• 한국안전학회지
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• 제34권2호
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• pp.7-14
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• 2019

A palladium can adsorb hydrogen and detect leaking hydrogen through changes in color and electrical resistance. This study is to evaluate the structural behavior of carbon fiber adding palladium composite materials used in the hydrogen storage vessel. A multi-scale analysis technique was used to analyze accurately the behavior of each material in relation to the microscopic composition. The multi-scale analysis is more proper and precise for composite materials because of considering the individual microscopic structure and properties of each material for composite materials. Also the crack evaluation was performed by XFEM analysis to confirm the reinforcement performance of aluminum as a liner of the hydrogen vessel. The results show that the addition of the palladium material increased the macroscopic stress, but microscopically the carbon fiber stress was reduced. It means the performance improvement of the palladium added carbon fiber/Al composite.

• 한국미생물·생명공학회지
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• 제5권3호
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• pp.133-140
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• 1977

Nocardia sp의 세포내 징세포구조 및 tellurite 환원초소의 존재부위와 T. T. C. 환원부위를 전자현미경으로 관찰한 것을 요약하면 다음과 같다. 광포내 미세구조에 있어서 unit membrane을 가진 농양구조가 복잡한 형태를 하고 계포질에 내포되어있고 어떤 것은 막구조가 둥글게 감겨있는 형태도 있다. 금속, tellurate염외 석출이 세포질중에 나타나므로 tellurite 및 tellurate 환원효소는 세축질중에 존재한다는 것을 알 수 있다. 그리고T.T.C.의 환원은 세포막 및 세포내막양구조 부분에서 일어난다. 따라서 tellurate환원과 T.T.C.환원은 서로 상이한 부위에서 일어남을 알 수 있다. 구체내에 형성된 T.T.C. tellurate은 도정제인 osmic acid에 의하여 제기화되며, 더우기 탈수제로 사용하고 있는 ethanol에 녹고 아울러 포매각에도 녹기 때문에 약 95％의 formazane이 균체외로 용출되어 나오므로 검정시의 세포내에는 거의 formazane이 존재하지 않기 때문에 전자현미경상의 전자투과성인 부분은 원래 formazane이 형성되었던 부분인 것이다.

• Applied Microscopy
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• 제36권3호
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• pp.209-216
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• 2006

투과전자현미경을 이용한 3차원적 구조분석의 신뢰도를 향상시키기 위해서는 고니오미터와 사용되는 시료 홀더에 대한 정확도와 정밀도의 측정 및 보정이 필요하다. 본 연구에서는 상업용 투과전자현미경 홀더 중의 하나인 rotation holder에 대한 작동원리를 기술하고 회전각의 정확도를 측정하였다. 투과전자현미경 내부에서 회전된 이미지의 분석을 통한 홀더의 회전각의 측정오차는 ${\pm}0.42^{\circ}$이었다. 회전각의 정확도를 비교하기 위해 투과전자 현미경 외부에서 시료 홀더에 부착된 반사경에 레이저 빔을 반사시켜 측정한 결과, 회전각의 측정오차는 ${\pm}0.6^{\circ}$이었다. 추가적으로 시료컵과 회전벨트 사이의 불안정한 맞물림에 의해 야기된 비정상적인 시료의 회전경로에 대해서도 점검하였다.

• 한국광학회지
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• 제14권6호
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• pp.613-622
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• 2003

반도체 와이어 본딩(wire-bonding) 조립공정에 사용되는 검사용 다중배치 현미경 광학계를 설계하였다. 2배와 6배에 공통으로 사용되는 대물부를 통과한 광선은 광분할 프리즘으로 둘로 나뉘고 각각의 결상부에 의하여 물체의 주변부는 2배, 물체의 중심부는 6배로 결상하게 한다. 이 때 리드프레임의 와이어 구조 때문에 $\pm$3 mm의 높이차가 있어서 대물부에서 물체까지의 거리가 서로 다르다. 이러한 단차에 ,의해 물체거리가 바뀌더라도 동일한 결상 배율로 선명하게 관찰하기 위해 결상부를 기계 보정식 줌 렌즈와 같이 비선형 궤적으로 이동시켜야 한다. 이 궤적을 구하기 위해 가우스 괄호를 사용해 비선형 연립방정식을 세우고 풀었다. 또한 각 렌즈 군의 굴절능과 군간 간격을 구하는 군별 기초 설계는 등가렌즈에 대한 3차 수차 이론을 사용하였으며, 최종적으로 최적화 기법을 통하여 이러한 현미경 광학계를 얻었다.

• Applied Microscopy
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• 제39권4호
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• pp.341-348
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• 2009

본 연구에서는 평균 입자크기가 100 nm인 $BaTiO_3$ 나노 결정체의 결정 구조를 전자회절을 이용하여 분석하였다. 전자회절을 이용하여 구조분석을 수행하기 위해 PED 장치의 실험인자를 보정한 후, PED와 일반적인 SAED를 이용하여 전자회절도형을 획득하여 비교 분석을 수행하였다. $BaTiO_3$ 나노 결정체에 대해 PED를 이용한 구조분석을 수행한 결과, $BaTiO_3$ 나노입자는 상온에서 입방정계와 정방정계의 구조가 혼합되어 존재함을 알 수 있었다. 또한 이론적 계산을 통해 두 상이 혼재된 $BaTiO_3$ 나노입자는 입방정계의 구조가 약 8.5nm의 표면을 형성하고 있는 coreshell 구조를 이루고 있음을 예측할 수 있었다. 이러한 $BaTiO_3$ 나노입자에 대한 입방정계와 정방정계 구조의 각각의 격자상수는 a=3.999${\AA}$과 a=3.999${\AA}$, c=4.022${\AA}$이었다. 이와 같이 일반적인 SAED에 비해 뛰어난 공간분해능과 다중산란 효과를 억제할 수 있는 PED 기법은 복합 나노 구조체의 결정구조분석에 보다 유용한 분석 기술로 활용할 수 있을 것으로 기대된다.

