• Title/Summary/Keyword: Standard solution

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Determination of Bi Impurity in Lead Stock Standard Solutions by Hydride-generation Inductively Coupled Plasma Mass Spectrometry

  • Park, Chang J.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.2
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    • pp.233-236
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    • 2004
  • Total impurity analysis of a primary standard solution is one of the essential procedures to determine an accurate concentration of the standard solution by the gravimetry. Bi impurity is determined in Pb standard solutions by inductively coupled plasma mass spectrometry (ICP-MS). The direct nebulization of the Pb standard solution produces a significant amount of the Pb matrix-induced molecular ions which give rise to a serious spectral interference to the Bi determination. In order to avoid the spectral interference from the interferent $^{208}PbH^+$, the hydride generation method is employed for the matrix separation. The Bi hydride vapor is generated by reaction of the sample solution with 1% sodium borohydride solution. The vapor is then directed by argon carrier gas into the ICP after separation from the mixture solution in a liquid-gas separator made of a polytetrafluoroethylene membrane tube. The presence of 1000 ${\mu}$g/mL Pb matrix caused reduction of the bismuthine generation efficiency by about 40%. The standard addition method is used to overcome the chemical interference from the Pb matrix. Optimum conditions are investigated for the hydride-generation ICPMS. The detection limit of this method is 0.5 pg/mL for the sample solutions containing 1000 ${\mu}$g/mL Pb matrix.

Uncertainty in Determination of Menthol from Mentholated Cigarette (담배 중 멘톨 분석에 대한 불확도 측정)

  • 장기철;이운철;백순옥;한상빈
    • Journal of the Korean Society of Tobacco Science
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    • v.22 no.1
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    • pp.91-98
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    • 2000
  • This study was carried out to evaluate the uncertainty in the analysis of menthol content from the mentholated cigarette. Menthol in the sample cigarette was extracted with methanol containing an anethole as an internal standard, and then analyzed by gas chromatography. As the sources of uncertainty associated with the analysis of menthol, were the following points tested, such as the weighing of sample, the preparation of extracting solution, the pipetting of extracting solution into the sample, the preparation of standard solution, the precision of GC injections for standard & sample solution, the GC response factor of standard solution, the reproducibility of menthol analysis, and the determination of water content in tobacco, etc. For calculating the uncertainties, type A of uncertainty was evaluated by the statistical analysis of a series of observation, and type B by the information based on supplier's catalogue and/or certificated of calibration. Sources of uncertainty were subsequently included and mathematically combined with the uncertainty arising from the assessment of accuracy to provide the overall uncertainty. It was shown that the main source of uncertainty came from the errors in the reproducibility of menthol and water determination, the purity of menthol reference material in the preparation of standard solution, and the precision of GC injections for sample solution. The errors in sample weighing and volume measurement contributed relatively little to the overall uncertainty. The expanded uncertainty in the mentholated cigarettes, Korean and American brand, at 0.95 level of statistical confidence was $\pm$0.06 and $\pm$0.07 mg/g for a menthol content of 1.89 and 2.32 mg/g, respectively.

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Uncertainty of Total Alkaloids and Reducing Sugar Determination in Flue-cured Tobacco (황색종 담배중 전알카로이드와 환원당 분석에 대한 불확도 측정)

  • 백순옥;장기철;이운철;한상빈
    • Journal of the Korean Society of Tobacco Science
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    • v.23 no.1
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    • pp.45-52
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    • 2001
  • This study was carried out to evaluate the uncertainty in the analysis of total alkaloids and reducing sugar content in flue-cured tobacco. The sources of uncertainty associated with the analysis of total alkaloids and reducing sugar were the weighing of sample, the preparation of extracting solution, the addition of extracting solution into the sample, the preparation of standard solution, the precision of calibration curve for standard solution, the reproducibility of analysis, and the determination of water content in tobacco, etc. For the calculating uncertainties, Type A of uncertainty was evaluated by the statistical analysis of a series of observation, and Type B by the information based on supplier’s catalogue and/or certificated of calibration. It was shown that the main source of uncertainty was caused by the calibration curve of standard solution, the reproducibility of analysis, the volume measurement of 1$m\ell$, and the purity of nicotine reference material in the preparation of standard solution. The uncertainty in the addition of extracting solution, the sample weighing, the volume measurement of 100$m\ell$, and the determination of water content of tobacco contributed relatively little to the overall uncertainty. The expanded uncertainty of total alkaloids and reducing sugar in flue-cured tobacco at 95% level of confidence was $\pm$0.12% and $\pm$0.54%, respectively.

