A5101419349- Carbon Nanotubes in Composites
- Graphene research and applications
- High-Velocity Impact and Material Behavior
- Polymer Nanocomposite Synthesis and Irradiation
- Fatigue and fracture mechanics
- Diamond and Carbon-based Materials Research
- Carbon and Quantum Dots Applications
- Graphene and Nanomaterials Applications
- Anodic Oxide Films and Nanostructures
- Radiation Detection and Scintillator Technologies
- Structural Response to Dynamic Loads
- Advanced Electron Microscopy Techniques and Applications
- Radiation Effects in Electronics
- Advanced Radiotherapy Techniques
- Surface Modification and Superhydrophobicity
- Radiation Therapy and Dosimetry
- Advancements in Solid Oxide Fuel Cells
- Thermal properties of materials
- Synthesis and properties of polymers
- Organic Electronics and Photovoltaics
- Chemical and Physical Properties of Materials
- Automotive and Human Injury Biomechanics
- Mechanical Behavior of Composites
- Advanced X-ray Imaging Techniques
- Cellular and Composite Structures
Korea Atomic Energy Research Institute
2020-2024
Government of the Republic of Korea
2016-2020
Korea Advanced Institute of Science and Technology
2011-2017
Pohang Iron and Steel (South Korea)
2014-2016
Daejeon University
2016
Abstract A vacuum-sealed miniature X-ray tube based on a carbon nanotube field-emission electron source has been demonstrated. The diameter of the is 10 mm; total length 50 mm, and no external vacuum pump required for operation. maximum voltage reaches up to 70 kV, generates intense X-rays with air kerma strength 108 Gy·cm 2 min −1 . In addition, produced from have comparatively uniform spatial dose distribution.
The effects of electron-beam irradiation on the organic semiconductor rubrene and its application as a dosimeter was investigated. Through measurements photoluminescence ultraviolet photoelectron spectroscopy, we found that induces n-doping rubrene. Additionally, fabricated thin-film transistors with pristine irradiated rubrene, discovered decrease in transistor properties originated from threshold voltages are shifted to opposite directions layers. Finally, highly sensitive air-stable...
Polyimide is commonly used as a substrate for flexible electronic devices because of its excellent thermal, physical, and electrical properties. To enhance the adhesion between substrates electrodes, it necessary to improve hydrophilic properties polyimide. Various surface treatments, such plasma treatment, laser ablation, ultraviolet have been applied this purpose. In study, we demonstrated that Cu Ti ion beam irradiation can temporarily create superhydrophilic on polyimide after...
Silicon (Si) nanostructures that exhibit a significantly low reflectance in ultraviolet (UV) and visible light wavelength regions are fabricated using hydrogen etching process. The Si have aperiodic subwavelength structures with pyramid-like morphologies. detailed morphologies of the can be controlled by changing condition. nanostructured exhibited much more reduced than flat surface: an average was approximately 6.8% region slight high 17% UV region. further both through deposition...
Carbon nanotube (CNT) field emitters that exhibit extremely high stability against high-voltage arcing have been demonstrated. The CNT were fabricated on a sharp copper tip substrate produces electric field. A metal mixture composed of silver, copper, and indium micro- nanoparticles was used as binder to attach CNTs the substrate. Due strong adhesion mixture, not detached from even after many intense events. Through electrical conditioning as-prepared emitters, vertically standing with...
Graphene can be synthesized from polyacrylonitrile (PAN) polymer through pyrolysis. A metal catalyst such as nickel (Ni) is required for the conversion of to graphene. The catalysts placed either atop or underneath precursor. We observed that spatially non-uniform and disconnected graphene was fabricated when PAN film coated with a Ni layer pyrolyzed, resulting in flake-like Formation attributed dewetting on film. Dewetting phenomenon reduced by decreasing pyrolysis temperature, hence, more...
Small tip‐type CNT emitters with the diameter of 0.8 mm were fabricated for miniaturized X‐ray tubes. The prepared by dropping CNTs and silver nanoparticles on a flat surface W metal tip followed annealing at 800°C 2 h under vacuum. exhibit good field emission properties threshold electric 1.15 V/ μ m enhancement factor 12,050. well attached to without coating side plane tip, thus beam divergence could be minimized. Consequently, tube inner 5 was successfully demonstrated using emitter.
We have presented a mechanism to explain why the resulting oxide morphology becomes porous or tubular nanostructure when zircaloy is electrochemically anodized.A zirconium always formed at an initial anodization stage, but degree of interpore dissolution determines whether final nanoporous nanotubular.The rate can be tuned by changing parameters such as time and water content in electrolyte.Consequently, nanostructures selectively fabricated on surface controlling parameters.Based this...
We present the first work of synthesis mechanism from graphene quantum dots (GQDs) to carbon nanotubes (CNTs) by an ion-sputtering assisted chemical vapor deposition. During annealing process, a Pt thin film deposited was dewetted and agglomerated form many nanometer-sized particles, leading nanoparticles (PtNPs) that can act as catalysts for creating allotropes. The shape allotropes be effectively tailored GQDs CNTs controlling three key parameters such dose catalytic ions (D), amounts...
H<sup>+</sup> irradiation increases the surface hardness of polycarbonate.
A simple route to freestanding graphene nanosheets and large-area/patterned nanofilms by thermal annealing of indium graphite mixture.
This paper proposes a compatible modelling method for finite element analysis of the laser welding autobody assemblies in crash analysis. The fracture modes weld were investigated application to modelling. A single stitch shape was modelled by cluster beam elements or hexahedron elements. model then applied cross tension test and lap shear under quasi‐static loading condition both experimentally numerically. Finite analyses carried out with respect type, number panel mesh size. numerical...
There are various different approaches in synthesizing graphene including chemical vapor deposition (CVD) and solid-phase method, where gas or solid type carbon source, to be converted into graphene, interacts with transition metals such as nickel copper. When any thin layer coated atop the polyacrylonitrile (PAN) film is pyrolyzed at a sufficiently high temperature, it impossible grow continuous large area owing dewetting, which has restricted subsequent utilization practical applications....
Abstract Strain engineering is a powerful tool for adjusting the electrical and optical properties of materials, particularly in 2D materials on flexible polymer substrates. However, current strain‐engineering techniques are primarily utilized thin substrates, with limited research thicker traditional In this study, enhancement resulting from strain effects 30‐nm‐thick ZnO films deposited SiO 2 wafers through N ion beam irradiation proposed. The beam, at an optimal energy level, induces...
Purpose: A miniature x-ray tube with the diameter of 10 mm has been fabricated using a carbon nanotube (CNT) field emitter, optimal design electron optics and target, vacuum sealing tube. The CNT emitter nm∼μm scale simpler cathode structure was used for miniaturization truncated conical shaped beryllium (Be) thin tungsten (W) coating were adopted to emit 3-dimensionally uniform as an isotropic radiation source. Anode grounded high voltage (HV) connection sealed within are advantages...