• 제목/요약/키워드: Swelling Ratio

검색결과 432건 처리시간 0.024초

식이섬유 첨가에 의한 백설기의 특성변화에 관한 연구 (Effect of Addition of Dietary Fibers on Quality of Backsulgies)

  • 최인자;김영아
    • 한국식품조리과학회지
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    • 제8권3호
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    • pp.281-289
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    • 1992
  • The physicochemical, rheological and sensory characteristics of Backsulgies added with dietary fibers-cellulose, pectin and wheat bran-were investigated. The maximum acceptable ratio of fibers was 10% for wheat bran or cellulose, 3% for pectin. As me results of physicochemical analysis, cellulose and pectin had larger water-binding capacity man wheat bran. Swelling power was increased with temperature increment. But the type of added dietary fiber did not make significant differences. The degree of gelatinization was measured by maltose content. The retrogradation of backsulgies was significantly delayed by the addition of dietary fibers. The retardation effect of dietary fibers for retrogradation of backsulgies was also proved by textural analysis and time constant determination of Avrami equation. Pectin had especially excellent delaying effect while me storage time extended. There were no significant differences in sensory characteristics between me backsulgi with no dietary fibers and backsulgies added with cellulose 3%, pectin 1% and wheat bran 3%. Therefore, we concluded mat cellulose 3%, pectin 1% and wheat bran 3% were me optimum addition ratios, which have the delaying effect of retrogradation, and which could be accepted as same as conventional backsulgies organoreptically.

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A Study on Composites of Ethylene-Vinyl Acetate Copolymer and Ethylene-Propylene-Diene Rubber with Aluminum Hydroxide as a Fire Retardant

  • Lee, Yu Jun;Lee, Su Bin;Jung, Jae Young;Lee, Dam Hee;Cho, Ur Ryong
    • Elastomers and Composites
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    • 제51권2호
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    • pp.93-98
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    • 2016
  • The composites of EVA/EPDM including aluminum trioxide (ATH) as a fire retardant were manufactured for the purpose of improving low temperature property and flame resistance in the rubbery materials. The ratio of EVA to EPDM didn't affect the flame resistance of the rubber composites. The addition of ATH resulted in increase of the flame resistance. In the evaluation of the cold resistance, the increasing EPDM content showed enhancement of cold resistance in the composites due to increasing low Tg EPDM. It was found out that tensile strengths of the composites showed a maximum value at 100 phr of ATH by reinforcing effect, but a minimum value at 200 phr of ATH owing to slippage between the flame retardant by the external stress. In the measurement of solvent resistance in tetrahydrofuran, the increasing ATH content yielded enhancement of solvent resistance by reducing swelling of the composite, and increasing EPDM content also resulted from increase of the solvent resistance by reduction of polarizability as well as increase of crosslink in the composites.

Evaluation of Physico-chemical Properties of Acrylic Resin Hydrogel and their Application to Transdermal Delivery System

  • Chung, Uoo-Tae;Choi, Seung-Man;Kang, Kee-Long;Kim, Nak-Seo;Chung, Youn-Bok
    • Archives of Pharmacal Research
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    • 제18권4호
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    • pp.224-230
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    • 1995
  • Recently, many attempts have been made to use hydrogels of various polymers as delivery systems of various drugs and bioactive materials to prolong and control their phamacological activities. In this study, we have evaluated the physico-chemical properties of methacrylic acid-methyacrylic acid methyl ester copolymer 9Eudispert mv)m a acrylic resin hydorgel, and its application to transdermal delivery system. In the dissolution tests, the release rate of salicylic acid (SA) and sodium salicylate (SOd. SA) were faster than lidocain (LD) and lidocain-HCl(LD-HCl). As the concentration of Eudispert mv polymer increased, the extensibility of Eudispert mu hydrogel decreased, whereas the swelling ratio increased. The more NaOH and polymer concentration increased, the more osmotic pressure linearly increased. The skin permeation of Sod. SA, an acidic model drug, was remarkably enhanced by Eudispert mv hydrogel. All fatty acids, except for Sod. glycolate, dramatically increased the skin permeation flux in Eudispert mu hydrogel containing LD-Hcl, a basic model drug. Consequently, it is suggested that Eudispert mv hydrogel may be used as potential transdermal delivery vehicle.

