• Membrane Journal
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• v.30 no.1
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• pp.9-20
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• 2020

Membranes are used in most processes of biopharmaceutical production. It is used for pretreatment of other processes, separation of impurities in the process, virus removal, control of products concentration and buffer solution exchange. Virus filters play an important role in ensuring product efficacy and stability because viral contamination of biopharmaceuticals for humans is a sensitive issue that is directly related to serious clinical outcomes. Virus filters typically have complex multilayer structures made of various polymers such as surface-modified PVDF, PES, CRC. Depending on the manufacturer, filters have different pore structures and shapes, such as symmetric or asymmetric, and is used in the form of pleated membrane, flat sheets or hollow fibers. Virus filters are exclusively supplied by few foreign companies such as Asahi Kasei, Millipore, Pall and Sartorius. Replacing virus filters can be time consuming and expensive, including approval from regulatory agencies through validation. As localization has become important due to Japan's recent export regulations, it is necessary to increase the degree of technical independence.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.3
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• pp.1-10
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• 2012

In spite of high resistant to corrosion and its strength, over the last two decades, concerns still remain about the durability of FRP materials under severe environmental and thermal exposures. In this paper, authors experimentally examine the combined degradation by thermal and chemical attacks in heterogeneous FRP rebar be made up with various fibers and resins. Five types of Carbon, Glass and Hybrid FRP rebars had manufactured by different process and surface patterns are adopted for the experiments such as weight change, interlaminar shear strength, SEM and FT-IR analysis. FRP specimens were immersed in alkaline or distilled solution up to 150 days and then thermal exposed on 60, 100, 150 and $300^{\circ}C$ for 30 minutes. From the test results, the degradation of FRP bars are influnced by the resin type and manufacturing process as well as the fiber, and ILSS of exposed FRP bar in solutions is slightly increased in initial stage and then decresed with the passing of immersed time. But, in this test, it is observed that the discrepancy of ILSS between degraded by alkaline solution and distilled water is negligible value.

• Journal of Oral Medicine and Pain
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• v.19 no.1
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• pp.125-136
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• 1994

Observation of elastic fiber's change of mouse TMJ due to several round factor, principally external stimulations, their influence on the TMJ structure's change and the analize of the consecutive evolution of the disease in most important. So, the author believe that the factor of TMJ feature is the elastic feature's change and it's the principal factor of the TMJ disease. For observation of the increase and disposition of elastic fiber that to regulate the elastic feature of tissue and allow it existence. For this propose, observation with histologic methods on 20mouse ICR of 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks. The results were as follow : 1. In the early stage, the condyle of TMJ is originated from cartilage mass, and it's calcification is endochondral. 2. In the early stage, the disc is relatively thin and immature, but in the later stage the fiber is dense and the disposition is most functional. 3. Observation of the early stage, the elastic fiber is a thin fiber that to across antero- posterior direction, but in the later stage elastic fiber are developed, the disposition that in the early stage was perpendicular to articular surface, now in parallel. 4. The elastic fiber was observated most clearly in the retrodiscal tissue. 5. In conclusion, the elastic fiber is observed like a thin fiber 1 week from born, but the fiber to increase the weight and it dispose functionally, and 4 week from born, it can realize the normal function.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.405-408
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• 2008

The most effective factors that improve sections and elongate spans of the prestressed concrete girders are shapes of sections and strengths of concretes, and the concrete strength is more influenced to enhance the allowable tensile strength on top and bottom fibers than increasing of flexural strength of girders. In this study, 60 MPa high-strength prestressed concretes were constructed at the Wonsoo Bridge where in the 1st section of expanding constructions of the Nonsan to Junjoo Expressway, the high-strength concrete was placed on the eight- 35 meters simple span IPC girders of four lanes of Nonsan direction. During casting of girder concretes, quality controls were carried out with continuing controls of surface moistures and corrections of the unit water using the air-meter methods right after batching. It was confirmed that compressive strengths of girder concretes ensure the target strength and the heat of hydrations of girder concrete were measured. Though using same materials and constructing methods, there're a wide range of strengths of each girder, so, when high-strength concretes cast in the place hereafter, a countermove should be prepared.

