• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.582-590
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• 2007

In view of the analysis of the phenomena and the prediction of the performance, mathematical modelling and simulation of a high temperature pilot reactor for water gas shift reaction (WGSR) has been carried out. Multiscale simulation incorporated computational fluid dynamics (CFD) technique, which has the capability to deal with the reactor shape, fluid and energy transport with extensive degree of accuracy, and process modeling technique, which, in turn is responsible for reaction kinetics and mass transport. This research employed multiscale simulation and the results were compared with those from process simulation. From multiscale simulation, the maximum conversion of was predicted approximately 0.85 and the maximum temperature at the reactor was calculated 720 K, resulting from the heat of reaction. Dynamic simulation was also performed for the time transient profile of temperature, conversion, etc. Considering the results, it is concluded that multiscale simulation is a safe and accurate technique to predict reactor behaviors, and consequently will be available for the design of commercial size chemical reactors as well as other commercial unit operations.

• Korean Journal of Agricultural Science
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• v.44 no.1
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• pp.67-76
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• 2017

Fermented Rhus verniciflua (FRV) as feed additives act as excellent anti-diarrheal drugs as they increase the intestinal absorption rate therefore being indirectly associated with enhancing growth performance and increasing digestibility in livestock. A total of 80 weaned pigs with an average initial body weight (BW) of $6.82{\pm}1.11kg$ were used to evaluate a diet supplemented with FRV meal in a 6 week feeding trial with two dietary treatments [CON - basal diet; TRT - CON + 0.2% FRV] on growth performance, apparent total tract digestibility (ATTD), blood profiles, fecal microflora, and fecal score. Our results showed that the dietary supplementation of FRV improved (p < 0.05) average daily gain and gain : feed (G : F) ratio during days 15 - 42 and the overall experiment period and also increased the ATTD of dry matter (p < 0.05) at days 14 and 42. On the contrary, there was no effect (p > 0.05) on average daily feed intake, ATTD of nitrogen and energy, and blood profiles during the entire experiment. Moreover, dietary inclusion of FRV significantly increased fecal Lactobacillus (p < 0.05) counts and reduced the diarrhea during days 22 - 42. Thus, the results suggest that FRV can be used as a potential additive to improve growth performance and dry matter and to reduce diarrhea while having beneficial effects on fecal microflora in weanling pigs.

• Korean Journal of Agricultural Science
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• v.44 no.1
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• pp.77-85
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• 2017

A total of 120 weaning pigs [(Landrace ${\times}$ Yorkshire) ${\times}$ Duroc] with an average body weight of $8.95{\pm}0.88kg$ were used in this study to investigate the influence of supplementation of combined flavor and sweetener. The diets included: 1) TRT1, basal diet, 2) TRT2, TRT1 + 500 mg/kg flavor, 3) TRT3, TRT1 + 150 mg/kg sweetener, and 4) TRT4, TRT1 + 500 mg/kg flavor + 150 mg/kg sweetener. The TRT4 treatment produced a higher average daily gain (ADG) than that in the other treatments on d 0 - 14 and the whole experimental period (p < 0.05). The TRT1 and TRT2 treatments gave a lower average daily feed intake (ADFI) than that of TRT4 on d 0 - 14 and d 0 - 42 (p < 0.05). On d 15 - 42, TRT4 had a higher ADFI than that of TRT1 (p < 0.05). Compared to TRT1, dry matter (DM), gross energy (GE), and nitrogen (N) digestibility increased in pigs fed the TRT4 diet (p < 0.05) on d 14. Serum norepinephrine concentration in TRT1 treatment was higher (p < 0.05) than that in TRT4 treatment at 72 h after weaning. On d 0 - 7, diarrhea score decreased in TRT4 treatment compared with TRT1 and TRT2 treatments. In conclusion, flavor and sweetener complex addition improved ADG and ADFI as well as DM, N, and GE digestibility in weanling pigs. This supplementation in pigs' diets decreased the serum norepinephrine concentration at 72 h after weaning and the diarrhea score during the first week of weaning.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.1
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• pp.1-10
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• 2007

