• Journal of Powder Materials
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• v.1 no.1
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• pp.66-71
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• 1994

Optical microstructures and mechanical properties of Na gas atomized Al-20Si-5Fe alloying powder and its hot extrudates were studied on 3 different types of powder size distribution. This powder showed the size distribution of 10~210 $\mu\textrm{m}$. Also the microstructures of $\alpha$-Al, primary and eutectic Si and needle shaped intermetallic compounds were observed by optical microscope. These needle shaped intermetallic compounds were identified as ${\delta}Al_4FeSi_2$- by XRD and EDX analysis. The ultimate tensile strength(UTS) of these alloy extrudates was increased from 324 to 390 MPa with decreasing powder size range from 120~210 $\mu\textrm{m}$ to 10~64 $\mu\textrm{m}$. A value of Micro-vic-kers hardness was simillar to the result of UTS. These extrudates showed better wear resistance than those of Al-20Si-2X(X : Ni, Cr, Zr), although they are insensitive to the size distribution. These results indicate that the presentation of ${\delta}Al_4FeSi_2$ intermetallic compounds contributed to the wear resistance improvement.

• Journal of the Korean institute of surface engineering
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• v.35 no.4
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• pp.232-240
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• 2002

The composition and the microstructure of the Zn-Cr alloys electroplated in chloride bath with EDTA were studied according to electrolysis conditions. The cathode current efficiency decreased with increasing both Cr/(Cr+Zn) ratio and current density. The Cr content of the alloy deposits increased with Cr/(Cr+Zn) ratio and current density The phase structure of Zn-Cr alloy deposits changed from η-Zn through η-Zn+${\gamma}$'-ZnCr to ${\gamma}$'-ZnCr with increasing Cr content of alloys. The surface morphology of Zn-Cr alloy deposits changed from fine needle shaped crystallites through the mixed structure of needle-shaped and granular one to the colony structure with fine granular crystallites according to the change of phase structure

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1581-1583
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• 2000

In this paper, we proposed a surface discharge FFL with the new electrode structure like the needle shaped electrode as the variation of cell structure to high luminance and low power consumption. In comparison with different electrode structure it has low discharge voltage and current and good optical characteristics. So it has better discharge characteristics than different surface discharge FFL and can be fungible of backlight as a lighting source in LCDs.

• Proceedings of the KIEE Conference
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• 1984.07a
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• pp.230-231
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• 1984

• Journal of Veterinary Clinics
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• v.21 no.2
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• pp.181-183
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• 2004

Hepatic mass was aspirated under the guidance with ultrasound in 9-year old female maltese with signs of anorexia, hematochezia, vomiting, depression, and abdominal distension. Radiographic and abdominal ultrasonographic examinations were performed, which revealed enlarged tubular shaped uterine mass and solitary, small round hyperechoic hepatic mass dorsal to gall bladder as an incidental finding. Ultrasound-guided fine needle aspiration was completed, but histologic confirmation should be made for definitive diagnosis by tissue core or wedge biopsy.

• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.118-124
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• 2004

The properties of AlN made by carbothermal reaction depend on the starting materials, quantity of liquid, the liquid-vapor phase reaction, the N$_2$ flow rate, and the reaction temperature. AlN whisker was synthesized by the VLS and VS methods. Solid ${\alpha}$-A1$_2$O$_3$(AES-11) was carbothermally reduced with carbon black in a high-purity N$_2$ atmosphere with AlF$_3$ to cause whisker grown and additional aluminum liquid to increase whisker yield. Aluminum nitride was perfectly formed at reaction temperatures of 1600$^{\circ}C$. At reaction temperature higher than 1600$^{\circ}C$ the aluminum nitride was completely formed, while the composition remains unaffected. Needle-shaped whiskers formed best at 1600$^{\circ}C$ while higher temperatures disrupted whisker formation. Adding 0 to 15 wt% aluminum to the synthesis favorably affects the microstructure for formation of needle-shaped AlN whisker. Additions over 15 wt% degraded formation of AlN whisker.

