• Journal of the Korean Ceramic Society
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• v.43 no.6 s.289
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• pp.369-375
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• 2006

[ $(Ba_{0.5}Sr_{0.5})_{0.99}Co_{x}Fe_{1-x}O_{3-{\delta}}$ ] [x=0.8, 0.2](BSCF) powders were synthesized by a Glycine-Nitrate Process (GNP) and the electrochemical performance of the BSCF cathode on a scandia stabilized zirconia, $[(Sc_{2}O_3)_{0.11}(ZrO_2)_{0.89}]-1Al_{2}O_3$ was investigated. In order to prevent unfavorable solid-state reactions between the cathode and zirconia electrolyte, a GDC ($Gd_{0.1}Ce_{0.9}O_{2-{delta}}$) buffer layer was applied on ScSZ. The BSCF (x = 0.8) cathode formed on GDC(Buffer)/ScSZ(Disk) showed poor electrochemical property, because the BSCF cathode layer peeled off after the heat-treatment. On the other hand, there were no delamination or peel off between the BSCF and GDC buffer layer, and the BSCF (x = 0.2) cathode exhibited fairly good electrochemical performances. It was considered that the observed phenomenon was associated with the thermal expansion mismatch between the cathode and buffer layer. The ohmic resistance of the double layer cathode was slightly lower than that of the single layer BSCF cathode due to the incorporation of platinum particle into the BSCF second layer.

• Journal of Environmental Science International
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• v.27 no.2
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• pp.91-97
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• 2018

This study carried out first a component survey on the domestic waste shipped into a waste disposal facility in B city, and then heavy metal analysis of each component according to the SRF standards. Based on this, this study explored the problems with domestic waste and measures to improve them. The results are as follows. The result of the survey of physical components show that paper accounted for the largest proportion with 20.5 %~59.9 %, metals (including batteries) among incombustibles accounted for 0.0~8.3 %, other inorganic substances, glass and ceramics accounted for 0.0~43.7 % and 0.0 %~19.6 % respectively. However, the proportion of coated viny and plastics, which have high lead and cadmium content, was rather high with 2.9 %~30.9 %. This suggests the possibility that actual concentration of lead and cadmium within SRF is likely to be higher. Among the 15 components contained in the waste brought into the waste disposal facility, 10 components (food waste, textiles, vinyl, plastics, wood, rubber and leather, paper, metals, electronic substrates, and nail polish) were analyzed according to assay samples (approximately 0.1 g and 0.3 g). The result of analysis shows that the amount of Cd and Pb detected in coated vinyl for 0.109 g of assay sample was 98.6 mg/kg and 20.6 mg/kg respectively; 117.0 mg/kg and 29.0 mg/kg respectively for 0.313 g of assay sample. This is high contents exceeding the Cd standard. As for wooden component, the amount of Pb was 480.0 mg/kg for 0.3 g of assay sample. This suggests that there always exists the possibility of exceeding the exposure level of heavy metals (Cd and Pb) in SRF as long as coated wood and vinyl plastics with high contents of Pb and Cd are shipped into the waste disposal facility; and the local government and the residents need to work hard to improve the situation including development of the machine to sort electronic substrates and batteries for separate collection of the waste of coated vinyl and plastics within domestic waste.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.1
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• pp.116-123
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• 2019

Thermal batteries are also called molten-salt batteries as the electrolyte is mainly composed of molten salt. The molten-salt electrolyte is a solid that does not conduct electricity at room temperature, but when it is melted by a pyrotechnic heat source, it becomes an excellent ionic conductor. Thermal batteries are a kind of pyrotechnic battery because they operate only when the solid electrolyte is melted by the heat energy provided by pyrotechnic materials. Pyrotechnic components used in a thermal battery include heat sources, fuse strips, and an igniter. The reliability of these pyrotechnic components critically affects the reliability and performance of the battery that must supply electricity stably to guided munitions even under extreme environmental conditions. Different igniter types offer different advantages: notch-type igniters offer improved ignition probability, whereas film-type igniters offer improved safety. The addition of metal oxides to the heat paper could improve the burn rate, and the ignition reliability could be greatly improved by using it with a flame igniter at the same time. Using a two-step reduction process, high-purity Fe particles in coral form can be safely obtained.

