• Title/Summary/Keyword: swelling agent

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Structural and Physicochemical Properties of Dried Aloe Vera Gel Using DIS (Dewatering & Impregnation Soaking) Process (삼투탈수 알로에 건조제품의 구조적 및 물리화학적 특성)

  • Kim, Sung-A;Baek, Jin-Hong;Lee, Shin-Young
    • Food Engineering Progress
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    • v.13 no.1
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    • pp.24-31
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    • 2009
  • The structural and physicochemical properties of dried aloe vera gel by DIS (dewatering impregnation soaking) process under optimum conditions were investigated. FT-IR spectra for dried samples of DIS aloes showed the typical patterns of standard aloe polysaccharide, and surface structures by SEM (scanning electron microscopy) were similar to a gel-like structure. In case of physicochemical properties of dried aloe samples by DIS process, solubilities and swelling powers of control (not osmotic treated aloe), DIS (S) and DIS (G), samples treated by osmotic solution of 60% sucrose/0.25% NaCl and 50% glucose/0.5% NaCl, were 48.3-57.3% and 8.3-11.7%, respectively, showing no significant differences among samples, but swelling power of DIS (PEG), sample treated by using 50% polyethylene glycol as an osmotic agent was about 5 times higher that of control. Also, water holding capacities of control, DIS (S) and DIS (G) were similar to each other, but that of DIS (PEG) was about 5 times higher that of control. Oil holding capacities of control and DIS aloes maintained the 50.9-86.4% levels of water holding capacities showing no significant differences among samples. Rehydration ratio of DIS (PEG) aloes were significantly dependent on the temperature of rehydrated solvent (water), and rehydration ratio of not-fileted aloe was about two folds higher than that of fileted aloe.

Analysis of Number of Elastically Cross-links to Predict the Mechanical Properties of 3D Networked Poly(sodium acrylate) Gel (폴리아크릴산나트륨 3차원 네트워크 겔의 물성 예측을 위한 가교개수밀도 분석)

  • Kim, Sang Jin;Jeong, Hye-Won;Shin, Sung Gyu;Cho, Sung Woo;Jeong, Jae Hyun
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.1
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    • pp.300-308
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    • 2021
  • In this study, 3D networked poly(sodium acrylate) gel was polymerized and controlled with the crosslinking environment to evaluate the mechanical properties and swelling behavior. In general, as the degree of crosslinking in a pre-gelled solution increases, the swelling ratio of the 3D networked gel decrease while the mechanical strength of the gel increases. Interestingly, this study demonstrates that the polymerization and crosslinking efficiency in gelling process could be depended on the crosslinking environment by evaluating the number of elastically cross-links in 3D networked gel. As a result, the number of elastically corss-links would be changed with 3.6 times as varying of the crosslinking environment while keeping the degree of crosslinking. It is expected that the 3D networked gel would be optimized as an effective absorbing agent for VOCs by using the gel evaluation method based on the number of elastically cross-links.

Tuning the rheological properties of colloidal microgel controlled with degree of cross-links (가교도가 제어된 콜로이드 마이크로겔의 유변학적 물성 분석)

  • Han, Sa Ra;Shin, Sung Gyu;Oh, Seung Joo;Cho, Sung Woo;Jung, Naseul;Kang, Bu Kyeung;Jeong, Jae Hyun
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.2
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    • pp.645-655
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    • 2019
  • In this study, colloidal microgel with viscoelasticity were prepared by using dispersion containing physical crosslinking agents and microgels with various strengths depending on the degree of cross-links.As the chemical crosslinking agent PEGDA400 content increased, hydrogels have various physical properties the swelling ratio decreased from $2.0{\times}10^4%$ to $6.0{\times}10^3%$ and increased viscosity by about 60%. The colloidal microgel was prepared with micro hydrogel grinded to $100{\mu}m$ size and the rheological behavior was confirmed with physical cross linking agent. A colloidal microgel having various viscosities was prepared by controlling starch and alginate based on micro-hydrogel containing 0.75% (w/v) of PEGDA400. In conclusion, these results would be highly useful for applying as a product that can give various physical properties to the colloidal suspensions, cosmetics, paint, and food industry.

