Design of the dummy coil for magnet power supply

It is necessary to test it on a dummy coil, before using a magnet power supply (MPS) to energize a Poloidal Field (PF) coil in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The dummy coil should accept the same large current from the MPS as the PF coil and be within the capability of the utilities located at the KSTAR site. Therefore a coil design based on the characteristics of the MPS and other restrictive conditions needed to be made. There are three requirements to be met in the design: an electrical requirement, a structural requirement, and a water cooling requirement. The electrical requirement was that the coil should have an inductance of 40 mH. For the structural requirement, the material should be non magnetic. The coil support structure and water cooling manifold were made of SUS 304. The water cooling requirement was that there should be sufficient flow rate so that the temperature rise ΔT should not exceed 12 °C for operation at 12.5 kA for 5 min. Square cross-section hollow conductor with dimensions of 38.1 mm × 38.1 mm was used with a 25.4 mm center hole for cooling water. However, as a result of tests, it was found that the electrical and structural requirements were satisfied but that the water cooling was over designed. It is imperative that the verification will be redone for a test with 12.5 kA for 5 min.     

Semantic Hashtag Relation Classification Using Co-occurrence Word Information

Wireless Personal Communications - Users using social networking service (SNS) may express their thoughts and feelings using simple hashtags. Hashtags are related to other hashtags and images that...     

Evolution of strain states and textures during roll-cladding in STS/Al/STS sheets

The evolution of strain states and textures during roll-cladding of three plies of sheets comprising ferritic stainless steel (STS), aluminum (Al) and ferritic stainless steel was investigated by measurements of crystallographic textures and by simulations with the finite element method (FEM). Because the deformation mainly occurs in the Al layer during roll-cladding, the present investigation was focused on the Al layer located at the middle of clad samples. Roll-cladding of STS/Al/STS sheets led to the development of a strong through thickness texture gradient in the Al sheet which was characterized by shear textures at the surface layer and rolling textures at the center layer. The temperature of the cladding operation played an important role in the evolution of textures.     

In-plane strains measurement by using the electronic speckle pattern interferometry

Two-dimensional in-plane displacements and strains are measured using an electronic speckle pattern interferometry (ESPI) system based on the dual beam speckle interferometric method. Different types of specimens are used: a flat plate, a cracked-plate, and plate with a central hole of 12 mm diameter. Two-dimensional fringes obtained from real-time images are analyzed by an image analyser. The values of in-plane strains obtained by the ESPI technique show high accuracy compared with those measured by strain gages.     

Isolation and Purification of a Novel Deca-Antifungal Peptide from Potato (Solanum tuberosum L. cv. Jopung) Against Candida albicans

In a previous study, an antifungal protein, AFP-J, was purified from tubers of the potato (Solanum tuberosum cv. L Jopung) and by gel filtration and HPLC. In this study, the functional peptide was characterized by partial acid digestion using HCl and HPLC. We obtained three peaks from the AFP-J, the first and third peaks were not active in the tested fungal strain. However, the second peak, which was named Potide-J, was active (MIC; 6.25 μg/mL) against Candida albicans. The amino acid sequences were analyzed by automated Edman degradation, and the amino acid sequence of Potide-J was determined to be Ala-Val-Cys-Glu-Asn-Asp-Leu-Asn-Cys-Cys. Mass spectrometry showed that its molecular mass was 1083.1 Da. Finally, we confirmed that a disulfide bond was present between Cys(3) and Cys(9) or Cys(10). Using this structure, Potide-J was synthesized via solid-phase methods. In these experiments, only the linear sequence was shown to display strong activity against Candida albicans. These results suggest that Potide-J may be an excellent candidate compound for the development of commercially applicable antibiotic agents.     

Surface crack initiation in 2Y-TZP ceramics by low temperature aging

Surface crack initiation in 2Y-TZP specimens during aging at 250°C was investigated. Surface upheaval due to the isothermal phase transformation appeared on aging, in order to reduce the change of strain free energy for the transformation. The nucleation of a microcrack was induced by surface upheaval at the beginning of aging, and the microcrack was grown to a macrocrack with aging. The crack surface created by isothermal phase transformation shows a completely intergranular fracture mode. The propagation of phase transformation from surface to interior during aging is continous and uniform and the transformed region shows a porous microstructure.     

Density correlation of solubility of C. I. disperse orange 30 dye in supercritical carbon dioxide

The solubility of C. I. Disperse Orange 30 (O30) dye in CO₂ has been measured by using a closed-loop (batch) solid-fluid equilibrium apparatus at temperatures between 313 and 393 K and at pressures between 11 and 33 MPa. Kumar and Johnston’s equation based on Chrastil’s concept has been used to describe the experimental solubility data. The solubility versus density plot appears much simpler than the solubility versus pressure plot. The isotherms are nearly straight and parallel to each other, as seen in the previous studies. Peng-Robinson equation of state (PR EOS) has also been used successfully in modeling the dye solubility in supercritical carbon dioxide as a function of pressure or density of the fluid phase. The validity of this method has been verified by the vapor pressure calculation. This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University.