• Title/Summary/Keyword: 20C

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Studies on the development of the stone leek minor, Acrolepiopsis sapporensis Matsumura (Lepidoptera: Acrolepiidae) (파좀나방의 발육에 관한 연구)

  • Choe, Kwang Ryul
    • Korean Journal of Agricultural Science
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    • v.24 no.1
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    • pp.16-20
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    • 1997
  • Acrolepiopsis sapporensis Matsumura was reared on welsh onions in the laboratory in Taejon for observation on its bionomics; the adults were provided with 10% sugar solution. At controlled temperatures the stone leek minor female adult laid averages of about 103 at $15^{\circ}C$, 113 at $20^{\circ}C$ and 134 at $25^{\circ}C$. Adult lived for averages of about 10 days at $15^{\circ}C$, 8~9 days at $20^{\circ}C$ and $25^{\circ}C$ and 5 days at $30^{\circ}C$. The egg hatched in about 10~11 days at $15^{\circ}C$, 5~6 days at $20^{\circ}C$ and 5 days at $25^{\circ}C$. The larval stage lasted 25~26 days at $15^{\circ}C$, 11 days at $20^{\circ}C$ and 7~8 days at $25^{\circ}C$. The pupal stage lasted 13 days at $15^{\circ}C$, 9 days at $20^{\circ}C$ and 7~8 days at $25^{\circ}C$.

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STUDIES ON THE LIPID OF AQUATIC PRODUCTS (PART 3) Fatty Acid Composition the Lipid in Dried Purple Laver Marketable Products (수산물의 지질에 관한 연구(제3보) -산지별 건해태 지질의 지방산조성에 대하여-)

  • HA Bong Seuk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.11 no.4
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    • pp.219-225
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    • 1978
  • Several samples of tile dried purple laver grown and processed at the major laver producing districts, i. e Mokpo, Wando, Hadong and Jangrim, along the southern coast of Korea were Quantitatively investigated to determine composing patterns of the fatty acids by gas-liquid chromatography. The total lipid contents in dried purple laver of Hadong were $1.8\%$ being the highest value. Upon analyzing fatty acid composition, some differences were observed in their quantitative distribution at different growing places. Dried purple laver of Wando contained mainly $C_{16:0},\;C_{18:1},\;C_{16:1}\;and\;C_{17:0}$ fatty acids, that of Mokpo contained $C_{16:0},\;C_{20:5},\;C_{18:1}\;and\;C_{16:1}$ fatty acids, and that of Hadong $C_{16:0},\;C_{20:5},\;C_{18:0}\;and\;C_{20:1}$ fatty acids, and that of Jangrim $C_{20:5},\;C_{16:0},\;C_{18:1}\;and\;C_{18:0}$ fatty acids, each in order of acid quantity. In regard to the composing pattern of carbon number of fatty acids, the dried purple laver o Mokpo, Hadong, and Jangrim contained $C_{16},\;C_{18}\;and\;C_{20}$ fatty acids with the identical distributional pattern, while that of Jangrim contained $C_{16},\;C_{18}\;and\;C_{17}$ fatty acids as major components. Dried Purple laver of Jangrim contained especially high amount of $C_{20:5}$ fatty acids.

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Change in Quality of Frozen Breaded Raw Shrimp by Storage Temperature Fluctuation (빵가루 입힌 냉동새우의 동결저장중 온도변동에 의한 품질변화)

  • Jeong, Jin-Woong;Jo, Jin-Ho;Lim, Sang-Dong;Kang, Tong-Sam
    • Korean Journal of Food Science and Technology
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    • v.23 no.5
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    • pp.532-537
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    • 1991
  • Effect of storage temperature fluctuation on quality of frozen breaded raw shrimp was studied. Storage experiments were undertaken as follows; First, after storage at $-20^{\circ}C$ for 20 days or 40 days, storage temperature of materials were raised to $-15^{\circ}C\;or\;15^{\circ}C$, and then stored at these temperatures, And second, by repeating for 5, 10 and 15 times by 3 conditions ($-20{\rightarrow}-15^{\circ}C{\rightarrow}-20^{\circ}C,\;-20{\rightarrow}-10^{\circ}C{\rightarrow}-20^{\circ}C\;-20{\rightarrow}-5^{\circ}C{\rightarrow}-20^{\circ}C$) with temperature fluctuation during storage. Quality changes were measured by determining extractability of salt-soluble protein, volatile basic nitrogen, thiobar-bituric acid, pH and microbiological changes at regular intervals. Rise in storage temperature from $-20^{\circ}C\;to\;-15^{\circ}C$ had not caused significant change on it's quality, but rise up to $-5^{\circ}C$ caused some change in quality without relationship with storage period before temperature rise. Fluctuation of storage temperature from $-20^{\circ}C\;to\;-15^{\circ}C$ of frozen breaded raw shrimp did not cause noticeable changes on it's quality. But temperature fluctuation from $-20^{\circ}C\;to\;-10^{\circ}C\;or\;-5^{\circ}C$ caused remarkable changes of it's quality, according to the increase of fluctuation times and temperatures.