• Fashion & Textile Research Journal
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• v.7 no.5
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• pp.547-552
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• 2005

The study has objective in raising value of the gray color as a meaningful color suiting sentiments of modern people by expressing the gray color in various perspective utilizing natural dyes that is natural at the same time having aesthetic color tones. For example, the main ingredient used for coloring black and gray color is the pyrogallol tannin and the gray tone dye can be acquired by combining the tannin with iron. In order to find the suitable condition for processing tannin, UV-Vis part absorption spectrum of Gallapple pyrogallol tannin, dye ability based on temperature and time, reflection rate based on concentration, color changes based on acid treatment and alkali treatment, changes on surface based on concentration or metal mordant condition, and lightfastness were measured. Maximum absorption wavelength (${\lambda}_{max}$) of Gallapple tannin was at around 273 nm, while strong absorption was also observed at below 350 nm. Dye ability of Gallapple tannin is done more easily on silk rather than cellulose fibers such as cotton, while the optimum condition for dyeing was observed to be at $60^{\circ}C$, for 20 minutes. As a result of acid treatment, the color of dye material consist highly of gray tones and showed red tone after the alkali treatment. While it was observed that as dye concentration and metal mordant concentration increased the color changed at counter-clockwise direction on the Y-scale of Munsell's scale of colors. Lightfastness was more on a normal fading. I hope this study opens up possibilities towards presenting gray color expressed from tannin as color with diversity and aesthetic value. In future, comparative study between dye expressed from catechol tannin dye materials will be helpful.

• Fashion & Textile Research Journal
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• v.8 no.3
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• pp.343-348
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• 2006

This study aims to attain gray tone dyed goods by using tannin that is contained in green tea. Tannin is given general name of polyphenol, which has a characteristic that bonds with protein and it is used for food preservative that protects against bacteria, as well as its purpose of black tone dye for silk treatment that has been processed since its early ages. In particular, as tannin reacts with all kinds of metallic mordant and changes to various colors, when tannin acid is combined with iron, it becomes tannin steel and produces gray tone color. Tannin that is contained in green tea is condensed tannins and its structure does not hydrolyze, thus having flavan type structure. In order to find the suitable condition for processing tannin, UV-Vis part absorption spectrum of green tea tannin, dye ability based on temperature and time, reflection rate based on concentration, color changes based on acid treatment and alkali treatment, changes on surface based on concentration or metal mordant condition, and lightfastness were measured. Maximum absorption wavelength (${\lambda}_{max}$) of green tea tannin was at around 273nm, while strong absorption was also observed at below 350 nm. Dye ability of green tea tannin is done more easily on silk rather than cellulose fibers such as cotton, while the optimum condition for dyeing was observed to be at $60^{\circ}C$, for 20 minutes. As a result of acid treatment, the color of dye material consisted highly of gray tones and showed overall gray tone with the combined color of yellow and red after the alkali treatment. While it was observed that as dye concentration and metal mordant concentration increased, the color changed at counter-clockwise direction on the Y-scale of Munsell's scale of colors. Additionally, lightfastness was more on a normal fading.

