• Journal of the Korean Chemical Society
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• 제10권1호
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• pp.1-3
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• 1966

The organic yields (i.e. fraction of nuclear events resulting in organic compound formation) of the radioative neutron capture reactions of halogens in purified bromobenzene have been determined varying extraction time, at $100^{\circ}C$ for thermal effect, varying irradiation time, varying neutron flux and with additional U. V. irradiation. Among the important results are; (1) The organic yields show no remarkable fluctuations with time following neutron irradiation; (2) The organic yields show no change with thermal energy; (3) The organic yields of degassed samples are same in different length of irradiation time whereas the yields of the samples in open air appear to increase with increasing time of irradiation (4) The organic yields increase remarkably with increased neutron flux; (5) The organic yields show a sharp increase by additional U. V. irradiation after neutron irradiation.

• Proceedings of the KIEE Conference
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2678-2680
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• 2000

In this paper, we calculates mathematical model of ex-core neutron flux monitoring system for nuclear reactor and design the digital system using the bilinear transformations. The output pulse shape and resolving time of the system determines from the proposed method.

• Membrane Journal
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• 제6권1호
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• pp.10-21
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• 1996

This study is undertaken to investigate the major factor which causes a fouling phenomenon in membrane separation system and effect of hydrophilic treatment on fouling repression of hydrophobic polymer (polysulfone, PSf). Chlorosulfonic acid (CSA) and sulfuric acid as a sulfonating agents are used to produce sulfonated PSf (SPSf). SPSf membrane is prepared under several conditions to investigate it's separation process. The extent of fouling-repression is measured by membrane filtration index (MFI) value. With increasing the ion exchange capacity (I.E.C), the flux of SPSf membrane is decreased but the rejection is increased and the flux is less reduced. According to the MFI value, the SPSf membrane has a fouling-retardant effect.

• KIEAE Journal
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• 제2권3호
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• pp.33-38
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• 2002

The intermediate range of temperatures($100{\sim}300^{\circ}C$) which can be achieved with CPCs(Compound Parabolic Concentrators) without tracking device provides both economic and thermal advantages for solar collector design. The present paper summarizes critical design considerations for CPC with cylindrical absorber and its optical performance using ray tracing program. Concentration ratios vary as acceptance half angle, ratio of reflector height to aperture width and ratio of reflector area to aperture area. This effects showed that the concentration ratio was increased as acceptance angle but optimum ratio of reflector height to aperture width existed at critical value. As a result of ray tracing, solar ray losses was maximized at acceptance half angle and this problem was solved by increasing absorber tube diameter. The concentrating flux distribution on the absorber surface was uniform but peak flux existed.

• Proceedings of the KIEE Conference
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• 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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• pp.136-138
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• 2009

A new class of electronically commutated brushless motor, the flux-switching motor(FSM) is gradually emerging in power tools and household appliances especially fan application. This motor offers advantages of both high-power density and relatively high efficiency This paper presents the principle of the FSM and design of the 12/6 pole FSM drive system. Finally, test results of the prototype motor are provided to verify a validity of the fan application.

• Proceedings of the KIEE Conference
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.150-152
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• 2005

On this study is PM excited transverse flux linear motor for compressor on an air condenser. The present day, it is general use for linear motor on compressor, so this paper conducted efficiency to compare with varing mover and stator's shape.

• Proceedings of the KIEE Conference
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.27-29
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• 2001

In this paper, we study in magnetizing the NdFeB magnet which is inserted in a squirrel cage rotor. The inserted NdFeB magnet need much more magnetizing flux than that of ferrite magnet. Also the eddy current flowing in rotor bar disturbs the magnetizer in magnetizing the NdFeB magnet. The existing magnetizing yoke is designed by increasing the coil turn. But we recognize that only by increasing the coil turn it is impossible to make NdFeB magnet magnetized fully. Hence, in this paper we propose the method of increasing magnetizing flux by reducing the rotor bar area.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.101-104
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• 2004

We have fabricated a channel of superconducting flux flow transistor(SFFT) using the voltage-biased atomic force microscope(AFM) TiO tip and performed numerical simulations for the SFFT controlled by the magnetic field with a control current. The critical current density in a channel of the fabricated SFFT was decreased with the applied current by a control line. By comparing the measured with theoretical results, we showed a possibility of fabrication of an SFFT with a nano-channel using AFM anodization process technique.

• Nuclear Engineering and Technology
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• 제49권6호
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• pp.1143-1156
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• 2017

This paper describes recent development activities of the GENESIS code, which is a transport code for heterogeneous three-dimensional geometry, focusing on applications to reactor core analysis. For the treatment of anisotropic scattering, the concept of the simplified Pn method is introduced in order to reduce storage of flux moments. The accuracy of the present method is verified through a benchmark problem. Next, the iteration stability of the GENESIS code for the highly voided condition, which would appear in a severe accident (e.g., design extension) conditions, is discussed. The efficiencies of the coarse mesh finite difference and generalized coarse mesh rebalance acceleration methods are verified with various stabilization techniques. Use of the effective diffusion coefficient and the artificial grid diffusion coefficients are found to be effective to stabilize the acceleration calculation in highly voided conditions.

• Journal of Advanced Marine Engineering and Technology
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• 제7권1호
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• pp.64-78
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• 1983

In nucleate boiling, bubbles are created by the expansion of entrapped gas or vapor at small cavities in the surface of heat transfer. Namely, surface roughness is the important factor of heat transfer. This paper deals with the characteristics of boiling curve according to surface roughness. Freon-113 is used as the experimental fluid. The results are as follows; 1. In the case of the same as "q=C$\Delta$T$^{n}$ ", the lower numberical index "n", the larger heat transfer coefficient and the lower wall superheat "$\Delta$T" is obtained for the rougher surface. 2. In the working of every kind of heat transfer sruface with boiling, improvement of capabilities of heat transfer can be devised by adding suitable roughness on the heat transfer surface. 3. When the metal nets of moderate mesh number are established, the capabilities of heat transfer can be improved in evaporation of liquid in vessels. But in the case that the sucession of bubbles in checked by using the nets which are too tight, the generation of bubbles union decreases critical heat flux. decreases critical heat flux.