Possibility of closed loop material recycling for fiber reinforced thermoplastic composites

It becomes significantly important to preserve ecological balance of the earth and protect the environment from getting worse. One of the urgent issues to be tackled will be to develop and establish recycling technology for polymeric composite materials. The expression of recycling technology in this case is that after the life of industrial products of fiber reinforced thermoplastic (FRTP) is completed, instead of being thrown away as wastes, they are reused as a raw material for new applications. An additional goal is that of saving valuable resources and not consuming further energy. This paper deals with a possibility of closed-loop recycling technologies for FRTP. The key factor is the fiber length which is expected to reduce in each recycling step. Materials tested here are continuous FRTPs, long FRTPs, short FRTPs, and powder reinforced plastics. The effect of fiber length on the reinforcing mechanism is first examined. The correlation between outdoor exposure test and accelerated weathering test is the second subject to covered. The third subject is to make clear the influence of crushing and heat history which are inevitable during each recycling stage. Throughout the above investigation, the concept of closed-loop recycling technologies has been established, although it is still in a preliminary stage.Abbreviations FRTP fiber reinforced thermoplastic - C-, L-, S-, P-FRTP continuous-, long-, short-FRTP, powder-RTP - FRP fiber reinforced thermosetting plastic - UD unidirectional - PP polypropylene - CF carbon fiber - GF glass fiber - V _f volume fraction of fiber     

E.s.r. study of vanadyl complexes in various carbonaceous materials at high temperature

E.s.r. spectra of vanadyl complexes in various carbonaceous materials were measured in a range between room temperature and 435 °C. The e.s.r. spectrum of vanadyl complex doped in Taching reduced crude was a slow tumbling pattern at temperatures between 60 °C and 225 °C. By the rapid freezing technique, it became clear that the vanadyl complex in Taching residue was oriented to the magnetic field in its temperature range. Further, activation energies for rotations of vanadyl complexes in those carbonaceous materials were estimated from Arrhenius plots of the correlation times. Those carbonaceous materials were classified into two groups according to values of the activation energies. This classification was consistent with that based on mesophase textures of the cokes made from them.     

Potentiation of pirarubicin activity in multidrug resistant cells by rifampicin

The effect of the anti-tuberculosis drug rifampicin on pirarubicin activity was investigated in multidrug-resistant cells overexpressing P-glycoprotein. Rifampicin increased the sensitivity of pirarubicin to anthracycline-resistant mouse leukemic P388 cells and significantly enhanced the cytotoxicity and intracellular accumulation of pirarubicin in resistant cells, but had no effect in parent cells. By contrast, two other rifamycins, rifamycin B and SV, had no effect on pirarubicin accumulation in resistant cells. Rifampicin also enhanced pirarubicin-induced apoptosis and G2/M blockade on the cell cycle in resistant cells. These results show that rifampicin enhances the cytotoxic action of pirarubicin in resistant cells, at least partly via the inhibition of cellular pirarubicin efflux.     

The bounded variation quantity (B.V.Q.) and its application to feature extraction

The concept of bounded variation quantity (B.V.Q.) is proposed as a local feature of patterns, especially waveform patterns and picture patterns. It is closely connected with the mathematically complicated concepts of total variation and distribution, but the result is shown by a simplified form (i.e. a summation of absolute differences) for concrete calculations. Its availability is also demonstrated through several applications such as seismic-wave analysis, the estimation of standard deviation in an independent Gaussian process and a method of detecting the directionality of picture patterns.     

Analysis of operational speed and scaling down the pixel size of acharge modulation device (CMD) image sensor

In a previous paper, the authors (ibid., vol.38, pp.989-998, May 1991) clarified the operational mechanism of a charge modulation device (CMD) image sensor and confirmed that numerical calculations using the transistor analysis program for imagers calculating non-steady-state equations (TRINE) predicted the actual performance of a CMD imager within a 20% discrepancy. Following these results, the scaling-down of device dimensions and the inherent operational speed are estimated using TRINE in order to realize a future high-resolution CMD image sensor. The analysis shows that a device size of 5.0 μm (H)×5.2 μm (V) is attainable without degrading the performance of the 10.2 μm (H)×10.4 μm (V) CMD imager and that the operational speed of a CMD is fast enough for a high-definition TV (HDTV) application which requires a scan rate of several tens of nanoseconds     

Organosilicon Derivatives of Buckminsterfullerene (C60): First Preparation of A Fullerene Silirane

C₆₀ reacts with photochemically generated bis(2,6-diisopropylphenyl)silylene (1) to give adducts, 2-4, as the isolable products. Spectroscopic analysis and theoretical investigation strongly support the silirane structure 2a, and not the isomeric 1,6-silamethano[10]annulene 2b.