• Journal of Korean Society for Atmospheric Environment
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• v.24 no.4
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• pp.415-422
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• 2008

This study was carried out to investigate the effect of operating and design conditions of gas dispersion type of absorber on $SO_2$ removal efficiency. pH difference between upper and lower part of gas dispersing plate of absorber was 0.2, which was relatively low. This was supposed that recirculation capacity of absorbing liquid between froth zone and reaction zone of absorber be increased by oxidation air injection through liquid riser which acted as liquid pump. Test results showed that $SO_2$ removal efficiency was more sensitive than absorber ${\Delta}P$. High $SO_2$ removal even at lower pH resulted from very low concentration of $HSO_3^-$ ion in absorbing liquid because of direct supply of dissolved oxygen into froth zone. 96% of $SO_2$ removal efficiency was obtained under the condition of absorber pH 5.2, flue gas flow rate of $1,530\;Nm^3/hr$, inlet $SO_2$ concentration of 800 ppm, absorber ${\Delta}P$ of 250mmAq. The following equation by a multiple linear regression was obtained to describe the relationship between $SO_2$ removal and operating variables. $$f=1-{\exp}(-1.3939+1.060pH+0.0139{\Delta}P-0.00267G-0.000064SO_2Conc.),\;R^2=0.9719$$

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.E4
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• pp.157-162
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• 2001

Jet Bubbling Reactors(JBRs) were operated for the removal of SO$_{x}$ in flue gases produced from many electric power plants. However, many JBR flue gas desulfurization (FGD) facility faced a decrease of SO$_{x}$ removal efficiency and an increase of scale problems with continuous operations. We increased alkalinity of the SO$_{2}$ absorbing medium by adding the dibasic acids (DBAs) to solve these problems more effectively. The SO$_{2}$ removal efficiency, the purity of CaCO$_{3}$ and COD of the wastewater was measured to identify the addition effects of DBAs (150, 200, 250, and 400 ppm) for 2hr in a day into the JBR attached to the large-scale power plants (400 MW$\times$3). Addition of the DBAs resulted in the improvement of the SO$_{2}$ removal efficiency from 2 to 5% and the purity of the gypsum from 1 to 2%; these improvement were due to the alkalinity increase of the absorbing medium and the reduction of a proportion of un-reacted CaCO$_{3}$, respectively. Also, the scale problems formed by un-reacted CaCO$_{3}$ inside the reaction zone of the JBR were substantially reduced. Even though the effluent COD of the wastewater slightly increased from 10~15 to 18~36 mg/l and the erosion problems in the injection pump and duct occurred, this method of increasing SO$_{2}$ removal efficiency by adding the DBAs could be considered as a profitable approach.ach.

• Corrosion Science and Technology
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• v.7 no.5
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• pp.269-273
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• 2008

It is known that the fluoric resin has the most outstanding properties in the extremely acidic environment of high temperature. However, this resin is the thermal hardening type that needs long time heat treatments above $250^{\circ}C$. It's impossible to use in situ in the extremely acidic environment such as a huge FGD ductworks or industrial chemical tanks. Furthermore, even the natural hardening type fluoric coatings which can be hardened less than $120^{\circ}C$ can not be applied to the highly acidic environmental plants because of its chemical resistance. In this study, new fluoric coatings that has excellent thermal resistance, chemical resistance and corrosion resistance has been developed in order to solve above problems and to be applied to the large plant structures in the field. These newly developed coatings are organic and inorganic composite type that have fluoric rubber(100 wt%), fluoric resin(5~50 wt%), oxalates(5~30 wt%), inorganic fillers mixed with plate-type and bulk-type solids(20~150 wt%), hardeners(0.5~5 wt%), and hardening hasteners(0.1~3 wt%). The best chemical and physical properties of these coatings are acquired by variation of adhesive reinforcement agents, dispersants, leveling agents. Mixing ratios of plate-type and bulk-type inorganic fillers influence the thermal properties, abrasive resistance and chemical infiltration properties of coatings. The mixing control is also very important to have homogeneous surface and removing inner voids of coatings.

• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.281-291
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• 2017

Emotional interaction in virtual reality is necessary of social communication. However, social emotion has been tried to be less recognized quantitatively. This study was to determined social gaze of emotion in business domain. 417 emotion words were collected and 16 emotion words were selected to Goodness of Fit. Emotion word were mapped into 2 dimensional space through multidimensional scaling analysis. Then, X axis defined dimensions of cooperation, competition, and Y axis of low focus and high focus through the FGD. 52 subjects were presented to stimuli for emotion and gaze movement data were collected. Independent t-test results showed that the gaze factor increased in the face, eye, and nose areas at cooperation, and the gaze factor increased in the right face and nose areas at the low focus. It is expected that this will be used as a basic research to evaluate emotions needed in business environment in virtual space.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.387-388
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• 2003

습식 배연탈황 공정에서는 흡수탑 내에서의 황산화물 흡수율을 높일 목적으로 흡수탑으로 유입되는 배기가스를 약 5$0^{\circ}C$까지 냉각하고, 처리된 배기가스는 연돌에서의 자연 통풍력을 확보하고 연돌 배출 후 수분의 응축으로 인한 백연(white Plume)의 문제를 방지하고자 통상 9$0^{\circ}C$ 이상으로 가온하는 것이 일반적이며 이를 위해 다양한 형식의 열교환기가 설치 운영되고 있다. 탈황공정에서 흔히 GGH(gas to gas heater)라 불리는 Ljungstrom 방식의 열 교환기는 미처리된 고온가스와 처리된 저온 가스가 회전하는 열교환소자로 이루어진 영역을 지나면서 열 교환이 이루어지는 형태로 회전 부위 및 두 가스흐름의 구분 판(sector plate) 등에서 필연적으로 처리가스 흐름 중으로 미처리 가스의 누입이 일어나게 된다. (중략)

