부터 생성되는 S2 flux로써 조절하였으며, 여러 가지 흡착된 황의 상층구조를 LEED로써 관찰하였다. 황화된 Mo 표면에서 탈산소반응(HDO)의 모델 분자로서, Furan의 흡착과 반응을 승온반응분광법(TPRS)으로 조사하였다. 낮은 온도에서 Furan 분자의 헤테로 원자는 직접 이탈하여 안정한 기체상의 반응 생성물인 일산화탄소를 형성하였으며, 이 반응은 Mo의 (100) 및 (110)면에서 각각 깨끗한 표면 및 황화된 표면에 관계없이 일어났다. 이를 바탕으로 Mo 표면에서 Furan의 분해반응에 대한 메카니즘을 제안하였다.

• Analytical Science and Technology
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• v.7 no.2
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• pp.187-191
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• 1994

A reactive intermediate 1,2-dihydropyridine derivative 2 has been prepared and isolated from the reaction of pyridine with $^tBuLi$ and trimethylchlorosilane in nonpolar condition at low temperature 2 has characterized by $^1H-NMR$ fine structure analysis with SPINX3. The mechanistic information of formation of 2 was obtained from synthesized 2,5-disubstituted pyridine derivatives 3 and 4.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.3
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• pp.255-264
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• 2019

Endodontic treatment of primary molars is a great challenge to the dentists because of their complex morphology. However, there have been limited controlled in vivo studies about filling materials for primary teeth. Hence, the aim of this study is to evaluate and compare histologic responses of different calcium hydroxide canal filling materials that are used in daily clinical practice. Pulpectomies were performed in 132 teeth of the dogs. The root canals were randomly filled with either $Vitapex^{(R)}$ (n = 44), $Metapex^{(R)}$ (n = 44), or $Metapaste^{(R)}$ (n = 44). After 4 or 13 weeks, respectively after operation, the dogs were sacrificed, and teeth were processed for histologic examinations. Inflammatory reaction was evaluated and scored in a blind manner. The Fisher's exact test and Kruskal-Wallis test were used to compare the tested groups. In 4-week-group, all inflammatory responses were in normal range except for fibrosis. In 13-week-group, increased response to various inflammation reaction was shown compared to the 4-week-group. However, there were no statically significant differences between the tested groups in all inflammatory reaction. Overall, there were no significant differences among three materials in responses of apical tissues and all of them showed favorable tissue responses.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.100-115
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• 2022

In this study, integrated hybrid system (IHS) composed of two alternatively-operating UV/photocatalytic reactor (AOPR) process and biofilter processes of a biofilter system having two units (i.e., R_up and R_dn) with an improved design (R reactor) and a conventional biofilter (L reactor) was constructed, and its transient behavior was observed to perform the successful treatment of waste air containing ethanol and hydrogen sulfide (H₂S). At the IHS-operating stages of HA1, HA2 and HA3T of reversed feed direction, the AOPR process showed not only ethanol-removal efficiencies of 55, 50 and 45%, respectively, but also H₂S-removal efficiencies of 70, 60 and 37%, respectively. In particular, a drastic decrease of H₂S-removal efficiency at the stage of HA3T was observed due to a doubling of H₂S-inlet concentration fed to AOPR from 10 ppmv to 20 ppmv at the stage of HA3T. The order of ethanol-breakthroughs and the order of the magnitude of ethanol-removal efficiencies at the sampling ports of each unit of R reactor at the stages of HA1, HB1, HA2, HB2, and the first half of HA3T, were reversed, respectively, at the stages of the second half of HA3T and HB3T. In case of H₂S, R reactor did not show H₂S-breakthrough as prominent as the ethanol-breakthrough, but showed the trend similar to the ethanol-breakthrough.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.279-287
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• 2005

This study was carried out to investigate resumption of ovarian cyclicity and effect of BCS on estrous response by treatment of $PGF_2a+PGF_2a+CIDR$ program on day 40 postpartum in lactating dairy cow. First $PGF_2a$ was given on day 40 postpartum, second $PGF_2a$ was given 14 days apart to cows not-responded to 1st $PGF_2a$ and then CIDR was inserted for 7 days after 5 days in cows not-responded to 2nd $PGF_2a$. The $42.9\%$ of the cows showed more than 1 ng/mL milk progesterone concentration within 10 to 30 days postpartum. About $19\%$ of the cows exhibited more than 1 ng/mL milk pro-gesterone concentration between 31 to 50 days postpartum. However $38.1\%$ of the cows have not shown more than 1 ng/mL milk progesterone up to 50 days postpartum. Estrous response to the treatment of 1 st $PGF_2a$ and 2nd $PGF_2a$ was $47.5\%$ and $52.4\%$, respectively. Combination of 1 st $PGF_2a$ and 2nd $PGF_2a$ was $75\%$ and combination of 1st $PGF_2a$+2nd $PGF_2a$+CIDR was $87.5\%$. Estrous response to the treatment of $PGF_2a+PGF_2a$ program was $61.5\%$ in cows with less than 2.50 BCS and $81.5\%$ in cows with 2.75${\~}$3.50 BCS. Estrous response to the treatment of CIDR was $40\%$ in cows with less than 2.50 BCS and $80\%$ in cows with 2.75${\~}$3.50 BCS. Estrous response to the treatment of PPC on day 40 postpartum was $76.9\%$ in cows with less than 2.50 BCS and $96.3\%$ in cows with 2.75${\~}$3.50 BCS.