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반전유화법에 의한 유화아스팔트의 안정성 연구 (A Study on the Stabilization of Asphalt Emulsion with Phase Inversion Emulsification Method)

  • 허우성;이은경;최세영
    • Elastomers and Composites
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    • 제44권2호
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    • pp.143-149
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    • 2009
  • 본 연구에서는 아스팔트가 가지는 단점을 보완하고자 아스팔트를 비이온 계면활성제(Span 80, Span 60, Tween 80, 및 Tween 60), 음이온 계면활성제(SLS), 및 양이온 계면활성제(Imidazole)를 변량 배합하여 반전유화법으로 아스팔트 에멀젼을 제조하였다. 유화아스팔트의 안정성을 규명하고자 입자크기, 점도, 제타전위, 및 내수성을 고찰하였다. 비이온 계면활성제와 음이온 계면활성제를 혼합 사용할 경우 유화아스팔트의 안정성은 우수하였으며 계면활성제의 양이 증가함에 따라 입자크기는 감소하였고, 반면에 점도와 제타전위 및 내수성은 증가하였다.

PREPARATION OF POLYSTYRENE BEADS CONTAINING SULFONAMIDE GROUPS AND THEIR APPLICATION TO POLYMERIC BIOCIDES

  • Kim, Cheol-Jin;Kim, Jee-Yeon;Byun, Jang-Woong;Kim, Jae-Eun;Lee, Yoon-Sik;Yoon, Je-Yong
    • Environmental Engineering Research
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    • 제11권6호
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    • pp.325-332
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    • 2006
  • A novel series of polystyrene (PS) beads containing various sulfonamide groups was prepared, and their chemical stabilities in an aqueous solution were tested in order to determine their ability to inactivate microbes. By reacting aminomethyl polystyrene (AM PS) beads or carboxy polystyrene beads with various benzenesulfonic acid derivatives, the sulfonamide groups were introduced on the PS beads. The characteristics of the product beads were analyzed by elementary analysis after the substitution of various sulfonamide groups. Energy Dispersive Spectroscopy (EDS), and FT-IR analysis were used to analyze the elemental functional group composition, respectively. The hydrolytic stabilities of the PS beads containing various sulfonamide groups along with the relationship between the swelling ratio and their hydrophilicity were investigated. The antibacterial activity of the beads was determined by their ability to inactivate E. coli. This study reports that PS beads containing sulfonamide groups had lasting antibacterial efficacy over a satisfactory period, whilst maintaining their chemical stabilities against hydrolysis. The 8 synthesized polymer beads exhibited antibacterial ability.

Physicochemical Properties of Chaga (Inonotus obliquus) Mushroom Powder as Influenced by Drying Methods

  • Lee, Min-Ji;Seog, Eun-Ju;Lee, Jun-Ho
    • Preventive Nutrition and Food Science
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    • 제12권1호
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    • pp.40-45
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    • 2007
  • The effects of drying methods on the physicochemical properties of chaga (Inonotus obliquus) mushroom powder were investigated. Scanning electron micrograph revealed that freeze drying produced smaller particle- sized samples which in turn resulted in higher porosity than did vacuum and hot-air drying. Samples prepared by freeze drying showed a significantly higher L*-value as compared with those prepared by hot-air drying and vacuum drying (p<0.05). The lightness (L*-value) significantly decreased with increasing relative humidity and storage temperature regardless of drying method (p<0.05). The yellowness (b*-value) increased significantly with increasing relative humidity (p<0.05). Browning index was significantly lower in samples prepared by freeze drying (p<0.05) but not significantly different between samples dried by hot-air and vacuum drying. Freeze dried sample exhibited a significantly higher degree of rehydration than other samples (p<0.05) probably due to the small particle size. Water solubility of the freeze dried sample was higher than those of the other methods while swelling ratio of the same sample appeared to be lower than those of others. Freeze dried chaga mushroom powder contained significantly lower amount of total phenolics and total sugar as compared to other samples (p<0.05).

