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Wire mesh dampers are under investigation because they are seen as replacements for squeeze film dampers as a source of direct stiffness and damping at bearing locations. There are several advantages of wire mesh dampers over squeeze film dampers, including: temperature insensitivity, oil-free operation, and the ability to contain large amplitude vibrations. Furthermore, due to their direct damping and lack of cross-coupled stiffness, the wire mesh reduces the response to imbalance and increases the stability of the system. The objective of this research was to determine the properties of wire mesh dampers under large amplitude vibrations. Impact testing was first conducted on the wire mesh as a means of obtaining the large amplitudes that were of interest. Next, to verify the results, a second methodology was employed using shaker testing. It was found that both the stiffness and hysteretic damping decrease with increasing displacement. However, they both approached asymptotes around 2 mils of displacement, and further increases in displacement had significantly less effect on the properties. Once the results were verified to be consistent, equations were obtained to describe the response of the wire mesh dampers. These equations were then used to create a new design workbook, which would allow an engineer to determine the properties of wire mesh dampers under conditions that they might experience.

Recently, wirebonding process play an important role in IC assembly packaging manufacture. No degradation of bonding wire interconnection and defect free eutectic alloy bonding offer the high yield and reliability of products. The degradation of Au wire/Al bond pad has become a major bonding failure problem. By utilizing the SEM, AES, EDS and XPS techniques, it could be carried out to reveal and identify defects underneath Al layer, and the contaminated Al bond pads could cause poor intermetallic growths led to the failed or unreliable connections from the chip to the outside world. It is because that the molding resin with low thermal stability (e.g. bi-phenyl epoxy resin) and the IC devices under high thermal environments were used in packaging process. For the lifetime to bond failure, the bi-phenyl epoxy molding becomes shorter than that for cresol novolac epoxy due to the corrosion reaction of Au-Al intermetallics with bromine (Br) contained in the resin compounds. It was clarified that the reactive intermetallic was Au4Al phase formed in the bond interface.

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Wire mesh dampers are under investigation because they are seen as replacements for squeeze film dampers as a source of direct stiffness and damping at bearing locations. There are several advantages of wire mesh dampers over squeeze film dampers, including: temperature insensitivity, oil-free operation, and the ability to contain large amplitude vibrations. Furthermore, due to their direct damping and lack of cross-coupled stiffness, the wire mesh reduces the response to imbalance and increases the stability of the system. The objective of this research was to determine the properties of wire mesh dampers under large amplitude vibrations. Impact testing was first conducted on the wire mesh as a means of obtaining the large amplitudes that were of interest. Next, to verify the results, a second methodology was employed using shaker testing. It was found that both the stiffness and hysteretic damping decrease with increasing displacement. However, they both approached asymptotes around 2 mils of displacement, and further increases in displacement had significantly less effect on the properties. Once the results were verified to be consistent, equations were obtained to describe the response of the wire mesh dampers. These equations were then used to create a new design workbook, which would allow an engineer to determine the properties of wire mesh dampers under conditions that they might experience.

In attempting to modulate the electronic properties of molecular-wire Ru(II) complexes, we now describe an interesting example of X-tpy-Ru2+-tpy-(fc)2-tpy-Ru2+-tpy -X ( fc = ferrocenyl ; tpy = terpyridyl ; X=Cl, OMe, OH ) complexes comprising electronic donor or withdrawing group attached directly to the 4¡¦-position of the terminal tpy moiety. The ground-state HOMO and LUMO energies were probed by electrochemical measurements and the excited-state photophysical properties were probed by absorption spectroscopy.

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