The effects of mulberry-leaf powder Tofu(MPT) on anthropometric measurements, including bone mineral density(BMD) in the right carpus, biochemical bone turnover markers, serum levels of lipids and macrominerals, were investigated in 30 smoking male adults who lived in Choongnam were given MPT(100 g/day) for 4 weeks. The average ages, number of smoked cigarettes and packyear were 22.38 years, 15.12/day and 3.54 years, respectively. The nutrient contents per 100 g MPT were 86.10 kcal energy, 8.98 g protein, 0.53 mg fiber, 211.33 mg Ca and 1.59 g fat. Anthropometric measurements, including dietary intake using the 24-hours recall method, carpal BMD using DEXA, serum levels of protein, albumin and glucose, lipid profiles (cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol) with Al(atherosclerosis index), HTR, CRF, LHBt, some biomarkers of BMD(serum alkaline phosphatase activity, osteocalcin, urinary DPD), and serum macrominerals(Ca, Ca/P ratio, Mg) and Pb were analyzed before and after consumption of MPT. After MPT consumption, dietary intakes of plant protein, total Ca and plant Ca increased significantly, but there were no significant differences in anthropometric measurements, BMD with bone metabolism markers, serum levels of protein, albumin or glucose, lipid profiles with AI, HTR, LHR and CRF.

• Journal of the Korean Dietetic Association
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• v.12 no.3
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• pp.289-298
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• 2006

We studied the effects of intake of the steamed bean powder(SB) and chungkukjang powder(CK) on blood parameters such as glucose, albumin, GOT, GPT, hematocrit, hemoglobin, total-/HDL-/LDL-cholesterol and triglyceride, and blood antioxidant nutrients such as retinol, tocopherols and carotenes in 26 college women. There were 2 groups, one group had 13 participants who consumed 30g SP and second group (13 participants) consumed 30g CK daily for 4 weeks. The study compared before with after SP/CK intake. The average age of the participants was 22.1 years, there were no significant differences between the two groups in terms of all parameters before the study. The energy intake showed no significant differences between before and after SP/CK intake. C(carbohydrate) propotion was reduced, and P(protein) and F(fat) ratio were increased after 4 week intake of SP/CK. Indices of nutritional quality(INQ) of protein(p<0.01), iron(p<0.05), zinc(p<0.05), vitamin C(p<0.05) were significantly increased after SP intake, and those of protein(p<0.05) and zinc also increased after CK intake. There were no significant differences in TG, total-/HDL-/LDL-cholesterol before and after SP/CK intake. The CK intake group showed the reduction only in retinol level in blood(p<0.05). Some students reported the improvement of the constipation and the regularity of the bowel elemination, and some students experienced the prolongation effects on one's monthly days after SP/CK intake. In this study, we could see the effect of improvement in some nutrients intake, but no effect in blood parameters by SP/CK intake for 4 weeks. That reason might be that the participants were healthy young women, or the trail period was not enough long to change.

• Korean Journal of Community Nutrition
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• v.23 no.5
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• pp.411-423
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• 2018

Objectives: The purpose of this study was to develop new meal planning tools for a nutritionally balanced diet. Methods: Based on the food exchange list for diabetes, we adjusted the food group classification system to reflect the suggested nutritional factors for chronic disease prevention and health promotion. We developed a nutritionally balanced dietary profile for adults and compared it with the dietary reference intakes for Koreans (KDRIs) and the food pattern recommended by the Korean Diabetes Association. Results: The newly developed menu planning tools are the LOHAS food exchange table and the LOHAS food pattern. Our recommended daily 1,800 kcal dietary composition for adults is as follows: The carbohydrate food group consists of 4 'whole grains', 3 'refined grains', 2 'sugars', 9 'vegetables', 3 'starchy vegetables', 2 'fruits' and 1 'high sugar fruits'. The protein food group includes 3 'plant protein foods', 3 'animal protein foods (low-fat)', and 1 'animal protein foods (high-fat)'. The fat food group consists of 2 'oils and nuts' and 1 'solid fats'. The total number of calories is estimated at 1,840 kcal and the energy ratio is 62% carbohydrate, 18% protein, 20% fat, 6.8% saturated fat and 13.2% sugars. Using the LOHAS food exchange table, it is possible to estimate values of saturated fat, unsaturated fat, dietary fiber, and sugars besides carbohydrate, protein and fat. It is also possible to compose a dietary design considering carbohydrate, sugars, saturated fat and dietary fiber. The LOHAS food pattern provides benefits for the management of both institutional food services and individual meals, as it can help reduce the levels of saturated fat and sugar intake and help develop healthy meals rich in unsaturated fats and dietary fiber. Conclusions: The LOHAS food exchange table and LOHAS food pattern are expected to be practical tools for designing and evaluating nutritionally balanced diets.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.2
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• pp.94-102
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• 2009

