• 한국재료학회지
• /
• 제27권8호
• /
• pp.409-415
• /
• 2017

For enhanced cavitation erosion resistance of vessel propellers, an electroless Ni-P plating method was introduced to form a coating layer with high hardness on the surface of Cu alloy (CAC703C) used as vessel propeller material. An electroless Ni-P plating reaction generated by Fe atoms in the Cu alloy occurred, forming a uniform amorphous layer with P content of ~10 wt%. The amorphous layer transformed to (Ni3P+Ni) two phase structure after heat treatment. Cavitation erosion tests following the ASTM G-32 standard were carried out to relate the microstructural changes by heat treatment and the cavitation erosion resistance in distilled water and 3.5 wt% NaCl solutions. It was possible to obtain excellent cavitation erosion resistance through careful microstructural control of the coating layer, demonstrating that this electroless Ni-P plating process is a viable coating process for the enhancement of the cavitation erosion resistance of vessel propellers.

• 한국환경과학회지
• /
• 제27권10호
• /
• pp.875-881
• /
• 2018

To select fruit trees suitable for shaded urban garden with Elaeagnus umbellata var. coreana, Malus domestica 'Alps Otome', Malus domestica 'Fujii', Prunus mume, Prunus persica for. persica, Rubus fructicosus, and Vaccinium corymbosum 'Reka', leaf growth in response to different light was investigated two years after 35% shade treatment. Leaf area of E. umbellata var. coreana, M. domestica 'Alps Otome', P. mume, P. persica for. persica, and V. corymbosum 'Reka' increased in shading. Fresh weight of leaves make inconsistent response to shading in every species but dry weight of E. umbellata var. coreana and P. persica for. persica showed the highest 150% and 148%, increment, respectively. Althought leaf water content of E. umbellata var. coreana decreased in shading, there is no difference in P. persica for. persica. Chlorophyll value of E. umbellata var. coreana and P. persica for. persica that showed higher than any other species is correlated with dark leaf green. Compared to specific leaf weight of E. umbellata var. coreana, P. persica for. persica, and V. corymbosum 'Reka' showed lower than any other species in shading, that of M. domestica 'Fujii', and R. fructicosus increased in reverse. These results indicate that E. umbellata var. coreana and P. persica for. persica that showed high value in several invesetigaton items are suitable for shady urban condition considering leaf growth in response to shading.

• 한국전문물리치료학회지
• /
• 제27권2호
• /
• pp.149-154
• /
• 2020

Background: The range of pelvic tilt is one of modifiable risk factors in preventing the lower back pain. Objects: The purpose of this study were to compare the range of pelvic tilt motion by testing position and sex. Methods: One hundred five young adults (61 females and 44 males) agreed to participate in measuring the anterior and posterior pelvic tilt with the PALM (Palpation Meter) in sitting and standing. The range of pelvic tilt motion was defined as the difference between the pelvic anterior and posterior tilt angles. Results: In general, the anterior pelvic tilt was greater (p < 0.01) in standing than in sitting and the posterior pelvic tilt was lesser (p < 0.01) in sitting than in standing. The anterior pelvic tilt in sitting and standing was greater (p < 0.01) in the females than in the males. However, the effect of sex on the posterior pelvic tilt was only significant in sitting (p < 0.01), but not in standing (p = 0.78). The range of pelvic tilt was greater (p = 0.03) in sitting but not significantly (p = 0.07) affected by the sex. Conclusion: The pelvic tilt motion in these young adults showed large variability and further studies are needed to understand better its relationship to the prevalence of the lower back disorders.

