• Title/Summary/Keyword: inter-laboratory study

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Genetic Diversity among Indian Oak Tasar Silkworm, Antheraea proylei J. Revealed by ISSR Markers

  • Devi, Kanghujam Ibsorani;Ponnuvel, Kangayam M.;Singh, Laishram Somen;Singh, Kangjam Chaoba;Dutta, Karabi
    • International Journal of Industrial Entomology and Biomaterials
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    • v.24 no.2
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    • pp.57-61
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    • 2012
  • The Indian Oak Tasar silkworm, Antheraea proylei J. is a beneficial insect with great economic importance in India for its silk production. In this study, six populations of Antheraea proylei and A. frithi Moore (as an out group) were subjected to inter simple sequence repeat (ISSR) marker analysis in order to assess its genetic diversity. Fifteen ISSR primers produced 91 markers among different breeds of A. proylei and A. frithi of which 89 are polymorphic, generating 97.8% polymorphism. The dendrogram constructed using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) and cluster analysis made using Nei's genetic distance resulted in the formation of one major group containing four sub-groups separating the breeds. This result suggests that ISSR amplification is potentially useful for molecular characterization of oak tasar silkworm genotypes.

Geotechnical behavior of a beta-1,3/1,6-glucan biopolymer-treated residual soil

  • Chang, Ilhan;Cho, Gye-Chun
    • Geomechanics and Engineering
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    • v.7 no.6
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    • pp.633-647
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    • 2014
  • Biopolymers, polymers produced by living organisms, are used in various fields (e.g., medical, food, cosmetic, medicine) due to their beneficial properties. Recently, biopolymers have been used for control of soil erosion, stabilization of aggregate, and to enhance drilling. However, the inter-particle behavior of such polymers on soil behavior are poorly understood. In this study, an artificial biopolymer (${\beta}$-1,3/1,6-glucan) was used as an engineered soil additive for Korean residual soil (i.e., hwangtoh). The geotechnical behavior of the Korean residual soil, after treatment with ${\beta}$-1,3/1,6-glucan, were measured through a series of laboratory approaches and then analyzed. As the biopolymer content in soil increased, so did its compactibility, Atterberg limits, plasticity index, swelling index, and shear modulus. However, the treatment had no effect on the compressional stiffness of the residual soil, and the polymer induced bio-clogging of the soil's pore spaces while resulting in a decrease in hydraulic conductivity.

Determination of Cadmium, Chromium and Lead in Polymers by ICP-OES Using a High Pressure Asher (HPA)

  • Cho, Hong-Je;Myung, Seung-Woon
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.489-497
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    • 2011
  • The proposed method for an effective assay of Cd, Cr and Pb in several polymer samples has been validated. The determination was carried out using ICP-OES after a high pressure asher (HPA) digestion at pressure and temperatures up to 13 MPa and $320^{\circ}C$, respectively. Polymer based materials were totally oxidized with nitric acid in a HPA chamber and determined by ICP-OES. Validation parameters such as linearity, matrix effect, limit of dectection (LOD), limit of quantitation (LOQ), accuracy and precision (repeatibility, intermediate precision and reproducibility) were assessed. The LOD and LOQ in the sample were ranged from 0.98 to 1.18 mg $kg^{-1}$ and 2.93 to 3.55 mg $kg^{-1}$, respectively, relying on the analyte. The proposed method had a good accuracy and precision for repeatability, intermediate precision with respect to days and analysts and reproducibility expressed as inter-laboratory study. The developed method was simple to use, suitable and applicable to various kinds of polymers.

