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Improvement in functional properties of conger eel skin gelatin by succinylation (Succinylation에 의한 붕장어껍질 젤라틴의 기능성 개선)

  • Kim, Jin-Soo
    • Applied Biological Chemistry
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    • v.39 no.4
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    • pp.282-286
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    • 1996
  • To effectively utilize fish skin gelatin as a material for quality improvement in surimi gel from fish with a red muscle, conger eel skin gelatin was modified with succinic anhydride, and funtional properties such as emulsifying activity and emulsifying stability were determined. The degree of chemical modification incresed up to 0.3 g of succinic anhydride/g of gelatin, above this adding ratio a nearly constant value was reached. The maximum amount of modification was about 90%. The emulsifying activity and emulsifying stability of gelatin gradually increased up to 89.8% of succinylation extent, little changed above of succinylation extent. The other functional properties as solubility, water holding capacity, foam expansion and foam stability were improved following succinylation with 0.3 g of succinic anhydride/g of gelatin. Amino acid composition of succinylated gelatin was similar to that of unmodified gelatin. Heavy metal contents such as cadmium, lead, copper and zinc of succinylated gelatin were lower than those of unmodified gelatin.

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Serial Block-Face Imaging by Field Emission Scanning Electron Microscopy (전계방사형 주사전자현미경에 의한 연속블록면 이미징)

  • Kim, Ki-Woo
    • Applied Microscopy
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    • v.41 no.3
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    • pp.147-154
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    • 2011
  • Backscattered electrons (BSE) are generated at the impact of the primary electron beam on the specimen. BSE imaging provides the compositional contrast to resolve chemical features of sectioned block-face. A focused ion beam (FIB) column can be combined with a field emission scanning electron microscope (FESEM) to ensure a dual (or cross)-beam system (FIB-FESEM). Due to the milling of the specimen material by 10 to 100 nm with the gallium ion beam, FIB-FESEM allows the serial block-face (SBF) imaging of plastic-embedded specimens with high z-axis resolution. After contrast inversion, BSE images are similar to transmitted electron images by transmission electron microscopy. As another means of SBF imaging, a specialized ultramirotome has been incorporated into the specimen chamber of FESEM ($3View^{(R)}$). Internal structures of plastic-embedded specimens can be serially revealed and analyzed by $3View^{(R)}$ with a large field of view to facilitate three-dimensional reconstruction. These two SBF approaches by FESEM can be employed to unravel spatial association of (sub)cellular entities for a comprehensive understanding of complex biological systems.

Mechanical Properties and Flame Retardancy of Rigid Polyurethane Foam Using New Phosphorus Flame Retardant (새로운 인계 난연제 합성과 이를 이용한 경질 폴리우레탄 폼의 난연성 및 물성 분석)

  • Lee, Byoung Jun;Kim, Sang Bum
    • Applied Chemistry for Engineering
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    • v.27 no.6
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    • pp.577-582
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    • 2016
  • In this study, we compared and analyzed the flame retardancy and mechanical properties of three different rigid polyurethane foams (RPUF) containing noble non-halogen phosphorus flame retardant (BHP-RPUF) or halogen-phosphorus flame retardant (TCPP-RPUF) or no flame retardant material (Pure-RPUF). The noble phosphorus-based flame retardant, bis(3-(3-hydroxypropoxy)propyl) phenyl phosphate (BHP), was synthesized by the reaction between disodium phenyl phosphate and 3-chloro-1-propanol. Through universal testing machine (UTM) experiments, the compressive strength of BHP-RPUF was similar to that of TCPP-RPUF. From the result of foam morphology analysis, it was confirmed that BHP-RPUF has the lowest thermal conductivity of $0.023W/m{\cdot}K$. We also measured the size of air bubbles using reaction velocity and SEM, and analyzed how they affect the thermal conductivity. In addition, the heat-resisting property was investigated through TGA analysis. The limited oxygen index (LOI) test confirmed that BHP had the ability to increase the flame retardancy of RPUF.

