• Title/Summary/Keyword: chemical pump

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A Study on plans for improving localization of process pumps for petrochemical plants (석유화학 플랜트용 프로세스 펌프의 국산화율 제고 방안에 관한 연구)

  • Cho, Won-Bae;Moon, Seung-Jae;Yoo, Hoseon
    • Plant Journal
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    • v.5 no.3
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    • pp.50-58
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    • 2009
  • In this paper, the present condition for localization of process pumps and the enhancement method of the localization ratio of process pumps for refinery and chemical plant market were studied. The market of plant industry in the world has grown rapidly since 2000. However, the profit of domestic plant EPC compaies cound not have been increased as much as the market scale because they procured most of equipment from overseas. To make remarkable profit of plant EPC companies in the petrochemical industry, localization of equipments is required. Suitable equipment for localization is process pump applied API 610 standard. An purchased amount of pumps from overseas by domestic plant EPC companies in the last two years were 230 billion won. If process pumps are localized then an profit of plant EPC project will increase.

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The Orientation of CO in Heme Proteins Determined by Time-Resolved Mid-IR Spectroscopy: Anisotropy Correction for Finite Photolysis of an Optically Thick Sample

  • Lim, Man-Ho
    • Bulletin of the Korean Chemical Society
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    • v.23 no.6
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    • pp.865-872
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    • 2002
  • A systematic way of determining the equilibrium orientation of carbon monoxide (CO) in heme proteins using time-resolved polarized mid-IR spectroscopy is presented. The polarization anisotropy at pump-probe delay time of zero in the limit of zero photolysis and the angular distrbution function of CO are required to obtain the equilibrium orientation of CO. An approach is developed for determining the polarization anisotropy in the zero-photolysis limit from the anisotropy measured under finite photolysis conditions in an optically thick sample where the fraction of molecules photolyzed decreased as the pump pulse passes through and is absorbed by the sample. This approach is verified by measuring the polarization anisotropy of CO of carbonmonoxy myoglobin at various levels of photolysis. This method can be readily applied to other photoselection experiments determining precise angle between transition dipoles.

Performance Characteristics with Various Fuel Composition and Temperature for an External Type Fuel Pump in LPLi System (LPLi 시스템에서 외장형 펌프의 연료조성 및 온도에 따른 성능특성 연구)

  • Nam, Deok-Woo;Yoon, Jun-Kyu;Lim, Jong-Han
    • Journal of Advanced Marine Engineering and Technology
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    • v.35 no.5
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    • pp.566-575
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    • 2011
  • Since LPG (Liquefied petroleum gas) fuel supply system has an advantage of low emission characteristics, many studies have been conducted. In spite of the advantage of LPG supply system, a higher vapor pressure and lower viscosity than diesel or gasoline fuel may cause unstable running of fuel pump by the deterioration in lubrication performance and chemical reaction with rubber parts than that of diesel and gasoline fuel. Therefore its physical properties can cause the deterioration of durability. In this research, we developed an external type LPG pump which has the advantage of the price competitiveness and the convenient maintenance for LPLi system. The experiments were carried out in order to assess characteristics of the external type fuel pump at different fuel composition and temperature. As a result, there aren't any differences between internal and external type pump performance. It is observed that the same level of efficiency was maintained for both pumps as flow rate was increased with higher fuel temperature and more contents of propane in the fuel. And the pressure difference in LPLi system is maintained at constant with the various fuel compositions and temperatures due to their own characteristics of fuel supply system.

Fabrication and Test of a Micro Pump with a Magnetostrictive diaphragm (자기변형 박막을 이용한 마이크로 펌프의 제작과 시험)

  • Seo, Jee-Hoon;Jeong, Ok-Chan;Yang, Sang-Sik
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.1017-1019
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    • 1998
  • In this paper, the fabrication of a micropump with two giant magnetostrictive films of Sm-Fe and Tb-Fe is presented. The pump consist of one silicon wafer and one cover glass. The micropump consists of an actuator diaphragm, a paired nozzle and diffuser, and two through holes. The Structure of the micropump is fabricated by the chemical vapor deposition, the etching and the sputtering of the magnetostrictive films. The deflection of the actuator measured diaphragm is measured by using the laser vibrometer and the flow rate of the micro pump is observed by using a video microscope.

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The Retention and Chemical Composition of NVOCs (Natural volatile organic compounds) in a Warm Temperate Forest (난대림의 NVOCs 잔존량 및 성분 특성)

  • Sujin, Jang;Dohyun, Ryu;Kiwan, An
    • Journal of Environmental Science International
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    • v.31 no.11
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    • pp.901-910
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    • 2022
  • The aim of this study was to investigate the amount (i.e., retention volume) and chemical composition of Natural volatile organic compounds (NVOCs) across different sites in a temperate forest. The three forest sites that were considered include riparian zones (site 1), streams (site 2), and densely-canopied areas (site 3). From May to October 2021, a mini pump was used to measure the collected NVOCs. These measurements were conducted once a month, from 10:30 am to 11:30 am; these times encompass peak visitation times. In the tree layers of the site 1 and 2, Quercus acuta was dominant, whereas Camellia japonica dominated their subtree layers. On the other hand, the tree layer of site 3 was dominated by Castanopsis sieboldii, whereas Camellia japonica dominated its subtree layer. The retention volume and chemical composition of NVOCs was as follows: benzaldehyde (107.528ppm), α-pinene (37.868ppm), linalool (16.258ppm), eucalyptol (14.818ppm), and sabinene hydrate (14.679ppm). In particular, the retention volume of benzaldehyde decreased as temperature increased. In contrast, the retention volume of α-pinene increased as the temperature increased. The differences in forest topography across the studies sites were in the following order: riparian area> forest area> stream area.

Development of Multi-Chemical Supply System for Semiconductor Wafer Cleaning Station

  • Chung, Myung-Jin;Song, Young-Wook
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1309-1312
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    • 2005
  • A multi-chemical supply system is developed and applied to a wet station, which uses the multi-chemical process in one bath. To control the concentration of two chemicals, control logic of a supply pump is programmed using the programable logic controller (PLC). By using the multi-chemical supply system, wet station with single bath is applied to cleaning process using multi chemicals such as buffed oxide etchant (BOE) and standard clean 1 (SC-1). The concentration of each chemical is measured in the bath to verify the multi-chemical supply system. The control range in the each chemical concentration is measured to 1.33weight% in NH4OH and 0.23weight% in H2O2. The multi-chemical supply system can be movable and usable as an independent module of fixed wet station. By simply midifying the PLC, a multi-chemical supply system can be developed for a wet station.

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Introduction of Modifying Solvents to Carbon Dioxide in Supercritical Extractions

  • 이정미정;David J. Chesney
    • Bulletin of the Korean Chemical Society
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    • v.19 no.12
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    • pp.1351-1355
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    • 1998
  • A simple apparatus for adding a modifying solvent to supercritical CO2 extractant was described. Small, fixed volumes (typically 100 μL) of liquid modifying solvents were delivered during the extraction process by use of an in-line high pressure loop injector and an air pump. Without disconnecting the extraction cell from the supercritical fluid extraction system, the modifying solvent was repeatedly delivered. The solvent modification device was optimized during the extraction of carbaryl and bis(acetylacetonato) copper(Ⅱ). Extraction recoveries from spiked filter paper and soil samples ranged between 22% and 109%, depending on the analyte and matrix components. The addition of polar modifying solvents were necessary to improve the extractability of the nonpolar CO2.