• Title/Summary/Keyword: suspending

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The Dispersion Stability of $\alpha-Fe_2O_3$ Particulate Soil in the Anionic/Nonionic Mixed Surfactant Solution (음/비이온계 혼합계면활성제 용액에서 $\alpha-Fe_2O_3$ 입자의 분산안정성)

  • 정선영;강인숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.6
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    • pp.854-861
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    • 2004
  • To estimate dispersion stability of particles in anionic and nonionic surfactant mixed solution, suspending power was examined as functions of duration time of suspension, ionic and nonionic surfactant mixed ratio, surfactant concentration, kinds of electrolyte, ionic strength and mole numbers of oxyethylene additions to nonionic surfactant using $\alpha$-Fe$_2$O$_3$ particle as the model of particulate soil. The suspending power of anionic and nonionic surfactant mixed solution was relatively higher than that of anionic and nonionic surfactant single solution regardless of solution concentration. The suspending power was gradually decreased with increasing duration time of suspension. In the absence of electrolyte, the effect of surfactant concentration on suspending power was small but in solution with electrolyte, suspending power was lowest at 1 % surfactant concentration. With 1${\times}$10$^{-3}$ ionic strength and polyanionic electrolyte in solution, the suspending power was high but effects of oxyethylene mole number to nonionic surfactant on suspending power was small. Generally the suspending power was gradually increased with decreasing the particle size. Hence the suspending power was inversely related to the particle size.

Design and Analysis of Hybrid Stator Bearingless SRM

  • Lee, Dong-Hee;Ahn, Jin-Woo
    • Journal of Electrical Engineering and Technology
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    • v.6 no.1
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    • pp.94-103
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    • 2011
  • This paper presents a novel bearingless switched reluctance motor (BLSRM) with decoupled torque and suspending stator poles. BLSRM is different from conventional bearingless switched reluctance motors (SRMs) because its suspending poles are separated from the torque poles. Perpendicularly placed suspending poles are designed to produce a continuous radial force to suspend the rotor. Due to the independent suspending and torque poles, BLSRM produces a suspending force with excellent linearity according to the rotor position and independent characteristics of the torque current. The air-gap is easier to control than in conventional SRMs with their linear and independent characteristics. Furthermore, to verify the proposed structure, a mathematical model for the suspending force is derived. Finite element analysis is also employed to compare BLSRM and conventional SRMs expressions of suspending force. A prototype motoris designed and manufactured to verify the effectiveness of the proposed bearingless structure.

Effect of Dispersion Stability of Particles on Detergency of Particulate Soil(Part 1) - The Dispersion Stability of α-Fe2O3 Particles in the Nonyl Phenol Polyoxyethylene Ether Solution - (입자의 분산안정성이 고형오구의 세척성에 미치는 영향(제1보) - Nonyl Phenol Polyoxyethylene Ether 용액 내에서 α-Fe2O3 입자의 분산안정성 -)

  • Kang, In-Sook
    • Fashion & Textile Research Journal
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    • v.4 no.1
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    • pp.86-91
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    • 2002
  • To estimate dispersion stability of particles, suspending power and particle size were examined as functions of pHs, surfactants, electrolytes and ionic strengths using ${\alpha}-Fe_2O_3$ particle as the model of particulate soil. Suspending power and particle size were determined by UV-Vis spectrumeter and by light scattering using the polarization ratio method, respectively. The suspending power was relatively high with polyanion electrolytes and was low with neutral salts. The suspending power was biphasis, minimum pH 6~7, and the effect of surfactant on the suspending power was insignificant. Generally suspending power increased with decreasing the particle size governed aggregation of dispersed particles regardless of solution conditions. Hence the suspending power was inversely related to the particle size.

Characteristics Analysis of Suspending Force for Hybrid Stator Bearingless SRM

  • Ahn, Jin-Woo;Lee, Dong-Hee
    • Journal of Electrical Engineering and Technology
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    • v.6 no.2
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    • pp.208-214
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    • 2011
  • In this paper, a characteristics analysis and calculation of the suspending force of a novel bearingless switched reluctance motor (BLSRM) with hybrid stator poles is proposed. The operating principle and permeance are calculated to find an appropriate control scheme for a proposed motor. Furthermore, a mathematical model for suspending force is derived. Finite element analysis is also employed to compare with the expressions for suspending force. Finally, the validity of the structure and the mathematical model is verified by simulation results.

Suspending Force Control of 12/14 BLSRM Using Fuzzy Logic Controller (퍼지 논리 제어기를 사용한 축방향지지력 제어)

  • He, Yingjie;Zhang, Fengge;Ahn, Jin-Woo
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.845-847
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    • 2015
  • A suspending force control based on fuzzy logic control is proposed to apply on a novel hybrid bearingless switched reluctance motor(BLSRM) which has separated torque and suspending force pole. Due to the unique structure, the suspending force control system can be easily decoupled from torque control system. In this paper, two fuzzy controller targeted at x-axis direction and y-axis direction are adopted to maintain the shaft at center position, which is very necessary for stable operation of BLSRM. By replacing the traditional PI block with modified fuzzy logic controller, the suspending system can behave a good performance, and the proposed scheme can be verified by simulation results.

