Fabrication and application of microcapsules including fluorescent magnetic particles for crack inspection of pipes

Ito, Fuyumi; Nishimura, Akihiko

Transactions of the Materials Research Society of Japan, 38(4), p.667 - 672, 2013/12

https://doi.org/10.14723/tmrsj.38.667

We are proposing Magnetic particle Testing (MT) using fabricated micro capsules by the hand-shake method. Here a test piece magnetized beforehand is immersed in liquid dispersed with magnetic particles. Fluorescent pigment adheres to the magnetic particles. So, MT is able to facilitate the crack visually as long as a certain amount of magnetic particles are holding the fluorescent pigment. However, separation between particle and pigment degrades transparency in liquid. Finally the hazy liquid makes difficult to find any crack. To solve this problem, we propose to use the Magnetic Particle Micro Capsule (MPMC). In addition, to applying this MPMC, the surround of the nuclear power plant should be confirmed. To confirm inside wall, the Laser Induced Breakdown Spectroscopy (LIBS) was applied.

Focused microbeam irradiation effects in transmission CVD diamond film detectors

Kada, Wataru; Kamiya, Tomihiro; Iwamoto, Naoya; Onoda, Shinobu; Grilj, V.*; Skukan, N.*; Makino, Takahiro; Koka, Masashi; Sato, Takahiro; Jaki, M.*; et al.

Transactions of the Materials Research Society of Japan, 38(2), p.279 - 282, 2013/07

https://doi.org/10.14723/tmrsj.38.279

Diamond is interested by many researchers as an excellent candidate material with advantages in the radiation-hardness. For the time-resolved detection of single-ions with several hundred MeV, transmission E detector using thin film CVD diamond is now under investigation for the futuristic utilization in a microbeam line of the AVF cyclotron at JAEA/Takasaki TIARA facility as replacing materials of the beam extraction window. In this research, a Single Crystalline (SC) 50 m thick CVD diamond film ion detector was fabricated for the investigation of the responses and radiation hardness under the focused ion microbeam irradiation. Transient Ion Beam Induced Current (TIBIC) experiment was executed by single hit irradiation of 15 MeV O scanning area of 50 m and the transient signals with time width of several nano-secounds were consecutively recorded by a high speed (15 GHz) Digital Storage Oscilloscope during the irradiation. The decreases in the individual pulse height was observed by increasing the total amount of the ion dose irradiated in the focused area. These changes were recovered in temporal conversion of applied bias voltages thus trend of decrease were able to be controlled by changing bias settings and irradiation conditions during the experiments.

Fabrication of highly-oriented silicide film on Si substrate treated by low-energy ion beam

Hamamoto, Satoshi*; Yamaguchi, Kenji; Hojo, Kiichi

Transactions of the Materials Research Society of Japan, 38(1), p.89 - 92, 2013/03

https://doi.org/10.14723/tmrsj.38.89

Nanoparticle formation by tungsten ion implantation in glassy carbon

Kato, Sho; Yamaki, Tetsuya; Yamamoto, Shunya; Hakoda, Teruyuki; Kawaguchi, Kazuhiro; Kobayashi, Tomohiro*; Suzuki, Akihiro*; Terai, Takayuki*

Transactions of the Materials Research Society of Japan, 38(1), p.81 - 84, 2013/03

https://doi.org/10.14723/tmrsj.38.81

Nanoparticles were formed by 100 keV tungsten-ion implantation in unpolished glassy carbon substrates at nominal fluences of - ions/cm. The implanted samples were analyzed by Rutherford backscattering spectrometry, X-ray photoelectron spectroscopy, hydrodynamic voltammetry using a rotating disk electrode, and field emission scanning electron microscopy. A significant sputtering effect changed the depth profile during the course of irradiation and limited the amount of tungsten retainable in the substrate in agreement with our calculated distributions. The nanoparticles were composed of tungsten carbide and dispersed uniformly with diameters of around 10 nm.

X-ray emission spectroscopy of Ta-related oxides

Yoneda, Yasuhiro; Yoshii, Kenji; Suzuki, Chikashi

Transactions of the Materials Research Society of Japan, 37(4), p.579 - 582, 2012/12

https://doi.org/10.14723/tmrsj.37.579

We performed X-ray Emission spectroscopy (XES) by using a double crystal spectrometer. Ta-L and L emission lines of Ta-related materials of Ta-metal, TaO, LiTaO, and KTaO were measured. XES is one of the most important spectroscopies to make a remarkable progress utilizing third generation synchrotron radiation sources. Here, I discuss some aspects of XES in Ta compounds of recent experimental data. We also discuss an azimuth dependence of resonant X-ray emission spectra (RXES) of a single-crystal KTaO. The precise measurement by the double crystal spectrometer has observed change of the electronic structure by crystal orientation. Since electronic structure observation is a local probe, it can detect minute lattice deformation.

