• Applied Microscopy
• /
• 제47권4호
• /
• pp.226-232
• /
• 2017

Electron microscopy and X-ray diffraction have together played a key role in our understanding of the molecular structure and mechanism of contraction of muscle. This review highlights the role of electron microscopy, from early insights into thick and thin filament structure by negative staining, to studies of single myosin molecule structure, and finally to recent high-resolution structures by cryo-electron microscopy. Muscle filaments are designed for movement. Their labile structures thus present challenges to obtaining near-atomic detail, which are also discussed.

• 한국염색가공학회지
• /
• 제18권2호
• /
• pp.39-45
• /
• 2006

The aim of this work is to develop sense-differentiated textiles using Thick-Thin polyester yarn(T-T yarn) with finer than 1 denier mono filament. The ITY(Interlace Textured Yarn) using T-T yarn with various over feed ratios of PET filament was manufactured with different shrinking percentage of core yarn and then the fabrics were woven on the same weaving 100m using ITY produced. The mechanical properties and the handles of the fabrics were examined with KES-FB system suggested by Kawabata. The shrinkage of ITY was increased with decreasing over feed ratio and increased with increasing heat treatment temperature of T-T yarn. The initial elasticity modulus of ITY was decreased with increasing over feed ratio and heat treatment temperature of T-T yarn. The tensile energy of fabrics was decreased with increasing of over feed ratio, but bending rigidity and shear rigidity of fabrics were increased with increasing of over feed ratio of PET filament. The results indicate that the fabric using T-T yarn with finer than I denier mono filament can be used for the purpose of sense-differentiated textile.

• Entomological Research
• /
• 제48권5호
• /
• pp.429-438
• /
• 2018

Fine structural characteristics of the cardiac muscle and its sarcomere organization in the black widow spider, Latrodectus mactans were examined using transmission electron microscopy. The arrangement of cardiac muscle fibers was quite similar to that of skeletal muscle fibers, but they branched off at the ends and formed multiple connections with adjacent cells. Each cell contained multiple myofibrils and an extensive dyadic sarcotubular system consisting of sarcoplasmic reticulum and T-tubules. Thin and thick myofilaments were highly organized in regular repetitive arrays and formed contractile sarcomeres. Each repeating band unit of the sarcomere had three apparent striations, but the H-zone and M-lines were not prominent. Myofilaments were arranged into distinct sarcomeres defined by adjacent Z-lines with relatively short lengths of $2.0{\mu}m$ to $3.3{\mu}m$. Cross sections of the A-band showed hexagon-like arrangement of thick filaments, but the orbit of thin filaments around each thick filament was different from that seen in other vertebrates. Although each thick filament was surrounded by 12 thin filaments, the filament ratio of thin and thick myofilaments varied from 3:1 to 5:1 because thin filaments were shared by adjacent thick filaments.

• 한국염색가공학회지
• /
• 제18권3호
• /
• pp.42-48
• /
• 2006

The aim of this work is to develop Thick-Thin polyester yarn(T-T yarn) with finer than 1 denier mono filament. The manufacture of T-T yarns were carried out in a draw-winder using 85d/72f PET filament with various spinning speed of 2700, 2900, and 3100 m/min, respectively. The structure and physical properties of T-T yarns with spinning speed and over feed ratio were examined by draw-winder processing the sample in $100^{\circ}C$ water for 20 min and drying in 120, 140, 160, and $180^{\circ}C$ of dry air for 20 min. The crystallinity, the birefringence and the initial elasticity modulus of T-T yarns increased with increased spinning speed of filament and the heat treatment temperature but at the temperatures higher than $140^{\circ}C$ the increased rates show a tendency to decrease. Moreover, the initial modulus and the tenacity of T-T yarns increased with decreasing the over feed ratio of filament and the those of T-T yarns decreases with increasing the heat treatment temperature. The shrinkage of T-T yarns decreased with decreasing spinning speed and increased over feed ratio of filaments. Consequently, the results indicate that the best T-T yarn under 1 denier was optimized from PET filament with spinning speed of 2700 m/min and over feed ratio of 0.67

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2002년도 추계 수산관련학회 공동학술대회발표요지집
• /
• pp.118-119
• /
• 2002

근육이 수축하면 근원섬유의 sarcomere (근절)의 길이가 경직의 진행과 함께 짧아지는 것을 볼 수 있다. 즉, thick filament (myosin filament)와 thin filament (actin filament) 사이에서로 미끌어져 들어가는 현상이 일어나게 되는 것이다. 골격근은 보통 때는 이완상태에 있으나 필요할 때 신경자극에 의해서 수축을 하게 된다. 이러한 수축↔이완의 전환은 세포내의 $Ca^{2+}$ 농도의 조절을 통해서 제어되며, 이완시의 세포질 내의 $Ca^{2+}$ 농도는 정도의 낮은 상태로 유지된다. (중략)

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
• /
• pp.49-52
• /
• 2000

A new composite manufacturing technique which combines winding and curing together is studied and analyzed. This method is especially suited to the manufacture of thick composite materials in which thermal spiking is a common problem. An experimental apparatus was designed and built for use with a filament winder to continuously cure a thick composite cylinder. A hoop-wound composite cylinder with 152 mm wall thickness was manufactured and embedded thermocouples and strain gages were monitored throughout the cure process. The experimental data were compared with analytical results.

