• Proceedings of the KIEE Conference
• /
• 2002.11a
• /
• pp.209-211
• /
• 2002

A simple-structured thermal plasma generator for waste gas treatment has been studied. The thermal plasma technology applied to waste treatment has undoubtedly gained high importance owing to its outstanding properties such as flexibility, compact reactor, and clean treatment. Moreover, the thermal plasma generated by ac power has some additional advantages such as simple electrode system and easy maintenance. A prototype 200kW class plasma generator with specifications of 10-30m/sec gas velocity and 3000-5000K temperature on the center just outside of the nozzle has been designed and tested. Case studies on heat transfer, heat flow, velocity distribution, and temperature distribution using a commercial simulation package show lots of flexibility in design. The experimental results from theprototype generator show that the ac thermal plasma is easily controlled by working gas flow once it is ignited. A stabilization condition is discussed with the data from monitoring arc voltage drops with respect to gas flow rate during the test.

• Journal of Korean Society on Water Environment
• /
• v.21 no.3
• /
• pp.219-229
• /
• 2005

The analytical methods for dioxins in water sample from wastewater to tap water were reviewed. For extraction method, liquid-liquid extraction (LLE) has been widely used, however, this process needs too much time and man power. New approach including solid phase extraction (SPE) is now applicable to large volume of water sample with high extraction efficiency. Column clean up in classical analytical methods were very complex and time consuming procedures during decade. Modifications were tried to decrease solvent and reagents volume. Moreover, use of column connection method has been demonstrated in the environmental matrices. Instrumental configurations also have been improved, in which GC/MS/MS with large volume injection approach can analyze picogram levels. Absolute sensitivities of HRMS increased compared to old versions of double focusing sector type mass spectrometers. Based on these analytical evolutions during last 10 years, we tried to optimize the analytical method for dioxins in water sample from sample extraction to instrumental analysis.

• Journal of Radiation Industry
• /
• v.9 no.3
• /
• pp.127-130
• /
• 2015

Since the accident at the Fukushima Daiichi power plant, Prussian blue (PB) has attracted increasing attention as a material for use in decontaminating the environment. We have focused the fundamental mechanism of specific $Cs^+$ adsorption into PB in order to develop high-performance PB-based $Cs^+$ adsorbents. The ability of PB to adsorb Cs varies considerably according to its origin such as what synthesis method was used, and under what conditions the PB was prepared. It has been commonly accepted that the exclusive abilities of PB to adsorb hydrated $Cs^+$ ions are caused by regular lattice spaces surrounded by cyanido-bridged metals. $Cs^+$ ions are trapped by simple physical adsorption in the regular lattice spaces of PB. $Cs^+$ ions are exclusively trapped by chemical adsorption via the hydrophilic lattice defect sites with proton-exchange from the coordination water. Prussian blue are believed to hold great promise for the clean-up of $^{137}Cs$ contaminated water around nuclear facilities and/or after nuclear accidents.

• Journal of the Korean Solar Energy Society
• /
• v.31 no.2
• /
• pp.72-81
• /
• 2011

The wind data obtained from an AWS(Automated Weather Station) was used to predict the AEP(annual energy production) of Gangwon wind farm having a total capacity of 98 MWin Korea. A wind energy prediction program based on the Reynolds averaged Navier-Stokes equation was used. Predictions were made for three consecutive years starting from 2007 and the results were compared with the actual AEPs presented in the CDM (Clean Development Mechanism) monitoring report of the wind farm. The results from the prediction program were close to the actual AEPs and the errors were within 7.8%.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.596-601
• /
• 2006

Because of insufficiency of energy resources and pollution of environment, it is necessary to develop alternative energy sources. Nuclear fission energy is used widely for source of electric Power but being restricted due to radioactivity problem. Nuclear fission is highlighted as the new generation of nuclear energy and researched worldwide because of low risk of radiation effect. The representatives of fusion research is China's EAST, KSTAR of Korea and ITER of world. Korea Superconducting Tokamak Advanced Research(KSTAR) project is on progress for the completion in August, 2007. In this study, the research of utility system for KSTAR be carried out. The utility system of KSTAR is consist of water cooling & heating system, $N_2$ gas system, DI water system, service water system and instrument air & auto control system. The progress of KSTAR utility system is under commissioning state after construction completion. The optimal operation scenario will be verified during commissioning and adopted to the KSTAR operation.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.19 no.3
• /
• pp.387-419
• /
• 2021

