• Journal of Surface Science and Engineering
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• v.40 no.3
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• pp.107-112
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• 2007

Aluminum doped zinc oxide (AZO) films were deposited on non-alkali glass substrate by DC magnetron sputtering with 3 types of AZO targets (doped with 1.0 wt%, 2.0 wt%, 3.0 wt% $Al_2O_3$). Electrical, optical properties and microstructure of AZO films have been investigated by Hall effect measurements, UV/VIS/NIR spectrophotometer, and XRD, respectively. Crystallinity of AZO films increased with increasing substrate temperature ($T_s$) and doping ratio of Al. Resistivity and optical transmittance in visible light were $8.8{\times}10^{-4}{\Omega}cm$ and above 85%, respectively, for the AZO film deposited using AZO target (doped with 3.0 wt% $Al_2O_3$) at $T_s$ of $300^{\circ}C$. On the other hand, transmittance of AZO films in near-infrared region decreased with increasing $T_s$ and doping ratio of Al, which could be attributed to the increase of carrier density.

• Korean Journal of Materials Research
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• v.19 no.8
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• pp.407-411
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• 2009

Reflection properties, such as specular reflection and diffuse reflection, are very important optical properties for the reflector, which has high reflectance in the display and architecture industry. Calcite is lowcost, nontoxic, and stable over a wide temperature range. Therefore, it is one of the most widely using fillers in many industries and has some advantages over titania as a filler to improve reflectance. However, optical properties, especially those of ceramic-filled composites, have not been analyzed. We studied the reflectance of calcite composites with their surface roughness. The reflectance of the composites was determined using a UV-visible spectrometer. The surface morphology and the micro-structure of the composites were investigated by atomic force microscope. The reflectance of the composites was improved by increasing the content of calcite in the calcite-frit composite. The reflectance is related with the surface roughness in the composites. However, the reflectance depends on the calcite contents in materials with similar surface roughness.

• The Korean Journal of Ceramics
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• v.1 no.4
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• pp.191-196
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• 1995

Using sol-gel processing method, thin films of lathanum modified lead titanate(PLT) on Corning 7059 glass were prepared. A differential thermal analysis (DTA/TG) curve of gel powder and infrared spectra (FT-IR) of the films were measured to estimate residual organices in them. The heat-treated films were characterized by X-ray diffraction(XRD). Microstructures of the films were observed by a scanning electron microscope (SEM). Optical properties of the films were determined by a UV-VIS spectrophotometer. The waveguiding properties and optical attenuation were measured with the end coupling method and the cut back method. Effects of the drying conditions on the transmittance and the propagation loss of the films were investigated. Experimemtal results showed that the content of residual organics in the film decreased as the drying temperature of the film increased. As the La content of the film increased, the grain size decreased and the transmittance increased. The transmittances of the films increased with the increasing of the drying temperature. The propagation losses in the film decreased as the drying temperature increased.

• The Korean Journal of Ceramics
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• v.6 no.4
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• pp.354-358
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• 2000

The SnO$_2$film was deposited on a corning glass 1737 substrate by plasma enhanced chemical vapor deposition using a gas mixture of SnCl$_4$, $O_2$, and Ar. The film thickness was measured using $\alpha$-step and was about 9400$\AA$. The conventional X-ray diffractometry and pole figure attachment were used to refine the crystal structure of SnO$_2$ thin film. Six pole figures, (200), (211), (310), (301), (321), and (411), were measured with CoK$_\alpha$ radiation in reflection geometry. The X-ray diffraction data were measured at room temperature using CuK$_\alpha$ radiation with graphite monochromator. The agreement between calculated and observed patterns for the normal direction of SnO$_2$ thin film was not satisfactory due to the severely preferred orientation effect. The Rietveld refinement of heavily textured SnO$_2$ thin film was successfully achieved by adopting the pole density distribution of each reflection obtained from the inverse pole figure as a correction factor for the preferred orientation effect. The R-weighted pattern, R$_wp$, was 15.30%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.10
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• pp.1976-1981
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• 2009

Transparent conducting aluminum-doped zinc oxide (AZO) thin films were deposited on Coming glass substrate using an Gun-type rf magnetron sputtering deposition technology. The AZO thin films were fabricated with an AZO ceramic target (Zn: 98wt.%, $Al_2O_3$: 2wt.%). The AZO thin films were deposited with various growth conditions such as the substrate temperature, oxygen pressure. X -ray diffraction (XRD), UV/visible spectroscope, atomic force microscope (AFM), and Hall effect measurement system were done in order to investigate the properties of the AZO thin films Among the AZO thin films prepared in this study, the one formed at conditions of the substrate temperature $100^{\circ}C$, Ar 50 sccm, $O_2$ 5 sccm and working pressure 5 motor showed the best properties of an electrical resistivity of $1.763{\times}10^{-4}\;[{\Omega}{\cdot}cm]$, a carrier concentration of $1.801{\times}10^{21}\;[cm^{-3}]$, and a carrier mobility of $19.66\;[cm^2/V{\cdot}S]$, which indicates that it could be used as a transparent electrode for thin film transistor and flat panel display applications.

