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<div> <p>The objective of this thesis is to apply high frequency flow measurement technique known as hot wire anemometry to <a>characterize the velocity, turbulence intensity and turbulent length scales in the </a><a></a><a>Purdue Experimental Turbine Aerothermal Lab Rig</a>. Hot wire anemometry has been widely used to characterize velocities and turbulence levels in different environments and using different calibration and post-processing methodologies. In this work, a precise calibration and post-processing method was developed and successfully applied to the state-of-the-art trisonic Purdue Experimental Turbine Aerothermal Lab wind tunnel. The different experimental setups where the turbulence levels were analyzed were fabricated using modern manufacturing techniques such as 3D printing or water cutting. These techniques increase the complexity of the designs to be tested in wind tunnels. Calibration process was then successfully tested in the Purdue Experimental Turbine Aerothermal Lab Rig. Finally, accuracy and sensitivity analysis of the calibration are performed to verify the performance and reliability of the process.</p></div>

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 134-144). Also available in electronic version.

Structural determinations and electrochemical properties in the series of multinuclear ferrocenyl¡Vethynyl complexes with formula [(£b5-C5H5)(P2)MII-C¡ÝC-(fc)n-C¡ÝC-MII(P2)(£b5-C5H5)] (fc = ferrocenyl; M = Fe(II), Os(II); P2 = Ph2PCH2CH2PPh2 (dppe)) are reported. These complexes undergo sequential reversible oxidation events from 0.0 to 1.0 V referred to the Ag/AgCl electrode in anhydrous CH2Cl2 solution and the low-potential waves have been assigned to the two end-capped metallic centers. The magnitude of the electronic coupling between the two terminal metallic centers in the series of complexes was estimated by the electrochemical technique. Based on the correlation between the ¡µE1/2 values and the second redox potentials of the end-capping metallic centers in the series of complexes, a qualitative explanation for the difference of the electronic coupling is given. Furthermore, we attempt to fabricate the SAMs of ferrocenyl-ethynyl molecules on gold surface and confirmed by XPS spectrum and the RAIR spectrum. CV and CA electrochemistry technique was employed in studied electron transfer rate (k).

In this paper, there are two major investments consisted of ¡§Failure Mechanism of Inner Lead Au-Sn Bonds in Tape Automated Bonding (TCP) Packages¡¨ and ¡§Cu Wire bond microstructure analysis and failure mechanism¡¨. In view of the advantages of low cost, simple manufacturing process and significant miniaturization in size, TCP technology is widely applied in consumer electronic products. Inner lead bonding (ILB) process is especially crucial for the production of high quality TCP packages and components. The ILB process is extremely dynamic since the bonding time is around 0.2 second to complete the thermo-compress and soldering processes. The composition of liquid pool varied with the bond temperature and pressure and is crucial to exhibit different structure. One type of unusual failure bond happened during the process parameters optimization. ILB joints microstructure was examined by electron microprobe (EPMA) for detail phase analysis. The phase formation sequence of normal and failure bonds can be explained from the Au-Sn-Cu ternary phase diagram and thermo-chemistry data of Au-Sn binary. According to Part I study, the hypo-eutectic composition (<30 at% Sn) liquid pool could maintain the normal ILB bonds. And the hyper-eutectic composition (>30 at% Sn) has the potential risk to form this unusual failure bond. In the Part II study, copper wire bonding samples were aged at 205¢XC in air from 0 h to 2000 h. It was found that the bonding of a Cu wire and an Al pad formed Cu9Al4, CuAl, and CuAl2 intermetallic compounds, and an initial crack was formed by the ultrasonic squeeze effect during thermosonic wire bonding. The cracks grew towards the ball bond center with an increase in the aging time, and the Cl ions diffused through the crack into the ball center. This diffusion caused a corrosion reaction between the Cl ions and the Cu-Al intermetallic phases, which in turn caused copper wire bonding damage.

The preparations of multinuclear supramolecules assembled from 1,1¡¬-bis(terpyridyl)ferrocene, 1,1¡¬-bis(terpyridyl)biferrocene and 1,1¡¬-bis(terpyridyl)triferrocene (tpy-(fc)n-tpy, n =1-3) redox-active moieties with Ru2+ metal centers are described. The electrochemical measurements of the Ru2+ coordinated tpy-(fc)n-tpy complexes (1a (n=1); 1b (n=2); 1c (n=3)) are dominated by the Ru2+/Ru3+ redox couple (E1/2 from 1.35 to 1.38 V), Fe2+/Fe3+ redox couples (E1/2 from ∼0.4 to ∼1.0 V) and tpy/tpy-/tpy2- redox couples (E1/2 from 1.3 to 1.5 V). The appreciable variations detected in the Fe2+/Fe3+ oxidation potentials indicate that there is an interaction between the spacer and the Ru2+ metal centers. On the coordination of Ru2+ metal centers with tpy-(fc)n-tpy rises to a red-shifted and more intense 1[(d(£k)Fe)6] ¡÷ 1[d(£k)Fe)5(£k*tpyRu)1] transition in the visible region. The observed red-shifted absorption from 526 nm in monomeric [Ru(fctpy)2]2+ complex to ~560 nm in 1b and 1c reveals that there is a qualitative electronic coupling within the ferrocenyl array. The Fe-Fe interactions result in a red characteristic of the 1[(d(£k)Fe)6] ¡÷ 1[d(£k)Fe)5(£k*tpyRu)1] MMLCT transition.

The development of molecular wires where photoactive and electroactive terminals are linked by a large size molecular spacer may open new path in the field of storage and utilization of light energy. An important issue concerns how best to design the spacer that permit controlled transfer of electron along the molecular axis. Our design principle for a molecular wire has to fulfill following criteria : (i) an organometallic redox-active spacer to enhance the capability of transfer information along the molecular axis and (ii) modular synthetic approach to control length. The preparations of multinuclear supramolecular assembled from redox-active biferrocencyl spacer and ruthenium(II) terpyridine chromophore are described. Interestingly, substitution of a methoxy group on terminal terpyridine 4'-position of complex 13 will enhance the electronic coupling between the spacer and Ru2+ metal centers. The detailed properties about complex 13 are described in electrochemical results, UV-visible spectral data, and photo luminescent investigation.

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The synthesis and characterizations together with the electrochemical behavior, UV-Vis spectroscopy, and photophysical properties of the multinuclear supramolecule assembled from the 1,1'-bis(terpyridylethynyl)triferrocene (tpy-C¡ÝC-(fc)3-C¡ÝC-tpy) redox-active spacer with ruthenium centers are described.

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