• Title/Summary/Keyword: Humidity stability

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Improving the Surface Functionality of Curdlan by Conjugation with Unfolding Protein through Naturally Occurring Maillard Reaction

  • Nakamura, Soichiro;Ogawa, Masahiro;Saeki, Hiroki;Saito, Masayoshi;Miyasaka, Satoko;Hata, Junya;Adachi, Naoko;Hwang, Jae-Kwan
    • Preventive Nutrition and Food Science
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    • v.5 no.4
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    • pp.200-204
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    • 2000
  • Protein conjugation of curdlan belonging to $\beta$-1, 3-glucan was carried out to improve it surface functionalities. The glucan was mixed with phosvitin, {TEX}$$\alpha$_{s}${/TEX}-casein, lysozyme or ovalbumin, respectively. The mixture was freeze-dried, and he resulting powder was incubated at 6$0^{\circ}C$ and 79% relative humidity for 12 days in order to generate a controlled Maillard reaction between curdlan and proteins. conjugation with unfolding proteins, i.e., phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein, drastically increased the solubility of the glucan, whereas lysozyme and ovalbmin did not. The solubility in water of curdlan was 3.44% for the phosvitin conjugate and 1.09% for the {TEX}$$\alpha$_{s}${/TEX}-casein conjugate. SDS-slab polyacrylamide gel electrophoresis showed that curdlan was solubilized due to covalent binding with phosvitin. Emulsifying properties of curdlan were substantially improved by the conjugation with phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein. Emulsion stability of the curdlan-phosvitin conjugate was about 2.9 times greater than that of the curdlan-phosvitin mixture.

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A Fundamental Study for Development on Waterproof and Flame Retardant processing technology the Interior Wood of using Induced electricity heating Microwave (유전가열 마이크로파를 적용한 방수·방염 내장목재 개발을 위한 기초적 연구)

  • Park, Cheul-Woo;Heo, Jae-Won;Lim, Nam-Gi
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.05a
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    • pp.35-41
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    • 2008
  • Qualitative enhancement of dwelling life has changing the recognition for the environment friendly wood which is being highlighted for its usage as an interior materials. This trend may prove the excellent performance of wood whose inherent characteristics has its comfortable, mild feeling of material, sound resistance and stabilities and the market of interior woods including floor, moulding and wooden panel as finishing interior materials is growing sustainably. However, since this materials is vulnerable to humidity and flame, waterproofing and flame retarding stability, an essential condition for interior materials, together with maintenance, are the main topics to be resolved. From the above-mentioned results, as a result of waterdrop contact angle, wood absorption volume and water content percentage test and the performance test of the processed materials after flame retardant, though there was some submerging time changes among types of woods for ensuring waterproofing performance improvement but as time passes, similar tendency was noticed to be formulated. As the submerging time is increased, so does the absorption volume and accordingly optimal level of range is judged to be drawn in order to ensure excellent performance, taking optimal economy into consideration. Therefore, it is considered that above-mentioned woods could be utilized for waterproof and flame retardant processed interior materials using uniform microwave and in order to put this technology into practical application, a research by way of diversified performance proving is required to be carried out.

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Micro Structure and Surface Characteristics of NiCr Thin films Prepared by DC Magnetron Sputter according to Annealing Conditions (DC 마그네트론 스퍼터링 NiCr 박막의 열처리 조건에 따른 미세구조 및 표면특성)

  • Kwon, Yong;Kim, Nam-Hoon;Choi, Dong-You;Lee, Woo-Sun;Seo, Yong-Jin;Park, Jin-Seong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.6
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    • pp.554-559
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    • 2005
  • Ni/Cr thin film is very interesting material as thin film resistors, filaments, and humidity sensors because their relatively large resistivity, more resistant to oxidation and a low temperature coefficient of resistance (TCR). These interesting properties of Ni/Cr thin films are dependent upon the preparation conditions including the deposition environment and subsequent annealing treatments. Ni/Cr thin films of 250 nm were deposited by DC magnetron sputtering on $Al_2O_3/Si$ substrate with 2-inch Ni/Cr (80/20) alloy target at room temperature for 45 minutes. Annealing treatments were performed at $400^{\circ}C,\;500^{\circ}C,\;and\;600^{\circ}C$ for 6 hours in air or $H_2$ ambient, respectively. The clear crystal boundaries without crystal growth and the densification were accomplished when the pores were disappeared in air ambient. Most of surface was oxidic including NiO, $Ni_2O_3$ and $Cr_xO_y$(x=1,2, y=2,3) after annealing in air ambient. The crystal growth in $H_2$ ambient was formed and stabilized by combination with each other due to the suppression of oxidized substance on film surface. Most oxidic Ni was restored when the oxidic Cr was present due to its stability in high-temperature $H_2$ ambient.

