• 제목/요약/키워드: P-V value

검색결과 1,083건 처리시간 0.028초

비타민 C 첨가에 따른 미세과육 함유 사과주스의 저장 중 품질변화 (Quality Changes in Pulp-containing Apple Juice upon Addition of Vitamin C)

  • 박난영;김재화;서지형;우상철;정용진
    • 한국식품저장유통학회지
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    • 제17권4호
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    • pp.451-456
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    • 2010
  • 미세과육 함유 사과주스의 비타민 C 첨가에 따른 저장 중의 품질변화를 조사하였다. 비타민 C 첨가 유무에 따라 저장 기간 동안 비타민 C 함량의 차이가 크게 나타났다. 비타민 C 첨가농도에 따른 당도와 산도의 차이는 크게 나타나지 않았으며, pH는 비타민 C 무첨가 구간 4.40에 비해 첨가구간에서 pH 4.30~4.29 수준으로 낮게 나타났다. 색상의 변화는 비타민 C 첨가량이 증가하고 저장기간이 길어질수록 L값과 b값이 감소하였으며, 관능평가에서 taste, 전반적인 기호도에서 비타민 C 0.02%(w/v) 첨가구, 무첨가구 순으로 높게 나타났으며, 이 외에 비타민 C 0.02%(w/v) 첨가구는 color에서, 무첨가구는 flavor에서 가장 높은 기호도를 나타내었다. 저장기간 중 비타민 C 감소의 변화는 저장온도 $4^{\circ}C$에서 저장기간이 길어질수록 비타민 C 함량의 감소가 적게 나타나 저장온도와 비타민 C 함량은 저장기간이 길어질수록 효과가 큰 것으로 나타났다. ASC(alcohol soluble color)의 변화는 비타민 C 첨가량이 많을수록 낮게 나타났으며, $37^{\circ}C$에 비해 $4^{\circ}C$ 저장구간에서 ASC가 낮게 나타나는 경향을 보였다. 이상의 결과, 미세과육 함유 사과주스는 비타민 C를 0.02% 첨가하여 $4^{\circ}C$에서 저장하는 것이 가장 효과적으로 나타났다.

꾸지뽕나무 부위별 추출물의 생리활성 탐색 (Physiological Activities of Extracts from Different Parts of Cudrania tricuspidata)

  • 이혜진;도정룡;권중호;김현구
    • 한국식품영양과학회지
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    • 제40권7호
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    • pp.942-948
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    • 2011
  • 꾸지뽕나무를 잎, 줄기, 열매로 부위별 추출조건에 따른 추출물의 생리활성을 알아보고자 전자공여작용, 총 폴리페놀 함량, SOD 유사활성, tyrosinase 저해 효과, 아질산염 소거작용 및 ACE 저해 활성을 측정하였다. 전자공여능의 경우 추출용매에 따라 70% 에탄올>70% 메탄올>물 추출물순으로 활성을 나타냈으며, 특히 줄기의 70% 에탄올 추출물이 90.20%로 가장 높았다(p<0.05). 이는 비교물질인 Lascorbate의 활성보다 높은 수치였다. 총 폴리페놀 함량 측정 결과 모든 추출조건에서 잎 추출물이 가장 많은 폴리페놀을 함유하고 있었다(p<0.05). 또한 추출용매에 따라 70% 메탄올 추출물들이 폴리페놀을 많이 포함하고 있음을 알 수 있었다. SOD 유사활성은 잎의 물 추출물이 64.54%로 가장 높은 활성을 나타냈다(p<0.05). Tyrosinase 저해효과에서는 열매 추출물이 가장 높은 저해능을 보였다. 아질산염 소거능은 모든 추출물이 산성조건에서 소거능이 높게 나타났고, 추출조건과 상관없이 잎 추출물의 소거능이 가장 높은 것으로 분석되었다. ACE 저해 활성은 열매 물 추출물에서 85.14%의 활성을 가장 높은 경향을 보였다. 꾸지뽕 나무의 부위 및 용매에 따라 각각 활성이 다르게 나타났다. 이러한 결과를 토대로 활성이 다소 뛰어난 잎의 경우, 일상에서도 쉽게 구할 수 있어 일반인들이 식용으로 이용하기 용이하므로 차와 음료 등의 건강 음료개발을 통해 소비를 활성화할 수 있다. 그 외 줄기, 열매 등도 잎과 함께 이를 이용한 환, 캡슐 등의 다양한 기능성식품으로의 개발 가능성을 확인하였다.

