• Title/Summary/Keyword: $C_d$

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Studies on the Pasteurization Conditions of Takju (탁주의 저온 살균조건에 관한 연구)

  • Lee, Cherl-Ho;Tae, Won-Taek;Kim, Gie-Myung;Lee, Hyun-Duck
    • Korean Journal of Food Science and Technology
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    • v.23 no.1
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    • pp.44-51
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    • 1991
  • The thermal resistance of the important microorganisms in takju. Korean traditional turbid alcoholic beverage, was measured and optimun heating time and temperature to achieve the commercial pasteurization of these microorganisms were examined. Most of the vegetative bacterial cells in takju were destroyed by heating at over $60^{\circ}C$, except for the spore forming organisms, which did not actively grow in takju after pasteurization. The important microorganisms for the quality deterioration of pasteurized takju were then appeared to be yeast and molds, and their thermal resistances were measured. The thermal resistances of these microorganisms changed greatly depending upon the heating method. The D values of yeast in takju were 3.5 min at $65^{\circ}C$ and 0.46 min at $80^{\circ}C$ in cap-tube, and 7.1 sec at $65^{\circ}C$ and 2.3 sec at $80^{\circ}C$ in a continuous coil heat exchanger. Those of molds were 2.7 min at 65℃ and 0.25 min at $80^{\circ}C$ in cap-tube, and 3 sec at $65^{\circ}C$ and <1 sec at $80^{\circ}C$ in the coil heat exchanger. The acidity and pH did not change at $30^{\circ}C$ for two weeks after pasteurization by heating in the coil heat exchanger at $65^{\circ}C$ for 17 sec, but the viscosity increased slightly by the heat treatment. Significant differences in sensory quality, especially the formation of burnt smell and bitterness by heating takju for 12D of yeast at $70,\;80\;and\;85^{\circ}C$, respectively, were observed and this resulted in the significant reduction in overall likeness of pasteurized takju. However, when the heating temperature was fixed to $80^{\circ}C$, the overall likeness of pasteurized takju did not affected significantly by the heating time ranging from 8D to 12D of yeast. It was concluded that the optimum pasteurization condition of takju in a continuous heat exchanger was heating at $80^{circ}C$ for 23sec(10D of yeast).

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Changes in Aerodynamic Function and Closed Quotient with the Variable Pitch and Loudness in Male Classic Singers (남성 성악가의 음도고정시 강도 변화와 강도고정시 음도 변화의 공기역학 및 성대접촉율의 변화)

  • Nam, Do-Hyun;Paik, Jae-Yeon;Kim, Jae-Ok;Park, Sun-Young;Choi, Hong-Shik
    • Speech Sciences
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    • v.14 no.2
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    • pp.23-33
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    • 2007
  • This study examined the aerodynamic functions (mean airflow rate MFR, subglottal pressure Psub) and closed quotients (CQs) in the fixed pitch (C3, E3, G3, C4) with the variable loudness (70 and 80 dB) as well as in the fixed loudness at 70 dB and 80 dB with the variable pitch (C3, E3, G3, C4) in five classic male singers (Baritone). Results showed that MFR significantly increased at C3, E3, and G3 and Psub significantly increased at C4 when the loudness increased from 70 to 80 dB. At 70 dB, MFR and Psub significantly increased and CQ significantly decreased when the pitch increased from C3 to C4. At 80 dB, MFR significantly decreased when the pitch increased from C3 to G3. However, Psub showed the significant decrease with the pitch increased at 80 dB. In conclusion, as the loudness increases, the aerodynamic loss is getting higher and vocal efficiency becomes lower at low pitch than at higher pitch. At a low loudness level, the main mechanism to control loudness is the amount of medial compression of the vocal folds rather than the aerodynamic function. In addition, the aerodynamic function and medial compression of the vocal folds have a significant role in increasing the loudness level.

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A BOUND FOR THE MILNOR SUM OF PROJECTIVE PLANE CURVES IN TERMS OF GIT

  • Shin, Jaesun
    • Journal of the Korean Mathematical Society
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    • v.53 no.2
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    • pp.461-473
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    • 2016
  • Let C be a projective plane curve of degree d whose singularities are all isolated. Suppose C is not concurrent lines. P loski proved that the Milnor number of an isolated singlar point of C is less than or equal to $(d-1)^2-{\lfloor}\frac{d}{2}{\rfloor}$. In this paper, we prove that the Milnor sum of C is also less than or equal to $(d-1)^2-{\lfloor}\frac{d}{2}{\rfloor}$ and the equality holds if and only if C is a P loski curve. Furthermore, we find a bound for the Milnor sum of projective plane curves in terms of GIT.

