• Title/Summary/Keyword: Physiochemical

검색결과 468건 처리시간 0.031초

택사의 항균 및 항진균 작용에 관한 연구 (Antimicrobial and Antifungal Studies on Alismae Rhizoma)

  • 도정애
    • 생약학회지
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    • 제27권4호
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    • pp.378-382
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    • 1996
  • We previously reported the morphological, physiochemical characteristics of Alismae Rhizoma. In this study, we examined the antimicrobial and antifungal activities of 85% ethanol and water extracts of Alismae Rhizoma using disc method. Ethanol extracts of Korean Alismae Rhizoma showed antimicrobial activity on B. subtilis and S. aureus on the concentration dependent manner, whereas, Chinese Alismae Rhizoma revealed antimicrobioal activity on E. coli and N. gonorrhoeae. The water solution(500 mg/ml) of each lyophilized powder of aqueous extracts didn't show any antimicrobial activity on B. subtilis, S. aureus and E. coli, on the contrary, they stimulated cell growth slightly. Ethanol extracts of Korean samples showed antifungal activity on A. niger, but not on C. albicans. Neither A. niger nor C. albicans were affected by Chineses samples.

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Physicochemcal Properties of Jeungpyun, Korean Traditional Fermented Rice Cake Prepared with Brown Rice and Barley Flour

  • Hye Young L. Kim;Mie Ja Park
    • 환경생물
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    • 제21권4호
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    • pp.377-383
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    • 2003
  • The functional Jeungpyuns with dietary fiber containing cereals such as brown rice and barley flour were developed and physiochemical properties were investigated. The water binding capacity had significantly the highest value of 28.4% in raw rice flour, followed by brown rice flour and barley flour. The lowest reducing sugar value was seen in unpolished rice substituted Jeungpyun with value of 5.420 (P<0.05). The amount of reducing sugar decreased slightly after steaming, due to the increased degree of sugar dissociation. The L value of the lightness decreased significantly with the substituted samples (P< 0.05). The barley substituted samples were darker than that of brown rice sample groups with less green and yellow color. Microstructures of starch particles after fermentation showed completely dispersed starch particles with air bubbles and sponge-like structure in all samples after steaming. Thus, functional Jeungpyun replaced with brown rice and barley flour can be successfully formulated and has been influenced by the physicochemical properties.

Temperature on structural steelworks insulated by inorganic intumescent coating

  • Choi, J. Yoon;Choi, Sengkwan
    • Steel and Composite Structures
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    • 제15권1호
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    • pp.1-14
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    • 2013
  • Predicting the fire resistance of structures has been significantly advanced by full scale fire tests in conjunction with improved understanding of compartmental fire. Despite the progress, application of insulation is still required to parts of structural steelwork to achieve over 60 minutes of fire rating. It is now recognised that uncertainties on insulation properties hinder adaptation of performance based designs for different types of structures. Intumescent coating has recently appeared to be one of most popular insulation types for steel structures, but its design method remains to be confirmed by empirical data, as technical difficulties on the determination of the material properties at elevated temperatures exist. These need to take into account of further physiochemical transitions such as moving boundary and endothermic reaction. The impetus for this research is to investigate the applicability of the conventional differential equation solution which examines the temperature rise on coated steel members by an inorganic intumescent coating, provided that the temperature-dependent thermal/mechanical insulation properties are experimentally defined in lab scale tests.

경년열화에 의한 소형 환풍기의 전기화재에 관한 연구 (A Study on Electrical Fire of Small Ventilators due to Aged Degradation)

  • 임종룡;이성일
    • 한국안전학회지
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    • 제31권4호
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    • pp.22-26
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    • 2016
  • "Always-on" small ventilators are likely to experience thermal decomposition of insulating material due to thermal, electrical, mechanical and environmental influences, and lose insulating properties by the process of oxidation and physiochemical reaction. This increases the risk of electrical fire because of layer short, short circuit, overload and Plastics are usually used to make ventilator and ventilator enclosures since they make less noise and are cheaper. Although more preferred than iron, plastic, a combustible material, has a higher risk of fire. In this study, several experiments were carried out to find out how RCD(Residual Current Protective Device) and Thermal fuses, which are electric motor protection devices, work and what needs to be done to reduce the risk of fire.

고들빼기 추출물이 인지질막 Liposome의 안정성 및 유동성에 미치는 영향 (Effects of Godulbaegi Extracts on the Stability and Fluidity of Phospholipid Liposomal Membranes)

  • 배송자;노승배;정복미
    • 한국식품영양과학회지
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    • 제27권3호
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    • pp.508-517
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    • 1998
  • We investigated the effects of godulbaegi extracts on the physiochemical properties of biological membranes as membrane stability and fluidity employing the phospholipid liposomal membrances as a biomembrane-mimetic system. The addition of the godulbaegi extracts to the phospholipid exterted great effects stagbilized the barrier function of the liposomal membranes in proportion to the concentration of the additive and significantly increased the membranes fluidity. The values of the fluorescence polarization of 1,6-diphenyl 1,3,5-hexatriene (DPH) decreased gradually as the temperature increased, and decreased abruptly near the phase transition temperature (Tm) of the liposome from gel to liquid crystalline state as usual. These results suggest that the activities of the godulbaegi extracts to enhance the stability and fluidity of the liposomal membranes have implication in their biological activities.

