• 제목/요약/키워드: standard calibration

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Rapid Analysis of Melamine Content in Powdered and Liquid Milk Using Fourier Transform Infrared Spectroscopy

  • Wang, Jun;Jun, Soo-Jin;Li, Qing X.
    • Food Science and Biotechnology
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    • 제18권5호
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    • pp.1199-1203
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    • 2009
  • Melamine is a chemical intermediate to manufacture amino resins and plastics, which cannot be used as food additive since it can cause kidney stones. A qualitative determination method of melamine residue in powdered and liquid milk was developed using Fourier transform infrared (FTIR) spectroscopic technique. The calibration sets consisted of 21 standard melamine solutions, in which 1% trichloroacetic acid aqueous solution and acetonitrile (3:1, v/v) were used as solvent. The model was validated using 10 standard melamine solutions which were unused to build up the calibration set. Infrared (IR) absorbance peaks specific to almost all chemical groups in melamine molecule were shown in the spectral range between 1,100 and 1,800/cm. Combined partial least squares (PLS)-$2^{nd}$ derivative calibration model coupled with mean centering (MC) mathematical enhancement showed the highest correlation coefficients ($R^2$>0.99). In brief, the FTIR technique can be used for quantitative analysis of melamine in milk samples.

국가교정검사기관(액체유량)의 측정불확도 평가 및 비교연구 (A Study on the Evaluation of Measurement Uncertainty for the National Calibration and Test Organizations (Liquid Flow))

  • 임기원
    • 설비공학논문집
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    • 제12권11호
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    • pp.1012-1019
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    • 2000
  • A proficiency test is one of programs which Korea Research Institute of Standards and Science(KRISS), as national metrology institute, is putting in operation for the mutual recognition arrangement. The Fluid Flow Group of KRISS evaluated the measurement capability for liquid flowmeter calibrator of the national calibration and test organizations. The uncertainty of national standard system was estimated in accordance with Guide to The Expression of Uncertainty in Measurement (ISO), and the turbine flowmeter, which was used for the round-robin test as a reference flowmeter, was characterized. The round-robin tests with the turbine flowmeter package were carried out in 1995 and 1999. The test results of the organizations and those of KRISS agreed within $\pm0.2$%. It is found thus that the organizations have the traceability of the national standard for liquid flow measurement.

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기름 유량표준장치의 개발 및 측정 불확도에 관한 연구 (A Study on the Development and the Uncertainty Analysis of Oil Flow Standard System)

  • 임기원;최종오
    • 대한기계학회논문집B
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    • 제27권8호
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    • pp.1071-1080
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    • 2003
  • A national standard system was developed in order to calibrate and test the oil flowmeters for the petroleum field. A stop valve and a gyroscopic weighing scale were employed for the primary standard of the flow quantity. It is operated by the standing start and finish mode and the static weighing method. The model equation for uncertainty evaluation was based on the calibration principle of standard system. The sources of the uncertainties were quantified and combined according to the GUM(Guide to the Expression of Uncertainty in Measurement). It was found that the standard system had the relative expanded uncertainty of 0.04 % in the range of 18 - 350 ㎥/h. According to the uncertainty budget, the uncertainties of the fluid density and the volume of pipeline, which were temperature dependent, contributed 92% of final uncertainty in the oil flow standard system.

평판형 와전류 표준 시험편의 개발 및 교정 (Development and Calibration of a Plate Type Eddy Current Standard)

  • 김영주;김영길;안봉영;윤동진
    • 비파괴검사학회지
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    • 제27권5호
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    • pp.393-397
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    • 2007
  • 절대형 와전류 탐촉자 인증 시험에 사용되는 인공 결함이 포함된 와전류 표준 시편을 개발하였다. 개발된 표준 시편은 ASTM E 1629에서 규정한 전기 전도도를 지니고 인공 결함을 포함하며 전체 형상과 규격, 인공 결함의 규격을 만족한다. 인공 결함의 규격은 너비 0.1 mm, 깊이 0.5 mm이다. 이 인공 결함은 기존에는 양 측 끝단만 측정이 가능하고 중간 부위의 측정이 불가능하여 가운데 부위의 인증이 불가능하였으나 초음파 기술을 적용하는 새로운 방법을 도입하여 $15\;{\mu}m$ 정도의 불확도로 측정을 하여 교정이 가능하도록 하였다.

