• Title/Summary/Keyword: Chemical substance

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폐기물 매립지 침출수와 침출수 내의 휴믹물질이 GCL의 투수계수에 미치는 영향

  • 한영수;이재영
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.09a
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    • pp.208-211
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    • 2001
  • Geosynthetic Clay Liners (GCLs) have been used for the applications of the hydraulic containment system in landfill due to inexpensive costs, simple workability and distinguished ability as a barrier material. However, bentonite of GCLs is easy to be damaged by the chemical solutions. Thus, there is a need to evaluate the potential susceptibility of GCLs causing Increase the hydraulic conductivity when GCLs are exposed to raw leachate and dissolved humic substances from landfill leachate. The hydraulic conductivity tests were performed with flexible-wall permeameter (the falling -headwater/rising -tailwater procedure) in order to verify the potential susceptibility of GCLs. The values of the hydraulic conductivity conducted with raw leachate as a permeant liquid increased considerably; however, The change of the hydraulic conductivity in the case of humic and fulvic acid were not worthy of notice. As the results of swelling tests of bentonite, however, humic substances can affect badly on the dispersion behavior of bentonite. These results indicate that humic substances dissolved in leachate could reduce the hydraulic conductivity of GCLs in landfill.

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A Study on Concentration of Volatile Organic Compounds in the Apartment House (실내공기중의 휘발성유기화합물 농도변화에 관한 연구)

  • Lee, Yun-Gyu
    • KIEAE Journal
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    • v.4 no.3
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    • pp.129-136
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    • 2004
  • Recently, indoor air pollution has been seriously apprehended, and became a striking issue, due to the airtightness of buildings or the misuse of building materials. Especially, SHS(Sick House Syndrome) and MCS(Multi Chemical Sensitivity) which can have bad influences on the resident in an existing apartment house as well as newly constructed apartment house start to attract public attention. The emission rates of VOCs is sensitively affected by the indoor/outdoor condition, construction materials, construction method, and character of ventilation facilities. Therefore, in this study, by measuring the indoor air pollution substance of the existing apartment house, the problem over this tends to be grasped and it is going to secure an improvement methods.

The Clinical Study of Ketamine HC1 on Oral Surgery (구강외과 영역에 있어서 Ketamine HC1의 임상적 고찰)

  • Cho, Byoung-Uk
    • The Journal of the Korean dental association
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    • v.11 no.1
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    • pp.45-52
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    • 1973
  • Ketamine HC1(Phencyclidine derivative) is a white, crystalline substance with melting point 259℃. It is soluble in water to a 20% clear, colorless solution. a 10% aqueous solution has a pH 3.5. The chemical structure is 2-(O-chlorophenyl)-2-(methylamino) cyclohexanone hydrochloride. It is a rapid acting, nonhypnotic, nonbarbiturate drug with a wide safety margin. The author used the anesthetic ketamine hydrochloride for oral surgery procedure in 16 patients(2 to 33 years). Anesthesia was achieved with a single intramuscular injection by introduction of manufacture. Result obtained as follows : 1. It was easily administered. 2. Onset time was rapid and duration was short. 3. The mild cardiac stimulation resulted in moderate increase in the blood pressure and pulse. 4. There was no significant respiratory depression. 5. The airway can be maintained without artificial support or endotracheal intubation. 6. All protective reflex maintained, which was important in oral surgery. 7. The best results were achieved in pediatric patients than adults.

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A Case of Viral Encephalitis (바이러스성 뇌수막염(Viral Encephalitis) 후유기(後遺期) 환아(患兒) 1례(例)에 대한 증례(症例))

  • Kim, Ki-Hoon;Shin, Dong-Gil;Kim, Deog-Kon
    • The Journal of Pediatrics of Korean Medicine
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    • v.16 no.1
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    • pp.9-19
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    • 2002
  • Viral Encephalitis are a serious meningeal infection occurred by various chemical substance. Chief symptoms are headache. hyperesthesia in child and fretting. irritation in infant. Adolescence complain of a retrobulbar pain, fever, vomiturition, photophobia. Fever can cause choreic movement, mental disorder and seizure. Most of patients have complete recovery, but if there are brain lesions, it is bad prognosis. Occasionally patients complain of continuous headache, mental disorder, ataxia and marasmus. We report on a 4-year-old male patient with viral encephalitis. It has been 40 days since disease. He had disorientation mentality, dysphagia and fever.

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Studies of Chemical Constituents of the Genus Thalictrum in Korea (I) -Alkaloids from the Root of Thalictrum uchiyamai Nakai- (한국특산 Thalictrum속 식물의 성분 연구 (I) -자주꿩의다리 뿌리의 성분-)

  • Lee, Ihn-Rhan;Lee, Myung-Mi
    • Korean Journal of Pharmacognosy
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    • v.13 no.3
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    • pp.132-135
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    • 1982
  • Three phenolic alkaloid compounds (A,B,C) were isolated from the roots of Thalictrum uchiyamai Nakai (Ranunculaceae). Compound A, a colorless crystalline substance $mp168^{\circ}$, $C_{11}H_{15}NO_2$ was identified to be corypalline (6-methoxy-7-hydroxy-N-methyl-1, 2, 3, 4-tetrahydroisoquinoline) which has been reported by Wu from Thalictrum rugosum. Compound B, $mp166^{\circ}$ and Compound C, $mp164^{\circ}$ were shown aromatic rings by UV, IR spectra and chiral center by CD.

