• Title/Summary/Keyword: Stabilizer

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An Experimental Study on the Characteristics of Gas Burner Nozzle (가스버너의 노즐특성에 관한 실험적 연구)

  • Chung, D.H.;Kim, W.B.;Dong, S.K.
    • 한국연소학회:학술대회논문집
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    • 1995.06a
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    • pp.105-121
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    • 1995
  • The objective of this study is to find out the design data for gas burner with an axal and radial type nozzles. The design parameters are chosen as the stabilizer type, the jet hole size of gas nozzle, the distance between gas nozzle and stabilizer, the size of stabilizer and the hole size of stabilizer, the stabilizer type with or without air swirler, the angle of swirler. For the experimental test combustor sizing ${\phi}1.3m{\times}L4.5m$ is designed and manufactured, in which the set up of power diagram, the exhaust gas analysis, blow-off test, the flame temperature and the direct photography are performed.

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Dispersion Polymerization of Styrene Employing Lyophilic Comonomer in the Absence of Stabilizer: Synthesis of Impurity-free Microspheres

  • Han, Hye-Kyung;Lee, Jeong-Woo;Hong, Jin-Ho;Shim, Sang-Eun
    • Macromolecular Research
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    • v.17 no.7
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    • pp.469-475
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    • 2009
  • We investigated the feasibility of dispersion polymerization without any stabilizer, which has been considered essential for ensuring colloidal stability. By employing small amounts of a lyophilic comonomer, 4-vinyl pyridine, styrene was successfully polymerized by dispersion polymerization in aqueous alcohol without stabilizer to afford stable poly(styrene-co-4-vinyl pyridine) copolymer microspheres. The stable microspheres were produced in the 4-vinyl pyridine range of 2-15 wt% to styrene. Without 4-vinyl pyridine, severely coagulated particles were obtained, implying that the poly(4-vinyl pyridine) moiety endowed colloidal stability. The polymerization kinetics, behavior, and properties of the ultimate particles showed general features of dispersion polymerization. The study results suggest that stabilizer- tree dispersion polymerization is possible, thereby facilitating the synthesis of impurity(stabilizer)-tree polymer particles.

Application of Soil Stabilization Technique for Shoulder Construction in Sri Lanka (스리랑카 길어깨 적용을 위한 안정처리 재료의 적용성 평가 연구)

  • Park, Ki Soo;Park, Hee Mun
    • International Journal of Highway Engineering
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    • v.20 no.4
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    • pp.21-26
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    • 2018
  • PURPOSES : The objective of this study is to evaluate the application of soil stabilization method for soft shoulder construction in the iRoad Project of Sri Lanka. METHODS : Firstly, the quantitative analysis of soil strength improvement due to soil stabilization was done for soil samples collected from iRoad construction sites. Two types of soils were selected from iRoad Project sites and prepared for soil stabilization testing by the Road Development Authority. Secondly, the appropriate stabilizer was selected at given soil type based on test results. Two different stabilizers, ST-1 and ST-2, produced in Korea were used for estimating soil strength improvements. Finally, the optimum stabilizer content was determined for improving shoulder performance. The uniaxial compressive strength (UCS) test was conducted to evaluate the strength of stabilized soil samples in accordance with ASTM D 1633. The use of bottom ash as a stabilizer produced from power plant in Sri Lanka was also reviewed in this task. RESULTS : It is found from the UCS testing that a 3% use of soil stabilizer can improve the strength up to 2~5 times in stabilized soft shoulder soils with respect to unstabilized soils. It is also observed from UCS testing that the ST-1 shows high strength improvement in 3% of stabilizer content but the strength improvement rate with increase of stabilizer content is relatively low compared with ST-2. The ST-2 shows a low UCS value at 3% of content but the UCS values increase significantly with increase of stabilizer content. When using the ST-2 as stabilizing agent, the 5% is recommended as minimum content based on UCS testing results. Based on the testing results for bottom ash replacement, the stabilized sample with bottom ash shows the low strength value. CONCLUSIONS : This paper is intended to check the feasibility for use the soil stabilization technique for shoulder construction in Sri Lanka. The use of soil stabilizer enables to improve the durability and strength in soft shoulder materials. When applying the bottom ash as a soil stabilizer, various testings should be conducted to satisfy the specification criteria.