• The Journal of Advanced Prosthodontics
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• v.7 no.6
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• pp.484-495
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• 2015

PURPOSE. This study was to evaluate the effects of bacterial cellulose (BC) membranes as a barrier membrane on guided bone regeneration (GBR) in comparison with those of the resorbable collagen membranes. MATERIALS AND METHODS. BC membranes were fabricated using biomimetic technology. Surface properties were analyzed, Mechanical properties were measured, in vitro cell proliferation test were performed with NIH3T3 cells and in vivo study were performed with rat calvarial defect and histomorphometric analysis was done. The Mann-Whitney U test and the Wilcoxon signed rank test was used (${\alpha}<.05$). RESULTS. BC membrane showed significantly higher mechanical properties such as wet tensile strength than collagen membrane and represented a three-dimensional multilayered structure cross-linked by nano-fibers with 60 % porosity. In vitro study, cell adhesion and proliferation were observed on BC membrane. However, morphology of the cells was found to be less differentiated, and the cell proliferation rate was lower than those of the cells on collagen membrane. In vivo study, the grafted BC membrane did not induce inflammatory response, and maintained adequate space for bone regeneration. An amount of new bone formation in defect region loaded with BC membrane was significantly similar to that of collagen membrane application. CONCLUSION. BC membrane has potential to be used as a barrier membrane, and efficacy of the membrane on GBR is comparable to that of collagen membrane.

• Journal of Sasang Constitutional Medicine
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• v.14 no.3
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• pp.114-131
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• 2002

1. PURPOSE : The purpose of this study is to investigate the effect of Chungpyesagantang on LPS induced Arthritis in Mice. 2. METHOD : All the BALB/C Mice used in this study were 4wks of age at the start of the experiment. The experimental model of Arthritis was induced by injectection of $300{\mu}g/kg$ LPS in mice knee joint. The experiment was compare daily CS treatment group after Arthritis elicitation with Arthritis elicitated group at day 4, 7, 14 after Arthritis elicitation. 3. RESULTS 1) The hyperplasia of synoviocytes of CS treatment group after Arthritis elicitation is soften than Arthritis elicitated group. 2) The aggregation of collagen fibers CS treatment group after Arthritis elicitation is decreased than Arthritis elicitated group. 3) The distribution of TUNEL positive cells(apoptotic cell) of CS treatment group was remarkably increased than Arthritis elicitated group. 4) The distribution of $TNF-{\alpha}$, $NF-{\kappa}B\;p50$, COX-2 positive cells of CS treatment group after Arthritis elicitation in synovial membrane was decreased than Arthritis elicitated group. 5) The distribution of $IL-2R-{\alpha}$, ICAM-1 positive cells of CS treatment group after Arthritis elicitation in apical surface of synovial membrane was decreased than Arthritis elicitated group. 6) The distribution of $NF-{\kappa}B\;p50$, $IL-2R-{\alpha}$ in common iliac lymph node of CS treatment group after Arthritis elicitation positive cells was decreased than Arthritis elicitated group. 4. CONCLUSION : As a result of these experimental results, it may be concluded that Chungpyesagantang used for treatment of LPS induced Arthritis in Mice. Inflamation activity in CS treatment group after Arthritis elicitation was decreased than Arthritis elicitated group.

• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.56-60
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• 2018

There have been a lot of study to improve the performance of membrane filters as the removal of particulate matter has been of great interest due to the negative effects. Among the membrane fabrication techniques, the electrospinning technique is the most promising because it can produce uniform fibers ranging from nano to micrometer size. The electrospun membranes will greatly improve the filtration performance due to the high ratio of surface area to volume and the high porosity. In the present study, polystyrene (PS) and cellulose acetate (CA) polymers were used to produce the membranes with carbon nanotube (CNT), showing the filtration performances were improved with the optimal amounts of CNT.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.11
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• pp.865-871
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• 2017

In this paper, a gelatin layer was formed on the surface of the twisted fiber-optic couplers fabricated by hydrofluoric acid, which can be used to measure relative humidity. The proposed method of sensors has advantage of low cost compared with the sensors based on the conventional electronic devices and takes beneficial characteristics of optical fibers and light. The fiber-optic sensors presented in this study show a measurement from about 40% to 85% relative humidity, and the experimental results agree well with the calculated results. Based on the design presented in this paper, the structure will enable promising applications in the detecting humidity and various hazardous gases.