• Journal of the Korean Institute of Gas
• /
• v.2 no.3
• /
• pp.60-69
• /
• 1998

Methane, the major constituent of natural gas, had been converted to higher hydrocarbons by microwave and radio-frequency plasma in vacuum condition. Methane had been activated to plasma by suppling high energy then converted to ethane, ethylene, acetylene. The direct conversion process of methane had produced few by-products and demanded low-energy. The plasma sources were microwave and radio-frequency. Two types of reactor had been used to activate methane. One is common single tubular-type reactor and the other is series coil-type reactor which used for the first time in this study. To produce more C2 products, methane had been converted by a plasma and catalyst. The results of this study could be used to study mechanism of plasma reaction of methane, design the plant-scale reactor.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.985-986
• /
• 2012

• Journal of the Korean Data and Information Science Society
• /
• v.27 no.6
• /
• pp.1593-1600
• /
• 2016

This paper suggests a temperature guidance for requirements which must be addressed in the preparation of specifications for military equipment used in land applications in the Korean peninsula. In general, the equipment should be designed to operate during all but a certain small percentage of the time. Daegu and Yangpyeong are the hottest and coldest regions by month, respectively, based on surface weather observations over 132 regions from 1904 to 2014. The 1-percent high and low temperatures for land environment in the South Korea are $38.7^{\circ}C$, and -$29.0^{\circ}C$, respectively. This paper also presents the temperature values occurring for specified frequencies of occurrence during the most severe month. Diurnal cycles associated with the hottest and coldest top one-percent temperatures, including associated solar radiation, relative humidity, and wind-speed are provided.

• Journal of the Korea Society for Simulation
• /
• v.15 no.4
• /
• pp.143-151
• /
• 2006

This paper deals with the simulation model for design and operations of A-Mart logistic center for low temperature products. In developed simulation model, receiving docks, digital classification system (DCS), shipping docks, material handling devices and manual sorting stations are considered. Five types of cargo such as fruits, palletized fruits, delicatessen and fisheries, vegetables and refrigerated cargoes are considered. The simulation model and process animation are developed using the simulation package ARENA. Among various design and operation alternatives consisting of the number of workers of receiving dock, allocation of receiving docks by cargo types, DCS capacity, the number of folk-lift, the number of manual sorting operators and overall layout, the best alternatives of each subsystem are selected by simulation analysis. The major performance measures such as DCS throughput, utilization of operators at each station, receiving docks utilization and folk-lift utilization are considered for the alternative evaluation.

• Analytical Science and Technology
• /
• v.14 no.3
• /
• pp.274-285
• /
• 2001

In this study, the thermal desorption-cryofocusing-gas chromatographic(TD-C-GC) method was developed for determination of volatile organic compounds(VOCs) in ambient air and was applied at the municipal solid waste landfill sites. On-column cryofocusing was possible only with a 100 ml dewars bottle in TD-C-GC method with a stainless steel column. However, high operating pressure was needed for purging VOCs from the absorbent trap, which was able to solve by pressure programming with a electric pressure controller. By using both pressure and temperature programming brought increasing of resolution power in on-column cryofocusing method, but the high pressure caused a leakage of sample tube with repeated use. A loop cryofocusing devise was also developed and compared with the direct on-column method. In loop cryofocusing method, VOCs were concentrated on a 0.8mm i.d. loop which is located between the injector and separation column by using liquid nitrogen. In order to purge VOCs from the absorbent trap, only 0.4 psi of pressure was need in the loop cryofocusing method. Dual detection system was applied for the analysis of VOCs; a FID was used for hydrocarbons and a FPD was used for sulfur-containing compounds. Qualitative analysis was done by on-column cryofocusing GC-MS system. Among the large number of VOCs, toluene was the most abundant. Hydrogen sulfide, dimethyl sulfide, carbon disulfide, dimethyl disulfide and methyl propyl disulfide were detected at landfill site by FPD.

• 전기의세계
• /
• v.26 no.2
• /
• pp.14-18
• /
• 1977

송전선의 굵기에 따라, 지지물의 높이를 결정하기 위하여 종단도를 그릴때마다 이도설계를 하여야 한다. 같은 전선이라도 온도에 따라, ruling span에 따라, 풍압 및 피빙의 부착여하에 따라 장력이 다르게 된다. 철탑설계시에 고온계, 저온계의 최대장력을 계산하여야 한다. 가선시에는 온도별 span별로 이도표를 만드러야 한다. 특히 복도체가선시에는 이도표를 만들어 가선하여야 된다. 이러한 계산은 computer에 의하면 많은 시간을 절약할 수 있으며 정확한 게산을 할 수 있다. 본고는 이러한 목적에 맞는 computer program에 대하여 설명하고저 한다.

• International Journal of Highway Engineering
• /
• v.6 no.4 s.22
• /
• pp.1-12
• /
• 2004

This study evaluated the asphalt binder characteristics for the hot-recycled asphalt mixture in which RAP was added in ambient temperature for surface course as well as for base course. RAPs were collected from four sources and their physical properties were evaluated. Mix designs were performed using 10 and 20% RAP contents for surface courses and 10, 20 and 30% for base courses. A virgin asphalt with the penetration grade of 60-80 was used for mixing recycled mixtures. Physical properties of recycled binders, including penetration, absolute viscosity, GPC, BBR and penetration after TFO were measured. From the results, regression analysis of absolute viscosity versus LMS in GPC showed $R^2$ being over 0.95, showing that GPC results estimate the absolute viscosity with relative accuracy. In BBR test, the resistance of recycled mixtures at low service temperature was inferior to the control, because the low temperature PG of recycled binder was one grade higher than that of the control binder.

• Progress in Superconductivity and Cryogenics
• /
• v.10 no.1
• /
• pp.37-41
• /
• 2008

Superconducting Electrodynamic suspension(EDS) system is generated by the interaction between the magnetic field made by the induced the eddy current in the ground conductor and the moving magnetic field made by onboard superconducting magnet. The levitation force of EDS system, which is proportional to the strength of the moving magnetic field, becomes saturated according to the increase of the velocity. Especially, the levitation force is influenced by the structure of HTS magnet and ground magnet. This paper deals with the optimal design condition for the HTS levitation magnet. The 3-D numerical analysis with FEM was used to find the distribution of the magnetic field, the optimal coil structure, and the calculation of the levitation force.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.1 no.1
• /
• pp.79-84
• /
• 2008

Proposed EEFL inverter design method with Dimming control to use microprocessor. Reduce power loss using Energy Recovery method, and design inverter control program that use RS-232 communication. Also, low temperature driving time shortened 50% that use duty variable control.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.11a
• /
• pp.471-472
• /
• 2003

국민의 보건의식이 높아짐에 따라서, 병원에서 배출되는 감염성 폐기물의 안정적 처리에 대한 요구가 높아지고 있다. 감염성 폐기물 처리방법으로는 가압멸균과 산화소각 및 건류소각이 있는데, 본 연구 목적은 100％멸균이 보장되는 중형 산화소각을 설계하고 이의 운영특성을 파악하는데 있다. 감염성 폐기물은 일정규격의 상자에 담아서 배출되며, 저온에서 이송과 저장이 이루어지며, 소각로 투입시에도 상자를 파손하지 않고 투입되어야 하는 등의 엄격한 규정에 따라서 소각하여야 한다. 본 연구는 이러한 감염성 폐기물처리 법규 및 감염성 폐기물의 연소 특성을 파악하여 소각로 설계의 기본자료로 활용하였다. (중략)