The Effect of Disintegrants on the Properties of Salicylamide Tablets (수종의 붕해제가 살리실아미드정제의 제제특성에 미치는 영향)

  • Hwang, Sung-Joo;Rhee, Gye-Ju;Jee, Ung-Kil;Kwak, Hyo-Sung;Kim, Chong-Kook
    • Journal of Pharmaceutical Investigation
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    • v.22 no.1
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    • pp.41-48
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    • 1992
  • Six common tablet disintegrants (corn starch, Avicel PH102, calcium carboxymethylcellulose, Primojel, Kollidon CL and Ac-Di-Sol) were used at the concentration of 0, 2, 4 and 6% (w/w) in salicylamide tablets made with wet granulation method. Certain physical parameters of the disintegrants (moisture sorption, hydration capacity and bulk density) were determined to evaluate their relative efficiency. The disintegration time and dissolution rate of the tablets were correlated well with the ranks of initial rate of moisture sorption for each disintegrant as follows; Ac-Di-Sol, Kollidon CL, primojel, calcium CMC, corn starch and Avicel PH102. The initial rate of moisture sorption was important for the disintegration capacity as well as hydration capacity. The effect of storage at different temperatures and relative humidity upon the tablets containing various disintegrants was evaluated in terms of tablet hardness and disintegration time. Storage at high temperature reduced the hardness substantially and retarded the disintegration of the all tablets studied. Especially, the hardness of tablets containing Kollidon CL was significantly reduced. Although the tablet hardness was decreased and the disintegration time was increased under a moderate humid condition, both of them were decreased under the severely high humid condition of 80 or 90% RH, which was due to the breakrupture of tablet matrix bonds by the excessive uptake of moisture. Therefore, the stability caused by moisture sorption should be considered, when disintegrants having high moisture sorption such as Kollidon CL, Ac-Di-Sol and Primojel were employed in the tablets containing water-labile or hygroscopic drugs.

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Study on the Material Characteristic of Baekeuikwaneum (the White-Robed Buddhist Goddess of Mercy) Wall-Painting of Bogwangmyungjun in Wibongsa, Wanju (완주 위봉사보광명전 백의관음벽화의 재료학적 특성 연구)

  • Kim, Young Sun;Lee, Sang Jin;Choi, In Sook;Jin, Byung Hyuk;Lee, Hwa Soo
    • Journal of Conservation Science
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    • v.30 no.1
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    • pp.55-65
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    • 2014
  • On this studyed, the Wibongsa BoGwangMyungJun BaekEuiKwanEum wall-painting was conservation of Scientific research ahead. This study carried out Grain size analysis, SEM-EDS, XRD, P-XRF, FT-IR and ultrasonic exploration for wall-painting. As a result, walls layer used to mineral particles size was mixing the medium-texture and fine texture. painting layers pigments used to base paintings was ocher, white pigments was hobun, red pigments was suckganju, green pigments was suckruk. Also BackuiKannon wall-painting walls damage reason of that was long-term physical shocks. painting layers damage was include detachment or powders. it is affected by temperature and humidity. Therefore in the future conservation of wall-paintings through scientific analysis based on such data, conservation processing is performed through the preservation and enhance the stability of the paintings as a basis for the conservation of management can be utilized.

Habitat and Phytosociological Characters of Ceratopteris thalictroides, Endangered Plant Species on Paddy Field, in Nakdong River (논 잡초 멸종위기식물인 물고사리의 낙동강유역 자생지 최초보고 및 군락분류)

  • Choi, Byoung-Ki;Lee, Chang-Woo;Huh, Man-Kyu
    • Weed & Turfgrass Science
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    • v.3 no.1
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    • pp.50-55
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    • 2014
  • This study is aimed at classifying the syntaxa of Ceratopteris thalictroides dominant community on the Nakdong River, and to collect basic data for research of habitat. The communities were carried out by using the Z.-M. School's method and numerical classification technique. The result of syntaxa was classified three communities such as Persicaria japonica-Ceratopteris thalictroides community, Lindernia procumbens-Ceratropteris thalictroides community, and Limnophila indica-Ceratopteris thalictroides community. The ordination analysis displayed the vegetation types with respect to complex environmental gradients. After ordination and clustering analysis, the effective humidity, soil stability, trampling effects, anthropogenic effects and flooding frequency were identified as the important factors deciding the vegetation pattern. It was pointed out to establish a long-term ecological site for protecting such vulnerable vegetation against overexploitation and global climate change.

Comport Sensation of Blue Jeans depending on Fiber Contents (청바지의 소재별 쾌적감에 관한 연구)