A Study on Revision & Development on the 'Model -Curriculum of the Library Science of the Junior College (전문대학도서관과의 모형교육과정 수정개발에 관한 연구)

  • So Si Joong
    • Journal of the Korean Society for Library and Information Science
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    • v.18
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    • pp.213-276
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    • 1990
  • To revise and develop a 'Model' Curriculum for training the middle standing professionals equipped with professional technology and theories at the spot of the library, such process were executed as research on bibliographic material and literature, utilization of examination of various questionnaires, interviews with middle standing librarians at the spot of the library, a review on the operational state of the Professor's Association of Library Science of Junior Colleges, some consultation with the Research & Deliberation Committee on Curriculums, etc., and to review the present department of library science at the two-year course's short-term colleges or institutes in foreign countries, Germany which is thought to be similar to our nation's situations and its level of economy and Singapore which is considered to be a newly emerging nation were looked into typically. In particular, since studies on the curriculums of the Library Science Dept. of colleges had already preceded, thereby the framework of the 'Model' curriculum was already achieved, however to review how well such framework is applied to the spot of education and give some improvement on that, some unrelistic findings of different subjects in consideration with reality, while comparing those curriculum schedules of each Library Science Dept. with the 'Model' curriculum schedule, were supplemented or revised to be fit to reality. For some supplementing or revising proposals on the pre studied 'Model' curriculum, some tentative plans which focussed on each field respectively and some tentative plans which focussed on cultural subjects, required major subjects and elective subjects were suggested in duality to be referred to. On such a process of forming a harmony of educational theories and practice, it was planned to revise and develop curriculum in a sense emphasizing on practical exercise, and tried not to neglect on each of the fields of the curriculum centered on the areas of materials organization, linguistics, information resource, information science, library organization, & administration, etc. The study on curriculums should be performed flexible to be applied to the accelerating transition of sciences, and be good examples in instruction.

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The Effect of Oral High Protein Liquid on Nutritional Support in Patients Undergoing Radiotherapy for Head and Neck Cancer (두경부암 환자에서 방사선치료 중 고농축 고단백 균형 영양식의 영양보충효과)

  • Oh, Young-Taek;Kim, Soo-Hee;Kim, Chul-Ho;Lee, Sun-Young;Jang, Hyun-Soo;Cho, Sun-Mi;Choi, You-Young;Choi, Won-Sun;Yun, Sung-Seob
    • Korean Journal of Head & Neck Oncology
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    • v.24 no.2
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    • pp.184-188
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    • 2008
  • Objectives:Weight loss and malnutrition in patients undergoing radiotherapy for head and neck cancer are usual and preventable. The effect of nutritional support with oral high protein liquid was evaluated. Material and Methods:From Feb. to Dec. 2007, twenty patients received nutritional supplement with oral high protein liquid during radiotherapy for head and neck cancer and the nutritional status was evaluated. Weight loss was compared with control group of similar clinical characteristics. Results:Nutritional parameters such as weight, arm circumference, hemoglobin, hematocrit, total protein, albumin, transferring and the number of lymphocyte were relatively well maintained in patients with nutritional support with oral high protein liquid. In addition weight loss was minimal and significantly lower compared with control group. Conclusion:Nutritional support with oral high protein liquid was effective on maintaining nutritional status for the patients with head and neck cancer during radiotherapy.

Enamel pretreatment with Er:YAG laser: effects on the microleakage of fissure sealant in fluorosed teeth