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스피넬상 ${LiMn_2}{O_4}$의 합성과 수소환원에 의한 활성화 (Synthesis of Spinel Phase ${LiMn_2}{O_4}$ and its Activation by Hydrogen Reduction)

  • 이동석;류대선;임병오;이풍헌
    • 한국세라믹학회지
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    • 제37권6호
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    • pp.564-568
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    • 2000
  • Spinel LiMn2O4 catalyst with submicron and single phase particles was synthesized at 48$0^{\circ}C$ for 12 hr in air by a sol-gel method. The spinel LiMn2O4 was deoxidized by hydrogen at various temperatures. Effects of physiochemical properties of the catalyst reduced by hydrogen were examined with X-ray diffractometer, thermogravimetric analysis and scanning electron microscope. The decomposition rate of carbon dioxide was measrued using the catalyst deosidized at 35$0^{\circ}C$.

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택사의 생약학적 연구 (Pharmacognostical Studies on Alisma Plants)

  • 도정애
    • 생약학회지
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    • 제26권4호
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    • pp.411-418
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    • 1995
  • In order to clarify the originality of several Alisma Rhizomes, we investigated the differences of their morphological, anatomical and physiochemical characteristics. Morphological observation shows the variability of Alisma shape and quality. The diversities in morphological shapes and qualities of tuber were observed among different origins. Chinese product looked like corm shape, but korean's irregular shape. The microscopic observation of korean Alisma revealed the presence of irregular vascular bundle which was scattered transversely and longitudinaly, which was different from that of the rhizome. This facts suggest that the portion of crude drug in Alisma should be the corm rather than the rhizome. In the physicochemical differences, chinese Alisma contains larger amount of mineral elements such as K, Na and Ca than korean Alisma. On the contrary, protein contents in lyophilized powder of aqueous extracts in korean Alisma rhizome was significantly higher than chinese Alisma rhizome. The leaves and stems contained larger amount of Ca and Na than tuber, and may be used as the osmotic diuretics for chinese traditional medicine.

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New Fungicides: Opportunities and Challenges - A Case Study with Dimethomorph

  • Spadafora, V. J.;Sieverding, E.
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 1998년도 Proceedings of International symposium on Recent Technology of Chemical Control of Plant Diseases
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    • pp.50-69
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    • 1998
  • Dimethomorph is a novel fungicide with a high level of activity against diseases induced by certain Oomycetes, including fungal populations that are resistant to other products. In several ways, this fungicide illustrates the opportunities and challenges presented by many modern pesticides. The specific mode of action, which affects cell wall formation, is associated with a very high level of performance and low dose rates under field conditions. These low dose rates, combined with a low level of toxicity to non-target organisms present an outstanding safety profile. This same highly-specific mode of action, however, limits the spectrum of activity and suggests the need for a resistance management plan, both of which must be addressed in new product development. In addition, the biological and physiochemical properties of this, and other new products are not adequately described by the traditional classification of fungicides into“protectant”and“systemic”types. These unique profiles provide novel and useful products for disease control.

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Pseudomonas aeruginosa가 생산하는 biosurfactant의 분리 및 특성 (Purification and Properties of Biosurfactant from Pseudomonas aeruginosa KK-7)

  • 김대원;김민주;강상모
    • 한국미생물·생명공학회지
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    • 제23권3호
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    • pp.337-345
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    • 1995
  • Biosurfactants produced by Pseudomonas aeroginosa KK-7 were purified and their properties were studied. The bacterial surfactant was seperated into two sorts of biosufactants (Type I, 11) by silica gel column chromatograpgy. On the basis of physiochemical analysis, Type I was found to be mixture of two glycolipids with M.W. 800, and Type II was peptide with M.W. 1300. The Type 11 biosurfactant was compose of glutamic acid, proline, glycine, leucine, histidine. The crude extract was used to dertermine some properties as a surfactant. The biosurfactant had the properties as stronger emulsification agent and a stronger stabilizing agent emulsion than any other surfactants tested.

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오징어(Todarodes paxificus) 식해 제조시 고춧가루 및 마늘의 발효최적 첨가량 최적 공정 개발 (Optimal Processing Conditions and Concentrations for Red Pepper Powder and Crushed Garlic in the Manufacture of Squid Todarodes paxificus Sikhae)

  • 김소라;한대원;임미진;조순영
    • 한국수산과학회지
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    • 제45권6호
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    • pp.640-647
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    • 2012
  • Squid Sikhae is a traditional salt-fermented food in Korea. We evaluated the standardization of optimal processing conditions for desirable quality-controlled squid Sikhae using analyses of physiochemical properties, microbiological species, and organoleptic tests. The optimal fermentation temperature, sun-dried sea salt concentration, and fermentation period for manufacturing squid Sikhae products of the aceeptable quality were $10^{\circ}C$, 4%, and 6 days. In addition, optimal concentrations of the additional ingredients of red pepper powder and crushed garlic for acceptable quality squid Sikhae were both 6%.