악골에 발생한 낭종의 임상적 연구 (CLINICAL STUDY OF CYSTS IN THE JAWS)

  • 김경욱;김경욱;이재훈
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제21권2호
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    • pp.166-173
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    • 1999
  • A clinical study of selected patients with cyst which were managed in the Department of oral and maxillofacial sugery from March 1994 to February 1998 was done. An following results were obtained 1. Male were involved more than females by cyst in a ratio of 1.95:1 and most of the cases occurred in the secondary decades 2. The primary site of radicular cysts were the anterior incisor area, dentigerous cysts were anterior incisor area and canine area, incisive canal cysts were maxillary anterior area, odontogenic keratocyst were the mandibular ramus area. 3. The common symptoms were swelling(65 cases), pain(12 cases) and the mean duration of syptomatic period was 10 days. 4. The rates of histopathologic classification were radicular cyst(58%), dentigerous cyst(22%), incisive canal cyst(9%), odontogenic keratocyst(11%). 5. Average of Alk. phosphatase was 235(IU/L) at pre-twenty age and 102(IU/L) at post-twenty age. 6. In treatment modalities, enucleation was most common, odontogenic keratocyst was treated by enucleation and curettage for prevention of recurrence.

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알칼라인 연료전지용 다른 작용기들을 갖는 두 종류의 음이온 교환 막들의 특성 비교 (Comparison of Properties of Two Kinds of Anion Exchange Membranes with Different Functional Group for Alkaline Fuel Cells)

  • 이승연;유동진
    • 한국수소및신에너지학회논문집
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    • 제29권5호
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    • pp.458-465
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    • 2018
  • This study reports the fabrication of anion exchange membranes (AEMs) containing two kinds of functional groups: i) trimethylphosphite (TMP) and ii) trimethylamine (TMA). We carried out the synthesis of polymers to enhance thermal stability and ion conductivity. The alternative polymer was prepared using 2,2-bis(4-hydroxy-3-methylphenyl)propane and decafluorobiphenyl. The membrane was fabricated by solution casting method. The thermal stability of membranes was examined by TGA. The physiochemical properties of membranes were also investigated in terms of water uptake, swelling ratio, ion exchange capacity, and ion conductivity. The hydroxide ion conductivity of the membranes reached about 20.2 mS/cm for quaternary ammonium poly(arylene ether) (QA-PAE) containing TMA moiety and 5.1 mS/cm for quaternary phosphonium PAE (QP-PAE) containing TMP moiety at $90^{\circ}C$.

Effect of slag on stabilization of sewage sludge and organic soil

  • Kaya, Zulkuf
    • Geomechanics and Engineering
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    • 제10권5호
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    • pp.689-707
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    • 2016
  • Soil stabilization is one of the useful method of ground improvement for soil with low bearing capacity and high settlement and unrequired swelling potential. Generally, the stabilization is carried out by adding some solid materials. The main objective of this research was to investigate the feasibility of stabilization of organic soils and sewage sludge to obtain low cost alternative embankment material by the addition of two different slags. Slags were used as a replacement for weak soil at ratios of 0%, 25%, 50%, 75% and 100%, where sewage sludge and organic soil were blended with slags separately. The maximum dry unit weights and the optimum water contents for all soil mixtures were determined. In order to investigate the influence of the slags on the strength of sewage sludge and organic soil, and to obtain the optimal mix design; compaction tests, the California bearing ratio (CBR) test, unconfined compressive strength (UCS) test, hydraulic conductivity test (HCT) and pH tests were carried out on slag-soil specimens. Unconfined compressive tests were performed on non-cured samples and those cured at 7 days. The test results obtained from untreated specimens were compared to tests results obtained from soil samples treated with slag. Laboratory tests results indicated that blending slags with organic soil or sewage sludge improved the engineering properties of organic or sewage sludge. Therefore, it is concluded that slag can be potentially used as a stabilizer to improve the properties of organic soils and sewage sludge.

Study on Mechanical Properties Modification of Styrene Butadiene Rubber Composites Filling with Graphene and Molybdenum Disulfide

  • Xu, Li Xiang;Sohn, Mi Hyun;Kim, Yu Soo;Jeong, Ye Rin;Cho, Ur Ryong
    • 반도체디스플레이기술학회지
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    • 제18권3호
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    • pp.52-59
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    • 2019
  • Styrene-butadiene rubber (SBR) composites, incorporated with graphene, molybdenum disulfide and their hybrid in different filling ratio, were fabricated by a two roll-mill. The dispersion states of all the samples' matrix were employed by carbon black dispersion tester. The curing properties of the pre-vulcanized rubber composites were investigated, after molding by heating press machine, the tensile strength, storage modulus, friction coefficient, the swelling property had also been tested according to ASTM. The composite G1M10 (filling with 1 phr graphene and 10 phr molybdenum) showed the best mechanical properties and viscoelastic properties in this research with a better filler dispersion state and more compact matrix structure.