• Title/Summary/Keyword: micro-component

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Headspace Hanging Drop Liquid Phase Microextraction and GC-MS for the Determination of Linalool from Evening Primrose Flowers

  • Kim, Nam-Sun;Jung, Mi-Jin;Yoo, Zoo-Won;Lee, Sun-Neo;Lee, Dong-Sun
    • Bulletin of the Korean Chemical Society
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    • v.26 no.12
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    • pp.1996-2000
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    • 2005
  • Headspace hanging drop liquid phase micro-extraction (HS-HD-LPME) is studied as a novel solvent-based sample pretreatment method for floral volatile aroma compounds. This paper reports on application of the HSHD- LPME combined with GC-MS for the analysis of linalool component emitted from evening primrose flowers. The effect of several variables on the method performance was investigated. Additionally, the separation of enantiomers on a cyclodextrin capillary column was performed to identify chirality of (−)-linalool component. Since the unsurpassed volume of a few micro-liters of solvent is used, there is minimal waste or exposure to toxic organic solvents. This method enables to combine extraction, enrichment, clean-up, and sample introduction into a single step prior to the chromatographic process.

A study on design of assembly and evaluation system for optical micro film filter (필름형 마이크로 광필터 조립 평가 시스템 설계에 관한 연구)

  • 최두선;제태진;황경현;박한수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1191-1194
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    • 2003
  • At present, the fabrication of optical filter for optical communication mostly depends on handwork, and only a few companies are propelling semi-automatic systems compounded with automatic and hand-operated methods. The measurement evaluation of optical filters is not commonly useful, so it causes difficulties in the producing field. And the packaging process becomes a very unstable process because the filters are judged from the results that they are not measured and immediately packaged during that process. In this situation, the automatic assembly system of optical filter for communication is extremely important and has begun to make its appearance as the most necessary technology for developing optical communication component with high-functionality. In this paper, we constructed systems of assembly and performance evaluation for micro optical collimator. And by using that, we designed a system capable of performance evaluation and assembly of film filter of about 30 $\mu\textrm{m}$ thickness as well as optical filter for common communication.

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Mechanical Property of Photocurable Hydrogel Fiber by Light Intensity (빛의 강도에 따른 광경화성 하이드로겔 섬유의 기계적 물성)

  • Lee, Sangmin;Chu, Bokyeong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.10
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    • pp.38-43
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    • 2021
  • Photocurable hydrogels are widely used as 3D printing materials in tissue engineering (e.g., scaffold fabrication) as well as optical fibers (or optical sensors) materials. Photocurable hydrogels can control optical and mechanical properties such as chemical or fabrication conditions. In previous research, we introduced a new 3D printing method to fabricate a freestanding overhanging hydrogel structure without supporting structure. This study was measured and analyzed the difference of the mechanical properties of the photocurable hydrogel according to the light intensity using a micro tensile tester. In practically, it was difficult to perform a direct tensile test on a micro (less than 1 mm) size fiber. In this study, the tensile test of the hydrogel fibers could be measured simply and repeatedly using a paper carrier.

Development of Distributed Micro Turbine Co-generation System (분산형 마이크로 터빈 열병합 발전시스템 개발)

  • Kwon, Gi-Hun;Kim, Seung-Woo;Lee, See Woo
    • 유체기계공업학회:학술대회논문집
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    • 2002.12a
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    • pp.320-327
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    • 2002
  • In concert with the growing emphasis placed on distributed power generation there will be a need, in the first decade of the 21th century, for a compact thermal energy system capable of providing the total energy needs of individual homes. A natural gas fueled co-generation micro-turbine with ultra low emission will meet this need. Market opportunities for a distributed micro turbine co-generation system are projected to increase dramatically. In this paper, It was determined that with current state of art component performance levels, metrallic materials, thermal efficiency goal of $28\%$ at sea level standard day conditions are attainable. Higher overall thermal efficiency of $78\%$ is attainable with micro-turbine combined with exhaust fired boilers.

