• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.7-17
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• 2003

Highly accurate control of an air-fuel ratio is very important to reduce exhaust gas emissions of gaseous-fuel engines. In order to achieve this purpose, a precise engine model is required to estimate engine performance from the engine design process which is applied to the design of an engine controller. Engine dynamics are considered to develop a dynamic engine model of a gaseous-fuel engine. An effective air mass ratio is proposed to study variations of the engine dynamics according to the water vapor and the gaseous-fuel in the mixture. The dynamic engine model is validated with the LPG engine under steady and transient operating conditions. The experimental results in the LPG gaseous-fuel engine show that the estimation of the air flow and the air-fuel ratio based upon the effective air mass ratio is more accurate than that of a normal engine model.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.748-757
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• 2019

The objective of the present study was to evaluate effects of probiotic mixture (PM) including Bacillus subtillus, Streptomyces galilaeus and Sphingobacteriaceae on egg production, egg quality, and eliminating odor in laying hens. A total of 240 Hy-Line Brown laying hens (50 wks of age) were divided into four treatment groups (60 replicates of birds, each) in completely randomized design. Groups were assigned to four experimental diets: CON (a basal diet of no PM additive as control), basal diet supplemented with either CP3 (0.3% commercial probiotics), PM3 (0.3% PM), or PM5 (0.5% PM 0.5). Data of egg production and egg quality were obtained during 6 weeks of experimental period. Egg production, Haugh unit, shell thickness, breaking strength, yolk color, and albumin high were significantly increased in CP3 and PM3 compared to those in CON and CP3. Ammonia levels and numbers of E. coli, total aerobic bacteria, Coliform, and Salmonella in feces were significantly increased in order of CON>CP3>PM3>PM5. The present study indicates that addition of 0.3% probiotic mixture including B. subtillus, S. galilaeus and Sphingobacteriaceae to diets may improve egg production, egg quality, and eliminate fecal ammonia of laying hens.

• Journal of muscle and joint health
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• v.26 no.1
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• pp.15-26
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• 2019

Purpose: The purpose of this study was to develop a Dongsasub training applying aroma necklace for nursing students in clinical practicum, and to evaluate the training programs' effects on perceived stress, self-esteem, depression, and clinical competence of the participants. Methods: This study used a cluster-randomized controlled trial design. Participants were 56 nursing students taking clinical practicum courses (26 in the experimental group and 30 in the control group). The training program consisted of four sessions of Dongsasub training and wearing a necklace where a mixture of aroma oils attached. Participants in experimental group were given a necklace with essential oil mixture of lavender, bergamot, and geranium with the ratio of 1:1:1 for 2 weeks. The control group received no intervention. Outcome variables included perceived stress, self-esteem, depression, and clinical competence. Data were analyzed with Fisher's exact test, Chi-square, Independent t-test using the SPSS/WIN 21.0. Results: Independent t-test revealed that perceived stress (t=3.15, p=.003), depression (t=4.62, p<.001) were significantly lower in the experimental group than the control group; self-esteem (t=-3.03, p=.004), clinical competence (t=-2.15, p=.036) scored significantly greater than the control group. Conclusion: The results indicate that the Dongsasub training with application of the aroma necklace can be used as an effective nursing intervention for lowering perceived stress, depression and improving self-esteem, clinical competence of nursing students.

• Ocean and Polar Research
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• v.26 no.4
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• pp.647-653
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• 2004

Experimental studies with 4.3m and enlarged 30m in height have been conducted to investigate the flow characteristics of solid-liquid mixture in a lifting pipe and to acquire the design data for sea tests that will be performed in the future. From the results, it was observed that the more the discharged volume fraction and the solid diameter increase, the more the hydraulic gradient increases. Also, the more the diameter of the lifting pipe increases, the smaller the friction loss, and consequently, the less pressure drop and hydraulic gradient. From the enlarged hydraulic pumping experiments, it was shown that the results of the experiments were matched with those of the numerical model previously developed. On the bases of these studies, we plan to conduct further experiments and validate the hydraulic pumping model.

• Journal of Ginseng Research
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• v.46 no.2
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• pp.283-289
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• 2022

Background: Sarcopenia, defined as loss of muscle mass and strength with age, becomes a public health concern as the elderly population increases. This study aimed to determine whether the mixture of soluble whey protein hydrolysate (WPH) and Panax ginseng berry extract (GBE) has a synergetic effect on sarcopenia and, if so, to identify the relevant mechanisms and optimal mixing ratio. Methods: In the first experiment, C57BL/6 mice were hindlimb immobilized for one-week and then administered WPH 800 mg/kg, GBE 100 mg/kg, WPH 800 mg/kg+ GBE 100 mg/kg mixture, and Fructus Schisandrae extract (SFE) 200 mg/kg for two weeks. In the second experiment, experimental design was same, but mice were administered three different doses of WPH and GBE mixture (WPH 800 mg/kg+ GBE 100 mg/kg, WPH 800 mg/kg+ GBE 90 mg/kg, WPH 1000 mg/kg+ GBE 75 mg/kg). Results: In the first experiment, we confirmed the synergetic effect of WPH and GBE on muscle mass and identified that GBE was more effective on the protein synthesis side, and WPH tended to be slightly more effective for protein degradation. In the second experiment, among three different ratios, the WPH 800 mg/kg+ GBE 100 mg/kg was most effective for muscle mass and strength. The mixtures activated muscle protein synthesis via PI3K/Akt/mTORc1 pathway and inhibited muscle protein degradation via suppressing ubiquitin-proteasome system (UPS) and autophagy-lysosome system (ALS), and these effects were more GBE dose-dependent than WPH. Conclusion: The WPH and GBE mixture having a synergetic effect is a potential agent to prevent sarcopenia.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.1
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• pp.83-89
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• 2011

