Effect Of Metal Particles Research Articles

Optical properties of silver, gold and aluminum ultra-thin granular films evaporated on oxidized aluminum

The reflectivity of silver, gold and aluminum granular ultra-thin films deposited on an oxidized aluminum substrate has been measured in a spectral range from 300 to 700 nm. This measurement was done at 45° with p-polarized light, during the deposition of the different metals and also after a 300°C annealing at the end of the evaporation process. Some measurements were also performed in air at different incidence angles with p- and s-polarized light. Plasmon resonance effects of metal particles are seen directly in the reflectivity spectrum.

DC Dielectric Characteristics and Conception of Insulation Design for DC GIS

In order to discuss the dielectric performance of DC GIS, the flashover characteristics of gas-insulated bus were studied under conical- and disk-type spacers. The test involves the investigation on effect of electrification for charge to be accumulated in spacers and the effect of metallic particles. As the result, it was found that the dielectric characteristics of conical-type spacer are better than disk type. Moreover, the dielectric performance of DC GIS is more affected by the characteristics of coaxial electrode system than spacer surface with regard to metallic particle. On the basis of the results of these tests, this report presents the conception of insulation design for DC GIS.

Sol—gel preparation and photoelectrochemical properties of TiO 2 films containing Au and Ag metal particles

TiO 2 film electrodes with a TiO 2 overlayer containing dispersed Au or Ag metal particles were prepared by the sol-gel method, and the effect of the metal particles on the photoelectrochemical properties of the TiO 2 electrodes were investigated. An increase in the anodic photocurrent in the visible region was observed for both the Au and Ag particle dispersed electrodes, which was thought to result from the surface plasma resonance of the metal particles. The introduction of Au metal particles, however, reduced the anodic photocurrent in the ultraviolet region, resulting in a decrease of the anodic photocurrent under the illumination of xenon lamp light. On the other hand, for the Ag particle dispersed electrodes, the anodic photocurrent in the ultraviolet region increased and then decreased with an increasing amount of Ag particles. These effects of the dispersed metal particles on the photoelectrochemical properties of the TiO 2 electrodes were explained on the basis of the band models.

DC dielectric characteristics and conception of insulation design for DC GIS

In order to discuss the dielectric performance of DC GIS, the flashover characteristics of gas-insulated bus were studied under conical- and disk-type spacers. The test involves the investigation on effect of electrification for charge to be accumulated in spacers and the effect of metallic particles. As the result, it was found that the dielectric characteristics of conical-type spacer are better than disk type. Moreover, the dielectric performance of DC GIS is more affected by the characteristics of coaxial electrode system than spacer surface with regard to metallic particle. On the basis of the results of these tests, this report presents the conception of insulation design for DC GIS.

Effects of Metal Particles and Ions on the Biological System

Effects of Metal Particles and Ions on the Biological System

The effect of metal particles from a nickel refinery dump on alveolar macrophages. Part 1—Chamber exposure of Wistar rats

The effect of long-term respiratory chamber exposure to aerosol containing metal particles derived from a nickel refinery dump on the alveolar macrophage (AM) phagocytic and enzymatic activities of Wistar rats was investigated. The number of AM lavaged from the lungs of the exposed group was significantly higher than in the controls (P < 0·001). The lung lavage exhibited some pleomorphic cells. The high number (93%) of AM with phagocytised metal particles was detected. In vitro the lavaged cells showed a significant increase in 51Cr incorporation compared to the control group. A statistically significant enhancement of AM lysosomal (acid phosphatase and β-glucuronidase) enzyme activities (P < 0·05, P < 0·01) was found in the exposed animals, whereas both the plasma membrane (ATPase and 5′-nucleotidase) enzyme activities were clearly reduced (P < 0·001). Serum cytotoxicity in the exposed animals was slightly elevated.