• Title/Summary/Keyword: 메틸셀룰로스

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Extrusion of Pellet-type Adsorbents Employed with Alum Sludge and H2S Removal Performance (알럼 슬러지를 이용한 입상흡착제 압출 및 황화수소 제거 성능)

  • Park, Nayoung;Bae, Junghyun;Lee, Choul Ho;Jeon, Jong-Ki
    • Clean Technology
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    • v.19 no.2
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    • pp.121-127
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    • 2013
  • The objective of this study is optimization of extrusion process for preparation of pellet-type adsorbents employed with alum sludge. Effects of water content and methyl cellulose as a binder on the possibility of extrusion and physical properties of pellet-type adsorbents were investigated. The physical characteristics of the pellet-type adsorbents were studied using nitrogen adsorption and compression strength. With a ratio of water to sludge, 63/100, the adsorbent was well extruded with a cylindrical form and the compressive strength was the highest. With increasing methyl cellulose content, the compressive strength of pellet-type adsorbent could be improved, but the specific surface area decreased. The breakthrough time of the hydrogen sulfide could be increased significantly through calcination and the breakthrough capacity reached to 1,700 mg/g, which seems to be due to increase of surface area during calcination.

Pore Structure and Separation Properties of Thin Film Composite Forward Osmosis Membrane with Different Support Structures (지지층 구조가 다른 복합 정삼투막의 기공구조와 분리 특성)

  • Ahn, Soo-Hyun;Kim, In-Chul;Song, Doo-Hyun;Jegal, Jonggeon;Kwon, Young-Nam;Rhee, Hee-Woo
    • Membrane Journal
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    • v.23 no.3
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    • pp.251-256
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    • 2013
  • In this study, acetylated methyl cellulose (AMC) was successfully used as a support layer of thin film composite (TFC) forward osmosis (FO) membrane. A selective polyamide active layer, interfacially polymerized, was coated on top of various substrate layers. The structure and performance of the TFC FO membrane based on the AMC substrate were compared with those of TFC FO membranes with different polymeric support layers. The experimental results showed that the AMC FO membrane performance was better than other FO membranes due to its characteristic morphology and lower back diffusion rate of salts.

Analysis of Attenuation Differences According to Radiolucent and Radiopague Materials : Based on DECT (Dual Energy Computed Tomography) (방사선 투과 및 불투과성 물질에 따른 감약 차이의 분석 : DECT 검사 중심으로)

  • Jang, Hyon-Chol;Kim, Yoon-Shin;Kim, Hyeon-Ju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.3
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    • pp.1584-1589
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    • 2014
  • This study analyzed CT values of radiolucent and radiopaque materials by energy region after selecting radiolucent and radiopaque materials at random using GE's DECT((Dual Energy Com-puted Tomography) at S University Hospital located in Gyeonggi-province from July through August in 2013. Besides, it drew out the most analogous energy region to the value of 120kVp CT, which is applied to existing SECT(Single Energy Computed Tomography), by utilizing the analysis method of CT values and tried to find out the most useful and appropriate materials when contrast was applied within visible area in clinical application. As a result, there was little decrease of CT value after 90KeV in the case of materials with low density and high moisture content such as normal saline, methyl-cellulose and gels used in ultra-sonic waves test; energy does not influence much on materials with extremely low or high density such as air and contrast medium; methyl-cellulose and gels used in ultra-sonic waves test are considered to be the most useful materials for clinical applications.

Modified Upper Gastrointestinal Study Using Methylcellulose After Administration of Barium Suspension : Comparison with Conventional Series (바륨 현탁액과 메틸셀룰로스(Methylcellulose)를 사용한 변형 상부위장관조영술 :전통적 바륨조영술과의 비교)

  • 이기창;최민철;서민호;정주현;윤정희
    • Journal of Veterinary Clinics
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    • v.17 no.2
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    • pp.411-415
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    • 2000
  • For comparison with conventional barium-gastrointestinal study, modified method using barium and methylcellulose was performed in 16 normal dogs (4-8 kg) divided into two groups. The group 1 received 8ml/kg of 40% w/v barium suspension only, and group 2 had taken 15 ml/kg of 0.6% w/v methylcellulose after administration 4 ml/kg of 40% w/v barium suspension by feeding tube. The barium suspension was prepared mixing full strength-barium suspension with water and methylcellulose solution was produced by blending methylcellulose sterilized water Sequential radiographs, lateral and ventrodorsal projections were obtained at 5 minute, 20 minute,40 minute. 60 minute and every 30 minutes thereafter, until the contrast is seen in the large intestine Inage qual- ity was rated by three veterinary radiologists as " poor" " fair ". "good", or "excellent" We analyzed the relationship between image quality,, transit time. Between two techniques, the modified method with 4ml of 40% w/v barium suspension and 15 ml of 0.6% w/v methylcellulose showed much better image quality ["excellent" result in 7 of the 8 subjects (88%)] and shorter transit time (107 minutes) toe the cecum. In addition, the best image quality was obtained at 20 and 40 minutes after admin-istration of contrast agent. It call be concluded the modified gastrointestinal study using methylcel-lulose after administration of barium suspension was a simple technique and easily improved the image quality and diagnostic accuracy of gstrointestinal disorders in small animal.racy of gstrointestinal disorders in small animal.

