Noninvasive subsurface analysis using multiple miniaturized Raman probes, part I: basic study of thin-layered transparent models of biomedical tissues

This study describes a basic theory for reconstructing pure Raman signals of materials composing a multilayer sample from Raman spectra obtained using two types of miniaturized Raman probes. An illustrative example is demonstrated using a multilayer system of samples composed of the transparent plastics polymethylmethacrylate (PMMA) and polyethylene (PE) as a model of thin-layered biomedical tissues. When the same region of an object is measured using Raman probes with different focal properties, the Raman spectra provide different depth profile information depending on the level of light penetration. Thus, a detailed comparison of the spectra can provide an interesting opportunity to probe the differences between the layers. A simple analytic form is presented for reconstructing the pure Raman spectra of the embedded layer. The method applies an understanding of the Raman sampling volume in layered transparent materials to the interpretation of Raman spectra experimentally measured by multiple probes. The basic theory described here is necessary for the expansion of the technique to turbid media, such as biological samples, where light-scattering effects must be considered. The potential applications of the proposed method include material and catalyst subsurface probing through different embedded materials, such as assessment of silicon wafers, effective noninvasive screening for catalyst synthesis, and biomedical tissue research.     

Breakdown Trade-Off Relation of Mechanical Properties via Micro-alloying in Mg–Mn Alloys

The impact of micro-alloying on tensile behavior at strain rates in various ranges is examined using five types of extruded Mg-0.3 at. pct Mn–0.1 at. pct X ternary alloys, where X is selected as a common element, Al, Li, Sn, Y or Zn. Microstructural observations reveal that the average grain size of these extruded alloys is between 1 and 3 μm, and these micro-alloying elements segregate at grain boundaries. In room temperature tensile and compression tests, these results show that the mechanical properties and deformation behavior are influenced by the micro-alloying element, even as a small addition of 0.1 at. pct. Mg–Mn–Y and Mg–Mn-Zn alloys show higher strength and smaller strain rate sensitivity (m-value) among the present alloys, owing to the rate-controlling mechanism as dislocation slip. On the other hand, the Mg–Mn–Li alloy exhibits the largest elongation to failure in tension and the highest strain rate sensitivity, associated with high contribution of grain boundary sliding to deformation. These differences are due to the grain boundary segregation of the micro-alloying elements. Compared to the common Mg alloys, the present ternary alloys also show a trade-off relationship between strength and ductility, which is similar to that of the well-known Mg alloys; however, these properties of the Mg–Mn system ternary alloys could be controlled via the type of micro-alloying elements with a chemical content of 0.1 at. pct.

     

The use of intravenous immunoglobulin in Miller Fisher syndrome

We report a patient with Miller Fisher syndrome who was treated with an intravenous high-dose of immunoglobulin. This syndrome is considered to be a benign variety of acute inflammatory demyelinating polyneuropathy (Guillain-Barré syndrome). However, there have been several reports of the need for ventilatory support and a few cases have had a fatal outcome. We observed a case of progressive Miller Fisher syndrome in a 3-year-old boy. Following 2 episodes of apnea lasting about 50 s each, he was treated with intravenous immunoglobulin (400 mg/kg/day) for 5 consecutive days. His respiratory state, general muscle strength, truncal ataxia and emotional state improved remarkably after this therapy.     

Studies on the method of combining an analog simulator and a real‐time digital simulator for power system analysis

An advanced real‐time power system simulator consisting of a conventional real‐time analog simulator and a real‐time digital simulator has been developed. EMTP simulations were carried out to verify the advanced power system simulator concept and to evaluate the effects of various parameters. A prototype of the advanced power system simulator using the Bergeron method was tested. The test results confirmed the feasibility of the real‐time power system simulator. © 2001 Scripta Technica, Electr Eng Jpn, 136(3): 49–57, 2001     

A unified adaptive oculomotor control model

In order to understand mechanisms of oculomotor control systems, an oculomotor model based on eye's anatomical structure and physiological mechanism is developed. In this model, various types of eye movements are considered, and two learning systems, one based on adaptive characteristics of flocculus and the other on vestibular nuclei's are developed. The role of neural paths from ocular muscle stretch receptors into flocculus, which were thought to not contribute in eye movement, is discussed in detail from the viewpoint of system control engineering. The experimental results through simulation show good control performance of the proposed model. Copyright © 2001 John Wiley & Sons, Ltd.     

Activity of alumina-supported molybdenum nitride for carbazole hydrodenitrogenation

The alumina-supported molybdenum nitride catalyst was extremely active in the hydrodenitrogenation of carbazole at 553–633 K and 10.1 MPa total pressure when compared with the sulfided and reduced catalysts.     

Spatial Distribution of Ions in Groundwater under Agricultural Land

This study investigated the characteristics of shallow groundwater quality under agricultural areas dominated by rice paddy fields, vegetable fields, and a residential zone on an alluvial basin by examining spatial distributions of Cl?, Na+, NO3?, and SO42? concentrations. Seasonal changes in spatial distribution of ion concentrations during one cultivation period and the causes of the changes were discussed. Changes in spatial distribution of Cl? and Na+ concentrations of the groundwater were mainly affected by seasonal changes in precipitation concentrations. NO3? concentration was strongly influenced by fertilization of vegetable fields and a following heavy rainfall. Elevated NO3? concentration was less likely to occur under paddy fields than under vegetable fields. It was suggested that paddy fields might mitigate NO3? contamination of shallow groundwater possibly because of denitrification in paddy soil in an anaerobic state during ponding. As for SO42?, it was acknowledged that there could be a specific point source near a particular observation well.