• 제목/요약/키워드: Elongated

검색결과 1,032건 처리시간 0.026초

A new record of the species Caprella arimotoi (Crustacea: Amphipoda: Caprellidae) from Korean waters

  • Heo, Jun-Haeng;Choi, Jaehong;Kim, Young-Hyo
    • Journal of Species Research
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    • 제9권4호
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    • pp.443-447
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    • 2020
  • A newly recorded species Caprella arimotoi Takeuchi, 1993, belonging to the family Caprellidae Leach, 1814, was collected from the South Sea, Korea. This species is morphologically very similar to Caprella verrucosa Boeck, 1871, with blunt dorsal projections on pereonites, oval-shaped propodus on gnathopod 2, and grasping spines on the pereopods 5-7. Caprella arimotoi originated from C. verrucosa and are difficult to distinguish because they have mixed characteristics. However, C. arimotoi was classified because of several morphological differences. The newly recorded species C. arimotoi is discernible from C. verrucosa by a forwardly curved anterodorsal projection on head, elongated gills, slender pereopod 7, and lacking ventrolateral projections on pereonites 2-7. To date, C. arimotoi has only been reported in Japanese waters. So, our record is the first record in Korean waters and outside of Japan. In this study, the Korean C. arimotoi is illustrated based on the mature male specimens with a brief description of the female, focusing on the sexually dimorphic characters.

자동차용 중공드라이브 샤프트의 성형공정 연구 (Forming Process of the Automotive TDS (Tube Drive Shaft) by the Rotary Swaging Process)

  • 임성주;이낙규;오태원;이지환
    • 소성∙가공
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    • 제12권6호
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    • pp.558-565
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    • 2003
  • Rotary swaging is one of the incremental forming process which is a chipless metal forming process for the reduction of cross-sections of bars, tubes and wires. In the present work, the rotary swaging machine and dies were designed to investigate the formability of TDS(Tube Drive Shaft) used in automotive industry. The process variables such as the speed of forming, the shape of the formed materials and the reduction of area were also estimated to study experimental analyses of rotary swaging process using the materials of 34Mn5 and S45C. From experimental results, it was found that the process variables affected the quality of TDS in terms of hardness, the precision of products and the surface roughness. The hardness after swaging approved to be Increased with the increase in the reduction of diameter. And it was found that the grain size became smaller and the elongated grains were formed in the axis direction.

개에서 발생한 자궁경부 평활근종 (Leiomyoma of the Uterine Cervix in Two Dogs)

  • 조호성;조경오;박남용
    • 한국수의병리학회지
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    • 제5권2호
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    • pp.71-74
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    • 2001
  • Masses of the uterine cervix were detected from two dogs, being a 2-year-old female Yorkshire tarrier and a 12-year-old female Basset Hound. Grossly, the masses measuring 3.O$\times$3.O$\times$4.0 cm and 12.O$\times$l2.O$\times$10.07m were prominent, sharply circumscribed, fleshy tumors in the uterine cervix. Histologically, the masses consisted of smooth muscle cells interwoven in bundles, some of which were cut longitudinally (elongated nuclei) and others transversely. Tumor cell nuclei were ordinarily cigar shaped and had rounded blunt ends in the longitudinal plane. There were low mitotic figures without abnormal ones. From these results, these cases were diagnosed as leiomyoma of the uterine cervix. To our Knowledge, no similar tumors have been reported in the uterine cervix.

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High Toughness Silicon Nitride Material in Machining of Compacted Graphite Iron

  • Park, Kwon-Hee;Lee, Kern-Woo;Lee, Joo-Wan;Sharon, Moshe
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.861-862
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    • 2006
  • The suitable tools for CGI material has not been developed yet because of high hardness, high toughness and very low machininability compared to the grey cast iron. And the tool life has been decreased as the contents of Ti in CGI material. From this research, we were able to do the high speed machining by using high toughness silicon nitride ceramic tools. The silicon nitride ceramic tool grade was specially designed and prepared with microstructure of elongated grains with higher aspect ratio (c/a) than conventional one.

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Preparation and Characterization of Nickel(Ⅱ) and Copper(Ⅱ) Tetaaza Macrocyclic Complexes with Isonicotinate Ligands

  • Choi, Ki-Young;Kim, Moon-Jip;Kim, Dae-Sue;Kim, Yong-Son;Kim, Jae-Hyun;Ryu, Hai-Il;Lim, Youn-Mook;Kang, Seung-Gu;Shin, Ueon-Sang;Lee, Kyu-Chul;Hong, Choon-Pyo
    • Bulletin of the Korean Chemical Society
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    • 제23권8호
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    • pp.1062-1066
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    • 2002
  • The complexes [Ni(L)(INT)2]${\cdot}$5H2O (1) and [Cu(L)(H2O)](Cl)(INT)${\cdot}$3H2O (2) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18 ,07.12 ]docosane, INT = isonicotinate) have been prepared and characterized by X-ray crystallography, electronic absorption, and cyclic voltammetry. The crystal structure of 1 reveals an axially elongated octahedral geometry with two axial isonicotinate ligands. The electronic spectra, magnetic moment, and redox potentials of 1 also show a high-spin octahedral geometry. However, 2 shows that the coordination environment around the copper atom is a distorted square-pyramid with an axial water molecule. The spectra and electrochemical behaviors of 2 are also discussed.

