• Title/Summary/Keyword: $\delta^{13}C$

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Optimization of Vacuum Drying Conditions for a Steamed (Pumpkin-) Sweet Potato Slab by Response Surface Methodology (반응표면분석법을 이용한 증절간 (호박)고구마의 최적 진공건조조건 설정)

  • Shin, Mi-Young;Youn, Kwang-Sup;Lee, Su-Won;Moon, Hye-Kyung;Lee, Won-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.9
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    • pp.1314-1320
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    • 2011
  • Vacuum drying was conducted for a steamed pumpkin-sweet potato slab to improve its quality, convenience and preference as snack. Steamed sweet potato was dried from 30 to $60^{\circ}C$ for 12 hr, after which moisture contents, colors, and taste were evaluated. The lowest moisture content was 0.22% upon vacuum drying at $60^{\circ}C$ for 12 hr. Lightness decreased while other color values (a, b and ${\Delta}E$) increased with increasing drying temperature and drying time. Reducing sugar and soluble solid contents ranged from 98.7~268.11 mg/g and $19{\sim}72^{\circ}Brix$, respectively. Sensory score of the sample was the highest when dried at $50^{\circ}C$ for 6 hr. The optimum drying conditions were predicted to be $48.5{\sim}62^{\circ}C$ and 5.1~7.1 hr by response surface methodology.

A Study on the Content of General Compounds, Amino Acid, Vitamins, Catechins, Alkaloids in Green, Oolong and Black Tea (녹차, 우롱차 및 홍차의 일반성분, 아미노산, 비타민류, 카테킨류 및 알카로이드류의 성분분석에 관한 연구)

  • 이영자;안명수;홍기형
    • Journal of Food Hygiene and Safety
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    • v.13 no.4
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    • pp.377-382
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    • 1998
  • This study was carried out to measure the contents of moisture, crude ash, crude fat, total amino acid, with amino acid composition, vitamin C, ${\beta}-carotene$, vitamin E, total catechins, EGCG, EGC, ECG, EC, GA, caffeine, theobromine and theophylline of the green tea I, II, III, oolong, and black tea. The content of crude fat of green tea I, II, III, oolong, and black teas was 1.1, 2.5, 4.9, 0.8 and 1.2% respectively, total amino acid content was 0.87, 0.78, 0.60, 0.63 and 1.05% respectively, and theanine content was 0.52, 0.48, 0.31, 0.41 and 0.61%, respectively. Total amino acid content of green tea increased in the order of green tea I> green tea II> green tea III, and among the teas, the content of theanine was the highest in the amino acids present. The content of vitamin C of green teal, II, III, oolong, and black tea was 101.6, 87.5, 95.9, 99.1 and 108.0 mg%, respectively, ${\beta}-carotene$ content was 270, 268, 481, 80 and 181 ppm, respectively. Among the ${\alpha}-,\;{\beta}-,\;{\gamma}-\;and\;{\delta}-tocopherol$, the content of ${\alpha}-tocopherol$ was the highest in vitamin E present, and ${\beta}-\;and\;{\delta}-tocopherol$ were not detected in the samples of green teal, II, III, oolong, and black teas. The total catechins of green teal, II, III, oolong, and black teas was 10.5, 10.4, 7.2, 8.4 and 1.8% respectively, and among them, EGCG content was the highest. The content of EGC increased in the order of green tea I > green tea III > green tea II > oolong tea> black tea. The contents EGCG and ECG increased in the order of oolong tea> green tea I > green tea II> green tea III> black tea, and the highest contents of EGCG and ECG were observed in the samples of oolong tea. The content of GA was 0.01, 0.02, 0.05, 0.13 and 0.31%, respectively, and the highest contents of GA, caffeine and theobromine were observed in the sample of black tea. The highest content of theophylline, however, was observed in the sample of green tea I.

