• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.837-845
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• 2002

Based on ab initio calculations at the MP2(FULL)/6-31+G**//RHF/6-31G** level, we compare the energetic and mechanistic features of a model reaction for catalytic action of Δ?-3-ketosteroid isomerase (KSL,E.C.5.3,3.1) with those of a corresponding nonenzymatic reaction in aqueous solution. The results show that the two catalytic acid residues,Tyr14 and Asp99, can lower the free energy of activation by 8.6kcal/mol, which is in good agreement with the experimentally predicted~9 kcal/mol,contribution of electrophilic catalyses to the whole enzymatic rate enhancement. The dienolate intermediate formed by proton transfer from the substrate carbon acid to the catalytic base residue (Asp38) ins predicted to be stabilized by 12.0 kcal/mol in the enzymatic reaction, making its formation thermodynamically favorable. It has been argued that enzymes catalyzing the reactions of carbon acids should resolve the thermodynamic problem of stabilizing the enolate intermediate as well as the kinetic porblem of lowering the free energy of activation for porton abstraction. We find that KSI can successfully overcome the thermodynamic difficulty ingerent in the nonenzymatic reaction through the electrophilic catalyses of the two acid residues. Owing to the stabilization of dienolate intermediate, the reketonization step could influence the overall reaction rate more significantly in the KSI- catalyzed reaction than in the nonenzymatic reaction, further supporting the previous experimental findings. However, the electrophilic catalyses alone cannot account for the whole catalygic capability (12-13 kcal/mol), confiming the earlier experimental implications for the invement of additional catalytic components. The present computational study indicates clearly how catalytic residues of KSI resolve the fundamental problems associated with the entropic penalty for forming the rate-limiting transition state and its destabilization in the bulk solvation environment.

• Journal of the Korean Dietetic Association
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• v.16 no.3
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• pp.270-278
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• 2010

We examined whether visual perception related to consumption norms could influence food consumption and satiety by using modified soup bowls with elevated bottoms. Twenty-six healthy women (BMI 19.9 $kg/m^2$ Age 24 yr) participated in the study once a week for 2 weeks. The subjects were served beef shank soup in one of two soup bowls (180 g soup in the modified bowl or 250 g soup in the normal bowl). The results showed that subjects who ate from the modified soup bowl consumed less soup (135.3 kcal vs 180.0 kcal, P<0.001) and had lower total energy intake (390.6 kcal vs 438.1 kcal, P<0.01) than those who ate from the normal soup bowl. However, despite consuming fewer calories, satiety levels of those who ate from the modifed soup bowl were not significantly different from those using the normal soup bowl. In conclusion, these results indicate that the modified soup bowl which created a distorted visual perception ot the amount of soup in the bowl leads to decreased soup intake and total energy intake without altering satiety. The reduced amount of soup in the modified soup bowl may also implicitly suggest what might be interpreted as an appropriate amount to consume, and also in essence suggest reduced consumption norm.

• Applied Biological Chemistry
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• v.26 no.1
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• pp.47-52
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• 1983

The size distribution and changes of volume and grain hardness of ‘Sedohadaka', waked barley of various polishing yields during hydration process at various temperatures were investigated, and were analyzed kinetically, Both major and minor diameter of barley grain decreased linearly during polishing, and the decreasing rate of major diameter was greater than that of minor diameter. The volume change of barley grain could be expressed as a power of hydration time, and a break point was found in case of non-polished barley. The changing rate of grain hardness followed the equation of a first-order reaction, and the reaction rate constant increased with decreasing polishing yields and at higher temperature in the range of $20{\sim}60^{\circ}C$. The activation energy of hardness change reaction of polished barley during hydration were ranged $5.1{\sim}7.8Kcal/mole$, and 13.3Kcal/mole of non-polished barley.

