Nuclear data sensitivity/uncertainty analysis for XT-ADS

The XT-ADS, an accelerator-driven system for an experimental demonstration, has been investigated in the framework of IP EUROTRANS FP6 project. In this study, the sensitivity and uncertainty analyses were performed to comprehend the reliability of the XT-ADS neutronic design.     

Impact of fertilizer on a small watershed of Lake Biwa: use of sulfur and strontium isotopes in environmental diagnosis

Sulfur and strontium isotopes (delta(34)S and (87)Sr/(86)Sr) were determined in 39 river water samples collected over three different cultivation periods (April, May, and June), and in several materials used for comparison (fertilizers, detergents, soils, irrigation and agricultural waters), to evaluate the impact of fertilizers on a small agricultural watershed of Lake Biwa, in central Japan. delta(34)S values in river water decreased (from +5.8 to -2.0 per thousand) with increasing SO(4) concentrations (3.8 to 93.2 ppm) from upstream to downstream of the watershed. Comparison of river water S isotopes with those of possible source materials indicates that the enrichment of SO(4) can be attributed to the dissolution of two kinds of fertilizers: (1) compound fertilizers commonly used in this area and (2) ammonium sulfate which is applied on a small scale. In contrast, (87)Sr/(86)Sr values of river water decreased with time from April (avg. 0.71163), through May (avg. 0.71139), to June (avg. 0.71127). The tendency of the sample plots on the (87)Sr/(86)Sr vs. 1/Sr diagram suggests a time-dependent increase in the contribution of soil water to the river, which is partly affected by the Sr-bearing fertilizers. It is suggested that a maximum of 25% of dissolved Sr is derived from these fertilizers, while more than 75% of it is of rock origin. Mass balance calculations permitted us to evaluate the proportion of fertilizer contribution in each river. Combined use of S and Sr isotopes together with concentration data could be a new environmental diagnosis technique for rivers and soils in localized watersheds.     

Study on environmental effect on fatigue and creep-fatigue strength of 316FR stainless steel in sodium at elevated temperature

Low-carbon 316 stainless steel with medium-nitrogen (316FR) is considered as the principal structural material for next generation fast breeder reactor (FBR) plants in Japan. The material strength standard and the creep-fatigue life evaluation method for 316FR have been developed. However, they are based on the results of material tests in air, while actual structural material will be used mainly in liquid sodium environment in the plants. In order to clarify the environmental effect, cyclic bending tests were carried out with and without hold time in sodium. Tested materials were 316FR and conventional 304 and 316 stainless steels. Weld metal of 316FR was also tested. As a result, it was found that fatigue and creep-fatigue lives of 316FR in sodium were larger than those in air and no explicit consideration of the environmental effect is necessary in design. It was also found that the life evaluation method based on the ductility exhaustion concept is applicable to creep-fatigue life assessment in sodium.     

Monolithic four-channel photodiode/amplifier receiver array integrated on a GaAs substrate

A four-channel optoelectronic integrated receiver array operating at the wavelength near 850 nm has been fabricated on a single GaAs substrate by using metal-semiconductor-metal (MSM) photodiodes (PD's) and metal-semiconductor field-effect transistors (MESFET's). The largest integration scale for a monolithic receiver and uniform characteristics among circuit channels have been achieved due to the structural simplicity and the process-compatibility of this array. Also, an extremely small capacitance of MSM-PD, 0.10 pF, has lead us to obtain a high-speed operation up to a bit rate of 1.5 Gbit/s, NRZ, and a low noise characteristic exhibiting an equivalent input noise current as small as 5 pA/Hz^1/2. These results have indicated the suitability of MSM-PD/MESFET's circuits for large-scale multichannel optoelectronic integration of receivers.     

Synthesis of 2-alkyloyl-1,4,3,6-dianhydrosorbitol-5-sulfates and evaluation of the surface active properties

New anionic surfactants 2-alkyloyl-1,4,3,6-dianhydrosorbitol-5-sulfates were synthesized by sulfation of 2-alkyloyl-1,4,3,6-dianhydrosorbitol. Studies on the surface active properties such as surface tension, dispersibility and emulsifiability of these surfactants were carried out. The results showed these surfactants are better dispersants and emulsifiers than Span 80 and Span 85.     

Studies on chitin. VI. Binding of metal cations

The adsorption abilities of chitin and its congeners with two series of degrees of deacetylation prepared by two different deacetylation procedures were compared. Among the polysaccharides obtained by the heterogeneous method, those with higher amino group content had higher adsorption ability. Plots of collection percentages versus amino group content, however, did not give straight lines. The plot for the chelation on the congeners that were prepared by homogeneous hydrolysis had a maximum at about 50% amino group content, and the value was higher than that for the sample with the highest amino group content, which was prepared by heterogeneous hydrolysis. These results suggest that the polysaccharides with about 50% amino group content obtained by the homogeneous procedure are potentially useful for the removal of metals.     