• Journal of the Korean Society for Precision Engineering
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• v.29 no.11
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• pp.1178-1182
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• 2012

The organic linings at flue gas desulfurization systems (FGD system) in power plant have the excellent chemical properties but, lose the anticorrosive properties according to the aging with environment conditions. The properties of the organic linings depend on the manufacturing company. Therefore, the basic properties of organic linings for the preestimate of life time should be examined by conducting the aging and the bond strength test according to temperature. The pre-aging samples were compared with the post-aging samples. The temperature conditions of the aging process were 70, 150 and $200^{\circ}C$. The bond strength was calculated and the cross sections of fracture surface were examined by optical microscope and SEM. The $T_g$ was examined by DSC, DTA and TGA.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.133-143
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• 2020

The purpose of this study is to investigate the economic potential of the regions from the mining sector of North Morowali, Central-Sulawesi, Indonesia, and the formulation of pro-business regional development management that aims to create synergy between the local government and mining sector entrepreneurs. This study uses a descriptive qualitative approach by taking data in the form of primary data from FGD and secondary data observations from statistical bureau data in the North Morowali, Indonesia. The analysis unit uses SWOT analysis to determine the economic potential of the North Morowali and Location Quotient (LQ) to analyze the economic potential of the mining sector. The research period covers one year (2018-2019) in North Morowali, Indonesia. All the mining products have considerable potential as a financing unit in North Morowali, while mining potential has not been maximally exploited. The absence of regulations, facilities such as road access, and optimal land and sea transportation are the causes of the difficulty of optimization and access to explore mining products comprehensively. As a new province at Central Sulawesi, more efforts and the role of government are needed to focus attention to North Morowali as an area with great potential in the mining sector.

• Asian Journal of Business Environment
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• v.10 no.2
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• pp.33-41
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• 2020

Purpose: This study assesses the marketing practices and value-added fish products under the Coral Reef Rehabilitation and Management Program (COREMAP) in East Indonesia. Research design, data and methodology: This study gathered qualitative and quantitative data through i) focus group discussions (FGD) with fishers, traders and COREMAP officers, ii) surveys and iii) interviews with fishermen and traders. This study surveyed 714 households (365 in COREMAP and 349 in non-COREMAP) and 33 traders (17 in COREMAP and 16 in non-COREMAP) using structured questionnaires between January and March 2016. This study used Shepherd's Index to estimate the marketing efficiency for each stage of the marketing channel. For value-added fish products, the value is determined by the difference between processed output and the raw product used. Results: Marketing cost in the non-COREMAP area was more efficient than in COREMAP as indicated by lower operational cost and higher selling price. However, no value-added fish products were produced in the non-COREMAP area. This study noted a lower catch in COREMAP area, which implies COREMAP program successfully reduced fishing pressure. Conclusions: This study identified poor infrastructure and the limited market as the major problems in developing value-added fish products in both COREMAP and non-COREMAP area.

• Journal of Pharmacopuncture
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• v.27 no.2
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• pp.142-153
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• 2024

Objectives: This study aimed to analyze the educational needs of interns and residents in Korean medicine as the first step in developing an education program to improve their research competencies. Methods: A mixed-method design, incorporating both quantitative and qualitative data collection methods, was used to investigate the educational needs for research competencies among interns and residents working in Korean medicine hospitals nationwide. Data were collected through online surveys and online focus group discussions (FGDs), and processed using descriptive statistical analysis and thematic analysis. The study results were derived by integrating survey data and FGD outcomes. Results: In total, 209 interns and residents participated in the survey, and 11 individuals participated in two rounds of FGDs. The majority of participants felt a lack of systematic education in research and academic writing in postgraduate medical education and highlighted the need for nationally accessible education due to significant disparities in the educational environment across hospitals and specialties. The primary barrier to learning research and academic writing identified by learners was the lack of knowledge, leading to time constraints. Improving learners' research competencies, relationship building, autonomy, and motivation through a support system was deemed crucial. The study also identified diverse learner types and preferred educational topics, indicating a demand for learner-centered education and coaching. Conclusion: This study provides foundational data for designing and developing a program on education on research competencies for interns and residents in Korean medicine and suggests the need for initiatives to strengthen these competencies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.1-6
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• 2021

Mercury, once released, is not destroyed but accumulates and circulates in the natural environment, causing serious harm to ecosystems and human health. In the United States, sulfur-impregnated activated carbon is being considered for the removal of vapor mercury from the flue gas of coal-fired power plants, which accounts for about 32 % of the anthropogenic emissions of mercury. In this study, a high-efficiency porous mercury adsorption material was developed to reduce the mercury vapor in the exhaust gas of coal combustion facilities, and the mercury adsorption characteristics of the material were investigated. As a result of the investigation of the vapor mercury adsorption capacity at 30℃, the silica nanotube MCM-41 was only about 35 % compared to the activated carbon Darco FGD commercially used for mercury adsorption, but it increased to 133 % when impregnated with 1.5 % sulfur. In addition, the furnace fly ash recovered from the waste copper regeneration process showed an efficiency of 523 %. Furthermore, the adsorption capacity was investigated at temperatures of 30 ℃, 80 ℃, and 120 ℃, and the best adsorption performance was found to be 80 ℃. MCM-41 is a silica nanotube that can be reused many times due to its rigid structure and has additional advantages, including no possibility of fire due to the formation of hot spots, which is a concern when using activated carbon.