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Effects of Protected Conjugated Linoleic Acid Supplementation on Milk Fatty Acid in Dairy Cows

  • Piamphon, N.;Wachirapakorn, Chalong;Wanapat, M.;Navanukraw, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.1
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    • pp.49-56
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    • 2009
  • The objective was to determine the effects of supplementation of protected conjugated linoleic acid (CLA), CLA-20 comprising 10% each of cis-9, trans-11 and trans-10, cis-12, on milk production and fatty acid profiles in plasma and milk in lactating dairy cows. Five mid-lactation, multiparous crossbred Holstein Friesian cows with average 402${\pm}$20 kg BW were used in a 5${\times}$5 Latin square design for 21-d periods. Cows were given a total mixed ration (TMR) and supplemented with CLA-20 at 0, 20, 40, 80 and 160 g/d. The results showed that dry matter intake depression occurred in cows supplemented with CLA-20 at 160 g/d. Milk production slightly increased when CLA-20 supplementation was at 20, 40 and 80 g/d. However, 3.5% fat-corrected milk (FCM) was not affected by CLA-20 supplementation. Increased levels of CLA-20 supplementation resulted in a significantly decreased percentage of milk fat. Plasma concentrations of fatty acid were not altered by the amounts of CLA-20 supplementation except for the concentration of trans-10, cis-12 CLA. For all dietary treatments, percentages of fatty acids (C4:0, C6:0, C8:0, C13:0, C14:0 C14:1 C15:0 C15:1 C16:0, C16:1, C18:1n9t, C18:2n6t, C18:2n6c, C20:0, C18:3n6, C18:3n3, C20:1 and C20:3n6) in milk fat were similar. Concentrations of C10:0, C11:0, C12:0 and C18:1n9c were decreased cubically and C18:0 was elevated linearly (p<0.01) according to the increased amounts of CLA-20 supplemented. The linear increase was observed for cis-9, trans-11 CLA (0.62, 1.17, 1.94, 1.87 and 1.82% of total fatty acid), trans-10, cis-12 CLA (0.01, 0.63, 0.67, 0.93 and 0.95% of total fatty acid) and total CLA (0.80, 2.25, 3.16, 3.97 and 3.94% of total fatty acid) in milk fat from 0 to 160 g/d of CLA-20 supplement. In conclusion, concentration of cis-9, trans-11 CLA in milk fat was concomitantly elevated at an increasing rate with the increased amounts of CLA-20. Based on the results in this study, supplementation of CLA-20 at 80 g/d optimally enhanced total CLA in milk fat.

Characteristics of Squid Viscera Oil (오징어 내장의 지방질조성)

  • KIM Eun-Mi;JO Jin-Ho;OH Se-Wook;KIM Young-Myoung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.4
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    • pp.595-600
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    • 1997
  • The oil content and composition of squid visera were determined to obtain data for utilization of this by-product. There was no significant difference in the glycolipid (GL) and phospholipid (PL) content in Illex argentinus and Todarodes pacificus, but neutral lipid (NL) was different (p<0.05). The viscera oil of I. argentinus contained $30.50\%$ total lipid which consisted of $96.24\%$ NL, $2.63\%$ GL, $2.37\%$ PL, and contained $644mg\%$ cholesterol. The viscera oil of T. pacificus contained $30.20\%$ total lipid which consisted of $94.82\%$ NL, $2.85\%$ GL, $2.34\%$ PL, and contained $1,224\;mg\%$ cholesterol. The NL, GL and PL of viscera oil in I. argentinus mainly consist of triglyceride $(44.01\%)$, esterified steryl glycosides $(58.95\%)$ and phosphatidyl cholines $(32.36\%)$, respertively. Those of viscera oil in T. pacificus mainly consist of triglyceride $(39.63\%)$, monogalactosyl diglycerides $(51.67\%)$ and phosphatidyl cholines $(31.98\%)$, respectively. The major fatty acids of the viscera oil of I. argentinus and T. pacificus were C16 : 0, $C16\;:\;0,\;C18\;:\;1\omega9,\;C20\;:\;4\omega6,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$. In Illex argentinus, the fatty acids of NL mainly were $C16\;:\;0,\;C18\;:\;1\omega9,\;C20\;:\;4\omega6,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$. PL were $C16\;:\;1\omega7,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$ and GL were $C18\;:\;1\omega9,\;C20\;:\;5\omega3,\;22\;:\;6\omega3$. The major fatty acids of NL in T. pacificus were $C16\;:\;0,\;C18\;:\;1\omega9,\;C20\;:\;4\omega6,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$, PL were $C16\;:\;1\omega7,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$, and GL were $C18\;:\;1\omega9,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$.

