[en] The Atomic Energy Council (AEC) is the regulatory body of ionization radiation protection in Taiwan. To effectively control the safety in ionization radiation, AEC brought into force the Ionization Radiation Protection Act on 1 February, 2003 with clear statements of the penalty for violating the Law. The Article 5 of the Act provides: In order to limit the radiation exposure from radiation sources or practices, the Competent Authority shall refer to the latest standards of the International Commission on Radiological Protection to lay down the Safety Standards for Protection against Ionizing Radiation. Thus, AEC is going to draft new safety standards of ionization radiation protection of Taiwan according to ICRP Publication 60. The Institute of Nuclear Energy Research (INER), the governmental institute working on ionization radiation research in Taiwan, took the responsibility of assisting AEC in establishing guidelines on the control of internal radiation exposure and responding to the regulations in the new standards as soon as possible. So, according to the recommendations of ICRP Publications 60, 66,67,68,69,71,78,88, and IAEA Safety Standard Series No. RS-G- 1.1 and 1.2, INER undertook researches on the internal radiation exposure control and dose evaluations for INER's radiation workers as well as dose evaluations for the general public. The research accomplishments not only can be the reference of AEC when making new standards, but also can be followed by other radiation protection businesses. (Author) 23 refs

[en] Using the numerical renormalization group method, we study a generalized two-channel Kondo model where the impurity has a quadrupole moment (pseudospin) and a magnetic moment (flavor). This model may be of relevance to the Ce ions in CeB₆ and the Cu ions in cuprate superconductors. We find that the nontrivial fixed point of the two-channel Kondo model is unstable against flavor exchange coupling. The system flows to a non-Fermi-liquid fixed line. In the presence of a double tensor interaction, which breaks particle-hole symmetry, the system flows to a Fermi-liquid fixed line

[en] The complexes, hexakis(alkyl isocyanide) technetium(I) hexafluorophosphate [Tc(CNR)₆]PF₆ (where R = tert-butyl, methyl, cyclohexyl, and phenyl), have been prepared by reduction of the pertechnetate ion with aqueous sodium dithionite (Na₂S₂O₄) in the presence of the isocyanide ligands. These complexes have been characterized by elemental analysis, optical, ir, and ¹H NMR spectroscopy, conductance, cyclic voltammetry, and field desorption mass spectrometry

[en] In order to extend the density-matrix renormalization-group (DMRG) method to two-dimensional systems, we formulate two alternative methods to prepare the initial states. We find that the number of states that are needed for accurate energy calculations grows exponentially with the linear system size. We also analyze how the states kept in the DMRG method manage to preserve both the intrablock and interblock Hamiltonians, which is the key to the high accuracy of the method. We also prove that the energy calculated on a finite cluster is always a variational upper bound

[en] This presentation will focus on current work in the Ames Laboratory where laser ablation is being used for both analytical sampling and metal surface cleaning. Examples will be presented demonstrating the utility of optical spectroscopy for monitoring laser ablation processes.

[en] The magnetocrystalline anisotropy energy (MAE) of NdCo₅ was studied from first principles using the full potential linearized augmented plane wave (FLAPW) method. The LDA+U method was used to take into account the effects of strong electronic correlations of 4f states. In agreement with experiments, the magnetization points into the crystallographic a-axis in the basal plane. The in-plane MAE was also studied and the correct magnetization direction was arrived at but the magnetic anisotropy constant K₃ was about one order of magnitude smaller than the experimental value. The microscopic origin of the MAE in NdCo₅ was studied using the orbital moment anisotropy (OMA) and its evolution with lattice geometry. Spin-reorientation transitions in NdCo₅ could be well explained by the competition in OMA between Co and Nd sites. These results show that the non-equivalent Co sites behave differently with changes in lattice geometry, and the Co_3g sites are of the same importance as Nd sites in deciding the in-plane magnetocrystalline anisotropy of NdCo₅. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

[en] Three dimensional characterized unit was used for TRISO particle with UN as the kernel to analyze the influence of PyC layers and internal pressure on the thermal mechanical performance of TRISO coated fuel particles by using the multi physics coupling software COMSOL. The influence of operation conditions including steady state and reactivity introduced accident (RIA) conditions on the thermal mechanical performance of TRISO particle was conducted. The results indicate that the structure integrity of SiC layer was maintained but the IPyC layer was failed in steady state condition. Thermal expansion is a dominant factor resulting in the loss of structure integrity of the TRISO coated fuel particle under RIA condition. (author)

[en] A novel composite hydrogen sensor, consisting of Pd nanoclusters/TiO₂ nanotube arrays, was fabricated and evaluated at room temperature. The Pd nanoclusters layer was deposited on top surface of the nanotube arrays by using a direct current (DC) magnetron sputtering method. Resistive response of the composite sensors to 0.5% hydrogen was measured. Experimental results indicated that the Pd nanoclusters can quickly and continually form or break multiple passages by absorbing or desorbing hydrogen, so that the composite hydrogen sensors have promising hydrogen sensitivity at room temperature. (paper)

[en] Zr-Si-N films were deposited on silicon and steel substrates by cathodic vacuum arc with different N₂/SiH₄ flow rates. The N₂/SiH₄ flow rates were adjusted at the range from 0 to 12 sccm. The films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), hardness and wear tests. The structure and the mechanical properties of Zr-Si-N films were compared to those of ZrN films. The results of XRD and XPS showed that Zr-Si-N films consisted of ZrN crystallites and SiN_x amorphous phase. With increasing N₂/SiH₄ flow rates, the orientation of Zr-Si-N films became to a mixture of (1 1 1) and (2 0 0). The column width became smaller, and then appeared to vanish with the increase in N₂/SiH₄ flow rates. The hardness and Young's modulus of Zr-Si-N films increased with the N₂/SiH₄ flow rates, reached a maximum value of 36 GPa and 320 GPa at 9 sccm, and then decreased 32 GPa and 305 GPa at 12 sccm, respectively. A low and stable of friction coefficient was obtained for the Zr-Si-N films. Friction coefficient was about 0.1.

[en] In this work, Sm and Sc co-doped Bi_1_−_xSm_xFe_1_−_ySc_yO_3 (x  =  0.00–0.20; y  =  0.03) ceramics are fabricated by a rapid liquid phase sintering method, in order to develop single-phase multiferroics with large magnetization and polarization. X-ray diffraction and Raman spectroscopic studies reveal that the ceramics are single-phase with a structural transition from rhombohedral to orthorhombic structures near x  = 0.15. Electric and magnetic measurement results indicate that the transition significantly enhances the multiferroic properties, which stems from the Sm/Sc doping induced collapse of space-modulated spin structure and internal structural distortion. At an optimized composition of Bi_0_._8_5Sm_0_._1_5Fe_0_._9_7Sc_0_._0_3O_3 (x  =  0.15), a remanent polarization of 16.5 μC cm"−"2, a magnetization 0.2020 emu g"−"1, and a magnetodielectric effect of 0.46% can be obtained. These results clearly demonstrate a potential application for Sm/Sc doped BiFeO_3 ceramics in the field of multiferroic devices. (paper)