• Advances in aircraft and spacecraft science
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• v.11 no.2
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• pp.153-175
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• 2024

In jet engines, turbine blade cooling has an extremely important role. The pin-fin array, which is situated close to the trailing edge of the blade, aids in internal cooling of the gas turbine blades and preserves the structural integrity of the blade. Previous studies often focused on pin-fin configurations, but the current research focuses on improving the geometry at the endwalls to reduce wake vortices behind the pin-fins and enhance heat transfer at the endwalls location. Using the k-ω turbulence model, a numerical study was conducted on a ribbed shape situated on the walls between pin-fin arrays, spanning a Reynolds number range of 7400 to 36000, in order to determine the heat transport characteristics. The heat transfer efficiency coefficient and Nusselt number increase dramatically with the revised wall configuration, according to the numerical data. The channel's heat transfer efficiency is increased by enlarging the heat transfer areas near the pin-fins and by the interaction of the flow with the endwalls. The addition of ribs causes the Nusselt number of the new model to climb from 78% to 96% at the previously given Reynolds numbers, and the heat transfer efficiency index to rise from 60% to 73%. The height (Hr), position (Lr), forward width (Wf), and backward width (Wb) of the ribs are among the geometric elements that were looked at in order to determine how they affected the performance of heat transmission. In comparison to the reference design, the parametric study results demonstrate that the best forward width (Wf/R=18.75%) and backward width (Wb/R=31.25%) increase the heat transfer efficiency index by 0.4% and 1.3%, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.1
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• pp.55-64
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• 2022

The potassium cream soap with fatty acid called cleaning foam has a crystal gel structure, and unlike an emulsion system, it is weak to shear stress and shows characteristics that are easily separated under high temperature storage conditions. The crystal gel structure of cleansing foams is significantly influenced by the nature and proportion of fatty acids, degree of neutralization, and the nature and proportion of polyols. In order to investigate the effect of these parameters on the crystal gel structure, a ternary system consisting of water/KOH/fatty acid was investigated in this study. The investigation of differential scanning calorimeter (DSC) revealed that the eutectic point was found at the ratio of myristic acid (MA) : stearic acid (SA) = 3 : 1 and ternary systems were the most stable at the eutectic point. However, the increase in fatty acid content had little effect on stability. On the basis of viscosity and polarized optical microscopy (POM) measurements, the optimum degree of neutralization was found to be about 75%. The system was stable when the melting point (T_m) of the ternary system was higher than the storage temperature and the crystal phase was transferred to lamellar gel phase, but the increase in fatty acid content had little effect on stability. The addition of polyols to the ternary system played an important role in changing the T_m and causing phase transition. The structure of the cleansing foams were confirmed through cryogenic scanning electron microscope (Cryo-SEM), small and wide angle X-ray scattering (SAXS and WAXS) analysis. Since butylene glycol (BG), propylene glycol (PG), and dipropylene glycol (DPG) lowered the T_m and hindered the lamellar gel formation, they were unsuitable for the formation of stable cleansing foam. In contrast, glycerin, PEG-400, and sorbitol increased the T_m, and facilitated the formation of lamellar gel phase, which led to a stable ternary system. Glycerin was found to be the most optimal agent to prepare a cleansing foam with enhanced stability.

• Journal of Korean Public Health Nursing
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• v.5 no.2
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• pp.53-66
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• 1991

The Purpose of this study is to provide the basic data necessary for the high level of nursing service and the efficiency plan of nurse's man power by analyzing job satisfaction level of public health services. The study population included all public health services(118) in health care center within Jeon Buk province. A Survey was conducted to collect data by a self-administered questionnaire from September I to December B, 1990. A Forty item questionnaire was designed to elicit data concerning how nurses feel about the factors of job satisfaction. All the data were analyzed by means of percentage, mean, anova, T-test, Pearsen's correlation coefficient. The Results of this study were summerized as follows. 1. General characteristics of PHN : age: $33.9\%\;20\~29$ years old education level: $52.6\%$ professional nursing college marital status: $75.5\%$ married religion: $50.5\%$ protestant clinical experience: $40.7\%$ no clinical experience public health nursing career: $47.9\%$ low 5years 2. Influencing factor of Job satisfaction desired duration of employment: $65\%$ needed duration, $18.3\%$ lifetime duration motives of employment: $40.8\%$ no special motive of employment desired organ of leave: $19.3\%$ public health clinic 3. Level of job satisfaction with job satisfaction components. The level of job satisfaction showed an average score 3.39 out of 5.0. Job prestige 4.09 was the highest among the components of Job satisfaction and was presented organizational requirement 3.69, Human relationship 3.66, task requirement 3.36, Autonomy 3.10, pay 2.46. 4. Level of job satisfaction with general characteristics. General characteristics(age, educational level, manital status, clinical experience, public health nursing carrier, duties, lincense and qualification) and job satisfaction was no relationship. 5. Level of job satisfaction with Influencing factor. Duration of desired employment (p<0.01) and motives of employment(p<0.001) was presented. 6. Relationship composing factor of job satisfaction and level of job satisfaction 6 components of job satisfaction was related all of job satisfaction. organizational requirement (r=0.93). Autonomy (r=0.93), Human relationship(r=0.92), task requirement (r=0.90), job prestige (r=0.83), pay (r=0.81)

