• Title/Summary/Keyword: S20C

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Effect of Temperature and Salinity on Production of Resting Egg in Korean Rotifer, Brachionus plicatilis (L and S-type)

  • Park, Heum-Gi;Hur, Sun-Bum
    • Journal of Aquaculture
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    • v.9 no.4
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    • pp.321-327
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    • 1996
  • Production of resting egg from the Korean rotifer, Brachiunus plicatilis (L and S-type) was investigated at different temperatures (L-type : 20, 24, $28^{\circ}C$, S-type : 28 32, $36^{\circ}C$) and salinities (10, 20,30 ppt). The rotifer was cultured in 25 ml test tube and fed on Nannochloris oculata. With regard to mixis rate, L-type rotifer showed higher rate at lower temperature, and the highest rate was observed at 20 ppt of salinity at each temperature of the experiment. However, for S-type rotifer, the optimum temperature and salinity were $28\~32^{\circ}C$ and 20 ppt, respectively. The highest number of resting egg was 173 eggs/ml in 16 days at $24^{\circ}C$, 10 ppt for L-type rotifer and 410 eggs/ml in 14 days at $28^{\circ}C$, 10 ppt for S-type rotifer. The maximum number of resting egg produced per 10,000 rotifers was 8,122 eggs at $20^{\circ}C$, 20 ppt for L-type rotifer and 8,700 eggs at $28^{\circ}C$, 20 ppt for S-type rotifer. The maximum number of resting egg produced $10^8$ cells of N. oculata was 50.7 eggs for L-type rotifer ($24^{\circ}C$, 20 ppt) and 79.6 eggs for S-type rotifer ($32^{\circ}C$, 10 ppt). The number of resting egg produced per day was $1\~11$ eggs/ml for L-type rotifers and $21\~35$ eggs/ml for S-type rotifer in 9 combination experiments. In this study, S-type rotifer is better than L-type rotifer in resting egg production, and the optimum temperature and salinity for resting egg production were $20^{\circ}C$, 20 ppt for L-type rotifer and $28^{\circ}C$, 20 ppt for S-type rotifer. This result shows the difference of Korean rotifer in the optimum condition for resting egg production from other rotifers reported earlier.

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The Characteristics on Western Men's Underclothes in the Second Half of the 20C (20세기 후기에 나타난 서양 남성 속옷의 특성)

  • 김주애
    • Journal of the Korean Society of Costume
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    • v.51 no.7
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    • pp.111-121
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    • 2001
  • The purpose of this study was to investigate the historical changes, and analyze functions and characteristics of western men's underclothes in the second half of the 20C. This study will examine how the social backgrounds influenced on the changes of the functions of men's underclothes and how the changes of outer garments were reflected on underclothes in the second half of the 20C. In the early, the second half of the 20C, underwears of functions was continued to cleanliness and comforts. In the later of the 20C, underwears came to be seen as expressing male sexual power when it became body-conscious. By the changes of outer garments. underclothes changed the same size of proportion. In the late 1960's, the turtleneck type of shirts were copied by outer garments, and we understand that underwear can influence on outer garments. The ruffles of the 18th century reappeared in the 1960's. This reactionism of the late 20C tells us about the relation between social environments and underwear. So the social backgrounds influenced on the formativeness of men's underclothes. We understand that underwear can influence on outer garments and outer garments can influence on underwear, too. The important characteristics of the second half of the 20C were the remarkable resemblance of some styles to those of the Past and the occasional blurring of the distinction between underwear and outerwear.

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Effects of Washing and Storage Temperature on Quality and Safety of Washed Shell Eggs (세척 수 및 보관온도가 세척 식용란 품질과 안전에 미치는 영향)

  • Choi, Bum-Geun;Min, Ji-Hyeon;Yoon, Ki-Sun
    • Journal of the East Asian Society of Dietary Life
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    • v.27 no.1
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    • pp.78-87
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    • 2017
  • The objective of this study was to investigate the effects of various washing waters on the quality and safety characteristics of eggs during storage. Eggs were washed with tap water, 100 ppm of sodium hypochlorite, or 30 ppm of slightly acidic electrolyzed water and stored at $10^{\circ}C$ and $20^{\circ}C$. Effects of various washing waters on reduction of Salmonella Enteritidis and aerobic plate counts and survival of S. Enteritidis on egg shells were also analyzed at $10^{\circ}C$ and $20^{\circ}C$ for 25 days. As an index of quality, haugh unit, weight reduction, and pHs of egg white and egg yolk were measured. Reduction percentages of haugh unit and weight were higher at $20^{\circ}C$ than at $10^{\circ}C$. Egg qualities were less affected by tap water, slightly acidic electrolyzed water, and sodium hypochlorite, regardless of storage temperature. The greatest reductions in aerobic plate counts and S. Enteritidis were observed with slightly acidic electrolyzed water. The level of S. Enteritidis on egg shells gradually decreased during 20 days of storage at both $10^{\circ}C$ and $20^{\circ}C$, whereas S. Enteritidis survived longer at $20^{\circ}C$ than at $10^{\circ}C$. S. Enteritidis was not detected in eggs at $10^{\circ}C$, 2.13 log CFU/g of S. Enteritidis was detected in eggs washed with sodium hypochlorite after 20 days of storage at $20^{\circ}C$, indicating that S. Enteritidis penetrated into the egg shell during storage at $20^{\circ}C$. In conclusion, slightly acidic electrolyzed water increased microbial reduction and least affected quality of washed eggs. Thus, slightly acidic electrolyzed water can be recommended for washing of graded eggs, at retail markets.

