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A Resonance calculation using energy Spectral Expansion (RSE) method has been recently proposed in order to efficiently treat complicated heterogeneous geometry and resonance interference effect. In the RSE method, ultra-fine group spectra are generated from ultra-fine group calculations in homogeneous geometry, and the spectra are expanded by the orthogonal basis on energy based on the singular value decomposition. Then the transport calculation for expansion coefficients is numerically performed, and the ultra-fine group spectra in the target heterogeneous regions are reconstructed by the expansion coefficients and the orthogonal basis. In this study, the RSE method is applied to multi-cell geometries including UO2, MOX and water cells, in which the resonance interference effect between UO2 and MOX fuel cells appears. The validity of the RSE method is confirmed through comparison with the reference effective multi-group cross sections obtained from the direct ultra-fine group calculation in the target heterogeneous geometry.

AbstractA resonance calculation using a deterministic statistical geometry (DSTG) method has been developed to efficiently treat the double heterogeneity of coated fuel particles loaded in a high-temperature gas-cooled reactor. Using the DSTG method, neutron flux spatial distribution can be calculated in a heterogeneous geometry containing the randomly dispersed fuel particles and surrounding graphite matrix, which is consistent with statistical geometry in a Monte Carlo method.We applied the DSTG method to resonance calculations based on the equivalence theory and the ultra-fine-group energy treatment in the heterogeneous transport calculation code GALAXY-Z developed by Mitsubishi Heavy Industries, Ltd. In the GALAXY-Z code, DSTG can directly treat the heterogeneity of dispersed fuel particles in fuel compacts. The ultra-fine-group fixed-source DSTG calculation is applied to a high-energy range beyond 30 eV in which upscattering can be ignored. The fixed-source DSTG calculation is applied to a Dancoff-factor calculation for the equivalence theory in a low-energy range of less than 30 eV. In the low-energy range, the SHEM 361-group structure is applied, and the energy grids are detailed enough to allow a continuous treatment of the neutron spectrum. In other words, the upscattering effects and the resonance self-shielding effects are automatically considered in the multigroup transport calculation. The homogenized and collapsed multigroup cross sections of fuel particles are provided to lattice calculations of fuel elements.The comparison of reaction rates (effective cross sections) between GALAXY-Z and the continuous-energy Monte Carlo code MVP is carried out for fuel particles within a fuel element of the high-temperature engineering test reactor. The numerical results indicate that the present method well reproduces the fuel particle’s effective cross sections, k-infinity, and fission rate distribution calculated by MVP. [ABSTRACT FROM AUTHOR]

A retention analysis method for ferroelectric random access memory (FeRAM)was developed, in which read signal voltages from memory cells are measured. The method uses on-chip sample/hold circuits, an off-chip A/D converter, and memory large-scale integration testing equipment. FeRAM chip retention lifetime can be estimated on the basis of FeRAM read signal voltages after retention periods of one day and up. When used as a tool to estimate long-term data retention in FeRAM chips and to analyze fluctuations in memory cell characteristics, this method can provide useful information about FeRAM reliability. Index Terms--A/D converter, FeRAM, ferroelectric, memory, reliability, retention, sample/hold circuit, test.

An intramolecular tandem oxidative ring expansion-cyclization reaction of chiral bicyclo (4.1.0)-heptyl sulfides having alcohol or olefin in the C-6 side chain produces 1-oxaspiro(4.6)undecan-7-one and spiro(4.6)undecanes. This regio- and stereoselective asymmetric synthesis proceeds through a cation radical intermediate with preservation of chirality at C-6 carbon center. Ceric ammonium nitrate helps oxidize sulfides, leading to regioselective C-C bond cleavage and stereoselective intramolecular C-O or C-C bond formation.

Research has been conducted on [6-chloro-2-(4-chlorobenzoyl)-1H-indol-3-yl]-acetic acid. The synthesis of this selective cycooxygenase 2 inhibitor is described.

In this paper we propose an isomorphism criterion for cyclic balanced configurations defined over the same group Z n . It is shown that two such configurations are isomorphic if and only if there exists a group automorphism of Z n which maps one of the configurations onto the other. This result provides an easy isomorphism test for balanced cyclic configurations over the same cyclic group. [ABSTRACT FROM AUTHOR]

Analyzes the switching kinetics of polarization reversal using lead zirconate titanate (PZT) thin film capacitors for nonvolatile memories in terms of the Ishibashi model. Agreement between the polarization reversal ratio and the theoretical model of the first order dimensional domain growth.