• Journal of the Korean Society of School Health
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• v.23 no.2
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• pp.286-295
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• 2010

Purpose: This study was conducted to identify the factors affecting the job stress of school nurses and reducing their the job stress by analyzing degree of the stress according to the factors related to job stress. Methods: The participants were 136 school nurses who worked in Pusan province. The Data were collected by self-reporting questionnaires from Dec. 11th in 2006 to Feb. 9th in 2007. The data were analyzed by Frequency, Mean, t-test, ANOVA, Pearson Correlation Coefficient and Stepwise multiple regression analysis (SPSSwin 12.0s). Results: There was significant difference of the degree of job stress in age. There was significantly negative relationship between the job characteristics and job stress (r=-.473), job satisfaction and job stress (r=-.561), personal values and job stress (r=-.429), achievement motivation and job stress (r=-.215) at p<.01 level. The major factor which influence the degree of job stress was job satisfaction. Conclusion: The factors affecting the job stress of school nurses was correlated with one another and influenced to the degree of the job stress directly and indirectly. The factor that affected the degree of the job stress directly was the job satisfaction and the personal values. As shown this result, it is important that the factor of the job stress lies in the mental characteristics.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.207-215
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• 2004

There are various characteristics called for in work roll and intermediate rolls for cold rolling mills. Among these characteristics, the two main requirements are to ensure the quality of the rolled products and to reduce roll cost. To achieve these needs, resistance to wear, to thermal shock and to contact fatigue are especially important. This paper describes that new material(named DSR1) for intermediate rolls which greatly increases rolling campaign and improves resistance to wear has been developed. DSR1 was successfully manufactured and has been used in the cold rolling mill. It showed that Trial product was homogenous in hardness distribution and sufficient usable diameter. Also in service test, trial product is much more excellent rolling performance than conventional $5\%Cr$.

• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.69-77
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• 2008

This study was conducted to know the characteristics of agricultural non-point source pollutants runoff by rainfall events at the upper catchment of Goseong reservoir in Gonjy city, Chungnam Province. For this study, the monitoring sites of the research catchment were set nineteen during the research period (between June 2005 and October 2006). Average runoff coefficient were observed 0.51 in 2005, 0.71 in 2006, respectively. The correlation coefficient (r) between the rainfall and peak-flow was investigated 0.787. By rainfall events, the water quality of the sites were shown like this : BOD 0.555~9.60 mg/L, T-N 0.01~13.50 mg/L, T-P 0.002~2.952 mg/L, and SS N.D~820.0 mg/L. The strong rainfall intensity was the most important factor of the soil erosion. The gabs of the arithmetic mean concentrations and the flow weighted mean concentrations were observed as the followings : BOD 0.0~29.2%, T-N 0.1~11.4%, T-P 0.4~95.2%, and SS 1.7~57.0% in 2005, and BOD 1.0~11.9%, T-N 0.7~7.3%, T-P 9.9~36.5%, and SS 6.6~36.5% in 2006, respectively. The BOD pollution load was 2,117 kg (36% of the total BOD loading of survey periods) while, T-N was 3,209.0 kg (27.9% of the total T-N loading of survey periods), T-P was 136.4 kg (37.4% of the total T-P loading of survey periods) and SS was 72,733.8 kg (51.8% of the total SS loading of survey periods) in the year 2005. In case of 2006, BOD load was 1,321.7, T-N was 2,845.8, T-P was 42.9, and SS was 16,275.8 kg, respectively.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.450-456
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• 2007

