• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.737-744
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• 2007

An experiment was conducted to compare the ME values of imported corns measured by In vivo(TME) and In vitro(MEn, ME and MEpc) methods and to investigate the true amino acid availability(TAAA) and the true nutrient availability(TNA) of imported corns. For TME assay, twenty four 57-weeks-old Hy-Line roosters were assigned to fasting group(4 roosters) and four corn groups(5 roosters each): USA; corn produced in the United States, ARG; corn produced in Argentina, CHN; regular corn produced in China, CHNP; premium corn produced in China. The MEn, ME and MEpc values were determined by equations based on chemical analysis. The TME value of USA(3,745kcal/kg) in as fed basis was significantly (P<0.01) higher than ARG(3,555kcal/kg) and CHNP(3,518kcal/kg) but was not significantly different from CHN(3,671kcal/kg). The TME value of USA(4,144kcal/kg) in DM basis was not significantly different from CHN(4,060kcal/kg) and CHNP(4,008kcal/kg) but was significantly(P<0.05) higher than ARG(4,001kcal/kg). There were significant differences in TAAA of phenylalanine, histidine and arginine among imported corns. Those of USA were highest but overall TAAA was not significantly different among imported corns. True availability of NFE of USA, ARG and CHN was significantly(P<0.05) higher than that of CHNP. However, true availability of crude protein, crude fat, crude fiber and crude ash were not significantly different among corns. The correlation coefficient between TME and MEn value was 0.91 which was significant at P<0.1 but correlation coefficient between TME and ME value and between TME and MEpc value was 0.90 and 0.83, respectively which was not significant at P<0.1. In conclusion, US corn was highest in TME values and Chinese premium corn was not significantly different from regular Chinese corn. The MEn value obtained by equation based on chemical analysis may be used as a tool to evaluate TME value of corn.

• 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 $57.4^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2711-2718
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• 2012

The alkylation of the ambident enolates of a methyl glycinate Schiff base with ethyl chloride was studied at B3LYP and MP2 levels with $6-31+G^*$ basis set. The free (E)-enolates and (Z)-enolate are similar in energy and geometry. The transition states for the alkylation of the free (E)/(Z)-enolate with ethyl chloride have similar energy barriers of ~13 kcal/mol. However, with a lithium ion, the (E)-enolate behaves as an ambident enolate and makes a cyclic lithium-complex in bidentate pattern which is more stable by 11-23 kcal/mol than the (Z)-enolate-lithium complexes. And the TS for the alkylation of (E)-enolate-lithium complex coordinated with one methyl ether is lower in energy than those from (Z)-enolate-lithium complexes by 4.3-7.3 kcal/mol. Further solvation model (SCRF-CPCM) and reaction coordinate (IRC) were studied. This theoretical study suggests that the alkylation of ambident enolates proceeds with stable cyclic bidentate complexes in the presence of metal ion and solvent.

• Journal of the Korean Ceramic Society
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• v.24 no.5
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• pp.417-422
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• 1987

Kinetic studies were made on the thermal decomposition of hydrated magnesium aluminum double sulfate by a nonisothermal TG method. Thermal analyses of the dehydration of tricosahydrate showed that the reaction proceeded via decahydrate to the anhydrous MgAl2(SO4)4 in the range 50$^{\circ}$to 400$^{\circ}C$. Decomposition of MgAl2(SO4)4 occurred as the two-step between 650$^{\circ}$ and 970$^{\circ}C$. Dehydration of MgAl2(SO4)4$.$23H2O and a 2D diffusion controlled with an activation energy of 16.6kcal/mole, respectively. MgAl2(SO4)4 fitted the contracting volume model with an activation energy of 10.5kcal/mole, and MgSO4 fitted a contracting area model with an activation of 4.5kcal/mole.

• Journal of Nutrition and Health
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• v.24 no.2
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• pp.132-141
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• 1991

The purpose of this study was to choose the assessment method of usual energy in take for epidemiological study. Energy intakes of 30 female college students estimated by frequency questionnaires and energy balance method were compared with that obtained by dietary record. The results are summarized as follows. Assessment of mean energy intakes by dietary record frequency questionnaires energy balance method were 156.2Kcal, 1517Kcal, 1878.0Kcal respectively. There was no significant difference between energy intake by dietary record and that by frequency questionnaire. Frequency questionnaire covers 4 weeks energy intake and it can be substituted for dietary record. Although energy intake by energy balance method was significantly different from that obtained by dietary record it shows high correlation with anthropometric and obesity indices and energy expenditure of the subjects.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.69-73
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• 1992

Two experiments were conducted with one-day-old straight run Muscovy ducklings to determine their protein and energy requirements. In the 1st experiment, isoenergetic diets (2800 kcal ME/kg) with three dietary proteins, 18, 20 and 22% in the starter period (1-28 days) and 16, 18 and 20% in the grower and finisher period (29-84 days) were used to determine the optimum protein requirement. While, in the 2nd experiment, isonitrogenous diets (20%, C.P.) with three dietary energy, 2700, 2800 and 2900 kcal ME/kg in the starter period (1-28 days) and (18% C.P.) with 2800, 2900 and 3000 kcal ME/kg in the grower-finisher period (29-84 days) were used to determine the optimum energy requirement. It was observed that 20% C.P. in the starter period and 18% C.P. in the grower and finisher period was adequate for optimum performance, while, 2900 kal ME/kg was sufficient to meet the optimum energy requirement in both the starter, grower-finisher period as regards body weight, feed efficiency, protein efficiency and caloric efficiency are concerned.

