Morphological features of a hybrid between a Hill Pigeon and a Feral Pigeon at the early stage of interspecific hybridization

강승구,이선주,윤준희,김진용,권인기,박민지,윤종민 한국조류학회II 2022 한국조류학회지 Vol.29 No.2

This study provides evidence of interspecific hybridization between a female Hill Pigeon (Columba rupestris) and a male Feral Pigeon (C. livia var. domestica), producing offspring at the Hwaeomsa Temple in Gurye County, South Korea. Under the Hill Pigeon Recovery Plan (2021–2027) established by the Korean Ministry of Environment, we field-surveyed the colonial breeding habitat, captured the interspecifically hybridized family, and transferred it to captivity for further investigation in 2021. Each parent exhibited species-specific characteristics of the Hill and Feral Pigeons. The overall appearance and size of the hybrid offspring were similar to those of the female parent, but the absence of a white-banded tail followed the trait of the male parent. Our findings may provide fundamental information for future morphological and genetic studies of the interspecific hybridization of these two species.

관광과 물류의 중요성

강승구 한국지역사회연구소 2004 지역사회 Vol.49 No.-

제 2 발표장 : 투명한 방탄 복합재료의 제조 및 특성

강승구 한국복합재료학회 1993 한국복합재료학회 학술발표회 논문초록집 Vol.- No.2

종결정법을 이용한 저전압 ZnO 배리스터의 제조 및 전기적 특성

강승구,오재희 한국세라믹학회 1988 한국세라믹학회지 Vol.25 No.5

ZnO low voltage varistor was obtained by varying a) the amount of seed grains, b) the size of seed grains, and c) sintering temperature. Also, the optimum condition for fabricating the ZnO seed grains was studied. Large ZnO seed grains were obtained by washing a ZnO sintered body containing 1m/of BaCO3 in boiling water. When the seed grains were added, abnormal grain growth occurred, and the varistor voltage sharply decreased. However, when more than 5w/o of seed grain content was added, the varistor voltage gradually increased. When 10w/o seed grains of 75~106${\mu}{\textrm}{m}$ were added and sintered for 2 hours at 1200 to 125$0^{\circ}C$, low voltage varistor properties with V1mA/mm of 19V/mm and nonlinear exponent ($\alpha$) of 12 occurred.

수부습진

강승구,김재홍 한국의학사 1996 診斷과治療 Vol.16 No.7

Sol-Gel법을 이용한 광학재료의 제조

강승구 경기대학교 부설 산업기술종합연구소 1997 산업기술종합연구소 논문집 Vol.13 No.-

sol-gel 화학반응에서 금속알콕사이드의 수화와 축합은 매우 중요하다. 광학재료를 sol-gel법으로 합성할때 투명도, 제어된 기공율등의 특수성질이 요구된다. 금속알콕사이드를 nucleophilic species에 의해 변화를 주면 고분자화반응을 화학적으로 제어할 수 있다. 더구나 비수화성 유기기가 금속전구체에 결합되면 유기-무기 혼성재료가 만들어질 수 있다. 이러한 혼성체를 ORMOCERs라고 하며 최근 졸겔 광학분야에서 비다공성 투명 재료로 쓰이고 있다. 한편 기판위에 sol용액을 코팅하여 박막형 광학재료를 제조하는 경우 코팅환경, sol의 점도, 용매, 용질들의 특성 등이 엄격히 제어되어야 한다. The hydrolysis and condensation chemistry reaction is very essential in sol-gel processing of metal alkoxides. Requirments for the optical materials using by sol-gel method are the transparency, controlled porosity etc.. The polymerization process can be controlled chemically by the variation of metal alkoxides using the nucleophilic species. Furthermore hybrid organic-inorganic materials can be obtained when non hydrolyzable organic ligands are bonded to the metal precursor. Such hybrid, known as ORMOCERs, are now currently used as non porous transparent matrics for sol-gel optics. The sol-gel process has proved to be an excellent method for the preparation of many types of optical coatings. Cleaness is essential in coating process and this is applied to all aspects, particularly to the coating liquid, environment and substrate.

다양한 성형법으로 제조된 인공 골재의 특성

강승구,Kang, Seung-Gu 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.1

The physical properties of artificial aggregates made from clay and inorganic wastes with poor plasticity depends largely on forming method. The artificial aggregates composing of coal fly ash, stone sludge and clay were fabricated using 4 different forming methods and those physical properties were comparatively analyzed. The surface of aggregates made through the extrusion forming process was dense and smooth but was rough for the aggregates obtained by crushing a tile-shaped green body. The aggregates made by pelletizing process had a weak green strength and bumpy surface. The shell generated at surface during a high temperature sintering process induced the most aggregates to be bloated due to a dense shell. But the aggregates made through pelletizing process with dense surface layer showed no significant change in bulk density with sintering temperatures. The water absorption of aggregates decreased with sintering temperature, and that of pelletized specimen was standing $1.8{\sim}2.2$ times higher than that of made by other forming methods. It is concluded that the aggregates having various properties could be fabricated from one batch by using different forming methods.