• Journal of the Korea Institute of Building Construction
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• v.20 no.5
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• pp.433-440
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• 2020

In this study, a new type of Durometer was invented by modifying the currently used Durometer with the hemisphere shaped needle to columnar shaped needle. The aim of the study is, hence, to provide the feasibility of the advanced Durometer for assessing setting time of the concrete. Generally, the finishing of concrete surface should be conducted to secure the smooth surface, improve the permeability, and prevent the plastic shrinkage cracking. Although this surface finishing work should be conducted during the plastic phase between initial and final setting, currently in practical situations, the timing of starting the finishing work was determined by the sense of the worker. To improve this situation, Kato Junji suggested to use the hemisphere and needle shaped Durometers to determine the initial and final setting time, respectively. However, in this case, there are difficulties of using two different Durometers and of occurring failure of the Durometer due to the intruded cement paste. To prove the feasibility of new typed Durometer, setting time and surface hardness were evaluated by applying for the concrete with various replacing ratios of fly-ash and coal gasification slag as an aggregate.

• Journal of Gastric Cancer
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• v.22 no.3
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• pp.248-259
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• 2022

Purpose: To overcome the technical difficulties of single-incision laparoscopic distal gastrectomy (SILDG), needle grasper (Endo Relief^TM)-assisted SILDG (NASILDG) was developed. Here, we compared the operative convenience and postoperative outcomes between SILDG and NASILDG. Materials and Methods: A needle grasper was inserted into the right upper abdomen and used in the NASILDG. We retrospectively reviewed patients who underwent D1 + dissection and delta-shaped Billroth I anastomosis with SILDG or NASILDG performed by a single surgeon between September 2015 and August 2018. Results: The SILDG (male, 50.0%) and NASILDG (male, 60.0%) groups included 10 and 15 patients, respectively. The operative time without combined operation and anastomosis was significantly shorter in the NASILDG group. Early complications and scar characteristics were not significantly different between the two groups. Conclusions: By adding a needle grasper, SILDG became more convenient without decreasing cosmetic results. NASILDG could be a recommended method to reduce the technical difficulty of SILDG.

• The Korean Journal of Cytopathology
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• v.9 no.1
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• pp.89-94
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• 1998

A case of fine needle aspiration cytology of an osteoclastic giant cell tumor of pancreas, which is an uncommon variant of ductal adenocarcinoma, is described. Aspirated tumor cells were characterized by three populations: (1) bland osteoclast like giant cells with multiple small, round nuclei with distinct nucleoli, and abundant cytoplasm, (2) Individually scattered or loosely clustered medium sized mononuclear tumor cells, having fine chromatin, smooth nuclear membrane, often prominent nucleoli, and high N/C ratio, (3) bland or atypical spindle shaped cells. Osteoid like lacy material was also seen on cell block section. The immunohistochemical studies using paraffin embedded cell block section showed positivities for vimentin and lysozyme in both giant and mononuclear turner cells. However, they were negative for cytokeratin, epithelial membrane antigen, S-100 protein, carcinoembryonic antigen, and p53.

• The Korean Journal of Cytopathology
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• v.13 no.2
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• pp.74-77
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• 2002

Lymphoepithelial carcinoma, also known as malignant lymphoepithelial lesion or lymphoepithelioma, is a rare tumor in salivary glands. Lymphoepithelial carcinoma has a characteristic histological findings comprising irregularly-shaped nests of malignant epithelial cells within a lymphocyte-rich stroma, occasionally forming lymphoid follicles. We recently experienced a case of fine needle aspiration cytology (FNAC) of lymphoepithelial carcinoma of parotid gland in a 61-year-old male. The FNAC yielded a hypercellular smear of many irregular clusters of malignant epithelial cells in the background of lymphoid stroma.