• 한국항공우주학회지
• /
• 제37권2호
• /
• pp.147-155
• /
• 2009

외부 수압을 받는 필라멘트 와인딩 후판 복합재 원통의 좌굴 및 파손을 유한요소법과 시험으로 연구하였다. 자체 개발 프로그램인 ACOS와 상업용 프로그램인 MSC.NASTRAN(선형)과 MSC.MARC(비선형)를 이용한 유한요소해석을 수행하였다. 복합재 원통 시편은 T700 카본-에폭시로 필라멘르 와인딩 기법에 의해 $[\pm30/90]_{FW}$, $[\pm45/90]_{FW}$, $[\pm60]_{FW}$, $[\pm60/90]_{FW}$의 각도로 제작하여 수압시험을 수행하였다. 사용한 세 가지 프로그램 중 ACOS가 시험값과 1.7~14.3%의 차이를 보이며 좌굴 압력을 가장 잘 예측하였다. 모든 경우에 좌굴 후 지지하중이 초기 좌굴하중보다 커지지 못하고 최종파손으로 연결되었다.

• 한국방사선학회논문지
• /
• 제15권2호
• /
• pp.101-108
• /
• 2021

CT는 인체 내 장기의 해부학적 구조를 정확하게 나타낼 수 있으며, 영상의 분해능이 우수하다. Brain CT 검사 시 수정체의 방사선 감수성이 높아서 피폭의 영향을 많이 받는다. 본 연구는 수정체에 피폭선량을 감소하기 위해 비스무스와 텅스텐 필라멘트 차폐물질을 사용하여 Non-shield와 Shield에 대한 피폭선량의 변화와 차폐율을 비교 하고자 한다. 본 연구에서는 3D printing으로 제작한 비스무스, 텅스텐 필라멘트 차폐물질을 사용하여, 차폐물질 두께와 slice에 따라 피폭되는 선량을 측정하였다. 헤드팬텀을 고정시켜 안구에 Magicmax universal 선량계를 위치시켜 차폐 물질을 놓지 않았을 경우와 그 위에 차폐 물질을 놓았을 때 차폐율을 각각 비교하기 위해 두 물질을 1mm ~ 5mm 두께로 각각 측정하였다. 1 mm 두께의 필라멘트에서 비스무스 필라멘트는 26.8 %, 텅스텐 필라멘트는 43.1 % 차폐율이 나타났다. 따라서 비스무스 필라멘트보다 텅스텐 필라멘트에서 더 큰 차폐효과가 나타났다. 차폐체의 종류, 두께, 슬라이스 간격에 따라 선량을 측정한 결과, 비스무스 필라멘트 보다 텅스텐 필라멘트가 더 큰 차폐효과가 나타났다.

• 마이크로전자및패키징학회지
• /
• 제28권4호
• /
• pp.41-45
• /
• 2021

본 연구에서는 멤리스터 소자의 높은 신뢰성을 확보하기 위해 소자 제작 단계에서 30 nm 두께의 ZrO₂ 금속산화물 박막 위 국부영역에 리튬 filament seed 층을 패턴하여 작은 이온반경의 리튬이온을 저항변화 주체로 활용하는 멤리스터 소자를 구현하였다. 패턴 된 리튬 filament seed 대비 다양한 상부전극의 면적을 적용하여 멤리스터-커패시턴스 병렬 구조의 이온형 저항변화 소자에서 커패시턴스가 filament type 저항변화 특성에 미치는 영향을 조사하고자 하였다. 이를 위해 ZrO₂ 박막 위에 5 nm 두께, 5 ㎛ × 5 ㎛ 면적의 리튬 filament seed 증착 후 50 ㎛, 100 ㎛ 직경의 상부전극을 증착, 리튬 메탈의 확산을 위한 250℃ 열처리 전 후 샘플에서 저항변화 특성을 확인하였다. 열확산에 의해 형성된 전도성 filament의 경우 전압에 의한 제어가 불가함을 확인하였으며, 전압에 의해 형성된 filament만이 electrochemical migration에 의한 가역적 저항변화 특성 구현이 가능한 것을 확인하였다. 전압에 의한 filament 형성 시 병렬로 존재하는 커패시턴스의 크기가 filament의 형성 및 소실에 중요한 인자임을 확인하였다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제43권6호
• /
• pp.453-460
• /
• 2020

The price of the Brain phantom (Hoffman 3D brain phantom) used in nuclear medicine is quite expensive, it is difficult to be purchased by a medical institution or an educational institution. Therefore, the purpose of present research is to produce a low-price 3D brain phantom and evaluate its usefulness by using a 3D printer capable of producing 3D structures. The New 3D brain phantom consisted of 36 slices 0.7 mm thick and 58 slices 1.5 mm thick. A 0.7 mm thick slice was placed between 1. 5 mm thick slices to produce a composite slice. ROI was set at the gray matter and white matter scanned with CT to measure and compare the HU, in order to verify the similarity between PLA which was used as the material for the New 3D brain phantom and acrylic which was used as the material for Hoffman 3D brain phantom. As a result of measuring the volume of each Phantom, the error rate was 3.2% and there was no difference in the signal intensity in five areas. However, there was a significant difference in the average values of HU which was measured at the gray and white matter to verify the similarity between PLA and acrylic. By reproducing the previous Hoffman 3D brain phantom with a 100 times less cost, I hope this research could contribute to be used as the fundamental data in the areas of 3D printer, nuclear medicine and molecular imaging and to increasing the distribution rate of 3D brain phantom.