Transient Characteristics of Separately Excited d-c Motor Driven by Thyristor d-c Chopper (Thyristor 직류 Chopper방식으로 구동되는 직류타여자식 전동기의 과도특성해석법)

  • Hee Young Chun
    • 전기의세계
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    • v.21 no.2
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    • pp.9-19
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    • 1972
  • The transient characteristics of separately excited d-c motor driven by thyristor d-c chopper is studied in this paper. The armature controlled system is applied. As a result of theoretrical analysis the following conculsions were drawn: (1) For the transient analysis, it is recognized that the state transition analysis is a more general method and powerful tool than the state equation method or signal flow graph method, although it includes iterative matrix calculations. And the system is dealt with a finite width sampled-data system in the state transition analysis. (2) The transient characteristics of the motor angular velocity and its torque to the sampling duration variation are compared with those due to the amplitude variation of d-c chopper voltage as follows. The attenuation rate of the transient characteristics is equal in both cases, but the initial value of the transient characteristics in former case is greater than in latter case. (3) The roots of characteristics equation of the system lie inside the unit circle of the Z-plane. Therefor the system is stable. Further it is found that as the sampling duration is decreased the relative stability is lessened.

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Actinomycins에 의한 Adenosine Deaminase의 억제

  • 김경자;조성진
    • Microbiology and Biotechnology Letters
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    • v.24 no.3
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    • pp.380-383
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    • 1996
  • Adenosine deaminase inhibitor was extracted from culture broth of Streptomyces sp. strain V-8 with ethylacetate. The ethylacetate extract showed the characteristic UV absorption spectrum of actinomycins at 440-450 nm. The ethylacetate extract was compared with respect to inhibitory behavior against adenosine deaminase from calf intestinal mucosa with actinomycin D, -C complex and actinomycin V. The Ki values for actnomycin D, -C complex, and actinomycin V against adenosine deaminase were determined to be 9.9 $\times$ 10$^{-6}$ M, 9.6 $\times$ 10$^{-6}$ M and 9.3 $\times$ 10$^{-6}$ M, respectively. The Ki value for the ethylacetate extract of culture broth against adenosine deaminase was determined to be 5.7 $\times$ 10$^{-6}$ M. The kinetic parameters of actinomycin D, -C complex, -V and ethylacetate extract of culture broth for adenosine deaminase were as follows:I$_{50}$ = 1.5 $\times$ 10$^{-5}$ M (actinomycin D), 2.7 $\times$ 10$^{-5}$ M (actinomycin C complex), 3.5 $\times$ 10$^{-5}$ M (actinomycin V), 8.9 $\times$ 10$^{-6}$ M (ethylacetate extract of culture broth). The adenosine deaminase was inhibited noncompetitively by ethylacetate extract of culture broth as well as by actinomycin D, -C complex and actinomycin V.

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Revision of $^{13}C$ NMR Assignments of ${\beta}-Sitosterol$ and ${\beta}-Sitosteryl-3-O-{\beta}-D-glucopyranoside$ Isolated from Plantago asiatica Seed (질경이씨로 부터 분리한 ${\beta}-Sitosteryl-3-O-{\beta}-D-glucopyranoside$${\beta}-Sitosterol$$^{13}C$ NMR)

  • Chang, Il-Moo;YunChoi, Hye-Sook;Yamasaki, Kazuo
    • Korean Journal of Pharmacognosy
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    • v.12 no.1
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    • pp.12-14
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    • 1981
  • ${\beta}-Sitosteryl-3-O-{\beta}-D-glucopyranoside$ was isolated from the seeds of Plantago asiatica (Plantaginaceae). The assignments of $^{13}C$ NMR spectra of ${\beta}-sitosterol$ and ${\beta}-sitosteryl-3-O-{\beta}-D-glucopyranoside$ were made by comparing with $^{13}C$ NMR spectra of cholesterol and $cholesteryl-3-O-{\beta}-D-glucopyranoside$. Our data indicate that the revision of previous $^{13}C$ NMR spectral assignment is needed.