This study was carried out investigate the effects of the period of dietary supplementation and the level of fermented mineral feed on daily body weight gain and carcass characteristics of Hanwoo steer. The dietary treatments were compared during two supplementation periods (T1:Feeding Hanwoo steers from 18 months to 25 months, T2: feeding Hanwoo steers from 7 months to 25 months), and the diets tested were of four types (0%: normal concentrate as a basal diet, 1%: 1% addition of fermented mineral feed, 2%: 2% addition of fermented mineral feed, and 3%: 3% addition of fermented mineral feed). A Total of 35 Hanwoo steers were allocated into 7 feeding groups. The daily gain of the 0% fermented mineral feed group was lower (0.64 kg) than that of the other groups (1%: 1.08 kg, 2%: 0.90 kg, 3% treatment: 0.75 kg) for the T1 period, and for the T2 period the order was 1% (0.98 kg) > 0% (0.75 kg) > 1% (0.89 kg). The amount of back fat in decreasing order was as follows: 0% (12.0) > 1% (10.8) > 2% (10.2) > 3% fermented mineral feed (7.8 mm) for the T1 period, and for the T2 period the order was C (16 mm) > T1 (13.8 mm) > T3 treatment (12.6 mm). Eye muscle area increased with increased fermented mineral feed levels. The marbling score of the T1 groups was highest with 3% fermented mineral feed (4.2), and of the T2 groups, the highest score was seen with 1% fermented mineral feed (5.6). Meat color and meat maturity were not different among all groups. The grade of meat quantity and meat quality of both the T1 and T2 groups were highest with the addition of 3% fermented mineral feed. The daily income ranged from 2,062 won to 5,265 won in the T1 groups, which were ordered as follows: 1% > 2% > 3% > 0% fermented mineral feed, and of the T2 groups, the 1% group was highest at 6,098 Won, while the 3% group was lowest at 4,590 Won.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.126-130
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• 1995

$CdS_{1-x}Te_{1-x}$ polycrystalline thin films were fabricated from CdS and CdTe powder by co-evaporation method at $10^{-6}$ Torr. The Optimum evaporation condition was substrate temperature $T_{s}$=$150^{\circ}C$, evaporation time t=30 min. XRD spectrums indicated that the crystal structure chanced from zinc blonde (x$\leq$0.22) to wurtzite (x$\geq$0.96) through mixed structure (0.22$\leq$0.74) as composition value x increase to CdS. Conductive type was n-type by hot point probe method. van der Pauw method was not applicable for x<0,5 due to high hall voltages, Electrical resistivity and Hall carrier mobility were decreased as x increase, while Hall carrier concentration was increased. The optical bandgap of $CdS_{1-x}Te_{1-x}$ polycrystalline thin films measure d at R.T. had quardratic form and the bowing parameter was fitted as 1.98eV for theoretical value of 2.0eV. I-V characteristics of In/CdTe/$CdS_{x}Te_{1-x}$Au Schottky diodes showed that CdS-rich one had better forward characteristics than CdTe-rich one.

• Fire Science and Engineering
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• v.28 no.5
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• pp.98-103
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• 2014

This study investigated the confidence, satisfaction, and psychological safety and identified factors affecting the satisfaction of 41 paramedic students. Data, which consists of pre and post-confidence items on visual analogue scale, 21 satisfaction items and 10 psychological safety items was analyzed using SPSS WIN 21.0 program. After the simulation education, the students were told to write what they felt about the education. Then the students' comments, which were categorized as effectiveness and difficulty, were analyzed. Satisfaction of general characteristics showed a significant difference in age (t = -2.22, p = 0.03) and psychological safety of general characteristics showed a significant difference in gender (t = 3.70, p = 0.00) and age (t = -3.65, p = 0.00). Pre-confidence is low (4.37); however, post-confidence increased to 6.22. It showed a significant difference in pre and post-confidence (t = -5.878, p = 0.000). Satisfaction was correlated with psychological safety (r = 0.516, p = 0.001). The variables affecting satisfaction were psychological safety (t = 3.021, p = 0.005) and post-confidence (t = 1.936, p = 0.061). These variables accounted for 27.6% of the satisfaction according to a regression analysis. The simulation education may be the new effective paramedic education strategy of emergency childbirth. Repetitive simulation learning with further development of various scenarios, more education time, and more faculties will be able to train field compatible paramedics.

• Journal of radiological science and technology
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• v.45 no.1
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• pp.11-17
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• 2022

This study was purpose to quantitative assessment of the resolution characteristics by using American college of radiology(ACR) phantom for magnetic resonance imaging (MRI). The MRI equipment was used (Achiva 3.0T MRI, Philips system, Netherlands) and the head/neck matrix shim SENSE head coil were 32 channels(elements) receive MR coil. And the MRI equipment was used (Discovery MR 750, 3.0T MRI, GE medical system, America) and the head/neck matrix shim MC 3003G-32R 32-CH head coil were receive MR coil. As for the modulation transfer function(MTF) comparison result by using ACR magnetic resonance imaging phantom, the MTF value of the ACR standard T2 image in GE equipment is 0.199 when the frequency is 1.0 mm^-1 and the MTF value of the hospital T2 image in Philips equipment is 0.528. It was used efficiently by using a general sequence more than the standard sequence method using the ACR phantom. In addition it is significant that the quantitative quality assurance evaluation method for resolution characteristics was applied mutatis mutandis, and the result values of the physical image characteristics of the 3.0T MRI device were presented.