Development of water pipe cooling system for power cables intunnels

A full-size test line was constructed to study the water pipe cooling system for a bulk-power transmission line installed in a tunnel. Based on the test data and their analysis, a technique for designing the system has been established. The results have indicated an effective layout of the cooling pipes in the tunnel, and have validated the accuracy of the computer models to determine thermal characteristics of the tunnel system. An efficient control method to operate the cooling system according to the load changes of the cables was developed. The chosen layout is shown to be more effective than the dispersed layout because it accelerates the air convection and makes the air temperature more uniform. Furthermore, the thermal convection resistance between the tunnel wall and the air is reduced. It was also verified that the air temperature distribution along the vertical shaft could be predicted by thermal convection analysis. This cooling system is scheduled to be applied to a 154 kV power cable line in 1990     

Long-term results of Watson-Jones tenodesis of the ankle. Clinical and radiographic findings after ten to eighteen years of follow-up

Thirty-seven chronically unstable ankles in thirty-six patients were operated on with use of a Watson-Jones tenodesis. Thirty-four ankles (thirty-three patients) were followed for a mean duration of thirteen years and eight months (range, ten to eighteen years) after the operation. There were nine male and twenty-four female patients. The mean age of the patients was thirty-one years (range, fourteen to fifty-seven years) at the time of the operation and forty-four years (range, twenty-eight to seventy years) at the time of the latest follow-up. At the time of the most recent follow-up evaluation, twenty-seven patients (twenty-eight ankles) were examined directly by one of us and twenty-five patients (twenty-six ankles) also were evaluated radiographically. The other six patients were interviewed, with use of a questionnaire, by telephone. Of the thirty-four ankles, nineteen had an excellent result (grade 1), eleven had a good result (grade 2), three had a fair result (grade 3), and one had a poor result (grade 4) according to the rating system of Good et al. The mean score (and standard deviation) on the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society for the twenty-eight ankles that were examined directly by one of us was 90 +/- 9.3 points (range, 68 to 100 points). Progression of an exostosis at the edge of the joint was detected in eighteen (69 percent) of the twenty-six ankles that were examined radiographically, but narrowing of the joint space was not seen in any ankle. No relationship was detected between the clinical results and radiographic osteoarthrotic changes or the duration of follow-up. The results did not deteriorate over the long term.     

Low resistivity transparent conducting Al-doped ZnO films prepared by pulsed laser deposition

A series of AZO films were grown on glass substrates by a method of pulsed laser deposition using a split target divided into AZO (Al₂O₃: 1 wt.%) and AZO (Al₂O₃: 2 wt.%). The film deposition took place at a substrate temperature of 230 °C within a magnetic field applied perpendicularly to the plume. To suppress the droplet generation caused by the intense laser energy, the laser energy density was reduced to 0.75 J/cm² (15 mJ). For an approximately 280-nm thick-AZO film grown at a target-to-substrate distance of 25 mm, we obtained the lowest resistivity of 8.54×10⁻⁵ Ω·cm and an average transmittance of more than 88% in the visible range. In the cross-sectional TEM observation and XRD spectra, the regularity in the crystal growth was generated immediately from the interface between the substrate and the film.     

Estimation and characterisation of major royal jelly proteins obtained from the honeybee Apis merifera

Royal jelly (RJ) contains many components, including proteins. We focused on major royal jelly proteins (MRJPs) under natural conditions, and attempted to determine the content ratios and molecular forms of MRJPs by size-exclusion HPLC, SDS–PAGE, 2-DE and MALDI TOF/TOF MS. Soluble RJ proteins were extracted by dialysis followed by several centrifugation techniques. Soluble RJ proteins were universally separated into five peaks (640 kDa, 280 kDa, 100 kDa, 72 kDa and 4.5 kDa) by size-exclusion HPLC on a Superose 12 column. Among these peaks, both the 280 kDa and 72 kDa peaks were major, but the intensity of the 280 kDa peak differed markedly among original RJ samples (n = 70). The main 280 kDa protein was separated into a 55 kDa band by reducing and non-reducing SDS–PAGE. This protein was also separated into multiple spots ranging from pH 4.2 to 6.5 by 2-DE. These spots were identified as MRJP 1 by MALDI TOF/TOF MS. From these results, MRJP 1 was thought to comprise an oligomer complex linked by non-covalent bonds under natural conditions. Another major protein, the 72 kDa peak on Superose 12 HPLC, was identified as MRJP 2.