• Title, Summary, Keyword: Analytical method

Search Result 6,887, Processing Time 0.063 seconds

Rapid analytical method of the polychlorinated biphenyls in PCBs containing liquid wastes (PCBs 함유 액상폐기물의 신속분석방법 고찰)

  • Shin, Sun-Kyoung;Jeon, Tae Wan;Yoon, Jeong-Ki;Kim, Tae-Seung;Oh, Gi Jong;Kim, Young Shik;Kim, Kyoung Soo
    • Analytical Science and Technology
    • /
    • v.21 no.3
    • /
    • pp.174-182
    • /
    • 2008
  • The study on the development of rapid analytical method of PCBs containing waste was performed by considering the extraction, column cleanup process, analytical condition and so on. In the established method, new sample clean-up procedure, new quantification peaks and temperature program were introduced. Method detection limit of the method was 0.5 mg/L, and the method could save the total run time to 2/3, therefore save the analysis cost, The new rapid analytical method of transformer oil was suggested to the waste official test method.

Analytical Fragility Curves for Bridge (교량의 해석적 손상도 곡선)

  • Lee, Jong-Heon
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.3 no.4
    • /
    • pp.155-162
    • /
    • 1999
  • This paper presents a generation of analytical fragility curves for bridge. The analytical fragility curves are constructed on the basis of nonlinear dynamic analysis. Two-parameter lognormal distribution functions are used to represent the fragility curves with the parameters estimated by the maximum likelihood method. To demonstrate the development of analytical fragility curves, two of representative bridges with a precast prestressed continuous deck in the Memphis. Tennessee area are used.

  • PDF

Finite Element Analysis Using an Analytical Solution (해석해를 이용한 유한 요소 해석법)

  • Huh, Young-Woo;Lim, Jang-Keun
    • Proceedings of the KSME Conference
    • /
    • /
    • pp.458-463
    • /
    • 2000
  • The mechanical structures generally have discontinuous parts such as the cracks, notches and holes owing to various reasons. In this paper, in order to analyze effectively these singularity problems using the finite element method, a mixed analysis method which an analytical solution and finite element solutions are simultaneously used is newly proposed. As the analytical solution is used in the singularity region and the finite element solutions are used in the remaining regions except this singular zone, this analysis method reasonably provides for the numerical solution of a singularity problem. Through various numerical examples, it is shown that the proposed analysis method is very convenient and gives comparatively accurate solution.

  • PDF

Comparison of analytical method of headspace and tenax analysis for residue of solvent amounts on plastic packaging materials (Headspace 방법과 tenax 방법을 이용한 잔존 용제 분석 방법의 비교)

  • An, Duek-Jun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
    • /
    • v.10 no.1
    • /
    • pp.63-68
    • /
    • 2004
  • The regulations for migration amounts in USA, EU and Korea are investigated to compare the actual overall and specific migration date from plastic food packaging materials. Among the packaging materials regulated in above countries, printing ink solvents on packaging materials is used very widely and sometimes cause off-flavor in the food by migration of residual solvents. Even though migration of the residual solvents dose not generally cause safety problems in the contained food, it certainly can generate off-flavor and finally deteriorate quality of the finished product. Therefore regulation and development of analytical method for amount of residual ink solvents are very important issue in food industry. The headspace analytical method and tenax method for residual ink solvent on food packaging materials were evaluated from the accuracy, precise, swiftness and convenience of viewpoint. Headspace analytical method was selected and recommended for using in food industry field.

  • PDF

Analytical approximate solutions for large post-buckling response of a hygrothermal beam

  • Yu, Yongping;Sun, Youhong
    • Structural Engineering and Mechanics
    • /
    • v.43 no.2
    • /
    • pp.211-223
    • /
    • 2012
  • This paper deals with large deformation post-buckling of a linear-elastic and hygrothermal beam with axially nonmovable pinned-pinned ends and subjected to a significant increase in swelling by an alternative method. Analytical approximate solutions for the geometrically nonlinear problem are presented. The solution for the limiting case of a string is also obtained. By coupling of the well-known Maclaurin series expansion and orthogonal Chebyshev polynomials, the governing differential equation with sinusoidal nonlinearity can be reduced to form a cubic-nonlinear equation, and supplementary condition with cosinoidal nonlinearity can also be simplified to be a polynomial integral equation. Analytical approximations to the resulting boundary condition problem are established by combining the Newton's method with the method of harmonic balance. Two approximate formulae for load along axis, potential strain for free hygrothermal expansion and periodic solution are established for small as well as large angle of rotation at the end of the beam. Illustrative examples are selected and compared to "reference" solution obtained by the shooting method to substantiate the accuracy and correctness of the approximate analytical approach.