• 가정∙방문간호학회지
• /
• 제27권1호
• /
• pp.82-91
• /
• 2020

Purpose: This study aimed to explore the factors influencing attitudes toward withdrawal of life-sustaining treatment (WLST) in adolescents. Methods: This study used a descriptive research design. A structured questionnaire was administered to 185 adolescents. Data were analyzed based on t-tests, analysis of variance, Pearson's correlation coefficient, and multiple regression using the IBM SPSS 20.0. Statistical package. Results: There was a negative correlation between attitudes toward WLST and respect for life (r=-.188, p=.010). Knowing about life-sustaining treatment (β=-0.30, p<.001), experience of WLST education (β=0.21, p=.003), experience of respect for life education (β=-0.16, p=.021), and experience of death (family or acquaintance) (β=-0.13, p=.039) explained 16.7% (F=8.39, p<.001) of the variance in attitudes toward WLST. The respect for life did not affect attitudes toward WLST (β=-0.07, p=.347). Conclusion: The study findings suggest that WLST in adolescents is different from that of adults. Further research is needed to develop strategies for sound and positive attitudes toward WLST in adolescents.

• Journal of Nutrition and Health
• /
• 제27권10호
• /
• pp.1070-1077
• /
• 1994

The purpose of this study was to measure the counseling effects for diabetes mellitus patients. To measure the effects of the nutrition counseling, 40(13 men and 27 women) outpatients with diabetes mellitus were selected and they were randomly assigned to either the counseling group or non counseling group. Twenty-one counseling group patients received nutrition counseling weekly for 6 weeks and 19 patients served as non counseling group(control group) did not received counseling over same study period. The results of this study can be summerized as follows : 1) The food attitude score of the counseling group significantly increased from 61.9$\pm$15.9 prior to counseling to 87.0$\pm$7.8 after counseling (p<0.001). 2) Fasting blood glucose level and postgrandial blood glucose level also showed significant difference between two groups(p<0.01). In the counseling group, the fasting blood glucose level significantly decreased from 163.5$\pm$48.6mg/dl to 142.3$\pm$40.6mg/dl(p<0.01), and the postgrandial blood glucose level significantly decreased from 281.3$\pm$105.1mg/dl(p<0.001). 3) There was a significant difference of glycosylated hemoglobin between the two groups(p<0.005), and the glycosylated hemoglobin level of counseling group significantly decreased from 11.2$\pm$2.9% to 9.7$\pm$3.6%(p<0.005). 4) There was a significant correlation between the food attitude score difference and the glycosylated hemoglobin level difference in counseling group(p<0.05).

• 한국보건간호학회지
• /
• 제27권3호
• /
• pp.619-632
• /
• 2013

Purpose: The purpose of this study was to develop an obesity management program for obese children and examine its effects on body composition, self-efficacy, and health promotion. The obesity management program was based on a KAP & HBM mixed model and consisted of health education and group playing exercises. Method: This study was implemented at one elementary school in K city for a total of 12 weeks. The study subjects were a single group, and their body composition, self-efficacy, and health promotion were assessed at both pre-treatment and post-treatment. Data were analyzed by Wilcoxon Signed Rank Test using SPSS WIN 20.0. Result: After the program, the average height of subjects increased by 0.9cm (p=.001), whereas BMI decreased by $0.64kg/m^2$ (p=.003), obesity index decreased by 3.79% (p=.003), and body fat decreased by 1.34% (p=.002). There were significant effects on diet self-efficacy (p=.027), exercise self-efficacy (p<.001), and health promotion (p=.001). Conclusion: This obesity management program reduced the degree of obesity and improved self-efficacy and health promotion. Therefore, the obesity management program is an effective intervention method for elementary-aged obese children.

