• 제목/요약/키워드: Fibrous material

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A Study on the Removal of Phosphorus from Wastewater by Redox Reaction of Cu-Zn metal alloy (Cu-Zn 금속합금의 산화 환원 반응을 이용한 수중 탈인처리에 관한 연구)

  • Kim, Tae-Kyeong;Kim, Jong-Hwa;Song, Ju-Yeong
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.1
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    • pp.78-84
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    • 2015
  • The purpose of this study is to evaluate the removal efficiency of phosphorus from synthetic waste water by reduction and oxidation reaction of Cu-Zn metal alloy. Cu-Zn metal alloy applied in this study is composed of 40% of Zn and 60% of Cu, which is so called Muntz metal. And the fibrous type of metal alloy has approximately $200{\mu}m$ of thickness. Metal is oxidized in an aqueous solution to generate electron and metal ion. The mechanism of phosphate treatment is co-precipitation of metal ion and phosphorous ion at various pH and temperature. The treatment efficiency showed the maximum at a one cycle treatment. This result means that the surface area of reaction material is sufficient enough to get reaction equilibrium. Experiment is conducted at various pH from 5 to 9, and showed the maximum efficiency at pH 8. Phosphorous is dominated as a type of $H_2PO_4{^-}$ and $HPO_4{^{2-}}$ at this pH condition. We could not consider the temperature effect independently, because phosphorous removal efficiency showed such a complex mechanism. We could get high efficiency at lower temperature in this research.

The Strengthening Effects of Concrete Columns Confined with Carbon Fiber Sheets along the Fiber Direction (탄소섬유쉬트 올방향에 따른 콘크리트 기둥 보강성능)

  • Kim, Yang-Jung;Hong, Gap-Pyo
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.4
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    • pp.326-332
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    • 2011
  • Carbon, Aramid, Boron and Glass fibers are used as fibrous materials to promote structural bearing strength. Of these fiber types, carbon fiber is the most commonly used material, and is characterized by having a one-way direction, which is strengthened by tensile strength due to the attached direction only, while other types of fibers are two-way. Therefore, when applied in the field, the attachment direction of fiber is a very important factor. However, when fiber direction is not mentioned in the design drawing, there sometimes is no improvement in structural strength, as the fiber is being installed by a site engineer or workers who lack structural knowledge. The purpose of this study was to propose an optimal direction of carbon fiber through a comparison & analysis of reinforcing efficiency with reinforced experimental columns that used carbon fibers in each of the inclined, horizontal and vertical directions. According to the results, horizontal direction in the reinforced column was improved by 153.43%, but vertical direction was 104.61% only, and it was understood this was due to increased tensile strength along the fiber direction. For this reason, it is necessary to include information regarding fiber direction in design and site management.

A Case of Canine Cholangiocarcinoma (개 담관세포암(膽管細胞癌)의 1예(例))

  • Cho, Sung Whan;Kim, Duck Hwan;Kim, Kyo Joon;Kwon, Oh Deog;Park, No Tai
    • Korean Journal of Agricultural Science
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    • v.13 no.2
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    • pp.311-317
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    • 1986
  • On 11-year-old female mixed-breed dog with chief complaints of existence of abdominal enlargement and anorexia was referred to the veterynary teaching hospital of Chungnam National University. The dog was diagnosed into cholangiocarcinoma by the result of the histopathological observation. The results observed are summarized as follows: The clinical signs were abdominal enlargement, anorexia, dyspnea and depression. There were marked increase in serum glutamic pyruvic transaminase(GPT), serum glutamic oxaloacetic transaminase(GOT), lactic dehydrogenase(LDH) and blood urea nitrogen(BUN). Serum total protein and albumin were slightly below normal. In gross finding, the liver was enlarged and friable with numerous white, cauliflower-like nodules over the surface and composed on cysts from 3 to 4 cm in diameter. The cystic lesions contained a yellow gelatinous material. Anatomically, this neoplasm was classified as intrahepatic bile duct carcinoma. Histologically, this neoplasm was combined tubular carcinoma with bile duct cystadenocarcinoma. The former were characterized by tubular structures lined by anaplastic cuboidal or columnar cells with diffuse fibrous stroma, and the latter by multiple cystic structures lined by simple and stratified cuboidal or columnar cells.

