• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.575-580
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• 2020

In this study, we simulated an amine regeneration process with heat-stable salts removal unit. We derived the optimal operating conditions considering the flow rate of waste, the removal rate of heat-stable salts, and the loss rate of MDEA (methyl diethanolamine). In the amine regeneration process that absorbs and removes acid gas, heat-stable salt impairs the absorption efficiency of process equipment and amine solution. An ion exchange resin method is to remove heat-stable salts through neutralization by using a strong base solution such as NaOH. The acid gas removal process was established using the Radfrac model, and the equilibrium constant of the reaction was calculated using Gibbs free energy. The removed amine solution is separated and flows to the heat-stable salts remover which is modeled by using the Rstoic model with neutralization reaction. Actual operation data and simulation results were compared and verified, and also a case study was conducted by adjusting the inflow mass of removal unit followed by suggesting optimal conditions.

• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.30-36
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• 1975

The extraction efficiency of orange-yellow pigment from the Gardenia was greatly depended upon the extraction time, extraction temperature, volume of solvent used and fat contents of the Gardenia. From the experimental results, the amounts of extracted pigment (P) was proportional to the $log\;t^{\;1{\cdot}15}$ of extraction time$(t;\;0{\sim}60\;min.)$, the $log\;T^{3{\cdot}73}$ of extraction temperature$(T;\;5{\sim}60^{\circ}C)$, the $log\;S^{3{\cdot}7}$ of volume of solvent$(S;\;5{\sim}50\;ml)$, and the -4X of fat contexts of sample $(X;\;0{\sim}0.\;15)$ at $18^{\circ}C$ for 10 minutes. Finally, the modified empirical equation was derived as follow; $P{\simeq}1.15\;log\;t+3.73\;log\;T+3.7\;log\;S-4X-6.4$ In addition to that, the most optimum conditions of pigment extraction were determined as 30 minutes of operation time, $40^{\circ}C$ of temperature. Deffated Gardenia was more productive than natural Gardenia in the pigment extraction.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.368-377
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• 2012

The comprehensive countermeasures against school violence recently announced by the government include some content on physical education classes. Physical education has long been ignored in school paradoxically in spite of the deteriorating physical strength and health of adolescents. The physical education subject undervalued in the middle of overly excessive competitions for college entrance exams finds its core goal in whole person education and officially emphasizes the development of personality aspects, which means that physical education claims important significance by providing diverse approaches to school violence prevention. This study thus set out to enhance the roles of physical education for school violence prevention. In Korean society, school violence has taken deep root due to the combined results of individual, family, school and community factors, the growth-first policy driven by compressed modern growth, and neoliberalism based on economic efficiency. School violence possesses such fixed value systems and convictions in Korean society. Education has failed to achieve some effectiveness because of the serious level of school violence, which calls for assessment of ideology having big impacts on educational environments. Given that it has been rediscovered that physical education has legitimacy of alleviating or preventing school violence through its value, an alternative to eradicate school violence should start with physical education normalization in school. Specific alternatives including the activation of sports clubs in school will be established as more fundamental practical alternatives when accompanied by the development of school violence-related programs and the operation of in-service training programs for physical education teachers.

• Convergence Security Journal
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• v.13 no.2
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• pp.33-43
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• 2013

The Private Security Industry of Korea began after served security service for the United States army of 8 division. The industry grew up after establish private security regulation on December 31th of 1976. Early 1980's the industry was accelerated from bringing technical knowledge of developed nations rapidly. Also, private security was gotten into the spotlight by one of futurity industry instead public security after companies performed 86 Asian game and 88 Seoul Olympic successfully. Therefore, the industry became to increase qualitatively and quantitatively. From late 1990's the private security regulations were revised fifteen times and created about education system, bodyguard, and leader of security. 3,836 private companies and 150,030 private guards had operated until 2012. However, some of companies received administrative measure, because of the companies ran immorally. The minor companies are continuously closed down from the leader's inefficient operation. Approval standard of establishment has imperfect law. Solutions of problems are to provide high quality service, to expand company affairs, to attract specific customers through efficiency expert, to change standard of leader of security guards, to establish security education institution through the government and to intensify requirements to establish the company.

• Journal of Radiation Protection and Research
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• v.33 no.1
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• pp.35-40
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• 2008

A distillation tower is one of the important facilities which separates and refines a crude oil stream according to certain boiling points. Its operation efficiency can affect the productivity of a refinery substantially. The objective of this study is to elucidate some operational information on the internal conditions of a distillation tower from a measurement of density profile by using a sealed gamma-ray source and a radiation detector. Gamma radiation counts were measured by a BGO detector positioned diametrically outside the tower-wall, opposite to the gamma source(Co-60) as the detector and the source were lowered concurrently. From the results, structural abnormality of the trays was not found inside the tower. Considering the flow distribution patterns, however, a vapor phase was dominantly formed at the upper part of the tower and a liquid phase at the lower part. From the gamma scanning of the distillation tower, it is anticipated that the gamma absorption technique can be used as an important tool for confirming the structural soundness of trays and investigating flow distribution in refinery facilities.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.155-161
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• 2012

