• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3312-3316
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• 2013

Single crystals of hexagonal graphenes were successfully grown on Cu foils using the atmospheric pressure chemical vapor deposition (CVD) method. We investigated the effects of reaction parameters, such as the growth temperature and annealing time, on the size, coverage, and density of graphene domains grown over Cu foil. The mean size of the graphene domains increased significantly with increases in both the growth temperature and annealing time, and similar phenomena were observed in graphene domains grown by low pressure CVD over Cu foil. From the comparison of micro Raman spectroscopy in the graphene films grown with different annealing times, we found that the nucleation and growth of the domains were strongly dependent on the annealing time and growth temperature. Therefore, we confirmed that when reaction time was same, the number of layers and the degree of defects in the synthesized graphene films both decreased as the annealing time increased.

• Child Health Nursing Research
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• v.2 no.2
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• pp.5-18
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• 1996

The purposes of this study were to measure the degree of perceived uncertainty and to identify the rearing attitudes of mothers with chronically ill children, and to examine the relationship between the perceived uncertainty and the rearing attitude of these mothers. The subjects of this study consisted of 133 mothers with chronically ill children, registered at 2 university hospitals in Seoul. Data was collected from April 1 to May 31, 1996. The Parents' Perception of Uncertainty Scale(28-item 4 point scale) and the Maternal Behavior Research Instrument (49-item 5 point scale) were used. Data was analyzed by Cluster analysis, ANOVA MANOVA and t-test. Results of this study are summarized as follows : 1. Mothers perceived their uncertainty to be slightly high (Mn 2.48). The degree of perceived uncertainty by the four components slightly differed unpredictability(2.72), lack in clarity(2.58), vagueness (2.52) and lack of information(2.04) . The degree of perceived uncertainty of mothers with ill children revealed to be influenced significantly by the age of the ill children, duration of illness after the diagnosis, and the experience of hospitalization. 2. Among the rearing attitudes : moderatlely high affective(Mn 3.98) and resrictive(Mn 3.58) attitudes of mothers toward their ill children were identified. Mothers tend to give positive evaluations of their childrens' behaviors (Mn 3.38) and less rejection(Mn 2.81). 3. Mothers' rearing attitude were correlated with the degree of perceived uncertainty in illness ; mothers in the Low Perceived Uncertainty Group (Mn 1.99) revealed the highest affective (Mn 4.08), the lowest resrictive(Mn. 2.72) attitudes and tendency to give positive evaluations of their childrens' behaviors (Mn 3.54) compared to the High Perceived Uncertainty Group(Mn 3.26) and Moderate Perceived Uncertaity Group(Mn 2.57). 4. The degree of perceived uncertainty, the duration of illness after the diagnosis and the experience of hospitalization revealed to be significantly influential to the rearing attitude of mothers with chronically ill children. From the above results, it can be concluded that predicting and controlling mothers' uncertainty are necessary for improved, efficient nursing interventions and normal growth & development of the chronically ill children.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.3
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• pp.388-397
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• 1999

Numerical simulations are carried out for the magnetic Czochralski single crystal growth system. It Is shown that a magnetic field significantly suppresses the convective flow and as the strength of magnetic field becomes to be stronger, the heat transfer in the melt is dominated by conduction rather than convection. By imposing a cusp magnetic field, the growth interface shape becomes convex toward the melt. When the axial magnetic field is imposed, there occurs an inversion of the interface shape with increase of the magnetic field strength. The oxygen concentration near the interface decreases with increasing cusp magnetic field strength while axial field causes an increase of an oxygen concentration at the central region and decrease of that at the edge of the crystal. The results show that the cusp magnetic field has advantages over an axial magnetic field In the radial uniformity of oxygen as well as in the additional degree of control.

• The korean journal of orthodontics
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• v.10 no.1
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• pp.81-93
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• 1980

The interrelationships between growth rates (and size) of the selected cranifacial dimensions and body dimensions (height and weight) were investigated in the longitudinal data of primary school children from 6 to 11 years of age. The data were obtained from serial cephalometric radiographs and health record which were taken at one year interval. Regression analyses were used to analyze the data. The main concludions might be summarized as follows; 1. Size relationships between body height (and weigh) and S-Gn, posterior facial height (s-Go), total mandibular length (Ar-Gn) showed high significant correlation, but no association between body height, weight and anterior cranial base length (S-N). 2. Correlation coefficients between facial dimensions and body height (and weight) were getting lower with age increase. 3. At all age groups, significant prediction equation for some facial dimensions with body height and weight were obtained. 4. In this sample, the growth rates of facial dimensions and body height and weight showed almostly constant during this age period and the growth rate of body height and weight of girls was exceeded that of boys. 5. A relatively high degree of variation between individuals existed in the sample. 6. A positive correlation was found for the relationship between the growth rates of facial dimensions and those of body height (and weight) in boys and girls, but was not found in total samples.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.3
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• pp.286-288
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• 1999