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Development of Adoption Strategy and Guideline of Business Process Management Standards: Focusing on Business Process Execution Language (비즈니스 프로세스 관리 표준 도입 전략 및 지침 개발: 비즈니스 프로세스 실행 언어를 중심으로)

  • Kim, Dong-Soo
    • Journal of Information Technology Services
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    • v.5 no.2
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    • pp.107-123
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    • 2006
  • The objectives of this study is to develop a strategy for the adoption of BPM(Business Process Management) standards and an implementation guideline of the BPM standard for BPM solution developers focusing on BPEL(Business Process Execution Language) which is regarded as the most important BPM standard. In the heterogeneous and distributed IT environments, every type of enterprise software requires standards to enhance interoperability. BPMS(Business Process Management System), which is a type of enterprise software requires BPM standards such as BPEL(Business Process Execution Language), BPMN(Business Process Modeling and Notation), BPQL(Business Process Query Language) and so on to achieve multi-system interoperability and component interoperability with their BPM solutions. It is quite helpful to provide the adoption strategy concerning BPM standards for each type of BPM solution vendors who need the BPM standards. Since the BPEL is conceived as the most important BPM standard and widely adopted by many BPM vendors, we have proposed a reference architecture for BPEL implementation and also developed the detail implementation guideline of core components of the BPM system supporting the BPEL standard. Using the strategy and implementation guideline proposed in this work, BPM solution vendors can establish their own standard adoption strategy and they can also develop their BPM solutions supporting the BPM standards more efficiently.

The controversial points for the assessment of soil contamination related to the change of pH of extraction solution in using partial extraction in standard method in Korea (국내 토양오염 공정시험방법의 용출법 사용시 용출액의 pH의 변화가 토양 오염 평가에 미치는 문제점)

  • 오창환;유연희;이평구;이영엽
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.294-297
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    • 2000
  • Heavy metals are extracted from Chonju stream sediment, roadside soils and sediments along Honam expressway, soils and tailings from mining area using partial ectraction in Standard Method, partial ectraction method with maintaining 0.1N of extraction solution and acid digestion. In samples having buffer capacity against acid, 0.1N of extraction solution can not be maintained and pH of extraction solution increases up to 8.0 when partial extraction in Standard Method is used. The averages and ranges of (heavy metals extracted using partial extraction in standard method, HPE)/(heavy metals extracted using partial extraction method with maintaining 0.1N of extraction solution, HPEM) values are 0.506 and 0.145~1.126 in Cd, 0.534~ and 0.078~0.928 in Zn, 0.461 and 0.041~1.715 in Mn, 0.359 and 0.011~0.874 in Cu, 0.195 and 0.018~1.785 in Cr, 0.710 and 0.003~3.075 in Pb, and 0.088 and 1.73$\times$10$^{-5}$ ~0.303 in Fe. These data indicate that the difference between HPE and HPEM is big in the order of Fe, Cr, Cu, Mn, Cd, Zn and Pb. It is quite possible that the partial extraction method in Standard Method of soil in Korea is not adequate for an assessment of contamination in area where buffer capacity of soil will be decreased or lost after a long term exposure of soils to environmental damage.

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Report on the Stability of Freeze-dried Standard Solution (동결건조표준액의 안정성에 관한 보고)

  • Park, Jun Mo;Yoo, Hye Jung;Kim, Han Chul;Han, Geul Soon
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.2
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    • pp.139-148
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    • 2012
  • Purpose : Since standard solution is the one that knows its exact concentration, the curve of the dissolution has been determined according to the amount of the solution, compared to the amount of the unknown sample. Therefore, the antigen that makes up standard materials should be made in a pure form. The configuration of the standard substance solution in the kit we use is a freeze-dried material, or made and comes as a liquid. Lyophilized reference material is used after dissolving in usually D.W. (Distilled Water), and if the antigen to use is too sensitive, reagents should be freeze-dried. Furthermore, when freeze-dried reference has to be frozen again after being dissolved, it should be kept under $-20^{\circ}C$ until the expiration date according to the reports. Since it is not expressed in the experiment if it is safe or stable to reuse the solution which was dissolved a few times, thus, this time it is tested and evaluated that the changes of the standard solution by freezing and melting several times, and its results and the effectiveness of it were compared to the solution which was kept in a fridge. Materials and Methods : Among Vitro diagnostic kits on the market made by radioimmunoassay, parathyroid hormone (PTH), adrenocorticotropic hormone (ACTH), luteinizing hormone (LH) are made of freeze-dried standard solution and all composed of the same Lot.NO. These hormones melted in D.W. and were separated into three groups. In the first group, melting and freezing were repeated, and in the second group, The solution only for one time use was put into a test tube after melting and freeze it. The third group was kept in the refrigerator. This experiment has been conducted from January to February in 2012. January to 2012. PH test was employed because ph is prone to changing depending on the change of protein. Each group of the standard solution, cpm (counter per minute), and the patient relative concentration values were compared by date, and Through the correlation coefficient and Paired t-test, the significant level of each group was analyzed. Results : ACTH, PTH, LH pH values were too subtle denaturation rather than numerical changes in the protein. In addition, when the standard solution of ACTH, PTH, LH was refrigerated, after 3 days and 7 days, there was a significant difference observed between the solution being kept in a refrigerator and a freezer within a significance level. Conclusion : Standard solution should be kept in a freezer, and being kept in a fridge, it is recommended to use the solution as soon as possible.

