• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.121-130
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• 2012

In analyzing pesticide residue, LLE (liquid liquid extraction) is generally applied as one of the existing methods, but needed quite a lot of organic solvents and analytical apparatuses for the sample pre-treatment. In addition to its long analysis time and complex analytical processes, it is required to develop a more rapid and efficient method at present. In order to establish an economic and simple pesticide residue analytical method, this study carried out a comparative experiment on the existing analytical method with a new sample pre-treatment method named QuEChERS (quick, easy, cheap, effective, rugged and safe), which extracts and refines pesticide components by directly adding solid powder into the sample. Both the two analytical methods showed favorable values of correlation coefficient ($R^2$ > 0.99) of calibration curves. In terms of the detection limit (identification limit), imidacloprid showed 0.02 mg/kg, while the rest of pesticides showed a level around 0.05 mg/kg. The results of this experiment revealed that the recovery of LLE was 92.8-100.9% and the RSD was below 2.5%. On the other hand, the recovery of QuEChERS was 92.2-101.6% and RSD was below 1.9%. As a result of comparing the amount of pesticide residue by the time between the two analytical methods by using Paired t-Test, there was no significant difference between the two analytical methods as the p-value ranged from 0.3148-0.9890. Considering the results of the two methods, the QuEChERS method had similar recovery, compared to the analytical method using the existing LLE, and the analytical time was shortened by about one fourth of that of the existing method. Moreover, since it excludes the use of harmful organic solvents like dichloromethane during the process of extraction, thus leading to protecting experimenters health and remarkably reducing the amount of disused solvents, it is judged as an echo-friendly and economic analytical method.

• Mycobiology
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• v.30 no.3
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• pp.117-127
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• 2002

Cleistothecial development in Aspergillus nidulans(teleomorph, Emericella nidulans) was examined with the transmission electron microscopy. Cleistothecial initial was a small coiled lump of cells, ca. 6 ${\mu}m$ in diameter, which was consisted of a slightly swollen core with a short "tail" hypha. Initials were wrapped with a loose layer of hyphae. Core cells of cleistothecial initials were broad and multinucleated at first, then formed dikaryotic ascogenous cells, followed by post-meiotic tetra-nucleate or octa-nucleate protoasci and finally mature ascospores. Croziers were formed early during cleistothecium development. The peridial layer of mature cleistothecia was derived from the wrapping hyphae which originally invested the young cleistothecium. Completion of peridial layers development was associated with the depositing of a non-enzyme reactive material around peridial cells. $H\ddot{u}lle$ cell formation during the cleistothecial development appeared to be somewhat coordinated with the developmental stages of cleistothecium.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.272-274
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• 2008

일반적으로 프탈레이트 에스테르의 전처리방법에는 액액추출법(Liquid Liquid Extraction, LLE), 고상추출법(Solid Phase Extraction, SPE), 고상미세추출법(Solid Phase Micro Extraction, SPME) 등의 분석방법이 있다. 그 중에서 본 연구에서는 간편하고 정확성이 높은 SPE를 이용하였으며, 적은 양의 유기용제를 사용하여 전처리함으로써 2차적인 환경 오염을 줄일 수 있다는 점에서 다른 전처리 방법보다 유용하다고 할 수 있다. 또한 프탈레이트 에스테르의 경우는 구조적으로 안정적인 편이나 페놀류의 경우 hydroxy group 때문에 GC/MS 분석시 유도체화 과정이 필수적이나 이번 연구에서는 HPLC를 이용하므로 별도의 유도체화의 번거로움 없이 바로 분석할 수 있는 이점이 있다. 더 많은 연구가 필요하겠지만 앞서서의 결과에서도 알 수 있듯이 전반적으로 검출한계가 0.1$\sim$0.5$\mu$g/L 정도로 높고, 82% 이상의 양호한 회수율을 나타낸 것으로 미루어 보아 극미량 분석이 아닌 이상, 산업체에서 HPLC의 이용이 더욱 유리할 것이라고 사료된다.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.54-57
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• 2006

Structure H formation experiments were conducted in a semi-batch stirred vessel using methane as the small guest substance and neohexane(NH), tert-butylmethylether(TBME) and methylcyclohexane(MCH) as the large molecule guest substance (LMGS). The results indicate that the rates of gas uptake and induction times are generally dependent on the magnitude of the driving force. When tert-butyl methyl ether is used as the LMGS rapid hydrate formation, much smaller induct ion time and rapid decomposition can be achieved. Liquid-liquid equilibrium (LLE) data for the above LMGS with water have been measured under atmospheric pressure at 275.5, 283.15K, and 298.15K. It was found that TBME is the most water soluble followed by NM and MCH. The solubility of water in the non-aqueous liquid was found to increase in the following order: MCH

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.4
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• pp.155-179
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• 2001

