• 제목/요약/키워드: W/B ratio

검색결과 1,061건 처리시간 0.026초

한국 호박의 지방산 조성 (Fatty Acid Composition of Korean Pumpkins)

  • 남현근;고대희
    • 한국식품영양학회지
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    • 제7권2호
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    • pp.95-99
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    • 1994
  • In order to investigate the fatty acid composition of Korean pumpkins, this study was designed. Three samples of Korean pumpkins, A(yellowish ripe), B(unripe, 30 days old) and C(unripe, 20 days old) were used for fatty acid analysis by gas chromatography. The results were as follows : Pumkin C, B and A showed 10, 12 and 15 kinds of fatty acids, respectively. In case of palmitic acid(C16:0), pumpkin C, B and A showed 22.5%, 22.9% and 26.6%, respectively. In case of u linolenic acid(C18:3), pumpkin C, B and A showed 22.6%, 23.6% and 44.8%, respectively. In case of palmitoleic acid(Cl6:1), pumpkin C. B and A showed 12.4%, 10.1% and 0.5%, respectively. In case of oleic acid(C18:1), pumpkin C. B and A showed 9.2%, 7.7% and 2.8%, respectively, In case of stearic acid(C18:0), pumpkin C, B and A showed B.S%, 3.7% and 3.5%, respectively. The ratio of P/S was 1.4, 1.6 and 1.9 for sample C, B and A, respectively. The ratio of w-3/w-6 was 1.1, 0.9 and 2.6 for sample C, B and A, respectively. Through this study, the ripe pumpkin(sample A) was thought to be good enough in nutritional aspects of fatty acids, particularly a-linoleic acid, Cl8 : 3(u-3) series.

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석쇠석분을 사용한 초유동 콘크리트의 유동특성에 관한 연구 (The Flowing Properties of the Super Flowing Concrete using Limestone)

  • 이상수;권영호;안재현;김무한;박칠림
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.369-374
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    • 1997
  • This study is the experimental results on the flowing properties of the super flowing concrete (SFC) using limestone (LS), which is to develop the SFC in level of ordinary strength. And this study is described with respect to basic concept, confined water ratio ($\beta_p$) of binder (cement+limestone) in paste, relationship between volume ratio of water-binder (w/b) and addition ratio of superplasticizer in mortar, flowing velocity and funneling time and compressive strength in concrete to replacement ratio of LS. The results of this study is improved to flowing properties in fleshly concrete with increasing replacement ratio of LS. The optimal mixing condition of the SFC using LS in level of ordinary strength is proved W/C 55%, LS 40% and W/C 60%, LS 50%.

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Edge-preserving demosaicing method for digital cameras with Bayer-like W-RGB color filter array

  • Park, Jongjoo;Chong, Jongwha
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권3호
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    • pp.1011-1025
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    • 2014
  • A demosaicing method for a Bayer-like W-RGB color filter array (CFA) is proposed. When reproducing images from a W-RGB CFA, conventional color separation methods for W-RGB CFA are likely to cause blurring near the edges due to rough averaging using a color ratio of neighboring pixels. Moreover, these methods cannot be applied to real-life digital cameras with W-RGB CFA because the methods were proposed under an ideal situation, W=R+G+B, not a real-life situation, $W{\neq}R+G+B$. To improve edge performance, we propose a method of constant color difference assumption with inversed weight, which uses information from all edge directions for interpolating all missing color channels. The proposed method calculates the correlation between W, R, G, and B to enable its application to real-life digital cameras with W-RGB CFA. Simulations were performed to evaluate the proposed method using images captured from a real-life digital camera with W-RGB CFA. Simulation results shows that we can demosaic by using the proposed algorithm compared with the conventional one in about +34.79% SNR, +11.43% PSNR, +1.54% SSIM and 14.02% S-CIELAB error. Thus, the proposed method demosaics better than the conventional methods.

H대학교 아음속 풍동 개념설계 (Concept Design of a H.A.U.'s Subsonic Wind Tunnel)

  • 장조원;전창수;김문상;이열;문희장;송병흠;김학봉
    • 한국항공운항학회지
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    • 제13권4호
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    • pp.92-99
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    • 2005
  • A closed-circuit type wind tunnel is designed, which has a test section with the dimensions $1.2(W){\times}1.2(H){\times}3.4(L)$. A subsonic wind tunnel is designed to improves educational circumstances and promote ground tests. It is constituted of an exchangeable test section, first and second diffusers, a fan, a settling chamber, a contraction, and 4 corners. The maximum velocity in the test section is 70m/s and the contraction ratio is 6.25:1. Input power in the wind tunnel is about 96.1 kw (128.8 hp) and its energy ratio is 3.89. It has the dimension of about $7.4(W){\times}3.6(H){\times}21.7m(L)$. The wind tunnel designed in this investigation will be an effective educational and investigational equipment.