A design plan was proposed for determining combustor configuration of regenerative- cooled liquid rocket engine in the process of preliminary design. Rocket performance and regenerative cooling results were calculated using the properties of combustion gas estimated in CEA. For required thrust, chamber pressure, atmosphere pressure and propellant mixture ratio the mass flow rate of propellants and combustor performance were predicted by one-dimensional and experimental correlations. Finally, determinable plan for the contour of combustor were presented through Rao nozzle design method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.37-42
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• 2010

A design plan was proposed for determining combustor configuration of regenerative- cooled liquid rocket engine in the process of preliminary design. Rocket performance and regenerative cooling results were calculated using the properties of combustion gas estimated in CEA. For required thrust, chamber pressure, atmosphere pressure and propellant mixture ratio the mass flow rate of propellants and combustor performance were predicted using one-dimensional and experimental equations. Finally, determinable plan for contour of combustor were presented through Rao nozzle design method.

• Journal of Korean Academy of Nursing
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• v.38 no.4
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• pp.493-502
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• 2008

Purpose: The purpose of this study was to examine the effects of aroma hand massage on pain, state anxiety and depression in hospice patients with terminal cancer. Methods: This study was a nonequivalent control group pretest-posttest design. The subjects were 58 hospice patients with terminal cancer who were hospitalized. Twenty eight hospice patients with terminal cancer were assigned to the experimental group (aroma hand massage), and 30 hospice patients with terminal cancer were assigned to the control group (general oil hand massage). As for the experimental treatment, the experimental group went through aroma hand massage on each hand for 5 min for 7 days with blended oil-a mixture of Bergamot, Lavender, and Frankincense in the ratio of 1:1:1, which was diluted 1.5% with sweet almond carrier oil 50 ml. The control group went through general oil hand massage by only sweet almond carrier oil-on each hand for 5 min for 7 days. Results: The aroma hand massage experimental group showed more significant differences in the changes of pain score (t=-3.52, p=.001) and depression (t=-8.99, p=.000) than the control group. Conclusion: Aroma hand massage had a positive effect on pain and depression in hospice patients with terminal cancer.

• Women's Health Nursing
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• v.15 no.4
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• pp.372-380
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• 2009

Purpose: The purpose of this study was to examine the effects of aroma hand massage on Sleep, depression and quality of life in the institutionalized elderly women. Methods: This study was a nonequivalent control group pretest-posttest design. The data was collected from June 23 to August 10 of 2009. Fifty - Six elderly women were divided into two groups, 27 institutionalized elderly women for the experimental group and 29 institutionalized elderly women for the control group. As for experimental treatment, the experimental group went through aroma hand massage with blended oil-a mixture of Lavender, Bergamot, Chamomile Roman in the ratio of 1 : 1 : 1, which was diluted 2.0% with jojoba carrier oil 20mL-on each hand for 5 minutes, three times a week during two weeks. Control group went non-treatment. Results: The aroma hand massage experimental group showed more significant differences in the charge of sleep score (t=3.83, p=.00) and depression (t=-3.54, p=.00). Conclusion: Aroma hand massage had a positive effect on sleep and depression in Institutionalized elderly women.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.317-324
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• 1999

This study was conducted to evaluate the dry matter yield and quality of mixture swards associated with Festulolium braunii(Festuca pratensis Huds. ${\times}$ Lolium multiflorum Lam.). The experiment was arranged in a randomized block design with four mixture types: A(control); orchardgrass(seeding rate 60%) + tall fescue 20% + Kentucky bluegrass 10% + white clover 10%, B; orchardgrass 60% + tall fescue 20% + Festulolium braunii 10% + white clover 10%, C; orchardgrass 60% + Festulolium braunii 20% + Kentucky bluegrass 10% + white clover 10%, and D; orchardgrass 30% + Festulolium braunii 30% + red clover 40%. This study was carried out from Sept. 1996 to Dec. 1998 at Chungnam National University. The DM yield of D mixture type was higher than that of other mixture types(P<0.05). Compared with A(control) mixture type, the DM yield of the B mixture type which substitutes Kentucky bluegrass with Festulolium braunii was higher, but the C mixture type which substitutes tall fescue with Festulolium braunii was lower than that of A(control) mixture type. The content of CP, NDF, ADF, hemi-cellulose and cellulose among mixture types shows no significant differdence. Howerever, the DMD was not significantly different among mixture types in 1997, but the DMD of C and D mixture type were significantly higher than those of other mixture types in 1998(P<0.05). On the otherhand, the yield of CP and DDM in D mixture types was higher than those of the other mixture types(P<0.05). In botanical composition, the Festulolium braunii percentage of B, C and D mixture type with mixed Festulolium braunii wasd highly maintained, especially D mixture type was ranging from 40% to 60% in experimental periods. Following the above result, It is the most favorable mixture method for Festulolium braunii to make use of top grass like orchardgrass + red clover. It is also recommened to substitute bottom grass like Kentucky bluegrass with Festulolium braunii rather than with tall fescue in A(control) mixture type.