• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.12-21
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• 1987

Residues of some organo-chlorine pesticides on 108 solis collected from 5 sites of Chungnam avea during March 20-April 6, 1986 were investigated. 12 different kinds of Chemical components were detected showing the highest detection frequency with P.P'-DDE(67.6%) and the lowest with Heptachlor(1.8%). 4 different chemicals, ${\alpha}-BHC$, ${\gamma}-chlordane$, P.P'-DDD and P.P'-DDD and P.P'-DDE showed their average contents in the soils of 0.001 ppm and 0.005ppm for ${\beta}-BHC$, respectively. On the other hand, ${\alpha}-BHC$, ${\gamma}-chlordane$, P.P'-DDT. O.P'-DDT and P.P'-DDD showed 0.002ppm for their average contents of residues, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.11
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• pp.952-960
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• 2018

Recently, lots of remote sensing satellite require agility to collect more images within the limited time frame. To satisfy this kind of mission requirement, high torque actuator such as CMG is an essential element. In this study, 5Nm class small CMG developed by KARI is introduced to implement for an agile small satellite design. One of the singularity escape CMG steering law, Designated Direction Escape (DDE) method, which is a sort of modified version of Singular Direction Avoidance (SDA) method is summarized for its application on the numerical simulation of agile attitude control system design result. The performance of DDE method is demonstrated properly by escaping well known elliptic internal singularity successfully. 5Nm class small CMG cluster in a pyramid type as well as a roof type configuration is utilized to perform the numerical simulation and to demonstrate its agility design result for a small satellite. Simulation result shows the properness of 5Nm small CMG to a small agile satellite system. Also, the simulation result provides some valuable information that is important to CMG hardware design and manufacturing.

• Composites Research
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• v.35 no.2
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• pp.53-60
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• 2022

This study uses Diglycidyl ether of terephthalylidene-bis-(4-amino-3-methylphenol) (DGETAM), an amine hardener 4,4'-diaminodiphenylethane (DDE) and cationic catalyst N-benzylpyrazinium hexafluoroantimonate (BPH) to make epoxy film. For analysis, ¹H_NMR and FT-IR were used to verify proper synthesis, and the liquid crystallinity of DGETAM was checked using Differntial Scanning Calorimetry and Polarized Optical Microscopy. Thermal conductivity of the sample was measured using Laser Flash Apparatus. Thermal stability as well as thermal conductivity is important when used as a packaging material. Activated energy is the energy needed to generate a response, which can be used to estimate the energy required to maintain physical properties. It was obtained using the Arrhenius equation based on the data measured by isothermal decomposition using Thermogravimetric Analysis. Measurement of the thermal conductivity of epoxy films showed higher thermal conductivity when DDE was used, and it was found that thermal conductivity had an effect on thermal stability, given that it represented an activation energy similar to a film with BPH upon 5% decomposition.

• Environmental Mutagens and Carcinogens
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• v.22 no.1
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• pp.30-38
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• 2002

In view of the effect of antithrombin III on essential hypertension, we investigated the 5' untranslated exon 1 length (I/D) polymorphism and intron 5'-DdeI RFLP of the human antithrombin III gene in the Korean patients with essential hypertension. There were no significant differences in the allele, genotype and haplotype frequencies of these polymorphisms between normotensive and essential hypertensive subjects. The significant linkage disequilibrium was however, detected between I/D polymorphism and Dde I RFLP. The I/D polymorphism was also significantly associated with BMI, total cholesterol (TC) and HDL- cholesterol levels, while DdeI polymorphism with age and BMI. Therefore, our results suggest that the significant association between the genetic polymorphisms in the antithrombin III gene and variable cardiovascular risk factors may reflect the potential role of human antithrombin III gene in cardiovascular function.