• 한국식품조리과학회지
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• 제1권1호
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• pp.57-64
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• 1985

This study was conducted to investigate the effect of fat on structure and texture of soybean curds by partial or whole replacement of soybean with defatted soy flour, The textural properties of soybean curd were examined by Instron universal testing machine, and the microscopic structure of soybean curds was examined by Scanning electron microscope(SEM). The results obtained were as follows ; 1. Textural parameters determined by Instron universal testing machine showed that hardness and gumminess of soybean curs were significantly increased as the fat contents of the samples decreased. On the while, springiness of the samples were significantly lowered as the fat content decreased. 2. Microscopic structure of soybean curds examined by SME demonstrated that samples with high fat had more fat globules and thinner network layer which were assumed to surround moisture with.

• 한국공작기계학회논문집
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• 제10권6호
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• pp.42-47
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• 2001

In this study, fatigue limit of ductile cast iron is evaluated based on phenomena of the microscopic observation, such as matrix structure, spheroidal ratio, size of graphite and distribution. Three different ferrite-pearlite matrix structure, GCD 45-), GCD 50, GCD 60 series, all of which contain more than 70% spheroidal ratio of graphite, were used to obtain the correlation between maximum size of graphite and fatigue strength. It was concluded as fellows. (1) In Ductile cast iron of ferrite-pearlite matrix, the fatigue limit of GCD 60 series with 73% pearlite structure was the highest. (2) From observation of the starting point of crack of all specimens, it is noted that the crack initiates, in graphite, goes through ferrite and propagates into pearlite. (3) A good quality of Ductile cast iron used in this experiment can be checked from uniformly distributed graphite. The negligible interaction effect between graphites was verified by microscopic observation and fracture mechanics investigation in surface and interior of the specimen.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.497-500
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• 2004

Recently, the use of structure compound waterproof agent (hereinafter referred to as 'SCWA') that is used when manufacturing concrete for concrete structures, increases in quantity. However, while it is expected that the SCWA that is mixed in the concrete inside can significantly affect the change of physical properties that lift the internal force of a structure. This study has been conducted through an experiment for the effects of cement hardener on the formation of microscopic texture, and newly generated hydrates from that result were not confirmed in the present experiment. It was found that at the hydrate reaction it has the property that can be hardened within the limit of pore diameterar a specific size rather than there is the internal gap filling capacity due to generating other hydrates.

• Applied Microscopy
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• 제52권
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• pp.6.1-6.5
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• 2022

We examined the morphology of the fertilized egg and the fine structure of fertilized egg envelopes of Poropanchax normani belonging to the family Poeciliidae, also known as Norman's lampeye using light and electron microscopes. The fertilized eggs with narrow perivitelline space were found to be spherical and demersal, additionally containing small oil droplets in the vitelline membrane. Further, a bundle of adhesive filaments was observed to be present on one side of the fertilized egg. These filaments possessed remarkably high elasticity and were approximately 1-3mm in length. The size of the fertilized egg was determined to be about 1.49 ± 0.07mm (n=30). The outer surface appeared smooth, and adhesive filaments originating at different location of the surface of the envelope were found to be distributed around the egg envelope and were joined together to form a single long bundle in scanning electron microscopic observation. A peak-like structure formed of several straight wrinkles was observed around the micropyle. However, the complete structure of the micropyle could not be studied due to the depth at which it was located. Additionally, the total thickness of the egg envelope was ascertained to be approximately12.5-14.5㎛. The egg envelope consisted of two distinct layers, an outer electron dense layer and an inner lamellar layer, further consisting of 10 sublayers of varying thicknesses. Collectively, it was observed that the morphological characteristics of the fertilized egg, fine structures surrounding the micropyle, outer surface, adhesive structure consisting adhesive filaments, and sections of fertilized egg envelope displayed species specificity.

• Applied Microscopy
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• 제44권4호
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• pp.138-143
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• 2014

Transmission electron microscope (TEM) is an excellent tool for studying the structure and properties of nanostructured materials. As the development of $C_s$-corrected TEM, the direct analysis of atomic structures of nanostructured materials can be performed in the high-resolution transmission electron microscopy (HRTEM). Especially, fast Fourier transform (FFT) technique in image processing is very useful way to determine the crystal structure of HRTEM images in reciprocal space. To apply FFT technique in HRTEM analysis in more reasonable and friendly manner, we made a new circular region of interest (C-ROI) FFT script and tested it for several HRTEM analysis. Consequentially, it was proved that the new FFT application shows more quantitative and clearer results than conventional FFT script by removing the streaky artifacts in FFT pattern images. Finally, it is expected that the new FFT script gives great advantages for quantitative interpretation of HRTEM images of many nanostructured materials.