• Applied Microscopy
• /
• 제24권4호
• /
• pp.115-122
• /
• 1994

A computer program has been developed to analyze easily the Kikuchi pattern which is useful in obtaining the crystallographic data of materials. This program can simulate the Kikuchi patterns for 14 Bravais lattice by using the matrix algebra. Convenient menu system was also added to enhance the applications of the program. That is, by varying the tilting angle, camera length (RADIUS) and $S_{max}$ in the menu, various Kikuchi patterns can be obtained. The simulated patterns, then, can be compared with the experimentally-obtained Kikuchi pattern to examine validity of simulation.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1997년도 춘계학술발표회논문집(2)
• /
• pp.189-194
• /
• 1997

니켈기 전열관 소재에서 결정립계의 misorientation을 분석하였다. 일반적으로 대부분의 결정립계에서 석출물을 관찰 할 수 있지만 쌍정과 만나게 되면서 석출물의 분포가 갑작스럽게 변하는 것을 관찰 할 수 있다. 이러한 현상은 결정립계의 구조와 에너지에 관련되는 결정립계의 misorientation 특성에 갑작스런 변화가 생겨나기 때문이라. 이러한 결정립계의 misorientation 특성은 T.E.M (Transmission Electro Microscope)에서 얻은 각 결정립의 Kikuchi pattern을 이용하여 분석하었다. 석출물을 갖는 결정립계들은 random high angle 결정립계이고 석출물이 존재하지않는 결정립계들은 특정한 C.S.L ( Coincidence Site Lattice) 결정립계이었다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.942-944
• /
• 2009

Blue phase shows several different reflection colors from the randomly oriented domains and crystal direction. Also there are variations in the size of domains. The domain size is dependent on the temperature gradient. With smaller cooling rate of temperature, the domain size was increased compared with rapid cooling. With injection of light of specific wavelength, we find that the diffraction patterns were occurred around the light spot in the cell of blue phase. It was supposed to be from the matching of the phase retardation and domain size. However, actually the diffraction pattern is reflecting the lattice structure in double twist of the blue phase. The lattice constant from the radius of diffraction patterns shows very similar one from the reflection spectrum, which indicates the internal lattice constant in double twist of the blues phase.

• Applied Microscopy
• /
• 제33권3호
• /
• pp.179-185
• /
• 2003

일반적으로 전자현미경에 계기상 나타내는 가속전압에 의한 전자 빔의 파장은 실재로 시료 위에 입사되는 빔의 파장 값과는 다를 수 있다. 그러므로 적어도 한번은 계기상 나타난 전압에 대한 파장 값을 측정할 필요가 있다. 특히 QCBED 기법에서는 가능한 한 정확한 파장 값의 결정이 요구된다. 본 논문에서는 알려진 결정시료의 LACBED 패턴들로부터 정확하게 이 파장을 측정하는 간단한 방법을 제시한다. 이 방법은 이미 보고된 Kikuchi 패턴을 이용하는 기법과 유사하게 LACBED 패턴에서 같은 평면에 있지 않은 3개의 회절벡터에 의한 회절선이 거의 같은 점을 교차할 경우를 이용한다. 이 방법 적용 실험 예로써 알루미늄 결정시료를 사용하여 JEM2010전자현미경의 계기상 200 kv 가속전압에 대한 파장 값이 측정되었다. 측정된 파장과 대응되는 가속전압은 0.002496(3) nm과 $201.5{\pm}0.4$ kv이며 파장 값은 0.12%의 불확실성을 갖고 있다.

• Wind and Structures
• /
• 제3권4호
• /
• pp.279-289
• /
• 2000

The main purpose of this paper is to demonstrate the necessity of considering wind load combinations even for low-rise buildings. It first discusses the overall quasi-static wind load effects and their combinations to be considered in structural design of low-rise buildings. It was found that the maximum torsional moment closely correlates with the maximum along-wind base shear. It was also found that the instantaneous pressure distribution causing the maximum along-wind base shear was quite similar to that causing the maximum torsional moment, and that this asymmetric pressure pattern simultaneously accompanies considerable across-wind and torsional components. Secondly, the actual wind pressure distributions causing maximum quasi-static internal forces in the structural frames are conditionally sampled and their typical pressure patterns are presented.