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Analysis of Design and Operation Performance of Micro Gas Turbine : Part 1 - Performance Analysis Program (마이크로 가스터빈 설계 및 운전 성능 분석 : 제1부 - 성능해석 프로그램)

  • Kim, Jeong Ho;Kang, Do Won;Kim, Tong Seop
    • The KSFM Journal of Fluid Machinery
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    • v.18 no.4
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    • pp.22-29
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    • 2015
  • In this study, an in-house program to predict steady state operation of micro gas turbines is constructed using MATLAB. The program consists of two parts: design and off-design simulations. The program is fully modular in its structure, and performance of each component (compressor, combustor, turbine, recuperative heat exchanger and pipe elements) is calculated in a separate calculation module using mass and energy balances as well as models for off-design characteristics. The off-design modules of compressor and turbine use performance maps, which are program inputs. The off-design operation of a micro gas turbine under development was predicted by the program. The prediction results were compared with those by commercial software, and the validity of the in-house program was confirmed.

Optimization of Passive Mixer for Enhanced Mixing in a Micro-channel by Using Lattice Bloltzmann Method (격자 볼츠만 방법을 이용한 미소 채널에서의 혼합효율 증가를 위한 수동형 믹서의 최적화)

  • Han Gyu suk;Byun Sung Joon;Yoon Joon Yong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.5 s.236
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    • pp.707-715
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    • 2005
  • In this work, Scalar Passive code in Lattice Boltzmann Method is employed to simulate two-phase flow of low Reynolds number in a micro-channel. The mixing characteristics in a micro-channel is a function of Peclet number. The mixing length increases with the Peclet number. It is found that with the inclusion of static elements at the channel, rapid mixing of two liquids can be achieved, as shown by the results of computer simulations. The enhancement in mixing performance is thought to be caused by the generation of eddies and by lateral velocity component when the mixture flows past static elements. The results indicate that the size of static element has more effect on the mixing than the number of static element.

Micro-mechanical modeling for compressive behavior of concrete material

  • Haleerattanawattana, P.;Senjuntichai, T.;Limsuwan, E.
    • Structural Engineering and Mechanics
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    • v.18 no.5
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    • pp.691-707
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    • 2004
  • This paper presents the micro-mechanical modeling for predicting concrete behavior under compressive loading. The model is able to represent the heterogeneities in the microstructure up to three phases, i.e., aggregate particles, matrix and interfaces. The smeared crack concept based on non-linear fracture mechanics is implemented in order to formulate the constitutive relation for each component. The splitting tensile strength is considered as a fracture criterion for cracking in micro-level. The finite element method is employed to simulate the model based on plane stress condition by using quadratic triangular elements. The validation of the model is verified by comparing with the experimental results. The influence of tensile strength from both aggregate and matrix phases on the concrete compressive strength is demonstrated. In addition, a guideline on selecting appropriate tensile strength for each phase to obtain specified concrete compressive strength is also presented.

Fabrication and Test of a Micro Passive Liquid Pressure Regulator (초소형 수동형 유체 압력 조정기 제작 및 실험)

  • Lee, Ki-Jung;Lim, In-Ho;Sim, Woo-Young;Yang, Sang-Sik
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1482-1483
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    • 2008
  • This report describes the design, fabrication and experimental results of an implantable micro pressure regulator. It consists of three silicon substrates, a glass substrate, and a PDMS layer. Silicon and glass substrates are fabricated by using bulk micro machining and sandblasting. The PDMS layer is used as a intermediate layer for Si-Si and Si-glass bonding processes. This micro regulator is a key component of the portable drug delivery systems for low power consumption. The device has some advantages, such as a passive type device, no power consumption, and simple structure.

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Design and Prototyping Micro Centrifugal Compressor for Ultra Micro Gas Turbine

  • Hirano, Toshiyuki;Tsujita, Hoshio;Gu, Ronglei;Minorikawa, Gaku
    • International Journal of Fluid Machinery and Systems
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    • v.2 no.4
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    • pp.426-430
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    • 2009
  • In order to investigate the design method for a micro centrifugal compressor, which is the most important component of an ultra micro gas turbine, an impeller having the outer diameter of 20mm was designed, manufactured and tested. The designed rotational speed is 500,000 rpm and the impeller has a fully 3-dimensional shape. The impeller was rotated at 250,000 rpm in the present study. The experimental results of the tested compressor with the vaned and the vaneless diffusers were compared. It was found that the vaned diffuser attained the higher flow rate than the vaneless diffuser at the maximum pressure ratio. In addition the maximum pressure ratio was higher for the diffuser having a larger diffuser divergence angle at the high flow rate. These results were compared with those obtained by the prediction method used at the design stage.