• Journal of Korean Biological Nursing Science
• /
• v.14 no.1
• /
• pp.33-40
• /
• 2012

Purpose: The purpose of this study was to explore the relationship between cyber leisure activity and autonomic function in high school students. Methods: The subjects of this study were 242 second graders at high school located in D city. The research design was descriptive correlation study. Data were collected from August 26 to September 17, 2010, using a cyber leisure questionnaire and heart rate variability (SA-6000, Medicore, Korea) for autonomic function. Results: Total time for the cyber leisure activity was $391.3{\pm}262.0$ (min/week). Time for internet usage and computer game was $234.5{\pm}140.1$ (min/week) and $156.8{\pm}164.3$ (min/week), respectively. There were significant positive correlation between total cyber leisure time and sympathetic activity (r=.247, $p$ <.001). Conclusion: Excessive cyber leisure activity could increase sympathetic activities in high school students. Thus, nursing intervention to reduce the total cyber leisure time will be helpful to improve their neurophysiological status.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.05c
• /
• pp.118-122
• /
• 2001

The ${\beta}-SiC+TiB_2$ ceramic electroconductive composites were pressureless-sintered and annealed by adding 12wt% $Al_2O_3+Y_2O_3$(6 : 4wt%) powder as a function of sintering temperature. The relative density is over 78.83% of the theoretical density and increased with increasing sintering temperature. The phase analysis of the composites by XRD revealed of $\alpha$-SiC(6H), $TiB_2$, $Al_5Y_2O_{12}$ and $\beta$-SiC(15R). Flexural strength showed the highest of 140 MPa for composites sintered at $1900^{\circ}C$. The vicker's hardness increased with increasing sintering temperature and showed the highest of 4.07 GPa at $1900^{\circ}C$. Owing to YAG, the fracture toughness showed the highest of 4.07 $MPa{\cdot}m^{1/2}$ for composites at $1900^{\circ}C$. The electrical resistivity was measured by the Pauw method from $25^{\circ}C$ to $700^{\circ}C$. The electrical resistivity of the composites showed the PTCR(Positive Temperature Coefficient Resistivity).

• Bulletin of the Korean Chemical Society
• /
• v.30 no.7
• /
• pp.1516-1520
• /
• 2009

A sensitive technique for the determination of trace Co(II) in various samples after column preconcentration by adsorbing onto silica gel loaded with 1-nitroso-2-naphthol was developed. Several experimental conditions, such as pH of sample solution, the amount of silica gel loaded with 1-nitroso-2-naphthol, the flow rate for adsorption and so forth, were optimized. The interfering effects of diverse concomitant ions were investigated. Fe(III) interfered with more than any other ions, but the interference by Fe(III) was completely eliminated by adjusting the amount of silica gel loaded with 1-nitroso-2-naphthol to 0.30 g. The dynamic range, the correlation coefficient ($R^2$), and the detection limit obtained by the proposed technique were 3.0-140.0 ng m$L^{-1}$, 0.9942, and 1.81 ng m$L^{-1}$, respectively. For validating the technique, the aqueous samples (tap water, reservoir water, stream water, and wastewater) and the plastic samples were used as real samples. Recovery yields of 93.0-107.0% were obtained. These measured data were not different from ICP-MS data at the 95% confidence level by F test. Based on the results of the experiment, it has been found that the proposed technique can be applied to the determination of Co(II) in various real samples.

• Research in Community and Public Health Nursing
• /
• v.10 no.1
• /
• pp.140-153
• /
• 1999

This study is designed to furnish basic data for development of health -care program to promote health of the middle-aged adult by making the middle-aged adult an object who have radically increasing death rate because of chronic degenerative diaease, finding out the executive degree of health -promoting behaviors, and verifying the relation between self-efficacy/perceived health status and health -promoting behaviors. The results are as follows. 1) The hypothesis that 'the higher the self-efficacy, the better the health -promoting behaviors' was supported on a meaningful level(r=.30l, p=.000) 2) The hypothesis that 'The health-promoting behaviors will have differences according to the perceived health status' was supported on a meaningful level in the sections of the control of stress(p=.000), the self-achievement (p=.000), the exercise(p=.002), the control of interpersonal relation(p=.014) and the eating habit(p=.061) and was rejected in the sections of drinking' smoking(p=.787), heath-responsibility (p=.061). The fact that executive degree of health -promoting life-style have correlation with self-efficacy was found out and we need to develop health-education program to promote self-efficacy.