Spectrofluorometric Properties of N-Terminal Domain of Lumazine Protein from Photobacterium leiognathi

  • Kang, Kyoung-Suk;Kim, So-Young;Lee, Jung-Hwan;Nam, Ki-Seok;Lee, Eui Ho;Lee, Chan Yong
    • Bulletin of the Korean Chemical Society
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    • 제34권6호
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    • pp.1673-1678
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    • 2013
  • Lumazine protein is a member of the riboflavin synthase superfamily and the intense fluorescence is caused by non-covalently bound to 6,7-dimethyl 8-ribityllumazine. To figure out the binding modes and the structure of the N-terminal domain of lumazine protein, the wild type of protein extending to amino acid 118 (N-LumP 118 Wt) and mutants of N-LumP 118 V41W, S48W, T50W, D64W, and A66W from Photobacterium leiognathi were purified. The biochemical properties of the wild type and mutants of N-LumP 118 proteins were analyzed by absorbance and fluorescence spectroscope. The peak of absorbance and fluorescence of lumazine ligand were shifted to longer wavelength on binding to N-LumPs. The observed absorbance value at 410 nm of lumazine bound to N-LumP 118 proteins indicate that one mole of N-LumP 118 proteins bind to one mole of ligand of lumazine. Fluorescence analysis show that the maximum peak of fluorescence of N-LumP S48W was shifted to the longest wavelength by binding with 6,7-dimethyl 8-ribityllumazine and was shown to the greatest quench effect by acrylamide among all tryptophan mutants.

Effect of Acacia karroo Supplementation on Growth, Ultimate pH, Colour and Cooking Losses of Meat from Indigenous Xhosa Lop-eared Goats

  • Ngambu, S.;Muchenje, V.;Marume, U.
    • Asian-Australasian Journal of Animal Sciences
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    • 제26권1호
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    • pp.128-133
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    • 2013
  • The objective of the study was to determine the effect of Acacia karroo supplementation on growth, ultimate pH, colour and cooking losses of meat from indigenous Xhosa lop-eared goats. Eighteen castrated 4-month-old kids were used in the study until slaughter. The kids were subdivided in two treatment groups A. karroo supplemented (AK) and non-supplemented (NS). The supplemented goats were given 200 g per head per d of fresh A. karroo leaves. The kids were slaughtered on d 60 and sample cuttings for meat quality assessment were taken from the Longistimus dorsi muscle. The supplemented kids had higher (p<0.05) growth rates than the non-supplemented ones. The meat from the A. karroo supplemented goats had lower (p<0.05) ultimate pH and cooking loss than the meat from the non-supplemented goats. Acacia karroo supplemented goats produced higher (p<0.05) $b^*$ (yellowness) value, but supplementation had no significant effect on $L^*$ (lightness) and $a^*$ (redness) of the meat. Therefore, A. karroo supplementation improved growth performance and the quality of meat from goats.

高電壓 nozzle 형 오존발생기에 관한 연구 (A study on the high voltage nozzle type ozonizer)

  • 송현직;이광식;이동인;조환
    • 대한전기학회논문지
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    • 제44권1호
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    • pp.97-103
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    • 1995
  • This paper reports the following two topics : $\circled1$ ozone concentration (O$\sub$3con/) and discharge characteristics in flowing O$\sub$2/ with variation of Re$\sub$3/ at high voltage nozzle (HVN) of HVN 10 type ozonizer. $\circled2$ O$\sub$3con/ with variation of Re$\sub$3/ at HVN of HVN 25 type ozonizer. The important conclusions obtained from this paper are as follows. 1) In HVN 10 type ozonizer : $\circled1$ The discharge pattern can be controlled by adjustment of the Re$\sub$3/. $\circled2$ V$\sub$c/ is inversely proportional to pulse width (P$\sub$w/) and pulse frequency (P$\sub$f) $\circled3$ O$\sub$3con/ increase as decreasing of Re$\sub$3/ for constant P$\sub$w/ and P$\sub$f/. $\circled4$ O$\sub$3con/ increase as decreasing of P$\sub$w/, O$\sub$3con/ is proportional to P$\sub$f/. 2) In HVN 25 type ozonizer : O$\sub$3con/ of HVN 25 type ozonizer can increase than that of HVN 10 type ozonizer, according to parallel circuit of applied voltage and serial of supplied gas. As a result, we can obtain O$\sub$3con/ of 825[ppm] as the maximun value.

SiON buffer layer를 이용한 MFIS Capacitor의 제작 및 특성 (Fabrications and properties of MFIS capacitor using SiON buffer layer)

  • 정상현;정순원;인용일;김광호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.70-73
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    • 2001
  • MFIS(Metal-ferroelectric-insulator- semiconductor) structures using silicon oxynitride(SiON) buffer layers were fabricatied and demonstrated nonvolatile memory operations. Oxynitride(SiON) films have been formed on p-Si(100) by RTP(rapid thermal process) in O$_2$+N$_2$ ambient at 1100$^{\circ}C$. The gate leakage current density of Al/SiON/Si(100) capacitor was about the order of 10$\^$-8/ A/cm$^2$ at the range of ${\pm}$ 2.5 MV/cm. The C-V characteristics of Al/LiNbO$_3$/SiON/Si(100) capacitor showed a hysteresis loop due to the ferroelectric nature of the LiNbO$_3$ thin films. Typical dielectric constant value of LiNbO$_3$ film of MFIS device was about 24. The memory window width was about 1.2V at the electric field of ${\pm}$300 kV/cm ranges.