  • 홍문경;이미식;권계화;전정애
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.2
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    • pp.237-248
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    • 2001
  • The purpose of this study was to compare the comfort sensation depending on four different kinds of denim blue jeans: cotton, cotton/tencel, tencel, cotton/pp. The objective and subjective experiments were conducted to measure the comfort of blue jeans. To investigate the objective comfort, physical properties related to thermal insulation, moisture properties and hand were measured. For subjective comfort measurement, 5 healthy female college students were taken as subjects. The outcomes of the experiments are as follows: The higher the air permeability and bulk density of the denim, the lower the thermal insulation, the thicker the denim, the higher the thermal insulation. Tencel blending denim showed the higher bulk density, the lower air contents, and consequently the lower thermal insulation than the other denims. Tencel showed the highest moisture regain, and cotton/tencel blend showed the highest water vapor permeability. Tencel denim had relatively better flexibility, shape stability and elastic recovery than the other denims. The total hand values of the denims by KES-FB system were not significantly different. Cotton and cotton/pp denims raised the subjects body temperature after excercise more than tencel or cotton/tencel denims. Average skin temperature was found to have a correlation with micro climate temperature and micro climate humidity. The correlation coefficients were 0.749 and 0.767, respectively. However, average skin temperatures were not significantly different among the materials. Pulse rate was found to be the highest when wearing cotton/pp and the lowest in case of cotton/tencel denim. The energy was consumed in order of cotton>cotton/pp>tencel>cotton/tencel. There was no significant difference in preference before excercise, but, after the excercise, the order of preference changed as the following; cotton/tencel>tencel>cotton/pp>cotton.

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Physicochemical Properties of Freeze-dried Corn Starch Sponge Matrix (동결 건조된 옥수수 전분 스펀지 매트릭스의 이화학적 특성)

  • Han, Kyung-Hoon;Kim, Doh-Hee;Song, Kwan-Yong;Lee, Kye-Heui;Yoon, Taek-Joon;Yang, Sung-Bum;Lee, Seog-Won
    • The Korean Journal of Food And Nutrition
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    • v.23 no.3
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    • pp.419-427
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    • 2010
  • The focus of the current study was to investigate the physicochemical properties of a corn starch-sponge matrix prepared at a low concentration below gel forming by freeze-drying. The effect of variables(starch concentration, heating temperature, and heating hold time) on the physicochemical properties of the samples was analyzed by response-surface methodology. Regression models on the properties of samples such as hardness, springiness, and water solubility index(WSI) showed high correlation coefficients(r>0.95) and significant F values, but regression models for the other properties(swelling power, apparent viscosity, reducing sugar content, and digestibility) showed them to have relatively low significance. Sample hardness of sample showed the highest value at condition of $90^{\circ}C$ and 5%, whereas springiness was at a maximum at $130^{\circ}C$ and 5%. Also, at 1% of starch concentration, mechanical properties were greatly decreased as the relative humidity increased, compared with the 3% and 5%, especially in the hardness of samples. The WSI showed an increasing trend with heating temperature regardless of starch concentration. Overall, the physicochemical properties of freeze-dried corn starch-sponge matrix were influenced much more by starch concentration and heating temperature than by heating hold time. The results of this study show that the basic properties of freeze-dried corn starch-sponge matrix can be used for the specific food applications or as a functional material for its stability.

Estimation of Surface Layer Heat Flux Using the UHF Sensor Installed on UAV (UHF 센서 탑재 UAV를 이용한 지표층 열 플럭스 산출)

  • Kim, Min-Seong;Kwon, Byung Hyuk;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.1
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    • pp.265-276
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    • 2018
  • Observation and data analysis techniques have been developed for observational blind areas in the lower atmosphere that are difficult to be monitored with fixed equipment on the ground. The vertical data of temperature and relative humidity are remotely collected by the UHF radiosonde installed on UAV and compared with the data measured in the 10 m weather tower. From the validated vertical profile, extrapolated surface temperature and the bulk transfer method were used to estimate the sensible heat flux depending on the atmospheric stability. Compared with the sensible heat flux measured by the 3-dimensional ultrasonic anemometer on the ground, the error of the sensible heat flux estimated was 23% that is less than the range of 30% allowed in the remote sensing. Estimated atmospheric boundary layer height from UAV sensible heat fluxes can provide useful data for air pollution diffusion models in real time and economically.

Development of the SiO2/Nano Ionomer Composite Membrane for the Application of High Temperature PEMFC (전기방사를 이용한 SiO2/nano ionomer 복합 막의 제조 및 고온 PEMFC에의 응용)

  • Na, Hee-Soo;Hwang, Hyung-Kwon;Lee, Chan-Min;Shul, Yong-Gun
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.5
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    • pp.569-578
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    • 2011
  • The $SiO_2$ membranes for polymer electrolyte membrane fuel cell (PEMFC) are preapared by electrospinning method. It leads to high porosity and surface area of membrane to accommodate the proton conducting materials. The composite membrane was prepared by impregnating of Nafion ionomer into the pores of electrospun $SiO_2$ membranes. The $SiO_2$:heteropolyacid (HPA) nano-particles as a inorganic proton conductor were prepared by microemulsion process and the particles are added to the Nafion ionomer. The characterization of the membranes was confirmed by field emission scanning electron microscope (FE-SEM), thermogravimetry analysis (TGA), and single cell performance test for PEMFC. The Nafion impregnated electrospun $SiO_2$ membrane showed good thermal stability, satisfactory mechanical properties and high proton conductivity. The addition of the $SiO_2$:HPA nano-particle improved proton conductivity of the composite membrane, which allow further extension for operation temperature in low humidity environments. The composite membrane exhibited a promising properties for the application in high temperature PEMFC.