• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.1199-1204
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• 2006

The pressure drop and heat transfer coefficient were measured at room temperature in CFB heat exchanger with multiple vertical tubes. Also the circulation rate of solid particles was measured. The theoretical model for predicting heat transfer coefficient using the solid flowrate was developed in this study. The model predictions were compared with the measured heat transfer coefficient to show relatively good agreement.

• Geomechanics and Engineering
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• v.31 no.2
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• pp.159-166
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• 2022

The model of two-dimensional plane waves is analyzed in a micropolar-thermoelastic solid with microtemperatures in the context of the three-phase-lag model, dual-phase-lag model, and the Green-Naghdi theory of type III. Harmonic wave analysis is used to hold the solution to the problem. Numerical results of the physical fields are visualized to show the effects of the gravity field, magnetic field, and viscosity. The expression for the field variables is obtained generally and represented graphically for a particular medium.

• Journal of the Korean Applied Science and Technology
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• v.22 no.2
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• pp.116-122
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• 2005

Room temperature cure type of acryl-urethane coatings with high solid content were prepared in this study. Acrylic resins with 80% solid content were cured with hexamethylene diisocyanate (Desmodure N-3600). The cure time of prepared coatings BEHCC-84 (BEHC-84 : $T_g=0^{\circ}C$) and BEHCC-87 (BEHC-87 : $T_g=30^{\circ}C$), measured by rigid-body pendulum method, was recorded 8.3 hours and 3.8 hours, respectively. Dynamic viscoelastic experiment also revealed the glass transition temperature of BEHCC-84 and BEHCC-87 to be $T_g=40.3^{\circ}C$ and $T_g=43.3^{\circ}C$, respectively. It was found that the adhesion and flexural properties among various propeties of coatings were enhanced by the incorporation of caprolactone acrylate monomer into the acrylic resins.

• Journal of Distribution Science
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• v.18 no.9
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• pp.67-75
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• 2020

Purpose: The purpose of this study is to enhance sales promotion efficiency for using solid refuse fuel facilities. Renewable energy technology using Solid Refuse Fuel (SRF) is an economic efficiency technology that recovers waste by burning various wastes. A survey on the pollutants discharged from the solid fuels facilities was investigated so that the SRF facilities could be expanded, distributed and reflected in the policy. Research design, data, and methodology: In this study, 9 business sites using SRF and Bio-SRF as main raw materials were investigated for 2 years. The characteristics of target business sites such as the type of fuel used, combustion method, combustion temperature, daily fuel consumption and environmental prevention facilities were studied. Results: The average pollution & ammonia concentration of Bio-SRF facilities was found to be 88.15% higher than that of SRF facilities. But the average acetaldehyde concentration of SRF facilities was found to be 88.15% higher than that of Bio-SRF facilities. Conclusions: The main issue is how much electric power generation using combustible materials affects air pollution. The waste recycling law provides the standard value according to the fuel property, but there is a considerable gap with the mixed fuel. Therefore, for efficient utilization of facilities using solid fuel products, additional research is needed to improve the distribution structure of exhaust pollutants is needed.

• The Korean Journal of Ceramics
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• v.6 no.1
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• pp.47-52
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• 2000

Lanthanides such as La, Gd and Ce have recognized as elements of high level radioactive wastes immobilized by forming solid solution with $CaTiO_3$. For easy forming solid solution between $CaTiO_3$and lanthanides, the combustion synthesis process was applied and the powder characteristics and sinterability were investigated. The proper selection of the type and the composition of fuels are important to get the crystalline solid solution of $CaTiO_3$and lanthanides. When glycine or the mixtures of urea and citric acid with stoichiometric composition was used as a fuel, the solid solution of $CaTiO_3$with $La_2O_3$or $Gd_2O_3$or $CeO_2$was produced very well by the combustion process. The combustion synthesized powder seemed to have a good sinterability with the linear shrinkage of more than 25% up to $1500^{\circ}C$, while that of the solid state reacted powder was less than 10% at the same condition.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.133-137
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• 2010