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Electrochemical Evaluation and Synthesis of Pt/C and PtCo/C Catalysts for the Cathode of PEMFC (PEMFC용 캐소드를 위한 Pt/C, PtCo/C 촉매제조 및 전기화학평가)

  • Kim, Jin-Hwan;Ryu, Ho-Jin
    • Journal of the Semiconductor & Display Technology
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    • v.7 no.4
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    • pp.45-49
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    • 2008
  • For the commercialization of polymer electrolyte membrane fuel cell (PEMFC), some serious problems such as the decrease of platinum use as catalysts and a larger overpotential of oxygen reduction reaction (ORR) at cathode must be solved. In this study, 20%Pt/C and 20%PtCo/C catalysts for the cathode of PEMFC were synthesized from the chemical reduction method and evaluated using an electrochemical measurement. The ORR activity of synthesized 20%Pt/C and 20%PtCo/C had higher than that of the 20%Pt/C on the market. The synthesized 20%PtCo/C with the cobalt concentration (Pt:Co atomic ratio) from 5 to 20% showed the highest ORR activity.

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Synthesis and Oxygen Reduction Reaction Evaluation of 20% Pt/C for Polymer Electrolyte Fuel Cell (고분자전해질 연료전지용 20% Pt/C 캐소드 촉매 제조 및 산소환원반응 평가)

  • Kim, Jinhwan;Kang, Suk-Min;Thube, Dilip. R.;Ryu, Hojin
    • Korean Journal of Metals and Materials
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    • v.47 no.7
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    • pp.454-459
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    • 2009
  • In order to commercialize Polymer Electrolyte Fuel Cell (PEFC), the cathode catalyst such as Platinum supported Carbon (Pt/C) need to have a high activity of Oxygen Reduction Reaction (ORR). In this study, the 20% Pt/C was synthesized using the chemical reduction method while the crystallinity of Platinum (Pt) particles were controlled under heat treatment conditions. The activity of synthesized Pt catalysts was evaluated using electrochemical measurement. Compared with the $i_{ORR}$ at 0.8 V of 20% Pt/C heat-treated at $500^{\circ}C$ and the 20% Pt/C that were not heated and commercial 20% Pt/C, the $i_{ORR}$ at 0.8 V of 20% Pt/C heattreated at $500^{\circ}C$ was 9.5 and 1.7 times higher than those of the 20% Pt/C and commercial 20% Pt/C that were not heated. It was considered that the crystallinity and particle size affect the ORR activity of the Pt/C catalysts.

Changes in Physiological and Chemical Properties of the Potatoes during Storage (감자 저장중(貯藏中)에 일어나는 생리화학적(生理化學的) 변화(變化)에 관(關)한 연구(硏究))

  • Woo, Sang Kyu
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.12 no.3
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    • pp.297-304
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    • 1983
  • The water content, respiration rate, solid, and starch contents in the potate tuber of May Queen and Namjak stored at $5^{\circ}C$ and $20^{\circ}C$ were determined during 27 week period. Changes in appearance of the surface and internal tissue also were observed. The dormancy period of May Queen stored at $5^{\circ}C$ and $20^{\circ}C$ was 12 seeks, but Namjak at $5^{\circ}C$ and $20^{\circ}C$ were 9 weeks and 21 weeks, respectively. Greening developed from 12 weeks in the tuber of May Queen at $5^{\circ}C$ and browning of Namjak stored at $5^{\circ}C$ was observed from 6 weeks. In both potatoes stored at $20^{\circ}C$, the rates of respiration were higher than those stored at $5^{\circ}C$, and the rates increased continuously after sprouting at $20^{\circ}C$ but maintained at the low level at $5^{\circ}C$. Solid and starch contents of Namjak were always higher than those of May Queen during 27 weeks, but the levels did not change significantly with time. Solid and starch contents at $20^{\circ}C$ maintained at higher level than at $5^{\circ}C$.

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Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C20: ab initio Methods

  • Lee, Wang-Ro;Lee, Chang-Hoon;Kang, Jin-Hee;Park, Sung-Soo;Hwang, Yong-Gyoo;Lee, Kee-Hag
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.445-448
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    • 2009
  • This study examined the effect of the uptake of one and two electrons on the atomic structure of three isomers of $C_{20}$ clusters, namely the ring, bowl (corannulene like), and cage (the smallest fullerene). Geometry optimizations were performed using the hybrid density functional (B3LYP) methods for neutral, singly and doubly charged $C_{20},\;{C_{20}}^-,and\;{C_{20}}^{2-}$. These results show that the symmetry of the lowest energies for ring and bowl isomers were not changed, whereas the increasing order of energy for the cage (the smallest fullerene) isomers was changed from $D_{2h}\;<\;C_{2h}\;{\leq}\;C_2\;of\;C_{20}\;through\;Ci\;<\;C_{2h}\;<\;C_2\;<\;D_{2h}\;of\;{C_{20}}^-\;to\;Ci\;<\;C_2\;<\;D_{2h}\;<\;C_{2h}\;of\;{C_{20}}^{2-}$. The reduced symmetry isomers of the cage have comparative energy and the ground state symmetry of the neutral and single and double charged $C_{20}$ decreased with increasing number of electrons taken up in the point of energetics. Interestingly, the difference in energy between the ground state and the next higher energy state of ${C_{20}}^{2-}$ was 3.5kcal/mol, which is the largest energy gap of the neutral, single anion and double anion of the cage isomers examined.