• Title/Summary/Keyword: T/W

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A temperature adjustment process of stratified fluid induced simultaneously by sidewall thermal variation and vertical through-flow (용기의 온도변화와 수직관류가 동시에 작용하는 성층유체의 과도유동)

  • Park, Jun-Sang;Hyun, Jae-Min
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.450-455
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    • 2001
  • An analytical study is made of transient adjustment process of an initially stationary, stably-stratified fluid in a square. The boundary walls are highly-conducting. The overall Rayleigh number $R_a$ is large. Considerations are given to both opposing (${\delta}w/{\delta}T>0$) and cooperating (${\delta}w/{\delta}T<0$) configurations. The flow character in opposing configuration can be classified into (a) a forced-convection dominaut mode (${\delta}w/{\delta}T>1/\sqrt{2}$), (b) a buoyancy-convection dominant mode ($0<{\delta}w/{\delta}T<1/\sqrt{2}$), and (c) a static mode (${\delta}w/{\delta}T{\cong}1/\sqrt{2}$). Global evolutionary processes are depicted. and physical rationalizations are provided.

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Effects of Taraxacum mongolicum Extract on Blood Glucose Levels and Lipid Profiles in Streptozotocin-Induced Diabetic Rats

  • Hye Kyoung Han;Eun Young Choi
    • The Korean Journal of Food And Nutrition
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    • v.36 no.1
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    • pp.50-57
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    • 2023
  • This study was designed to evaluate antihyperglycemic and antihyperlipidemic effects of ethanol extracts of Taraxacum mongolicum(T.m.) on streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley rats were randomly assigned to five groups: normal (NC), STZ-control (DC), and three experimental groups. Diabetes was induced in Sprague-Dawley rats with a single intravenous injection [45 mg/kg body weight (b.w.)] of STZ. An ethanol extract of T.m. was orally given to diabetic rats for 14 days. Three experimental groups were additionally treated with T.m. extract at doses of 1 g/kg b.w./day for T.m.-1, 2 g/kg b.w./day for T.m.-2, and 3 g/kg b.w./day for T.m.-3. Oral administration of T.m.-2 significantly increased their body weights. T.m.-1 and T.m.-2 significantly decreased aspartate aminotransferase (AST) levels than DC. T.m.-1 and T.m.-2 group significantly decreased blood glucose levels. Total cholesterol, triglycerides, and free fatty acids were significantly decreased whereas high-density lipoprotein cholesterol was significantly increased in groups treated with T.m. extract than those in the DC group. These results support the fact that administration of T.m. extract can reduce hyperglycemia and hyperlipidemia risk in diabetic rats.

Evaluation the Feed Value of Whole Crop Rice Silage and Comparison of Rumen Fermentation according to Its Ratio (신규 조사료원 사료용 벼 사일리지의 사료가치 평가 및 급여 비율에 따른 반추위 발효성상 비교)

  • Park, Seol Hwa;Baek, Youl Chang;Lee, Seul;Kim, Byeong Hyeon;Ryu, Chae Hwa
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.40 no.4
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    • pp.236-243
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    • 2020
  • This study was to evaluate the feed value of whole crop rice silage (WCRS) and to investigate a suitable ratio of the WCRS and concentrate by an analysis of rumen fermentation. A total of 6 treatments were used according to WCRS: concentrate ratio on in vitro rumen fermentation: T1 (100:0), T2 (60:40), T3 (40:60), T4 (20:80), T5 (10:90), and T6 (0:100). The ruminal pH, total gas emission, ammonia nitrogen, and volatile fatty acid (VFA) were determined as fermentation parameters. Total nutrients digestibility trial was conducted by 4 treatments according to WCRS: concentrate ratio at 40:60 (W40), 20:80 (W20), and 10:90 (W10), respectively. Feed value was analyzed according to AOAC (2019) and nutrient digestibility was calculated based on NRC (2001). The levels of crude protein (CP), crude fat, and neutral detergent fiber of the WCRS were 12.29%, 1.67%, and 59.79%, respectively. It was found to be 51.49% as a result of predicting the total digestible nutrient of WCRS using the NRC (2001) model. In vitro rumen fermentation, T4, T5, and T6 treatments showed a greater gas emission and total VFA concentration compared with other treatments (p<0.05). Acetate and acetate to propionate ratio of T4, T5, and T6 were significantly higher than other treatments (p<0.05). There was a significant difference in the level of propionate and butyrate according to the WCRS: concentrate ratio (p<0.05). The digestibility of dry matter and CP was significantly lower in W40 than in other treatments (p<0.05); however, there was no difference in W20 and W10. In conclusion, the 20:80 (WCRS: concentrate) is beneficial for stabilizing the rumen that does not inhibit rumen fermentation and nutrient digestion. This ratio might have a positive effect on the economics of farms as a valuable feed.

