• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.91-95
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• 1996

One must observe abrasive grain of grinding wheel and know their behaviors to understand the grinding mechanism. The behaviors of abrasive grain on the wheel surface. such as shapes distributions and changes were studied to make the grinding mechanism clear but the behaviors of abrasive grains on CBN wheel are not known enough. From this paper the working surface of a grinding wheel is observed by photography in which a picture of a wheel surface is taken by the camera through the microscope on the grinding machine and analyzed with the computer.

• Laser Solutions
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• v.11 no.3
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• pp.16-20
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• 2008

The lap Joint welding of 6K21 aluminum sheets by Nd:YAG laser were performed with an aluminum 5183 filler wire or without a filler wire. The porosity of laser welding beads were observed through an optical microscope and X-ray photography with various levels of welding speed and gap size. The porosity was observed in the gap between upper and lower sheet near a heat affected zone when autogenous welding. Decrease of welding speed and use of AA5183 filler wire reduced porosity significantly.

• 보존과학연구
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• s.15
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• pp.59-103
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• 1994

Painting is well regarded as a stratified structure by the conservators and restorers. Hence, the scientific methods have been developed for the study of the interal layer of paintings. Examples of such methods are X-ray, infra-red, and ultra-violet photography. A more direct method is to look at the painting in cross section under the microscope and to analyze pigments using an electron probe X-ray micro analyzer(EPMA).In this research, I study and analyze twenty two Korean paintings of self-portraits including the first oil painting of Hui Dong Koh's self-portrait stored in the museum of Tokyo National University of Fine Arts and Music, employing these scientific techniques. The small fragments taken from the ground layers of the early oil paintings(1915∼1942)are analyzed using the EPMA. According to their main materials, the ground layers can be classified into five types ; 1. Lead white layer and double layer of calcium carbonate and lead white, 2. Zinc white with some mixiture of lead white, 3.Titanium white with some barium white, 4. Barium white, 5.Double layer of titanium white and zinc white.

• Advanced Composite Materials
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• v.16 no.2
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• pp.151-166
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• 2007

High-cycle fatigue characteristics of quasi-isotropic carbon fiber reinforced plastic (CFRP) laminates [-45/0/45/90]s up to $10^8$ cycles were investigated. To assess the fatigue behavior in the high-cycle region, fatigue tests were conducted at a frequency of 100 Hz, since it is difficult to investigate the fatigue characteristics in high-cycle at 5 Hz. Then, the damage behavior of the specimen was observed with a microscope, soft X-ray photography and a 3D ultrasonic inspection system. In this study, to evaluate quantitative characteristics of both transverse crack propagation and delamination growth in the high-cycle region, the energy release rate associated with damage growth in the width direction was calculated. Transverse crack propagation and delamination growth in the width direction were evaluated based on a modified Paris law approach. The results revealed that transverse crack propagation delayed under the test conditions of less than ${\sigma}_{max}/{\sigma}_b$ = 0.3 of the applied stress level.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1279-1284
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• 2011

Gelatinization properties of crude starches from acorns harvested in various countries (domestic (KAS), Chinese (CAS), and North Korea (NAS)) were analyzed, especially blue value, amylose contents, amylogram, particle size, and SEM (scanning electron microscope). Amylose contents of NAS, KAS, and CAS were 33.65%, 32.00%, and 30.48%, respectively, and a similar tendency was observed in blue value. According to amylogram, initial paste temperature was $72^{\circ}C$ for NAS and CAS and $71^{\circ}C$ for KAS, whereas peak viscosity was 580 BU for KAS and NAS and 570 BU for CAS. The cooling viscosity and setback of NAS and CAS were higher than those of KAS. The average particle size was 23.17 microns for KAS, 23.53 microns for CAS, and 82.14 microns for NAS; particle size ranging from 5~40 microns was highly distributed in KAS (68.9%) and CAS (73.8%), whereas 57.1% distribution was observed for 5~40 microns and 27.2% for >80 microns in NAS. Gelatinization ranges of SEM photography of CAS and NAS showed a more swollen, extremely disintegrated, and folded structure than that of KAS. From these results, gelatinization properties, especially viscosity, setback of amylogram, particle size, and SEM photography, differed according to the country.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.3
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• pp.145-152
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• 1989

Volume phase diffraction grating is formed in 5${mu}m$ Agfa 8E75 photographic emulsion film using He-Ne laser. It is dependent on the chemical processing rather than materials themselves that high diffraction efficiency can obtained in silver halide emulsions. With potassium dichromate bleach and alcohol drying, overall efficiency of 71% (81% after allowing for reflection at the two surfaces) has been achieved at an exposure of 180${mu}J/cm^2.$ Dichromate cross-linkage and air void by rapid dehydration increase refractive index modulation depth. The grating is swollen, which is newly identified by Scanning Electronic Microscope(SEM) photography, and it causes on-Bragg at larger angle than the recording angle. It is pointed out that controlling the emulsion thickness has an important role as a potential source for high diffraction efficiency.

• Culinary science and hospitality research
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• v.15 no.4
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• pp.99-114
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• 2009

This study examined the optimal cooking condition for surimi-like material (SLM) derived from porcine semimembranosus (SM) muscle and the effects of the various cooking temperatures and the cooking time on the gel properties. The most noticeable change that occurred during the preparation of the SLM from the SM was the reduction in the fat content (about 1%) during the washing procedures. The hardness and gel strength value were increased significantly as the cooking temperature was increased by $75^{\circ}C$ for 20 min (p<0.05). The SLMG cooked above $75^{\circ}C$ had a significantly higher WHC than the SLMG cooked below $75^{\circ}C$ (p<0.05). The gelling property of SLMG was effected for different conditions of cooking time and temperatures by the result of SDS-PAGE. After 20 min cooking, some enzyme bands including phosphorylase disappeared. The loss of these bands (about 46 kDa and 60 kDa) was observed after 20 min of cooking time. The photographs of microscopy showed that the filaments of myofibrils did not disappear after a cooking time of 15 min, and that the gaps between the fibers or filament were close. A significant change in the fibers and filaments occurred from 30 min to 35 min of cooking time, and the gradual coagulation of the structure of the SLM was observed with cooking time increased. These results suggest that a desirable surimi gel could be obtained from pork by cooking at $75^{\circ}C$ for 25 min.