Conceptual design of scroll expander and scroll compressor for 10kW-class Stirling engine utilizing solar energy as heat source has been carried out to estimate the applicability of scroll mechanism for Stirling cycle. CO2 was chosen as working fluid, since it has lower expansion index and higher density among probably usable gases. Gas temperature at the expander inlet was set at $700^{\circ}C$, and that at the compressor inlet was at $40^{\circ}C$. System efficiency reached maximum at the pressure ratio of about 2.5, and the peak efficiency increased with increasing high side pressure. Due to safety concern, the pressure condition of 6 MPa/2.5 MPa was chosen as design condition. Orbiting scroll members for the expander and compressor were designed to have double-sided structure in order to reduce the overall scroll size and to cancel out the axial gas forces acting on the orbiting scroll base plate. By parametric study on the scroll profile, smaller possible size for the scroll members was obtained. With the shaft speed of 3600rpm, the shaft output of the designed scroll expander was calculated to be 45.4kW, while input power for the scroll compressor was 34.5kW, yielding 10.9kW for the output power of the Stirling engine. System efficiency was estimated to be about 7.3%, and overall efficiencies of the scroll expander and compressor were around 84.1% and 88.3%, respectively.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.1
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• pp.28-36
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• 1996

The influence of vertical eddy viscosity to the nonlinear interaction of tidal current and wind-induced current is examined using a point model. A zero-equation turbulence model is derived by simplifying the q$^2$-q$^2$1 turbulence model under the assumption that the generation of turbulence kinetic energy is balanced with its dissipation and is further modified to include the depth of frictional influence properly The zero-equation turbulence model is derived and the possibility of resonance in the presence of Coriolis effect is suggested. The amplitudes of tidal currents remain the same regardless of the applied wind stress, but the over-tide component is generated due to the nonlinear interaction of tidal current and wind-induced current. Significant changes in the vertical profile of wind-induced currents can occur according to tide-induced background turbulence. The turbulence model can give rise to misleading results when applied to the wind-driven circulation in the tide-dominated sea such as Yellow Sea unless the tide-induced background turbulence is adequately included in the parameterization of vertical eddy viscosity.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.8
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• pp.1340-1346
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• 2016

Utilization of Distributed Generations (DGs) using Renewable Energy Sources (RESs) has been constantly increasing as they provide a lot of environmental, economic merits. In spite of these merits, some problems with respect to voltage profile, protection and its coordination system due to reverse power flow could happen. In order to analyze and solve the problems, accurate modeling of DG systems should be preceded as a fundamental research task. In this paper, we present a PhotoVoltaic (PV) generation system which consists of practical PV cells with series and parallel resistor and an inverter for interconnection with a main distribution system. The inverter is based on controllable current source which is capable of controlling power factors, active and reactive powers within a certain limit related to amount of PV generation. To verify performance of the model, a distribution system based on actual data is modeled by using ElectroMagnetic Transient Program (EMTP) software. Computer simulations according to various conditions are also performed and it is shown from simulation results that the model presented is very effective to study DG-related researches.

• Preventive Nutrition and Food Science
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• v.17 no.2
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• pp.93-100
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• 2012

The purpose of this study was to identify food sources for major minerals such as calcium (Ca), phosphorus (P), sodium (Na) and potassium (K), and to evaluate the relationship between dietary intake of these minerals and serum lipids in healthy Korean adults. A total of 132 healthy men and women completed a physical examination and dietary record and provided blood samples for lipid profile analysis. Results showed the following daily average mineral intakes: 373.4 mg of calcium, 806.0 mg of phosphorous, 3685.8 mg of sodium, and 1938.3 mg of potassium. The calcium-to-phosphorus and sodium-to-potassium ratio was about 0.5 and 2.0, respectively. The primary sources for each mineral were: vegetables (24.9%) and fishes (19.0%) for calcium, grains (31.4%) for phosphorus, seasonings (41.6%) and vegetables (27.0%) for sodium, and vegetables (30.6%) and grains (18.5%) for potassium. The correlation analysis, which has been adjusted for age, gender, total food consumption, and energy intake, showed significantly positive correlations between Ca/P and serum HDL cholesterol levels, between Na intake and the level of serum total cholesterol, and between Na/K and the level of serum cholesterol and LDL cholesterol. Our data indicates that the level of mineral consumption partially contributes to serum lipid profiles and that a diet consisting of a low Ca/P ratio and a high Na/K ratio may have negative impacts on lipid metabolism.