Polarizer with Nonrectangular Grooves in the HE11 Mode Transmission Line

This paper presents experimental results on polarizers with nonrectangular grooves to be used in high power millimeter wave transmission lines for electron cyclotron heating (ECH) of fusion plasmas. A low-power test at a frequency of 106.4 GHz has been carried out for several polarizers with different groove depths. The polarization characteristics experimentally measured are in good agreement with numerical results in which the actual groove shape functions are taken into account. This confirms the design optimization for future polarizer. Favorable results have also been obtained in a 400 kW-level high-power test for the polarizer installed in an ECH transmission line of the Heliotron-E plasma device.     

First paralytic shellfish poison (PSP) infestation of bivalves due to toxic dinoflagellate Alexandrium tamiyavanichii, in the southeast coasts of the Seto Inland Sea, Japan

The mussel Mytilus edulis and the cultured ark shell Anadara broughtonii in the southeast coasts of the Seto Inland Sea were contaminated with paralytic shellfish poison (PSP) following the appearance of the dinoflagellate Alexandrium tamiyavanichii in early December 1999. A. tamiyavanichii plankton collected around the Straits of Naruto on December 3, 1999 showed PSP toxicity, of which 83 mol% was accounted for by GTX2, GTX3 and GTX4. Its specific toxicity was 112.5 fmol/cell, and one MU was equivalent to 7,200 cells. Toxicity values at the beginning of toxification were 4.7 MU/g for the ark shell and 7.3 MU/g for the mussel. In the former, the value remained at almost 4 MU/g, resulting in prohibition of marketing for about two months. In the latter, it sharply decreased to less than 4 MU/g. These bivalves collected during the toxification period were dissected into five tissues, mantle, adductor muscle, hepatopancreas, gills and "others", and submitted to high-performance liquid chromatography (HPLC). The cultured ark shell accumulated GTX2, GTX3 and STX as major components and GTX1, GTX4, GTX5, neoSTX, dcSTX and PX1-3 (C1-C3) as minor ones. The amount of GTX3 decreased with time, while STX tended to increase. At the early stage of PSP toxification, toxins were accumulated in the gills and "others", most of which were quickly detoxified. On the other hand, PSP of the toxified mussel consisted of GTX4 as a main component, and GTX1, GTX2, GTX3, GTX5, STX and PX1-2 (C1-C2) as minor ones. Its toxin composition pattern was similar to that of the ingested causative plankton. Its total toxin decreased soon after disappearance of the dinoflagellate. During the decrease of toxicity, PSP tended to be retained in the hepatopancreas, resulting in accumulation of 50 mol% of total toxin.     

THIRD PHASE FORMATION IN NITRIC ACID EXTRACTION BYn-OCTYL(PHENYL)-N,N-DIISOBUTYLCARBAMOYL-METHYLPHOSPHINE OXIDE

ABSTRACT

The third phase formation was studied as a function of n-octyl(phenyl)-N, N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and tri-M-butyl phosphate (TBP) concentrations and temperature in the extraction of nitric acid. The concentration fractions of CMPO and TBP in the second and the third phases were determined by gas chromatography. Both CMPO and TBP were found to be enriched in the third phase. The concentrations of nitric acid in the second and the third phases relatively agreed with the calculated concentrations based on the extraction equilibrium constants of nitric acid by CMPO and TBP. The extraction of Np with the third phase formation was also discussed.     

THE SEPARATION OF NEPTUNIUM AND TECHNETIUM IN AN ADVANCED PUREX PROCESS

ABSTRACT

An advanced PUREX process has been developed which can reduce TRU waste volume and the environmental hazard risk due to long-lived nuclides. The separation of neptunium and technetium from plutonium and uranium solutions has been studied before the U/ Pu partitioning step in the PUREX process. The effectiveness of normal-butyraldehyde as a reductant of Np( VI) to Np( V) and of high acid scrubbing of technetium was shown in a basic study and a chemical flowsheet study.     

Periodical shedding of cloud cavitation from a single hydrofoil in high-speed cryogenic channel flow

In order to explain criteria for periodical shedding of the cloud cavitation, flow patterns of cavitation around a plano-convex hydrofoil were observed using a cryogenic cavitation tunnel of a blowdown type. Two hydrofoils of similarity of 20 and 60 mm in chord length with two test sections of 20 and 60 mm in width were prepared. Working fluids were water at ambient temperature, hot water and liquid nitrogen. The parameter range was varied between 0.3 and 1.4 for cavitation number, 9 and 17 m/sec for inlet flow velocity, and −8° and 8° for the flow incidence angle, respectively. At incidence angle 8°, that is, the convex surface being suction surface, periodical shedding of the whole cloud cavitation was observed on the convex surface under the specific condition with cavitation number and inlet flow velocity, respectively, 0.5, 9 m/sec for liquid nitrogen at 192°C and 1.4, 11 m/sec for water at 88°C, whereas under the supercavitation condition, it was not observable. Periodical shedding of cloud cavitation occurs only in the case that there are both the adverse pressure gradient and the slow flow region on the hydrofoil.     

Changes in symptom and thermography images after lumbar sympathetic ganglion block

In 35 lower limbs of 22 patients with peripheral circulation disturbance, we evaluated the effects of lumbar sympathetic ganglion block (LSGB) by skin temperature difference (delta T) between the two measured by thermography before and after LSGB. We divided the patients into two groups; ASO group (n = 15): patients with chronic arterial occulusive diseases, and nonASO group (n = 7): those with peripheral circulation disturbance partly due to decrease nervous function. After LSGB, we recognized a significant increase in delta T and remission of ischemic symptoms in all the patients of nonASO group and those in early stage of ASO group. This suggests that in ASO group LSGB should be applied as soon as possible to obtain good outcome, and thermography is useful to evaluate the effects of LSGB in patients with peripheral circulation disturbance of the lower limbs.     

The effect of cold working on creep rupture properties for helium-injected austenitic stainless steel

In order to study the effect of helium on the high temperature embrittlement of stainless steel, helium $\text{(7.5 × 10}{}^{\mathrm{?6}}\text{atomic fraction)}$ was injected into cold-worked stainless steels by using a cyclotron. At 650°C, it appeared that the reduction in creep-rupture strength due to helium was larger as cold-working was increased, but a loss of rupture elongation was less for a particular degree of cold-working. The 10% cold-worked material showed particularly good creep-rupture properties in the presence of helium. The loss of ductility was more pronounced in the creep test than in the tensile test.