• Animal Systematics, Evolution and Diversity
• /
• v.27 no.1
• /
• pp.25-33
• /
• 2011

Three morphospecies of the genus Uronychia, i.e. U. setigera Calkins, 1902, U. binucleata Young, 1922, and U. multicirrus Song, 1997, were collected from the coastal waters of Gumjin-ri on the East Sea and the public waterfront of Incheon on the Yellow Sea in Korea, respectively. These species are described based on live observation, protargol impregnation, silver nitrate impregnation, and their morphometrics. Diagnostic keys for these species are also provided. In addition, their small subunit ribosomal DNA sequences were compared with previously known sequences of Uronychia species. Diagnostics of three Uronychia species are as follows: U. setigera: $50-80\;{\mu}m$ long in vivo, oval-shaped, 2 macronuclear nodules (Ma), 1 spur on the left margin, 11 adoral membranelles (AM) 1, 4 AM2, 1 buccal cirrus (BC), 4 frontal cirri (FC), 3 left marginal cirri (LMC), 2 ventral cirri (VC), 5 transverse cirri (TC), 3 caudal cirri (CC), 6 dorsal kineties (DK), and approximately 23 cilia in the leftmost kinety. U. binucleata: $70-110\;{\mu}m$ long in vivo, oval to slightly rectangular shaped, 2 Ma, 1 micronucleus (Mi), 2 spurs on the posterior region, 11 AM1, 4 AM2, 1 BC, 4 FC, 3 LMC, 2 VC, 5 TC, 3 CC, 6 DK, and approximately 37 cilia in the leftmost kinety. U. multicirrus: $140-200\;{\mu}m$ long in vivo, oval to slightly rectangular shaped, ca. 7 Ma, 1 Mi, 11 AM1, 4 AM2, 1 BC, 4 FC, 3 LMC, approximately 8 VC, 5 TC, 3 CC, and 6 DK. This study presents the first record of this genus in Korea.

• Women's Health Nursing
• /
• v.7 no.4
• /
• pp.622-630
• /
• 2001

This study aims at examining relationships between body mass index and perceived body shape and image. Using a purposive sampling method, 404 female college students were recruited from three universities located in Busan from April 2000 to June 2000. To classify the levels of obesity, Broca's method was used. Secord & Jourard's Body Cathexis Scale(1953) modified by Kim mi ok(1997) was also used to measure body image. The collected data were analyzed with the percentages, Mean, Standard deviation, T-test, and Pearson correlation Coefficient. The results of this study were as follows. 1. 56.4 % of subjects were under weight, and 42.1% were normal for BMI. 2. 55.9% of subjects were very satisfied with their body shape and 15.1% were satisfied. 3. The mean values of perceived body shape according to the BMI were 3.0 for the overweight group, 2.65 for the normal weight group, and 2.21 for the low weight group, the mean differences among three groups were significantly satisfied (F= 21.42, P= .000). 4. The mean scores of body image according to the BMI was 160.21 for low weight group, 155.57 for the normal weight group, and 140.0 for overweight group. The mean differences among the three groups were not significantly satisfied. 5. The mean scores of body image according to perceived body shape were 17819 for the satisfaction group, 161.08 for the moderate group and 150.82 for dissatisfied group. The mean differences among the three groups were significantly satisfied (F= 35.72, P=. 000). 6. There were high positive correlations between BMI and perceived body shape(r= .317) and between perceived body shape and body image (r=- .415).

• The Journal of Korean Society for School & Community Health Education
• /
• v.1 no.1
• /
• pp.1-9
• /
• 2000

