[en] In this work, large-zone sodium-void effects are studied in detail in the presence of many singularities, namely, control rods (CRs) and control rod positions (CRPs). The results of measurements and calculations are compared by CIE (calculation/experiment) values, which are 1.07 when the voided core region is free of singularities. When the void region includes CPRs, which are concurrently voided, the CIE value deteriorates and varies from 0.35 to 1.58. The agreement can be improved considerably by correcting the reactivity worth of the sodium contained in the CRPs with the aid of experimental data (CIE = 1.00 +- 0.15). The heterogeneity correction for the fuel elements was performed by the plate-cell vollision probability code KAPPER. (GL)

No abstract available

[en] We investigate the possible range of the isotopic ratios of carbon and nitrogen in the mixture of different layers of supernovae with Z Z_[odot] and Z = 0.1Z_[odot]. We carry out the postprocessing nucleosynthesis calculations using the evolution profile of 4 M_[odot] He stars and that of the following supernova explosions to obtain abundance distributions. Main difference due to the metallicity is found in the range of the isotopic ratios of the mixture between the He/C-layer and the He/N-layer. Most of the isotopic ratios of SiC type X grains are inside the range of the isotopic ratios of the mixture between the He/C-layer and the He/N- or Si/S-layer of the supernova models

[en] The nonrelativistic Kepler problem modified by an inverse cube force with a precessing elliptical orbit is considered on the co-ordinate system generated by the rotating Laplace-Runge-Lenz vector. Corresponding to the character of the orbit, a new variable named ''precessing eccentric anomaly'' is introduced. Using the variable it will be defined Kepler's equation for the modified Kepler problem and analysed its precessing orbit in terms of time

[en] For any planar motion a constant of the motion called generalized Laplace-Runge-Lenz vector is defined with the matrix representation. Taking the tensor product of the generalized vector with itself, the conserved symmetric tensor corresponding to the Hamiltonian of a two-dimensional isotropic harmonic oscillator is simply constructed

No abstract available

[en] The authors developed a three-dimensional display technique for blood vessels related to soft tissues, using MR images generated by the three-dimensional Fourier transform method or multisection method. An application of this study for neurosurgery provided satisfactory results. In this paper they describe this display technique and its clinical practice, including procedures (1) to enhance blood vessels by nonlinear filter capable of detecting three-dimensional line patterns without losing the form of soft tissues, (2) to generate three-dimensional images by the numerical projection, and (3) to present three-dimensional display utilizing the dynamic or binocular parallex (animation display or stereoscopic display). This technique facilitates the recognition of the three-dimensional structure of blood vessels related to soft tissues

[en] Paper presents the results of efforts to study possibility to ensure thorium fuel cycle based on Pa-U fuel produced during ThO₂-blanket irradiation by fusion neutrons. The mentioned fuel cycle is characterized by high proliferation resistance due to production of ²³²U isotope. One analyzed the mentioned cycle applicability in a gas reactor and high burnup of fuel in reactor core with high resource

[en] Analytical methods for RCRA listed elements on Portland cement type waste have been employed using both microwave and open hot plate digestions with subsequent analysis by inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), graphite furnace atomic absorption (GFAA) and cold vapor atomic absorption and fluorescence (CVAA/CVAFS). Four different digestion procedures were evaluated including an open hot plate nitric acid digestion, EPA SW-846 Method 3051, and 2 methods using modifications to Method 3051. The open hot plate and the modified Method 3051, which used aqua regia for dissolution, were the only methods which resulted in acceptable data quality for all 14 RCRA-listed elements. Results for the nitric acid open hot plate digestion were used to qualify the analytical methods for TRU waste characterization, and resulted in a 99% passing score. Direct chemical analysis of TRU waste is being developed at Los Alamos National Laboratory in an attempt to circumvent the problems associated with strong acid digestion methods. Technology development includes laser induced breakdown spectroscopy (LIBS), laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), dc arc CID atomic emission spectroscopy (DC-AES), and glow discharge mass spectrometry (GDMS). Analytical methods using the Portland cement matrix are currently being developed for each of the listed techniques. Upon completion of the development stage, blind samples will be distributed to each of the technology developers for RCRA metals characterization

[en] The ratio of the real to imaginary parts of the forward amplitudes is investigated under the assumption that the ratios of the two components of Pomeron are energy-independent. The theoretical values are in good agreement with the FNAL and ISR data. (author)