• Geomechanics and Engineering
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• 제28권2호
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• pp.197-207
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• 2022

The seismic holding behaviors of plate anchor embedded into submerged coarse-grained soils were investigated considering different anchor inclinations. The limit equilibrium method and the Pseudo-Dynamic Approach (PDA) were employed to calculate the inertia force of the soils within the failure rupture. In addition, assuming the permeability of coarse-grained soils was sufficiently large, the coefficient of hydrodynamic force applied on the inclined plate anchor is obtained through adopting the exact potential flow theory. Therefore, the seismic holding resistance was calculated as the combination of the inertia force and the hydrodynamic force within the failure rupture. The failure rupture can be developed due to the uplift loads, which was assumed to be an arc of a circle perpendicular to the anchor and inclines at (π/4 - φ/2). Then, the derived analytical solutions were evaluated by comparing the static breakout factor N_γ to the published experimental and analytical results. The influences of soil and wave properties on the plate anchor holding behavior are reported. Finally, the dynamic anchor holding coefficients N_γd, were reported to illustrate the anchor holding behaviors. Results show that the soil accelerations in x and z directions were both nonlinear. The amplifications of soil accelerations were more severe at lower normalized frequencies (ωH/V) compared to higher normalized frequencies. The coefficient of hydrodynamic force, C, of the plate anchor was found to be almost constant with anchor inclinations. Finally, the seismic anchor holding coefficient oscillated with the oscillation of the inertia force on the plate anchor.

• 방사성폐기물학회지
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• 제19권3호
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• pp.353-366
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• 2021

The solubilities of different multicomponent lanthanide oxide (Ln₂O₃) solid solutions including binary (Ln₁ and Ln₂ = La, Nd, Eu, or Tm), ternary (Ln₁, Ln₂, and Ln₃ = La, Nd, Eu, or Tm), and higher systems (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) were studied after aging for four weeks at 60℃. Our recent study revealed that the phase transformations in binary ((La, Nd) and (La, Eu)) and ternary (La, Nd, Eu) systems are responsible for the formation of (La, Nd)(OH)₃, (La, Eu)(OH)₃, and (La, Nd, Eu)(OH)₃ solid solutions, respectively. The variations in the mole fractions of La³⁺, Nd³⁺, and Eu³⁺ in the sample solutions of these hydroxide solid solutions indicated that a thermodynamic equilibrium might account for the apparent La, Nd, and Eu solubilities. Conversely, the binary and ternary systems containing Tm₂O₃ as the heavy lanthanide oxide retained the oxide-based solid solutions, and their solubility behaviors were dominated by their congruent dissolutions. In the higher multicomponent system, the X-ray diffraction patterns of the solid phases, before and after contact with the aqueous phase indicated the formation of a stable oxide solid solution and their solubility behavior was explained by its congruent dissolution.

• 간호행정학회지
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• 제22권5호
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• pp.480-495
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• 2016

Purpose: The purpose of the study was to identify characteristics of nursing and caring concepts measured by nursing competencies or caring behaviors tools for general nurses working in acute care hospitals. Methods: Five major nursing literature databases were used to identify the relevant tools. The study included 19 nursing competencies tools with a total of 843 measurement items and 12 caring behaviors tools with 334 items. According to the International Council of Nurses (ICN)'s Competencies Framework and 8Cs suggested by Roach (1987) and Pusari (1998), the measurement items were classified by two researchers independently first and in agreement finally. Results: Competency of 'key principles of care' including sub-areas of the ICN Framework was most commonly found: on average 49.3% of nursing competencies items and 91.9% of caring behaviors items. 97.0% of the caring behaviors items were classified into one of six Cs: competence (27.5%), confidence (21.3%), compassion (17.1%), commitment (16.5%), communication (9.9%), or conscience (4.8%). Conclusion: Nursing competencies tools were more likely to measure 'what to do' focusing on tasks, while caring behaviors tools were to measure 'how to do' focusing on nurses' attitudes or values. Nursing practices should be evaluated with both nursing competencies and caring behaviors tools, considering that nursing and caring were differently conceptualized in the quantitative tools.

• 한국생활과학회지
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• 제18권2호
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• pp.313-324
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• 2009

The study is to investigate mothers' parental beliefs about child development and the children's developmental tasks, and to explore the relationship between mother's parental beliefs and child-rearing behaviors. The subjects are 113 pairs of 4- to 5-year-old children and their mothers. For measuring maternal beliefs about child-development, 'beliefs about development scale' and 'child-rearing beliefs scales' were used. For mother's child-rearing behaviors, 'child rearing behavior observation scale' was used. The main results were: first, mothers value the cognitive theory and 'autonomous behavior' higher than 'conforming behavior' in developing their children. Second, there were no differences in mother's parenting beliefs in the factors of 'gender of their children' and 'maternal job status', while there were significant differences in maternal beliefs according to the levels of mother's education and family income. Third, sub-scales of their parenting beliefs were correlated with interactive behaviors between them and their children. The more mothers put importance on cognitive theory and children's autonomous behaviors, the more their supportive child-rearing behaviors during child-mother task solving situations were showed.

