• The Korean Journal of Cytopathology
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• 제5권1호
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• pp.65-70
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• 1994

We describe a case of fine needle aspiration cytology of renal angiomyolipoma which was not associated with the clinical complex of tuberous sclerosis and was incidentally found. It was a solitary lesion and the clinical impression before needle aspiration was renal ceil carcinoma. The aspirated specimen showed mature fat cells, clusters of renal tubular epithelial cells and sheets of pleomorphic smooth muscle cells with fibrillary cytoplasm. The nuclei of smooth muscle celis varied in size and shape. Since the treatment of renal angiomyolipoma differs from that of renal ceil carcinoma, the preoperative cytological diagnosis is of great value.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제31권11호
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• pp.1108-1114
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• 2007

The low kinds of $Al_2O_3$ composite ceramics were prepared using a mixture of 85 wt.% $Al_2O_3$ (mean size $0.5\;{\mu}m$), 15 wt.% SiC Powder with $Y_2O_3$, as an additive powder (0, 1, 3 and 5 wt.%). The crack-healing strengths were studied as functions of crack-healing temperature and amount of $Y_2O_3$. The in-situ crack-healing behavior was observed at 1,573 K for 1 h in the air. The heat treated specimen with 3 wt.% of $Y_2O_3$ showed better crack-healing ability than specimen with 1 or 5 wt.% of $Y_2O_3$. In case of specimen with 3 wt.% of $Y_2O_3$, the bending strength of the crack-healed specimen at 1,473 K was recovered to the bending strength of smooth specimen treated at 1573 K. The heat-resistance limit temperature of $Al_2O_3$ composite ceramics was 1,073 K, 1,373 K, 873 K for the specimen with 1, 3, 5 wt.% of $Y_2O_3$.

• Applied Microscopy
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• 제45권4호
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• pp.189-194
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• 2015

Backside Ar ion milling technique for the preparation of cross-sectional transmission electron microscopy (TEM) specimens, and backside-ion milling combined with focused ion beam (FIB) operation for electron holography were introduced in this paper. The backside Ar ion milling technique offers advantages in preparing cross-sectional specimens having thin, smooth and uniform surfaces with low surface damages. The back-side ion milling combined with the FIB technique could be used to observe the two-dimensional p-n junction profiles in semiconductors with the sample quality sufficient for an electron holography study. These techniques have useful applications for accurate TEM analysis of the microstructure of materials or electronic devices such as arrayed hole patterns, three-dimensional integrated circuits, and also relatively thick layers (> $1{\mu}m$).

• Transactions of the Korean Society of Mechanical Engineers
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• 제17권9호
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• pp.2145-2152
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• 1993

The objective of this paper is to examine the detection limit, growth characteristics and notch curvature radius in short crack problem. Measurement techniques such as ultrasonic method and back-face strain compliance method were adopted. The fatigue crack growth rate of the short crack is slower than that of a long crack for a notched specimen. The characteristic of crack growth and crack closure is same as the case of a delay of crack growth caused by constant amplitude load for an ideal crack or single peak overload for a fatigue crack. The short crack is detected effectively by ultrasonic method. A short surface crack occurs in the middle of specimen thickness and is transient to a through crack depth is larger than the notch curvature radius.

• 전기의세계
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• 제25권6호
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• pp.74-80
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• 1976

The temperature rise of the mortars while are being irradiated by ultrasonic waves and immersed in a liquid medium, are measured. The mixing ratios of sand to cement are varied for the different mortars. The results of the experiment are as follows, 1. The temperature rise of the mortar is decreased as themixing ration (S/C) is increased. 2. Thd temperature rise of the specimen is increased as its length is increased. 3. The surface conditions, either smooth or rough, may not have much influence on the temperature rise of the mortar. 4. The initial slope of temperature rise may not have much effect of the viscosity of liquid. The results, describes above, appear well coincide with the theory that the temperature rise is attributed mainly to the absorption heating. Since the absorption heating of the mortars varies with the mixing ratios of sand to cement, the strength of them would be estimated by means of irradiation of ultrasonic waves on the specimen.

• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.305-313
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• 2010

HDPE smooth and textured GMs were cut into dumbbell shape and notched where depth of the notch produced a ligament thickness of 90% to 10% of the nominal thickness of the specimen at 10% interval. Yield stress and elongation were measured of those samples and plotted on Graph. Yield stress and elongation at yield point decreases gradually as the notch depth is increased. Both installations damaged and notched GMs were used to understand stress crack behavior. Intact sample were notched in such a manner that the depth of notch produced a ligament thickness of 80% of the nominal thickness of the specimen. Installation damaged samples were not notched. Stress Crack Resistance behavior was observed using NCTL Test at $50{\pm}1^{\circ}C$ at different yield stresses immerging with pH 4 and pH 12 buffer solutions. Significant difference was observed in both cases.

• Parasites, Hosts and Diseases
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• 제55권5호
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• pp.565-568
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• 2017

An oval-shaped mass with a smooth surface was found in the ear canal of a 22-month-old male infant. Although the mass appeared to be almost entirely blocking the ear canal, it was successfully removed under a surgical microscope without general anesthesia at the outpatient department. Under an optical microscope with hematoxylin and eosin staining, the specimen was observed to have a cuticle with a serrated surface and a pore canal, as well as parts of the capitulum, salivary glands, muscles, midgut, and the legs. The specimen was identified as a hard tick of the family Ixodidae, based on gross and histological findings. This paper is the first report in Korea on the diagnosis and treatment of a tick bite in the ear canal.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• 제4권4호
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• pp.42-49
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• 1995

It is not clearly known how defects or inclusions of a low carbon steel affect a fatigue strength. We study this issue using SM15C materials. The investigation is carried out by a quantitative evaluation, and experimental findings are: (1) a fatigue limit of A series smooth specimen is 205MPa, and that of B, C, D series is 245MPa, 304MPa and 245MPa, respectively. (2) the fatigue limit varies with respects to the stress distribution I the vicinity of a defects and crack. (3) the micro hole creates a half-circular shape crack, while the hole depth is not critical to the fatigue strength, (4) considering the fatigue strength, the hole diameter is more significant than the hole depth, and (5) Fatigue limit of artificially defected specimen is lower than that of a flawless one (5-10%), however, there exist allowance size and depth of defect which don't get to influence at fatigue limit.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• 제7권5호
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• pp.120-126
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• 1998

Second step shot peening was applied on both smooth specimen and U-notch specimen in order to investigate the stress distribution and the improvement in fatigue strength. Various experiments and measurements such as rotary bending fatigue test and the measurement of compressive residual stress were performed. The results showed that the fatigue strength of second step shot peened specimens increased by 34 percent compared to that of unpeened ones. Compressive residual stress also considerably increased, which resulted in the increase of fatigue strength. finite element analysis showed that shot peening is effective in decreasing the bending stress by external force. The effectiveness of shot peening in reducing the compressive residual stress was anticipated by the superposition of the concentrated stress and the compressive residual stress.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.244-245
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• 2006

This paper investigates the characteristic of single-layered and multi-layered compacts made by selective laser sintering using titanium powder (TILOP45 and TILOP150, Sumitomo Titanium Corp.) There were few defects in smooth surface of laser sintered specimen in vacuum as compared to the laser sintered specimen in argon. Maximum tensile strength of singlelayered compact was about 200MPa. Multi-layered compacts show the density of around 75% and the adhesive bonding was not observed between layers, resulted in 70MPa of maximum bending strength and 50MPa of maximum tensile strength.