DRYING OF FINE CERAMICS

The drying mechanism of shaped ceramics is reviewed and some methods for eliminating defects produced by drying are discussed in this report. The types of defects depend upon the shaping method, shape, properties of the raw materials, drying process and other items. Most defects of dried ceramics are produced during the initial or middle drying stage when large shrinkage of the ceramic body occurs. These defects may be successfully eliminated by heating the body from the inside. Self-deformation caused by weight is also a serious defect. The near net shaping of fine ceramics to reduce machining requires uniform body shrinkage and hence, highly controlled drying. Examples of electric current drying, dielectric drying, and dewaxing are also shown in this report.     

Robots in Japan: present and future

The would-wide slackening of business activities appears to have also slowed the pace of the industrial robot business. It is often said that we are now entering an epoch where the industrial robot is to be succeeded by the "service robot". The designation "service robot," however still remains to be clearly defined. As yet, the image evoked by this term varies very widely from person to person, in both the external appearance and the technological elements that constitute such a robot. The author considers the term service robot to be a generic term covering all robots that are not for industrial use. The author looks at the development of service robots in Japan     

Spectrophotometric and electron spin resonance studies on the chloro complexes of manganese (II), cobalt (II) and copper (II) in solvent extraction by trioctylamine and trioctylmethylamrnonium chloride

The complexes of bivalent manganese, cobalt and copper formed in the extraction from hydrochloric acid solutions by trioctylamine (TOA, R₃N) and trioctylmethylammonium chloride (Aliquat-336, R₃R'NCl) in benzene have been examined by spectrophotometry and electron spin resonance spectroscopy. It was found that the moiety MCl^2-₄ in all complexes studied had a tetrahedral geometry, and that the M-Cl bond in the species (R₃R′N)₂MCl₄ was rather more ionic than that in the species (R₃NH)₂MCl₄, in which M = Mn, Co and Cu.     

Analysis of longitudinal viewing freedom of reduced‐view super multi‐view display and increased longitudinal viewing freedom using eye‐tracking technique

Abstract— The viewing freedom of the reduced‐view super multi‐view (SMV) display was analyzed. It was found that there are separate multiple viewing ranges in the depth direction; thus, a technique that selects an appropriate viewing range to increase the longitudinal viewing freedom has been developed. Pixels of a flat‐panel display viewed by the viewer's eyes through a lenticular lens were determined from three‐dimensional (3‐D) positions of the viewer's eyes, which were obtained using an eye‐tracking system that employed a stereo camera. Parallax images corresponding to the 3‐D positions of the viewer's eyes were generated, which were displayed by the determined pixels. The experimental results show that the proposed technique successfully increased the longitudinal viewing freedom. It is also shown that a video camera was able to focus on the produced SMV images.     

Controlled degradation of polystyrene

For the purpose of efficient utilization of waste polystyrene, the recovery method of a styrene oligomer having a molecular weight of 1000–3000 was studied. Thermal and catalytic degradations were carried out. It was impossible to obtain a styrene oligomer with a molecular weight less than 5000 by thermal degradation in the temperature range of 300–500°C. Catalytic degradation in the presence of silica–alumina catalyst in the temperature range of 190–230°C made it possible to control the decrease in molecular weight and to obtain a styrene oligomer having a molecular weight of 500–3000. Simultaneously, the molecular structures of the reaction products from thermal and catalytic degradations were determined by NMR analysis.     

ESCA study of the passive film on an extremely corrosion-resistant amorphous iron alloy

X-ray photoelectron spectroscopy was applied to study the composition of the passive film formed on an extremely corrosion resistant amorphous Fe-10at.%Cr-13at.%P-7at.%C alloy in 1 N HCl. The passive film consists mainly of hydrated chromium oxyhydroxide which is a common major constituent of passive films on crystalline stainless steels. The extremely high corrosion resistance of the amorphous alloy can only in part be attributed to the formation of a protective hydrated chromium oxyhydroxide film.     

Thermodynamic assessment of the Cu−Pt system

A CALPHAD assessment of the Cu−Pt system has been carried out. Two and four sublattice models were applied to describe the Gibbs free energies of ordered phases where the contribution of SRO is taken explicity into account through the reciprocal parameters. The disordered fcc A1 and liquid phases were treated as substitutional solutions. A consistent set of parameters for the phases in the Cu−Pt system as obtained, and those parameters can satisfactorily reproduce the experimental phase equilibria and thermodynamic properties, such as enthalpies, activity of Cu, and long-range order parameters. This paper was presented at the International Symposium on User Aspects of Phase Diagrams. Materials Solutions Conference and Exposition, Columbus, Ohio, 18–20 October, 2004.     

Synthesis of ternary intercalation compounds of carbon fiber

Ternary intercalation compounds of carbon fiber (ICCF) were successfully synthesized by soaking pitch-based carbon fibers in solvents such as 1,2-dimethoxyethane (DME) or tetrahydrofuran (THF) containing dissolved alkali metals (lithium, sodium, or potassium). ICCF with stage-1 and random stage was synthesized in alkali metal–DME and potassium–THF systems using different types of carbon fibers. However, ICCF with stage-1 could not be synthesized in lithium– or sodium–THF systems using carbon fibers with a low graphitization degree. Furthermore, the influence of the graphitization degree in the synthesis of ICCF was discussed. The graphitization degree of the host carbon fiber, in addition to the dimensions and steric structure of the intercalated complex affected the formation of TICCF.     

Syngas to iso-paraffins over Co/SiO2 combined with metal/zeolite catalysts

Selective production of gasoline ranged iso-paraffins from synthesis gas was performed in a consecutive dual reactor system, in which Fischer–Tropsch reaction was carried out over Co/SiO₂ catalyst in the upper reactor and hydroconversion of the Fischer–Tropsch hydrocarbons occurred over precious metal/zeolite catalyst in the lower reactor. Results indicate that the product distribution of traditional Fischer–Tropsch synthesis was significantly modified and high selectivity to iso-paraffins was achieved with the presence of metal/zeolite catalyst in the lower reactor. A significant effect of metals (Pt and Pd), zeolites (zeolites of β and USY), and the preparation methods (impregnation and ion exchange) of the metal/zeolite catalyst on the iso-paraffins selectivity and product distribution was clearly observed. This was explained based on the property of the metal for hydrogen spillover and the acidic and structural properties of the zeolite in the bifunctional metal/zeolite catalyst.