The challenges facing companies and institutions surrounding civil nuclear decommissioning are diverse and many, none more so than those faced in the United Kingdom. The UK's Generation I nuclear power plants and early research facilities have left a 'Nuclear Legacy' which is in urgent need of management and clean-up. Sellafield is quite possibly the most ill-famed nuclear site in the UK. This complex and challenging site houses much of what is left from the early days of nuclear research in the UK, including early nuclear reactors (Windscale Piles, Calder Hall, and the Windscale Advanced Gas Cooled Reactor) and the UK's early nuclear weapons programme. Such a legacy now requires careful management and planning to safely deal with it. This task falls on the shoulders of the Nuclear Decommissioning Authority (NDA). Through a mix of prompt and delayed decommissioning strategies, key developments in R&D, and the implementation of site licenced companies to enact decommissioning activities, the NDA aims to safety, and in a timely manner, deal with the UK's nuclear legacy. Such approaches have the potential to influence and shape other such approaches to nuclear decommissioning activities globally, including in Korea.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.6
• /
• pp.71-76
• /
• 2020

Recently, the market of private study room continues to grow due to increased usage of private study room. However, old study room operators often have problems with cleanliness and theft, and cannot handle them in real time. Also, there is a problem of wasting power since users usually leave their desk for a long time with the lights on. Thus, in this paper, we intended to design a service which can prevent theft, clean up the user's desk, and adjust lighting system according to the user's condition based on Arduino system. Also, we tried to design a system which sends notifications from information of android-based IoT(Internet of Things), to the terminal when other people approach to the user's desk or try to steal user's item.

• Journal of Hydrogen and New Energy
• /
• v.31 no.6
• /
• pp.530-545
• /
• 2020

This paper reviews and summarizes the fuel-cell-related studies those have been recently published in major Korean Citation Index journals, aiming at analyzing the research trend in fuel cell technologies. Six major journals are selected for the literature survey; 57 papers are chosen for the detailed analysis through a screening examination on the total 1,040 papers published during between 2018 and 2020. Papers are classified into six technical categories, such as i) electrode, ii) electrolyte, iii) bipolar plate and stack, iv) fuel cell system, v) balance of plant, and vi) diagnosis-related studies, and summarized by the experts in the relevant area. Through this paper, we provide a comprehensive review on the recent trends and progress in fuel-cell-related research work in Korea.

• Journal of Appropriate Technology
• /
• v.7 no.2
• /
• pp.151-161
• /
• 2021

The application of appropriate technologies in a developing country is an opportunity to introduce green technology which may lead people to imagine a better life. This point is at the intersection of appropriate technology and sustainable development. This research focuses on Hatphain village where there is no clean water, sewage system, or power lines. Two environmental technologies (an unpowered water purification system, Ongdalsaem and an eco-toilet system, BeeVi toilet) were introduced, based on the concepts of the environmental self- sustainable village and feces Standard Money (fSM). We found that the Ongdalsaem was effective in reducing the concentration of nitrogen and lead in the water in Hatphain. The BeeVi water-free toilet was installed, allowing urine and feces to be separated and used as compost. We strived to spread ideas of sustainability using new eco-circulation experiences and encouraging learning about environmental technology through practical and playing facilities that residents managed themselves.

• Journal of the Korean Society of Safety
• /
• v.37 no.6
• /
• pp.18-24
• /
• 2022

Hydrogen is a clean fuel and is used in many applications in power systems such as fuel cells. It has unique properties such as wide flammability, high burning velocity, and difficulty to liquefy, which lead to critical safety issues. Fire and explosion are the most frequently occurring accidents and one of the major reasons is autoignition. In the ignition process, the chemistry of hydrogen combustion depends mainly on radical pools, and the temperature at which chain-branching and terminating rates are equal is called the crossover temperature. This study addresses the homogeneous autoignition of diluted hydrogen-air mixtures to investigate the effects of dilution on the crossover temperature to prevent explosions in the future. The new criterion for crossover temperature is introduced by only hydrogen radicals to adjust more simply. The detailed calculations indicate that the crossover temperatures are low at high dilutions of carbon dioxide and nitrogen because the concentrations of active radicals are reduced when an inert gas is added. This result is expected to contribute to hydrogen safety and realize a hydrogen society in the future.