• Journal of the Korean institute of surface engineering
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• v.22 no.1
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• pp.10-16
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• 1989

The properties of carburization on Fe-Cr alloys at 900-96$0^{\circ}C$were investiged. The study on carbide layer which had developed during solid-carburizing was made by use of S.E.M, E.PM.A, and X-ray analyzer. The results obtained were summarized as follows, the composition of carbide and the value of activation energy for the growth of carbide layer on each Fe-Cr alloy were 1) Fe-1Cr : M3C and 52Kcal/mole 2) Fe-3Cr and Fe-5Cr : M7C3and 85-88Kcal/mole 3) Fe-7Cr and Fe-9Cr : (M7C3+M23C6)and 55-66Kcal/mole.

• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.69-72
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• 2004

The N-alkylation of 4-aminopyrimidine with a tetrahydro-3-aza-cyclopropa[c]inden-5-one, which is a model reaction of the pharmacophore of duocarmycins, was studied with a quantum chemical method. We consider two factors for the acceleration of the N-alkylation; distortion and protonation of the model pharmacophores. The distortion of the spirocyclopropyl moiety in the model spirocyclopropylcyclohexadienone could induce an intrinsic energy of 3-4 kcal/mol, but the protonation on the carbonyl oxygen of the model cyclohexadienone lowers the transition energy of the N-alkylation of 4-aminopyrimidine dramatically (~46 kcal/mol) and is considered to play a major role in the enzyme reaction. The distorted and protonated spirocyclohexadienone is exothermally relieved to a phenol with the heat of reaction of -37 kcal/mol. The protonation process is proposed to be the mode of action of duocarmycins in the DNA alkylation.

• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.634-641
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• 1998

Quasiclassical trajectory calculations were carried out for the reactions of $H+H_2$ (V=O, J=O) and its isotope variants on the Siegbahn-Liu-Truhlar-Horowitz potential energy surface for the relative energies E between 6 and 150 kcal/mol. The goal of the work was to understand the inter- and intramolecular isotope effects. We examine the relative motion of reactants during the collision using the method of analysis that monitors the intermolecular properties (internuclear distances, geometry of reactants, and final product). As in other works, we find that the heavier the incoming atom is, the greater the reaction cross section is at the same collision energy. Using the method of analysis we prove that the intermolecular isotope effect is contributed mainly by differences in reorientation due to the different reduced masses. We show that above E=30 kcal/mol recrossing also contributes to the intermolecular isotope effect. For the intramolecular isotope effect in the reactions of H+HD and T+HD, we reach the same conclusions as in the systems of $O(^3P)+HD$, F+HD, and Cl+HD. That is, the intramolecular isotope effect below E=150 kcal/mol is contributed by reorientation, recrossing, and knockout type reactions.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.113-122
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• 2003

Net and metabolizable energy requirements for maintenance of Hanwoo (Korean native cattle) bulls were estimated in twenty-eight fasting metabolism trials using seven different feeds at four stages of body weight(100, 200, 300 and 400kg). Three cattle for each of twenty-eight trials fed at a level of maintenance energy requirement were housed in metabolic stalls during the 5 days of collection period. Thereafter, during the 2 days of respiration period the heat production was measured by indirect calorimetry using respiratory chamber. After finishing the respiratory metabolism trials under the maintenance level, experimental animals were fasted for 5 days and were measured heat production by indirect calorimetry using respiratory chamber. Seven different feeds were: 1) mixed ration of concentrate and rice straw, 2) mixed ration of concentrate and mixed grass hay, 3) mixed ration of concentrate and corn silage, 4) rice straw alone, 5) mixed grass hay alone, 6) corn silage alone, 7) concentrate alone. Fasting heat production were 66.05/$W^{0.75}$ at 100kg of body weight and 60~63kcal/$W^{0.75}$ at 200~400kg of body weight. When subtracting heat loss by muscular work from the fasting heat production, basal metabolic rate was 55.92kcal/$W^{0.75}$. The average values of NEm requirements were obtained by adding urinary energy excretion to the basal metabolic rates were 69.1, 62.1, 65.8 and 64.4kcal/$W^{0.75}$ for the four stages of body weight, respectively. The ME requirement for maintenance could be calculated using retained energy and the efficiency of utilization of ME for net energy. The ME requirement for maintenance thus obtained was 102.69kcal/$W^{0.75}$.