• Proceedings of the Korean Magnestics Society Conference
• /
• 2012.11a
• /
• pp.90-90
• /
• 2012

• Nuclear Engineering and Technology
• /
• v.29 no.1
• /
• pp.35-44
• /
• 1997

Critical too-Phase flow rates of subcooled water through Short Pipes (L 140039n) with small diameters (D$\leq$7.15 min) have been experimentally investigated for wide ranges of subcooling (0~199$^{\circ}C$) and pressure (0.5~2.0 MPa). To examine the effects of various parameters (i.e., the location of flashing inception, the degree of subcooling, the stagnation temperature and pressure, and the pipe size) on the critical two-phase flow rates of subcooled water through short pipes with small diameters, a total of 135 runs were made for various combinations of test parameters using four different L/D test sections. Experimental results that show effect of various parameters on subcooled critical two phase flow rates are presented in the form of graphs such as the dimensionless mass flux ( $G^{*}$) versus the dimensionless subcooling ( $T_{sub}$$^{*}$) curve. An empirical correlation expressed in terms of a dimensionless subcooling is also obtained for subcooled two-phase flow rates through present test sections. Comparisons between the mass fluxes calculated by present correlation and a total of 755 selected experimental data points of 9 different investigators show that the agreement is fairly good except for very low subcooling data obtained from small L/D (less than 10) orifices.s.s.s.

• Journal of East-West Nursing Research
• /
• v.24 no.2
• /
• pp.91-100
• /
• 2018

Purpose: This study was conducted to identify the effects of a simulation practicum using standardized patients on nursing student's communication skills, critical thinking disposition and clinical competency. Methods: A one group pretest-posttest design was used. The participants consisted of 45 fourth year nursing students at G university. This study developed 2 scenarios for patients with diabetes mellitus and the simulation was conducted for an average of approximately 14 hours. Data were analyzed with descriptive analysis, t-tests and Cronbach's ${\alpha}$ using SPSS 21.0 program. Results: Communication skills, clinical competency and self-confidence for diabetic care were statistically improved; however, critical thinking disposition was not improved compared to that of pretest. Conclusion: Simulation practicum using standardized patients may be effective in enhancing communication skills, clinical competency and self-confidence for diabetic care among nursing students. In addition, standardized patients simulation program to promote the critical thinking needs to be developed and further research related to standardized patients simulation is in need.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.171-171
• /
• 2022

Effect of temperature during the period of 10 days from transplanting (10 DFT) on the growth and development of rice plants was investigated by transplanting semi-adult seedlings six times from 5 April to 15 May at 10-day interval in the field conditions of 2020 and 2021, with aims to investigate the critical temperature for early transplanting of temperate rice. In the two experimental years, mean temperature for 10 DFT appeared 9.1, 10.5, 11.6, 13.8, 13.9, 16.2, 16.4, 16.7, 17.1, 17.8℃ depending on the transplanting date. Mean temperature of 9.1℃ and 10.5℃ for 10 DFT appeared in the April 5 and April 15 transplants in 2020 showed negative or no effect on the increase of rice growth and acceleration of heading date when compared to those of right after transplanting treatments in the same year. Mean temperature of 11.6℃ for 10 DFT appeared in the April 5 transplant in 2021 demonstrated greater biomass from early to heading stage but the same heading date compared to April 15 transplant, indicating that 11.6℃ for 10 DFT had a positive effect on rice growth but no effect on advanced heading. Both more biomass and advanced heading stage were observed when the mean temperature for 10 DFT was 13.8℃ or higher, compared to those of right after transplanting treatments. These findings indicate that effective 10-DFT mean temperature for rice growth exists between 10.5 and 11.6℃, and that for rice development in terms of heading stage lies between 11.6 and 13.8℃ in natural condition. Further field and indoor studies are suggested to narrow down the critical temperature for early transplanting of temperate rice, which will enable to maximize the crop period in high altitude regions with low temperature.

• Nuclear Engineering and Technology
• /
• v.47 no.1
• /
• pp.85-93
• /
• 2015

Background: $^{241}Am$, $^{243}Am$, and $^{237}Np$ isotopes are among the most radiotoxic components of spent nuclear fuel. Recently, researchers have planned different incineration scenarios for the highly radiotoxic elements of nuclear waste in critical reactors. Computational methods are widely used to predict burnup rates of such nuclear wastes that are used under fuel matrixes in critical reactors. Methods: In this work, the Monte Carlo N-particle transport code was used to calculate the neutronic behavior of a transuranic (TRU)-bearing CANada Deuterium Uranium 6 reactor. Results: The computational data showed that the 1.0% TRU-containing thorium-based fuel matrix presents higher proliferation resistance and TRU depletion rate than the other investigated fuel Matrixes. The fuel matrix includes higher negative temperature reactivity coefficients as well. Conclusion: The investigated thorium-based fuel matrix can be successfully used to decrease the production of highly radiotoxic isotopes.

