• Journal of Microbiology
• /
• 제43권5호
• /
• pp.424-429
• /
• 2005

In previous studies, it has been reported that both S. enteritidis, the most common serotype, and S. enteritidis Phage Type 4 (SEPT 4) isolates were identified as the most prevalent PT in domestic poultry and also in humans in Korea until 2002. The aim of this study was to analyze the genetic diversity and epidemiological properties of both PT isolates, and also to trace the source of SEPT 4 isolates from domestic poultry and humans by Pulsed-field gel electrophoresis (PFGE). In order to understand the molecular epidemiologic properties of SEPT 4 isolates, which have very similar phenotypic properties to our preliminary investigations (serotyping, phage typing, large plasmids and antibiograms), PFGE analysis with XbaI enzyme was performed on the representative SEPT 4 isolates. Thirty-six SEPT 4 isolates were analyzed and differentiated with 10 pulsed-field profiles (PFP) expressing very high discriminative ability (SID: 0.921). In PFP, SEPT 4 isolates from human patients showed a perfect genetic match with those from broiler chickens and meats. Therefore, this study was able to successfully trace the major source of SEPT 4 isolates and also to determine the usefulness of the PFGE method for genetic analysis of epidemic strains.

• 한국표면공학회지
• /
• 제36권6호
• /
• pp.444-454
• /
• 2003

The effect of trace metallic additives of Al-Fe-X on microstructure, glossiness and hardness of Zn electrodeposits was investigated by using sulfate bath. The preferred orientation of Zn deposits with Al-Fe additives was (10 l)(l:3,4,2), while that of Zn deposits with Al-Fe-X(Ni,Co) additives was either (002) or (002)＋(103)ㆍ(104) mixed orientation. The preferred orientation of Zn deposits with Al-Fe-Cr additives changed from (002)+(10 l) to (10 l) orientation with increasing amount of Al additive. The surface morphology of the Zn deposits was closely related to the preferred orientation of the deposits. The glossiness of Zn deposits with Al-Fe additives increased in comparison with that of pure Zn deposit. That of the Zn deposits with Al-Fe-X additives was related to the morphology of the deposits and changed according to type of additives. The hardness of Zn deposits with Al-Fe-X(Ni,Co,Cr) additives was noticeably higher than that of Zn deposits with Al-Fe additives.

• Bulletin of the Korean Chemical Society
• /
• 제22권1호
• /
• pp.19-24
• /
• 2001

A solvent sublation has been studied for the determination of trace Au(III), Pt(IV) and Pd(II) in waste water with their complexes of 2-mercaptobenzothiazole (MBT). Experimental conditions such as the concentration of HCl, the amount of MBT as a ligand, the type and amount of surfactants, bubbling rate and time, and the type of organic solvent were optimized for the solvent sublation, i.e., 25.0 mL of 2.0 M HCl solution and 30mL of 0.4%(w/v) MBT ethanolic solution were added to a 1.0 L sample to form stable complexes. The addition of 4.0 mL of 1 ${\times}$$10^{-3}$ M CTAB (cetyltrimehtylammonium bromide) solution was needed for the effective flotation accomplished by bubbling nitrogen gas at the rate of 40.0 mL/min for 35 minutes. As a solvent, 20.0 mL of MIBK (methylisobuthylketone) was used to extract the floated complexes. The procedure was applied to three kinds of waste waters. Au(III) was determined as 0.68 ng/mL and 0.98 ng/mL respectively for final washed water of two plating industries in Banwol. Pd(II) and Pt(IV) were not detected in any of the three samples. The recovery, which was obtained with analyte-spiked samples, were 95-120%.

• Nuclear Engineering and Technology
• /
• 제51권6호
• /
• pp.1532-1539
• /
• 2019

This paper analyzes a new method for reducing boiling water reactor fuel temperature during a Loss of Coolant Accident (LOCA). The method uses a device called Reverse Flow Restriction Device (RFRD) at the inlet of fuel bundles in the core to prevent coolant loss from the bundle inlet due to the reverse flow after a large break in the recirculation loop. The device allows for flow in the forward direction which occurs during normal operation, while after the break, the RFRD device changes its status to prevent reverse flow. In this paper, a detailed simulation of LOCA has been carried out using the U.S. NRC's TRACE code to investigate the effect of RFRD on the flow rate as well as peak clad temperature of BWR fuel bundles during three different LOCA scenarios: small break LOCA (25% LOCA), large break LOCA (100% LOCA), and double-ended guillotine break (200% LOCA). The results demonstrated that the device could substantially block flow reversal in fuel bundles during LOCA, allowing for coolant to remain in the core during the coolant blowdown phase. The device can retain additional cooling water after activating the emergency systems, which maintains the peak clad temperature at lower levels. Moreover, the RFRD achieved the reflood phase (when the saturation temperature of the clad is restored) earlier than without the RFRD.

• 분석과학
• /
• 제36권5호
• /
• pp.205-215
• /
• 2023

In the present study, an analytical method was proposed for detecting trifluralin in aquatic products at trace concentrations. The method employed QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) and gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) as the sample preparation and measurement, respectively. The effect of the aqueous phase volume used in the QuEChERS was demonstrated, and the ratio of 10:10 (mL) between water and acetonitrile phase was used for 5 g of sample. Besides, dSPE using C18 and primary-secondary amine (PSA) was applied to remove the potential interferences from the food matrices, indicating no remarkable analyte loss. The linear range was built up from 0.50 ㎍ L^-1 to 3.0 ㎍ L^-1 (R² = 0.9993). Other criteria, i.e., repeatability (RSD_r = 0.86-1.96 %), reproducibility (RSD_R = 1.09-2.01 %), and recovery (over 90 %), were in accordance with Appendix F of AOAC (2016) for method performance. Although no trifluralin was detected for the commercial samples (fish, shrimp, and breaded shrimp), the spiked samples performed favorable recoveries and precision.

