Design optimization of tall tubular lead/acid cells based on an analysis of the reaction distribution

In order to estimate the discharge performance of tall lead/acid cells (with tubular positives), changes in current and potential distributions with discharge progress were calculated with a computer on the basis of plate resistance and the current—potential—time relationship between small facing parts of positive and negative plates. The taller the cell, the larger the voltage drop along the plates. Thus, the discharge time became shorter despite a large amount of available active mass remaining in the bottom part of the plates.Various current-collector designs were evaluated, e.g., one with varying resistance at each height; a side conductor placed along the plates and connected to them at the top, centre and bottom, etc. Results revealed an optimum collector design with which the maximum discharge capacity could be obtained. Furthermore, it was shown that the side conductor markedly improved the discharge performance because the active mass near the connecting parts was appreciably used.     

Discharge behaviour of electrodeposited PbO2 and Pb electrodes

The discharge behaviour of electrodeposited lead dioxide and lead electrodes was investigated under various conditions; the surfaces of the discharged electrodes were observed with a scanning electron microscope. Both the positive and negative electrodes were passivated by a covering of deposited lead sulphate crystals. The amount of lead sulphate required for passivation depended on the size of the crystals.     

SIGHT-A Dedicated Computer Graphics Machine

The. architecture of, and a performance estimate for, the dedicated graphics processor - SIGHT, a high-speed ray tracing machine, are presented. Ray tracing is a vector calculation in 3–dimensional (3–D) space and each ray to be traced can be calculated independently. The SIGHT is designed so that it speeds up the execution of the ray tracing algorithm at two levels of parallel operations: the pixel-level parallel operation by multiprocessors and the instruction-level parallel operation by the new processing element (PE) architecture. The features of the PE are:     

Study of local environment of Ag in Ag/CeO2 catalyst by EXAFS

The combustion synthesized Ag/CeO₂ catalysts have been characterized by Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy at the Ag K-edge. It has been found that Ag⁺ like species is present in 1% Ag/CeO₂ catalyst, whereas mostly Ag metal clusters are found in 3% Ag/CeO₂. The analysis of EXAFS spectra indicates that about one oxygen atom is coordinated to Ag central atom at a distance of 2.19 Å in 1% Ag/CeO₂ catalyst along with eight coordinated AgAg bond at 2.86 Å. The AgO bond is absent in 3% Ag/CeO₂.     

Review of pulmonary toxicity of indium compounds to animals and humans

Due to the increased production of ITO, the potential health hazards arising from occupational exposure to this material have attracted much attention. This review consists of three parts: 1) toxic effects of indium compounds on animals, 2) toxic effects of indium compounds on humans, and 3) recommendations for preventing exposure to indium compounds in the workplace.Available data have indicated that insoluble form of indium compounds, such as ITO, indium arsenide (InAs) and indium phosphide (InP), can be toxic to animals. Furthermore, InP has demonstrated clear evidence of carcinogenic potential in long-term inhalation studies using experimental animals. As for the dangers to humans, some data are available concerning adverse health effects to workers who have been exposed to indium-containing particles. The Japan Society for Occupational Health recommended the value of 3 μg/L of indium in serum as the occupational exposure limit based on biological monitoring to preventing adverse health effects in workers resulting from occupational exposure to indium compounds. Accordingly, it is essential that much greater attention is focused on human exposure to indium compounds, and precautions against possible exposure to indium compounds are most important with regard to health management among indium-handling workers.     

Anthropogenic lead inputs to the western Pacific during the 20th century

Unlike in the North Atlantic, no continuous record of anthropogenic lead (Pb) has been available in the western Pacific. We reconstructed historical changes in anthropogenic Pb on the basis of Pb isotope ratios recorded in annually-banded coral retrieved from Ogasawara Island, Japan. Whereas the predominant natural source of Pb to the surface of the western Pacific apparently is Chinese loess, anthropogenic Pb has affected the western Pacific at least since the late 19th century. From the late 19th to the early 20th century, Australian Pb used in Japan was an important source of anthropogenic Pb. During 1920-1940, Pb emitted from parts of the world other than Japan contributed somewhat to the western Pacific, and the amount of Pb imported from Australia declined. Alkyl Pb used in Japan became the main source from 1950 until the mid-1970s, when leaded gasoline began to be regulated in Japan. Since the mid-1980s, aerosols from China have been the predominant source of Pb in the western Pacific. During the 1990s, around 60% of Pb in the surface of the western Pacific was from Chinese aerosols. We also investigated the present spatial distribution and likely sources of Pb in the western Pacific by using coral samples. Enrichment in 208Pb, which is a characteristic of Pb from China, was found in all coral samples except that from Pohnpei, Micronesia, suggesting that at present anthropogenic Pb is transported to the western Pacific mainly from China via westerly winds.     

Allene as an alternative functional group for drug design: effect of C--C multiple bonds conjugated with quinazolines on the inhibition of EGFR tyrosine kinase

A series of allenic quinazolines were synthesized as receptor tyrosine kinase inhibitors by using a simple protocol for palladium-catalyzed allene transformation. Among the compounds synthesized, two allenic 4-anilinoquinazolines selectively suppressed epidermal growth factor receptor (EGFR) tyrosine kinase activity in vitro. According to immunoblot analysis, the allenic quinazolines inhibited the EGF-mediated phosphorylation of EGFR and its downstream kinases in A431 cells. Furthermore, one of these allenic quinazolines decreased the proliferation of A431 cells through the induction of cell-cycle arrest and apoptosis.