• 제목/요약/키워드: Diacetate

검색결과 233건 처리시간 0.02초

현탁액중 수크랄페이트, 노이시린, 히드로탈사이트에 의한 방부제의 흡착 (Adsorption of Preservatives by Sucralfate, Neusilin and Hydrotalcite in Suspension)

  • 이기준;박은석;정병기;지상철
    • Journal of Pharmaceutical Investigation
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    • 제25권4호
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    • pp.331-338
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    • 1995
  • In order to screen appropriate preservatives for the suspension containing sucralfate, neusilin and hydrotalcite, the patterns and mechanism of the adsorption and desorption of several preservatives on these antacids were studied. The employed preservatives were parabens(methyl, propyl, butyl), chlorhexidine diacetate and sorbic acid. While none of parabens were adsorbed on three antacids, chlorhexidine diacetate was strongly adsorbed on all the antacids employed, especially on hydrotalcite. Sorbic acid was not adsorbed on neusilin and hydrotalcite, however, 65% of sorbic acid was adsorbed on sucralfate. The adsorption of chlorhexidine diacetate on neusilin and hydrotalcite was partly physical and partly chemical, while its adsorption on sucralfate was almost chemical. Sorbic acid was completely deserted from sucralfate. In all cases, the adsorption isotherms were fitted well to both Freundlich equation and Langmuir equation. Based on these results, parabens and sorbic acid were the preservatives of choice for the suspension containing sucralfate, neusilin and hydrotalcite.

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아세테이트 섬유의 염색성 개선에 관한 연구 (A Study on Improving Dyeing Property of Diacetate)

  • 박준호
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2012년도 제46차 학술발표회
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    • pp.84-84
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    • 2012
  • 중동권 국가에서 판매되고 있는 차도르용 고가원단으로 Polyester/Acetate 교직물 제품이 있는데 이중에서 특히 Polyester/Diacetate 교직물은 더 높은 가격에 판매되고 있으며 현재 일본에서 거의 독점하고 있는 시장이다. 아세테이트 섬유는 열에 대하여 약하기 때문에 고온에서 염색을 하지 못하고 $80^{\circ}C$에서 염색하고 있으며, 염료도 소수성 염료인 분산염료를 사용하고 있다. 이러한 조건에서 섬유가 충분히 팽윤되지 못하여 염색이 잘 되지 않으며 잔액이 많이 남는 문제가 있다. 또한 염색에 사용하는 계면활성제 계통의 분산제를 사용할 경우 염료와 친화성이 크기 때문에 염료와 결합하여 염색을 저해하는 문제가 있다. 이러한 문제를 해결하기 위하여 계면활성제 계통의 분산제를 사용하는 대신 친수성 글리콜계 용제를 사용하여 염료의 가용화에 의해 단분자 상태로 만들어 소수성 섬유속으로 염료가 충분히 침투할 수 있는지 확인하였다.

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Synthesis of Triazoloquinoxalines as Antitubercular Agents

  • Sekhar, Kondapalli Venkata Gowri Chandra;Rao, Vajja Sambasiva;Kumar, Dalip
    • Bulletin of the Korean Chemical Society
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    • 제32권8호
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    • pp.2657-2660
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    • 2011
  • 1,2,4-Triazoles and quinoxalines were found to display various pharmacological activities. Hence a series of 1-aryl-4-methyl-1,2,4-triazolo[4,3-a]quinoxalines were synthesized. Due to various advantages of organic reactions under solvent-free conditions these compounds were developed using iodobenzene diacetate under solvent-free conditions. The synthesized compounds were characterized by elemental microanalysis, infrared spectroscopy, $^1H$ NMR, $^{13}C$ NMR and HRMS. All the synthesized compounds were investigated for their antitubercular activity and 5g was found to the most active compound.

PECVD로 제조한 $SnO_2$ 박막의 구조적 특성 (Structural Characteristics of $SnO_2$ Thin Films prepared by PECVD)

  • 이정훈;장건익;손상희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.250-251
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    • 2005
  • Tin dioxide (SnO$_2$) thin films have been prepared on Si wafer (100) by Plasma Enhanced Chemical Vapor Deposition (PECVD). SnO$_2$ thin films were prepared from mixtures of dibutyltin diacetate as a precursor, oxygen as an oxidant at 275, 325, 375, 425$^{\circ}C$, respectively. The microstructure of deposited films was characterized by X-ray diffraction and field emission scanning electron microscopy. Structural characteristics of prepared SnO$_2$ thin films were investigated with different substrate temperature. The deposition rate was linearly increased with substrate temperature. Surface morphology and uniformity of prepared thin film was excellent at 375$^{\circ}C$ and grain size was averagely 25nm.