• 대한가정학회지
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• 제43권11호
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• pp.211-224
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• 2005

The purposes of this study were firstly to reveal the sub-dimensions of time management behaviors and secondly to group workers by time management behaviors. The major findings of this study were as follows. (1)Factor analysis of the 36 items on the time management behaviors instrument revealed three components: factor planning, relations-intention, and urgency. (2)Workers were categorized into four types by the level of those three factors of time management behaviors: 'accomplishment type'($28.31\%$), 'chronic-urgency type'($24.39\%$), 'valuing-job type'($23.73\%$) and 'valuing-human relations type'($23.57\%$). (3)The accomplishment type gained the highest points on the time management satisfaction score, and the level of important${\cdot}$non-urgencies was the highest score, indicating that the accomplishment type had good time management. However, the level of unimportant${\cdot}$urgencies was the highest score. Therefore, this type should try to reduce the level of unimportant${\cdot}$urgencies.

• 한국분말재료학회지
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• 제29권5호
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• pp.357-362
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• 2022

The low-temperature sinterability of TiO₂-CuO systems was investigated using a solid solution of SnO₂. Sample powders were prepared through conventional ball milling of mixed raw powders. With the SnO₂ content, the compositions of the samples were Ti_1-xSn_xO₂-CuO(2 wt.%) in the range of x ≤ 0.08. Compared with the samples without SnO₂ addition, the densification was enhanced when the samples were sintered at 900℃. The dominant mass transport mechanism seemed to be grain-boundary diffusion during heat treatment at 900℃, where active grain-boundary diffusion was responsible for the improved densification. The rapid grain growth featured by activated sintering was also obstructed with the addition of SnO₂. This suggested that both CuO as an activator and SnO₂ dopant synergistically reduced the sintering temperature of TiO₂.

• 한국분말재료학회지
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• 제31권2호
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• pp.146-151
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• 2024

Pure SnO₂ has proven very difficult to densify. This poor densification can be useful for the fabrication of SnO₂ with a porous microstructure, which is used in electronic devices such as gas sensors. Most electronic devices based on SnO₂ have a porous microstructure, with a porosity of > 40%. In pure SnO₂, a high sintering temperature of approximately 1300℃ is required to obtain > 40% porosity. In an attempt to reduce the required sintering temperature, the present study investigated the low-temperature sinterability of a current system. With the addition of TiO₂, the compositions of the samples were Sn_1-xTi_xO₂-CoO(0.3wt%)-CuO(2wt%) in the range of x ≤ 0.04. Compared to the samples without added TiO₂, densification was shown to be improved when the samples were sintered at 950℃. The dominant mass transport mechanism appears to be grain-boundary diffusion during heat treatment at 950℃.

• 한국분말재료학회지
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• 제10권5호
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• pp.337-343
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• 2003

Nanostructured Cu-$Al_2O_3$ composite powders were synthesized by thermochemical process. The synthesis procedures are 1) preparation of precursor powder by spray drying of solution made from water-soluble copper and aluminum nitrates, 2) air heat treatments to evaporate volatile components in the precursor powder and synthesis of nano-structured CuO + $Al_2O_3$, and 3) CuO reduction by hydrogen into pure Cu. The suggested procedures stimulated the formation of the gamma-$Al_2O_3$, and different alumina formation behaviors appeared with various heat treating temperatures. The mean particle size of the final Cu/$Al_2O_3$ composite powders produced was 20 nm, and the electrical conductivity and hardness in the hot-extruded bulk were competitive with Cu/$Al_2O_3$ composite by the conventional internal oxidation process.

• 마이크로전자및패키징학회지
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• 제31권2호
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• pp.1-8
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• 2024

Bonding wires are composed of conductive metals of Au, Ag & Cu with excellent electrical conductivities for transmitting power and signals to wafer chips. Wire metals do not provide electrical insulation, adhesion promoter and corrosion passivation. Adhesion between metal wires is extremely weak, which is responsible for wire cut failures during thermal cycling. Organic coating for electrical insulation does not satisfy bondability and manufacturability, and it is complex to apply very thin organic coating on metal wires. Automotive packages require enhanced reliability of packages under harsh conditions. LED and power packages are susceptible to wire cut failures. Contrary to conventional OCB behaviors, forming gas was not required for free air ball formation for both Ag and Pd-coated Cu wires with Al₂O₃ passivation.

• 센서학회지
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• 제30권6호
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• pp.408-414
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• 2021

This study analyzes the phase transition behavior and electrical properties of lead-free (1-x)K_0.5Na_0.5NbO₃-xBaZrO₃ (KNN-100xBZ) piezoelectric ceramics. The stabilized crystal structures in BaZrO₃-modified KNN ceramics is clarified to be pseudocubic. The polymorphic phase transition from the orthorhombic to pseudocubic phases can be observed with KNN-6BZ ceramics considering the optimized piezoelectric constant (d₃₃). Electromechanical strain behaviors are discussed. Accordingly, the enhancement of strain value at x = 0.08 (composition) may originate from the coexistence of ferroelectric domains and polar nanoregions. A schematic of domains for KNN, KNN-8BZ, and KNN-15BZ ceramics has been proposed to describe the relationship between the stabilized relaxor and changes in electrical properties.