Chromospheric Canopy Fields over a Flux Emergence Region as a Key Condition for Formation of the Sunspot Penumbra

  • 임은경;;;조경석
    • 천문학회보
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    • 제38권1호
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    • pp.65.2-65.2
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    • 2013
  • A presence of a penumbra is one of the main properties of a mature sunspot, and its formation mechanism has been elusive due to a lack of observations that fully cover the formation process. Utilizing the New Solar Telescope at the Big Bear Solar Observatory, we observed the formation of a partial penumbra for about 7 hours simultaneously at the photospheric (TiO; $7057{\AA}$) and the chromospheric ($H{\alpha}$, $-1{\AA}$) spectral lines with high spatial and temporal resolution. From this uninterrupted, long observational sequence, we found that flux emergence under the stable chromospheric canopy fields resulted in penumbra formation, while emerging flux under the expanding chromospheric fields appeared as transient elongated granules. Based on these findings, we suggest a possible scenario for penumbra formation in which a penumbra forms when the emerging flux is constrained from continuing to emerge, but rather is trapped at the photospheric level by the overlying chromospheric canopy fields.

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실리콘과 카본을 이용한 다공질 탄화규소의 제조와 기계적 특성 (Fabrication and Mechanical Properties of Porous Silicon Carbide Ceramics from Silicon and Carbon Mixture)

  • 김종찬;이은주;김득중
    • 한국세라믹학회지
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    • 제50권6호
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    • pp.429-433
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    • 2013
  • Silicon, carbon, and B4C powders were used as raw materials for the fabrication of porous SiC. ${\beta}$-SiC was synthesized at $1500^{\circ}C$ in an Ar atmosphere from a silicon and carbon mixture. The synthesized powders were pressed into disk shapes and then heated at $2100^{\circ}C$. ${\beta}$-SiC particles transformed to ${\alpha}$-SiC at over $1900^{\circ}C$, and rapid grain growth of ${\alpha}$-SiC subsequently occurred and a porous structure with elongated plate-type grains was formed. The mechanism of this rapid grain growth is thought to be an evaporation-condensation reaction. The mechanical properties of the fabricated porous SiC were investigated and discussed.

Growth of Rubrene Crystalline Wire via Solvent-vapor Annealing

  • Park, Ji-Hoon;Choi, Jeong-M.;Lee, Kwang-H.;Mun, Sung-Jin;Ko, G.;Im, Seong-Il
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.871-873
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    • 2009
  • We report on the growth of rubrene ($C_{42}H_{28}$) wire fabricated by thermal evaporation, followed by solvent-vapor annealing for the application of organic thin film transistor. Solvent-vapor annealing was carried out in precisely controlled vapor pressure at elevated temperature. Micro-sized, and elongated rubrene wire was obtained via solvent annealing process reproducibly. Optical image and XRD data shows highly crystalline quality of rubrene wire.

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Polyethylene의 전기적,구조적 성질에 미치는 연신효 (Effect of Elongation on Electrical and Structral Properties of Polyethylene)

  • 박대희;김동욱;임기성;임기조;이동영;한민구
    • 대한전기학회논문지
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    • 제43권4호
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    • pp.601-606
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    • 1994
  • This paper describes the effect of elongation on electrical properties and molecular structrue of high density polyethylene. Thin polyethylene films films obtained dy roll elongation after extruded at 220$^{\circ}C$ and elongated to draw rations of 16. Crystallinity of polyethylene films was measured by X-Ray diffraction and electrical properties were estimated by conductivity and TSC(Thermal Simulated Current). It was foung that the crystallinity increases and the electrical conductivity decreases as the elongation increases. The elongation dependence of electrical conductivity may be explained by the trap density. Thus, the control of polymer structure and crystallinity makes its properties better and can be applicated in order to get more active properties.

An Analytical and Experimental Study of Binary Image Normalization for Scale Invariance with Zernike Moments

  • Kim, Whoi-Yul
    • Journal of Electrical Engineering and information Science
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    • 제2권6호
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    • pp.146-155
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    • 1997
  • In order to achieve scale- and rotation-invariance in recognizing unoccluded objects in binary images using Zernike moment features, an image of an object has often been normalized first by its zeroth-order moment (ZOM) or area. With elongated objects such as characters, a stroke width varies with the threshold value used, it becomes one or two pixels wider or thinner. The variations of the total area of the character becomes significant when the character is relatively thin with respect to its overall size, and the resulting normalized moment features are no longer reliable. This dilation/erosion effect is more severe when the object is not focused precisely. In this paper, we analyze the ZOM method and propose as a normalization method, the maximum enclosing circle (MEC) centered at the centroid of the character. We compare both the ZOM and MEC methods in their performance through various experiments.

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