인공경량골재의 표피층 구조가 흡수된 물의 방출속도에 미치는 영향

강승구,Kang, Seung-Gu 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.11

The artificial aggregates with dense surface layer (shell) was fabricated and the dependence of water emission rate upon the shell structures was studied. The EAF dust containing many flux components and waste white clay with ignition loss of above 48% were used as for liquid phase and gas forming agents during a sintering process respectively. In addition, the shell structure was modified with various processes and the modification effect on water emission rate was analyzed. The pores under $10{\mu}m$ were found in the sintered artificial light aggregates and disappeared by incorporating to a bigger pore during re-sintering. The water emission rate in an initial step depended on a void content of aggregates filled in a bottle rather than a shell structure. But, after 7 days where the water emission of the aggregate with a shell is above 40%, the shell of aggregates suppressed the water emission. The core of aggregates was exposed and most shell was lost when crushed to smaller size so, the ability for suppressing water emission of the crushed aggregates decreased. The activation energy for the water emission was $3.46{\pm}0.25{\times}10^{-1}$J/mol for the most specimens showing that the activation energy is irrelevant to the pore size distribution and shell structure.

화력발전소 바닥재로 제조된 결정화 유리의 미세구조

강승구,Kang, Seung-Gu 한국재료학회 2009 한국재료학회지 Vol.19 No.2

Glass ceramics were made from coal bottom ash by adding CaO and $Li_2O$ as glass modifiers and $TiO_2$ as a nucleating agent in a process of melting and quenching followed by a thermal treatment. The surface of the glass ceramics has 1.6 times more $Li_2O$ compared to the inner matrix. When $TiO_2$ was not added or when only 2 wt% was added, the surface parts of the glass ceramics were crystalline with a thickness close to $130{\mu}m$. In addition, the matrixes showed only the glass phase and not the crystalline phase. However, doping of $TiO_2$ from 4 wt% to 10 wt% began to create small crystalline phases in the matrix with an increase in the quantity of the crystalline. The matrix microstructure of glass ceramics containing $TiO_2$ in excess of 8 wt% was a mixture of dark-gray crystalline and white crystalline parts. These two parts had no considerable difference in terms of composition. It was thought that the crystallization mechanism affects the crystal growth, direction and shape and rather than the existence of two types of crystals.

졸-겔법에 의한 (Yb_xY_1-x)MnO₃강유전체 박막제조

강승구,이기호 한국세라믹학회 2004 한국세라믹학회지 Vol.41 No.2

Y-acetate, Yb-acetate와 Mn-acetate를 출발물질로 사용하여 sol-gel 법으로 강유전성 (Y $b_{x}$ $Y_{1-x}$)Mn $O_3$ 박막을 제조하였다. Acetylaceton을 촉매로 사용하고 Reflux 법을 이용하여 안정한 (Y $b_{x}$ $Y_{1-x}$)Mn $O_3$ 전구체 용액을 얻었으며, 박막은 스핀 코팅방법으로 Si(100) 기판 위에 제조하였다 열처리 온도, 코팅용액의 Rw($H_2O$/alkoxide moi ratio)변화 등을 실험변수로 하여 박막의 결정상 변화를 연구하였다. X-선 회절분석 결과 YbMn $O_3$의 결정상을 얻기 위한 최저 열처리온도는 7$50^{\circ}C$이었으며, 최적 열처리 조건은 80$0^{\circ}C$였다 Rw를 1∼6 범위 내에서 조절하여 첨가한 결과, Rw=1의 조건에서 c-축 배향이 잘 발달된 hexagonal YbMn $O_3$ 단일 결정상을 얻었다. Si(100)기판 위에 제조된 (Y $b_{x}$ $Y_{1-x}$)Mn $O_3$ 박막은 x=0 또는 1인 경우 잔류분극(Pr)값이 약 200 nC/$ extrm{cm}^2$을 나타내었으나 0<x<1 범위인 경우 Pr값이 200 이하로 나타났다. The ferroelectric (Y $b_{x}$ $Y_{1-x}$)Mn $O_3$ thin films were fabricated by sol-gel method using Y-acetate, Yb-acetate, and Mn-acetate as raw materials. The stable (Y $b_{x}$ $Y_{1-x}$)Mn $O_3$ precursor solution (sol) was prepared through the reflux process with acetylaceton as a catalyst and coated on Si(100) substrate by spin coating. The heat treatment temperature and, Rw ($H_2O$/alkoxide moi ratio) dependence on crystallinity of thin films were studied. The lowest temperature for obtaining YbMn $O_3$phase and the optimum heat-treatment conditions were proved as at 7$50^{\circ}C$ and 80$0^{\circ}C$, respectively. The hexagonal YbMn $O_3$with c-axis preferred orientation could be obtained at Rw=1 condition. The remanent polarization for the thin films of x=0 or 1 was about 200 nC/㎤ while, for the specimens ot 0< x< 1, were 50∼100 nC/$\textrm{cm}^2$.