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Flux Melting Route to 2-and 3-dimensional Fibrous Potassium Titanates, K$_2Ti_{2n}O_{4n+1}$ (n = 2 and 3) (Flux 용융법에 의한 2차원 및 3 차원 구조의 티탄산칼륨 섬유의 합성)

  • Jin-Ho Choy;Yang Su Han;Seung Wan Song
    • Journal of the Korean Chemical Society
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    • v.37 no.8
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    • pp.765-772
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    • 1993
  • Two-dimensional potassium tetratitanate ($K_2Ti_4O_9$) and three-dimensional potassium hexatitanate ($K_2Ti_6O_{13}$) fibers have been prepared by the combined method consisting of the flux melting (1150$^{\circ}C$)-slow cooling (cooling rate = 5$^{\circ}C$/h) process from the starting raw materials of $K_2CO_3$, and $TiO_2$ with the flux of $K_2MoO_4$. It was found that the fiber growth reaction is strongly dependent upon the mole ratio of flux (F) to raw material (R), which is 7 : 3 (F : R) as for the optimum growth condition. Relatively long fibers (average length ${\thickapprox}$ 4 mm) with a mixture of $K_2Ti_4O_9$ (major) and $K_2Ti_6O_{13}$ (minor) could be obtained when the reaction was carried out for the $K_2MoO_4-$K_2O{\cdot}4TiO_2$ (F : R = 7 : 3) system, but for the $K_2$MoO_4$-$K_2O{\cdot}6TiO_2$ (F : R = 7: 3) one, only the short fibers with ${\thickapprox}$ 2 mm long could be grown as the mixed phase of $K_2Ti_6O_{13}$ and $K_2Ti_4O_9$.

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Effect of tetracycline-HCl root conditioning on gingival epithelial cell attachment to root surface (염산테트라싸이클린으로 처리한 치근면의 치은상피세포부착에 관한 연구)

  • Hwang, Na-Young;Park, Byung-Ki;Kim, Sang-Mok;Kuk, Jung-Ki;Park, Ju-Chul;Kim, Byung-Ock
    • Journal of Periodontal and Implant Science
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    • v.32 no.1
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    • pp.13-23
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    • 2002
  • The ultimate goal of periodontal therapy is directed to arresting the progression of the disease, and regenerating the fibrous attachment. In order to achieve such treatment aim, the plaque and calculus must be eliminated and the physiological conditions of the root surface must be changed to facilitate the attachment and migration of the new fibroblasts, The method of changing the proper root surface conditions to promote the healing of periodontal tissue involves mechanical procedures, such as scaling and root planing, and chemical procedures such as tetracycline-HCl. However, the formation of a long junctional epithelium was most frequently observed type of healing. Thus, the aim of this study was to examine in vitro the influence of surface conditioning of dentin by TC-HCl on human gingival epithelial cell attachment. Human gingival epithelial cells were obtained from healthy retromolar pad area(under the age 23 years). Seventy two teeth extracted from severe periodontitis were used as study material. To evaluate the epithelial cell attachment to dentin, the prepared specimen was divided to four groups. For the control group, only scaling and root planing were carried out, and for the test group, 1 to 3, the concentration of the TC-HCl was 50, 125 and 250mg/ml respectively. After cell cultivation time of 1-, 3-. 24 hour, for the indirect quantitative assessment of gingival epithelial cell attached to dentin sample, the absorbance of epithelial cell unattached to dentin was measured. The results were as follows; 1. There was no statistically significant difference between scaling and root planing group and TC-HCl 50mg/ml 125mg/ml and 250mg/ml group about absorbance of unattached epithelial cell to dentin sample(p>0.5). 2. As time passes, the absorbance of unattached gingival epithelial cell to dentin sample was decreased statistically significant(p<0.05). 3. There was no statistically significant difference among the TC-HCl group(p>0.05) We concluded that there was similar effect on gingival epithelial cell attachment between TC-HCl conditioning on root surface and only scaling and root planing treatment

Synthesis of Nitrogen-Doped Porous Carbon Fibers Derived from Coffee Waste and Their Electrochemical Application (커피 폐기물 기반의 질소가 포함된 다공성 탄소 섬유의 제조 및 전기화학적 응용)

  • Dong Hyun Kim;Min Sang Kim;Suk Jekal;Jiwon Kim;Ha-Yeong Kim;Yeon-Ryong Chu;Chan-Gyo Kim;Hyung Sub Sim;Chang-Min Yoon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.31 no.1
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    • pp.57-68
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    • 2023
  • In this study, coffee waste was recycled into nitrogen-doped porous carbon fibers as an active material for high-energy EDLC (Electric Double Layer Capacitors). The coffee waste was mixed with polyvinylpyrrolidone and dissolved into dimethylformamide. The mixture was then electrospun to fabricate coffee waste-derived nanofibers (Bare-CWNF), and carbonization process was followed under a nitrogen atmosphere at 900℃. Similar to Bare-CWNF, the as-synthesized carbonized coffee waste-derived nanofibers (Carbonized-CWNF) maintained its fibrous form while preserving the composition of nitrogen. The electrochemical performance was analyzed for carbonized coffee waste (Carbonized-CW)-, carbonized PAN-derived nanofibers (Carbonized-PNF)-, and Carbonized-CWNF-based electrodes in the operating voltage window of -1.0-0.0V, Among the electrodes, Carbonized-CWNF-based electrodes exhibited the highest specific capacitance of 123.8F g-1 at 1A g-1 owing to presence of nitrogen and porous structure. As a result, nitrogen-contained porous carbon fibers synthesized from coffee waste showed excellent electrochemical performance as electrodes for high-energy EDLC. The experimental designed in this study successfully demonstrated the recycling of the coffee waste, one of the plant-based biomass that causes the environmental pollution into high-energy materials, also, attaining the ecofriendliness.