When concentration of vacancies in a CZ silicon crystal is defined by molar fraction $X_{B}$, the degree for supersaturation $\sigma$ is given by $[X_{B}-X_{BS}]/X_{BS}=X_{B}/X_{BS}-1=ln(X_{B}/X_{BS})$ because $X_{B}/X_{BS}$ is nearly equal to unity. Here, $X_{BS}$ is the saturated concentration of vacancies in a silicon crystal and $X_{B}$ is a little larger than $X_{BS}$. According to Bragg-Williams approximation, the chemical potential of the vacancies in the crystal is given by ${\mu}_{B}={\mu}^{0}+RT$ ln $X_{B}+RT$ ln ${\gamma}$, where R is the gas constant, T is temperature, ${\mu}^{0}$ is an ideal chemical potential of the vacancies and ${\gamma}$ is and adjustable parameter similar to the activity of solute in a solute in a solution. Thus, ${\sigma}(T)$ is equal to $({\mu}_{B}-{\mu}_{BS})/RT$. Driving force of nucleation for the vacancy agglomeration will be proportional to the chemical potentialdifference $({\mu}_{B}-{\mu}_{BS})/RT$ or ${\sigma}(T)$, while growth of the vacancy agglomeration is proportaional to diffusion of the vacancies and grad ${\mu}_{B}$.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.285-290
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• 1989

The biololgical effect of the preemergence rice field herbicide, butachlor(commercial name, Machete) on purple nonsulfur photosynthetic bacterium Rhodospirillum rubrum KS-301 has been studied under cultural conditions. Bacterial growth showed a tendency to decline according to the degree of the concentration of butachlor until $10^{-3}$ M and slmost stopped at $10^{-2}$M. The growth inhibitory action at $10^{-3}$M of butachlor was evident (4.2-18.7% inhibition of growth rate) but had little effect in nitrogen fixation. Conversely, there was a little enhancement effect(1%) in pyruvate, dinitrogen gas growing cultures. At concentration of $10^{-3}$ M, instead of spiral form, rod shapes were observed through phase contrast microscope and instead of vesicular intracytoplasmic membrane, irregular tubular forms were observed through electron microscope. Alkaline pH value slightly reversed tha inhibitory action of butachlor.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.4
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• pp.135-140
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• 2005

Thermal-fluid analysis was performed to understand the thermal behavior in the horizontal CVD reactor thereby to design a susceptor which has a uniform deposition rate during silicon EPI growing. Four different types of susceptor designs, standard (no hole susceptor), hole $\sharp$1 (240 mm), hole $\sharp$2 (150 mm) and hole $\sharp$3 (60 mm), were simulated by CFD (Computational Fluid Dynamics) tool. Temperature, gas flow, deposition rate and growth rate were calculated and analyzed. The degree of flatness of EPI wafer loaded on the susceptor was computed in terms of silicon growth rate. The simulation results show that the temperature and thermal distribution in the wafer are greatly dependent on inner diameter of hole susceptor and demonstrate that the introduction of hole in the susceptor can degrade wafer flatness. Maximum temperature difference appeared around holes. As the diameter of the hole decreases, flatness of the wafer becomes poor. Among the threes types of susceptors with the hole, optimal design which resulted a good uniform flatness ($5\%$) was obtained when using hole $\sharp$1.

• Nuclear Engineering and Technology
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• v.47 no.7
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• pp.895-906
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• 2015

Background: Mitigation of primary water stress corrosion cracking (PWSCC) is a significant issue in the nuclear industry. Advanced nickel-based alloys with lower susceptibility have been adopted, although they do not seem to be entirely immune from PWSCC during normal operation. With regard to structural integrity assessments of the relevant components, an accurate evaluation of crack growth rate (CGR) is important. Methods: For the present study, the extended finite element method was adopted from among diverse meshless methods because of its advantages in arbitrary crack analysis. A user-subroutine based on the strain rate damage model was developed and incorporated into the crack growth evaluation. Results: The proposed method was verified by using the well-known Alloy 600 material with a reference CGR curve. The analyzed CGR curve of the alternative Alloy 690 material was then newly estimated by applying the proven method over a practical range of stress intensity factors. Conclusion: Reliable CGR curves were obtained without complex environmental facilities or a high degree of experimental effort. The proposed method may be used to assess the PWSCC resistance of nuclear components subjected to high residual stresses such as those resulting from dissimilar metal welding parts.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.255-262
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• 1998

This study investigated the crystallization behaviour of sealing amorphous material heat-treated by conventional and microwave heating source. From X-ray diffraction and SEM analyses, it was shown that microwave heat-treated sample had well-grown $PbTiO_3$crystals and the high degree of crystallinity inspite of its heat-treated condition of shorten time and lower temperature as compared with a conventionally heat-treated sample. It was assumed that microwaves inhibit the nucleation of $PbTiO_3$crystal in nucleation stage, but promote the growth of $PbTiO_3$crystal above the critical size of crystal due to enhanced diffusion effect within the sample.

• FLOWER RESEARCH JOURNAL
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• v.17 no.2
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• pp.75-80
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• 2009

The objective of this research was to select the native shade tolerance plant which grows well from landscape objective of the urban. Seven species native ground cover plants were evaluated on the growth and chloropyll under 0, 40, 60, 90% shading treatments. Hosta longipes was showed the quite good growth from 60% level of natural light. The plant growth of Liriope platyphylla was good within $144.2{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ intensity which is 90% shade level of natural light. But, Dryiopteris crassirhizoma was judged with shade tolerance plant which grow quite well from shading condition level of 60% degree. Carex siderosticea was showed the highest plant length and plant width in 40% shading of natural light more than at conditon too much shading. Hosta longipes, Liriope platyphylla, Dryiopteris crassirhizoma, and Carex siderosticea were as shade tolerance plant with increases chlorophyll content well to overcome a light restrictive condition and is adapted to seem with the result.