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A Design and Driving Characteristics of Novel Hybrid Pole Bearingless SRM (새로운 하이브리드 극 구조의 베어링리스 SRM 설계 및 운전특성)

  • Lee, Dong-Hee;Wang, Hui-Jun;An, Young-Joo;Ahn, Jin-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.12
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    • pp.2202-2207
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    • 2008
  • Bearingless SRM(Switched Reluctance Motor) is researched for high speed or special applications which can not use mechanical bearing such as bio pump. In this paper, a novel hybrid pole bearingless SRM is presented. The proposed hybrid pole bearingless SRM has salient poles for torque and suspending force production. Motor torque is controlled by the phase currents in torque pole windings, and the suspending force is controlled by suspending currents in four suspending windings for radial direction suspension. Because the proposed bearingless SRM has divided pole structure, mutual effects between torque current and suspending current are very lower than the conventional one's. From this structure, the number of power devices for power converter can be reduced for bearingless SRM driving. The proposed hybrid pole bearing less SRM is verified by the FEM analysis and experimental results.

Influence of Suspending Agents on the Bactericidal Action of Cationic Surfactants and Amphoteric Surfactants -Influence on the Bactericidal Action of Codecyl Diaminoethyl Glycine and Benzalkonium Chloride- (분산안정제가 cationic surfactant와 amphoteric surfactant의 살균력에 미치는 영향 Dedecyl Diaminoethyl Glycine 및 Benzalkonium Chloride의 살균력에 미치는 영향)

  • 이진환
    • YAKHAK HOEJI
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    • v.11 no.3_4
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    • pp.17-21
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    • 1967
  • At present, quarternary ammonium salts(cationic surfactant) and Tego compounds (amphoteric surfactant) are used as germicidal agent. In this paper, it was investigated whether their germicidal activities are influenced or not by some suspending agents which are added to them 0.005% benzalkonium chloride aq. solution and 0.05% dodecyl diaminoethyl glycine aq. solution sterilized respectively against Staphylococcus aureus and Escherichia coli within a minute. The solutions aded acacia, carboxymethyl cellulose, sodium alginate solutions to make to 0.005% to above surfactants solution decreased the germicidal activity, not being sterilized bacteria for more than 2 hours however, the solutions decreased the germicidal activity by addition of suspending agents such as acacia, carboxymethyl cellose, sodium alginate and bacteria were survival for more than 2 hrs, 0.05% of benzalkonium chloride and 0.1% dodecyl diaminoethyl glycine respectively would be sterilized within 10 minutes, when added to 5% suspending agents. This result show that bactericidal action of dodecyl diaminoethyl glycine is affected by suspending agents less than that of benzalkonium chloride.

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Suspending Force Control of New BLSRM Based on Fuzzy Controller (퍼지제어기 기반의 새로운 BLSRM의 축방향지지력 제어)

  • He, Yingjie;Zhang, Fengge;Lee, Donghee;Ahn, Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2015.11a
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    • pp.215-216
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    • 2015
  • A suspending force control based on fuzzy logic control is proposed to apply on a novel hybrid bearingless switched reluctance motor(BLSRM) which has separated torque and suspending force pole. In this paper, two fuzzy controller targeted at x-axis direction and y-axis direction are adopted to maintain the shaft at center position, which is very necessary for stable operation of BLSRM. Useing the modified fuzzy logic controller, the suspending system can behave a good performance, and the proposed scheme can be verified by simulation results.

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MULTIPLE SOLUTIONS FOR A SUSPENDING BEAM EQUATION AND THE GEOMETRY OF THE MAPPING

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
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    • v.17 no.2
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    • pp.211-218
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    • 2009
  • We investigate the multiple solutions for a suspending beam equation with jumping nonlinearity crossing three eigenvalues, with Dirichlet boundary condition and periodic condition. We show the existence of at least six nontrivial periodic solutions for the equation by using the finite dimensional reduction method and the geometry of the mapping.

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Suspending Commissural Sutures for Aortic Valve Exposure in Minithoracotomy Aortic Valve Replacement

  • Kim, Eunji;Kim, Joon Bum
    • Journal of Chest Surgery
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    • v.54 no.6
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    • pp.551-553
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    • 2021
  • Although it is attractive, a limitation of aortic valve (AV) replacement (AVR) through a mini-thoracotomy approach (mini-AVR) is the limited exposure of the AV. Here, we present a simple exposure technique named "suspending commissural sutures" for a more efficient mini-AVR. The technique involves making 3 half-depth stitches with 1-0 silk at each of the commissures, which are anchored to each corresponding pericardial surface. These stitches are tightened up so that the aortic root is axially expanded and is pulled upward. The technique of suspending commissural stitches seems to offer reasonable exposure of the AV in mini-AVR, and shows excellent early surgical outcomes.