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화장품에서 UV 차단제의 피부 자극성과 SPF 측정 (SPF Measurement and Cytotoxicity of Sunscreen Agents in Cosmetic)

  • 김인영;강삼우
    • 분석과학
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    • 제11권2호
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    • pp.79-87
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    • 1998
  • 최근의 소비자들은 waterproof 기능을 가진 광범위한 UV 차단 제품을 선호하며, 피부 안전성에도 많은 관심을 가지고 있다. NR method로 세포 자극성(in-vitro)을 실험한 결과, UV-B의 자외선 차단제들은 0.08 w/v% 이상에서 세포의 생존율이 떨어졌고, UV-A의 자외선 차단제들은 0.06 w/v% 이상에서 세포의 생존율이 떨어졌다. 무기 자외선 차단제들의 patch-test는 각각 10.5와 11.25 이하로 피부에 자극성은 없었다. UV 흡수 곡선, UV-B는 octyl methoxycinnamate(OMC), UV-A는 butyl methoxy dibenzoylmethane(BMDM) 가장 적합하였다. 따라서, 유기 자외선 차단제는 OMC와 BMDM이 nylon과 polyethylene에 코팅된 원료인 $Nylonpoly^{TM}$ UVA/UVB을 사용하였다. 무기 자외선 차단제는 zinc oxide(ZnO)와 titanium dioxide($TiO_2$)를 사용하였다. ZnO와 $TiO_2$의 혼합 비율은 6:4가 적당하였다. 총 UV차단제의 함량은 ZnO 6%, $TiO_2$ 4%와 $Nylonpoly^{TM}$ UVA/UVB 5%를 썬 스크린 크림에 혼합하였다. In-vi-tro의 SPF값은 38.9이었다. 응용으로, 동일 함량을 넣은 O/W type과 W/S type의 썬 스크린 크림을 만들어 시간 경과에 따른 SPF를 측정한 결과, SPF가 O/W type보다 W/S type이 5배 이상 오래 지속되었다. 이것은 해수욕, 등산, 스키를 탈 경우에 효과적이다. 본 연구는 자외선 차단제의 피부 트러블을 최소화하고자 하였으며, 매끄러움성, 피부 안전성과 자외선 차단 효과가 우수한 화장품이라고 생각되어진다.

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고강도 콘크리트의 자기수축 특성에 관한 연구 (A Study on Characteristic of Autogenous Shrinkage of High Strength Concrete)

  • 이영재
    • 한국산업융합학회 논문집
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    • 제16권1호
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    • pp.1-8
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    • 2013
  • In case that W/B is 20%, 30%, 40% respectively, the effects of additive and shrinkage reducing agent on the autogenous shrinkage for high strengthen concrete through the substitution of FA and SF analysis were obtained as following conclusions. When the ratio of FA increased, the compressive strength of high strengthen concrete is decreased in the early times. As the ratio of SF increase, the compressive strength also increased. Comparing with PC(Portland Cement) for 7 days curing, the strength is 13.8% of FA10 + SR0.5 and 19.2% of FA15 + SR0.5 decreased when W/B is 20%, and 6.1% of SF7.5 + SR0.5, 4.8% of SF15 + SR0.5, the strength are increased. In case that W/B is 30%, 13.1% of FA10 + SR0.5 19.1% of FA15 + SR0.5 the strength is decreased and 4.1% of SF 7.5 + SR0.5, 7.2% of SF15 + SR0.5 the strength are increased. In case of W/B 40%, 4.3% of FA10 + SR0.5, and 8.7% of FA15 + SR0.5, the strength is decreased and 3.3% of SF7.5 + SR0.5, 6.3% SF15 + SR0.5 the strength is increased. When the ratio of SR is 0.5%, autogenous shrinkage strain of OPC concrete appeared $-417{\times}10-6$ in 56days curing, the shrinkage strain is decreased 23.7%. The reducing effects of autogenous shrinkage when the mineral and shrinkage agent are used are the same as ones when only shrinkage agent used.

리빙 콘크리트 패널용 마그네시아 복합체의 마그네시아 및 인산칼륨 비율에 따른 기초 품질 특성 (The Quality Properties According to the Ratio of Magnesia and Potassium Phosphate of Magnesia Composites for Living Concrete Panel)

  • 최연왕;남은준;김철규;양능원
    • 한국건설순환자원학회논문집
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    • 제9권4호
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    • pp.617-624
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    • 2021
  • 본 연구에서는 리빙 콘크리트 패널 설계시, 재료적 측면에서 모재료의 품질을 제어하기 위하여 마그네시아 복합체의 마그네시아 및 인산칼륨 비율에 따른 품질특성을 평가하였다. 품질특성은 W/B는 7수준(30, 35, 40, 45, 50, 55 및 60%), P:M 4수준(1:0.5, 1:1.0, 1:2.0 및 1:3.0 vol. %)에 따라 제조하여 평가하였다. 마그네시아 복합체의 플로우 평가결과, W/B가 증가할수록 플로우가 증가하는 경향이 나타났으며, P:M 증가에 따라 플로우가 감소하는 경향이 나타났다. 마그네시아 복합체의 압축강도 평가결과, P:M이 증가함에 따라 강도가 감소하는 경향이 나타났으나 최적의 배합비율이 존재함을 확인할 수 있었다.