Bei der vorliegenden Arbeit geht es in erster Linie urn die Frage, ob das Kooprationsprinzip und die Konversationsmaximen von Grice als universale Prinzipien angenommen werden $k\"{o}nnen$. Diese Fragestellung $erw\"{a}chst$ aus der Beobachtung, $da{\ss}$ Grices Prinzipien in manchen $F\"{a}llen$ des Sprachgebrauches nicht als universal geltend erscheinen. Solche $F\"{a}lle$ finden sich vor allem in der Werbesprache, beim geschlechtsunterschied1ich betrachteten Sprachgebrauch und im Bereich der sozio-kulturell bedingten Kontexte des Sprachgebrauchs. In derartigen $F\"{a}llen\;haben\;n\"{a}mlich$ die konkreten Zwecke des Sprachgebrauches $Priorit\"{a}t$ vor sprachtheoretischen Prinzipien. Die $\"{U}berlegungen$ der vorliegenden Abhandlung zeigen nun, dass wir es dabei im Einzelfall zwar mit sehr unterschiedlichen und fallspezifischen Spracherscheinungen zu tun haben, dass diese sich aber mit Hilfe von ethnolinguistischen Untersuchungen $schlie{\ss}lich$ dennoch als Parameter unter universalen Prinzipien $erkl\"{a}ren$ lassen.

• Biomedical Science Letters
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• v.10 no.4
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• pp.507-514
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• 2004

The Pseudomonas aeruginosa isolated from the clinical specimens has a mutation on the QRDR (quinolone resistance determining region). There were obvious mutations in both gyrA and parC gene which are major targets of quinolone. Simultaneous mutations were found two sites or more on these genes in all of ten strains. GyrB or parE gene had only silent mutation without converted amino acids. We confirmed that P. aeruginosa from clinical specimens exhibited decreased sensitivity to fluroquiolone due to changed Thr-83→lle and Asp-87→Asn types on gyrA and altered Ser-87→Leu type on parC. This is the first finding that a new Met-93→Thr type on parC as well as mutations on gyrB or parE genes differed from existing patterns. This study showed more mutations of gyrA rather than parC, suggesting that change of Type Ⅳ topoisomerase is more serious than that of type Ⅱ (DNA gyrase).

• Korean Journal of Computational Design and Engineering
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• v.19 no.1
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• pp.68-79
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• 2014

Human model simulation has been widely used in various industrial areas such as ergonomic design, product evaluation and characteristic analysis of work-related musculoskeletal disorders. However, the process of building digital human models and capturing their behaviors requires many costly and time-consuming fabrication iterations. To overcome the limitations of this expensive and time-consuming process, many studies have recently presented a markerless motion capture approach that reconstructs the time-varying skeletal motions from optical devices. However, the drawback of the markerless motion capture approach is that the phenomenon of occlusion of motion data occurs in real-time human simulation. In this study, we propose a systematic method of discriminating missing or inaccurate motion data due to motion occlusion and interpolating a sequence of motion frames captured by a markerless depth camera.

• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.434-447
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• 2016

The aim of this paper is the study of instability state of boiling water reactors with a method based in largest Lyapunov exponents (LLEs). Detecting the presence of chaos in a dynamical system is an important problem that is solved by measuring the LLE. Lyapunov exponents quantify the exponential divergence of initially close state-space trajectories and estimate the amount of chaos in a system. This method was applied to a set of signals from several nuclear power plant (NPP) reactors under commercial operating conditions that experienced instabilities events, apparently each of a different nature. Laguna Verde and Forsmark NPPs with in-phase instabilities, and Cofrentes NPP with out-of-phases instability. This study presents the results of intrinsic instability in the boiling water reactors of three NPPs. In the analyzed cases the limit cycle was not reached, which implies that the point of equilibrium exerts influence and attraction on system evolution.

• Journal of Genetic Medicine
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• v.3 no.1
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• pp.15-19
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• 1999

We have investigated the genetic variation in the human apo B mRNA editing protein (apobec-1) gene. Exon 3 of the apobec-1 gene was amplified by polymerase chain reaction. After detection of an additional band by single strand conformational polymorphism (SSCP) analysis, sequencing of the SSCP-shift sample revealed a single-base mutation. The mutation was a CGG transversion at codon 80 resulting in a lleRMet substitution. This substitution was confirmed by restriction fragment length polymorphism analysis since a Pvull site is abolished by the substitution. Population and family studies confirmed that the inheritance of the genotypes for apobec-1 gene polymorphism is controlled by two codominant alleles (P1 and P2). A significant difference in plasma triglyceride was detected among the different apobec-1 genotypes in the CAD patients (P<0.05). Our study could provide the basis for elucidating the interaction between genetic variation of the apobec-1 gene and disorders related to lipid metabolism.

• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.617-618
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• 1998

A simple and reproducible pretreatment method was developed for the determination of dioxins in milk sample. Liquid-liquid extraction (LLE) was used for the initial extraction of the analyte from milk. For the elimination of interferences coextracted from milk, acid treatment followed by multilayer silica gel, and then alumina column clean-up were performed. The clean extract could be obtained without carbon column or high performance liquid chromatographic (HPLC) clean-up procedure. Polychlorinated biphenyles (PCBs) and dioxins were separated on neutral alumina activated at 180 ℃ for 12 hours. The final extract was analyzed by HPLC and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The recovery of dioxins spiked in milk at 75-300 ppt level was 83.3-98.9% and their relative standard deviation was 4.1-14%.