• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.86-90
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• 2008

Water reuse of effluent is limited, due to bacteria and chromaticity or turbidity which may result in low perception of water quality. Consequently, this study showed a method in the reuse of treated wastewater by a diversified treatment method, with separation of centralized reformation of aeration tank into pre-treatment with minimum installation of facilities, and post-treatment, applying advanced oxidation treatment. A pilot plant experiment was performed using Sym-Bio process adopting an NADH Sensor without modification of the exiting aeration tank. The Dissolved Ozone Flotation process, which is an advanced oxidation process, to treat the remaining organics, nutrients, chromaticity, turbidity and bacteria. As a result in the Sym-Bio process, the biological treatment, even on the condition of single stage reaction tank, the treatment efficiencies of BOD, $COD_{Mn}$, $COD_{Cr}$, SS and T-N were 96.6%, 84.6%, 88.25%, 95.1% and 71.0%, respectively, while that for T-P was 25.0%, which required further treatment. In the Dissolved Ozone Flotation process, the advanced oxidation treatment, the treatment efficiencies of BOD, $COD_{Mn}$, $COD_{Cr}$, SS, T-N, T-P, chromaticity, turbidity, bacteria, coliforms were 78.9%, 34.6%, 28.7%, 48.0%, 70.4%, 82.4%, 84.0%, 74.5%, 99.8% and 99.4%, respectively.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.15 no.4
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• pp.495-503
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• 2008

Purpose: To date most research related to patients with breast cancer has discriminately investigated the status within or after the treatment although the patients demand holistic nursing care from the time of diagnosis. Thus, the purpose of this study was to investigate the trajectory of breast cancer diagnosis and patients' experiences in the pre-treatment period. Method: This qualitative study used qualitative thematic analysis. Nineteen Korean women who were diagnosed with breast cancer within the last 6 month participated in the study. Individualized interviews were conducted with each participant in a cancer center in K city. The interviews were tape-recorded, transcribed, and analyzed using the thematic analysis process. Results: The overriding theme was "the scattered life in an unforeseen swirl", which illustrates the participants' unexpected crisis with confusion and emotional distress. Two subthemes included "falling into an unavoidable journey", and "staggering in a muddle with urgency". The categories were "unexpected probability", "nagging nodularity", "ominous presentiment", "emotional upheaval", "bad thought intrusion", and "a sense of urgency". Conclusion: Patients in the pre-treatment period encountered utter emotional distress and a sense of urgency after being diagnosed breast cancer. Strategies to develop nursing care for patients in this period and nursing implications are discussed.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1862-1864
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• 2005

Carbon nanotubes [CNTs] are grown on TiN-coated Si substrates at $700^{\circ}C$ by inductively coupled plasma-chemical vapor deposition (ICP-CVD). Pre-treatment of Ni catalysts has been performed using an RF magnetron sputtering system. Structural properties and field-emission characteristics of the CNTs grown are analyzed in terms of the RF power applied and the treatment time used in the pre-treatment process. The characterization using various techniques, such as FE-SEM, AFM, and Raman spectroscopy, show that the physical dimension as well as the crystal quality of CNTs are changed by pre-treatment of Ni catalysts. It is also seen that Ni catalysts with proper grain size and uniform surface roughness may produce much better electron emission. The physical reason for all the measured data obtained are discussed to establish the relationship between the structural property and the electron emission characteristic of CNTs.

• Journal of the Korean Society for Heat Treatment
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• v.14 no.1
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• pp.27-34
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• 2001

The effects of pre-heat treatment(Q/T) on microstructure and hardness of STD11 and STD61 tool steel nitrided by micro-pulse plasma were investigated. The quenching temperature for obtaining matrix hardness of STD11 and STD61 steel on range of HRC 50 to HRC 60 desired for machine parts is about $1070^{\circ}C$ and $1020^{\circ}C$ respectively. The hardness of STD11 and STD61 quenched at the temperature was HRC 63 and HRC 56 respectively. The nitrided case depth of STD11 and STD61 nitrided at $550^{\circ}C$ for 5 hours was independent of pre-heat treatment condition and the depth was approximately $100{\mu}m$. However, hardness and compactness of nitrided layer on Q/T treated specimen were higher than the annealed specimen. The case depth increased linearly with the increase of nitriding temperature, however, the hardness of nitrided layer decreased with the increase of temperature. Phase mixture of ${\gamma}-Fe_4N$ and ${\varepsilon}-Fe_{2-3}N$ was detected by XRD analysis in the nitrided layer formed at the optimum nitriding condition. The optimum nitriding temperature was approximately $490^{\circ}C$ which was $10^{\circ}C$ lower than the tempering temperature for preventing softening behavior of STD11 and STD61 matrix during nitriding process and the surface hardness of nitrided layer obtained by optimum pre-heat treatment condition was about Hv1400.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2448-2450
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• 2005

A robotic external fixation system for the surgery of bone deformity correction was developed to simulate the execution process of mal-unioned femur by the adjustment of the joints of the fixation system. An inverse kinematics analysis algorithm was developed to calculate the necessary rotations and translations at each joint of the robotic system. The computer graphic model was developed for validation of the analysis result and visualization of the surgical process. For given rotational and angular deformity case, the surgical execution process using the robotic system was well matched with the pre-operative planning. The final residual rotational deformities were within $1.0^{\circ}{\sim}1.6^{\circ}$ after surgical correction process. The presented robotic system with computer-aided planning can be useful for knowledge-based fracture treatment and bone deformity correction under external fixation.