The purpose of this study were to assess the effect on health promotion behavior of health instruction in elementary school and to provide a basis of school health education. Subjects of this study were random sampled 80 students for control group in elementary 6th grade students. the treatment group systematically studied five sphere instruction: individual hygiene, disease prevention, first-aid & safety, oral health, health & nutrition in two hours a week, from April 20, till July 10. Each group was pre-tested and post-tested by health behavior promotion questionnaire. The conclusions as follows; 1. Compare analysis of control group and treatment group in the pre-test according to health condition of children were no significant difference physical health condition, health anxiety, disease-absent(P>.05). 2. Health promotion behaviors in the post-test according to concern quotient significantly correlated with individual hygiene(r=.249, P<.05), disease prevention(r=.477, P<.01), oral health(r=.228, P<.05), health & nutrition(r=.323, P<.01) in the treatment group, on the contrary the disease prevention, first-aid & safety, oral health, health & nutrition(P>.05). 3. The difference of health promotion behavior within & between group were as follow; 1) The difference of individual health hygiene with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(treatment group: $3.965{\pm}.568$, control group: $3.645{\pm}.573$). 2) The difference of disease prevention with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(t group : $3.475{\pm}.619$, c group: $3.964{\pm}.600$). 3) The difference of first-aid & safety with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(t group : $3.700{\pm}.466$, c group: $4.140{\pm}.545$). 4) The difference of oral health with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(t group: $3.163{\pm}.665$, c group: $3.753{\pm}.544$). 5) The difference of health & nutrition with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(t group : $3.255{\pm}.515$, c group: $3.698{\pm}.558$).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.3
• /
• pp.359-363
• /
• 2009

This study was performed to establish a rapid and simple analytical method for niacin (nicotinic acid and nicotinamide) using HPLC. A pretreatment method for the extraction and clean-up of niacin in infant formula sample and an instrumental condition for HPLC were optimized. Niacin was extracted by 5 mM hexanesulfonate with ultrasonication for 30 min. For the clean-up of the sample, the extract was applied to a HLB cartridge, and then niacin was eluted from the cartridge using 5 mL of 80% methanol after washing with 5 mL of n-hexane. The total recoveries were $83{\sim}104%$ and relative standard deviation were in the range of $1.5{\sim}3.5%$ during the extraction and clean-up process. Niacin was determined by gradient elution with sodium hexanesulfonate/methanol buffer as a mobile phase and a photodiode array detector (260 nm). It showed a high linearity between the content of niacin and the peak area ($r^2$=1.000) in the range of $0.02{\sim}10.0$ mg/L of nicotinic acid and nicotinamide. The detection limit was 0.02 mg/L (0.2 mg/kg in the sample). The method was successfully applied for the determination of niacin in infant formula. Total niacin contents were in the range of $53.5{\sim}140.3$ mg/kg.

• Elastomers and Composites
• /
• v.42 no.1
• /
• pp.20-31
• /
• 2007

Material characteristics and lifetime evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, the NBR compound was prepared by sulfur-cure system, and was used in predicting the lifetime of rubber gasket made by the compound. The accelerated material aging was investigated at different temperatures at 120, 140 and $160^{\circ}C$ and aging time from 3 hours to 600 hours at 5, 6, 7 vol %. of $H_2SO_4$ concentrations The rubber strips were placed in acid solution using pyrex g1ass tube. Both ends of pyrex g1ass tube were sealed to avoid evaporation of solution during heating at given time. The material test and accelerated acid-heat aging test were carried out to predict the useful life of NBR rubber gasket for a fuel cell stack. In order to investigate the effects of acid-heat aging on the properties of the NBR, tensile strength, elongation at break, hardness and crosslink-density were measured. The tensile strength decreases as the $H_2SO_4$ concentrations and temperature increase. Results were evaluated using Arrhenius equation.

• Food Science and Preservation
• /
• v.22 no.5
• /
• pp.683-689
• /
• 2015

Response surface methodology (RSM) is a statistical procedure frequently used for optimization studies. The purpose of this study was to determine the optimal spray drying condition for manufacturing Sikhye powder using RSM. Independent variables included the additive contents of maltodextrin (MD), inlet temperature, and velocity of sample feed velocity. The dependent variables were water uptake (g), solubility (%) and particle size (${\mu}m$). Regression models describing the changes of water uptake (g), solubility (%) and particle size (${\mu}m$) with respect to the independent variables were statistically significant with coefficients of determination, $R^2$, greater than 0.9. The results indicated that the inlet temperature of the spray dryer was the most important independent variable that affected the water uptake (g), while the additive content of MD and the sample feed velocity had maximum effects on the solubility (%) and particle size (${\mu}m$) of the Sikhye powder, respectively. The optimum final product was expected to have the lowest possible water uptake (g) and particle size (${\mu}m$) but the highest possible solubility (%). In conclusion, the best spray drying conditions were as follows: additive MD content, 22%; inlet temperature, $140^{\circ}C$ ; and spray dryer sample feed velocity, 51 mL/min.