• Environmental Engineering Research
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• v.23 no.3
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• pp.323-329
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• 2018

The municipal solid waste (MSW) management system in one of the Class II Indian cities i.e. Rishikesh was studied and analysed to identify the key issues in solid waste management in the city. A total of 329 solid waste samples from 47 households were collected to characterize the household solid waste (HSW). The average (HSW) generation rate was 0.26 kg/c/d and it was composed of organic waste (57.3%), plastics (14%), paper (10.9%), and glass and ceramic (1.3%) and other materials (16.5%). There was an inverse relationship between household waste generation rate and family size (p < 0.05). The MSW management system practiced in Rishikesh is unsound. There is no waste segregation at source, no provisions of composting and no recycling by formal sector. The collection and transportation of waste is inadequate and inappropriate. Collected waste is dumped in open dumping site without scientific management. Following are some recommendations for developing a sustainable solid waste management system in Rishikesh city: (1) sensitize people for segregation at source; (2) promote reduction, reuse and recycling of wastes; (3) promote community based composting; (4) provision for 100% door to door collection and; (5) formalize the informal sectors such as rag pickers and recycling industries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.771-777
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• 2006

Recently regulations which make it mandatory to use the environment-friendly goods are increaing in automobiles. In this study the TIG autogenous welding process was developed by solving the problem of previous spot welding of side part and the ceramic protection Jig was developed for the welding of fragile glass ball. And the optimal process parameter was selected by complementing the demerit of the previous filler material welding to fill up the bottom part. Finally the lamp aging test and earthquake resistant test was done to check the reliability of welded brake lamp.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.262-263
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• 2007

Effect of co-doping on optical and electrical properties of $SnO_2$ based thin films were studied. $SnO_2$ ceramic targets with up to 50mol% $CuSb_2O_6$ were prepared by sintering mixed-oxide compact in the temperature range of $1100^{\circ}C{\sim}1300^{\circ}C$ in air. Thin films were then deposited onto glass substrates by pulsed laser deposition where substrate temperature was maintained in the range of $500{\sim}650^{\circ}C$ with oxygen pressure of 3m~7.5mTorr and energy density of $1Jcm^{-2}$. It was found that with the increase amount of dopant, the electrical properties of thin films tended to improve with the smallest resistivity value obtained at about 8mol% doping, further increase, however, usually impaired the optical transmission in the visible range.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.3
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• pp.215-218
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• 2011

A novel design of gas sensor using Ga-doped ZnO (GZO) thin films which are deposited on low temperature co-fired ceramic (LTCC) substrates is presented. The LTCC substrates with thickness of 400 ${\mu}m$ are fabricated by laminating 12 green tapes which consist of alumina and glass particle in an organic binder. The GZO thin films with different thickness are deposited on LTCC substrates, by RF magnetron sputtering method. The microstructure and sensing properties of GZO gas sensing films are analyzed as a function of the film thickness. The films are well crystallized in the hexagonal (wurzite) structure with increasing thickness. The maximum sensitivity of 3.49 is obtained at 100 nm film thickness and the fastest 90% response time of 27.2 sec is obtained at 50 nm film thickness for the operating temperature of $400^{\circ}C$ to the $NO_2$ gas.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.425-435
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• 2019

Purpose: The purpose of this study was to resolve the Naval ship's Local Operation Panel(LOP) malfunction problems which caused by overheating in summer season and dispatching to equatorial regions. Methods: Instead of using dual type heat insulation materials(consist with ceramic wool and glass wool), aerogel heat insulation materials were used for decreasing heat emissions from gas-turbine heat waste steam pipes passing water-jet- room. Experiment and Computational analysis of heat flow were conducted to analyze the internal room temperature changes. Results: The results of this study are as follows; The aerogel heat insulation materials suppress heat emission more efficiently than dual type insulation materials. The cold surface temperature of insulation was far more decreased and internal room, LOP surface temperature also showed significant results too. Conclusion: The substituted heat insulation materials appeared remarkable performance in decreasing room temperature that it could be used for suppressing the LOP overheatings and malfunctions.