POM/MICOM Inter-Comparison in Modeling the East Sea Circulation

  • Kim, Kuk-Jin;Seung, Young-Ho;Suk, Moon-Sik
    • Ocean and Polar Research
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    • v.23 no.2
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    • pp.161-172
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    • 2001
  • A model-to-model comparison is attempted between Princeton Ocean Model (POM) and Miami Isopycnic Coordinate Ocean Model (MICOM) as a first step to extend our knowledge of models' performances in studying the East Sea circulation. The two models have fundamentally different numerical schemes and boundary conditions imposed on these models are not exactly the same each other. This study indicates that MICOM has a critical weak point in that it does not reproduce the shallow surface currents properly while it handles the thermohaline processes and associated movements of intermediate and deep waters efficiently. It is suggested that the mixed layer scheme needs to be modified so that it can match with inflow boundary conditions in order to reproduce the surface currents properly in MICOM. POM reproduces the surface current pattern better than MICOM, although the surface currents in POM appear to undergo the unrealistic seasonal variation and have exaggeratedly large vertical scale. These defects seem to arise during the process of adapting POM to the East Sea, and removing these defects is left as a future task.

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Comparisons of Ocean Currents Observed from Drifters and TP/ERS in the East Sea

  • Lee, Dong-Kyu;Niiler, Pearn P.;Suk, Moon-Sik
    • Ocean and Polar Research
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    • v.23 no.2
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    • pp.133-139
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    • 2001
  • Ocean currents estimated from sea height anomalies derived from inter-calibrated TP/ERS are compared with daily mean currents measured with satellite-tracked drifters. The correlation coefficient between the geostrophic current from TP/ERS and surface current at 15 m depth from drifter tracks was found to be about 0.5. Due to the limitation of satellite ground tracks, small scale eddies less than 80 km are poorly resolved from TP/ERS. One of the interesting results of this study is that coastal currents along the eastern coast of Korea were well reproduced from sea height anomalies when the coastal currents were developed in association with eddies near the South Korean coast. The eddy kinetic energy (EKE) estimated from drifters, TP/ERS, and a numerical model are also compared. The EKE estimated from drifters was about 22 % higher than EKE calculated from TP/ERS. The pattern of low EKE level in the northern basin and high EKE level in the southern East Sea is shown in the EKE estimates derived from both the drifters and TP/ERS.

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A Study of Comparison Test for Brake Disk Lining (KRRI-CARS) (제동디스크라이닝의 비교시험 연구(KRRI-CARS))

  • Hong Yong-Ki;Chung Jong-Duk;Kwon Sung-Tae;Wang Jing-Bo
    • Proceedings of the KSR Conference
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    • 2003.10c
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    • pp.363-368
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    • 2003
  • The Inter-laboratory comparison test which is demanded on the authorized test of ISO 17025 is the program to guarantee the reliability for test results of test organization. In order to apply to the field of railway, brake disk lining as one of the railway components has been selected and the comparison test is executed for the purpose of guaranteeing the reciprocal reliability for the test result of both organizations and enlarging the substantial technique exchange of both nations by the standard establishment with test procedures and test programs from now on.

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Cyclotron Resonance of the Wannier-Landau Transition System Based on the Ensemble Projection Technique

  • Jung-Il Park
    • Journal of the Korean Magnetic Resonance Society
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    • v.27 no.4
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    • pp.28-34
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    • 2023
  • We study the linear-nonlinear quantum transport theory of Wannier-Landau transition system in the confinement of electrons by a square well confinement potential. We use the projected Liouville equation method with the ensemble density projection technique. We select the dynamic value under a linearly oscillatory external field. We derive the dynamic value formula and the memory factor functions in three electron phonon coupling systems and electron impurity coupling systems of two transition types, the intra-band transitions and inter-band transitions. We obtain results that can be applied directly to numerical analyses. For simple example of application, we analyze the absorption power and line-widths of ZnO, through the numerical calculation of the theoretical result in the Landau system.