A dual pulse solid rocket motor has several advantages compared to the single one. The range and the terminal velocity of the guided missile can be remarkably increased by the application of the pulse separation device(PSD) to the solid rocket motor which resulted in appropriate thrust distribution. In this study, the subscale dual pulse solid rocket motor with the bulkhead type PSD was designed, manufactured, and fire-tested. The bursting pressure, thermal characteristics, and the structural safety of the PSD were obtained by the tests and the results will be applied to the design of full-scale dual pulse rocket motor.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.2
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• pp.217-228
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• 2006

Statement of problem: Standard type of ITI solid implant model in the 6.2mm thick jaw bone was axisymmetrically modelled for finite element stress analyses. Purpose: Primary objective was to investigate the influences or the characteristic design configuration of the ITI solid implant model on the bone stress with the course of osseointegration process at the bone/implant interfaces. To simulate the characteristics of the osseointegration process, five different stages of the bone/implant interface model were implemented. As load conditions, vertical load of 50N was taken into consideration. Bone at the cervical region of implant was the areas of concern where the higher level of stress were likely to take place. Results: The results indicated that rather slightly different stress level could be obtained as a function of the osseointegration conditions. Conclusion: Under vertical load, the lower level of stress was observed at the cervical cortical bone in the initial and final stages of osseointegration. Relatively higher stress level, however, was observed during the transitional stages where the osseointegration at the cancellous bone interface were yet to fully develop.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.2
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• pp.170-177
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• 2019

Continuous solid circulation test at high temperature and high pressure conditions and batch type reduction-oxidation tests were performed to check feasibility of a 0.5 MWth chemical looping combustion system. Pressure drop profiles were maintained stable during continuous solid circulation up to 16 hours. Therefore, we could conclude that the solid circulation between an air reactor and a fuel reactor could be smooth and stable. The measured fuel conversion and $CO_2$ selectivity were high enough even at high capacity and even after cyclic tests. Therefore, we could expect high reactivity of oxygen carrier at real operation condition.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.884-894
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• 2011

Effects of temperature, volatile content, particle diameter and solid input weight were investigated in the batch fluidized bed reactor using OCN703-1100 particle as oxygen carrier and Roto coal and char as fuels. Two solid fuels represented the best reactivity at different temperature, $900^{\circ}C$ for Roto coal and $950^{\circ}C$ for char, respectively. However, we selected $900^{\circ}C$ as the best operating temperature because the improvement of reactivity of char at $950^{\circ}C$ was negligible. Char represented better reactivity than Roto coal because char contains low volatile than Roto coal. For both solid fuels, reactivities were improved with increasing of the particle diameter. These results were explained by solid mixing tests in a transparent fluidized bed using two char particles having different particle size ranges and OCN703-1100 particle. The bigger particle showed better solid mixing with OCN703-1100 particle, and therefore, represented better reactivity. For both solid fuels, reactivities were improved with increasing of the solid input weight within the experimental conditions of this study because the weight of coarse particles increased with the solid input weight increased, and therefore, these coarse particles can mix well with the oxygen carrier.

• Journal of the Mineralogical Society of Korea
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• v.4 no.1
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• pp.43-50
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• 1991

Two solid solution-type phases has been experimentally found in the quaternary system Cu-Fe-Sn-S:$(Fe, Cu, Sn)_{1+x}$ and $Cu_{2-x}Fe_(1+x}SnS_4$. These solid solutions are stable around the CuS-FeS-SnS referecne plane in the composition tetrahedron. One is the sphalerite-type monosulfide solid solution which has a extensive stability range with varying degrees of sulfur/metal ratio 9.7-1.0/1.0. The other is tetrahedrite-type phase $Cu_{2-y)Fe_{1+y}SnS_4(y_{max}=0.4)$ which is stable along the $Cu_2FeSnS_4-FeS$ tie line, but shows no phase transformation in the subsolidus range and decomposes incongruently at the range of 835-862${\circ}C$, depending on the compositional variation. Particularly, the latter phase shows the characteristic superstructure reflections, indicating that it is a derivative of sphalerite structure. The stability field of these two sphalerite-type phases are defined on the basis of diffraction pattern and optical homogeneity of the synthetic materials at the temperature range of 700-400${\circ}C$.