• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.32-37
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• 2005

The procedure of soil sampling for on-farm quick test of soil nitrate is very important to improve practical application without weighing or drying soil. To improve application of test strip reflectometer as a quick on-farm analytical procedure for the estimation of soil nitrate concentration, three sampling methods such as gravimetric sampling (GS), particle density sampling (PDS) and bulk density sampling (BDS) for on-farm analytical procedure were investigated with twelve soils of 45 to $281mg\;kg^{-1}$ nitrate nitrogen concentration. The nitrate nitrogen concentrations measured from different soils were compared with two analytical methods, ion electrode method as a standard laboratory analysis (SLA) and test strip reflectometer at three moisture conditions, viz. air dried soil, 20 and 40% of maximum water holding capacity (MWHC). Nitrate nitrogen concentration measured by test strip reflectometer was significantly correlated with that of SLA, and the coefficients of variation (CV) were in the range of 3.5 to 10.9%. These CV values less than 10.9% were thought to be acceptable for the measurement of soil nitrate as an on-farm real time analytical procedure. The nitrate nitrogen concentration by BDS for test strip reflectometer as well as ion electrode method was more similar to that of SLA compared with those by GS and PDS especially in case of moist soils. This result suggests that the BDS is more useful than GS and PDS in case of on-farm analytical procedure of soil nitrate for moist soils. Further the practical measurement by BDS could be improved by substituting the bottle cap with a larger container.

• Structural Engineering and Mechanics
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• v.12 no.2
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• pp.135-156
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• 2001

Analytical solutions and finite element results of laminated composite plates with smart material layers embedded in them are presented in this study. The third-order plate theory of Reddy is used to study vibration suppression characteristics. The analytical solution for simply supported boundary conditions is based on the Navier solution procedure. The velocity feedback control is used. Parametric effects of the position of the smart material layers, material properties, and control parameters on the suppression time are investigated. It has been found that (a) the minimum vibration suppression time is achieved by placing the smart material layers farthest from the neutral axis, (b) using thinner smart material layers have better vibration attenuation characteristics, and, (c) the vibration suppression time is larger for a lower value of the feedback control coefficient.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.456-463
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• 2005

An analytical procedure to analyze reinforced concrete (RC) beams subject to monotonic loadings is proposed on the basis of the moment-curvature relations of RC sections. Unlike previous analytical models which result the overestimation of stiffnesses and underestimation of structural deformations induced from ignoring the shear deformation and assuming perfect-bond condition between steel and concrete, the proposed relation considers the rigid-body-motion due to anchorage slip at the fixed end. The advantages of the proposed relation, compared with the previous numerical models, are on the promotion in effectiveness of analysis and reflection of influencing factors which must be considered in nonlinear analysis of RC beam by taking into account the nonlinear effects into the simplifying moment-curvature relation. Finally, correlation studies between analytical and experimental results are conducted to establish the applicability of the proposed model to the nonlinear analysis of RC structures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.2
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• pp.23-29
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• 1989

The strain rate-sensitive constitutive models of steel and concrete were incorporated into a refined analytical procedure for loading rate-dependent axial/flexural analysis of reinforced concrete beam-columns. The predictions of the analytical technique compared well with both quasi-static and dynamic test results on reinforced concrete elements.

• Journal of Korean Association for Spatial Structures
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• v.2 no.3 s.5
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• pp.115-122
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• 2002

It is often hard to obtain analytical solutions of boundary value problems of shells. Introducing some approximations into the governing equations may allow us to get analytical solutions of boundary value problems. Instead of an analytical procedure, we can apply a numerical method to the governing equations. Since the governing equations of shells of revolution under symmetric load are expressed by ordinary differential equations, a numerical solution of ordinary differential equations is applicable to solve the equations. In this paper, the governing equations of orthotropic spherical shells under symmetric load are derived from the classical theory based on differential geometry, and the analysis is numerically carried out by computer program of Runge-Kutta methods. The numerical results are compared to the solutions of a commercial analysis program, SAP2000, and show good agreement.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.1
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• pp.25-30
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• 2007

In this study, the two sampling methods for blood glucose measurement were evaluated in order to reduce pre-analytical error. For this purpose, glucose levels of Li-heparinized plasma (LHP) and Na-fluorinated plasma (NFP) in blood collected from healthy volunteers were determined by using routine hexokinase procedures. The percentage range of pre-analytical error was quantitated by comparing LHP glucose values with NFP glucose values according to delaying analytical time (0, 60, and 120 min). LHP glucose values were decreased by 6.6% in 60 min., 17.7% in 120 min, whereas NFP glucose values decreased by 1.1% in 60 min, 2.0% in 120 min. Therefore it may be recommended that the NFP sampling method should be used for routine blood glucose determination in diabetes mellitus diagnosis.