Material Characteristics and Provenance Interpretation for Chloritic Beads from the Boseong Geoseokri and Haenam Buntori Sites, Korea (보성 거석리 및 해남 분토리 유적 출토 녹니석제 구슬의 재질특성과 원산지 해석)

  • Kim, Ji-Young;Lee, Chan-Hee;Kim, Jin-Young
    • Journal of Conservation Science
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    • v.23
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    • pp.25-37
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    • 2008
  • This study focuses on identification of mineralogical and geochemical characteristics and interpretation of raw material sources for prehistoric chlorite beads excavated from Geoseokri site in Boseong and Buntori site in Haenam, Korea. These prehistoric beads consist of three grayish blue ring-shaped beads, one dark green tubular bead and one greenish black tubular bead that show acicular-columnar and fibrous microtexture. The beads are composed of $SiO_2$, $Al_2O_3$, MgO and FeO as majors and a trace amount of $K_2O$, CaO and Na_2O$. Mineral species is mostly chlorite with a small amount of quartz and feldspar. Quantitative analysis indicates that the grayish blue ring-shaped beads and the dark green tubular bead belong to clinochlore and the greenish black tubular bead does to the boundary between clinochlore and sheridantie. Chlorite is a hydrous phyllosilicate mineral and it shows various microtexture of acicular, sheeted, earthy, granular andfibrous shapes. As its hardness is 2, chlorite is easily engraved due to its softness. It has aesthetic worthy as it shows green, black and greenish gray colors and pearly to greasy luster as well. These factors would lead to the extensive use of chloritic beads as ornaments from prehistoric times. Though the mineral sources of the chlorite beads can be found in central western region of Chungnam and Iwon of Hamnam, those areas are too distant from the two relic sites. Instead, chlorite ores commonly occur as altered products in wall rock alteration zone of every hydrothermal deposit. Therefore, it is probable that raw materials of chlorite were supplied from neighboring hydrothermal environment rather than far deposits. The result needs further study to verify raw material provenance interpretation, supply, manufacture and distribution on the basis of archaeological points of view.

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Effects of natural eggshell membrane (NEM) on monosodium iodoacetate-induced arthritis in rats (MIA 유도 골관절염 랫드에 Natural Eggshell Membrane (NEM)이 미치는 영향)

  • Sim, Boo Yong;Bak, Ji Won;Lee, Hae Jin;Jun, Ji Ae;Choi, Hak Joo;Kwon, Chang Ju;Kim, Hwa Young;Ruff, Kevin J.;Brandt, Karsten;Kim, Dong Hee
    • Journal of Nutrition and Health
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    • v.48 no.4
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    • pp.310-318
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    • 2015
  • Purpose: The aim of this study is to investigate anti-arthritis activity using natural eggshell membrane (NEM). Methods: NEM was administered at 52 mg/kg, 200 mg/kg, and 400 mg/kg to SD-Rat, where arthritis was induced by monosodium iodoacetate (MIA) at 3 mg. NO production in serum was measured using Griess reagent. Cytokines including IL-$1{\beta}$, and IL-6 were measured by Luminex and $PGE_2$, MMP-2, MMP-9, TIMP-1, $LTB_4$, and hs-CRP were measured by ELISA. The cartilage of patella volume was examined and 3-D high-resolution reconstructions of the cartilage of patella were obtained using a Micro-CT system. Results: Production of NO, IL-$1{\beta}$, IL-6, $PGE_2$, MMP-2, MMP-9, TIMP-1, $LTB_4$, and hs-CRP in serum was decreased, respectively, in comparison with control. The cartilage of patella volume increased significantly. In addition, the NEM group showed a decrease in the cartilage of patella, synovial membrane, and transformation of fibrous tissue. Conclusion: The results for NEM showed significant anti-arthritis activity. These results may be developed as a raw material for new health food to ease the symptoms mentioned above.