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Microcrystalline Si TFTs with Low Off-Current and High Reliability

  • Kim, Hyun-Jae;Diep, Bui Van;Bonnassieux, Yvan;Djeridane, Yassine;Abramov, Alexey;Pere, Roca i Cabarrocas
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1025-1028
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    • 2005
  • Microcrystalline Si (${\mu}c-Si$) TFTs were fabricated using a conventional bottom gate amorphous Si (a-Si) process. A unique ${\mu}c-Si$ deposition technique and TFT architecture was proposed to enhance the reliability of the TFTs. This three-mask TFT fabrication process is comparable with existing a-Si TFT procesess. In order to suppress nucleation at the bottom interface of Si, before deposition of the ${\mu}c-Si$ an $N_2$ plasma passivation was conducted. A typical transfer characteristic of the TFTs shows a low off-current with a value of less than 1 pA and a sub threshold slop of 0.7 V/dec. The DC stress was applied to verify the use of ${\mu}c-Si$ TFTs for AMOLED displays. After 10,000 s of application of the stress, the off-current was even lowered and sub-threshold slope variation was less than 5%. For AMOLED displays, OLED pixel simulation was performed. A pixel current of 13 ${\mu}A$ was achieved with $V_{data}$ of 10 V. After the simulation, a linear equation for the pixel current was suggested.

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800kV 차단부의 무부하 압력상승 측정 (Measurement of Pressure-Rise at No-Load in 800kV Model Interrupter)

  • 장기찬;송기동;정진교;송원표;김정배;박경엽;신영준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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    • pp.475-478
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    • 1995
  • The variations of cold gas properties such as density, pressure, temperature and velocity which are dependent each other are closely related with the dielectric recovery of an interrupter. So, the pressure-rises at no-load in the puffer cylinder and in front of fixed arcing contact of 800kV model interrupter were measured experimentally using pressure transducers of strain gage type and semiconducting type, respectively. The maximum value of pressure-rise in the puffer cylinder increased almost linearly from 7.6 bar at the minimum operated pressure to 9.7 bar at the maximum operated pressure, while the pressure-rise in front of fixed arcing contact was independent with the operated pressure. The measured values will be utilized in verifying the self-developed cold flow analysis program and as an input of commercialized CFD program package.

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RF 스퍼터링법을 이용한 $LiNbO_3/Si$구조의 전기적 및 구조적 특성 (Electrical and Structural Properties of $LiNbO_3/Si$ Structure by RF Sputtering Method)

  • 이상우;김광호;이원종
    • 한국전기전자재료학회논문지
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    • 제11권2호
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    • pp.106-110
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    • 1998
  • The $LiNbO_3$ thin films were prepared directly on Si(100) substrates by conventional RF magnetron spurttering system for nonvolatile memory applications. RTA(Rapid Thermal Annealing) treatment was performed for as-deposited films in an oxygen atmosphere at 600 $^{\circ}C$ for 60 s. The rapid thermal annealed films were changed to poly-crystalline ferroelectric nature from amorphous of as-deposition. The resistivity of the ferroelectric $LiNbO_3$ film was increased from a typical value of $1{\sim}2{\times}10^8{\Omega}{\cdot}cm$ before the annealing to about $1{\times}10^{13}{\Omega}{\cdot}cm$ at 500 kV/cm and reduced the interface state density of the $LiNbO_3/Si$ (100) interface to about $1{\times}10^{11}/cm^2{\cdot}eV$. Ferroelectric hysteresis measurements using a Sawyer-Tower circuit yielded remanent polarization ($P_r$) and coercive field ($E_c$) values of about 1.2 ${\mu}C/cm^2$ and 120 kV/cm, respectively.

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전외 액츄에이터용 PBZT 세라믹스의 $WO_3$ 첨가에 따른 특성 (Characteristics of PBZT Ceramics for Electrostrictive Actuator according to $WO_3$)

  • 김규수;윤광희;윤현상;박창엽;홍재일;류주현
    • E2M - 전기 전자와 첨단 소재
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    • 제10권9호
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    • pp.909-915
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    • 1997
  • To improve the electro-induced strain and to decease the hysteresis of that W $O_3$dopant of which amount is 0~0.8wt% was added to (P $b_{0.73}$/B $a_{0.27}$)(Z $r_{0.75}$/ $Ti_{0.25}$) $O_3$+0.1wt% $Y_{2}$/ $O_3$ceramics. At the specimen with 0.4 wt% W $O_3$the electromechanical coupling coefficient( $K_{31}$ ) showed the maximum value of 23.6% at D.C 10 kV/cm electric field. At the same W $O_3$addition amount the piezoelectric constant( $d_{31}$ ) and the electro-induced strain($\Delta$$\ell$/$\ell$)showed the highest values of 182$\times$10$^{-12}$ [C/N] 210$\times$10$^{-6}$ $\Delta$$\ell$/$\ell$at D.C. 10 kV/cm electric field. respectively0 kV/cm electric field. respectivelyvely.

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