Complete Assignment of $^{1}H$ and $^{13}C$-NMR Signals for (20S) and (20R)-Protopanaxadiol by 2D-NMR Techniques (2D-NMR 기법을 이용한 (20S)와 (20R)-Protopanaxadiol의 $^{1}H$- 및 $^{13}C$-NMR 완전 동정)

  • 백남인;김동선
    • Journal of Ginseng Research
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    • v.19 no.1
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    • pp.45-50
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    • 1995
  • (20S)- and (20R)-protopanaxadiol were prepared from crude ginseng saponin by chemical treatment. The $^{1}H$- and $^{13}C$-NMR signals of these compounds were fully assigned by various NMR techniques such as DEPT, 1H-1H COSY, HMQC, HMBC and NOESY.

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Development of Mathematical Model for the Hydrolysis Fish Oil (물고기 기름의 가수분해에 대한 수학적 모형개발)

  • Kim Won-Ho;Lee Yong-Hoon;Park Ji-Suk;Hur Byung-Ki
    • KSBB Journal
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    • v.20 no.2 s.91
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    • pp.106-111
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    • 2005
  • The functional relationship between the number of mole of an i-fatty acid (Si) included in fish oil and the hydrolysis time(t) was expressed as a mathematical model, $S_i=-{\alpha_i}1n(t)+\beta_i$. The average errors of calculated values on the basis of the measured values were distributed in the range of less than $5\%$ for all the 15 fatty aids composing of fish oil. The equation of hydrolysis rate of each fatty acid was deduced as $v_i={\gamma_i}exp(\frac{S_i}{\alpha_i})$ from the above-mentioned $S_i=-{\alpha_i}ln(t)+{\beta_i}$. Therefore the hydrolysis yields of fatty acids were analyzed using the equation of $S_i\;Vs.\;t.$. The 15 fatty acids were categorized into 4groups from the view point of hydrolysis yield. The hydrolysis yields of the first group, including C14:0, C16:0, C16:1, C18:0, C18:1 (n-7) and 1l8:1 (n-9), were higher than $70\%$ at 48 hr of hydrolysis. Those of the second group, C20:1, C22:1, C18:3, C20:4 and C20:5, were distributed from $40\%,\;to\;60\%$, and third group were around $30\%$. The final group containing only C22:6 was very hard to be hydrolyzed and the yield was less than $20\%$ at the same time.

A Study on the Syrup using for Yackwa (약과(藥果)에 쓰이는 Syrup에 관(關)한 연구(硏究))

  • Chun, Hui-Jung;Lee, Hyo-Ti
    • Korean Journal of Food Science and Technology
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    • v.7 no.3
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    • pp.135-140
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    • 1975
  • Among many honeys, the buckwheat honey was the best one using for Yackwa(a Korean cookie). We made a substitute, similary syrups of buckwheat honey, and then we got the following conclusions through the case of the similar syrups. 1. The best syrups are A, B and C syrup. A syrup's composition rate was sugar (40%), corn-syrup (20%) and water (40%) before boiling for 10 minutes. B syrup's composition rate was water (40%), glucose (20%), corn-syrup (20%) and sugar (20%) before boiling for 15 minutes. C syrup's composition rate like B syrup's but boiled for 10 minutes. 2. The best syrups used for dough are A and B syrup. C syrup was good for soaking. When A syrup used for dough, we have to immediate soaking in A syrup after frying or soaking in C syrup an hour later after frying. When B syrup used for dough, we must soaking in C syrup an hour later after frying. 3. The rate of fat in the composition of buckwheat honey's, A syrup's and B syrup's Yackwa was 27.22%, 23.05%, 23.05% and 30.35%.