• 해양환경안전학회지
• /
• 제19권4호
• /
• pp.303-308
• /
• 2013

2011년 7월부터 2012년 2월에 걸쳐 광양만, 목포내만, 신안 비금도 주변해역의 저층 퇴적물의 COD와 AVS를 조사하여 해저 퇴적물의 오염도를 평가하였다. 아울러 퇴적물 중의 Cu, Cd, Pb, Zn의 함량을 조사하여 국내기준치와 외국의 기준치와 비교 평가하였고, 농집지수를 구하여 중금속의 축척과 인위적인 영향을 추정하였다. 그 결과, COD와 AVS를 이용한 해역의 오염도는 신안 비금해역과 광양만은 I등급, 목포내만은 III등급으로 평가되었다. 중금속의 조사 결과에서는 목포내만과 광양만에서는 중간오염 상태를 보였고, 신안 비금해역은 오염되지 않은 상태를 보였다. Igeo 결과에서 2 이상으로 나타난 곳은 목포내만과 광양만에서 Cu와 Cd이 오염된 상태를 보였다. 이와 같은 결과로부터 인위적인 오염원이 없는 해역의 경우에는 일반항목으로 퇴적물의 오염도를 평가할 수 있겠지만 산업시설이 밀집된 인위적인 영향이 큰 해역의 경우에는 퇴적물의 일반항목외 중금속을 이용한 해저 퇴적물의 오염도의 평가가 더욱 정확할 것으로 판단되었다.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 춘계학술대회
• /
• pp.88-91
• /
• 1997

One of the most significant feature of diagnostic ultrasonic instrument is to display information on the soft tissues in the body in real time. In this paper we carried out basic study on the digital moving image processing for tracing the movement of heart valves in echocardiograms. Digital moving image file was made from analog echocardiograms and it was remade as 256 gray-level images on each frame. The ROI(Region of interest) was placed on a heart valve region to process images efficiently. Images were processed by the use of image enhancement filters and morphology filters. The result shows that the processed images were more enhanced than original images. When a moving image is reconstructed by using these enhanced images, we can trace the movement of heart valves more easily. In this study we proposed the availability of the moving image reconstruction using enhancement images.

• KSBB Journal
• /
• 제24권1호
• /
• pp.59-64
• /
• 2009

The callus formation from inferior leaf of Aloe saponaria was induced in M & S medium supplemented with 10-30 ${\mu}M$ NAA (${\alpha}$-naphthalene acetic acid) and 3-7 ${\mu}M$ kinetin under incubation in the dark at $25^{\circ}C$ for 6 weeks. The hot water extract ($100^{\circ}C$, 24 hrs) from cultured callus was obtained and the components analysis for the extract were examined to determine the callus can synthesized the bioactive component such as Aloe polysaccharide. The freeze dried extract contained the sugar of 53.2%, protein of 7.3%, ash of 18.5% and water of 21% (w/w). Two fractions (Fr-I and Fr-II) were obtained by Sepharose CL-4B gel permeation chromatography and Fr-I, major fraction was further purified with dialysis. From sugar analysis by TLC and GC, the purified Fr-I fraction consisted of glucose (77.6%), galactose (17.7%), mannose (4.7%, w/w) and uronic acid (trace). The molecular weight of purified Fr-I fraction determined by GPC was about 110 kDa.

• Bulletin of the Korean Chemical Society
• /
• 제24권7호
• /
• pp.948-952
• /
• 2003

New approach for the determination of Ag(I) ion was performed by using a carbon paste electrode (CPE) containing N,N'-Diphenyl oxamide (DPO) with anodic stripping voltammetry. The CMEs have been prepared by making carbon paste mixtures containing an appropriate amount of DPO salt coated onto graphite particles to analyze trace metal ions via complexation followed by stripping voltammetry. Various experimental parameters affecting the response, such as pH, deposition time, temperature, and electrode composition, were carefully optimized. Using differential pulse anodic stripping voltammetry, the logarithmic linear response range for the Ag(I) ion was 1.0 × $10^{-7}$ - 5.0 × $10^{-9}$ M at the deposition time of 10 min, with the detection limit was 7.0 × $10^{-10}$ M. The detection limit adopted from anodic stripping differential pulse voltammetry was 7.0 × $10^{-10}$ M for silver and the relative standard deviation was ± 3.2% at a 5.0 × $10^{-8}$ M of Ag(I) ion (n = 7). The proposed electrode shows a very good selectivity for Ag(I) in a standard solution containing several metals at optimized conditions.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
• /
• pp.352-357
• /
• 1998

Conventional marketing research generally focuses on a single layer's benefit. A notable example is the consumer layer providing managers with partial market information to evaluate relevant strategies. As generally known, marketing management encounters complex supply and demand behaviors, thereby necessitation that a successful marketing strategy adopt multi-layer considerations, such as the consumer layer, channel-retailer layer, and marketing planner layer. In light of above situation, this study applies fuzzy theory and the analytic hierarchy process(AHP) technique to analyze the performances of marketing strategies under multi-layer benefits, In addition, conventional marketing research has difficulty in efficiently allocating the limited budget so that each desired criterion can be significantly enhanced by a group of events. Therefore, a weighting structure among the goal, layers, criteria, and strategies(i.e. a group of events) is also developed herein to trace the influential process and assist marketing managers in efficiently allocating resources(i.e.budget).