Synthesis of Surface Crosslinked Poly(sodium acrylate) for Delayed Absorption in Cement Solution (시멘트 수용액에서 흡수 지연을 위한 Crosslinked Poly(sodium acrylate)의 표면 가교)

  • Hwang, Ki-Seob;Jang, Seok-Soo;Jung, Yong-Wook;Lee, Seung-Han;Ha, Ki-Ryong
    • Polymer(Korea)
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    • v.35 no.4
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    • pp.363-369
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    • 2011
  • To study the effect of incorporation of a surface crosslinking layer on a crosslinked poly (sodium acrylate) (cPSA) absorbent with ethylene glycol dimethacrylate CEGDMA), we synthesized several surface crosslinked cPSAs with EGDMA by an inverse emulsion polymerization method to delay the absorption of excess water in concrete, Liquid paraffin was used as a continuous phase. cPSA was synthesized with acrylic acid (AA) neutralized with aqueous 8 M sodium hydroxide solution as a monomer, N,N-methylene bisacrylamide (MBA) as crosslinking agent and ammonium persulfate (APS) and sodium metabisulfite (SMBS) as a redox initiator system by inverse emulsion polymerization. FTIR spectroscopy was used to characterize $Ca^{2+}$ ion interaction with cPSA and cPSA-EGDMAs. The swelling ratios of synthesized absorbents were evaluated from the absorption in deionized water, cement saturated aqueous solution and aqueous solution of calcium hydroxide (pH 12). Equilibrium swelling times for cPSA and surface crosslinked cPSA with EGDMA were 2 and 3 hrs, respectively. We also observed an increase in setting time of the cement and an increase in the compressive strength of mortar by addition of the synthesized cPSA-EGDMA.

Antifungal Mechanism and Properties of Antibiotic Substances produced by Bacillus subtilis YB-70 as a Biological Control Agent

  • Kim, Yong-Su;Kim, Sang-Dal
    • Journal of Microbiology and Biotechnology
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    • v.4 no.4
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    • pp.296-304
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    • 1994
  • Antibiotic substances were produced by Bacillus subtilis YB-70, a potential biocontrol agent found to suppress root-rot of eggplant (Solanum melonggena L) caused by Fusarium solani, in a dextrose glutamate medium and isolated by isoelectric precipitation. Partial purification was performed by column chromatography on silica gel with two solvent systems: chloroform-methanol and methanol-chloroform-water as eluting solvents, This active fraction YBS-1 s contained antifungal activity were soluble in ethanol, methanol, and water, but were not soluble in other solvents including acetone, butanol, ethyl ether, dimethylformamide, propanol, and etc. High performance liquid chromatography and thin layer chromatographic separation of YBS-1s showed that they have been composed of three biological active bands that were named YBS-1A, -1B, and -1C. The substances were stable to heat and resistant to protease. YBS-1s were active against a wide range of plant pathogenic fungi but did not inhibit the growth of bacteria and yeasts. They were not only fungicidal but also fungistatic against chlamydospores of F. solani. The $ED_{50}$ values for the chlamydospore germination and the germ-tube growth of F. solani were $O.725\mu\textrm{m}/ml\;and\;O.562\mu\textrm{m}/ml$, respectively. Microscopic observations proved the substances restricted the growth of phytopathogenic fungus F. solani by spore burst followed by dissolving of its germ-tube, and caused abnormal hyphal swelling after application to chlamydospores or growing hyphae. Cultural filtrate of B; subtilis YB-70 also suppressed the development of root-rot of eggplant in pot tests.

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Performance Evaluation of Mortar Containing Mechanochemical Treated Self-Healing Admixtures (기계·화학 처리 자기치유 혼화재가 포함된 모르타르의 성능평가)

  • Park, Dong-Cheol;Kwon, Hyuk;Lee, Jung-Woo;Hwang, Moo-Yeon;Kim, Tae-Hyung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.9 no.3
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    • pp.367-374
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    • 2021
  • In this study, the applicability of mechanochemical process for the manufacture of self-healing admixtures and the effect of mechanochemical process on the self-healing performance were evaluated. The self-healing admixtures were adopted as a highly reactive materials(expansive agent, swelling material and crystal growth agent) for mechanochemical processes. The self-healing admixtures for the mechanochemical process application were evaluated by X-Ray Diffraction and Fourier Transform Infrared Spectroscopy analysis, water permeability performance was used to evaluate self-healing performance of mortar. As a result of the evaluation, the self-healing performance of the WM(With-Mortar)3 sample to which mechanochemical process increased by 4.1% compared to the WM1 sample that was not treated, and the average healing index was 94.3%.

Effects of Anticaking Agents on the Physicochemical Properties of Freeze-dried Kiwifruit Powders (고화방지제의 첨가가 참다래 동결건조분말의 물리화학적 특성에 미치는 영향)

  • Oh, Hyun-Jeong;Lim, Ja-Hun;Lee, Ju-Yeon;Oh, Young-Ju;Lim, Sang-Bin
    • Culinary science and hospitality research
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    • v.20 no.1
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    • pp.178-188
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    • 2014
  • Two kinds of anticaking agents (dextrin, polydextrose) were combined with kiwifruit paste at 5% w/w ratio and freeze-dried to prepare a powdered material. The physiochemical characteristics of kiwifruit powders with anticaking agents were compared with those without anticaking agents as the control. The yield was higher in the powders with anticaking agents than the control. Moisture content, acidity, and total phenolics were lower in the powders with anticaking agents than the control. The contents of vitamin C was higher in the powders with anticaking agents than the control, but was no significant difference with different anticaking agent types. There were no significant differences in free sugar content (fructose, glucose, total sugar) and organic acid content (oxalic acid, lactic acid, total) depending on the anticaking agent types. Hunter's L-value was significantly high in the order of the samples with dextrin, the control, and polydextrose, while a-value showed an opposite tendency. Browning index, water solubility, and swelling power didn't show any significant difference. However, the hygroscopicities with elapsed time were lower in the powders with anticaking agents than the control. Therefore, the kiwifruit powder combined with dextrin or polydextrose as an anticaking agent at 5% w/w ratio could be used as a food biomaterial with a good quality in moisture, vitamim C, color value, browning index, water solubility, and hygroscopicity.