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Distributions of Hyperfine Parameters in Amorphous $Fe_{83}B_9Nb_7Cu_1$ Alloys (비정질 $Fe_{83}B_9Nb_7Cu_1$의 M$\)

  • 윤성현;김성백;김철성
    • Journal of the Korean Magnetics Society
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    • v.9 no.6
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    • pp.271-277
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    • 1999
  • Amorphous $Fe_{83}B_9Nb_7Cu_1$ alloy has been studied by M$\"{o}$ssbauer spectroscopy. Revised Vincze method was used and distributions of hyperfine field, isomer shift, and quadrupole line broadening of the sample at various temperatures have been evaluated and Curie temperature and $H_{hf}\;(0)$ were calculated to be 393 K and 231 kOe, respectively. Temperature variation of reduced average hyperfine field shows a flattered curvein comparison with the Brillouin curve for S=1. This behavior can be explained on the basis of Handrich molecular field model, in which the parameter Δ, which is a measure of fluctuation in exchange interactions, is assumed to have the temperature dependence ${Delta}=0.75-0.64{\tau}+0.47{\tau}^2$ where $\tau$ is $T/T_C$. At low temperature, the average hyperfine field can be fitted to $H_{hf}\;(T)=H_{hf}\;(0)\;[1-0.44\;(T/T_C)^{3/2}-0.28(T/T_C)^{5/2}-… ]$, which indicates the presence long wave length spin wave excitations. At temperature near TC, reduced average hyperfine field varies as $1.00\;[1-T/T_C]^{0.39}$. It is also found that half-width of the hyperfine field distribution was 102 kOe (3.29 mm/s) at 13 K and decreased monotonically as temperature increased. Above the Curie temperature, an average quadrupole splitting value of 0.43 mm/s was found. Average line broadening due to quadrupole splitting distribution was 0.31 mm/s at 13 K and decreases monotonically to 0.23 mm/s at 320 K, whereas that due to the isomer shift distribution is 0.1 mm/s at 13 K and 0.072 mm/s at 320 K, which is much smaller than that of both hyperfine field and quadrupole splitting. The temperature dependence of the isomer shift can be fitted within the harmonic approximation to a Deybe model with a Debye temperature ${Theta}_D=424{\pm}5K$.TEX>.

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Investigation of Characterization and Fabrication High-Temperature Superconducting Multiplexer by Pulse laser Deposition (레이저 공정을 이용한 고온초전도 멀티플렉서의 제작과 특성 분석)

  • Kim, Cheol-Su;Song, Seok-Chun;Lee, Sang-Yeol
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1858-1860
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    • 1999
  • To fabricate superconducting multiplexers with narrow pass band characteristics and reduce the physical size of device, we have designed multiplexer using hair-pin type filters with the center frequency of 13.6 GHz. Multiplexers have been fabricated superconductor(HTS), because It has low surface resistance. The $YBa_2Cu_3O_{7-{\delta}}$(YBCO) films were deposited on MgO substrates$(20{\times}20{\times}0.5mm^3)$ by using pulsed laser deposition and conventional photo-lithographic methods were used to pattern the multiplexer. Epitaxial YBCO films were grown on(100) MgO substrates and showed strongly c_axis orientations observed by X-ray diffraction technique. Superconducting transition temperatures were measured to be about 89K. Simulated results of superconducting multiplexer consisting of hair-pin type filters show the insertion loss of about 1.2dB. The measured frequency response will be compared with the simulated results.

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AERODYNAMIC ANALYSIS OF SUB-ORBITAL RE-ENTRY VEHICLE (저궤도 재진입 비행체의 공력해석)

  • Kim, C.W.;Lee, Y.G.;Lee, D.S.
    • Journal of computational fluids engineering
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    • v.13 no.2
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    • pp.1-7
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    • 2008
  • For Aerodynamic analysis of vehicle at altitude, 100km, the validity of governing equations based on continuum model, was reviewed. Also, as the preliminary study for the sub-orbital space plane development, a candidate geometry was suggested and computational fluid dynamic(CFD) analysis was performed for various angles of attack in subsonic and supersonic flow regimes to analyze the aerodynamic characteristics and performance. The inviscid flow analyses showed that the stall starts at angle of attack above $20^{\circ}$, the maximum drag is generated at angle of attack, $87^{\circ}$ and the maximum lift to drag ratio is about 8 in subsonic flow. In supersonic, the stall angle is about $40^{\circ}$ and the maximum drag is generated at angle of attack, $90^{\circ}$. Also, mach number distribution of re-entry vehicle was computed versus altitudes.

