Separation of Am(III) from Eu(III) by extraction based on in situ extractant formation of dithiocarbamate derivatives

A new solvent-extraction technique based on in situ formation of dithiocarbamate derivatives in order to separate Am(III) from Eu(III) was carried out. In this technique, the extractant is formed during the extraction course by the reaction between the organic materials, which are needed to synthesize the extractant. The synthesis of extractant in in situ extractant-formation method was carried out as follows. Di-substituted amine, such as dioctylamine (DOA), dibenzylamine (DBzA) and so on, and carbon disulfide (CS₂) were mixed in organic solvents, such as nitrobenzene, to produce dioctylammonium dioctyldithiocarbamate (DOA⁺·DODTC⁻), dibenzylammonium dibenzyldithiocarbamate (DBzA⁺·DODTC⁻), or so on. These organic solutions are also the organic phase in the solvent extraction, whereas the aqueous phase is 1.00 mol/dm³ (H, Na)NO₃ solution. The elements of Am(III) and Eu(III) were extracted into organic phase from different hydrogen ion concentrations of aqueous phase. The SF of Am(III)/Eu(III) is 3.2 × 10⁴ at pH_eq = 6.25 in DOA–CS₂/nitrobenzene system. This separation technique of Am(III) from Eu(III) by extraction based on in situ extractant formation has the following advantages. (a) It is unnecessary to take the chemical stability of extractant into account for storage purpose, and (b) Am(III) can be completely separated from Eu(III) by a single extraction procedure.     

Thermal conductivity of BaPuO3 at temperatures from 300 to 1500 K

Polycrystalline specimens of barium plutonate, BaPuO₃, have been prepared by mixing the appropriate amounts of PuO₂ and BaCO₃ followed by reacting and sintering at 1600 K under the flowing gas atmosphere of dry-air. The sintered specimens had a single phase of orthorhombic perovskite structure and were crack-free. The Debye temperature of BaPuO₃ was determined from the sound velocity and lattice parameter measurements. The elastic moduli were also determined from the longitudinal and shear sound velocity. The thermal conductivity of BaPuO₃ was calculated from the measured density at room temperature, literature values of heat capacity, and thermal diffusivity measured by a laser flash method in vacuum. The thermal conductivity of BaPuO₃ was roughly independent of the temperature and was almost the same magnitude as that of BaUO₃. This was markedly lower than the conductivities of other perovskite type oxides and was about one-tenth that of UO₂ around room temperature. The temperature dependence of the thermal conductivity of BaPuO₃ was found to be quite similar to that of BaUO₃.     

A modified model for non-newtonian viscosity behavior of Aureobasidium pullulans culture fluid

The culture fluid of the fungus Aureobasidium pullulans and the exopolysaccharide solution obtained by removal of the microbial cells exhibit a marked shear dependence of viscosity. The viscosity in a high shear rate region was a little higher than that predicted by a non-Newtonian viscosity equation derived previously on the basis of the concept of traveling force. In a sample exhibiting such high shear rate dependence, a hydrodynamic effect based on the fluid structure of the binding of contacting polymers and suspended microbial cells on viscosity becomes comparatively significant. A model for the shear rate dependence of the viscosity is needed to elucidate the mechanism of the viscosity behavior. A term concerning the increase in viscosity caused by the binding of polymers and the microbial cells suspended in a medium was added to the previous viscosity equation. The experimental shear dependence of the viscosity was well simulated by the modified viscosity equation.     

Species Identification and PCR-RFLP Analysis of Cytochrome b Gene in Cod Fish (Order Gadiformes) Products

ABSTRACT: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) profiles using the PCR product tRNA^Glu-cytochrome b of 9 standard cod fish, all of which are imported into Japan under the name "cod fish," were investigated as a means of rapid species identification of imported cod fish products. Endonuclease digestion using 4 restriction enzymes ( Alu I, Fok I, Mbo I, and Mse I) generated different digestion patterns for the standards, enabling species identification in imported cod fish products by comparison to the standards'RFLP profiles. Additionally, we conducted a more strict check by phylogenetic analysis on imported cod fish products with 13 standards (including 4 additional cod species from GenBank) using the mitochondrial cytochrome b gene (385 nt). Consequently, it was found that the PCR-RFLP method was sufficient for rapidly screening cod products, and in cases that require conclusive identification, phylogenetic analysis was the most suitable.     

铝酸钙水泥对焦宝石基喷涂料性能的影响

以焦宝石颗粒及细粉为主要原料，铝酸钙水泥为结合系统。分别研究了不同铝酸钙水泥含量对焦宝石基喷涂料性能的影响。结果表明．焦宝石基喷涂料的抗折强度随着铝酸钙水泥含量的增加呈上升趋势。但经过600℃、1000℃和1300℃烧结后的焦宝石基喷涂料的耐压强度随着铝酸钙水泥含量的增加呈先增加后减小的趋势。     

Carrier transport and structural properties of polysilicon films prepared by layer-by-layer technique

Polycrystalline silicon (poly-Si) films have been deposited on glass substrates by a layer-by-layer technique at very low temperature, 300°C, using fluorinated precursors. The electronic transport was characterized by Hall effect and conductivity measurements over a wide temperature range, 100 K to 400 K. The structure of the materials is a function of the film thickness. The measured Hall mobility increases as the thickness increases. The Hall mobility Arrhenius plot shows linear dependence with a negative slope over the temperature range examined, suggesting that carrier conduction is limited by grain boundary barriers.     

Numerical diffusion in single-phase multi-dimensional thermal-hydraulic analysis

Higher-order difference schemes, including QUICK and its related schemes, are discussed through several numerical experiments with the focus on their performance to reduce numerical diffusion and to suppress local unphysical oscillations. Finally, these schemes are applied to in-vessel thermal-hydraulic analysis and their effectiveness on the analysis is demonstrated.     

Estimation of creep crack growth rate in IN-100 based on the Q* parameter concept

Since the high-strength Ni-based superalloy, cast IN-100, is considered to be brittle at high temperatures, the stable creep crack growth region is limited. Therefore, technically, it is very difficult to perform creep tests and there are few experimental results on the creep crack growth behaviour of this material. We performed creep crack growth tests using Ni-based superalloy, cast IN-100, and derived the Q* parameter for this material, which characterizes the creep crack growth rate. Using this Q* parameter, we derived a law for the creep rupture life of this material.     

Effect of an additive on the radiation resistance of polyethylene and ethylene–propylene copolymer

In low-density polyethylene containing the additive propylfluorancene, radiation energy received by polyethylene is transferred to propylfluorancence, and the production of radicals at 77 K in polyethylene is suppressed. Propylfluoranncene also increases the rate of the decay of radicals of polyethylene at room temperature. The depression of radical production and accelaration of radical decay at room temperature results in the depression of gas production and crosslinks at room temperature in low-density polyethylene containing propylfluorancene. Similar results were obtained in ethylen–propylene copolymer containing the same additive.