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Multimedia Management & Protection Service focus on user in Ubiquitous Home (유비쿼터스 홈에서의 사용자 중심 멀티미디어 관리/보호 서비스)

  • Park Jong-Hyuk;Song Jung-Suk;Lee Seung-Heon;Park Heung-Soo;Kim Sung-Soo
    • 한국정보통신설비학회:학술대회논문집
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    • 2004.08a
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    • pp.109-112
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    • 2004
  • 오늘날 급속한 컴퓨팅 환경의 변화에 따라 방송, 통신, 기계 등 디지털 컨버전스 패러다임으로 데스크탑 컴퓨터에 제한적이던 정보 서비스가 언제, 어느곳에서든 가능한 유비쿼터스 시대가 도래하고 있다. 가정에서도 또한, 유비쿼터스 홈 환경이 조성 되면서 댁내 보안, 건강 모니터링 및 진료, 오락, 교육, 전자상거래 등 다양한 서비스가 이루어질 것이다. 이러한 환경에 적절한 멀티미디어 컨텐츠의 안전하고 체계적인 관리 및 보호가 필요할 것이다. 본 논문에서는 이러한 유비쿼터스 환경에서의 멀티미디어서비스를 사용자의 상황인지 정보를 통해 지능화된 미디어 서비스 및 멀티미디어 컨텐츠의 체계적이고 안전한 관리 및 보호를 위한 시스템을 제안한다.

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Simulation on the Microstructure Development of Porous Materials with Respect to the Surface Energy Anisotropy (표면에너지의 이방성에 따른 다공체의 조직변화 시뮬레이션)

  • Shin, Soon-Gi
    • Korean Journal of Materials Research
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    • v.17 no.9
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    • pp.500-506
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    • 2007
  • The effects of anisotropic surface energy on the microstructure development of porous materials have been studied through Monte Carlo simulation using a three dimensional lattice. The changes in porosity ($f_v$), mean grain diameter ($D_s$), fraction of connected pores ($f_{v,c}$) and contiguity of the solid phase (C) were examined in cases with three different ${\gamma}_{SV}$ relations and initial grain diameters ($D_{s,o}$). It has been found that larger ${\gamma}_{SV}$ enhances sintering of particles and increases C and does not change $D_s$. And Introducing anisotropic ${\gamma}_{SV}$ brought an increase in $f_v$ and $f_{v,c}$ and an decrease in $D_s$ and C, and this tendency become more marked for fine $D_{s,o}$.

PD Characteristics in C-GIS Using AE Sensor (AE Sensor를 적용한 C-GIS내의 PD 특성)

  • Lee, Yong-Hee;Shin, Yang-Sop;Jang, Su-Hyeong;Seo, Jung-Min;Lee, Yong-Hee;Lim, Ki-Joe
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1652-1654
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    • 2002
  • The defects making partial discharge(PD) in a C-GIS(Cubicle Insulated Switchgear) initiate acoustic wave which can be detected using acoustic emission sensor placed outside or inside the C-GIS enclosure. In this paper, partial discharge property for 2 locations for AE sensor and 3 locations for defects in C-GIS are presented and PD waveforms were analyzed by PRPDA(Partial Resolved Partial Discharge Analysis). As a result, using post amplifier having gain of 10,000 and band pass filter having $20kHz{\sim}300kHz$, resolution of waveforms AE sensor signal by detected was good. Noise level was about 80 mV.

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Synthesis and Properties of Anionic Tetrakis(pentafluorophenyl)indium(Ⅲ) Complexes (Tetrakis(pentafluorophenyl)indium(Ⅲ) 음이온 착물의 합성과 특성)

  • Choi, Zel Ho
    • Journal of the Korean Chemical Society
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    • v.43 no.1
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    • pp.52-57
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    • 1999
  • The anionic complexes, [ln($C_6F_5)_4$]-, which are thermal and moisture sensitive, have been prepared by the reaction of In($C_6F_5)_3{\cdot}D(D=CH_3CN$, O($C_2H_5)_2$) with the system ($CH_3)_3SiC_6F_5$/CsF, $C_6F_5$MgBr or Cd($C_6F_5)_2$. The stable anionic indium(III) complexes are obtained through cation exchange with PNPCI ([PNP]= bis(triphenylphosphino)ammonium). The pure substance is obtained by column chromatography. These new anionic complexes are unambiguously identifed by NMR-spectroscopy, IR spectroscopy, molecular weight, DTA/TG and elemental analysis.

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