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Effect of water potential on mycelial growth, reproduction, and spore germination by Cylindrocladium crotalariae (Cylindrocladium crotalariae의 균사자람, 포자형성과 포자발아에 대한 Water potential의 효과)

  • Sung Jae Mo;Heo No Youl;Kim Se Keun
    • Korean journal of applied entomology
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    • v.20 no.1 s.46
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    • pp.37-41
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    • 1981
  • Mycelial growth and production of macroconidia by Cylindrocladium crotalariae on either PDA or water agar containing soybean leaf pieces adjusted to different water potentials with KCI. were consistently maximal at -14bars. Mycelial growth by this fungus was nii at about -100 bars and below at 30C, -80 bars and below at 25C and -64 bars and below at 20C. Sporulation was prevented at -64 bars and below at $20^{\circ}C\;and\;25^{\circ}C$. Perithecial andmicrosclerotial formation was maximal at abot -1.4 to - 3.0 bars (the basal medium without sait). Percentage of spore germination for this fungus was uniformly maximal at all water potentials between -1.4 bars (the highest tested) and - 20 bars, was progressively less as the water potential lowered below -20 bars, and was prevented at - 60 bars.

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Optimum Culture Condition on Four Species of Microalgae used as Live Food for Seedling Production of Bivalve (이매패류 먹이생물로 이용되는 미세조류 4종의 적정 배양환경조건)

  • Min, Byeong-Hee;Hur, Sung Bum
    • The Korean Journal of Malacology
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    • v.31 no.1
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    • pp.35-41
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    • 2015
  • In order to investigate the live food value of microalgae for efficacious rearing of larvae and spats of bivalve, we studied growth rates of four microalgal species (Isochrysis galbana, Pavlova lutheri, Chaetoceros simplex, Tetraselmis tetrathele) cultured in different environmental conditions. These include changes in temperatures (20, 25, 30 and $35^{\circ}C$), salinities (20, 25, 30 and 33 psu) and light intensities (60, 100 and $140{\mu}mol\;m^{-2}s^{-1}$). The growth rate of I. galbana was faster at $25^{\circ}C$ than that of $20^{\circ}C$. At $25^{\circ}C$ the highest growth rate of I. galbana was observed at 33 psu (0.413) and the lowest at 20 psu (0.368) in 10 days of culture (P < 0.05). The growth rate of I. galbana was lower at 25 psu (0.383) than that of 30 psu and higher than that of 20 psu (P < 0.05). Similar temperature and salinity-dependent changes were also found in P. lutheri and T. tetrathele. C. simplex showed faster growth rate at $30^{\circ}C$ than that of $25^{\circ}C$. The highest growth rate of C. simplex was observed at 33 psu (0.428) and the lowest at 20 psu (0.389) in 10 days of culture (P < 0.05). Upon exposure to the light with different intensities, all four microalgal species showed a significantly faster growth rate at $140{\mu}mol\;m^{-2}s^{-1}$ than at $100{\mu}mol\;m^{-2}s^{-1}$ (P < 0.05).

Direct Determination Method of Antimony in High Purity Copper Metal by Graphite Furnace Atomic Absorption Spectrometry (흑연로 원자 흡수흡광법에 의한 고순도 구리 합금중의 안티몬의 직접 분석 방법)

  • Yoo, K.S;Kyung, J.D;Kwon, J.G;Lee, J.J
    • Journal of the Korean Chemical Society
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    • v.39 no.4
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    • pp.252-256
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    • 1995
  • A study was carried out for the development of direct determination of antimony in high purity copper metal without preseparation. The large excess of copper seemed to be performed as the matrix modifier to enhance the absorbance of antimony in copper metal. Sensitivity enhancement of Sb was obtained at the condition of the ashing temperature of $600^{\circ}C(20s){\sim}700^{\circ}C(10s)$ rather than $1000^{\circ}C(20s){\sim}1100^{\circ}C(10s)$, and the atomization temperature of $2200^{\circ}C.$ The operating pressure of argon gas was readjusted to the optimum condition at 2.0 kg/$cm^2.$ The linearity of the Sb calibration graph could be obtained in the range of 20 ppb up to 200 ppb Sb in existence of 5,000 ppm Cu with the coefficient of variation of about 5%.

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The synthesis and crystal structure of $[({\eta}^5-Cp)Co]_2$(1,2-S,S-o-Carborane) $(C_{12}H_{20}B_{10}S_2Co_2)$ ($[({\eta}^5-Cp)Co]_2$ (1,2-S,S-o-Carborane) $(C_{12}H_{20}B_{10}S_2Co_2)$의 합성 및 결정구조)

  • Cho, Sung-Il
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.18 no.2
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    • pp.62-67
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    • 2008
  • An Organometallic compound, $C_{12}H_{20}B_{10}S_2Co_2$, was synthesized from o-carborane, $Cp^*Co(S_2B_2B_{10}H_{10})$ and $BH_3{\cdot}THF$. The molecular structure of this complex has been determined by X-ray diffraction. Crystallographic data: monoclinic, space group Cc, a=15.981(4) ${\AA}$, b=15.478(17) ${\AA}$, c=12.0562(17) ${\AA}$, ${\beta}=115.063(16)^{\circ}$, Z=4, V=9683(4) ${\AA}^3$. The structure was solved by direct methods and refined by full-matrix leat-squares methods to give a model with a reliability factor R = 0.0630 for 9948 reflections.