A Dynamic Offset and Delay Differential Assembly Method for OBS Network

  • Sui Zhicheng;Xiao Shilin;Zeng Qingji
    • Journal of Communications and Networks
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    • v.8 no.2
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    • pp.234-240
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    • 2006
  • We study the dynamic burst assembly based on traffic prediction and offset and delay differentiation in optical burst switching network. To improve existing burst assembly mechanism and build an adaptive flexible optical burst switching network, an approach called quality of service (QoS) based adaptive dynamic assembly (QADA) is proposed in this paper. QADA method takes into account current arrival traffic in prediction time adequately and performs adaptive dynamic assembly in limited burst assembly time (BAT) range. By the simulation of burst length error, the QADA method is proved better than the existing method and can achieve the small enough predictive error for real scenarios. Then the different dynamic ranges of BAT for four traffic classes are introduced to make delay differentiation. According to the limitation of BAT range, the burst assembly is classified into one-dimension limit and two-dimension limit. We draw a comparison between one-dimension and two-dimension limit with different prediction time under QoS based offset time and find that the one-dimensional approach offers better network performance, while the two-dimensional approach provides strict inter-class differentiation. Furthermore, the final simulation results in our network condition show that QADA can execute adaptive flexible burst assembly with dynamic BAT and achieve a latency reduction, delay fairness, and offset time QoS guarantee for different traffic classes.

HPLC Analysis of Organic Acids, Phenol, and Benzopyrene in Wood Vinegar (HPLC에 의한 목초액 중의 유기산, 페놀 및 벤조피렌의 분석법 개발)

  • Lee, Gye-Won;Kim, A-Ram;Cho, Jae-Soo
    • YAKHAK HOEJI
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    • v.52 no.1
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    • pp.12-19
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    • 2008
  • The organic acids (formic acid, acetic acid and propionic acid), phenol and benzopyrene in wood vinegar were determine by HPLC. An $Atlantis^{TM}dC_{18}$ column with a acetonitrile: 0.1% phosphoric acid (5: 95, organic acids), acetonitrile: water (10 : 90, phenol), 100% acetonitrile (benzopyrene) as a mobile phase was used. Retention time of acetic acid, formic acid, propionic acid, phenol and benzopyrene was 4.77, 3.73, 9.08, 30.97 and 6.10 min, respectively. The calibration curves of organic acids, phenol, benzopyrene were linear over the concentration range of $30{\sim}500,\;60{\sim}1000$, and $3{\sim}50\;{\mu}g/ml$ with correlation coefficient of above 0.999. The limit of detection (LOD) and limit of quantitation (LOQ) of acetic acid, formic acid, propionic acid, phenol, and benzopyrene was 1.71 and 5.19, 1.11 and 3.35, 4.87 and 14.74, 6.45 and 19.55, 0.08 and $0.24\;{\mu}g/ml$, respectively. The coefficients of variation for intra- and inter-day assay were $0.21{\sim}4.14$ and $0.07{\sim}1.19%$, respectively and the precision was $95{\sim}115%$. From this study, we suggest that HPLC is suitable method for the determination of organics in wood vinegar and could be applied to quality control of wood vinegar.

2010 Inter-laboratory Comparison Study on Nutrient Analysis in Seawater (2010년 국내 해수 중 영양염 분석 실험실간 상호비교실험 연구)

  • Moon, Cho-Rong;Rho, Taekeun;Kang, Dong-Jin;Kahng, Sung-Hyun;Cho, Sung Rok;Kim, Eun-Soo;Lee, Jung Moo;Park, Eun Ju;Shin, Jin-Sun
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.20 no.1
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    • pp.63-70
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    • 2015
  • An inter-laboratory comparison campaign on nutrient analysis in seawater was carried out in 2010. Sets of three sterilized seawater samples (Bottle 130, 131, 132) which have enough homogeneity and stability were distributed to 10 laboratories. Participants analyzed the nutrients in their own laboratories (nitrite, nitrate, phosphate, and silicate) at least 5 times and reported the results. Statistical treatments were applied to the results to assess the precision for each laboratory and the discrepancy among laboratories. Most laboratories show within 10% of precision in all nutrient results. Degrees of scattering described as discrepancy among laboratories and relative percent difference values were 4~63% and 0.04~2217%, respectively. The statistical analysis shows that the difference among the laboratories may due to the systematic error rather than random error. When the results were corrected by the results of bottle 130 as a reference material, the degrees of scattering and the relative percent difference were improved significantly. As a result, since most participants show satisfactory precision for nutrient analyses, a use of reference materials which have homogeneity and stability was strongly recommended to improve the comparability of nutrient data.