• 생태와환경
• /
• 제38권4호통권114호
• /
• pp.435-438
• /
• 2005

We observed the physical, chemical, and biological characteristics of an acidic lake, Lake Katanuma, from 1998 to 2002 at weekly or biweekly intervals, except during the winter. This volcanic lake has a dimictic thermal pattern. In summer, the volcanic heat supply at the lake bottom results in weak thermal stratification. In 1998, 1999, and 2002, short-term holomixis was observed during the stratification period, when the anoxic, hydrogen sulfide-rich water from the hypolimnion spread across the entire lake. In contrast, distinct short-term holomixis did not occur during the stratificatlon period in 2000 and 2001. However, the early onset of the autumn turnover in August 2000 and 2001 caused anoxic conditions to persist throughout the entire water column for more than 2 weeks. The anoxic and hydrogen sulfide-rich conditions affected population densities of chironomid larvae (Chironomus acerbiphilus) and planktonic algae (Chlamydomonas acidophila), both dominant species in Lake Katanuma. Thus, the interannual variations of limnological characteristics influenced the seasonal population changes of these species.

• 폴리머
• /
• 제29권3호
• /
• pp.294-299
• /
• 2005

온도응답성 고분자인 PIPAAm을 포토마스크를 사용하여 전자빔조사에 의해 패턴상으로 세포배양용 폴리스티렌 접시표면에 그래프트하였다. 폴리스티렌 표면에의 PIPAAm의 그래프트는 AIR-FTIR과 ESCA에 의한 표면분석을 통해 확인하였다. 이러한 표면에 간실질세포를 $37^{circ}C$에서 배양하였고, 균일하게 간세포가 배양된 배양접시를 PIPAAm의 LCST 이하인 $20^{circ}C$로 배양온도를 낮추어 PIPAAm이 그래프트된 도메인에 접착된 간실질세포를 탈착시키고 배양접시를 다시 $37^{circ}C$로 올린 후 두 번째 세포인 혈관내피세포를 파종하여 PIPAAm이 그래프트된 도메인에만 선택적으로 접착시킴으로써 같은 평면상에서 간실질세포와 혈관내피세포를 공배양할 수 있게 되었다. 이러한 방법으로 생체외에서 간실질세포와 혈관내피세포를 장기간에 걸쳐 공배양할 수 있었다.

• ALGAE
• /
• 제23권4호
• /
• pp.277-288
• /
• 2008

The relationship between nutrients and phytoplankton dynamics was investigated daily from 12 April to 22 July 2003 in Sagami Bay, Japan. According to multidimensional scaling (MDS) and cluster analysis, phytoplankton community was divided into four distinct groups. The first group was consisted of centric diatom species, such as Guinardia spp., Detonula spp., Letocylindrus danicus, Skeletonema costatum, Eucampia zodiacus and Chaetoceros spp.. The second and third clusters comprised mainly diatoms and dinoflagellates, respectively. The other cluster was restricted to the samples collected during the last sampling period when the rainfall and river discharge was frequently recorded. Canonical correspondence analysis (CCA) was applied to analyze four groups respectively, which focused on the effects of nutrients concentration and ratio on phytoplankton variations. Based on CCA analysis, most species of centric diatom were negatively correlated with DSi concentrations and Si/N ratio. Nutrients were strongly limited phytoplankton growth during the summer when the rainfall was not observed, whereas river discharge by rainfall and counterclockwise coastal currents (although the surface circulation pattern is often altered by Kuroshio Current, the counterclockwise coastal currents are generally dominant) has brought phytoplankton population accumulation and triggered the micoalgae growth in western part of the bay. Phosphorous (P) was strongly limited after significantly increases in the phytoplankton abundances. However, silicate (Si) was not a major limiting factor for phytoplankton production, since Si/DIN and Si/P ratio did not create any potential stoichiometric limitation. This indicates that high Si availability contributes favorably to the maintenance of diatom ecosystems in Sagami Bay.