급속 보수용 마그네슘 인산염 모르타르의 경화 및 강도특성 (A Hardening and Strength Properties of Magnesium Phosphate Mortars for Rapid Repair Materials)

  • 오홍섭;이인희
    • 한국구조물진단유지관리공학회 논문집
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    • 제23권3호
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    • pp.103-110
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    • 2019
  • 다양한 원인에 의한 포장체에 손상이 발생하면 신속한 통행재개를 위한 급속보수가 필요하게 된다. 산화마그네슘인산염복합체의는 경화시간이 짧고, 조기 강도발현이 가능하여 급속보수재료로 적합한 특성을 갖고 있다. 연구에서는 경소마그네시아와 제1인산칼륨을 결합하여 보수재료로 개발하기 위하여 물-결합재(W/B)비, 마그네슘-인산염(M/P)비 등의 배합비를 조정하면서 경화와 강도특성을 평가하고자 하였다. 그리고 현장 적용시의 작업성을 확보하기 위하여 표준사와 일반모래에 따른 거동차이와 지연제별 특성을 평가하였다. 실험결과 물-결합재비는 35%내외와 마그네슘-인산염비는 1.0~1.2 내외가 강도측면에서 가장 적합한 것으로 분석되었다. W/B비 0.35, M/P비 1.2 변수에서 1일 강도 25.0MPa 이상 발현되어 조기 보수재료로서 활용가능성이 충분한 것으로 분석되었다. 작업시간 확보를 위해서는 붕산을 지연제로 사용하는 것이 적합한 것으로 나타났으며, 산화마그네슘의 순도는 90~95%내외가 경화시간 확보를 위해 효과적인 것으로 나타났다.

Light-susceptibility of Camptothecin Production from in Vitro Cultures of Camptotheca acuminata Decne

  • Park, Young-Goo;Park, Mee-Hee;Yang, Jae-Kyung;Chung, Young-Gwan;Park, Myung-Suk
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제8권1호
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    • pp.32-36
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    • 2003
  • Production of camptothecin ((PT) from callus cultures of Camptotheca acuminata Decne was affected by light and culture conditions. Among the culture media tested, modified B5 medium containing 3% (w/v) sucrose, 2 mg/L B,4-D, 2 times of MS medium vitamins, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.05% (w/v) activated charcoal, and 0.15% (w/v) gelite was used for callus induction . The highest cell growth and CPT production were obtained in dark and green light condition, respectively. Photoperiod has no effect on cell growth and CPT production. Both cell growth and CPT production were also influenced by combination ratio of red and blue light .Cell growth and CPT production were the highest in the ratio of red and blue light,90:10.

혼합 작동 유체를 이용한 진동 세관형 히트 파이프의 압력 진동과 열전달 특성에 관한 연구 (The Study on Pressure Oscillation and Heat Transfer Characteristics of Oscillating Capillary Tube Heat Pipe Using Mixed Working Fluid)

  • 정현석;김정훈;김주원;김종수
    • 대한기계학회논문집B
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    • 제26권2호
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    • pp.318-327
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    • 2002
  • In this paper, heat transfer and pressure oscillation characteristics on oscillating capillary tube heat pipe(OCHP) according to input heat flux, mixture ratio of working fluid and inclination angle were investigated and were compared single working fluid(R-142b) with binary mixture working fluid(R-142b-Ethano1). OCHP was made to serpentine structure of loop type with 10 turns by drilling the channels of length 220mm, width 1.5mm, and depth 1.5mm on the surface of brass plate. In this study, R-l42b and R-l42b-Ethanol were used as working fluids, the charging ratio of working fluids was 40(vol.%), the input heat flux to evaporating section was changed from 0.3W/㎠ to 1.8W/㎠, and mixture ratio of working fluid was R(100%), R(95%)-E(5%), R(90%)-E(10%), and R(85%)-E(15%). From the experimental results, it was found that the effective thermal conductivity of single working fluid was better than that of binary mixture working fluid. But, in case of binary mixture working fluid, critical heat flux was higher than that of single working fluid. And, the higher the mixture ratios of working fluid, the lower heat transfer performance. In case of pressure oscillation, as the inclination angle was lower, pressure wave was more irregular. These phenomena were more serious when the working fluid was binary mixture. Besides, when mixture ratio was higher, saturated pressure was increased, more irregular wave was observed and the mean amplitude was increased. For the same input heat flux, inclination angle and charging ratio, when pressure oscillation has sinusoidal wave, mean amplitude was small, and saturated pressure was low value, the heat transfer was excellent.