Noise Test and Evaluation of a 750kW Wind Turbine Generator (750kW 풍력발전기의 소음실증)

  • Kim, Seock-Hyun;Heo, Wook;Lee, Hyun-Woo
    • Journal of Industrial Technology
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    • v.27 no.B
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    • pp.59-64
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    • 2007
  • This study introduces an environmental noise evaluation procedure and results for a wind turbine (W/T) system. Test and evaluation are required by the international standard IEC 61400-11 in the aspect of environmental effect. Test and evaluation are performed on U-50 WT model which is first developed by the domestic W/T manufacturer. W/T test model is under operation in Daekwanryung wind test site. An integrated monitoring system in the test site is utilized for the evaluation. With the noise signal, meteorological data and W/T operational data are monitored in real time by the integrated monitoring system using LabVIEW. From the measured noise data, acoustic power level are estimated and compared with those of other similar size WT under the wind speeds required by international standard.

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3:1 Bandwidth Switch Module by Using GaAs PH Diode (GaAs PIN Diode를 이용한 3:1 대역폭 스위치 모듈)

  • 정명득;이경학;박동철
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.5
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    • pp.451-458
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    • 2002
  • Absorptive type SP3T(Single Pole Three Throw) and SP8T switch modules over the 6-18 GHz are designed and fabricated. The epitaxial structure of GaAs PIN diode for switch modules are designed for low loss and high power capability. The maximum input power of SP3T and SP8T switch modules are 2 W and 1 W, respectively. The switching time with driver circuit is less than 130 nsec. The maximum insertion loss of SP3T switch module and SP8T module shows 2.8 dB and 4.2 dB, respectively. The isolation between input port and output port is more than 55 dB. Two switch modules for electronic warfare system have passed the environment tests of the related test items.

Algebraic semantics for some weak Boolean logics

  • Yang, Eun-Suk
    • Korean Journal of Logic
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    • v.9 no.2
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    • pp.1-30
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    • 2006
  • This paper investigates algebraic semantics for some weak Boolean (wB) logics, which may be regarded as left-continuous t-norm based logics (or monoidal t-norm based logics (MTLs)). We investigate as infinite-valued logics each of wB-LC and wB-sKD, and each corresponding first order extension $wB-LC\forall$ and $wB-sKD\forall$. We give algebraic completeness for each of them.

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Activity of Chlorelaa vulgaris Associated by Escherichia coli W3110 on Removal of Total Organic Carbon in Continuous River Water Flow System

  • Kong, Surk-Key;Nakajima Toshiuki
    • ALGAE
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    • v.17 no.3
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    • pp.195-199
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    • 2002
  • We investigated the association of Chlorella vulgaris and E. coli W9110 in removal of total organic carbon with the lab-scaled continuous river water flow system (CRWFS). Artificial wastewater was applied at two levels of organic carbon concentration; 1,335 $mg{\cdot}l^{-1}$ in the treatment (T)-1 and 267 $mg{\cdot}l^{-1}$ in T-2. The highest densities of C. vulgaris were $8.3{\times10^6\;cells{\cdot}ml^{-1}$ in T-1 and $6.9{\times}10^6\;cells{\cdot}ml^{-1}$ in T-2. The maximum densities of E. coli W3110 were $2.0{\times}10^8$ clony forming unit (CFU)${\cdot}ml^{-1}$ in T-1 and $3.9{\times}10^8\;CFU{\cdot}ml^{-1}$ in T-2. The densities increased during the first 11 days in T-q and 4 days in T-2, and decreased rapidly till 35th day, then increased slightly afterwards. This trend was prominent in T-2. It was inplied that wider range of nutrients was required in the growth of heterotrophic bacteria in T-2 than in T-1. The algal biomass should be increased effectively for the successful removal of organic carbon.

