• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.571-580
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• 2016

In this paper, performance of the gas turbine combined cycle(GTCC) using pre-combustion carbon capture technology was comparatively analysed. Steam reforming and autothermal reforming were used. In the latter, two different methods were adopted to supply oxygen for the reforming process. One is to extract air form gas turbine compressor (air blowing) and the other is to supply oxygen directly from air separation unit ($O_2$ blowing). To separate $CO_2$ from the reformed gas, the chemical absorption system using MEA solution was used. The net cycle efficiency of the system adopting $O_2$ blown autothermal reforming was higher than the other two systems. The system using air blown autothermal reforming exhibited the largest net cycle power output. In addition to the performance analysis, the influence of fuel reforming and carbon capture on the operating condition of the gas turbine and the necessity of turbine re-design were investigated.

• 드라이브 ㆍ 컨트롤
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• 제12권3호
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• pp.25-35
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• 2015

The hydraulic power-take-off mechanism (HPTO) is one of the most popular methods in wave energy converters (WECs). However, the conventional HPTO with only one direction motion has a number of drawbacks that limit its power capture capability. This paper proposes an adjustable moving angle wave energy converter (AMAWEC) and investigates the effect of the moving angle on the performance of the wave energy converter to find the optimal moving angle in order to increase the power capture capability as well as energy efficiency. A mathematical model of components from a floating buoy to a hydraulic motor was modeled. A small scale WEC test rig was fabricated to verify the power capture capability and efficiency of the proposed system through experiments.

• 산업기술연구
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• 제39권1호
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• pp.41-45
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• 2019

Hydrogen sulfide ($H_2S$) is mainly produced along with methane and hydrocarbons in many gas fields as well as hydrodesulfurization processes of crude oils containing sulfur compounds and the emission of $H_2S$ has a considerable effect on both environmental problem and human health aspects due to formation of, e.g. acid rain and smog. In recent years, ionic liquids (ILs) have been proposed as the most promising solvents for $CO_2$ and hazardous pollutants capture, such as $H_2S$ and sulfur dioxide ($SO_2$). In this work, we demonstrate the use of the predictive COSMO-SAC model for the prediction of Henry's law constant of $H_2S$ in ILs. Furthermore, the method is used to screen for potential IL candidates for $H_2S$ capture from a set of 2,624 ILs formed from 82 cations and 32 anions. The effects of cation on the Henry's law constant of $H_2S$ such as (i) the variation of the alkyl chain length on cation, (ii) the substituent of methyl group ($-CH_3$) for H in C(2) position and (iii) the change of ring structure for cation family are clearly predicted by COSMO-SAC model.

• 산업공학
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• 제9권3호
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• pp.44-51
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• 1996

The purpose of this paper is to develop a modeling framework for analyzing the effect of price on the PCS (Personal Commununications Service) demand. To achieve this aim, a nonlinear regression model was derived to capture the income effect on the PCS demand and then was combined into an integrated Bass diffusion model. The model was then applied to the emerging PCS market in Korea and the market demands up to the year 2006 were estimated. The results were reviewed and evaluated in various aspects. Finally, the possibilities of model enhancement and model extensions were explored.

• 벤처창업연구
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• 제16권2호
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• pp.123-141
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• 2021