• New Physics: Sae Mulli
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• v.68 no.11
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• pp.1167-1172
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• 2018

Carbon nanotubes (CNTs) are structures of carbon atoms bonded together in hexagonal honeycomb shapes, with multi-walled CNTs having a very high thermal conductivity of $3000W/m{\cdot}K$ and single-walled CNTs having a conductivity of $6000W/m{\cdot}K$. In this work, the transmittance and the thermal diffusivity of a multi-walled carbon nanotube dispersion with a concentration of 1.5 M were measured using a single beam method, a dual beam method, and the thermal lens effect. The nonlinear optical coefficients were obtained by using the z-scan method, which moved the sample in the direction of propagation of the single laser beam, propagation and the thermal diffusivity was measured using a double laser beam. As a pump beam, a diode-pumped solid state (DPSS) laser with a wavelength of 532 nm and an intensity of 100 mW was used. As the probe beam, a He-Ne laser having a wavelength of 633 nm and an intensity of 5 mW was used. The experimental result shows that when the concentrations of the sample were 9.99, 11.10, 16.65, and 19.98 mM, the nonlinear absorption coefficients were 0.046, 0.051, 0.136 and 0.169 m/W, respectively. Also, the nonlinear refractive indices were 0.20, 0.51, 1.25 and $1.32{\times}10^{-11}m^2/W$, respectively, and the average thermal diffusivity was $1.33{\times}10^{-6}m^2/s$.

• Resources Recycling
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• v.16 no.3 s.77
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• pp.19-26
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• 2007

The bottom ash of municipal solid waste incineration generated during incineration of municipal solid waste in metropolitan area consists of ceramics, glasses, ferrous materials, combustible materials and food waste and so on. Although the ferrous material was separated by the magnetic separation before the incineration process, of which content accounts for about $3{\sim}11%$ in bottom ash. The formation of a $Fe_3O_4-Fe_2O_3$ double layer(similar to pure Fe) on the iron surface was found during air-annealing in the incinerator at $1000^{\circ}C$. A strong thermal shock, such as that takes place during water-cooling of bottom ash, leads to the breakdown of this oxidation layer, facilitating the degradation of ferrous metals and the formation of corrosion products and it existed as $Fe_2O_3,\;Fe_3O_4\;and\;FeS_2$. So, many problems could occur in the use of bottom ash as an aggregate substitutes in construction field. Therefore, in this study, the separation of ferrous materials from municipal solid waste incineration bottom ash was investigated. In the result, the ferrous product(such as $Fe_2O_3,\;Fe_3O_4,\;FeS_2$ and iron) by magnetic separator at 3800 gauss per total bottom ash(w/w.%) accounted for about 18.7%, and 87.7% of the ferrous product was in the size over 1.18 mm. Also the iron per total bottom ash accounted for about 3.8% and the majority of it was in the size over 1.18 mm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4087-4092
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• 2014

The gangway connection of the articulated high speed railway vehicles (HSRV) is a double wrinkled rubber component to seal the air of the corridor under a range of angular deviations between the carriage end parts. From the results of non-linear structural analysis, one of the severe loading conditions for the connection is mixed mode (rolling+yawing) angular displacements while passing through the small-radius curved siding track of the HSRV depot. In this study, to ensure the safety enhancement of the component, the optimal design for the cross section of that was performed using the Solid Isotropic Material with Penalization (SIMP) method. Nonlinear finite element analysis confirmed that the decreases in the maximum principal strain of the optimized design under rolling and mixed modes are 68% and 39%, respectively, compared to the initial design.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.6 no.1
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• pp.47-52
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• 2000

