Real-time PCB monitoring using time-of-flight mass spectrometry with picosecond laser ionization

The study demonstrates the applicability of laser ionization time-of-flight mass spectrometry for real-time measurement of polychlorinated biphenyls (PCBs). Picosecond 266-nm laser light ionization reduced fragmentation and provided very high PCB detection sensitivity. This high sensitivity has advantages in terms of real-time monitoring capability as compared to the conventional GC-ECD or GC-MS methods, which require at least several days for the analysis of PCBs. Detection sensitivity of under 0.01 mg/Nm3 was achieved with a 1-min measuring time; this sensitivity is superior to the exhaust gas control guideline of 0.15 mg/Nm3 by a factor of 10. A prototype PCB monitoring device has been developed and tested in a pilot PCB treatment plant. The 1-min detection time represents a substantial advance in the monitoring of exhaust gas and the workplace atmosphere in accordance with safety regulations.     

Role of phosphatidylinositol 3-phosphate in formation of forespore membrane in Schizosaccharomyces pombe

Phosphatidylinositol (PI) 3-kinase (encoded by the pik3(+) gene) in Schizosaccharomyces pombe has been identified as a homologue of VPS34p, a protein required for proper vesicular protein sorting. The clone defective in this protein carries enlarged vacuoles and exhibits sensitivity to high temperature or high ion concentration. The effect of disruption of pik3(+) on sporulation of Sz. pombe was examined. The diploid cells underwent G(1) arrest and meiosis. However, the spores formed by the deltapik3 cells were not viable. Electron-microscopic analysis revealed that the growth of the forespore membrane of deltapik3 cells was not correctly orientated, failing to engulf the nucleus or forming extremely small spores, as was confirmed by the use of Spo3p-GFP and GFP-Psy1p, which are markers of the forespore membrane. The coating materials found along the forespore membrane of the wild-type were greatly reduced in these cells. PI 3-P, the product of Pik3p, was detected on the forespore membrane, suggesting that PI 3-P-dependent vesicle transport may take place in formation of the forespore membrane. Misshaped forespore membrane, accumulation of vesicles, formation of small non-viable spores, and suppression by over expression of Psy1p were the phenotypes commonly seen in deltapik3 and deltaspo3 cells, suggesting a relationship between the functions of Pik3p and Spo3p in formation of the forespore membrane in Sz. pombe.     

氧空穴在 BaMgAl10O17荧光粉的能量转移过程中的作用

研究不掺杂和掺 Eu 的 BaMgAl10O17(BAM)荧光粉在真空紫外激发的光致发光(PL)、热致发光(TL)性能.研究发现不掺杂的BAM发射的空穴与缺陷产生的电子陷阱有很大的关系.我们认为这些缺陷与BAM空穴导电层的氧空穴有关.我们还认为掺了 Eu2 的BAM主体存在着缺陷.基于这些结果,我们提出了一种真空紫外激发 BAM:Eu2 荧光粉的能量转移模型.     

Selectively stimulating skin receptors for tactile display

Research in virtual reality has recognized the need for more realistic tactile display in addition to touch and non-touch display and force display. We propose a method of selectively stimulating only superficial mechanoreceptors. We show that it makes people feel a more realistic, finer virtual texture than possible by adjusting the stimulator spacing. The apparatus is simple and we expect this idea to develop into a device to display varieties of tactile feeling     

APPLICATION OF H∞ CONTROL AND CLOSED LOOP IDENTIFICATION TO A MAGNETIC LEVITATION SYSTEM

A systematic procedure for modeling and robust control of a multivariable magnetic levitation system is described. Our previous study revealed that an observer-based LQ controller can stabilize the system, but generates spillovers in the presence of an impulse disturbance. To solve this problem, we apply an H_∞ control to suppress the spillovers caused by unmodeled dynamics which we estimate using closed loop identification. First, an exactly linearized model is obtained to compensate for nonlinearities in the system, followed by estimation of the unmodeled dynamics using closed loop identification. Second, this information is used to design a two degree of freedom H_∞ servo system for suppressing the spillover while tracking a step reference input. Finally, the desired robust performance of the resulting servo system is confirmed theoretically by γ-analysis and also experimentally.