본 연구는 대학생의 창업에 있어 기업가적 태도가 창업기회 인식과 대학생의 창업잠재성에 미치는 영향 관계를 확인하였다. 이에 대학생의 창업잠재성 제고에 영향을 미치는 기업가적 태도 및 창업기회 인식 형성에 유의미한 영향 관계를 확인하고 창업교육과 역할모델에 따른 변수 간 영향 관계를 분석하였다. 연구결과를 요약하면 첫째, 창의성, 리더십, 개인통제는 정보탐색에 유의한 영향을 미치는 것으로 나타났으며, 통찰력과 성취감은 통계적으로 정보탐색에 유의한 영향을 미치지 않는 것으로 나타났다. 둘째, 창의성, 리더십, 통찰력이 정보결합에 유의한 영향을 미치는 것으로 나타났으며, 성취감과 개인통제는 통계적으로 정보결합에 유의한 영향을 미치지 않는 것으로 나타났다. 셋째, 창의성, 리더십, 개인통제는 기회포착에 유의한 영향을 미치는 것으로 나타났으며 통찰력과 성취감은 기회포착에 통계적으로 유의한 영향을 미치지 않는 것으로 나타났다. 넷째, 정보탐색, 기회포착은 인지된 창업가망성에 유의한 영향을 미치는 것으로 나타났으며 정보결합은 통계적으로 인지된 창업가망성에 유의한 영향을 미치지 않는 것으로 나타났다. 다섯째, 정보탐색, 기회포착은 인지된 창업타당성에 유의한 영향을 미치는 것으로 나타났으며 정보결합은 통계적으로 인지된 창업타당성에 유의한 영향을 미치지 않는 것으로 나타났다. 마지막으로 기업가적 태도와 창업기회 인식 간의 관계에서 창업교육프로그램은 유의미한 조절적 역할을 하는 것으로 나타났으며, 창업기회 인식과 창업잠재성 간의 관계에서 역할 모델은 유의미한 역할을 하는 것으로 나타났다. 본 연구는 대학 및 정부 차원에서 지원하고 있는 창업교육 활동의 대상인 대학생의 창업교육과 역할모델 효과에 대해 살펴보고, 창업에 대한 지각된 열망과 지각된 실행가능성이 형성되어야만 창업의도로 이어지기 때문에 바로 창업을 하지 않은 대학생의 창업잠재성관련 시사점을 제언하였다.

• 한국물환경학회지
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• 제27권6호
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• pp.896-904
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• 2011

The features of the capture reaction of $CO_2$ by ammonia solution have been investigated along with the effect of temperature on the reaction based upon computer program-utilizing calculation and thermodynamic estimation. The stable region of $CO{_3}^{2-}$ was observed to increase with temperature and the change of the stable region of $CO{_3}^{2-}$ with temperature was greater than the temperature variation of the stable region of other carbonate species. The distribution diagram for $NH_4{^+}-NH_3$ system was constructed and the rise of temperature resulted in the decrease of the stability of $NH_4{^+}$ ion, which was thought to be due to the endothermic nature of its acidic dissociation. Considering the introduction of $Ca^{2+}$ ion in the carbon capture reaction by $NH_4{^+}$, the temperature was observed to be important in the determination of the order of reaction between carbonate ion and these cations. The removal process of $CO_2$ gas by ammonia solution was presumed to occur in open system and the temperature variations of the concentration of carbonate system species along with their total concentration were calculated for the proper control and design of the real process.

• 감성과학
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• 제25권4호
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• pp.107-118
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• 2022

Human can rapidly detect and deal with dangerous elements in their environment, and they generally manifest as attentional bias toward threat. Past studies have reported that this attentional bias is affected by anxiety level. Other studies, however, have argued that children and adolescents show attentional bias to threatening stimuli, regardless of their anxiety levels. Few studies directly have compared the two age groups in terms of attentional bias to threat, and furthermore, most previous studies have focused on attentional capture and the early stages of attention, without investigating further attentional holding by the stimuli. In this study, we investigated both attentional bias patterns (attentional capture and holding) with respect to negative emotional stimulus in neurotypical adults and adolescents. The effects of anxiety level on attentional bias were also examined. The results obtained for adult participants showed that abrupt onset of a distractor delayed attentional capture to the target, regardless of distractor type (angry or neutral faces), while it had no effect on attention holding. In adolescents, on the other hand, only the angry face distractor resulted in longer reaction time for detecting a target. Regarding anxiety, state anxiety revealed a significant positive correlation with attentional capture to a face distractor in adult participants but not in adolescents. Overall, this is the first study to investigate developmental tendencies of attentional bias to negative facial emotion in both adults and adolescents, providing novel evidence on attentional bias to threats at different ages. Our results can be applied to understanding the attentional mechanisms in people with emotion-related developmental disorders, as well as typical development.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.130-130
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• 2021