Human Lung Cancer Cell Xenografts Implanted under the Capsule of Kidney, Spleen and Liver (폐암 세포주를 사용한 신, 비장 및 간 피막하 분식법의 비교)

  • 김수현;김종인;이해영;조봉균;박성달;김송명
    • Journal of Chest Surgery
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    • v.36 no.10
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    • pp.711-720
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    • 2003
  • Bakground : Complete resection by the surgery has been selected as the treatment of choice in lung cancer patients, but in cases of recurrence after excision or inoperable cases, the importance of anticancer chemotherapy has been emphasized. If one can select a set of the sensitive chemotherapeutic agents before anticancer chemotherapy, it will give more favourable results. Subrenal capsular assay has been recognized as a useful in-vivo chemosensitivity test of thoracic and abdominal tumors and it can be done in a short time for a rapid interpretation of tumor responsiveness to anticancer chemotherapeutic drugs. It has been reported that various kinds of cancer cells can be implantable to the kidney, but so far there is no comparative study of xenogeneic cell implantation on liver, spleen and kidney. The author implanted the human lung cancer cells under the capsule of S.D rat's liver, spleen and kidney respectively and compared the pattern of growth and histology. Material and Method: After incubation of human lung cancer cell line (SW-900 G IV) in RPMI 1640 (Leibovitz L-15 medium) culture media, 3${\times}$3${\times}$3 mm size fibrin clots which contain 108 cancer cells were made. Thereafter the fibrin clots were implanted at subcapsule area of liver, spleen and kidney of S.D. female rat. For immune suppression, cyclosporin-A (80 mg/Kg) was injected subcutaneously daily from post-implantation first day to sixth day. The body weight was measured at pre and post implantation periods. The growth pattern and the size of tumor mass were observed and the pathologic examination and serum tumor marker tests were performed. Result: Body weight increased in both of control and experimental groups. Serum Cyfra 21-1 was not detected. Serum levels of CEA and NSE revealed no significant change. The SCC-Ag increased significantly in implanted group. The growth rate of human lung cancer cells which was implanted on spleen was higher than on liver or kidney. The surface area, thickness, and volume of tumor mass were predominant at spleen. The success rates of implantation were 80% on kidney, 76.7% on spleen and 43.3% on liver. Pathologic examination of implanted tumors showed characteristic findings according to different organs. Tumors that were implanted on kidney grew in a round shape, small and regular pattern. In the spleen, tumors grew well and microscopic neovascularization and tumor thrombi were also found, but the growth pattern was irregular representing frequent daughter mass. Human lung cancer cells that were implanted in the liver, invaded to the liver parenchyme, and had low success rate of implantation. Microscopically, coagulation necrosis and myxoid fibrous lesion were observed. Conclusion: The success rate of implantation was highest in the kidney. And the mass revealed regular growth that could be measured easily. The SCC-Ag was presented earlier than CEA or Cyfra21-1. The Cyfra21-1 was not detected at early time after implantation. The best model for tumor implantation experiment for chemosensitivity test was subrenal capsular analysis than liver and spleen and the useful serum tumor marker in early period of implantation was the SCC-Ag.

Video-assisted Talc Poudrage for the Treatment of Malignant Pleural Effusion: Analysis of Effects and Benefits (악성 늑막 삼출증에서의 비디오 흉강경하 탈크 분무의 효과 및 장점 분석)

  • Song, In-Hag;Chang, Won-Ho;Choi, Chang-Woo;Son, Jin-Sung;Kim, Dong-Hyun;Baek, Kang-Seok;Youm, Wook;Kim, Hyun-Jo
    • Journal of Chest Surgery
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    • v.40 no.7 s.276
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    • pp.492-498
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    • 2007
  • Background: Malignant pleural effusion is a common condition in neoplastic patients and palliative therapy is the usual treatment. Talc has been generally accepted to be the most effective sclerosant for chemical pleurodesis, but the optimal route of administration remains controversy. We compared the results of video-assisted thoracoscopic talc poudrage (VTP) with administering a bedside talc slurry through a chest tube (BTS) for the treatment of malignant pleural effusion. Material and Method: From December 2004 to May 2006, 20 patients with malignant pleural effusion underwent chemical pleurodesis via VTP (group A, n=10), and BTS (group B, n=10). Result: The durations of chest tube placement after the procedure were $7.0{\pm}4.0$ days (group A) and $6.7{\pm}3.6$ days (group B). The hospital stays were $24.3{\pm}9.4$ days (group A) and $30.7{\pm}21.5$ days (group B), respectively. The symptoms of dyspnea were much more improved in group A (p-value=0.014) after discharge (mean f/u group $A=8.5{\pm}2.2$ months, group B $8.0{\pm}7.4$ months). The collapsed portions of lung were better expanded in group A than in group B (p-value=0.011). Conclusion: We recommend VTP for the selected patients with malignant pleural effusion because of the advantages of dissecting the fibrous peel to relieve the atelectasis and dyspnea, and excising the pleura for diagnosis with direct viewing of the lesion.