• Journal of Korean Academy of Nursing
• /
• v.41 no.6
• /
• pp.768-779
• /
• 2011

Purpose: This study was designed to adapt a surgical wound care algorithm that is used to provide evidence-based surgical wound care in a critical care unit. Methods: This study used, the 'ADAPTE process', an international clinical practice guideline development method. The -'Bonnie Sue wound care algorithm' - was used as a draft for the new algorithm. A content validity index (CVI) targeting 135 critical care nurses was conducted. A 5-point Likert scale was applied to the CVI test using a statistical criterion of .75. Results: A surgical wound care algorithm comprised 9 components: wound assessment, infection control, necrotic tissue management, wound classification by exudates and depths, dressing selection, consideration of systemic factors, wound expected outcome, reevaluate non-healing wounds, and special treatment for non-healing wounds. All of the CVI tests were ${\leq}$.75. Compared to existing wound care guidelines, the new wound care algorithm provides precise wound assessment, reliabilities of wound care, expands applicability of wound care to critically ill patients, and provides evidence and strength of recommendations. Conclusion: The new surgical wound care algorithm will contribute to the advancement of evidence-based nursing care, and its use is expected as a nursing intervention in critical care.

• Progress in Superconductivity
• /
• v.3 no.1
• /
• pp.5-12
• /
• 2001

Our experimental research focuses on manipulating pinning deflects to alter the phase diagram of vortex matter, creating new vortex phases. Vortex matter offers a unique opportunity for creating and studying these novel phase transitions through precise control of thermal, pinning and elastic energies. The vortex melting transition in untwinned YB $a_2$C $u_3$ $O_{7-}$ $\delta$/ crystals is investigated in the presence of disorder induced by particle irradiation. We focus on the low disorder regime, where a glassy state and a lattice state can be realized in the same phase diagram. We follow the evolution of the first order vortex melting transition line into a continuous transition line as disorder is increased by irradiation. The transformation is marked by an upward shift in the lower critical point on the melting line. With columnar deflects induced by heavy ion irradiation, we find a second order Bose glass transition line separating the vortex liquid from a Bose glass below the lower critical point. Furthermore, we find an upper threshold of columnar defect concentration beyond which the lower critical point and the first order melting line disappear together. With point deflect clusters induced by proton irradiation, we find evidence for a continuous thermodynamic transition below the lower critical point..

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.05a
• /
• pp.343-346
• /
• 2004

The purpose of our research is to identify the critical variables and to develop a new methodology for market segmentation of online game market. Our research tested the model with Korean online game users because Korean online game industry is the frontier of global online game industries. Conclusively, the critical variables are the suitability of feedback, the reality of design, the precision of information and the involvement of virtual community. The analysis of segmentation shows that the primary target audiences are positively influenced by the reality of design and the involvement of virtual community. To attract the primary target audiences, online game companies should develop strategies depending on the effectiveness of the variables and the demographic and behavioral characteristics of target audiences.

• International Journal of Precision Engineering and Manufacturing
• /
• v.9 no.4
• /
• pp.63-65
• /
• 2008

The increased interest in reducing the environmental effects caused by releasing organic compounds and aqueous waste has motivated the development of polymeric materials in supercritical fluids. Recently, supercritical fluids have been used in material synthesis and processing because of their special properties, such as high diffusivity, low viscosity, and low surface tension. Supercritical carbon dioxide is the most attractive because it is non-toxic, non-flammable, and has moderate critical temperature and critical pressure values. Supercritical carbon dioxide can also swell most polymers. In this study, we prepared polymer/clay nanocomposites using supercritical fluids. Cloisites 10A, 15A, 25A, and 30B used in this study are montmorillonites modified with a quaternary ammonium salt. The nanocomposites of polymer/clay were characterized by X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.5
• /
• pp.329-335
• /
• 2004

Acid deposition in forest adjacent to the industrial complexes causes soil acidification resulting in the leaching of cations, decreases of buffering capacity and increases of toxic metal concentrations such as Al, Fe, Mn and Cu in soil solution. Changes of nutrient availability equilibria by acid deposition have been known to retard the growth of pine trees. Objective of this research was to assess the critical ratios of Ca/Al and Mg/Al limiting the growth of Pinus thunbergii in the hydroponic culture. The Ca concentration and Ca/Al ratio in stalks of pine tree were increased as increasing Ca/Al molar ratio in the nutrient solution, but were not changed when the Ca/Al molar ratio was adjusted to greater than 1. Growth of Pinus thunbergii was inhibited at the Ca/Al molar ratio lower than l due to the Ca deficiency. The molar ratios of Ca/Al in the needles of Pinus thunbergii showed the similar tendency with the stalks. This indicated that Ca/Al molar ratio of 1 in the growth media was the critical level limiting the growth of Pinus thunbergii. Concentration of Mg and Mg/Al molar ratios in the stalks of pine tree were increased as increasing Mg/Al molar ratio in nutrient solution. Molar ratios of Mg/Al in the needles were increased as increasing Mg/Al ratios in nutrient solution up to 0.83, which was the critical level limiting the growth of Pinus thunbergii.