• Fibers and Polymers
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• 제3권2호
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• pp.68-73
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• 2002

In this study, a new type of Aliquat 336/PVC membrane has been made for extraction experiments. This new membrane is capable of holding more Aliquat 336 than previously developed extraction membranes, hence overcoming a major problem that has confronted many researchers for a long time. The new membrane has been used try investigate the rate of extraction fur the Cd(II) ion in 2.0 M HCI solution and the effect of membrane thickness on the rate of extraction. The experimental results have shown this new membrane has a promising future in relevant industrial applications. A new method is also used in this study to qualitatively identify the oily substance on the surface of membrane after the extraction experiment was completed. This oily substance has been found to be Aliquat 336.

• 대한화학회지
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• 제5권1호
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• pp.15-17
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• 1961

A ninhydrin positive substance(formed during germination of Mung Bean) which on a 2-dimensional chromatography(BuOH-HAc, and$ PhOH-NH_2$ gave a spot above glutamic acid was isolated by cutting out the appropriate spot on the paper and extracting the paper with water. Hydrolysis of this substance with $2N H_2SO_4\;or\;3N\;HCl\;at\;120^{\circ}C$ for 15 hours gave the spot of mainly glutamic acid, alanine and very faint of glycine and cysteine on a paper chromatography. It is suggested that the reaction of ${\gamma}$-glutamyl-cysteinecyl-glycine + L-alanine in the presence of ${\gamma}$-glutamyle transferase ${\rightarrow}$ ${\gamma}$-glutamyl-alanine + cysteinyl-glycine, takes place in germinated Mung Bean.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.531-538
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• 2013

A mass balance method established in this laboratory was applied to determine the purity of an endosulfan-II pure substance. Gas chromatography-flame ionization detector (GC-FID) was used to measure organic impurities. Total of 10 structurally related organic impurities were detected by GC-FID in the material. Water content was determined to be 0.187% by Karl-Fischer (K-F) coulometry with an oven-drying method. Non-volatile residual impurities was not detected by Thermal gravimetric analysis (TGA) within the detection limit of 0.04% (0.7 ${\mu}g$ in absolute amount). Residual solvents within the substance were determined to be 0.007% in the Endosulfan-II pure substance by running GC-FID after dissolving it with two solvents. The purity of the endosulfan-II was finally assigned to be ($99.17{\pm}0.14$)%. Details of the mass balance method including interpretation and evaluating uncertainties of results from each individual methods and the finally assayed purity were also described.

• 환경위생공학
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• 제10권1호
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• pp.132-141
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• 1995

The objectives of this study was to find the effect of zinc salt treated with coconut activated carbon and the effect of humic substance. The bottle- Point technique was used in determining the Freundlich isotherm equation. The adsorptive capacity of granular activated carbon was reduced when humic substance are present. Coconut activated carbon was coated with 0.0001 N zinc chloride decreased the BET surface area but increased the adsorptive capacity more than coconut activated carbon not coated with zinc chloride. The adsorptive capacity of TCE in coconut activated carbon coated with higher concentration of zinc chloride was reduced but increased in the solution containing humic substance when the coconut activated carbon was coated with 0.01 N- zinc chloride. The zinc salt coated with coconut activated carbon did not Increase the adsorptive velocity of coconut activated carbon.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1217-1220
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• 2007

The saprophytic fungus Ulocladium atrum Preuss is a promising biological control agent for Botrytis cinerea in greenhouse- and field-grown crops. However, despite its known potent antifungal activity, no antifungal substance has yet been reported. In an effort to characterize the antifungal substance from U. atrum, we isolated an antibiotic peptide. Based on extensive spectroscopic analyses, its structure was established as a cyclopeptolide with a high portion of N-methylated amino acids, and its $^1H$ and $^{13}C$ chemical shifts were completely assigned based on extensive 1D and 2D NMR experiments. Compound 1 exhibited potent antifungal activity against the plant pathogenic fungus Botrytis cinerea and moderate activity against Alternaria alternate and Magnaporthe grisea.

• 대한화학회지
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• 제56권6호
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• pp.739-750
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• 2012