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Physico-chemical Characteristics and Antiviral Activity of ASA, an Antibiotic Produced by Actinomycetes B25 (방선균 B25 균주가 생산하는 항생물질 ASA의 물리.화학적 특성 및 항바이러스 활성)

  • 여운형;김영호;박은경;김상석
    • Korean Journal Plant Pathology
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    • v.13 no.1
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    • pp.63-68
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    • 1997
  • In the screening of antiviral materials produced by actinomycetes, an isolate named B25 was fond to produce an antibiotic substance ASA, which showed a strong inhibitory activity against tobacco mosaic virus (TMV) infection. ASA was purified from culture broth of B25 by silica gel column chromatography, preparative TLC, and reversed phase HPLC. Also MS, IR, UV spectrum, and melting point of ASA were determined and analysed. ASA was white powder soluble in dimethyl sulfoxide, chloroform, and ethyl acetate, having absorption peaks at 223 and 328 nm in UV-VIS spectrum, and had a molecular weight of 548. ASA showed strong inhibitory effect on TMV infection when it was applied as a mixture of TMV to the upper surface of leaves of a local lesion host (Nicotiana tabacum c. Xanthi-nc). It also showed antimicrobial effect against yeast and some phytopathogenic fungi.

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Review on Cellulose acetate as a Packaging Materials (셀룰로오스 아세테이트 포장소재의 이용 및 고찰)

  • Lee, Ji-Yoon;Jang, Si-Hun;Park, Su-Il
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.16 no.1
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    • pp.19-25
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    • 2010
  • It is becoming increasingly important to utilize alternative raw materials for plastic industries other than petrochemical-based plastics. Cellulose derivatives were the bases of the original synthetic plastics. Cellulose and its derivatives, especially the widely used cellulose acetate (CA), constitute one of the main classes of raw materials for production on artificial fibers, films, plastics etc. CA is one of the well known polymers produced from naturally available plant substance. Many researches have focused on the isolation of cellulose from the plant cells to use them as cellulose derivatives and composite materials. Chemical and mechanical treatments provide changes on the molecular structures influencing the fundamental properties of these naturally abundant polymer. The aim of this review article is to review biodegradation, synthesis, formation, and utilization of cellulose esters, especially di-acetate, used in packaging related researches.

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Enterococcus faecium 19-46-4에 의한 Cholic Acid의 생산

  • Chung, Eun-Young;Kim, Myung-Soo;Lee, Chul-Hoon;Kim, Byung-Hong
    • Microbiology and Biotechnology Letters
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    • v.24 no.5
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    • pp.540-545
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    • 1996
  • A facultative anaerobe Enterococcus faecium 19-46-4 was used to study the production of an antimicrobial substance in anaerobic conditions. Major part of the antibiotic activity was found in the culture filtrate of the bacterium. The active compound was extracted by an equal volume of iso-butanol and concentrated in vacuo (at 50$\circ$C) before purification by C-18 liguid column chromatography and HPLC. A chromatographically pure compound was obtained by two passages of HPLC columns, The compound appeared as a pale-yellow powder. The yield was about 2.5 mg 1$^{-1}$ culture filtrate. The compound was named as KIST 194. KIST 194 were identified as cholic acid (3$\alpha$, 7$\alpha$, 12$\alpha$-trihydroxy-5$\beta$-cholan 24-oic acid) based on its physico-chemical properties determined by UV, IR, $^{1}H-NMR, $^{13}$C-NMR, El-MS and LC-MS.

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A Study on Survey of Plating Company for the Chemical Substance Management Act (화학물질관리법 대응을 위한 도금업체 실태 조사 및 개선방안 모색에 관한 연구)

  • Lee, Jun-Gyun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.74-74
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    • 2017
  • 화학물질관리법 시행에 따른 도금기업의 준비 현황 및 실태를 조사하기 위하여 중간보고서에서는 대부분의 업체에서 가장 부담스럽다고 느낀 '유해화학물질 취급시설 배치 설치 관리 기준' 중 실질적으로 가장 어려움을 호소하는 내용부터 설문조사를 실시하여 정리하였고, 최종보고서에서는 한국경영자총협회에서 제안한 "화관법 개선 산업계 의견"을 참고하여 도금업체의 현장과 관련된 부분을 선정하여 실태조사를 실시하였다. 장외영향평가서 및 위해관리계획서 부문의 경우 도금공장의 시설 결함 및 노후화로 인하여 화학사고가 발생할 가능성이 있더라도 대부분의 현장이 화관법 기준을 충족하기 이전에 시설 허가를 받을 때 건축법이나 소방법 등 여러 규제사항을 통과하여 인 허가를 받은 사업장이고 또한 정기검사를 실시함으로써 안전에 대해서는 일차적으로 보장을 받은 상태라고 볼 수 있다. 실제로 설문조사에서 화학사고를 경험과 관련하여 94% 이상이 "없다"라고 응답하였으므로 약품에 의한 화학사고의 개연성은 거의 없는 것으로 나타났다.

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Effect of Solvent Extraction on the Anti-complementary Activities of Green and Ripe Cucurbita moschata Duch

  • Yang, Jin-Ok;Kim, Chang-Jin;Song, Kyung-Bin
    • Preventive Nutrition and Food Science
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    • v.6 no.2
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    • pp.133-135
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    • 2001
  • The edible part of cucurbita moschata Duch, which is commonly used as a Korean traditional medicine as well as a popular food source, was studied to isolate anti-complementary substance. Extracts of Cucurbita moschata Duch showed significant anti-complementary activities on the classical pathway of the complement system. Especially, the ripe Cucurbita moschata Duch had more activity than that of the complement system. Especially, the ripe Cucurbita moschata Duch had more activity than that of the green one in terms of the overall anti-complementary activity. Among the extracts of various organic solvents of the ripe Cucurbita moschata Duch, chloroform and ethyl-acetate extracts, which are non-polar solvent extracts, showed the strongest activities. These results suggest that the major difference in the solvent extraction for the anti-complementary substances depends on the change in the chemical composition such as the fatty acid with the degree of ripening.

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