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Development of the EAI Solution Selection Criteria : Focused on the case of KRA (EAI(Enterprise Application Integration) 도입을 위한 평가기준 개발 적용에 관한 연구 : KRA 적용사례 중심으로)

  • Juhn Sung-Hyun;Park Chan Uk
    • Journal of Information Technology Applications and Management
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    • v.12 no.4
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    • pp.157-171
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    • 2005
  • Recently companies are aggressively Pushing ahead with integrating the systematical applications of internal and external information systems such as Data level, Application level, Process level in the company, Process level between companies. The EAI solution is generally considered as the necessary tool to integrate companies, but the appraisal standard for the EAI solution has not Vet settled in Korea, so the companies have difficulty in deciding whether to adopt the EAI solution or not. Through this report, we first introduce the KRA Project as the best practice in making an application of the settled standard to evaluate and adopt the EAI solution, and then suggest that it can be adapted to companies considering applying to the EAI solution.

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A GENERALIZED 4-STRING SOLUTION TANGLE OF DNA-PROTEIN COMPLEXES

  • Kim, Soo-Jeong
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.15 no.3
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    • pp.161-175
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    • 2011
  • An n-string tangle is a three dimensional ball with n strings properly embedded in it. A tangle model of a DNA-protein complex is first introduced by C. Ernst and D. Sumners in 1980's. They assumed the protein bound DNA as strings and the protein as a three dimensional ball. By using a tangle analysis, one can predict the topology of DNA within the complex. S.Kim and I. Darcy developed the biologically reasonable 4-string tangle equations and decided a solution tangle, called R-standard tangle. The author discussed more about the simple solution tangles of the equations and found a generalized R-standard tangle solution.

Coupling Finite Elements and Analytical Solution for Electromagnetic Field Analysis (유한요소법과 해석석의 응합에 의한 전자동 연구)

  • 김은배;양재면;이기식;유동일
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.4
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    • pp.362-368
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    • 1992
  • This paper presents a coupling scheme, which couples an analytical solution and the standard finite element, for analyzing the electromagnetic fields. The former is a solution of the magnetic field in free space, i.e., the outer region of boundary, and the latter represents the system with source currents and magnetic materials in the inner region of boundary. The proposed method retains the sparsity and symmetry of the final system matrix, the merits of the standard FEM. To verify the usefulness of the proposed algorithm, an example which can be solved analytically is chosen and analyzed. The results are compared with those of the standard FEM and the analytic solutions.

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Sensing NO3-N and K Ions in Hydroponic Solution Using Ion-Selective Membranes (이온선택성 멤브레인을 이용한 양액 내 질산태 질소 및 칼륨 측정)

  • Kim, Won-Kyung;Park, Tu-San;Kim, Young-Joo;Roh, Mi-Young;Cho, Seong-In;Kim, Hak-Jin
    • Journal of Biosystems Engineering
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    • v.35 no.5
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    • pp.343-349
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    • 2010
  • Rapid on-site sensing of nitrate-nitrogen and potassium ions in hydroponic solution would increase the efficiency of nutrient use for greenhouse crops cultivated in closed hydroponic systems while reducing the potential for environmental pollution in water and soil. Ion-selective electrodes (ISEs) are a promising approach because of their small size, rapid response, and the ability to directly measure the analyte. The capabilities of the ISEs for sensing nitrate and potassium in hydroponic solution can be affected by the presence of other ions such as calcium, magnesium, sulfate, sodium, and chloride in the solution itself. This study was conducted to investigate the applicability of two ISEs consisting of TDDA-NPOE and valinomycin-DOS PVC membranes for quantitative determinations of $NO_3$-N and K in hydroponic solution. Nine hydroponic solutions were prepared by diluting highly concentrated paprika hydroponic solution to provide a concentration range of 3 to 400 mg/L for $NO_3$-N and K. Two of the calibration curves relating membrane response and nutrient concentration provided coefficients of determination ($R^2$) > 0.98 and standard errors of calibration (SEC) of < 3.79 mV. The use of the direct potentiometry method, in conjunction with an one-point EMF compensation technique, was feasible for measuring $NO_3$-N and K in paprika hydroponic solution due to almost 1:1 relationships and high coefficients of determination ($R^2$ > 0.97) between the levels of $NO_3$-N and K obtained with the ion-selective electrodes and standard instruments. However, even though there were strong linear relationships ($R^2$ > 0.94) between the $NO_3$-N and K concentrations determined by the Gran's plot-based multiple standard addition method and by standard instruments, hydroponic $NO_3$-N concentrations measured with the ISEs, on average, were about 10% higher than those obtained with the automated analyzer whereas the K ISE predicted about 59% lower K than did the ICP spectrometer, probably due to no compensation for a difference between actual and expected concentrations of standard solutions directly prepared.