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Applications of Enzyme Immobilized Membranes: A Review (효소 고정화막의 응용에 대한 총설)

  • Ryu, Junghyun;Patel, Rajkumar;Kim, Jong Hak
    • Membrane Journal
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    • v.31 no.6
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    • pp.393-403
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    • 2021
  • Enzymes are important class of catalyst for biotransformation. Stability and reusability of enzymes during the catalysis process is a key issue. Activity of enzyme can be enhanced by its immobilization on a suitable substrate by creation of specific microenvironment. A variety of membranes has been used as substrate due to the biocompatibility and simpler method to tune hydrophilicity/hydrophobicity property of the membrane surface. In this review, polymer membranes including cellulose, polyacrylonitrile (PAN), polydimethylsiloxane (PDMS), polyvinylidene fluoride (PVDF), polyethersulfone (PES) are introduced and discussed in detail. Biodegradation of organic contaminants by immobilized enzyme is an environmental friendly process to reduce the contamination of environment in pharmaceutical company and textile industries. The controlled hydrolysis of oil can be performed in enzyme immobilized membrane bioreactor (EMBR), resulting in reducing carbon emission and reduced environmental pollution. Bioethanol and biodiesel are considered alternative fossil fuels that can be prepared in EMBR.

Microencapsulation of aronia extract and stability of encapsulated anthocyanins during sulgidduk cooking (아로니아 추출물의 미세캡슐 제조 및 설기떡의 안토시아닌 안정성 연구)

  • Choi, Yeji;Koh, Eunmi
    • Korean Journal of Food Science and Technology
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    • v.54 no.2
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    • pp.163-170
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    • 2022
  • Aronia (Aronia melanocarpa cv. Viking) contains high amounts of anthocyanins, which are susceptible to heat. This study was conducted to identify an efficient coating material for encapsulating aronia extract to enhance the stability of anthocyanins during cooking. Maltodextrin, maltodextrin+gum Arabic, and maltodextrin+carboxymethyl cellulose were chosen as the coating materials, mixed with aronia extract at a ratio of 2:1, and freeze-dried after homogenization. The encapsulated aronia extract was then used as a sulgidduk ingredient. Sulgidduk prepared with the encapsulated aronia had significantly higher values for redness, anthocyanin retention, total phenolic content, and antioxidant activity compared to sulgidduk prepared with non-encapsulated aronia. In addition, the sensory evaluation revealed that sulgidduk prepared with encapsulated aronia produced better color and taste. These results indicate that the encapsulation of aronia extract improved the stability of the anthocyanins in aronia, and encapsulated aronia can be used as a functional colorant in the food industry.

Studies on Adsorption Behaviour for Heavy Metal Ions from Waste Water Using Eco-philic Cellulose Derivatives (환경친화형 셀룰로오스계 유도체의 합성 및 폐수내 중금속 이온 흡착거동 연구)

  • Lee, Soon-Hong;Bae, Joong-Don
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.11
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    • pp.1146-1152
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    • 2005
  • Graft copolymers were synthesized from methylcellulose(MC) and acrylic acid(AA) with active carboxyl groups in the presence of potassium persulfate($K_2S_2O_8$) initiator to enhance adsorption capacity of toxic heavy metal such as $Pb^{2+}$ and $Cu^{2+}$ from wastewater. The resulting grafted copolymers(MC-g-AA/PAA) were mixture of the graft copolymers from MC and AA(MC-g-AA) and polyacrylic acid homopolymers(PAA). The degree of palling was increased with rising concentration of monomer and initiator under the reaction conditions at $60^{\circ}C$, 3 hrs. The water insoluble property of MC-g-AA showed more than 19.7% degree of grafting. So that it could be an adsorbent of heavy metals. Adsorption characteristics of the MC-g-AA were evaluated depending on the degree of grading, pH of wastewater, adsorption time, dosage of MC-g-AA and concentration of heavy metals in the different conditions. Degree of grafting, and initial concentration of heavy metal ions increased, the adsorption amount of $Pb^{2+}$ and $Cu^{2+}$ increased, but added MC-g-AA increased, the adsorption amount per unit weight of $Pb^{2+}$ and $Cu^{2+}$ decreased. The MC-g-AA showed the high $Pb^{2+}$ and $Cu^{2+}$ adsorption amount in the range pH $4{\sim}6$. Also all of $Pb^{2+}$ and $Cu^{2+}$ ions reached in adsorption equilibrium in neighborhood 4 hours. The adsorption of heavy metals described by Freundlich isotherm, it was determined the value of l/n of $Pb^{2+}$ and $Cu^{2+}$ that 0.4294 and 0.3453, respectively.