• Journal of the Korean Chemical Society
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• v.44 no.1
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• pp.30-36
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• 2000

Upon Pd(0)-catalyzed coupling reaction of (2R)-2-(N,N-ditosylimido)-3-butenyl methyl malonate (4) which was selected for the total synthesis of A-factor, (3R)-2-(6-methylheptanoyl)-3-hydroxy methyl-4-buttinolide (1), an unexpected 14-membered cyclic compound, bis(2-methoxycabonyl-(4E)-hexenolide) (15) was obtained. The structure of this compound was conformed by X-ray crystallography. This result implies that this method can be applied the synthesis of various size of symmetrical macrocyclic compounds.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.3
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• pp.287-293
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• 2010

In this study, the toluene gas in VOCs was removed using bioreactor which applied with hollow fiber membrane and Pseudomonas sp. TDB-4. The EBRT of each reactor are controlled 60 sec(R-1) and 30 sec(R-2) and inlet tolune concentration of both R-1 and R-2 is controlled from 25ppm to 500 ppm. Up to 500 ppm of toluene concentration, the toluene removal efficiency of R-1 and R-2 are 92% and 81%, and theirs removal capacities are about 100 g/$m^3$/hr and 180 g/$m^3$/hr, respectively. In addition, according to this study, toluene removal efficiencies at the hollow fiber are approximately 70%(60 sec) and 45%(30sec).

• Journal of Energy Engineering
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• v.6 no.1
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• pp.34-40
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• 1997

This study aims to investigate the application possibility on natural gas in relation to the catalytic combustion of methane on Pd/cordierite catalyst which is currently used as an automobile converter catalyst. The surface area of the catalyst tested was determined to be about 18.7㎡/g and to keep stable condition in structure at mid-high temperatures. The activation energy for methane combustion reaction was estimated to be 19.2 kcal/mol and a hysterisis on the catalyst activity was observed in terms of the catalyst deactivation as the reaction temperature was varied for the methane combustion. On Pd/cordierite catalyst, The characteristics of methane combustion were studied as functions of space velocity and air/fuel ratios below 700$^{\circ}C$.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.1
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• pp.17-22
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• 1984

The author carried out an experiment to find on the optomotor response of crusian carp, Carassius carassius and goldfish, Carassius auratus in accordance with the colors of the wall and the stripes labeled on the revolving visual screen. The results are as follows; 1. The optomotor response rate of crusian carp was 80% or more in case of B-Y, R-Bl and W-Bl pair of colors, and 50% or less in case of Bl-B, B-Bl, R-W, R-Y, W-Y and Y-W pair. 2. The optomotor response rate of goldfish was 80% or more in all except B-Bl, W-R and W-Y pair. 3. Mean round number of crusian carp was 7.5-9.5 revolutions in case of W-Bl, Y-Bl, W-B and Y-B pair, and 1.8-3.9 revolutions in case of Bl-B, Bl-Y, B-Bl, B-R, R-All and Y-W pair for 3 minutes. 4. Mean rounded number of goldfish was only 4.1-4.9 revolutions in case of W-Bl, W-B and Y-B pair for 3 minutes.

• Clean Technology
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• v.24 no.1
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• pp.63-69
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• 2018

The reduction reaction characteristics and physicochemical properties were studied for the selection of oxygen carrier, which is the core of the chemical looping combustion (CLC) technology. Fuel conversion and $CO_2$ selectivity of oxygen carrier according to the concentration of reducing gas and the reduction temperature using three kinds of oxygen carrier (SDN70, N018-R2, N016-R4) were measured and compared. In addition, Attrition Index (AI) and BET surface area were measured to analyze the attrition resistance and the surface characteristics of the oxygen carrier. As a result, it was confirmed that all three kinds of oxygen carrier were suitable for use in chemical roofing combustion system, and the best particle was determined to be N016-R4.