This study was measured weight loss, total ascorbic acid, titratable acidity, and soluble solids content to investigate the effect of EPS(expanded polystyrene foam) box, LDPE film pouches and double wall corrugated fiberboard box during storage at $20^{\circ}C$. Weight loss of apple packed with corrugated paperboard box after 40 days storage was 5.7%, and those of LDPE, CE film and EPS box were 0.2-0.5%. Ascorbic acid content of apple packed with LDPE, CE, EPS was higher than that of control. Titratable acidity and total soluble solid content of control were changed 40% and 10%, and the EPS were changed 27% and 4%, respectively. Overall appearances of 'Fuji' apple packed with LDFE, CE and EPS were better than that of control.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.529-536
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• 1994

To establish more specific and simple diagnostic methods for detection of the antibodies and antigens of Aujeszky's disease virus(ADV), we designed indirect dot-immunoassay(IDI) and double sandwich dotimmunoassay(DSDI) using the solid phases of nitrocellolose paper and polystyrene plate. The diagnostic efficacy of these methods was investigated. As the sensitivity of IDI was tested by various virus concentration, the specimens with the virus titer above $10^{4.0}TCID_{50}/0.2ml$ showed positive reaction, but that below $10^{1.0}TCID_{50}/ml$ revealed negative. Tonsil emulsion at the virus titer of $10^{4.5}TCID_{50}/0.2ml$ showed the highest sensitivity as diluted by 1/100. In detection of ADV antigens from the various tissues of the rats and pigs infected with ADV, IDI using monoclonal antibody showed the higher specificity as compared with IDI using polyclonal antibody and virus isolation method. The efficacy of the DSDI for detection of ADV antibody was compared with other tests. The sensitivity of DSDI was higher than virus neutralization(VN) and agar gel immunodiffusion test(AGID). Meanwhile, specificity of DSDI was lower than AGID, but similar to IDEA. In comparison with VN test, DSDI showed 96.9% agreement to VN test that is the highest of three tests. In general, application of polyclonal antibody in both tests caused the higher sensitivity but the lower specificty.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.4041-4046
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• 2010

Wholly aromatic polyesters having flexible alkoxy side chain were synthesized by direct polycondensation. The synthetic polymers have been characterized by $^1H$-NMR, FT-IR. DSC, TGA, optical polarizing microscope and X-ray diffractometer. The inherent viscosities (${\eta}_{inh}$) measured in 1,1,2,2-tetrachloroethane (TCE) were 0.46~2.41 dL/g. The polymers having side chain showed double melting transition, ie, solid-sanidic liquid crystalline (LC) phase transition ($T_{m1}$) and sanidic LC phase-nematic LC phase transition ($T_{m2}$). As incresing length of alkoxy side chain, phase transition temperatures decreased and solubilities in organic solvents incresed. The peaks of $2{\theta}\;{\simeq}5$ and $2{\theta}\;{\simeq}20$ in X-ray diffractograms are due to crystallization of polymer main chain and of long side chain, respectively.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.6
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• pp.732-742
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• 1985

Measurements of mean velocity and turbulence characteristics are obtained with a linearized constant temperature hot-wire anemometer in a two-dimensional turbulent jet discharging parallel to a flate. Wall static pressure distribution is also measure. The Reynolds number based on the jet nozzle width (D) is about 42,000 and the step height is 2.5D. The reattachment length is found to be 7.5D by using both wool tuft and oil methods. Upstream of the reattachment point, there exist double coherent structures and mean velocity, Reynolds stresses and triple product profiles are asymmetric about jet center line due to the influence of streamline curvature and recirculating flow region. Near the reattachment point, wall static pressure and turbulence quantities change its shape rapidly because of the large eddies by the solid wall. Especially, turbulence intensity has a maximum value in the reattachment regin, then decreases slowly in the redeveloping wall jet ragion. Downstream of X/D=14, a single large scale eddy structure is formed. Far downstream affer the reattachment(X/D.geq.18) mean velocity profile, the decay of maximum velocity and the variation of jet half width are nearly similar to those of plane wall jet, but the Reynolds stresses are higher than those of the latter.