Food safety analytical techniques used in food industry (식품산업에서 활용되는 식품안전 분석기술의 현황)

  • Kim, Young-Jun
    • Food Science and Industry
    • /
    • v.51 no.1
    • /
    • pp.16-25
    • /
    • 2018
  • Recently, the importance of analytical techniques related to food safety is emerging in the food industry due to changes in diet patterns, environmental changes, climate change and consumer's interest in food safety. In particular, food safety accidents in the food industry may cause economic losses such as media reports, product recalls, consumer distrust, and so on. Therefore, a systematic, proactive and comprehensive food safety management system is increasingly required to prevent food safety issues. Efforts to ensure the reliability of food safety are essential by introducing various analysis instruments such as LC, GC, ICP, LC/MS/MS, GC/MS/MS, ICP/MS, PCR, and RT-PCR. In addition, recent food safety analytical techniques used in food industry should be shifted paradigm by developing multi-component simultaneous analytical method, low cost with high efficient analytical method, and eco-friendly method.

Characteristic Analysis of Axial-gap Motor using Magnetic Charge (Magnetic charge를 이용한 Axial-gap 전동기의 특성해석)

  • Lee, Sang-Ho;Kim, Do-Jin;Hong, Jung-Pyo
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.997-998
    • /
    • 2007
  • This paper deals with analytical solution concerning the image method using the magnetic charge instead of 3D FEA(finite element analysis) in the slotless single air-gap motor. The theory of analytical method and the design procedures are introduced. The reliability and validity of proposed analytical solution are verified through the comparison with the results of commercial 3D FE software. In addition, calculation time between proposed analytical solution and 3D FEA is compared. Finally, characteristics, such as Back-EMF and phase resistance, between calculated and experimental results are compared. From the verification with 3D FEA and experimental results, it is proved that presented analytical method provided very effective and precise results.

  • PDF

Isolation and Quantitative Determination Method Validation of myristicin from Myristica fragrans Houttuyn (육두구(Myristica fragrans Houttuyn) 내의 myristicin의 분리 및 HPLC를 이용한 함량분석 방법 밸리데이션)

  • Kim, Soo-Hwan;Lee, Dong-Ho;Kwon, Soo-Han;Lim, Buyng-Ho;Lee, Sang-Hun;Min, Bum-Chan
    • Korean Journal of Pharmacognosy
    • /
    • v.38 no.1
    • /
    • pp.19-21
    • /
    • 2007
  • Myristica fragrans has been used for the treatment of stomachache in East Asia. It is very important to determine the amount of myristicin in Myristica fragrans, because excess myristicin causes side effects. In this study, we developed and validated the method for determination contents of myristicin in Myristica fragrans which was purchased from various regions of Korea. The average content of myristicin in Myristica fragrans was 2.10% with the validated HPLC analysis method.

Parametric Analysis of Tubular-Type Linear Magnetic Couplings with Halbach Array Magnetized Permanent Magnet by Using Analytical Force Calculation

  • Kim, Chang-Woo;Choi, Jang-Young
    • Journal of Magnetics
    • /
    • v.21 no.1
    • /
    • pp.110-114
    • /
    • 2016
  • Magnetic couplings are widely used in various industrial applications because they can transmit magnetic force without any mechanical contact. In addition, linear couplings have many advantages. For example, they do not need to convert rotary motion to linear motion. This paper shows an analytical analysis of tubular type linear magnetic couplings (TLMCs) with a Halbach array magnetized permanent magnet (PM). An analytical method for magnetic fields owing to PMs is performed by using magnetic vector potential as well as Poisson and Laplace equations. Then, the magnetic force is calculated by using the Maxwell stress tensor. The analytical analysis results were compared with finite element method (FEM) results. In addition, we predicted the magnetic force characteristic according to design parameters such as the iron core thickness, inner PM thickness to -outer PM thickness ratio, PM segment ratio of the axial magnetized PM segment and radial magnetized PM segment, and various pole numbers.

Analytical method for the out-of-plane buckling of the jib system with middle strut

  • Wang, T.F.;Lu, N.L.;Lan, P.
    • Steel and Composite Structures
    • /
    • v.21 no.5
    • /
    • pp.963-980
    • /
    • 2016
  • The jib system with middle strut is widely used to achieve the large arm length in the large scale tower crane and the deployability in the mobile construction crane. In this paper, an analytical solution for the out-of-plane buckling of the jib system with middle strut is proposed. To obtain the analytical expression of the buckling characteristic equation, the method of differential equation was adopted by establishing the bending and torsional differential equation of the jib system under the instability critical state. Compared with the numerical solutions of the finite element software ANSYS, the analytical results in this work agree well with them. Therefore, the correctness of the results in this work can be confirmed. Then the influences of the lateral stiffness of the cable fixed joint, the dip angle of the strut, the inertia moment of the strut, and the horizontal position of the cable fixed joint on the out-of-plane buckling behavior of the jib system were investigated.