• Journal of Life Science
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• v.19 no.9
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• pp.1328-1332
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• 2009

Anisakidosis is caused by anisakid nematodes (family Anisakidae) larvae which can cause not only direct tissue damage but also a severe allergic response related to excretory-secretion products. Lots of different species of anisakid larvae, including Anisakis simplex, Contracaecum, Goezia, Pseudoterranova, and Hysterothylacium, cause the anisakidosis. But it is difficult to diagnosis the species of larvae since the morphologies of larval anisakid nematodes are almost indistinguishable. In order to diagnosis the differential infections of larval anisakid nematodes, polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) of 18S rDNA - was conducted. Three major species of anisakid larvae including A. simplex, C.ontracaecum spp, and Goezia spp. were collected from mackerel (Scomber japonicus), mullet (Mugil cephalus), founder (Paralichthys olivaceus), eel (Astroconger myriaster) and red sea bream (Pagrus major). PCR amplified 18S rDNA from each species of anisakid larvae was digested with eight restriction enzymes including Taq I, Hinf I, Hha I, Alu I, Dde I, Hae III, Sau96 I, and Sau3A I. The original sizes of PCR amplified 18S rDNA were 2.0Kb in both anisakid larvaes and Goezia. Restrction enzymes including Hinf 1, Alu 1, Hha I, Dde 1 and Hae III cut differently and distinguished the A. simplex and Contracaecum type C'. However, Contracaecum type A showed two different restriction enzyme cutting patterns by Taq 1, Hinf I, Alu 1, and Dde 1. One of the patterns was the same as those of A. simplex, Contracaecum type C' and Goezia and the other was unique. These results suggest that PCR-RFLP pattern by Hinf 1, Alu 1, Hae I, Dde 1 and Hae III can be applied to differential diagnosis of human infection with A. simplex and Contracaecum type C'. Contracaecum type A needs further study of classification by morphological characteristics and genetic analysis.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1999.10a
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• pp.269-270
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• 1999

• Analytical Science and Technology
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• v.9 no.3
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• pp.320-324
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• 1996

The dynamic range of mass selected detector, which is very popular recently because of the simplicity and cheap price, was determined by using priority pollutants. The applied priority pollutants were four pesticides, 4,4'-DDE and 4,4'-DDD, which show the sharp peaks, and ${\alpha}$-endosulfan and ${\beta}$-endosulfan, which show the broad peaks in SIM Chromatogram. The dynamic range of the 4,4'-DDE and the 4,4'-DDD was $0.1{\sim}3000{\mu}g/ml$. The broad peaks of the ${\alpha}$-endosulfan and ${\beta}$-endosulfan resulted in $0.25{\sim}3000{\mu}g/ml$ of dynamic range.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.391-394
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• 2002

This paper introduces that the lathe optimize for main and sub spindle's synchronous in Opening-CNC. In view of optimal design, the mathematical modelling and the frequency domain analysis of spindle's system are performed. For the compensation of synchronous error in compounded manufacture process, the optimization method of motor drive's control parameter and the related parameter is proposed. By the experiment in prototype machines using the server/client program, the validity of the proposed method is verified.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.816-818
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• 1998

In this paper Polyimide(PI) thin film are fabricated by vapor deposition polymerization(VDP) of dry process which are easy to control the film's thickness and hard to pollute due to volatile solvent. The FT-IR spectrum show that PAA thin films fabricated by VDP are changed to PI thin film by thermal curing. From AFM(Atomic Force Microscopy) experimental as the higher curing temperature. the thin film thickness decreases and roughness decresse.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.154-157
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• 1996

The thin films are fabricated by VDPM and its heat resistant characteristics are investigated using Thermogravimetry. About polyimide, there is a wide difference between 5% weight loss temperature of TG curve and 20,000hr. of life time by methode of ASTM D2307. Therefore, TGI can be obtained by thermogravimetric analysis of NEMA std. pub. NOREI-1974. The TGI was got 670, 674 and 585 at 20$^{\circ}C$, 40$^{\circ}C$ and 70$^{\circ}C$, respectively.