Weighted average of fuzzy numbers under TW(the weakest t-norm)-based fuzzy arithmetic operations

  • Hong, Dug-Hun;Kim, Kyung-Tae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.7 no.1
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    • pp.85-89
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    • 2007
  • Many authors considered the computational aspect of sup-min convolution when applied to weighted average operations. They used a computational algorithm based on a-cut representation of fuzzy sets, nonlinear programming implementation of the extension principle, and interval analysis. It is well known that $T_W$(the weakest t-norm)-based addition and multiplication preserve the shape of L-R type fuzzy numbers. In this paper, we consider the computational aspect of the extension principle by the use of $T_W$ when the principle is applied to fuzzy weighted average operations. We give the exact solution for the case where variables and coefficients are L-L fuzzy numbers without programming or the aid of computer resources.

Combination effects of nitrite from fermented spinach and sodium nitrite on quality characteristics of cured pork loin

  • Kim, Tae-Kyung;Lee, Mi-Ai;Sung, Jung-Min;Jeon, Ki-Hong;Kim, Young-Boong;Choi, Yun-Sang
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.10
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    • pp.1603-1610
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    • 2019
  • Objective: The purpose of this study was to investigate the effect of fermented spinach derived nitrite and sodium nitrite on cured pork loin. Methods: The following treatments were prepared using brine (8% [w/v] salt): Control (-), no nitrite added; Control (+), 0.08% (w/v) sodium nitrite brine; T1, 0.04% (w/v) nitrite fermented spinach juice in 0.04% (w/v) sodium nitrite brine; T2, spinach juice in 0.04% (w/v) sodium nitrite brine; T3, 0.04% (w/v) nitrite fermented spinach juice used as sodium nitrite free brine; and T4, spinach juice used as sodium nitrite free brine. T2 and T4 were incubated to allow to reduce nitrate to nitrite. Results: Spinach juice did not affect cooking loss and pH but negatively influenced flavor and overall acceptability (p<0.05). T1 samples containing synthetic and natural nitrites showed the highest redness values. Spinach juice negatively affected volatile basic nitrogen; however, thiobarbituric acid reactive substance values of T1 and T3 were similar to those of controls (+) (p>0.05). Residual nitrite content decreased with decreasing synthetic nitrite levels. T1 and control samples showed no significant differences in overall acceptability (p>0.05). Conclusion: Thus, combined synthetic and natural nitrites improved the quality of cured pork loin.

Studies on the Artificial Seedling Production of Geoduck Clam, Panope japonica II. Development of Egg and larvae (코끼리조개의 인공종묘생산에 관한 연구 II. 난발생과 유생의 발달)

  • Lee, Chae-Sung;Rho, Sum
    • Journal of Aquaculture
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    • v.10 no.1
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    • pp.25-32
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    • 1997
  • Develoment precess and characteristics of eggs of the geoduck clam, Panope japonica are reporting in this study. Eggs and sperm were excised from gonad, artificially fertilized in an aquarium, reared under various temperature regimes, and record and record the larval period and the time need to reach a certain larval stage from ferilization. Unfertilized eggs of P. japonica appeared to be oval with a mean diameter of $70\mu$m and they became spherical after fertilization. The eggs of P. japonica can be classified as demersal. At a constant water temperature of $ 11^{citc}C$, it took 4 hours form fertilization to become four-cell stage, two days to become trochophore larvae, three days to become D-shape larvae, twenty-three days to become umbo stage, and thirty-six days to become fully grown veliger ready form settlement. A negative correlation was observed between the water temperature and the larval period of P. japonica. From fertilization to D-shape larvae, it took five days at 8$^{\circ}C$, while it was only two days to become D-shape larvae at $ 17^{citc}C$. Time required to D-shape larvae from fertilization was proportional to temperature, and the relationships were expressed as follows : To 8-cell stage, 1/t=0.0209 w-0.1167 (r=0.9967) To blastula stage, 1/t=0, 0055 w-0.0192 (r=0.9825) To trochophore stage, 1/t=0.0034 w-0.0155 (r=0.9907) To D-shape larvae stage, 1/t=0.0014 w-0.0023 (r=0.9843) (t, time in hours ; w, water temperature) Bioligical minimum temperature for egg development was calculated as 3.82$^{\circ}C$ in average.

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