• Resources Recycling
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• v.24 no.2
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• pp.55-61
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• 2015

In this study, mechanical properties of waste ground rubber tire powder were investigated to evaluate the influence of pre-treatment process for recycling. The tensile test, fracture test and morphology observation were carried out using various kinds of waste ground tire powders, which were produced by grinding and devulcanization process, respectively. As a results, it was found that the produced rubber powder through grinding process increased its tensile strength and elongation with decreasing particle size because of decreasing surface area. Devulcanized rubber powder also increased its tensile strength and elongation by de-crosslink with sulfur. It could be also suggested that devulcanization treatment after grinding process was more efficient recycling process for both increasing tensile property and fracture elongation of waste ground rubber tire powders.

• Progress in Superconductivity
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• v.4 no.2
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• pp.176-179
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• 2003

A lot of efforts have been focused on the optimization of PIT parameters for Bi-2223/Ag wire. Bi-2223 superconducting wires with 55 filaments were fabricated by stacking, drawing process. Before rolling process, round wires were pre -annealed at 760 - 820 $^{\circ}C$ and low oxygen partial pressure. We confirmed that pre-annealing step was to transform Bi-2212 orthorhombic structure from Bi-2212 tetragonal structure and to reduce the formation of second phases. However Bi-2223 phases also were formed at higher than 76$0^{\circ}C$ of pre-annealing temperature. The engineering critical current densities (Je) of Bi-22231Ag tapes were sintered at low oxygen partial pressure were higher than t hat of the wires sintered at air. We could achieve 6500 A/${cm}^2$ of Je for the tape that was initially kept at slightly higher temperature than that of normal heat treatment.

• Journal of Hydrogen and New Energy
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• v.27 no.4
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• pp.421-430
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• 2016

To prepare mesophase pitches through low energy process, pyrolysis fuel oil with $AlCl_3$ has been modified using two-step heat treatment which is heat-treated at $330^{\circ}C$ for 3~5 h after pre-treatment at $250^{\circ}C$. The result of polarized optical microscope observation, mesophase is not observed in pitches carried out only pre-heat treatment. While mesophase content is significantly increased from 9% to 100% according to increasing secondary heat treatment time from 3 h to 5 h. Synthesizing of the mesophase pitch at low temperature of $330^{\circ}C$ is attributed to decrease of viscosity of the pitches carried out first heat treatment with $AlCl_3$. The result of Fourier-transform infrared spectroscopic analysis, it is expected that aromatization of aliphatic compounds is dominant at early secondary heat treatment, on the other hand, polycondensation reaction becomes dominant as secondary heat treatment time increases. Aromaticity and stacking height of the pitches secondary heat treated for 5 hours are more increased about 25% and 107%, respectively, than that of pitches carried out only first heat treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05a
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• pp.69-72
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• 2003

Bi-2223 superconducting wires were fabricated by stacking, drawing process with different precursor powders and different heat-treatment histories. The precursor powders were 2 kinds of Pb content. And a part of the tapes were experienced pre-annealing process which caused tetragonal structure of Bi-2212 phase to orthorhombic structure of it was during drawing process. We confirmed the transformation of Bi-2212 phase from tetragonal structure to orthorhombic structure and reduction of second phases. XRD and DC magnetization analysis were performed in order to investigate the fraction of Bi-2223 phase in Bi-2223/Ag HTS tape. We could achieve best Ic of 70 A class at the Bi-2223/Ag tape using low Pb content of precursor powder and experienced pre-annealing process. DC magnetization analysis was useful to investigate the fraction of Bi-2223 phase in the Bi-2223/Ag tape.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.4
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• pp.281-289
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• 2019

Desalination plants are generally studied with higher operating costs compared to water supply facilities. This study was conducted to reduce the cost of water production and to preserve existing water resources. Therefore, the purpose of this study was to utilize the control valves to increase maximum efficiency, thereby reducing the power of the pumps and operating costs. Specific energy consumption was shown to reduce the process operating power by up to 1.7 times from 6.17 to $3.55kWh/m^3$ based on seawater reverse osmosis 60 bar. In addition, the water intake process was divided into pre, inter, and post-according to the use method of blasting, and the water treatment process was divided into pre, inter, and post blending. In order to reduce power consumption, the blending process was combined to operate the facility, which resulted in the reduction of power consumption in the order post > pre-inter> inter blending.