• Analytical Science and Technology
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• v.18 no.6
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• pp.520-528
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• 2005

Two biological Certified Reference Materials (CRMs), KRISS 108-04-001 (oyster tissue) and 108-05-001 (water dropwort stem), were prepared by Korea Research Institute of Standards and Science (KRISS)during FY '01. The certified values of these materials had been determined by Isotope Dilution Mass Spectrometry (IDMS) for six elements (Cd, Cr, Cu, Fe, Pb and Zn). Additional analytical works are now progressing to certify the concentrations of a number of the environmental and nutrimental elements in these CRMs. The certified values in a CRM are usually determined by using a single primary method with confirmation by other method(s) or using two independent critically-evaluated methods. Instrumental Neutron Activation Analysis (INAA) plays an important role in the determination of certified values as it can eliminate the possibility of common error sources resulting from sample dissolution. In this study INAA procedure was used in determination of 23 elements in these two biological CRMs to acquire the concentration information and the results were compared with KRISS certified values.

• FOCUS: LIFE SCIENCE
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• no.1
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• pp.8.1-8.3
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• 2024

Ultra-high performance liquid chromatography (UHPLC) systems are integral to modern analytical laboratories, necessitating careful maintenance and operation protocols to ensure optimal performance. This document provides comprehensive guidelines for the proper shutdown and reactivation of UHPLC systems to prevent damage and maintain operational efficiency. • Shutdown: Remove the column and replace it with a union to avoid blockages. Flush the system with a compatible solvent mix, clean mobile phase reservoirs to prevent microbial growth, flush the pump with storage solvent, and clean the autosampler, including the needle and injection port. • Reactivation: Inspect the system for wear or damage, gradually reintroduce mobile phases starting with a weak solvent, reinstall the column securely, and perform system checks on baseline stability, pressure consistency, and detector performance. By adhering to these guidelines, laboratories can ensure the longevity and reliability of their UHPLC systems, maintaining high analytical performance and minimizing downtime. These procedures help prevent common issues such as blockages, contamination, and component wear, thereby supporting efficient and accurate analytical operations.

• Computers and Concrete
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• v.19 no.3
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• pp.283-291
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• 2017

A large number of residential buildings in regions subjected to severe earthquakes do not have enough load carrying capacity. The most of them have been constructed without receiving any structural engineering attention. It is practically almost impossible to perform detailed experimental evaluation and analytical analysis for each building to determine their seismic vulnerability, because of time and cost constraints. This fact points to a need for a simple evaluation method that focuses on selection of buildings which do not have the life safety performance level by adopting the main requirements given in the seismic codes. This paper deals with seismic assessment of existing reinforced concrete residential buildings and contains an alternative simplified procedure for seismic evaluation of buildings. Accuracy of the proposed procedure is examined by taking into account existing 250 buildings. When the results of the proposed procedure are compared with those of the detailed analyses, it can be seen that the results are quite compatible. It is seen that the accuracy of the proposed procedure is about 80% according to the detailed analysis results of existing buildings. This accuracy percentage indicates that the proposed procedure in this paper can be easily applied to existing buildings to predict their seismic performance level as a first approach before implementing the detailed and complex analyses.

• Computers and Concrete
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• v.6 no.4
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• pp.305-318
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• 2009

Fiber Reinforced Polymer (FRP) is widely used for retrofitting concrete structures for various purposes. Especially, for the retrofitting of concrete structures subjected to blast loads, FRP is proven to be a very effective retrofitting material. However, a systematic design procedure to implement FRP for concrete structure retrofitting against blast loads does not exist currently. In addition, in case of concrete structures with inarticulate geometrical boundary conditions such as arch structures, an effective analysis technique is needed to obtain reliable results based on minimal analytical assumptions. Therefore, in this study, a systematic and efficient blast analysis procedure for FRP retrofitting design of concrete arch structure is suggested. The procedure is composed of three sequential parts of preliminary analysis, breach and debris analysis, and retrofit-material analysis. Based on the suggested procedure, blast analyses are carried out by using explicit code, LS-DYNA. The study results are discussed in detail.