The increasing effect of urbanization has been more apparent through flooding and downstream water quality especially from heavy rainfalls. In response, stormwater runoff management solutions have focused on runoff volume reduction and treatment through infiltration. However, there are areas with low infiltration soils or are experiencing more dry days and even drought. In this study, a lab-scale infiltration system was used to compare the applicability of two types of soil as base layer in gravel-filled infiltration systems with emphasis on runoff capture and suspended solids removal. The two types of soils used were sandy soil representing a high infiltration system and clayey soil representing a low infiltration system. Findings showed that infiltration rates increased with the water depth above the gravel-soil interface indicating that the available depth for water storage affects this parameter. Runoff capture in the high infiltration system is more affected by rainfall depth and inflow rates as compared to that in the low infiltration system. Based on runoff capture and pollutant removal analysis, a media depth of at least 0.4 m for high infiltration systems and 1 m for low infiltration systems is required to capture and treat a 10-mm rainfall in Korea. A maximum infiltration rate of 200 mm/h was also found to be ideal to provide enough retention time for pollutant removal. Moreover, it was revealed that low infiltration systems are more susceptible to horizontal flows and that the length of the structure may be more critical that the depth in this condition.

• 분석과학
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• 제36권5호
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• pp.236-249
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• 2023

Carbon dioxide (CO₂) capture and storage is a critical issue for mitigating climate change. Porous aromatic Schiff base complexes have emerged as a promising class of materials for CO₂ capture due to their high surface area, porosity, and stability. In this study, we investigate the potential of Schiff base complexes as an effective media for CO₂ storage. We review the synthesis and characterization of porous aromatic Schiff bases materials complexes and examine their CO₂ sorption properties. We find that Schiff base complexes exhibit high CO₂ adsorption capacity and selectivity, making them a promising candidate for use in carbon capture applications. Moreover, we investigate the effect of various parameters such as temperature, and pressure on the CO₂ adsorption properties of Schiff base complexes. The Schiff bases possessed tiny Brunauer-Emmett-Teller surface areas (4.7-19.4 m²/g), typical pore diameters of 12.8-29.43 nm, and pore volumes ranging from 0.02-0.073 cm³/g. Overall, our results suggest that synthesized complexes have great potential as an effective media for CO₂ storage, which could significantly reduce greenhouse gas emissions and contribute to mitigating climate change. The study provides valuable insights into the design of novel materials for CO₂ capture and storage, which is a critical area of research for achieving a sustainable future.

• 한국방사선학회논문지
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• 제6권5호
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• pp.403-408
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• 2012

본 연구는 천연 인듐의 중성자폭획 후에 발생된 감마선을 12개의 BGO($Bi_4Ge_3O_{12}$) 섬광검출기로 구성된 검출장치를 이용하여 즉발감마선을 측정하여 중성자공명에 의해서 발생된 감마선을 분석하여 중성자의 에너지 1 ~ 300 eV 영역에 대하여 공명에너지를 분석하였다. 사용되어진 검출장치는 시료에서 발생된 즉발감마선에 대하여 모든 감마선을 측정할 수 있는 기하학적인 구조로 만들어졌다. 중성자원으로는 교토대학의 원자로연구소의 46-MeV 전자선형가속기의 광핵반응에서 발생하는 중성자를 이용하였다. 중성자발생원으로부터 검출기까지의 거리가 $12.7{\pm}0.02m$이므로 광핵반응에서 발생하는 강한 X선의 영향을 고려하여 수 keV영역이하의 중성자에너지에 대하여 중성자공명을 측정하였다. 측정되어진 공명들은 1 eV이상의 에너지 영역에서 거대 공명들을 측정하였고 이들 공명들은 이론에서 알려진 값들과 비교하였다. 본 연구를 통하여 기존에 알려진 거대 공명의 에너지를 확인하였고, 100 eV이상의 에너지 영역에서의 공명에너지들에 대한 평가에 의한 이론값들이 실제로 존재하는 공명임을 실험적으로 확인하였다. 1 keV 이상의 영역에 대하여는 공명이 연속적인 구조를 보이고 있음을 실험적으로 확인했으며 공명에 대하여 통계적인 평가가 있어야함을 알았다. 91.49 eV 공명은 본 연구를 통하여 처음 발견되어진 공명이라 볼 수 있다.