Study on the Aerodynamic Performance of a Cross-Flow Fan for the Various Design Factors of an Indoor Room Air-Conditioner (룸에어콘 실내기의 설계인자 변화에 따른 관류홴의 공력성능 연구)

  • Kim, J.K.;Jeong, K.J.
    • Journal of Power System Engineering
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    • v.9 no.3
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    • pp.33-38
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    • 2005
  • The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The purpose of this paper is to investigate the effects of a rear-guider and a stabilizer on the aerodynamic performance of a cross-flow fan. The design factors considered in this paper are a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle, respectively. This experiment was carried out with a constant revolution number of 700 rpm in a cross-flow fan installed in the fan tester. The static pressure, flowrate, torque, and revolution number were measured in this paper. Also, the pressure coefficient and the efficiency were analysed according to the various assembly conditions using a stabilizer setup angle, a stabilizer clearance, and a rear-guider clearance in the indoor room air-conditioner.

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Quench/recovery test results of the YBCO coated conductors(CCs) having various stabilizer thicknesses (YBCO coated conductors(CCs)의 안정화재 두께 변화에 따른 quench/recovery 특성 분석에 관한 연구)

  • Kwon, N.Y.;Kim, H.S.;Kim, K.L.;Kim, K.J.;Yim, S.W.;Kim, H.R.;Hyun, O.B.;Lee, H.G.
    • Progress in Superconductivity and Cryogenics
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    • v.11 no.3
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    • pp.10-14
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    • 2009
  • Since a stabilizer of YBCO coated conductor (CC) plays a very important role of bypassing over-current and transferring heat generated in the moment of fault, it is one of big issues to determine the material of the stabilizer and its dimension for the high performance of the HTS power application system. Especially, in the case of a superconducting fault current limiter (SFCL), which requires it to react immediately to the occurrence of fault, characteristics of stabilizer are decisive in limiting fault current and recovering superconducting properties during and after quenching. In this paper, the quench / recovery characteristics of YBCO CCs with various thickness of stabilizer were analyzed. The quench/recovery test carried out at 20 $V_{rms}$, 5 cycles (60 Hz) and results showed that as the thickness of the stabilizer decreased, both the final approach temperature and the recovery time decreased.

Design of the RLG Current Stabilizer for Attitude Control in the Satellite (저궤도 위성 자세제어용 RLG 전류 안정화 회로 설계)

  • Kim, Eui-Chan;Lee, Heung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.1
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    • pp.98-101
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    • 2008
  • In this paper, we describe the RLG current stabilizer circuit for attitude control in the satellite. The RLG makes use of the Sagnac effect within a resonant of a HeNe laser. The difference between two discharge currents causes one of the gyro bias errors. The theoretical background and current stabilizer are introduced. It is verified that the circuit designed is applicable to the test of input voltage and temperature.

Time Division Proportional-Integral Power System Stabilizer Using The Gradiant Method (기울기 방법을 이용한 시분할 PI 전력계통 안정화 장치)

  • Jung, Hae-Won;Baek, Young-Sik
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.900-902
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    • 1997
  • Stabilization of Power systems is investigated using a proportional-integral power system stabilizer(PI PSS). Time division PI PSS is examined in this paper. Two approaches are presented for determining the optimal stabilizer gains of the proposed PI PSS. Simulation results show that the proposed PI PSS yields better system dynamic performance and stability than the sub-optimal stabilizer in the sense of having greater damping in response to a step disturbance.

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Design of Multimachine Power System Stabilizer using CLF-based SM-MF Controller : Part 3 (폐-루우프 피이드백에 기준한 SM-MF 제어기를 이용한 다기 전력계통안정기 설계 : Part3)

  • Lee, Sang-Seung;Park, Jong-Keun
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.1168-1170
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    • 1997
  • In this paper, the sliding mode-model following(SM-MF) power system stabilizer(PSS) including closed-loop feedback(CLF) for single machine system is extended to multimachine system. Simulation results show that the SM-MF multimachine stabilizer is able to achieve asymptotic tracking error between the reference model state and the controlled plant state at different initial conditions.

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A digital signal processor with a stabilizer for open-loop fiber optic gyroscope (개회로 광섬유 자이로스코프용 신호처리기의 안정화)

  • Kim, Do-Ik;Yang, Gwang-Jin;Ye, Yun-Hae
    • Proceedings of the Optical Society of Korea Conference
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    • 2004.02a
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    • pp.296-297
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    • 2004
  • A Signal processor for the open-loop fiber optic gyroscope(FOG) is equipped with a stabilizer to reduce the error due to drift of fiber phase modulator (FPM). The stabilizer is designed to be operated to maintain the ratio of amplitude and phase between harmonics in the FOG signal. When FPM stabilizer is used, the temperature drift of FOG is reduced to less than 0.5 deg/hr in change of 20$^{\circ}C$.

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