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Microbial Transformation of Two Prenylated Naringenins

  • Han, Fubo;Lee, Ik-Soo
    • Natural Product Sciences
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    • 제23권4호
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    • pp.306-309
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    • 2017
  • Microbial transformation of $({\pm})$-6-(1,1-dimethylallyl)naringenin (6-DMAN, 1) and $({\pm})$-5-(O-prenyl) naringenin-4',7-diacetate (5-O-PN, 2) was performed by using fungi. Scale-up fermentation studies with Mucor hiemalis, Cunninghamella elegans var. elegans, and Penicillium chrysogenum led to the isolation of five microbial metabolites. Chemical structures of the metabolites were determined by spectral analyses as $({\pm})$-8-prenylnaringenin (3), (2S)-5,4'-dihydroxy-7,8-[(R)-2-(1-hydroxy-1-methylethyl)-2,3-dihydrofurano]flavanone (4), $({\pm})$-5-(O-prenyl)naringenin-4'-acetate (5), $({\pm})$-naringenin-4'-acetate (6), and $({\pm})$-naringenin (7), of which 5 was identified as a new compound.

Studies on the constituents of philippine piper betle leaves

  • Rimando, Agnes-M.;Han, Byung-Hoon;Park, Jeong-Hii;Magdalena-C. Cantoria
    • Archives of Pharmacal Research
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    • 제9권2호
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    • pp.93-97
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    • 1986
  • Fourteen volatile components including eight allypyrocatechol analogs were isolated and identified from the essential oil and ether soluble fraction of Philippine Piper bettle leaves (Piperaceae). The major constituents of Philippine Piper betle oil were chavibetol and chavibetol acetate. Capilary GC analysis of the oil showed chavibetol (53.1%), chavibetol acetate (15.5%), caryophyllene (3.79%), allypyrocatechol diacetate (0.71%), campene (0.48), chavibetol methylether (=methyl eugenol, 0.48%), eugenol (0/32%), $\alpha$-pinene(0.21%), $\beta$-pinene(0.21%), $\alpha$-limonene(0.14%), safrole (0.11%), 1.8-cineol(0.04%), and allylpyrocatechol monoacetate. The major component of the ether soluble fraction was allylpyrocatechol (2.38% of the leaves).

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Effects of sodium diacetate on the fermentation profile, chemical composition and aerobic stability of alfalfa silage

  • Yuan, XianJun;Wen, AiYou;Desta, Seare T.;Wang, Jian;Shao, Tao
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권6호
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    • pp.804-810
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    • 2017
  • Objective: The objective of this study was to evaluate the effect of sodium diacetate (SDA) on fermentation profile, chemical composition and aerobic stability of alfalfa (Medicago sativa L.) silage. Methods: Fresh alfalfa was ensiled with various concentrations of SDA (0, 3, 5, 7, and 9 g/kg of fresh forage). After 60 days of the ensiling, the samples were collected to examine the fermentative quality, chemical composition and aerobic stability. Results: The application of SDA significantly (p<0.05) decreased silage pH with the lowest value in silage with 7 g/kg of SDA. The proliferations of enterobacteria, yeasts, molds and clostridia were inhibited by SDA, resulted in lower ethanol, propionic and butyric acid concentrations and dry matter loss in SDA treated silages than control. The increasing SDA linearly decreased free amino acid N (p<0.001), ammonia N (p = 0.018) and non-protein N (p<0.001), while linearly increased water soluble carbohydrate (p<0.001) and peptide N (p<0.001). It is speculated that SDA accelerated the shift from homofermentative to heterofermentative lactic acid bacteria during the silage fermentation, indicated by lower lactic acid production in SDA-9 than SDA-7 silages after 60 days of ensiling. Alfalfa silages treated with SDA at 7 g/kg had highest Flieg's point and remained stable more than 9 d during aerobic exposure under humid and hot conditions in southern China. Conclusion: SDA may be used as an additive for alfalfa silages at a level of 7 g/kg.