A dynamic biofilter model was suggested to integrate the effect of biofilter-medium adsorption capacity on the removal efficiency of volatile organic compound (VOC) contained in waste air. In particular, the suggested biofilter model is composed of four components such as biofilm, gas phase, sorption volume and adsorption phase and is capable of predicting the unsteady behavior of biofilter-operation. The process-lumping model previously suggested was limited in the application for the treatment of waste air since it was derived under the assumption that the adsorbed amount of VOC equilibrated with biofilter-media would be proportional to the concentration of dissolved VOC in the sorption volume of biofilter-media. Therefore a Freundlich adsorption isotherm was integrated into a robust biofilter process-lumping model applicable to a wide range of VOC concentration. The values of model parameters related to biofilter-medium adsorption were obtained from the dynamic adsorption column experiments in the preceding article and literature survey. Furthermore a separate biofilter experiment was conducted to treat waste air containing ethanol and the experimental result was compared with the model predictions with various values of Thiele modulus (${\phi}$). The obtained value of Thiele modulus (${\phi}$) was close to 0.03.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.791-794
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• 2010

This study presents channel design of a CDI stack to achieve high removal efficiency in a large scale by applying parallel flow structure with a concentrated stream. The flow pattern in the stack was simulated by COMSOL Multiphysics program. To prove the salt removal performance, a unit cell and 20 cell stacks were tested at a flow rate condition of 18 ml/min and 360 ml/min, respectively. The removal efficiencies of the unit cell and the 20 cell stacks were obtained as 70.8 % and 75.6 %, respectively, with 100 mg/L sodium chloride solution. During the operation of cell test, water pressures of unit cell and 20 cell pair stack maintained in the ranges of 1.1 psi and 1.3~1.5 psi, respectively. It was demonstrated that the parallel cell structure with two concentrated streams can be employed in a large scale CDI for salt removal.

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.57-71
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• 2016

The development of ocean industries is an existing and important problem for South Korea, which is mostly surrounded by sea and has a long coastline along three seas. It is necessary for researchers to make efforts to enhance its cost and time competitiveness, because many ocean-based activities have been carried out in harsh physical conditions when compared with land-based ones. One of these efforts to improve efficiency is to operate an Offshore Supply Base (OSB), which is a basic infrastructure required to develop ocean industries effectively. For this reason, the construction and operation of OSBs have become an issue in Korea. The relevant research is limited. Nevertheless, there are a few reports published by Korean research institution. They focus on promoting ocean industries and only mention the necessity of OSB as a promotion tool for the industries. This study on the other hand, addresses various issues on the construction of OSBs in Korea and suggests implications for them. To examine the conditions on the construction of OSBs in Korea, we conduct case studies of Houston and Singapore, the representative regions where a massive OSB has been constructed and operated. In addition, we use Analytic Hierarchy Process (AHP) to evaluate the relative priorities of the services provided by OSBs if constructed in Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.304-311
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• 2014

In this study, to apply hydrogen energy to ship engine and to generate effective hydrogen production, we investigated the effects of high temperature $H_2SO_4$ feed rate and cooling water rate to pump parts with fixed frequency needed to reciprocate motion and a simulation was conducted at each condition. In the fixed frequency and cooling water inlet flow rate of 0.5 Hz and 3.9 kg/s, we changed the high temperature $H_2SO_4$ flow rate to 47.46 kg/s (it is 105 % of 45.2 kg/s), 49.72 kg/s (110 %), and 51.98 kg/s (115 %). Also, at 0.5 Hz and 45.2 kg/s of frequency and high temperature $H_2SO_4$ flow, the thermal hydraulic analysis was performed at the condition of 95 % (3.705 kg/s), 90 % (3.51 kg/s), and 85 % (3.315 kg/s). In overall simulation cases, the physical properties of materials are more influential to the temperature increase in the pump part rather than the changes on the feed rate of high temperature $H_2SO_4$ and cooling water. A continuous operation of pump was also capable even if the excess feed of high temperature $H_2SO_4$ of about 15 % or the less feed of cooling water of about 15 % were performed, respectively. When the increasing feed of high temperature $H_2SO_4$ of up to 5 %, 10 %, and 15 % were compared with base flow (45.2 kg/s), the deviation of time period rose to a certain temperature and ranged from 0 to 4.5 s in the same position (same material). In case of cooling water, the deviation of time period rose to a certain temperature and ranged from 0 to 5.9 s according to the decreasing feed changes of cooling water at 5 %, 10 %, and 15 % compared to a base flow (3.9 kg/s). Finally, the additional researches related to the two different materials (Teflon and STS for Pitch and End-plate), which are concerned about the effects of temperature changes to the parts contacting different materials, are needed, and we have a plan to conduct a follow-up study.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.900-905
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• 2016

The field of power system harmonics has been receiving a great deal of attention recently. This is primarily due to the fact that non-linear (or harmonic-producing) loads comprise an ever-increasing portion of what is handled at a typical industrial plant. The incidence rate of harmonic-related problems is low, but awareness of harmonic issues can still help increase offshore power plant system reliability. On the rare occasion that harmonics become a problem, this is either due to the magnitude of harmonics produced or power system resonance. This harmonic study used an electrical configuration for the offloading scenario of a Floating LNG (FLNG) unit, considering power load. This electrical network configuration is visible in the electrical network load flow study part of the project. This study has been carried out to evaluate the performance of an electric power system, focusing on the harmonic efficiency of an electrically driven motor system to ensure offshore plant safety. In addition, the design part of this study analyzed the electric power system of an FLNG unit to improve the safety of operation and maintenance.