• Title/Summary/Keyword: C58

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Effect of Plant Density and Planting Date on Growth and Grain Yield of Maize Hybrids (파종기와 재식밀도가 단교잡종옥수수의 생육 및 종실수량에 미치는 영향)

  • Cho, J.Y.;Kwon, H.J.;Kang, Y.K.;Jong, S.K.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.2
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    • pp.227-232
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    • 1983

  • Two single cross maize hybrids planted on May 4 and 25 and June 15, 1982 were grown at 40,000:55,000 70,000 and 85,000 plants per hectare to evaluate plant density effect on growth and grain yield at different planting dates. Two hybrids with different leaf angle (Suweon 19 with horizontal leaves and Suweon 58 with erect leaves) and the same maturity were used. The number of days from planting to silking varied from 74 to 58 days as planting was delayed from May 4 to June 15. However, growing degree days from planting to silking was about $810^{\circ}C$ regardless planting dates. Grain yields of two hybrids were significantly decreased as planting was delayed. The number of ears per 100 plants and the number of kernels per ear of two hybrids were linearly decreased with increasing plant density. The optimum plant density for Suweon 19 estimated by Duncan's method was about 55,000 plants hectare for May 4 and 25 plantings and decreased to 32,000 plants/hectare for June 15 planting. The optimum density for Suweon 58 was estimated to be about 71,000 plants/hectare for May 4 planting and 54,000 plants/hectare for May 25 planting, respectively.

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Changes of Triglyceride Composition in Adlay Powder during Storage (율무가루 저장 중 Triglyceride 조성의 변화)

  • Han, Ji-Sook;Rhee, Sook-Hee;Cheigh, Hong-Sik
    • Korean Journal of Food Science and Technology
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    • v.23 no.1
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    • pp.102-108
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    • 1991

  • Raw adlay powder(RAP)was prepared and the changes of triglyceride composition in RAP lipid during storage at $35^{\circ}C$ for six months were studied. The RAP lipid consisted of 28 kinds of triglycerides and the major triglyceride in RAP lipid were those of OOL(24.14%), OLL(24.06%), OOO(12.58%), POL(9.01%), POO(8.87%), LLL(7.91%)and PLL(5.80%). During the storage at $35^{\circ}C$ for six months, the relative amounts of the triglyceride containing linoleic acid(OLL : 15.25%, LLL : 2.93%)considerably decreased, but those containing oleic acid(OOO : 23.77%. POO : 12.62%) increased. The triglycerides of LLA(0.44%)and PPLn(0.12%)disappeared during the storage.

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Preparation of Methylenediphenyldiurethanes by the Acid Rearrangement of [(Ethoxycarbonyl)phenylaminomethyl] phenylcarbamic Acid Ethyl Esters ([(에톡시카르보닐)페닐아미노메틸]페닐카르바민산 에틸에스테르의 산 재배열에 의한 메틸렌 디페닐디우레탄의 제조)

  • Park, Nae-Joung
    • Applied Chemistry for Engineering
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    • v.7 no.1
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    • pp.51-58
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    • 1996

  • The rearrangement of [(ethoxycarbonyl)phenylaminomethyl]phenylcarbamic acid ethyl esters(N-benzyl compounds) to methylenediphenyldiurethanes(MDU) in sulfuric acid, sulfuric acid-absolute ethanol solvent system, and sulfuric acid-nitrobenzene solvent system, and boron trifluoride at $90^{\circ}C$ was studied. The production of MDU was the highest in sulfuric acid-nitrobenzene system giving 64% MDU yield, of which 58% was 4,4'-MDU. The simultaneous condensation of EPC and formaldehyde and rearrangement to MDU were studied in the presence of different amounts of sulfuric acid, trifluoroacetic acid, and boron trifluoride at $70^{\circ}C$. Though 17mmol of sulfuric acid with 30mmol of EPC produced the highest MDU, the MDU yield was much lower than that from separate condensation and rearrangement reaction.

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Study on the Latent Heat Characteristics of the Organic Compound, $C_{28}H_{58}$ and the Inorganic Compound, $CH_3COONa{\cdot}3H_2O$ (유기잠열재, $C_{28}H_{58}$과 무기잠열재, $CH_3COONa{\cdot}3H_2O$의 잠열특성연구)

  • Song, Hyun-Kap;Ryou, Young-Sun
    • Solar Energy
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    • v.11 no.3
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    • pp.53-61
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    • 1991

  • In this research, Octacosane($C_{28}H_{58}$) and Sodium Acetate Trihydrate($CH_3COONa{\cdot}3H_2O$) were selected as latent heat storage materials to store off-peak electricity or waste heat of an industrial plant. Experimental analyses were performed in terms of the variation of phase change temperature and latent heat, phase change stability for the long term utilization. The results were as follows. 1. The phase change temperatures of industrial grade Octacosane and Sodium Acetate Trihydrate were $60.7^{\circ}C$ and $57.4^{\circ}C$, the latent heat were 60.6kcal/kg and 51.1kcal/kg respectively. 2. The latent heat quantity of Octacosane was decreased with the increasing number of phase change cycles. It decreased from 60.6kcal/kg to 47.2kcal/kg upto 200 cycles and then no variation was observed after 200 cycles. 3. To prevent the supercooling of Sodium Acetate Trihydrate, the nucleating agent, Sodium Pyrophosphate Decahydrate of 3 wt% was added, and then the supercooling temperature (Tm-Tsc) was decreased from $25.7^{\circ}C$ to $1^{\circ}C$. The phase separation was disappeared by the addition of CMC-Na of 3 wt% as a thickener. It was found that the optimal quantity of nucleating agent and thickener was 4wt% considering the stability of SAT as a latent heat storage material. 4. The phase change temperature of Sodium Acetate Trihydrate($CH_3COONa{\cdot}3H_2O$) was adjusted from 57.4 to $46.2^{\circ}C$ by the addition of UREA. And then the latent heat quantity was decreased from 51.1 to 38.3kcal/kg. 5. When the heat storage capacities between the sensible and latent heat storage materials were analyzed and compared in heating process from 30 to $90^{\circ}C$, the heat storage capacity of Octacosane was 2.45 times larger than water and 12.5 times than granite at $60.7^{\circ}C$, and the heat storage capacity of Sodium Acetate Trihydrate was 2.53 times larger than water and 12.91 times than granite at $57.4^{\circ}C$.

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