• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.643-648
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• 2002

In the cutting of plate steel, the quality of the cut surfaces is strongly dependent on the cutting conditions such as cutting speed, kerf width, plate thickness, length of tip-specimen and oxygen pressure etc. the cutting tests of plate steel were carried out using CNC gas cutting machine. this paper deals with cutting characteristics of plate steel using CNC cutting machine. the width of cutting entrance and exit, the surface roughness of cutting surfaces and the cutting surface are examined at various cutting conditions.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.9-16
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• 2006

A solar collector surface coated with a low emission material is still imported from other developed countries expensively. Thus it is very significant to develop a new coating method with a cheap alternative coating material instead of the imported high-cost collector surface. A thermal spray method was adopted to coat a cheap Titania on a copper plate. Generally, a new coating on the copper plate was conducted successfully by selecting a proper ratio of carbon and acetylene. By measuring an absorption rate of solar and heat emission rate, all the plate types gained a high absorption rate of 98% approximately, more or less, but all of the types still have a high emission. Finally it was clear that more research is needed to advance the coated-plate to subdue the high emission from the hot plate surface and the higher the Titania's proportion is, the lower the emission is on the surface.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.149-154
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• 2003

The cutting tests of high tensile steel plate(AH36) were carried out using CNC plasma arc cutting machine. Both top and bottom width of kerf and the surface roughness(Ra, Rmax) of cut surface are measured under various cutting conditions such as cutting speed, steel plate thickness, etc. In the CNC plasma arc cutting, the surface roughness decreases as cutting speed increases. The hardness is high up to 4mm depth from the cutting surface. In the cutting speed 1300~2100mm/min, the ratio of proper kerf width(Wt/Wb) is around 2.6. Through the series the series of experiments, the satisfactory cutting conditions of high tensile steel plate were found.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.645-649
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• 2009

Liquid desiccant cooling technology can supply cooling by using waste heat and solar heat which are hard to use effectively. For compact and efficient design of a dehumidifier, it is important to sustain sufficient heat and mass transfer surface area for water vapor diffusion from air to liquid desiccant on heat exchanger. In this study, the plate type heat exchanger is adopted which has extended surface, and hydrophilic coating and porous layer coating are adopted to enhance surface wettedness. PP(polypropylene) plate is coated by porous layer and PET(polyethylene terephthalate) non-woven fabric is coated by hydrophilic polymer. These coated surfaces have porous structure, so that falling liquid film spreads widely on the coated surface foaming thin liquid film by capillary force. The temperature of liquid desiccant increases during dehumidification process by latent heat absorption, which leads to loss of dehumidification capacity. Liquid desiccant is cooled by cooling water flowing in plate heat exchanger. On the plate side, the liquid desiccant can be cooled by internal cooling. However the liquid desiccant on extended surface should be moved and cooled at heat exchanger surface. Optimal mixing and distribution of liquid desiccant between extended surface and plate heat exchanger surface is essential design parameter. The experiment has been conducted to verify effective surface treatment and distribution characteristics by measuring wall side flow rate and visualization test. It is observed that hydrophilic and porous layer coating have excellent wettedness, and the distribution can be regulated by adopting holes on extended surface.

• Korean Journal of Materials Research
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• v.32 no.10
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• pp.414-418
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• 2022

Magnesium alloy is the lightest practical metal. It has excellent specific strength and recyclability as well as abundant reserves, and is expected to be a next-generation structural metal material following aluminum alloy. This paper investigated the possibility of thin plate fabrication by applying a overheating treatment to the melt drag method, and investigating the surface shape of the thin plate, grain size, grain size distribution, and Vickers hardness. When the overheating treatment was applied to magnesium alloy, the grains were refined, so it is expected that further refinement of grains can be realized if the overheating treatment is applied to the melt drag method. By applying overheating treatment, it was possible to fabricate a thin plate of magnesium alloy using the melt drag method, and a microstructure with a minimum grain size of around 12 ㎛ was obtained. As the overheating treatment temperature increased, void defects increased on the roll surface of the thin plate, and holding time had no effect on the surface shape of the thin plate. The fabricated thin plate showed uniform grain size distribution. When the holding times were 0 and 30 min, the grain size was refined, and the effect of the holding time became smaller as the overheating treatment temperature increased. As the overheating temperature becomes higher, the grain size becomes finer, and the finer the grain size is, the higher the Vickers hardness.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.2
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• pp.59-70
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• 2011

Even though we could not count the total amount of plates in Korean printing industry per year, we would suppose the total amount of plates about $20,000km^2$ to $22,000km^2$ per year through our printing experience. On the standard of the end of 2010, it would be the market share of plates are that CTP plate is $9,000km^2$, CTcP plate is$4,000km^2$ and PS plate is $9,000km^2$, such as total amount of plates are $22,000km^2$. When there was no installed CTP setter in Korea, the domestic plate would be over 60% market share of plate in Korean printing industry. But now it would be less than 25% market share of plate. It is necessary to develop domestic CTP thermal plate from now because we have to keep the market share of domestic plate. On the study of the surface structure of substrate, roughness, anodized layer amount and coating amount between domestic CTP thermal plate and foreign CTP thermal plate, it would be the basic to develop domestic CTP thermal plate.

• Journal of Korean Society of Steel Construction
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• v.28 no.3
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• pp.129-138
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• 2016

Buckling of surface plates is an important limit state in Steel-Plate Concrete (SC) walls under axial compression. The surface plates may be anchored to concrete using connectors of studs or tie-bars. In this paper, the effects of studs and tie-bars on buckling of surface plates were evaluated by conducting tests. Experiments have three types of connectors; all studs, all tie-bars, and the combination of studs and tie-bars. Also, experiments have the various ratios of stud or tie-bar spacing to surface plate thickness. The experimental investigation shows that the buckling shape and strength of the surface plate of SC wall with the combination of studs and tie-bars have good agreements with that of the surface plate of SC walls with all studs or all tie-bars.

• Publications of The Korean Astronomical Society
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• v.10 no.1
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• pp.31-55
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• 1995

We have developed a new device, Plate-to-CCD Convertor (PCC), to conveniently digitize photographic plates in a relatively short time without losing any plate information (Oh et al. 1995). Using this device we have performed surface photometry of 12 early type galaxies. We determined relative orientations and scales to analyze PCC images. We also determined an ellipticity, position angle of the major axis, and $a_4$ of each galaxy to quantify the distribution of surface brightness. We checked the performance and limitation of this device by comparing the PCC images with those digitized by the ST microdensitometer and those obtained with CCD observations.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.2
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• pp.104-109
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• 2006

In this study, the equivalent plate model is developed using a finite element method(FEM) based on the first order shear deformation theory(FSDT). The substructure synthesis method is used to consider the control surface. For the verification of the equivalent model, the results of free vibration analysis are compared with the ones of 3D wing structure modeled by using the MSC/NASTRAN.

• Bulletin of the Korean Chemical Society
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• v.21 no.4
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• pp.401-404
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• 2000

Matrix/Surface-assisted laser desorption/ionization (M/SALDI) mass spectrometry of polypropylene glycol and polystyrene, directly deposited on graphite plate, is demonstrated. Graphite plate is effective both as an en-ergy transfer medium and robu st sampling support for LDI of polymers. Mass spectra ofpolymers can be easily obtained due to homogeneous distribution on graphite surface and their ion signals are long-lived by large ef-fective desorption volume enough to investigate M/SALDI process.