  • Memarpour, Mahtab;Kianimanesh, Nasrin;Shayeghi, Bahareh
    • Restorative Dentistry and Endodontics
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    • v.39 no.3
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    • pp.180-186
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    • 2014
  • Objectives: The purpose of this in vitro study was to evaluate the microleakage and penetration of fissure sealant in permanent molar teeth with fluorosis after pretreatment of the occlusal surface. Materials and Methods: A total of 120 third molars with mild dental fluorosis were randomly divided into 6 groups (n = 20). The tooth surfaces were sealed with an unfilled resin fissure sealant (FS) material. The experimental groups included: 1) phosphoric acid etching (AE) + FS (control); 2) AE + One-Step Plus (OS, Bisco) + FS; 3) bur + AE + FS; 4) bur + AE + OS + FS; 5) Er:YAG laser + AE + FS; and 6) Er:YAG laser + AE + OS + FS. After thermocycling, the teeth were immersed in 0.5% fuchsin and sectioned. Proportions of mircoleakage (PM) and unfilled area (PUA) were measured by digital microscope. Results: Overall, there were significant differences among all groups in the PM (p = 0.00). Group 3 showed the greatest PM, and was significantly different from groups 2 to 6 (p < 0.05). Group 6 showed the lowest PM. Pretreatment with Er:YAG with or without adhesive led to less PM than bur pretreatment. There were no significant differences among groups in PUA. Conclusions: Conventional acid etching provided a similar degree of occlusal seal in teeth with fluorosis compared to those pretreated with a bur or Er:YAG laser. Pretreatment of pits and fissures with Er:YAG in teeth with fluorosis may be an alternative method before fissure sealant application.

In vitro cytotoxicity of four calcium silicate-based endodontic cements on human monocytes, a colorimetric MTT assay

  • Khedmat, Sedigheh;Dehghan, Somayyeh;Hadjati, Jamshid;Masoumi, Farimah;Nekoofar, Mohammad Hossein;Dummer, Paul Michael Howell
    • Restorative Dentistry and Endodontics
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    • v.39 no.3
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    • pp.149-154
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    • 2014
  • Objectives: This study was performed to evaluate the cytotoxicity of four calcium silicate-based endodontic cements at different storage times after mixing. Materials and Methods: Capillary tubes were filled with Biodentine (Septodont), Calcium Enriched Mixture (CEM cement, BioniqueDent), Tech Biosealer Endo (Tech Biosealer) and ProRoot MTA (Dentsply Tulsa Dental). Empty tubes and tubes containing Dycal were used as negative and positive control groups respectively. Filled capillary tubes were kept in 0.2 mL microtubes and incubated at $37^{\circ}C$. Each material was divided into 3 groups for testing at intervals of 24 hr, 7 day and 28 day after mixing. Human monocytes were isolated from peripheral blood mononuclear cells and cocultered with 24 hr, 7 day and 28 day samples of different materials for 24 and 48 hr. Cell viability was evaluated using an MTT assay. Results: In all groups, the viability of monocytes significantly improved with increasing storage time regardless of the incubation time (p < 0.001). After 24 hr of incubation, there was no significant difference between the materials regarding monocyte viability. However, at 48 hr of incubation, ProRoot MTA and Biodentine were less cytotoxic than CEM cement and Biosealer (p < 0.01). Conclusions: Biodentine and ProRoot MTA had similar biocompatibility. Mixing ProRoot MTA with PBS in place of distilled water had no effect on its biocompatibility. Biosealer and CEM cement after 48 hr of incubation were significantly more cytotoxic to on monocyte cells compared to ProRoot MTA and Biodentine.

A Study on Design Development of the Hotel Robe Based on Korean Images (한국 전통 이미지의 호텔용가운 디자인 개발에 관한 연구)