Fabrication of polymer optical waveguides for the 1.5-m band using proton beam writing

Miura, Kenta*; Sato, Takahiro; Ishii, Yasuyuki; Koka, Masashi; Takano, Katsuyoshi*; Okubo, Takeru; Yamazaki, Akiyoshi; Kada, Wataru; Yokoyama, Akihito; Kamiya, Tomihiro; et al.

no journal, , 

Multiscale computational approach of grain size effect on plastic deformation

Tsuru, Tomohito; Aoyagi, Yoshiteru*; Shimokawa, Tomotsugu*; Kaji, Yoshiyuki

no journal, , 

Recent progress in grain boundary engineering allows the effective control of grain scale and microstructure in metallic systems, improving bulk material properties. It has been possible to produce nano-crystalline and ultrafine-grained metals with submicron grain size. Mechanical properties of the nano structured metals cannot be predicted based on assumptions of the average quantity of collective motion of dislocations, and therefore it is increasingly necessary to understand the role of each grain and its effect on the plastic deformation. In the present study, a multiscale computational modelling based on atomistic and crystal plasticity (CP) analysis is developed to capture the effect of grain size and macroscopic mechanical properties.

Radius control of ceramic nano fiber synthesized from precursor polymer by two steps irradiation method using ion and electron beams

Sugimoto, Masaki; Yoshikawa, Masahito; Tsukuda, Satoshi*; Seki, Shuhei*

no journal, , 

A ceramic nano fiber was synthesized from a thin film of precursor polymer using ion-beam irradiation techniques. We fabricate the new control method of the nanofiber radius using ion and electron beams irradiation. Polycarbosilane (PCS) film was irradiated by 490 MeV Os ion beams, subsequently, irradiated by 2 MeV EB. After irradiation, the thin film was developed by solvent, subsequent pyrolysis converted polymeric into inorganic SiC nano fibers. The radius of PCS nano fiber increased with the dose of EB irradiation. The two step irradiation method using ion and electron beams enables to increase the radius of the nano fiber; therefore it has been expected to be a standing nano fiber as high efficiency catalyst materials.

Dopant activation by solid phase epitaxy in silicon and germanium

Johnson, B. C.; Oshima, Takeshi; McCallum, J. C.*

no journal, , 

Solid phase epitaxy (SPE) is an important process used for the formation of shallow junctions on a low thermal budget. On annealing, atoms reorder at the crystal-amorphous (c-a) interface via a bond breaking mechanism, possibly mediated by dangling bonds. When the c-a interface passes a dopant, it is incorporated onto an electrically active lattice site, shifts the Fermi level and enhances the SPE velocity. The generalized Fermi level shifting (GFLS) model describes this process with two fitting parameters: the energy level, E, and degeneracy, g, of the SPE defect. High dopant concentrations induce a uniaxial strain in the plane of the c-a interface and is also expected to effect the SPE rate. In this study, we successfully incorporate this into the GFLS model. SPE data for a broad range of dopant concentrations and species in both silicon and germanium are investigated. Although the dopant concentrations are similar, the SPE of Ge in Sb rates are noticeably lower. Uniaxial compressive stress arising from the large Sb atoms causes this discrepancy.

Radiation-induced crosslinking of poly(butylene adipate-co-telephtalate)

Nagasawa, Naotsugu; Akaoka, Masato*; Tamada, Masao; Mitomo, Hiroshi*; Taguchi, Mitsumasa

no journal, , 

Poly(butylene adipate-co-terephthalate) (PBAT) synthesized by polycondensation is a completely biodegradable aliphatic and aromatic polyester. PBAT is decomposed into harmless water and carbon dioxide by microorganisms in the soil. Therefore, PBAT is expected to be utilized for applications in trash bags and disposable packages. The high thermal stability is, however, necessary for expanding their applications. To improve the thermal stability, radiation effect on crosslinking of PBAT was investigated. The PBAT films with and without triallyl isocyanulate (TAIC) as a crosslinker were prepared and then irradiated with electron beam. The gel content was estimated by weighing insoluble part of the crosslinked PBAT film after immersion in chloroform. Gelation of the irradiated PBAT with 3% TAIC is higher than that of PBAT without TAIC at the dose range from 10 to 200 kGy. This result indicates that the crosslinking structures are effectively formed when PBAT films were irradiated with TAIC. The thermal stability of the crosslinked PBAT films was estimated by thermomechanical analyzer. The modified films have excellent properties as demonstrated by retention of original shape even at temperatures higher than melting point (115 C). The biodegradability, which was estimated by enzyme test using Lipase AK, of the crosslinked PBAT film was similar to that of non-irradiated one. As a result, the crosslinked PBAT after usage would undergo biodegradation by naturally existing microorganisms. Therefore, the crosslinked PBAT was found to be thermal stable and biodegradation enough for expanding applications.