• 한국정밀공학회지
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• 제15권6호
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• pp.145-152
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• 1998

This paper presents an optimum design of a rotor-bearing spindle system for a ultra centrifuge (80,000 RPM) supported by ball bearings with nonlinear stiffness characteristics. To obtain the nonlinear bearing stiffnesses, a ball bearing is modeled in five degrees of freedom and is analyzed quasi-statically. The dynamic behaviors of the nonlinear rotor-bearing system are analyzed by using a transfer-matrix method iteratively. For optimization. we use the cost function that simultaneously minimizes the weight of a rotor and maximizes the separation margins to yield the critical speeds as far from the operating speed as possible. Augmented Lagrange Multiplier (ALM) method is employed for the nonlinear optimization problem. The result shows that the rotor-bearing spindle system is optimized to obtain 9.5％ weight reduction and 21％ separation margin.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1977년도 제9회 학술발표회 초록
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• pp.109.4-109
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• 1977

• 한국산업정보학회논문지
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• 제17권1호
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• pp.1-9
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• 2012

본 논문은 태양전지용 실리콘 잉곳 절삭시 발생하는 폐 슬러지에서 실리콘, 연마재를 분리 회수 재사용하는 시스템에 관한 것이다. 분리시스템의 기본 공정은 다중원심분리이고 분리 효율을 높이기 위해 초음파 교반, 알코올 물 가수, 가열처리를 하였다. 실리콘의 경우 2N의 경우 96% 회수율을 보였고, 4N의 경우 94%의 회수율을 보였다. 연마재인 SiC의 경우에는 약 80%의 회수율을 보였다. 4N의 고순도 Si 회수를 위해서는 진공열처리를 수행하여 잔류성분을 제거하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.319-323
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• 1996

정격속도 80,000 rpm 초고속 원심분리기(ultra-centrifuge)의 회전체동역학 설계가 수행된다. 설계목표는 충분한 위험속도(critical speed)의 분리여유(separation margin)와 함께, 다수의 고차 위험속도 통과시 원심분리기 로터의 위치에서 양호한 불균형응답특성을 갖는 로터-베어링 시스템의 최적구성을 이루어 내는 것이다. 후자의 특성은 불균형에 의해 가진될 때 로터의 질량중심이 회전축에 가능한 한 근접하도록 함으로써 만족시킬 수 있으며, 이를 위해 초유연축(extra slender shaft)이 적용된다. 이와 더불어, 특히 1차 위험속도에서 공진에 기인한 로터의 큰 변위를 방지하기 위해 범퍼링(bumper ring) 또는 안내베어링(guide bearing)의 설치가 필요하다. 유한요소법(finite element method)에 의한 회전체동역학 모델링이 수행되며, 지지 구름베어링의 강성과 함께 소량의 감쇠(damping)가 고려된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.312-317
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• 1997

This paper present an optimum design for the rotor-bearing system of a high-speed (80000RPM) ultra-centrifuge supported by ball bearings with nonlinear stiffness characteristics. To obtain the nonlinear bearing stiffnesses, a ball bearing is modelled in five degrees of freedom and is analyzed quasi-statically. The dynamic behaviors of the nonlinear rotor-bearing system are analyed by using a transfer-matrix method iteratively. For optimum design, minimizing the weight of a rotor is used as a cost function and the Augmented Lagrange Multiplier (ALM) method is employed. The result shows that the rotor-bearing system is optimized to obtain 8% weight reduction.

• 한국재료학회지
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• 제19권10호
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• pp.527-532
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• 2009

The electrochromic properties of Au nanoparticles (NPs) incorporating poly (3, 4-ethylenedioxythiphene) (PEDOT) film were investigated. Trisodium citrate was used for stabilizing Au NPs to control the size. The capping molecules of the Au nanoparticles were exchanged from citrate to 2-mercaptoethanol (2-ME). Water was removed by centrifuge and Au NPs were redispersed in methanol (MeOH). Finally, we obtained ca. 11.7 nm diameter of Au NPs. The effects of 0.15 at% of Au NPs incorporation on the optical, electrical, and eletrochromic properties of PEDOT films were investigated. The electrical property and switching speed of Au/PEDOT film was slightly improved over that of PEDOT film because Au NPs play a hopping site role and affect packing density of the PEDOT chain. Through the ultra violet-visible spectra of PEDOT and Au/PEDOT films at -0.7 V (vs Ag/AgCl), blue shift of maximum absorption peak was observed from PEDOT (585.4 nm) to Au/PEDOT (572.2 nm) due to a shortening of conjugated length of PEDOT. The Au NPs interfered with the degree of conjugation and the maximum absorption peak was shifted to shorter wavelength.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2010년도 정기총회 및 춘계학술발표회
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• pp.14-14
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• 2010

Plastid proteomics are essential organelles present in virtually all cells in plants and green algae. Plastids are responsible for the synthesis and storage of key molecules required for the basic architecture and functions of plant cells. The proteome of plastid, and in particular of chloroplast, have received significant amounts of attention in recent years. Various fractionation and mass spectrometry (MS) techniques have been applied to catalogue the chloroplast proteome and its sub-organelles compartments. To better understanding the function of the lumenal sub-organelles within the thylakoid network, we have carried out a systematical analysis and identification of the lumenal proteins in the thylakoid of wheat by using Tricine-SDS-PAGE, and LTQ-ESI-FTICR mass spectrometry followed by SWISS-PROT database searching. We isolation and fractionation these membrane from fully developed wheat leaves using a combination of differential and gradient centrifugation couple to high speed ultra-centrifuge. After collecting all proteins to eliminate possible same proteins, we estimated that there are 407 different proteins including chloroplast, chloroplast stroma, lumenal, and thylakoid membrane proteins excluding 20 proteins, which were identified in nucleus, cytoplasm and mitochondria. A combination of these three programs (PSORT, TargetP, TMHMM, and TOPPRED) was found to provide a useful tool for evaluating chloroplast localization, transit peptide, transmembranes, and also could reveal possible alternative processing sites and dual targeting. Finally, we report also sub-cellular location specific protein interaction network using Cytoscape software, which provides further insight into the biochemical pathways of photosynthesis. The present work helps understanding photosynthesis process in wheat at the molecular level and provides a new overview of the biochemical machinery of the thylakoid in wheat.