An articulated neurosurgical navigation system using MRI and CTimages

Neurosurgical operations sometimes involve difficulties in finding out the real positions of small-size neoplasms shown on tomographical images. The articulated navigation system, with the aid of a computer, gives ongoing positional correspondence between the position in the patient's brain and the one in the tomographic images to assist neurosurgery     

Biodegradation of Azo Acid Dyes by Continuous Cultivation of Pseudomonas Cepacia 13NA

The biodegradability of azo acid dyes by continuous cultivation of Pseudomonas cepacia 13NA, a bacterium able to assimilate azo dyes, was investigated as a means of improving the results of conventional biological treatments for the clarification of the waste dye liquor. It was found that all the acid dyes used were removed in high efficiencies compared with the conventional biological treatments. Multi-stage continuous cultivation in the poor nutrient conditions used proved to be particularly effective for acid dyes that otherwise would be difficult to degrade.     

Improvement of power system stability by on-off discrete control of series capacitors

Application of controlled series capacitors with anti-parallel thyristor combination across the capacitor segment is one of the new and promising countermeasures for enhancement of power system stability. The line reactance can be directly controlled by the controlled series capacitors, hence, it is very effective to apply the capacitors for damping power system disturbances. In this paper, we describe the following. (1) The design method of control system for the segmented series capacitors with thyristor switches is proposed. (2) The effectiveness of the controlled capacitors proposed for power system stabilization is shown with the results of EMTP analysis. (3) The possibility of zero passing missing phenomena of capacitor voltage is indicated by EMTP simulation, and a countermeasure is proposed in order to avoid the phenomena. The effects of the countermeasure is indicated by the results of EMTP simulation.     

Studies on the relationship between antioxidative activity of rice hull and germination ability of rice seeds

An investigation of the germination potentials of seeds of Indica and Japonica rice varieties revealed that while the long-life rice seeds retained the germination ability even on storage for a year at 30°C, the germination ability of the short-life rice seeds tended to decrease when stored beyond 6 months. The role of rice hull constituents in the preservation of the germination property during ageing of rice seeds was investigated with special emphasis on rice antioxidants. Antioxidative assay with chloroform-methanol and methanol-water extracts of hull, bran-germ and grain fractions of two Indica and five Japonica rice varieties indicated that all of the seed varieties belonging to Indica and Japonica possessed a strong antioxidative activity in the hull fraction. Hull extracts of long-life rice seeds showed relatively higher activities than those of short-life rice seeds. In contrast, hull extracts of long-life rice seeds had higher inhibitory effects on lipoxygenase activity than did those of short-life varieties. Quantification of the natural antioxidants indicated that ^α-tocopherol in rice oil to be present in the range of 318.3–450.1 μg g^?1 oil while the amount of oryzanol in the hull, bran-germ and grain fractions of rice was found to be 1.0–5.8, 95.4–279.8 and 3.0–9.4 μg g^?1 sample respectively. The results, however, did not show any positive correlation between the amount of natural antioxidants in rice hull and germination potentials of rice seeds. The amount of total phenolic constituents in rice hull was found to range from 190–390 μg g^?1 sample, the levels being far higher in long-life rice seeds in comparison with the short-life rice seeds. These values seemed to agree well with the germination data of the corresponding rice variety. The investigation revealed a strong influence of the level of phenolic constituents in rice hull on the storability of rice seeds.     

Characterization of the formation of α1plates from the β3phase in a Cu- Zn- Au alloy

The crystal structures and ordering structures of α₁ bainite plates and β₃ parent phase have been studied by means of electron microscopy in a Cu-40Zn-12Au (at. pct) alloy. The ordering transitions take place in the high-temperature β phase, and a stable L21 structure is reached even after direct quenching. The next-nearest-neighbor antiphase domains (NNNAPDs) are about 40 nm in size and have an island morphology surrounded by some nearly disordered regions. Wide isolated a, plates are present in 473 K aged microstructures, but at lower aging temperatures, thinner bainite plates tend to form in some coordinate modes. Reoriented second-stage thickening and stress-induced local thickening of thin a, plates have also been observed. Microanalysis of solute concentrations in thin bainite plates and in the matrix has shown the involvement of solute diffusion not only in the thickening process but also in the nucleating of the plate. Based on the results, an ordering facilitated shear mechanism is proposed for the a, bainite transformation, which can successfully explain its characteristics.     

Microheterogeneity of anion exchange membranes

Anion exchange membranes (ferricyanide ion type) prepared by the “paste method” were treated with an aqueous solution of hydrogen peroxide, and the resultant microporous membranes had no ion exchange capacity but water permeability. By measuring the water permeability of the membranes and observing the electron microphotographs of the membrane surfaces, it was elucidated that the anion exchange membranes contained microheterogeneity of colloidal dimension.     

Phase Transformation and Thermal Conductivity of Hot-Pressed Silicon Carbide Containing Alumina and Carbon

Phase transformation and thermal conductivity of hot-pressed β-SiC with Al₂O₃ and carbon additions were studied. Densification rate was a complex function of both Al₂O₃ and carbon. Simultaneous additions of Al₂O₃ and carbon accelerated the 3C → 4H phase transformation. Carbon additions lowered the thermal conductivity of the compact as did the high-temperature hot-pressing. The 3C → 4H transformation and the thermal conductivity were deduced to be related to each other.