Coloration of Synthetic fiber fabrics with Loess(I) (합성섬유 직물에 대한 황토염색(I))

  • Lee, Jeon-Sook;Choi, Kyung-Eun
    • Korean Journal of Human Ecology
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    • v.8 no.1
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    • pp.19-24
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    • 2005
  • This paper is to know the possibility of coloration of synthetic fibers with loess. Fabrics woven with polyester, nylon, and acrylic fibers were dyed by a dip-pad operation with a laboratory mangle. Drying, curing at 180$^{\circ}C$ for 10 minutes and washing were followed. Effect of curing after drying were investigated in terms of K/S values and SEM microphotographes. Reddish-yellow(a:75.13, B:15.14, ${\Delta}$E:45.31) colored fabric ascertain possibility of coloration of synthetic fibers with loess. Acrylic fiber shows highest dye uptake of the three kinds of fibers and fastness increases by curing after drying.

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OBSERVATIONS OF THE J=1-0 TRANSITION LINE OF HCN IN COMET HALE-BOPP (헤일밥 혜성의 HCN(J=1-0) 천이선 관측)

  • KIM BONG GYE;KIM HYO RYUNG;CHO SE HYUNG;KIM SANG JOON
    • Publications of The Korean Astronomical Society
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    • v.13 no.1 s.14
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    • pp.129-134
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    • 1998
  • Observations of the J=1-0 transition line of HCN were made at the center of Comet C/1995 O1 (Hale-Bopp) from November, 1996 to April, 1997 with the 14-m radio telescope at the TRAO (Taeduk Radio Astronomical Observatory). From the obtained data, an HCN production rate at each observed date was derived. The rapid variation of the HCN production rate near the perihelion was detected, and it is thought to be caused by jet(s) from the nucleus. The correlation between the visual magnitude and the HCN production rate is found to be $Q_{HCN}=27.03-0.11(m_v-5log{\Delta})$.

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Data processing technique for data measured in MO image measurement system

  • Lee, Wongi;Lee, Hyoyeon;Yoo, Jaeun;Youm, Dojun
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.1
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    • pp.25-28
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    • 2013
  • We report processing technique in the MO image measurement system. Calibration procedure is not only considered to perpendicular field but also in-plane field. Current density and field profiles are obtained by Biot-savart law and inversion method. We show example of $(Gd,Y)_1Ba_2Cu_3O_{7-{\delta}}-BaZrO_3$ film that have tilted nano rod pinning centers about $13^{\circ}$ from the c-axis.

A Study of Onion Skin Pigments in the Extracting Solvents and Residual Pigments after Dyeing the Textiles

  • Bae, Soon-Ei
    • Journal of Fashion Business
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    • v.13 no.3
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    • pp.109-117
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    • 2009
  • To set up the outstanding and scientific dyeing method in making the condensed liquid of pigment obtained from onion skins and the improved reliability, the following basic experiments were performed. The pigment was extracted in the distilled water at $70^{\circ}C$ and methanol at room temperature and then it was analyzed with LC/MS/MS system (Liquid Chomatography/Mass Spectroscopy/Mass Spectroscophy, LIQ Advantage Max, Thermo Finnigan, USA) for its pigmental characteristics. The unrefined silk and refined silk were dyed by making use of the derived pigment in such a way. The chromameter (CR-200, Minolta, Japan) was used to measure the change in surface color in textiles to be dyed by the extracting condition and the color difference ${\Delta}E$ was determined according to the color difference formula CIE LAB through measuring the psychometric lightness L* and chromaticity coordinates a* and b*.

Studies on Chemical Components of Cephalotaxus koreana Nakai (개비자나무 Cephalotaxus koreana Nakai 잎의 성분 연구 (I))

  • 육창수;정진환;이종일
    • Korean Journal of Plant Resources
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    • v.13 no.2
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    • pp.89-94
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    • 2000
  • Cephalotaxus koreana Nakai is endemic species of Korea. Since old days, the fruits have been used as a parasiticide and leaves have been used for a pierced wound by insects. The essential oil components from its aerial parts and stem bark by steam distillation were investigated. Several compounds were characterized by GC-Mass spectra. It was found that the leaves, stembark and flowers contain the compounds of essential oils, 1-octene-3-ol, hexadecanoic acid; $\alpha$-pinene, $\Delta^3$-carene mainly, linalylacetate, $\beta$-cubebene, 3,4-octadine-7-methyl , ferruginol(stem bark) and $\alpha$-pinene mainly, $\beta$-pinene , cyclopropane-1,1-dimethyl-2-(3-methyl-1,3-butadienyl), etc. This Cephalotaxus spp. contains the first components of ferruginol(M.W.286.03, $C_{20}H_{30}O)$ which belong to diterpene.

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