• Journal of the Korean institute of surface engineering
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• v.26 no.2
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• pp.87-107
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• 1993

The grain size of the final products of WC-Co and WC-Ni composite powders is dependent on the size of the starting material and the conditions employed for the reduction and carburization. APT-Co and -Ni com-plex salts were prepared by the substitution reaction between ammonium ions in APT and the metal ions in Co(NO3)2 and Ni(NO3)2 solutions of different concentrations(0.1 to 0.7M) at $50^{\circ}C$ and the grain sizes of the com-plex salts was $0.54~0.76\mu\textrm{m}$. The complex which calcined the complex salts at $700^{\circ}$~80$0^{\circ}C$ for 60min. were 0.2~0.5$\mu\textrm{m}$. W-Co($5.92^{\circ}C$) and -Ni(6.95%) powders which reduced the complex oxides with H2d atmo-sphere(flow rate;600cc/min.) at $700^{\circ}$~$800^{\circ}C$ for 60min. were $0.5~0.6\mu\textrm{m}$. The mean grain sizes of WC-Co and WC-Ni composite powders which carburized both complex metals of W-Co and W-Ni at $800^{\circ}C$ for 60min. were $0.5~0.6\mu\textrm{m}$, and take place the coarsening of the grain above $800^{\circ}C$ and the optmium ratio of C3H8 and H2 was 0.2 for the control of the free carbon. The effect of Co contents on the particle sizes decreased from 0.4 to $0.25\mu\textrm{m}$ with increasing the content from 2.0 to 7.6w%. The activation energies on the reductions of oxides and the formations of carbides were as follows ; W-Co : Q = 8.7 kcal/mole, W-Ni : Q = 8.1 kcal/mole, WC-Co pow-der : Q = 17.8 kcal/mole, WC-Ni powder : Q = 16.6 kcal/mole.

• Research in Community and Public Health Nursing
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• v.14 no.1
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• pp.95-105
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• 2003

Purpose: This study was conducted to analyze occupational and leisure-time physical activity(LTPA) in male office workers and to examine factors related to LTPA. Method: The subjects for this study were 226 male office workers, from eight work places located in Seoul, who had no physical restrictions. Minnesota LPTA Questionnaire (Taylor et al., 1978) revised by Kim(1997) was used to measure LTPA and revised Tecumseh Occupational Physical Activity Questionnaire (Motoye, 1971) was used to measure occupational physical activity. The data were collected from May 4 to May 19, 2001 using a semi-structured questionnaire with interviews and self reports. The collected data were analyzed using SPSS Windows 10.0 Program. Results: The results of this study are summarized as follows. 1. The mean level of physical activity was 8,716.9kcal/wk. The occupational physical activity was at 6,605kcal/wk(75.8%) and the level of LTPA was 2,111.4kcal/wk (24.2%). 2. Using 2,000kcal/wk as a base for categorizing LTPA as active or inactive, it was found that there were 94 subjects(41.6%) in the active group. 3. Subjects in their thirties had a lower level of LTPA than subjects in other age groups (F=3.484, p<.05). Physical activity, self-efficacy (r=.405, p=.000) and perceived health status (r=.301, p=.000) were positively related to LTPA. 4. Participants in club activities had a higher level of LTPA than those who did not (t=-2.369, p=.020). Support for physical activity(r=.164, p=0.13) was positively related to LTPA. Conclusion: This study suggested that to increase physical activity in male office workers, physical activity promotion programs should be established according to age and sex especially for those who are in their thirties and for women, and should include strategies strengthening support through peer groups and family, developing club activities and increasing physical activity self-efficacy.

• Journal of the Korean Chemical Society
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• v.36 no.3
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• pp.366-375
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• 1992

The aminolysis of carbamates are studied MO theoretically using AM1 method. The results indicated that the reactivity is determined by bond-making and-breaking and steric effects; as a result the $B_{AC}2$ mechanism is favored due to favorable contribution of bond formation in agreement with experimental results. We found that although thermal 2＋2 reaction is forbidden, it becomes allowed when the total electrons involved are six in a four-center reaction and proceeds by a consecutive onestep mechanism. Comparison of activation barriers show that greater energy is required in breaking a sigma bond compared with the energy required for breaking a $\pi$ bond, by 17 kcal/mol and the six membered ring structure is favored about 5 kcal/mol sterically.