방사성 중성자선원에 의한 방사선방어측정기의 교정을 위한 표준 중성자 조사장치 연구 (Standard Neutron Irradiation Facility for Calibration of Radiation Protection Instruments by Radioactive Neutron Sources)

  • 최길웅;이경주;황선태
    • Journal of Radiation Protection and Research
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    • 제14권1호
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    • pp.66-70
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    • 1989
  • 방사성 중성자선원은 일상적 시험에 있어 표준 중성자 방사선장을 형성하는데 적합하다. 방사선 방어상의 목적으로 사용되는 중성자 측정기기의 교정을 위한 기준 방사선이 ISO TC-85에서 제의되었다. 한국표준연구소 방사선연구실에는 ISO TC-85의 추천사항에 준하여 개인용 중성자 선량계를 교정하기 위하여 $^{252}Cf$$^{241}Am-Be$ 선원을 이용한 표준조사시설을 설립하였다. 본 연구에서는 중성자 산란과 선원 비등방성에 연관된 교정상의 보정인자들을 실험에 의하여 결정하였다.

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SgrA* 22/43GHz KaVA observation and its Amplitude Calibration

  • CHO, ILJE;JUNG, TAEHYUN;ZHAO, GUANG-YAO;KINO, MOTOKI;SOHN, BONGWON
    • 천문학회보
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    • 제41권1호
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    • pp.73.2-73.2
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    • 2016
  • We present the results of KaVA SgrA* observation together with Takahagi(32m), Yamaguchi(32m) and Nobeyama(45m) telescopes at 22 and 43GHz, respectively. In early 2014, G2 cloud was expected to encounter with SgrA* and to make a significant flux variation, but it has not been measured yet. So it's worth to check our amplitude calibration method to confirm if we have a missing flux caused by uncertainty in measuring it. We have tested both a standard method using system noise temperature(Tsys) with antenna gain information, and a template method in order to calibrate antenna gain using nearby maser source. As a result, we found that the latter method is useful for antennas which have inaccurate gain information or poor Tsys measurements, and is especially effective for sources at low elevation like SgrA*. In addition, the comparison shows that the amplitude calibration by standard method can be improved up to 10% with a correction factor using a template method. This result implies we can get more accurate flux from a standard method when any maser source not exists around target.

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H-UV 무습수 오프셋 인쇄에서 CMS 적용에 관한 연구 (Study on CMS Application in Hybrid UV Waterless Off-Set Printing)

  • 구철회;조가람
    • 펄프종이기술
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    • 제45권5호
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    • pp.1-13
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    • 2013
  • This study found fit optimum C, M, Y, K solid density and $CIEL^*a^*b^*$ value to paper & ink as well as check about printing machine state for color management in H-UV waterless off-set printing first. These values applied to GRACoL G7 calibration method. This method is one of color standard management method of printing. GRACoL G7 calibration method is possible stable tone reappearance by controlling gray balance by NPDC(Natural Printing Density Curve). Also, this study used values to make device profile as result that is gotten by application of GRACoL G7 calibration method. This profile was applied to CMS(Color Management System) of H-UV waterless off-set printing, and the result was possible by color management that correspond in printing quality standard of ISO 12647-2 and GRACol 2006 specifications.

Studies on pharmaceutical assay method using Near Infrared Spectroscopy (NIRS) (II)

  • Kang, Shin-Jung;Yun, Mi-Ok;Lee, Su-Jung;Choi, Hyun-Chul;Kim, Ho-Jeong;Kim, Ji-Yeon
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.4113-4113
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    • 2001
  • This study developed effective assay method of pharmaceutical quality control was developed by near-infrared spectroscopy (NIRS). The calibration equation model of assay was developed by 2nd deriviative PLS(Partial Least Squares) regression method with NIRS over the wavelength range from 1100 to 1400nm using diazepam tablets (2mg, 5mg). Although diazepam tablets are made by 5-different manufacture, they have similar formulation. When the correlation was compared with values by NIRS and HPLC, the R-2s and standard error of calibration (SEC) for 2mg were 0.9300 and 0.98%, the R-2s and SEC for 5mg were 0.9165 and 0.63%. The validation of the calibration equation model yield that the R-2s and standard error of prediction (SEP) for 2mg were 0.9611 and 0.995%, the R-2s and SEP for 5mg were 0.9114 and 0.842%. The method was validated on assay method for diazepam tablets by the calibration equation.

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