• 한국연초학회지
• /
• 제27권2호
• /
• pp.219-225
• /
• 2005

Characterizing nicotine delivery from tobacco products is important in the understanding of their addictive potential. Most previous studies report total nicotine and have not differentiated between nicotine in its protonated or free-base form. The amount of free nicotine calculated by determining pH and nicotine contents. The pH and nicotine contents in smokeless tobacco product, tobacco products and tobacco leaves were analyzed by Health Canada-Official Method T-310 and CORESTA Recommended Method $N^{\circ}62$. The content of free nicotine was calculated according to the Henderson-Hasselbalch equation and the value of $\alpha_{fb}$(the fraction of nicotine that is in the free base form) by using a pKa value of 8.02 for nicotine. The percentage of free nicotine then was calculated by dividing the free nicotine content by total nicotine content. The pH value and percentage of free nicotine ranged from 5.01 to 5.45 and $0.10\%\;to\;0.27\%$ in cut tobacco and 5.10 to 7.10 and $0.12\%\;to\;10.73\%$ in tobacco leaves, respectively.

• 한국식품영양학회지
• /
• 제27권3호
• /
• pp.522-531
• /
• 2014

The purpose of this study was to investigate the antioxidant effects of Mori cortex radicis powder and to determine the optimal composite recipe by testing different amount of Mori cortex radicis powder and sugar in cookies prepared with Mori cortex radicis powder. In regard to its antioxident effects, Mori cortex radicis powder had a total phenolic content and DPPH free radical scavenging activity of 149.56 mg GAE/g and $137.77{\mu}g/mL$, respectively. The response surface methodology was used to obtain ten experimental points (including two replicates for Mori cortex radicis powder and sugar) and Mori cortex radicis cookie formulation was optimized using rheology. The results of the sensory evaluation produced significant values for color (p<0.05), texture (p<0.05), sweetness (p<0.01) and overall quality (p<0.05), and the results of instrumental analysis showed significant values in sweetness (p<0.001), redness (p<0.01) and spread ratio (p<0.5). As a result, the optimum formulations obtained by numerical and graphical methods were found to be 16.84 g of Mori cortex radicis powder and 64.42 g of sugar.

• 한국수소및신에너지학회논문집
• /
• 제27권2호
• /
• pp.220-229
• /
• 2016

A numerical study on lifted flame structure in impinging jet geometry with syngas composition ratio was investigated. The numerical calculations including chemical kinetic analysis were conducted using SPIN application of the CHEMKIN Package with Davis-Mechanism. The flame temperature and velocity profiles were calculated at the steady state for one-dimensional stagnation flow geometry. Syngas mixture compositions were adjusted such as $H_2:CO=10:90(10P)$, 20 : 80 (20P), 30 : 70 (30P), 40 : 60 (40P), 50 : 50 (50P). As composition ratios are changed from 10P to 50P, the axial velocity and flame temperature increase because the contents of hydrogen that have faster burning velocity increase. This phenomenon is due to increase in good reactive radicals such as H, OH radical. As a result of active reactivity, the burning velocity is more faster and this is confirmed by numerical methods. Consequently, combustion reaction zone was moved to burner nozzle.

• 한국물환경학회지
• /
• 제27권4호
• /
• pp.516-522
• /
• 2011

This study was performed to investigate the removal characteristics of phosphate by adsorption on olivine, which is generated as industrial by-products from quarry. The adsorption of phosphate on olivine was significantly achieved within 1 hour and equilibrated after 3 hours. The adsorption capacity of phosphate was enhanced with decreasing pH. The maximum adsorption capacity was observed to be 0.463 mg/g in the condition of pH 3. The $Ca^{2+}$ and $Mg^{2+}$ ion amount per adsorbent eluted from olivine was increased with decreasing pH. The precipitation test showed that phosphate in aqueous phase under the condition of pH 3 ~ 9 could be eliminated largely by adsorption on olivine, not precipitation. Freundlich adsorption model were successfully applied to describe the adsorption behavior of phosphate on olivine. The $q_m$ of Langmuir adsorption model were 1.3369 mg/g, 1.0544 mg/g, 1.0288 mg/g at pH 3, 6 and 9, respectively. The $K_F$ of Freundlich adsorption model were 0.4247 mg/g, 0.3399 mg/g, 0.2942 mg/g at pH 3, 6 and 9, respectively. The olivine showed high feasibility as a adsorbent for the removal of $PO_4$-P.