Case of Alergic Angioedema Caused by Arisaematis Rhizoma Ingestion (천남성(天南星)섭취에 의한 맥관부종 환자의 증례보고)

  • Sin, Sun-Mi;Cha, Ji-Hey;Kim, Gi-Tae;Byun, Sang-Hyuk;Ko, Heung;Leem, Kang-Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.1
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    • pp.259-262
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    • 2009
  • Angioedema is a localized transient swelling of sudden onset in the face, lips, tongue, hand, feet, respiratory system and gasteointestinal system. Angioedema is classified as allergy, hereditary, idiopathic or induced by medication as like aspirin, nonsteroidal anti-inflammatory agent, opiates, antibioics and angiotensin-coverting enzyme. Arisaematis Rhizoma Ingestion grows up every place in Korea, dries humidity and eliminates engorgement. so Arisaematis Rhizoma Ingestion was used to paralytic, hemiplegia, bell's palsy, tetanus. but Arisaematis Rhizoma Ingestion is toxic, can not be used pregnant women. We experienced a case of angioedema induced by Arisaematis Rhizoma Ingestion in a 52-years-old male patient who bited a Arisaematis Rhizoma Ingestion. We treated the patient based on traditional oriental medicine case report. As a result, the symtoms disappeard rapidly.

Pathways Analysis of Gleditsia spina Extract on Changes of Gene Expression in Human Melanoma cells (조각자(皂角刺)가 악성흑색종 세포주에 미치는 영향)

  • Kim, Bu-Yeo;Lim, Se-Hyun;Lee, Byoung-Ho;Lim, Chi-Yeon;Kim, Yong-Seong;Cho, Su-In
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.22 no.3
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    • pp.47-62
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    • 2009
  • Glenditsia spina (GS) can resolve carbuncle, relive swelling, dispel wind and destroy parasites. For these reasons, GS has been widely used as dermatologic agent clinically. In this study, the specific pathways of anti-proliferative effect of GS on human derived melanoma cells were identified. The molecular profile was measured using microarray technique to identify up- or down-regulated genes in SK-MEL-2 cell line. Pathway analysis was done by listing percentage of pathway involvement, and the represented pathways were obtained from KEGG. The transcription factor binding sequences were obtained by Transfac database. By the promoter analysis, up-regulated genes by GS were mainly associated with MAPK, Regulation of actin cytoskeleton, Wnt, Focal adhesion and Long term potentiation pathway. Down-regulated genes by GS were mainly associated with MAPK and Antigen processing and presentation pathway. And some of the transcription factors like Sp1 and NF-Y in up-regulated genes and Oct-1 in down-regulated genes by GS also identified.

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Pore-filling anion conducting membranes and their cell performance for a solid alkaline fuel cell (세공충진 음이온 전도성막의 제조 및 이를 이용한 고체알칼리 연료전지 성능 평가)

  • Choi, Youngwoo;Lee, Misoon;Park, Gugon;Yim, Sungdae;Yang, Taehyun;Kim, Changsoo
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.129.2-129.2
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    • 2010
  • AEM which were used for solid alkaline fuel cell(SAFC) were prepared by photo polymerization in method pore-filling with various quaternary ammonium cationic monomers and crosslinkers without an amination process. Their specific thermal and chemical properties were characterized through various analyses and the physico-chemical properties of the prepared electrolyte membranes such as swelling behavior, ion exchange capacity and ionic conductivity were also investigated in correlation with the electrolyte composition. The polymer electrolyte membranes prepared in this study have a very wide hydroxyl ion conductivity range of 0.01 - 0.45S/cm depending on the composition ratio of the electrolyte monomer and crosslinking agent used for polymerization. However, the hydroxyl ion conductivity of the membranes was relatively higher at the whole cases than those of commercial products such as A201 membrane of Tokuyama. These pore-filling membranes have also excellent properties such as smaller dimensional affects when swollen in solvents, higher mechanical strength, lowest electrolyte crossover through the membranes, and easier preparation process compared of traditional cast membranes. The prepared membranes were then applied to solid alkaline fuel cell and it was found comparable fuel cell performance to A201 membrane of Tokuyama.

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