이 연구에서는 중학교 '과학2' 교과서에 서술되어 있는 '이온 결합 화합물'과 '분자'에 대한 내용이 요구하는 인지 요구도를 분석하였다. 우리나라는 2007년 개정 교육과정에 의하여 처음으로 '이온 결합 화합물'과 '분자' 내용들을 중학교에서 다루게 되었다. 분석에 활용한 6종 과학 교과서에 서술된 내용이 어떠한 인지 수준을 요구하는 지를 알아내는 분석틀은 영국에서 개발된 Curriculum Analysis Taxonomy의 3종류 분석틀을 사용하였다. 이 3종류 분석틀에 의하여 분석한 '과학2' 교과서에 서술된 내용이 요구하는 인지 수준들은 다음과 같았다. 첫째, '순물질과 혼합물'에 대해서 대부분의 교과서가 대부분 분류 포섭이나 분류 위계를 하고 있어서 후기 구체적 조작 수준이다. 그러나 모든 교과서가 혼합물 속에 들어 있는 각각의 순물질들이 본래의 성질을 잃지 않고 그 성질이 보존된다는 것을 알게 하고 있기 때문에 초기 형식적 조작 수준이다. 둘째, '이온 결합 화합물'과 '분자'에 대해서 교과서 모두 초기 형식적 조작 수준으로 판정되었다. 그 자체의 규칙을 따르는 가상의 계로부터 연역적인 비교를 통하여 실체를 간접적으로 해석할 수 있는 형식적 모델을 사용한다거나 또는 원자가 구조를 가진다는 것을 설명하기 때문에 형식적 조작 수준이다. 셋째, '이온 결합', '이온 결합 화합물', '화학식', '공유 결합', '공유 결합 화합물', '분자식' 등의 용어들을 사용하는 '과학2' 교과서가 많이 있었다. 이러한 용어들은 중학교 '과학3'에서도 그리고 고등학교 '과학'에서도 사용되지 않고 있으며 고등학교 '화학I'과 '화학II'에 가서야 사용되는 용어들이다.

• 대한기관식도과학회지
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• 제2권1호
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• pp.97-102
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• 1996

The larynx has three major functions such as protective reflex, respiration and phonation, and is richly innervated by sensory, sympathetic and parasympathetic nerves. The sensory innervation of the laryngeal mucosa, which is involved in the perception of pain, mechanical and chemical irritation, prtects the airway via various laryngeal reflexes. We studied the distribution of Substance P (SP) and Calcitonin Gene-Related Peptide (CGRP) sensory fibers in the rat's larynx using the immuno-histochemical methods. Many SP and CGRP immunoreactive fibers were found in all regions of the laryngeal mucosa except the vocal cords. SP immunoreactive fibers showed a very similar distribution to the CGRP fibers in the epithelium and submucosa. But SP immunoreactive fibers were sparser than CGRP immunoreactive fibers in distribution density. Both reactive fibers were denser in the supraglottic region than subglottic region. Especially, intraepithelial fibers displayed the densest innervation to the laryngeal surface of the epiglottis. h the subepithelium, SP and CGRP immunoreactive fibers were distributed along the wall of vessels and around the glands. The present results suggest that the regional distribution of SP and CGRP immunoreactivity may be responsible for the protective reflex function of the laryngeal inlet.

• Preventive Nutrition and Food Science
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• 제6권4호
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• pp.230-234
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• 2001

The extract of Ulmus davidiana var. japonica cortex has known as natural anti-inflammatory substance in East Asia. For the identification of antimicrobial substance, it was extracted by using methanol and fractionated by using different organic solvents. The fraction of butanol was represented the highest antimicrobial activities. Therefore, the butanol fraction was purified and identified the chemical structure by $^1$H and $^{13}$ C-NMR spectra, FT-IR and EI/MS spectroscopies. The isolated antimicrobial substance was identified as cis-2-[3,4-dihydroxy phenyl]-3,4-dihydro-2H-1-benzopyran-3,5,7-triol, which has commonly known as (-)epicatechin. Its minimum inhibitory concentrations (MICs) against Staphylococcus aureus and Listeria monocytogenes were shown as 100 $\mu\textrm{g}$/mL, respectively.

• 자원리싸이클링
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• 제20권5호
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• pp.58-63
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• 2011

Fe-EDTA를 함유한 수침목재유물 보존처리 폐수로부터 EDTA를 회수하고 재활용하기 위해 산 조절 침전 석출 기법을 이용하였다. EDTA는 문화재보존처리 분야에서 수침고목재의 흑화현상을 제거하는데 사용되어왔다. 수침목재유물은 오랜 기간 땅속에서 매장되어 토양의 Fe가 목재 내부의 타닌과 결합하여 흑색을 띄게 되며, 목재의 흑색을 제거하기 위해 고농도의 EDTA용액을 사용한다. 목재의 흑색은 Fe-EDTA착물이 형성되어 제거되며, EDTA는 pH 2.68이하에서 Fe와 분리되어 침전된다. 침전획득물과 실제 EDTA를 적외선분광분석기 (FT-IR)와 전계방사형 주사전자현미경(FE-SEM)를 이용하여 비교 분석하였다. 분석결과 pH조작 후의 침전획득물은 나트륨착체나 Fe-EDTA 형태의 착물형성이 아닌 순수한 EDTA로 확인되었다. 본 연구에서는 Fe-EDTA를 함유한 폐수에 HCI을 첨가하여 Fe$^{3+}$를 분리해 내고 강산성에서 EDTA가 석출되는 원리를 이용하여 EDTA의 재활용이 가능하다.

• 약학회지
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• 제33권3호
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• pp.203-205
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• 1989

A method is presented for calculating the $^{13}C$ chemical shifts produced in liquid solution by referenced relative to RF frequency. The method is useful to get the real variations of chemical shifts in magnetic field by eliminating the affects of the variation of a reference substance.