• Journal of the Korean Dietetic Association
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• v.14 no.4
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• pp.396-403
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• 2008

We attempted to determine whether energy density would influence calorie intake via cognitive cues, as reflected by satiety. This experiment was designed using two different energy density levels of Kimbab: normal Kimbab (1.6 kcal/g) vs low-density Kimbab (1.0 kcal/g). 26 female college students participated in this study. The subjects ate Kimbab in the lab once a week for 2 weeks. Each week at noon, they were served 24 units of either normal or low-density Kimbab, and we determined the units, grams, and calories of the real & cognitive intake of Kimbab, and also analyzed the satiety rate after eating Kimbab. Our results demonstrated that the real calorie intake from the low-density Kimbab was significantly lower than that of the normal Kimbab (290.3 kcal vs 474.4 kcal, p<0.001), but we noted no significant differences in the units and grams of real and cognitive intake between the normal and low-density Kimbab. However, despite consuming 39% lower caloric intake, the subjects reported similar levels of satiety rates with the two different density levels of Kimbab, as they did not perceive themselves to have eaten more normal Kimbab than low-density Kimbab. Thus, this study provides evidence that the energy density of food is a crucial determinant of caloric intake, and supports the notion that the consumption of low energy-dense foods may result in a reduction of caloric intake without altering satiety.

• Korean Journal of Food Science and Technology
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• v.13 no.4
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• pp.328-333
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• 1981

As a step to investigate energy conservation in canneries, energy consumption pattern and energy usages of various unit operations in a mushroom cannery were examined. The results are as follows; 1. In the mushroom cannery, fuel oil and electricity were used mainly for temperature control of mushroom growing house in winter and various cultivation operation respectively. To grow and process 1 kg of mushroom, thermal energy of 4634 kcal and electrical energy of 0. 116 kwh were consumed. About 80% of all energy was consumed for cultivation. 2. Steam qualities at each respective processing line were $92{\sim}94%$, giving no great differences among lines. 3. As a direct energy in 1 day processing operations of 8 tons of mushroom, thermal energy of $301.5{\times}10^{4}kcal$ and electrical energy of 60.1 kwh were used. The energy intensive operations were blanching (35%) and retorting (38%).

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.12-17
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• 1987

Physicochemical properties and gelatinization kinetics of Ol barley starch were studied. The granule size was $13-28\;{\mu}$ and the granule shape was oval or circular. Also, Ol barley starch had amylose content of 32%. Swelling power and solubility reached to the maximum values of 7.22 and 2.28% at the gelatinization temperature of $90^{\circ}C$. The pasting temperature of starch was slightly higher than those of powder and defatted powder. Most of the increase in light penetration was accomplished from the gelatinization temperature of $80^{\circ}C$ to $90^{\circ}C$. The gelatinization reaction of lL barley starch occurred in 2 stages. The activation energy of lst stage gelatinization reaction was 23.84 kcal/mole, whereas activation energies of 2nd stage gelatinization reaction were 33.38 and 72.82 kcal/mole around $80^{\circ}C$.

• Resources Recycling
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• v.26 no.2
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• pp.25-32
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• 2017

Since the heating values of swine manures were very low at 859~1,075 kcal/kg, it was necessary to convert to carbonization residue by carbonization processes among thermal processes. The most important factor in the carbonization process of swine manure is the carbonization temperature, and it was evaluated the optimal range of carbonization temperature for swine manure in this study by the thermal characteristics and the reaction kinetics. The carbonization of swine manure could be described by the 1st order reaction and Arrhenius equation. The frequency factor (lnA) and the activation energy were estimated to be 3.05~13.08 and 6.94~18.05 kcal/mol, respectively. The range of optimal carbonization temperature range of swine manure was $260{\sim}300^{\circ}C$.