  • 문광희;문명옥
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.1
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    • pp.45-53
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    • 2004
  • This study was conducted to redesign hotel robes based on Korean images. Hotel robes are furnished at many Korean hotels to increase the level of their guests' satisfaction toward their hotel services. The current hotel robe has several flaws in utility and design. Also, the robes register a low level on guests' satisfaction while generating high cleaning cost. Consequently, improvements in the hotel robes' material, motifs, style, and color were needed. The current one-piece, cotton towel weave robes used in hotels are white and pale. Half of the hotel guests never wear the hotel robes during their stay, because they are unattractive and most Korean hotels provide a robe similar in design. Furthermore, these robes are undistinguishable from those found at other countries. Nevertheless, Korean hotel managers feel that the hotel robe is an important tool to express its hotel image and to increase guests' satisfaction of their services. Most hotel managers and consumers agreed that it is necessary to design hotel robes based on Korean images. They believe that redesigning the hotel robes based on Korean images would induce hotel guests to wear them and at the same time feel part of the Korean traditional culture. The Korean traditional motifs of Taegug, Un (cloud), JuJag (phoenix), and Kumkwan (gold crown) were used in the new design of the hotel robes. The style of new hotel robes is the Korean traditional Pho of the Three Kingdoms. The colors of new hotel robes are white and pink. Forty-three examiners evaluated the newly designed robes for their aesthetic, symbolic and distinctional values. They concurred that the new robes were much better than the current ones.

A Study on the Thermal Bridge Reduced Stiffeners for the Reduction of Window Overall Hear Transfer Coefficient (창문 열관류율 저감을 위한 열교 저감형 보강재 연구)

  • Jang, Hyok-Soo;Kim, Young-Il;Chung, Kwang-Seop
    • Journal of Energy Engineering
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    • v.24 no.4
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    • pp.71-80
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    • 2015
  • Steel stiffener is required for reinforcing the structure of the window frame made of versatile but weak PVC material. Steel stiffener however becomes a source of greater heat loss and frequently plays a role of thermal bridge due to its high thermal conductivity. To maintain thermal resistance similar to PVC frame, steel stiffener is perforated to reduce the effective heat transfer area. To compensate the structural strength of the steel stiffener which is weakened by the perforation, the thickness is increased. Increase in thickness will also increase the thermal heat resistance. Five samples which are PVC frame, PVC frame + original steel stiffener, PVC frame + 30% perforated steel stiffener, PVC frame + 50% perforated steel stiffener, PVC frame + 65% perforated steel stiffener are modeled and simulated for 2nd moment of area and thermal resistance. Therm/window version 6.3 is used for thermal analysis. The results show that among the five samples analyzed, PVC frame + 65% perforated steel stiffener best satisfies both structural strength and thermal resistance.

Characterization of the Microstructure and the Wear Resistance of the Flame-Quenched Cu-8.8Al-4.5Ni-4.5Fe Alloy (화염급냉 표면처리된 Cu-8.8Al-4.5Ni-4.5Fe 합금의 미세구조 분석 및 내마모성에 관한 연구)

  • Lee, M.K.;Hong, S.M.;Kim, G.H.;Kim, K.H.;Kim, W.W.
    • Journal of the Korean Society for Heat Treatment
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    • v.17 no.6
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    • pp.346-355
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    • 2004
  • The flame quenching process has been employed to modify the surfaces of commercial marine propeller material, aluminum bronze alloy (Cu-8.8Al-5Ni-5Fe), and the microstructure, hardness and wear properties of the flame-quenched layers have been studied. The thermal history was accurately monitored during the process with respect to both the designed maximum surface temperature and holding time. The XRD and EDX analyses have shown that at temperatures above $T_{\beta}$, the microstructure consisting of ${\alpha}+{\kappa}$ phases changed into the ${\alpha}+{\beta}^{\prime}$ martensite due to an eutectoid reaction of ${\alpha}+{\kappa}{\rightarrow}{\beta}$ and a martensitic transformation of ${\beta}{\rightarrow}{\beta}^{\prime}$. The ${\beta}^{\prime}$ martensite phase formed showed a face-centered cubic (FCC) crystal structure with the typical twinned structure. The hardness of the flame-quenched layer having the ${\alpha}+{\beta}^{\prime}$ structure was similar to that of the ${\alpha}+{\kappa}$ structure and depended sensitively on the size and distribution of hard ${\kappa}$ and ${\beta}^{\prime}$ phases with depth from the surface. As a result of the sliding wear test, the wear resistance of the flame-quenched layer was markedly enhanced with the formation of the ${\beta}^{\prime}$ martensite.